WorldWideScience

Sample records for calibrators tandem systems

  1. Development of dose calibrators Tandem systems and establishment of beta dosimetry in nuclear medicine

    International Nuclear Information System (INIS)

    A quality control program at Nuclear Medicine Services includes the checking of all equipment used for diagnostics and treatment, and the individual monitoring of the workers occupationally exposed to ionizing radiations. In this work the main quality control tests were performed with three dose calibrators using standard radiation sources of 57Co, 133Ba, 137Cs and 60Co. Tandem systems of dose calibrators were established and characterized using four cylindrical absorbers of different materials for an additional quality control test in Nuclear Medicine. The main utility of this new test is the possibility of impurity detection in radiopharmaceuticals, when the ratio of the measurements with different absorbers is different from that obtained at the laboratory in ideal conditions. The dosimetric characteristics of three types of CaS04:Dy + Teflon pellets were studied for an appropriate choice of the material to be used for individual monitoring of workers. The thermoluminescent detectors were irradiated using beta sources of 90Sr+90Y, 204TI, 147Pm, 153Sm and 32P. A wrist badge for beta individual monitoring was developed for workers that handle beta radiopharmaceuticals in Nuclear Medicine Services. (author)

  2. Tandem mobile robot system

    Science.gov (United States)

    Buttz, James H.; Shirey, David L.; Hayward, David R.

    2003-01-01

    A robotic vehicle system for terrain navigation mobility provides a way to climb stairs, cross crevices, and navigate across difficult terrain by coupling two or more mobile robots with a coupling device and controlling the robots cooperatively in tandem.

  3. The GERDA calibration system

    International Nuclear Information System (INIS)

    A system with three identical custom made units is used for the energy calibration of the GERDA Ge diodes. To perform a calibration the 228Th sources are lowered from the parking positions at the top of the cryostat. Their positions are measured by two independent modules. One, the incremental encoder, counts the holes in the perforated steel band holding the sources, the other measures the drive shaft's angular position even if not powered. The system can be controlled remotely by a Labview program. The calibration data is analyzed by an iterative calibration algorithm determining the calibration functions for different energy reconstruction algorithms and the resolution of several peaks in the 228Th spectrum is determined. A Monte Carlo simulation using the GERDA simulation software MAGE has been performed to determine the background induced by the sources in the parking positions.

  4. Measurement System & Calibration report

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    This Measurement System & Calibration report is describing DTU’s measurement system installed at a specific wind turbine. A major part of the sensors has been installed by others (see [1]) the rest of the sensors have been installed by DTU. The results of the measurements, described in this report...

  5. Establishment of a tandem ionization chamber system in standard mammography beams

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jonas O. da; Caldas, L.V.E., E-mail: jonas.silva@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    A double-faced tandem ionization chamber system was developed at the Calibration Laboratory of IPEN. It has different collecting electrode materials: aluminium and graphite. The response repeatability and reproducibility and the energy dependence test of this tandem ionization chamber were evaluated. The chamber response stability is within the {+-}3% limit recommended in international standards. The energy dependence test of the ionization chamber system using the tandem curve obtained, presented agreement with literature results. (author)

  6. Packet models revisited: tandem and priority systems

    NARCIS (Netherlands)

    Mandjes, M.R.H.

    2004-01-01

    We examine two extensions of traditional single-node packet-scale queueing models: tandem networks and (strict) priority systems. Two generic input processes are considered: periodic and Poisson arrivals. For the two-node tandem, an exact expression is derived for the joint distribution of the total

  7. Packet models revisited: tandem and priority systems

    NARCIS (Netherlands)

    M.R.H. Mandjes

    2004-01-01

    Abstract : We examine two extensions of traditional single-node packet-scale queueing models: tandem networks and (strict) priority systems. Two generic input processes are considered: periodic and Poisson arrivals. For the two-node tandem, an exact expression is derived for the joint distribution o

  8. The Calibration Reference Data System

    Science.gov (United States)

    Greenfield, P.; Miller, T.

    2016-07-01

    We describe a software architecture and implementation for using rules to determine which calibration files are appropriate for calibrating a given observation. This new system, the Calibration Reference Data System (CRDS), replaces what had been previously used for the Hubble Space Telescope (HST) calibration pipelines, the Calibration Database System (CDBS). CRDS will be used for the James Webb Space Telescope (JWST) calibration pipelines, and is currently being used for HST calibration pipelines. CRDS can be easily generalized for use in similar applications that need a rules-based system for selecting the appropriate item for a given dataset; we give some examples of such generalizations that will likely be used for JWST. The core functionality of the Calibration Reference Data System is available under an Open Source license. CRDS is briefly contrasted with a sampling of other similar systems used at other observatories.

  9. Tandem Mirror Reactor Systems Code (Version I)

    International Nuclear Information System (INIS)

    A computer code was developed to model a Tandem Mirror Reactor. Ths is the first Tandem Mirror Reactor model to couple, in detail, the highly linked physics, magnetics, and neutronic analysis into a single code. This report describes the code architecture, provides a summary description of the modules comprising the code, and includes an example execution of the Tandem Mirror Reactor Systems Code. Results from this code for two sensitivity studies are also included. These studies are: (1) to determine the impact of center cell plasma radius, length, and ion temperature on reactor cost and performance at constant fusion power; and (2) to determine the impact of reactor power level on cost

  10. A variable acceleration calibration system

    Science.gov (United States)

    Johnson, Thomas H.

    2011-12-01

    A variable acceleration calibration system that applies loads using gravitational and centripetal acceleration serves as an alternative, efficient and cost effective method for calibrating internal wind tunnel force balances. Two proof-of-concept variable acceleration calibration systems are designed, fabricated and tested. The NASA UT-36 force balance served as the test balance for the calibration experiments. The variable acceleration calibration systems are shown to be capable of performing three component calibration experiments with an approximate applied load error on the order of 1% of the full scale calibration loads. Sources of error are indentified using experimental design methods and a propagation of uncertainty analysis. Three types of uncertainty are indentified for the systems and are attributed to prediction error, calibration error and pure error. Angular velocity uncertainty is shown to be the largest indentified source of prediction error. The calibration uncertainties using a production variable acceleration based system are shown to be potentially equivalent to current methods. The production quality system can be realized using lighter materials and a more precise instrumentation. Further research is needed to account for balance deflection, forcing effects due to vibration, and large tare loads. A gyroscope measurement technique is shown to be capable of resolving the balance deflection angle calculation. Long term research objectives include a demonstration of a six degree of freedom calibration, and a large capacity balance calibration.

  11. 14 CFR 105.45 - Use of tandem parachute systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Use of tandem parachute systems. 105.45 Section 105.45 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... completed a tandem instructor course given by the manufacturer of the tandem parachute system used in...

  12. The KLOE Online Calibration System

    Institute of Scientific and Technical Information of China (English)

    E.Pasqualucci

    2001-01-01

    Based on all the features of the KLOE online software,the online calibration system performs current calibration quality checking in real time and starts automatically new calibration procedures when needed.Acalibration manager process controls the system,implementing the interface to the online system,receiving information from the run control and translating its state transitions to a separate state machine.It acts as a " calibration run controller"and performs failure recovery when requested by a set of process checkers.The core of the system is a multi-threaded OO histogram server that receives histogramming commands by remote processes and operates on local ROOT histograms.A client library and C,fortran and C++ application interface libraries allow the user to connect and define his own histogram or read histograms owned by others using an bool-like interface.Several calibration processes running in parallel in a destributed,multiplatform environment can fill the same histograms,allowing fast external information check.A monitor thread allow remote browsing for visual inspection,Pre-filtered data are read in nonprivileged spy mode from the data acquisition system via the Kloe Integrated Dataflow,privileged spy mode from the data acquisiton system via the Kole Integrated Dataflow.The main characteristics of the system are presented.

  13. Measurement System and Calibration report

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    This Measurement System & Calibration report is describing DTU’s measurement system installed at a specific wind turbine. A major part of the sensors has been installed by others (see [1]) the rest of the sensors have been installed by DTU. The results of the measurements, described in this report...

  14. TANDEM

    Data.gov (United States)

    Federal Laboratory Consortium — The Tandem Van de Graaff facility provides researchers with beams of more than 40 different types of ions - atoms that have been stripped of their electrons. One of...

  15. Tandem robot control system and method for controlling mobile robots in tandem

    Energy Technology Data Exchange (ETDEWEB)

    Hayward, David R. (Albuquerque, NM); Buttz, James H. (Albuquerque, NM); Shirey, David L. (Albuquerque, NM)

    2002-01-01

    A control system for controlling mobile robots provides a way to control mobile robots, connected in tandem with coupling devices, to navigate across difficult terrain or in closed spaces. The mobile robots can be controlled cooperatively as a coupled system in linked mode or controlled individually as separate robots.

  16. Multi-Axis Accelerometer Calibration System

    Science.gov (United States)

    Finley, Tom; Parker, Peter

    2010-01-01

    A low-cost, portable, and simplified system has been developed that is suitable for in-situ calibration and/or evaluation of multi-axis inertial measurement instruments. This system overcomes facility restrictions and maintains or improves the calibration quality for users of accelerometer-based instruments with applications in avionics, experimental wind tunnel research, and force balance calibration applications. The apparatus quickly and easily positions a multi-axis accelerometer system into a precisely known orientation suitable for in-situ quality checks and calibration. In addition, the system incorporates powerful and sophisticated statistical methods, known as response surface methodology and statistical quality control. These methods improve calibration quality, reduce calibration time, and allow for increased calibration frequency, which enables the monitoring of instrument stability over time.

  17. Absolute calibration in vivo measurement systems

    International Nuclear Information System (INIS)

    Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs

  18. Counter-Rotating Tandem Motor Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Kent Perry

    2009-04-30

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger

  19. The calibration system for the GERDA experiment

    International Nuclear Information System (INIS)

    The GERDA experiment uses the neutrinoless double beta decay to probe three fundamental questions in neutrino physics - Are they Dirac or Majorana particles? What is their absolute mass? What is the mass hierarchy of the three generations? In my talk I present the calibration system for the Ge semiconductor diodes enriched in Ge-76. The system is used to set the energy scale and calibrate the pulse shapes which will be used to further reject background events. The lowest possible background is crucial for the whole experiment and therefore the calibration system must not interfere with the data acquisition phase while at the same time operate efficiently during the calibration runs.

  20. DECal: A Spectrophotometric Calibration System For DECam

    CERN Document Server

    Marshall, J L; DePoy, D L; Prochaska, Travis; Allen, Richard; Behm, Tyler W; Martin, Emily C; Veal, Brannon; Villanueva,, Steven; Williams, Patrick; Wise, Jason

    2013-01-01

    DECal is a new calibration system for the CTIO 4 m Blanco telescope. It is currently being installed as part of the Dark Energy Survey and will provide both broadband flat fields and narrowband (about 1 nm bandwidth) spectrophotometric calibration for the new Dark Energy Camera (DECam). Both of these systems share a new Lambertian flat field screen. The broadband flat field system uses LEDs to illuminate each photometric filter. The spectrophotometric calibration system consists of a monochromator-based tunable light source that is projected onto the flat field screen using a custom line-to-spot fiber bundle and an engineered diffuser. Several calibrated photodiodes positioned along the beam monitor the telescope throughput as a function of wavelength. This system will measure the wavelength-dependent instrumental response function of the total telescope+instrument system in the range 300 < lambda < 1100nm. The spectrophotometric calibration will be performed regularly (roughly once per month) to determ...

  1. FY2008 Calibration Systems Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, Bret D.; Myers, Tanya L.; Broocks, Bryan T.

    2009-01-01

    The Calibrations project has been exploring alternative technologies for calibration of passive sensors in the infrared (IR) spectral region. In particular, we have investigated using quantum cascade lasers (QCLs) because these devices offer several advantages over conventional blackbodies such as reductions in size and weight while providing a spectral source in the IR with high output power. These devices can provide a rapid, multi-level radiance scheme to fit any nonlinear behavior as well as a spectral calibration that includes the fore-optics, which is currently not available for on-board calibration systems.

  2. Measurement System and Calibration report

    DEFF Research Database (Denmark)

    Vesth, Allan; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...

  3. Characterization of Tandem systems of commercial ionization chambers for radiation dosimetry (radiotherapy level)

    CERN Document Server

    Galhardo, E P

    1998-01-01

    The use of X rays for radiotherapy purposes is of great importance for Medicine, and it is necessary to control periodically the performance of the ionization chambers and the radiation beams in order to obtain the best results. The verification of the beam characteristics is made by using standard dosimetry procedures which include the determination of the half-value layers and the exposure rates or the absorbed dose rates in air. Several Tandem systems were set up and tested, using commercial ionization chambers in the energy interval from 14 up to 130 KeV at the Instrumentation Calibration Laboratory of IPEN and at other three institutions, in substitution to the routine conventional procedure of determination of half-value layers using absorbers. The obtained results show the usefulness of these Tandem system for the routine dosimetric procedures of radiotherapy X radiation beams.

  4. Systems and methods of eye tracking calibration

    DEFF Research Database (Denmark)

    2014-01-01

    Methods and systems to facilitate eye tracking control calibration are provided. One or more objects are displayed on a display of a device, where the one or more objects are associated with a function unrelated to a calculation of one or more calibration parameters. The one or more calibration...... parameters relate to a calibration of a calculation of gaze information of a user of the device, where the gaze information indicates where the user is looking. While the one or more objects are displayed, eye movement information associated with the user is determined, which indicates eye movement of one...... or more eye features associated with at least one eye of the user. The eye movement information is associated with a first object location of the one or more objects. The one or more calibration parameters are calculated based on the first object location being associated with the eye movement information....

  5. Neutral beam control systems for the Tandem Mirror Experiment

    International Nuclear Information System (INIS)

    The Tandem Mirror Experiment (TMX) is presently developing the technology and approaches which will be used in larger fusion systems. This paper describes some of the designs which were used in creating the control system for the TMX neutral beams. To create a system of controls that would work near these large, rapid switching current sources required a mixture of different technologies: fiberoptic data transmission, printed circuit and wirewrap techniques, etc

  6. The MINOS light-injection calibration system

    International Nuclear Information System (INIS)

    A description is given of the light-injection calibration system that has been developed for the MINOS long-baseline neutrino oscillation experiment. The system is based upon pulsed blue LEDs monitored by PIN photodiodes. It is designed to measure non-linearities in the PMT gain curves, as well as monitoring any drifts in PMT gain, at the 1% level

  7. Is Your System Calibrated? MRI Gradient System Calibration for Pre-Clinical, High-Resolution Imaging

    OpenAIRE

    James O'Callaghan; Jack Wells; Simon Richardson; Holly Holmes; Yichao Yu; Simon Walker-Samuel; Bernard Siow; Lythgoe, Mark F

    2014-01-01

    High-field, pre-clinical MRI systems are widely used to characterise tissue structure and volume in small animals, using high resolution imaging. Both applications rely heavily on the consistent, accurate calibration of imaging gradients, yet such calibrations are typically only performed during maintenance sessions by equipment manufacturers, and potentially with acceptance limits that are inadequate for phenotyping. To overcome this difficulty, we present a protocol for gradient calibration...

  8. ATLAS Tile calorimeter calibration and monitoring systems

    CERN Document Server

    Chomont, Arthur Rene; The ATLAS collaboration

    2016-01-01

    The ATLAS Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of the ATLAS experiment and provides important information for reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. This sampling calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by wavelength shifting fibres to photomultiplier tubes (PMTs), located on the outside of the calorimeter. The readout is segmented into about 5000 cells (longitudinally and transversally), each of them being read out by two PMTs in parallel. To calibrate and monitor the stability and performance of each part of the readout chain during the data taking, a set of calibration systems is used. The TileCal calibration system comprises Cesium radioactive sources, laser and charge injection elements and it allows to monitor and equalize the calorimeter response at each stage of the signal production, from scin...

  9. Polarimetric PALSAR System Model Assessment and Calibration

    Science.gov (United States)

    Touzi, R.; Shimada, M.

    2009-04-01

    Polarimetric PALSAR system parameters are assessed using data sets collected over various calibration sites. The data collected over the Amazonian forest permits validating the zero Faraday rotation hypotheses near the equator. The analysis of the Amazonian forest data and the response of the corner reflectors deployed during the PALSAR acquisitions lead to the conclusion that the antenna is highly isolated (better than -35 dB). Theses results are confirmed using data collected over the Sweden and Ottawa calibration sites. The 5-m height trihedrals deployed in the Sweden calibration site by the Chalmers University of technology permits accurate measurement of antenna parameters, and detection of 2-3 degree Faraday rotation during day acquisition, whereas no Faraday rotation was noted during night acquisition. Small Faraday rotation angles (2-3 degree) have been measured using acquisitions over the DLR Oberpfaffenhofen and the Ottawa calibration sites. The presence of small but still significant Faraday rotation (2-3 degree) induces a CR return at the crosspolarization HV and VH that should not be interpreted as the actual antenna cross-talk. PALSAR antenna is highly isolated (better than -35 dB), and diagonal antenna distortion matrices (with zero cross-talk terms) can be used for accurate calibration of PALSAR polarimetric data.

  10. MULTIPLE ELECTRONIC CONTROL UNITS CALIBRATION SYSTEM BASED ON EXPLICIT CALIBRATION PROTOCOL AND J1939 PROTOCOL

    Institute of Scientific and Technical Information of China (English)

    YANG Shiwei; ZHU Keqing; XU Quankui; YANG Lin; ZHUO Bin

    2008-01-01

    The rising number of electronic control units (ECUs) in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the explicit calibration protocol (XCP) and J1939 communication protocol to satisfy the need of calibrating multiple ECUs simultaneously. The messages in the controller area network (CAN) are defined in the J1939 protocol. Each CAN node can get its own calibration messages and information from other ECUs, and block other messages by qualifying the CAN messages with priority, source or destination address. The data field of the calibration message is designed with the XCP , with CAN acting as the transport layer. The calibration sessions are setup with the event-triggered XCP driver in the master node and the responding XCP driver in the slave nodes. Mirroring calibration variables from ROM to RAM enables the user to calibrate ECUs online. The application example shows that the multi-ECU calibration system can calibrate multiple ECUs simultaneously, and the main program can also accomplish its calculation and send commands to the actuators in time. By the multi-ECU calibration system, the calibration effort and time can be reduced and the variables in ECU can get a better match with the variables of other ECUs.

  11. Computer Generated Hologram System for Wavefront Measurement System Calibration

    Science.gov (United States)

    Olczak, Gene

    2011-01-01

    Computer Generated Holograms (CGHs) have been used for some time to calibrate interferometers that require nulling optics. A typical scenario is the testing of aspheric surfaces with an interferometer placed near the paraxial center of curvature. Existing CGH technology suffers from a reduced capacity to calibrate middle and high spatial frequencies. The root cause of this shortcoming is as follows: the CGH is not placed at an image conjugate of the asphere due to limitations imposed by the geometry of the test and the allowable size of the CGH. This innovation provides a calibration system where the imaging properties in calibration can be made comparable to the test configuration. Thus, if the test is designed to have good imaging properties, then middle and high spatial frequency errors in the test system can be well calibrated. The improved imaging properties are provided by a rudimentary auxiliary optic as part of the calibration system. The auxiliary optic is simple to characterize and align to the CGH. Use of the auxiliary optic also reduces the size of the CGH required for calibration and the density of the lines required for the CGH. The resulting CGH is less expensive than the existing technology and has reduced write error and alignment error sensitivities. This CGH system is suitable for any kind of calibration using an interferometer when high spatial resolution is required. It is especially well suited for tests that include segmented optical components or large apertures.

  12. Calibration experiments of 3He neutron detectors for analyzing neutron emissivity in the hot-ion mode on the GAMMA 10 tandem mirror

    Science.gov (United States)

    Kohagura, J.; Cho, T.; Hirata, M.; Watanabe, H.; Minami, R.; Numakura, T.; Yoshida, M.; Ito, H.; Tatematsu, Y.; Yatsu, K.; Miyoshi, S.; Ogura, K.; Kondoh, T.; Nishitani, T.; Kwon, M.; England, A. C.

    2003-03-01

    Under the international fusion cooperating research, 3He neutron detectors in the GAMMA 10 tandem mirror are calibrated by the use of a 252Cf spontaneous fission neutron source (8.96×104 n/s). The calibration experiments are carried out with a "rail system" placed along the magnetic axis of the GAMMA 10 central-cell region, where hot ions in the plasma experiments with the bulk temperatures of ˜10 keV are produced. As compared to a previous neutron monitoring system with a BF3 detector in GAMMA 10, the present 3He systems are designed with about two orders-of-magnitude higher neutron-counting efficiency for analyzing a neutron emissivity from the plasmas in a single plasma discharge alone. Two 3He systems are installed near the middle and the end of the central cell so as to identify the central-cell hot-ion axial profile. The filling pressure of 3He, the effective length, and the diameter of the detector are designed as 5 bar, 300 mm, and 50 mm, respectively. The detector output spectra are carefully analyzed by the use of a preamplifier, a shaping amplifier, as well as a multichannel analyzer for each 3He detector. In the present article, the neutron-counting data from the two 3He detectors due to the on-axis 252Cf scan are interpreted in terms of the d-2 intensity dependence (d being the distance between the detector and the neutron source) as well as the effects of the central-cell magnetic coils and the other machine structural components.

  13. Variable Acceleration Force Calibration System (VACS)

    Science.gov (United States)

    Rhew, Ray D.; Parker, Peter A.; Johnson, Thomas H.; Landman, Drew

    2014-01-01

    Conventionally, force balances have been calibrated manually, using a complex system of free hanging precision weights, bell cranks, and/or other mechanical components. Conventional methods may provide sufficient accuracy in some instances, but are often quite complex and labor-intensive, requiring three to four man-weeks to complete each full calibration. To ensure accuracy, gravity-based loading is typically utilized. However, this often causes difficulty when applying loads in three simultaneous, orthogonal axes. A complex system of levers, cranks, and cables must be used, introducing increased sources of systematic error, and significantly increasing the time and labor intensity required to complete the calibration. One aspect of the VACS is a method wherein the mass utilized for calibration is held constant, and the acceleration is changed to thereby generate relatively large forces with relatively small test masses. Multiple forces can be applied to a force balance without changing the test mass, and dynamic forces can be applied by rotation or oscillating acceleration. If rotational motion is utilized, a mass is rigidly attached to a force balance, and the mass is exposed to a rotational field. A large force can be applied by utilizing a large rotational velocity. A centrifuge or rotating table can be used to create the rotational field, and fixtures can be utilized to position the force balance. The acceleration may also be linear. For example, a table that moves linearly and accelerates in a sinusoidal manner may also be utilized. The test mass does not have to move in a path that is parallel to the ground, and no re-leveling is therefore required. Balance deflection corrections may be applied passively by monitoring the orientation of the force balance with a three-axis accelerometer package. Deflections are measured during each test run, and adjustments with respect to the true applied load can be made during the post-processing stage. This paper will

  14. The Kinetic Stabilizer: A Route to Simpler Tandem Mirror Systems?

    Energy Technology Data Exchange (ETDEWEB)

    Post, R

    2001-05-30

    This paper discusses a new approach to an MHD stabilizing technique for magnetic fusion systems of the axisymmetric ''open-ended'' variety. The concept is adaptable to tandem-mirror systems and would result in a major simplification of such systems, accompanied by a substantial improvement in their confinement characteristics, The paper first discusses the present impetus to find a simpler and less expensive route to fusion than that offered by the mainline approach, the tokamak. The history of magnetic fusion research shows that closed and open systems exhibit very different confinement characteristics. Closed systems, such as the tokamak, the stellarator, or the reversed-field pinch have cross-field transport that is dominated by plasma turbulence. By contrast, there are examples of open-systems where turbulence, if present at all, was at such low levels that the transport agreed with ''classical'' predictions. The clearest examples are ones in which the field geometry was axiymmetric. However axisymmetric mirror systems are subject to MHD instability. Thus in the years following the famous Ioffe experiment, most open systems have employed asymmetric magnetic fields, with attendant problems of complexity and enhanced cross-field transport. This paper proposes a new means of stabilizing axisymmetric mirror-based systems. The idea, called the ''Kinetic Stabilizer'' has roots in experiments performed with the axisymmetric Gas Dynamic Trap at Novosibirsk. In these experiments, performed in a high collisionality plasma regime, it was shown that the presence of the effluent plasma in the positive-curvature expanding-field region outside the mirrors was effective in stabilizing a high-beta (30 percent) confined plasma against MHD modes. In the plasmas of tandem-mirror systems the density of the effluent plasma is too low to employ this method of stabilization. The Kinetic Stabilizer solves this problem by using

  15. Development of a tiny tandem balloon system for atmospheric observation

    Science.gov (United States)

    Saito, Yoshitaka; Yamada, Kazuhiko; Fujiwara, Masatomo

    2016-07-01

    A tandem balloon system with a combination of a zero-pressure balloon on top and a super-pressure balloon on the bottom has a unique trajectory characteristic, with different flight altitudes between day and night and thus with ascending and descending motions at dawn and dusk, respectively. This characteristic provides a unique opportunity to explore the atmosphere, e.g., the upper tropospheric and lower stratospheric region with cross-tropopause measurements twice a day. We started development of a tiny tandem balloon system using a 10 m^{3} super-pressure balloon and a 100 m^{3} zero-pressure balloon, with a capability of carrying 3 kg of payload. One of the scientific targets is to measure water vapor, cloud particles, and temperature around the tropical tropopause which is the entry point of the stratospheric and mesospheric meridional circulation. For the data transfer, the iridium satellite communication module, SBD9603 is used. In this paper, the current status of the development will be reported.

  16. Mechanical design of the Tandem Mirror Experiment Upgrade vacuum system

    International Nuclear Information System (INIS)

    The Tandem Mirror Experiment Upgrade (TMX Upgrade) vacuum system uses most of the vacuum system from the original TMX and substantially increases its capabilities. The vacuum system provides the main structure for the experimental apparatus, as well as providing and maintaining the vacuum environment. The vacuum vessel provides the structure supporting all magnets, as they are contained inside the vacuum vessel, all of the neutral-beam injectors, and the various diagnostics. The vessel provides the main vacuum enclosure and the various access ports required by the magnet system, injector system, internal vacuum system, and plasma diagnostics. The vacuum environment is created and maintained by two systems, the external vacuum system and the internal vacuum system. The external system consists of mechanical pumps, turbopumps, and cryopumps, and creates a vacuum inside the vessel down to a minimum pressure of 10-6 Torr. The internal vacuum system further reduces the pressure into the 10-8 Torr range and provides the fast pumping required to handle the excess gas from the neutral-beam injector system during a plasma shot. The internal vacuum system consists of titanium sublimators and liquid nitrogen (LN) liners that separate the vacuum vessel into various pumping regions

  17. Mechanical design of the Tandem Mirror Experiment Upgrade vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Lang, D.D.; Calderon, M.O.; Thomas, S.R.; Garner, D.R.

    1981-09-24

    The Tandem Mirror Experiment Upgrade (TMX Upgrade) vacuum system uses most of the vacuum system from the original TMX and substantially increases its capabilities. The vacuum system provides the main structure for the experimental apparatus, as well as providing and maintaining the vacuum environment. The vacuum vessel provides the structure supporting all magnets, as they are contained inside the vacuum vessel, all of the neutral-beam injectors, and the various diagnostics. The vessel provides the main vacuum enclosure and the various access ports required by the magnet system, injector system, internal vacuum system, and plasma diagnostics. The vacuum environment is created and maintained by two systems, the external vacuum system and the internal vacuum system. The external system consists of mechanical pumps, turbopumps, and cryopumps, and creates a vacuum inside the vessel down to a minimum pressure of 10/sup -6/ Torr. The internal vacuum system further reduces the pressure into the 10/sup -8/ Torr range and provides the fast pumping required to handle the excess gas from the neutral-beam injector system during a plasma shot. The internal vacuum system consists of titanium sublimators and liquid nitrogen (LN) liners that separate the vacuum vessel into various pumping regions.

  18. Calibration and Validation of Measurement System

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Riemann, Sven; Knapp, Wilfried

    The report deals with the calibration of the measuring equipment on board the Wave Dragon, Nissum Bredning prototype.......The report deals with the calibration of the measuring equipment on board the Wave Dragon, Nissum Bredning prototype....

  19. Gas box control system for Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    The Tandem Mirror Experiment-Upgrade (TMX-U) uses several methods to feed gas (usually deuterium) at different energies into the plasma region of the machine. One is an arrangement of eight high-speed piezo-electric valves mounted on special manifolds (gas box) that feed cold gas directly to the plasma. This paper describes the electronic valve control and data acquisition portions of the gas box, which are controlled by a desk-top computer. Various flow profiles have been developed and stored in the control computer for ready access by the operator. The system uses two modes of operation, one that exercises and characterizes the valves and one that operates the valves with the rest of the experiment. Both the valve control signals and the pressure transducers data are recorded on the diagnostics computer so that they are available for experiment analysis

  20. Tandem mirror magnet system for the mirror fusion test facility

    International Nuclear Information System (INIS)

    The Tandem Mirror Fusion Test Facility (MFTF-B) will be a large magnetic fusion experimental facility containing 22 supercounducting magnets including solenoids and C-coils. State-of-the-art technology will be used extensively to complete this facility before 1985. Niobium titanium superconductor and stainless steel structural cases will be the principle materials of construction. Cooling will be pool boiling and thermosiphon flow of 4.5 K liquid helium. Combined weight of the magnets will be over 1500 tonnes and the stored energy will be over 1600 MJ. Magnetic field strength in some coils will be more than 8 T. Detail design of the magnet system will begin early 1981. Basic requirements and conceptual design are disclosed in this paper

  1. Tandem mirror magnet system for the mirror fusion test facility

    Energy Technology Data Exchange (ETDEWEB)

    Bulmer, R.H.; Van Sant, J.H.

    1980-10-14

    The Tandem Mirror Fusion Test Facility (MFTF-B) will be a large magnetic fusion experimental facility containing 22 supercounducting magnets including solenoids and C-coils. State-of-the-art technology will be used extensively to complete this facility before 1985. Niobium titanium superconductor and stainless steel structural cases will be the principle materials of construction. Cooling will be pool boiling and thermosiphon flow of 4.5 K liquid helium. Combined weight of the magnets will be over 1500 tonnes and the stored energy will be over 1600 MJ. Magnetic field strength in some coils will be more than 8 T. Detail design of the magnet system will begin early 1981. Basic requirements and conceptual design are disclosed in this paper.

  2. Calibration of the Hydrological Simulation Program Fortran (HSPF) model using automatic calibration and geographical information systems

    Science.gov (United States)

    Al-Abed, N. A.; Whiteley, H. R.

    2002-11-01

    Calibrating a comprehensive, multi-parameter conceptual hydrological model, such as the Hydrological Simulation Program Fortran model, is a major challenge. This paper describes calibration procedures for water-quantity parameters of the HSPF version 10·11 using the automatic-calibration parameter estimator model coupled with a geographical information system (GIS) approach for spatially averaged properties. The study area was the Grand River watershed, located in southern Ontario, Canada, between 79° 30 and 80° 57W longitude and 42° 51 and 44° 31N latitude. The drainage area is 6965 km2. Calibration efforts were directed to those model parameters that produced large changes in model response during sensitivity tests run prior to undertaking calibration. A GIS was used extensively in this study. It was first used in the watershed segmentation process. During calibration, the GIS data were used to establish realistic starting values for the surface and subsurface zone parameters LZSN, UZSN, COVER, and INFILT and physically reasonable ratios of these parameters among watersheds were preserved during calibration with the ratios based on the known properties of the subwatersheds determined using GIS. This calibration procedure produced very satisfactory results; the percentage difference between the simulated and the measured yearly discharge ranged between 4 to 16%, which is classified as good to very good calibration. The average simulated daily discharge for the watershed outlet at Brantford for the years 1981-85 was 67 m3 s-1 and the average measured discharge at Brantford was 70 m3 s-1. The coupling of a GIS with automatice calibration produced a realistic and accurate calibration for the HSPF model with much less effort and subjectivity than would be required for unassisted calibration.

  3. Design and Implementation of A Circuit Board Calibration System

    Directory of Open Access Journals (Sweden)

    Bai Hang

    2016-01-01

    Full Text Available With the development of science and technology, the traditional artificial detection methods cannot meet the requirements of modern equipment testing and calibration. Combined with the actual demand, a kind of circuit boards calibration system are put forward. It can to realize automatic testing and calibration of the circuit boards. Many functions of the calibration system such as automatic testing, self-test and monitoring are summarized. The hardware is introduced which including the industrial computer system, calibration adapter and so on. Then, development platform, the thought of program design and the structure of the software are introduced in detail. The function of automatic calibration to specific circuit boards are realized. Because the system has good commonality and easy to extend to upgrade, the development ideas and experiences can be applied to similar circuit boards automatic testing system.

  4. Calibration method for a central catadioptric-perspective camera system.

    Science.gov (United States)

    He, Bingwei; Chen, Zhipeng; Li, Youfu

    2012-11-01

    A central catadioptric-perspective camera system is widely used nowadays. A critical problem is that current calibration methods cannot determine the extrinsic parameters between the central catadioptric camera and a perspective camera effectively. We present a novel calibration method for a central catadioptric-perspective camera system, in which the central catadioptric camera has a hyperbolic mirror. Two cameras are used to capture images of one calibration pattern at different spatial positions. A virtual camera is constructed at the origin of the central catadioptric camera and faced toward the calibration pattern. The transformation between the virtual camera and the calibration pattern could be computed first and the extrinsic parameters between the central catadioptric camera and the calibration pattern could be obtained. Three-dimensional reconstruction results of the calibration pattern show a high accuracy and validate the feasibility of our method.

  5. Calibration Techniques for Accurate Measurements by Underwater Camera Systems.

    Science.gov (United States)

    Shortis, Mark

    2015-12-07

    Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium. This paper reviews the different approaches to the calibration of underwater camera systems in theoretical and practical terms. The accuracy, reliability, validation and stability of underwater camera system calibration are also discussed. Samples of results from published reports are provided to demonstrate the range of possible accuracies for the measurements produced by underwater camera systems.

  6. Method for Ground-to-Space Laser Calibration System

    Science.gov (United States)

    Lukashin, Constantine (Inventor); Wielicki, Bruce A. (Inventor)

    2014-01-01

    The present invention comprises an approach for calibrating the sensitivity to polarization, optics degradation, spectral and stray light response functions of instruments on orbit. The concept is based on using an accurate ground-based laser system, Ground-to-Space Laser Calibration (GSLC), transmitting laser light to instrument on orbit during nighttime substantially clear-sky conditions. To minimize atmospheric contribution to the calibration uncertainty the calibration cycles should be performed in short time intervals, and all required measurements are designed to be relative. The calibration cycles involve ground operations with laser beam polarization and wavelength changes.

  7. Mammography calibration qualities establishment in a Mo- Mo clinical system

    Science.gov (United States)

    Corrêa, E. L.; dos Santos, L. R.; Vivolo, V.; Potiens, M. P. A.

    2016-07-01

    In this study the mammography calibration qualities were established in a clinical mammography system. The objective is to provide the IPEN instruments calibration laboratory with both mammography calibration methods (using a clinical and an industrial system). The results showed a good behavior of mammography equipment, in terms of kVp, PPV and exposure time. The additional filtration of molybdenum is adequate, air-kerma rates were determined and spectra were obtained.

  8. Is your system calibrated? MRI gradient system calibration for pre-clinical, high-resolution imaging.

    Directory of Open Access Journals (Sweden)

    James O'Callaghan

    Full Text Available High-field, pre-clinical MRI systems are widely used to characterise tissue structure and volume in small animals, using high resolution imaging. Both applications rely heavily on the consistent, accurate calibration of imaging gradients, yet such calibrations are typically only performed during maintenance sessions by equipment manufacturers, and potentially with acceptance limits that are inadequate for phenotyping. To overcome this difficulty, we present a protocol for gradient calibration quality assurance testing, based on a 3D-printed, open source, structural phantom that can be customised to the dimensions of individual scanners and RF coils. In trials on a 9.4 T system, the gradient scaling errors were reduced by an order of magnitude, and displacements of greater than 100 µm, caused by gradient non-linearity, were corrected using a post-processing technique. The step-by-step protocol can be integrated into routine pre-clinical MRI quality assurance to measure and correct for these errors. We suggest that this type of quality assurance is essential for robust pre-clinical MRI experiments that rely on accurate imaging gradients, including small animal phenotyping and diffusion MR.

  9. Calibration of sources for alpha spectroscopy systems

    International Nuclear Information System (INIS)

    This paper describes the calibration methodology for measuring the total alpha activity of plane and thin sources with the Alpha Spectrometer for Silicon Detector in the Nuclear Measures and Dosimetry laboratory at IEAv/CTA. (author)

  10. High Spectral Resolution Lidar: System Calibration

    Science.gov (United States)

    Vivek Vivekanandan, J.; Morley, Bruce; Spuler, Scott; Eloranta, Edwin

    2015-04-01

    One of the unique features of the high spectral resolution lidar (HSRL) is simultaneous measurements of backscatter and extinction of atmosphere. It separates molecular scattering from aerosol and cloud particle backscatter based on their Doppler spectrum width. Scattering from aerosol and cloud particle are referred as Mie scattering. Molecular or Rayleigh scattering is used as a reference for estimating aerosol extinction and backscatter cross-section. Absolute accuracy of the backscattered signals and their separation into Rayleigh and Mie scattering depends on spectral purity of the transmitted signals, accurate measurement of transmit power, and precise performance of filters. Internal calibration is used to characterize optical subsystems Descriptions of high spectral resolution lidar system and its measurement technique can be found in Eloronta (2005) and Hair et al.(2001). Four photon counting detectors are used to measure the backscatter from the combined Rayleigh and molecular scattering (high and low gain), molecular scattering and cross-polarized signal. All of the detectors are sensitive to crosstalk or leakage through the optical filters used to separate the received signals and special data files are used to remove these effects as much as possible. Received signals are normalized with respect to the combined channel response to Mie and Rayleigh scattering. The laser transmit frequency is continually monitored and tuned to the 1109 Iodine absorption line. Aerosol backscatter cross-section is measured by referencing the aerosol return signal to the molecular return signal. Extinction measurements are calculated based on the differences between the expected (theoretical) and actual change in the molecular return. In this paper an overview of calibration of the HSRL is presented. References: Eloranta, E. W., High Spectral Resolution Lidar in Lidar: Range-Resolved Optical Remote Sensing of the Atmosphere, Klaus Weitkamp editor, Springer Series in Optical

  11. Automatic calibration system for VENUS lead glass counters

    International Nuclear Information System (INIS)

    Automatic calibration system for VENUS lead glass counters has been constructed. It consists of a moving table, position sensors, control electronics and a master minicomputer, (micro-11 of DEC). The system has been well operated for six months and one third of VENUS lead glass counters have been calibrated. (author)

  12. Radioxenon detector calibration spike production and delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Foxe, Michael P.; Cameron, Ian M.; Cooper, Matthew W.; Haas, Derek A.; Hayes, James C.; Kriss, Aaron A.; Lidey, Lance S.; Mendez, Jennifer M.; Prinke, Amanda M.; Riedmann, Robin A.

    2016-03-01

    Abstract Beta-Gamma coincidence radioxenon detectors must be calibrated for each of the four-radioxenon isotopes (135Xe, 133Xe, 133mXe, and 131mXe). Without a proper calibration, there is potential for the misidentification of the amount of each isotope detected. It is important to accurately determine the amount of each radioxenon isotope, as the ratios can be used to distinguish between an anthropogenic source and a nuclear explosion. We have developed a xenon calibration system (XeCalS) that produces calibration spikes of known activity and pressure for field calibration of detectors. The activity concentrations of these calibration spikes are measured using a beta-gamma coincidence detector and a high purity germanium (HPGe) detector. We will present the results from the development and commissioning of XeCalS, along with the future plans for a portable spike implementation system.

  13. System and method for calibrating a rotary absolute position sensor

    Science.gov (United States)

    Davis, Donald R. (Inventor); Permenter, Frank Noble (Inventor); Radford, Nicolaus A (Inventor)

    2012-01-01

    A system includes a rotary device, a rotary absolute position (RAP) sensor generating encoded pairs of voltage signals describing positional data of the rotary device, a host machine, and an algorithm. The algorithm calculates calibration parameters usable to determine an absolute position of the rotary device using the encoded pairs, and is adapted for linearly-mapping an ellipse defined by the encoded pairs to thereby calculate the calibration parameters. A method of calibrating the RAP sensor includes measuring the rotary position as encoded pairs of voltage signals, linearly-mapping an ellipse defined by the encoded pairs to thereby calculate the calibration parameters, and calculating an absolute position of the rotary device using the calibration parameters. The calibration parameters include a positive definite matrix (A) and a center point (q) of the ellipse. The voltage signals may include an encoded sine and cosine of a rotary angle of the rotary device.

  14. Geometric calibration for a SPECT system dedicated to breast imaging

    Institute of Scientific and Technical Information of China (English)

    WU Li-Wei; WEI Long; CAO Xue-Xiang; WANG Lu; HUANG Xian-Chao; CHAI Pei; YUN Ming-Kai; ZHANG Yu-Bao; ZHANG Long; SHAN Bao-Ci

    2012-01-01

    Geometric calibration is critical to the accurate SPECT reconstruction.In this paper,a geometric calibration method was developed for a dedicated breast SPECT system with a tilted parallel beam (TPB)orbit.The acquisition geometry of the breast SPECT was firstly characterized.And then its projection model was established based on the acquisition geometry.Finally,the calibration results were obtained using a nonlinear optimization method that fitted the measured projections to the model.Monte Carlo data of the breast SPECT were used to verify the calibration method.Simulation results showed that the geometric parameters with reasonable accuracy could be obtained by the proposed method.

  15. Internal Calibration of HJ-1-C Satellite SAR System

    Directory of Open Access Journals (Sweden)

    Yang Zhen

    2014-06-01

    Full Text Available The HJ-1-C satellite is a Synthetic Aperture Radar (SAR satellite of a small constellation for environmental and disaster monitoring. At present, it is in orbit and working well. The SAR system uses a mesh reflector antenna and centralized power amplifier, and has an internal calibration function in orbit. This study introduces the internal calibration modes and signal paths. The design and realization of the internal calibrator are discussed in detail. Finally, the internal calibration data acquired in orbit are also analyzed.

  16. Manual Calibration System for Daya Bay Reactor Neutrino Experiment

    Institute of Scientific and Technical Information of China (English)

    HUANG; Han-xiong; RUAN; Xi-chao; REN; Jie; LV; Yin-long; FAN; Cheng-jun; CHEN; Yan-nan; WANG; Zhao-hui; ZHOU; Zu-ying; HOU; Long; ZHANG; Jia-wen; ZHANG; Yin-hong; YU; Chao-ju; HE; Wei; ZHOU; Bin

    2012-01-01

    <正>The neutrino mixing angle θ13 with a significance of 7.7 standard deviations has been published by the Daya Bay anti-neutrino experiment collaboration in 2012. To understand the non-uniformity and the energy non-linearity of the anti-neutrino detector (AD), a calibration campaign for the AD1 with the Manual Calibration System (MCS) has been finished. The aim of this calibration plan is to deploy the calibration sources to any positions inside the Inner Acrylic Vessel (IAV), to study detail properties of AD.

  17. Single Vector Calibration System for Multi-Axis Load Cells and Method for Calibrating a Multi-Axis Load Cell

    Science.gov (United States)

    Parker, Peter A. (Inventor)

    2003-01-01

    A single vector calibration system is provided which facilitates the calibration of multi-axis load cells, including wind tunnel force balances. The single vector system provides the capability to calibrate a multi-axis load cell using a single directional load, for example loading solely in the gravitational direction. The system manipulates the load cell in three-dimensional space, while keeping the uni-directional calibration load aligned. The use of a single vector calibration load reduces the set-up time for the multi-axis load combinations needed to generate a complete calibration mathematical model. The system also reduces load application inaccuracies caused by the conventional requirement to generate multiple force vectors. The simplicity of the system reduces calibration time and cost, while simultaneously increasing calibration accuracy.

  18. Omnidirectional vision systems calibration, feature extraction and 3D information

    CERN Document Server

    Puig, Luis

    2013-01-01

    This work focuses on central catadioptric systems, from the early step of calibration to high-level tasks such as 3D information retrieval. The book opens with a thorough introduction to the sphere camera model, along with an analysis of the relation between this model and actual central catadioptric systems. Then, a new approach to calibrate any single-viewpoint catadioptric camera is described.  This is followed by an analysis of existing methods for calibrating central omnivision systems, and a detailed examination of hybrid two-view relations that combine images acquired with uncalibrated

  19. Fast calibration of high-order adaptive optics systems.

    Science.gov (United States)

    Kasper, Markus; Fedrigo, Enrico; Looze, Douglas P; Bonnet, Henri; Ivanescu, Liviu; Oberti, Sylvain

    2004-06-01

    We present a new method of calibrating adaptive optics systems that greatly reduces the required calibration time or, equivalently, improves the signal-to-noise ratio. The method uses an optimized actuation scheme with Hadamard patterns and does not scale with the number of actuators for a given noise level in the wavefront sensor channels. It is therefore highly desirable for high-order systems and/or adaptive secondary systems on a telescope without a Gregorian focal plane. In the latter case, the measurement noise is increased by the effects of the turbulent atmosphere when one is calibrating on a natural guide star. PMID:15191182

  20. Toward an Automatic Calibration of Dual Fluoroscopy Imaging Systems

    Science.gov (United States)

    Al-Durgham, Kaleel; Lichti, Derek; Kuntze, Gregor; Sharma, Gulshan; Ronsky, Janet

    2016-06-01

    High-speed dual fluoroscopy (DF) imaging provides a novel, in-vivo solution to quantify the six-degree-of-freedom skeletal kinematics of humans and animals with sub-millimetre accuracy and high temporal resolution. A rigorous geometric calibration of DF system parameters is essential to ensure precise bony rotation and translation measurements. One way to achieve the system calibration is by performing a bundle adjustment with self-calibration. A first-time bundle adjustment-based system calibration was recently achieved. The system calibration through the bundle adjustment has been shown to be robust, precise, and straightforward. Nevertheless, due to the inherent absence of colour/semantic information in DF images, a significant amount of user input is needed to prepare the image observations for the bundle adjustment. This paper introduces a semi-automated methodology to minimise the amount of user input required to process calibration images and henceforth to facilitate the calibration task. The methodology is optimized for processing images acquired over a custom-made calibration frame with radio-opaque spherical targets. Canny edge detection is used to find distinct structural components of the calibration images. Edge-linking is applied to cluster the edge pixels into unique groups. Principal components analysis is utilized to automatically detect the calibration targets from the groups and to filter out possible outliers. Ellipse fitting is utilized to achieve the spatial measurements as well as to perform quality analysis over the detected targets. Single photo resection is used together with a template matching procedure to establish the image-to-object point correspondence and to simplify target identification. The proposed methodology provided 56,254 identified-targets from 411 images that were used to run a second-time bundle adjustment-based DF system calibration. Compared to a previous fully manual procedure, the proposed methodology has

  1. Accurate and Simple Calibration of DLP Projector Systems

    DEFF Research Database (Denmark)

    Wilm, Jakob; Olesen, Oline Vinter; Larsen, Rasmus

    2014-01-01

    require a camera and involve feature extraction from a known projected pattern. In this work we present a novel calibration technique for DLP Projector systems based on phase shifting profilometry projection onto a printed calibration target. In contrast to most current methods, the one presented here...... does not rely on an initial camera calibration, and so does not carry over the error into projector calibration. A radial interpolation scheme is used to convert features coordinates into projector space, thereby allowing for a very accurate procedure. This allows for highly accurate determination...... of parameters including lens distortion. Our implementation acquires printed planar calibration scenes in less than 1s. This makes our method both fast and convenient. We evaluate our method in terms of reprojection errors and structured light image reconstruction quality....

  2. Optimised limit for polarimetric calibration of fully polarised SAR systems

    OpenAIRE

    Chen, J.; Guo, W; Li, Z.; Liu, W.

    2016-01-01

    The optimised limit for polarimetric calibration of fully polarised synthetic aperture radar systems is derived by establishing an error model as a function of cross-talk, channel imbalance and system noise. Compared with noise equivalent sigma zero, the polarimetric error below the optimised limit is too small to affect the signal of cross-polarised channel. Thus, polarimetric calibration could be relaxed or even ignored in this case. With the backscatter model, optimised limits for cross-ta...

  3. Analysis of 10 systemic pesticide residues in various baby foods using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yang, Angel; Abd El-Aty, A M; Park, Jong-Hyouk; Goudah, Ayman; Rahman, Md Musfiqur; Do, Jung-Ah; Choi, Ok-Ja; Shim, Jae-Han

    2014-06-01

    Ten systemic pesticides, comprising methomyl, thiamethoxam, acetamiprid, carbofuran, fosthiazate, metalaxyl, azoxystrobin, diethofencarb, propiconazole, and difenoconazole, were detected in 13 baby foods (cereals, boiled potatoes, fruit and milk) using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) for sample preparation and liquid chromatography tandem mass spectrometry for analysis. The matrix-matched calibration curves showed good linearity with determination coefficients (R(2) ) >0.992. The limits of detection and quantitation were 0.0015-0.003 and 0.005-0.01 mg/kg, respectively. The mean recoveries of three different concentrations ranged from 69.2 to 127.1% with relative standard deviations pesticide residues. This method is suitable for the identification and quantification of systemic pesticides with matrix-matched standards in various baby foods. PMID:24861738

  4. Systematic Calibration for a Backpacked Spherical Photogrammetry Imaging System

    Science.gov (United States)

    Rau, J. Y.; Su, B. W.; Hsiao, K. W.; Jhan, J. P.

    2016-06-01

    A spherical camera can observe the environment for almost 720 degrees' field of view in one shoot, which is useful for augmented reality, environment documentation, or mobile mapping applications. This paper aims to develop a spherical photogrammetry imaging system for the purpose of 3D measurement through a backpacked mobile mapping system (MMS). The used equipment contains a Ladybug-5 spherical camera, a tactical grade positioning and orientation system (POS), i.e. SPAN-CPT, and an odometer, etc. This research aims to directly apply photogrammetric space intersection technique for 3D mapping from a spherical image stereo-pair. For this purpose, several systematic calibration procedures are required, including lens distortion calibration, relative orientation calibration, boresight calibration for direct georeferencing, and spherical image calibration. The lens distortion is serious on the ladybug-5 camera's original 6 images. Meanwhile, for spherical image mosaicking from these original 6 images, we propose the use of their relative orientation and correct their lens distortion at the same time. However, the constructed spherical image still contains systematic error, which will reduce the 3D measurement accuracy. Later for direct georeferencing purpose, we need to establish a ground control field for boresight/lever-arm calibration. Then, we can apply the calibrated parameters to obtain the exterior orientation parameters (EOPs) of all spherical images. In the end, the 3D positioning accuracy after space intersection will be evaluated, including EOPs obtained by structure from motion method.

  5. Positioning system for single or multi-axis sensitive instrument calibration and calibration system for use therewith

    Science.gov (United States)

    Finley, Tom D. (Inventor); Parker, Peter A. (Inventor)

    2008-01-01

    A positioning and calibration system are provided for use in calibrating a single or multi axis sensitive instrument, such as an inclinometer. The positioning system includes a positioner that defines six planes of tangential contact. A mounting region within the six planes is adapted to have an inclinometer coupled thereto. The positioning system also includes means for defining first and second flat surfaces that are approximately perpendicular to one another with the first surface adapted to be oriented relative to a local or induced reference field of interest to the instrument being calibrated, such as a gravitational vector. The positioner is positioned such that one of its six planes tangentially rests on the first flat surface and another of its six planes tangentially contacts the second flat surface. A calibration system is formed when the positioning system is used with a data collector and processor.

  6. Calibration of robotic drilling systems with a moving rail

    Directory of Open Access Journals (Sweden)

    Tian Wei

    2014-12-01

    Full Text Available Industrial robots are widely used in aircraft assembly systems such as robotic drilling systems. It is necessary to expand a robot’s working range with a moving rail. A method for improving the position accuracy of an automated assembly system with an industrial robot mounted on a moving rail is proposed. A multi-station method is used to control the robot in this study. The robot only works at stations which are certain positions defined on the moving rail. The calibration of the robot system is composed by the calibration of the robot and the calibration of the stations. The calibration of the robot is based on error similarity and inverse distance weighted interpolation. The calibration of the stations is based on a magnetic strip and a magnetic sensor. Validation tests were performed in this study, which showed that the accuracy of the robot system gained significant improvement using the proposed method. The absolute position errors were reduced by about 85% to less than 0.3 mm compared with the maximum nearly 2 mm before calibration.

  7. Calibration of robotic drilling systems with a moving rail

    Institute of Scientific and Technical Information of China (English)

    Tian Wei; Zeng Yuanfan; Zhou Wei; Liao Wenhe

    2014-01-01

    Industrial robots are widely used in aircraft assembly systems such as robotic drilling sys-tems. It is necessary to expand a robot’s working range with a moving rail. A method for improving the position accuracy of an automated assembly system with an industrial robot mounted on a mov-ing rail is proposed. A multi-station method is used to control the robot in this study. The robot only works at stations which are certain positions defined on the moving rail. The calibration of the robot system is composed by the calibration of the robot and the calibration of the stations. The calibration of the robot is based on error similarity and inverse distance weighted interpolation. The calibration of the stations is based on a magnetic strip and a magnetic sensor. Validation tests were performed in this study, which showed that the accuracy of the robot system gained significant improvement using the proposed method. The absolute position errors were reduced by about 85%to less than 0.3 mm compared with the maximum nearly 2 mm before calibration.

  8. A New Method to Calibrate Robot Visual Measurement System

    OpenAIRE

    Yali Wang; Zhenzhong Wei; Mingwei Shao; Guangjun Zhang

    2013-01-01

    This paper presents a new method to calibrate the robot visual measurement system. In the paper, a laser tracker is used to calibrate the robot twist angles. Each axis of the robot is moved to many positions and the positions measured by the laser tracker fit a plane. The normal vectors of the planes are the directions of the axes. According to the definition of the robot kinematics model parameters, the errors of the twist angles can be calculated. The joint angles zero offsets are calibrate...

  9. A portable, automated, inexpensive mass and balance calibration system

    International Nuclear Information System (INIS)

    Reliable mass measurements are essential for a nuclear production facility or process control laboratory. DOE Order 5630.2 requires that traceable standards be used to calibrate and monitor equipment used for nuclear material measurements. To ensure the reliability of mass measurements and to comply with DOE traceability requirements, a portable, automated mass and balance calibration system is used at the Savannah River Plant. Automation is achieved using an EPSON HX-20 notebook computer, which can be operated via RS232C interfacing to electronic balances or function with manual data entry if computer interfacing is not feasible. This economical, comprehensive, user-friendly system has three main functions in a mass measurement control program (MMCP): balance certification, calibration of mass standards, and daily measurement of traceable standards. The balance certification program tests for accuracy, precision, sensitivity, linearity, and cornerloading versus specific requirements. The mass calibration program allows rapid calibration of inexpensive mass standards traceable to certified Class S standards. This MMCP permits daily measurement of traceable standards to monitor the reliability of balances during routine use. The automated system verifies balance calibration, stores results for future use, and provides a printed control chart of the stored data. Another feature of the system permits three different weighing routines that accommodate their need for varying degrees of reliability in routine weighing operations

  10. Laboratory Calibration of a Field Imaging Spectrometer System

    Directory of Open Access Journals (Sweden)

    Qingxi Tong

    2011-02-01

    Full Text Available A new Field Imaging Spectrometer System (FISS based on a cooling area CCD was developed. This paper describes the imaging principle, structural design, and main parameters of the FISS sensor. The FISS was spectrally calibrated with a double grating monochromator to determine the center wavelength and FWHM of each band. Calibration results showed that the spectral range of the FISS system is 437–902 nm, the number of channels is 344 and the spectral resolution of each channel is better than 5 nm. An integrating sphere was used to achieve absolute radiometric calibration of the FISS with less than 5% calibration error for each band. There are 215 channels with signal to noise ratios (SNRs greater than 500 (62.5% of the bands. The results demonstrated that the FISS has achieved high performance that assures the feasibility of its practical use in various fields.

  11. The Calibration System of the HAWC Gamma-Ray Observatory

    CERN Document Server

    Solares, Hugo A Ayala; Hui, C Michelle; Lauer, Robert J; Ren, Zhixiang; Greus, Francisco Salesa; Zhou, Hao

    2015-01-01

    The HAWC collaboration has recently completed the construction of a gamma-ray observatory at an altitude of 4100 meters on the slope of the Sierra Negra volcano in the state of Puebla, Mexico. In order to achieve an optimal angular resolution, energy reconstruction, and cosmic-ray background suppression for the air showers observed by HAWC, it is crucial to obtain good timing and charge calibrations of the photosensors in the detector. The HAWC calibration is based on a laser system which is able to deliver short light pulses to all the tanks in the array. The light intensity can range over 7 orders of magnitude, broad enough to cover all the dynamic range of the PMT readout electronics. In this contribution we will present the HAWC calibration system, together with the methods used to calibrate the detector.

  12. Comparative Analysis of Different LIDAR System Calibration Techniques

    Science.gov (United States)

    Miller, M.; Habib, A.

    2016-06-01

    With light detection and ranging (LiDAR) now being a crucial tool for engineering products and on the fly spatial analysis, it is necessary for the user community to have standardized calibration methods. The three methods in this study were developed and proven by the Digital Photogrammetry Research Group (DPRG) for airborne LiDAR systems and are as follows; Simplified, Quasi-Rigorous, and Rigorous. In lieu of using expensive control surfaces for calibration, these methods compare overlapping LiDAR strips to estimate the systematic errors. These systematic errors are quantified by these methods and include the lever arm biases, boresight biases, range bias and scan angle scale bias. These three methods comprehensively represent all of the possible flight configurations and data availability and this paper will test the limits of the method with the most assumptions, the simplified calibration, by using data that violates the assumptions it's math model is based on and compares the results to the quasi-rigorous and rigorous techniques. The overarching goal is to provide a LiDAR system calibration that does not require raw measurements which can be carried out with minimal control and flight lines to reduce costs. This testing is unique because the terrain used for calibration does not contain gable roofs, all other LiDAR system calibration testing and development has been done with terrain containing features with high geometric integrity such as gable roofs.

  13. Precision Spectrophotometric Calibration System for Dark Energy Instruments

    Energy Technology Data Exchange (ETDEWEB)

    Schubnell, Michael S.

    2015-06-30

    For this research we build a precision calibration system and carried out measurements to demonstrate the precision that can be achieved with a high precision spectrometric calibration system. It was shown that the system is capable of providing a complete spectrophotometric calibration at the sub-pixel level. The calibration system uses a fast, high precision monochromator that can quickly and efficiently scan over an instrument’s entire spectral range with a spectral line width of less than 0.01 nm corresponding to a fraction of a pixel on the CCD. The system was extensively evaluated in the laboratory. Our research showed that a complete spectrophotometric calibration standard for spectroscopic survey instruments such as DESI is possible. The monochromator precision and repeatability to a small fraction of the DESI spectrograph LSF was demonstrated with re-initialization on every scan and thermal drift compensation by locking to multiple external line sources. A projector system that mimics telescope aperture for point source at infinity was demonstrated.

  14. Calibration of the barrel muon drift tubes system in CMS

    Energy Technology Data Exchange (ETDEWEB)

    Maselli, Silvia, E-mail: Silvia.Maselli@to.infn.i [INFN Sez. di Torino, Torino (Italy)

    2010-04-01

    In this report, results on the calibration process of the Drift Tubes (DT) system of the Compact Muon Solenoid experiment are presented. The full commissioning of the calibration procedure has been deployed in year 2008 with the CMS Computing, Software and Analysis challenge (CSA08), which has tested the full work-flow needed for CMS data-taking during the LHC start-up operations. In autumn 2008, the same Calibration work-flow was applied to a high statistics cosmic ray muon data taking period: the Cosmic Run At Four Tesla (CRAFT) period. The accurate measurement of the main calibration conditions corresponding to the Time Pedestals and the Drift Velocity provide the necessary space-time relationship used in the first stage of the muon local reconstruction.

  15. Calibration of the barrel muon drift tubes system in CMS

    International Nuclear Information System (INIS)

    In this report, results on the calibration process of the Drift Tubes (DT) system of the Compact Muon Solenoid experiment are presented. The full commissioning of the calibration procedure has been deployed in year 2008 with the CMS Computing, Software and Analysis challenge (CSA08), which has tested the full work-flow needed for CMS data-taking during the LHC start-up operations. In autumn 2008, the same Calibration work-flow was applied to a high statistics cosmic ray muon data taking period: the Cosmic Run At Four Tesla (CRAFT) period. The accurate measurement of the main calibration conditions corresponding to the Time Pedestals and the Drift Velocity provide the necessary space-time relationship used in the first stage of the muon local reconstruction.

  16. A Statistic-Based Calibration Method for TIADC System

    Directory of Open Access Journals (Sweden)

    Kuojun Yang

    2015-01-01

    Full Text Available Time-interleaved technique is widely used to increase the sampling rate of analog-to-digital converter (ADC. However, the channel mismatches degrade the performance of time-interleaved ADC (TIADC. Therefore, a statistic-based calibration method for TIADC is proposed in this paper. The average value of sampling points is utilized to calculate offset error, and the summation of sampling points is used to calculate gain error. After offset and gain error are obtained, they are calibrated by offset and gain adjustment elements in ADC. Timing skew is calibrated by an iterative method. The product of sampling points of two adjacent subchannels is used as a metric for calibration. The proposed method is employed to calibrate mismatches in a four-channel 5 GS/s TIADC system. Simulation results show that the proposed method can estimate mismatches accurately in a wide frequency range. It is also proved that an accurate estimation can be obtained even if the signal noise ratio (SNR of input signal is 20 dB. Furthermore, the results obtained from a real four-channel 5 GS/s TIADC system demonstrate the effectiveness of the proposed method. We can see that the spectra spurs due to mismatches have been effectively eliminated after calibration.

  17. Stereo Calibration and Rectification for Omnidirectional Multi-camera Systems

    Directory of Open Access Journals (Sweden)

    Yanchang Wang

    2012-10-01

    Full Text Available Stereo vision has been studied for decades as a fundamental problem in the field of computer vision. In recent years, computer vision and image processing with a large field of view, especially using omnidirectional vision and panoramic images, has been receiving increasing attention. An important problem for stereo vision is calibration. Although various kinds of calibration methods for omnidirectional cameras are proposed, most of them are limited to calibrate catadioptric cameras or fish‐eye cameras and cannot be applied directly to multi‐camera systems. In this work, we propose an easy calibration method with closed‐form initialization and iterative optimization for omnidirectional multi‐camera systems. The method only requires image pairs of the 2D target plane in a few different views. A method based on the spherical camera model is also proposed for rectifying omnidirectional stereo pairs. Using real data captured by Ladybug3, we carry out some experiments, including stereo calibration, rectification and 3D reconstruction. Statistical analyses and comparisons of the experimental results are also presented. As the experimental results show, the calibration results are precise and the effect of rectification is promising.

  18. A machine vision system for the calibration of digital thermometers

    Science.gov (United States)

    Vázquez-Fernández, Esteban; Dacal-Nieto, Angel; González-Jorge, Higinio; Martín, Fernando; Formella, Arno; Alvarez-Valado, Victor

    2009-06-01

    Automation is a key point in many industrial tasks such as calibration and metrology. In this context, machine vision has shown to be a useful tool for automation support, especially when there is no other option available. A system for the calibration of portable measurement devices has been developed. The system uses machine vision to obtain the numerical values shown by displays. A new approach based on human perception of digits, which works in parallel with other more classical classifiers, has been created. The results show the benefits of the system in terms of its usability and robustness, obtaining a success rate higher than 99% in display recognition. The system saves time and effort, and offers the possibility of scheduling calibration tasks without excessive attention by the laboratory technicians.

  19. The KamLAND Full-Volume Calibration System

    Energy Technology Data Exchange (ETDEWEB)

    KamLAND Collaboration; Berger, B. E.; Busenitz, J.; Classen, T.; Decowski, M. P.; Dwyer, D. A.; Elor, G.; Frank, A.; Freedman, S. J.; Fujikawa, B. K.; Galloway, M.; Gray, F.; Heeger, K. M.; Hsu, L.; Ichimura, K.; Kadel, R.; Keefer, G.; Lendvai, C.; McKee, D.; O' Donnell, T.; Piepke, A.; Steiner, H. M.; Syversrud, D.; Wallig, J.; Winslow, L. A.; Ebihara, T.; Enomoto, S.; Furuno, K.; Gando, Y.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Nakajima, K.; Nakajima, K.; Nakamura, K.; Owada, K.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Tamae, K.; Yoshida, S.; Kozlov, A.; Murayama, H.; Grant, C.; Leonard, D. S.; Luk, K.-B.; Jillings, C.; Mauger, C.; McKeown, R. D.; Zhang, C.; Lane, C. E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J. G.; Matsuno, S.; Pakvasa, S.; Foster, J.; Horton-Smith, G. A.; Tang, A.; Dazeley, S.; Downum, K. E.; Gratta, G.; Tolich, K.; Bugg, W.; Efremenko, Y.; Kamyshkov, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Piquemal, F.; Ricol, J.-S.

    2009-03-05

    We have successfully built and operated a source deployment system for the KamLAND detector. This system was used to position radioactive sources throughout the delicate 1-kton liquid scintillator volume, while meeting stringent material cleanliness, material compatibility, and safety requirements. The calibration data obtained with this device were used to fully characterize detector position and energy reconstruction biases. As a result, the uncertainty in the size of the detector fiducial volume was reduced by a factor of two. Prior to calibration with this system, the fiducial volume was the largest source of systematic uncertainty in measuring the number of antineutrinos detected by KamLAND. This paper describes the design, operation and performance of this unique calibration system.

  20. The Dark Energy Survey Data Processing and Calibration System

    CERN Document Server

    Mohr, Joseph J; Bertin, Emmanuel; Daues, Gregory E; Desai, Shantanu; Gower, Michelle; Gruendl, Robert; Hanlon, William; Kuropatkin, Nikolay; Lin, Huan; Marriner, John; Petravick, Don; Sevilla, Ignacio; Swanson, Molly; Tomashek, Todd; Tucker, Douglas; Yanny, Brian

    2012-01-01

    The Dark Energy Survey (DES) is a 5000 deg2 grizY survey reaching characteristic photometric depths of 24th magnitude (10 sigma) and enabling accurate photometry and morphology of objects ten times fainter than in SDSS. Preparations for DES have included building a dedicated 3 deg2 CCD camera (DECam), upgrading the existing CTIO Blanco 4m telescope and developing a new high performance computing (HPC) enabled data management system (DESDM). The DESDM system will be used for processing, calibrating and serving the DES data. The total data volumes are high (~2PB), and so considerable effort has gone into designing an automated processing and quality control system. Special purpose image detrending and photometric calibration codes have been developed to meet the data quality requirements, while survey astrometric calibration, coaddition and cataloging rely on new extensions of the AstrOmatic codes which now include tools for PSF modeling, PSF homogenization, PSF corrected model fitting cataloging and joint mode...

  1. Theoretical and experimental investigation on tandem Theoretical and experimental investigation on tandem modulator configurations for Frequency Coded Quantum Key Distribution systems

    CERN Document Server

    Mora, J; Amaya, W; Garcia-Munoz, V; Capmany, J

    2009-01-01

    We have theoretically and experimentally address the possible tandem electro-optical modulator configurations that can be employed to implement Frequency Coded Quantum Key Distribution systems (FC-QKD). A closed and general formulation of the end to end field propagation in a dispersion compensated FC-QKD optical fiber system under the low modulation index regime is presented which accounts for all the possible tandem combinations. The properties and the parameter selection of the modulators to achieve each one are summarized. We also address which protocol (B92, BB84 or either) is feasible to be implemented with each configuration. The results confirm those reported for the configurations previously reported in the literature and, at the same time, show the existence of four novel tandem modulator configurations that can also be employed. We have also provided experimental evidence of the successful operation of the novel configurations that confirm the behavior predicted by the theoretical results.

  2. A harvester based calibration system for cotton yield monitors

    Science.gov (United States)

    The objective of this work was to develop a system for measuring seed cotton weight on a cotton harvester to facilitate on-farm research efforts and provide information for use in semi-real-time calibration of yield monitors. The system tested in 2014 was improved from the original design developed...

  3. Peristaltic pump-based low range pressure sensor calibration system

    Science.gov (United States)

    Vinayakumar, K. B.; Naveen Kumar, G.; Nayak, M. M.; Dinesh, N. S.; Rajanna, K.

    2015-11-01

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.

  4. Peristaltic pump-based low range pressure sensor calibration system

    International Nuclear Information System (INIS)

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory

  5. Peristaltic pump-based low range pressure sensor calibration system.

    Science.gov (United States)

    Vinayakumar, K B; Naveen Kumar, G; Nayak, M M; Dinesh, N S; Rajanna, K

    2015-11-01

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory. PMID:26628178

  6. Peristaltic pump-based low range pressure sensor calibration system

    Energy Technology Data Exchange (ETDEWEB)

    Vinayakumar, K. B. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 5600012 (India); Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 5600012 (India); Naveen Kumar, G.; Rajanna, K., E-mail: kraj@isu.iisc.ernet.in, E-mail: krajanna2011@gmail.com [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 5600012 (India); Nayak, M. M. [Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 5600012 (India); Dinesh, N. S. [Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 5600012 (India)

    2015-11-15

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.

  7. Peristaltic pump-based low range pressure sensor calibration system.

    Science.gov (United States)

    Vinayakumar, K B; Naveen Kumar, G; Nayak, M M; Dinesh, N S; Rajanna, K

    2015-11-01

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.

  8. Calibration of Frequency Data Collection Systems Using Shortwave Radio Signals

    Science.gov (United States)

    Estler, Ron

    2000-09-01

    The atomic-clock-derived audio tones broadcast on the National Institute of Standards and Technology (NIST) shortwave station WWV are used to calibrate computer frequency data collection systems via Fast Fourier Transforms (FFT). Once calibrated, the data collection system can be used to accurately determine the audio signals used in several instructional physical chemistry laboratory experiments. This method can be applied to virtually any hardware-software configuration that allows adjustment of the apparent time scale (digitizing rate) of the recorded audio file.

  9. Calibration methods for ECE systems with microwave sources

    International Nuclear Information System (INIS)

    The authors investigated the feasibility of two methods for calibration of electron cyclotron emission (ECE) systems, both based on the use of a microwave source. In the first method -called the Antenna Pattern Integration (API) method - the microwave source is scanned in space, so as to simulate a large - area - blackbody -source. In the second method -called the Untuned Cavity (UC) method -an untuned cavity, fed by the microwave source, is used to simulate a blackbody. For both methods, the hardware required to perform partly automated calibrations was developed. The microwave based methods were compared with a large area blackbody calibration on two different ECE systems, a Michelson interferometer and a grating polychromator. The API method was found to be more successful than the UC method. (author)

  10. Flexible Calibration Method for 3D Laser Scanner System

    Institute of Scientific and Technical Information of China (English)

    杨中东; 王鹏; 李晓慧; 孙长库

    2014-01-01

    In this paper, a flexible high-precision calibration method suitable for industrial field was proposed. The complexity of the coordinate transformation was simplified by choosing the camera coordinate system as the unified reference coordinate system. A flexible planar calibration pattern was introduced to the calibration process, which can be arbitrarily placed and from which the known feature points can be extracted to construct other unknown feature points. With the known intrinsic parameters, the laser projector plane equation was fitted by the multi-noncollinear points, which were acquired through the principle of triangulation and the projective invariance of cross ratio. With this method, the strict alignment and multiple times of coordinate transformation can be avoided. Experimental results showed that the arithmetic mean of the root mean square (RMS) error of distance was 0.000 7 mm.

  11. Improving Photometric Calibration of Meteor Video Camera Systems

    Science.gov (United States)

    Ehlert, Steven; Kingery, Aaron; Cooke, William

    2016-01-01

    Current optical observations of meteors are commonly limited by systematic uncertainties in photometric calibration at the level of approximately 0.5 mag or higher. Future improvements to meteor ablation models, luminous efficiency models, or emission spectra will hinge on new camera systems and techniques that significantly reduce calibration uncertainties and can reliably perform absolute photometric measurements of meteors. In this talk we discuss the algorithms and tests that NASA's Meteoroid Environment Office (MEO) has developed to better calibrate photometric measurements for the existing All-Sky and Wide-Field video camera networks as well as for a newly deployed four-camera system for measuring meteor colors in Johnson-Cousins BV RI filters. In particular we will emphasize how the MEO has been able to address two long-standing concerns with the traditional procedure, discussed in more detail below.

  12. Calibration technology in application of robot-laser scanning system

    Science.gov (United States)

    Ren, YongJie; Yin, ShiBin; Zhu, JiGui

    2012-11-01

    A system composed of laser sensor and 6-DOF industrial robot is proposed to obtain complete three-dimensional (3-D) information of the object surface. Suitable for the different combining ways of laser sensor and robot, a new method to calibrate the position and pose between sensor and robot is presented. By using a standard sphere with known radius as a reference tool, the rotation and translation matrices between the laser sensor and robot are computed, respectively in two steps, so that many unstable factors introduced in conventional optimization methods can be avoided. The experimental results show that the accuracy of the proposed calibration method can be achieved up to 0.062 mm. The calibration method is also implemented into the automated robot scanning system to reconstruct a car door panel.

  13. Adaptive Color Calibration Based One-Shot Structured Light System

    Directory of Open Access Journals (Sweden)

    Jie Yuan

    2012-08-01

    Full Text Available In one-shot color structured light systems, the color of stripe patterns are typically distorted with respect to color crosstalk, ambient light and the albedo of the scanned objects, leading to mismatch in the correspondence of color stripes between the projected and captured images. In this paper, an adaptive color calibration and Discrete Trend Transform algorithm are presented to achieve high-resolution 3D reconstructions. The adaptive color calibration, according to the relative albedo in RGB channels, can improve the accuracy of labeling stripe by alleviating the effect of albedo and ambient light while decoding the color. Furthermore, the Discrete Trend Transform in the M channel makes the color calibration an effective method for detecting weak stripes due to the uneven surfaces or reflectance characteristics of the scanned objects. With this approach, the presented system is suitable for scanning moving objects and generating high-resolution 3D reconstructions without the need of dark laboratory environments.

  14. The ALICE Silicon Pixel Detector Control and Calibration Systems

    CERN Document Server

    Calì, Ivan Amos; Manzari, Vito; Stefanini, Giorgio

    2008-01-01

    The work presented in this thesis was carried out in the Silicon Pixel Detector (SPD) group of the ALICE experiment at the Large Hadron Collider (LHC). The SPD is the innermost part (two cylindrical layers of silicon pixel detec- tors) of the ALICE Inner Tracking System (ITS). During the last three years I have been strongly involved in the SPD hardware and software development, construction and commissioning. This thesis is focused on the design, development and commissioning of the SPD Control and Calibration Systems. I started this project from scratch. After a prototyping phase now a stable version of the control and calibration systems is operative. These systems allowed the detector sectors and half-barrels test, integration and commissioning as well as the SPD commissioning in the experiment. The integration of the systems with the ALICE Experiment Control System (ECS), DAQ and Trigger system has been accomplished and the SPD participated in the experimental December 2007 commissioning run. The complex...

  15. Simulation of tandem hydrofoils by finite volume method with moving grid system; Henkei koshi wo tsukatta yugen taisekiho ni yoru tandem suichuyoku no simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kawashima, H. [Ship Research Inst., Tokyo (Japan); Miyata, H. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1996-12-31

    With an objective to clarify possibility of application of time-advancing calculated fluid dynamic (CFD) simulation by using a finite volume method with moving grid system, a simulation was performed on motion of a ship with hydrofoils including the control system therein. The simulation consists of a method that couples a moving grid system technology, an equation of motion, and the control system. Complex interactions between wings and with free surface may be considered automatically by directly deriving fluid force from a flow field by using the CFD. In addition, two-dimensional flows around tandem hydrofoils were calculated to solve the motion problem within a vertical plane. As a result, the following results were obtained: a finite volume method using a dynamic moving grid system method was applied to problems in non-steady tandem hydrofoils to show its usefulness; a method that couples the CFD with the equation of motion was applied to the control problems in the tandem hydrofoils to show possibility of a new technology for simulating motions; and a simulation that considers such wing interference as wave creation, discharged vortices, and associated flows was shown useful to understand characteristics of the tandem hydrofoils. 13 refs., 14 figs.

  16. Automated system for the calibration of magnetometers

    DEFF Research Database (Denmark)

    Petrucha, Vojtech; Kaspar, Petr; Ripka, Pavel;

    2009-01-01

    one example. The new platform can also be used to evaluate the parameters of the compass in all possible variations in azimuth, pitch, and roll. The system is based on piezoelectric motors, which are placed on a platform made of aluminum, brass, plastic, and glass. Position sensing is accomplished...

  17. On the efficiency calibration of a drum waste assay system

    CERN Document Server

    Dinescu, L; Cazan, I L; Macrin, R; Caragheorgheopol, G; Rotarescu, G

    2002-01-01

    The efficiency calibration of a gamma spectroscopy waste assay system, constructed by IFIN-HH, was performed. The calibration technique was based on the assumption of a uniform distribution of the source activity in the drum and also a uniform sample matrix. A collimated detector (HPGe--20% relative efficiency) placed at 30 cm from the drum was used. The detection limit for sup 1 sup 3 sup 7 Cs and sup 6 sup 0 Co is approximately 45 Bq/kg for a sample of about 400 kg and a counting time of 10 min. A total measurement uncertainty of -70% to +40% was estimated.

  18. Numerical Analysis of a Radiant Heat Flux Calibration System

    Science.gov (United States)

    Jiang, Shanjuan; Horn, Thomas J.; Dhir, V. K.

    1998-01-01

    A radiant heat flux gage calibration system exists in the Flight Loads Laboratory at NASA's Dryden Flight Research Center. This calibration system must be well understood if the heat flux gages calibrated in it are to provide useful data during radiant heating ground tests or flight tests of high speed aerospace vehicles. A part of the calibration system characterization process is to develop a numerical model of the flat plate heater element and heat flux gage, which will help identify errors due to convection, heater element erosion, and other factors. A 2-dimensional mathematical model of the gage-plate system has been developed to simulate the combined problem involving convection, radiation and mass loss by chemical reaction. A fourth order finite difference scheme is used to solve the steady state governing equations and determine the temperature distribution in the gage and plate, incident heat flux on the gage face, and flat plate erosion. Initial gage heat flux predictions from the model are found to be within 17% of experimental results.

  19. Calibration of a Plastic Classification System with the Ccw Model

    International Nuclear Information System (INIS)

    This document describes the calibration of a plastic Classification system with the Ccw model (Classification by Quantum's built with Wavelet Coefficients). The method is applied to spectra of plastics usually present in domestic wastes. Obtained results are showed. (Author) 16 refs

  20. Seismic margins and calibration of piping systems

    Energy Technology Data Exchange (ETDEWEB)

    Shieh, L.C.; Tsai, N.C.; Yang, M.S.; Wong, W.L.

    1985-01-01

    The Seismic Safety Margins Research Program (SSMRP) is a US Nuclear Regulatory Commission-funded, multiyear program conducted by Lawrence Livermore National Laboratory (LLNL). Its objective is to develop a complete, fully coupled analysis procedure for estimating the risk of earthquake-induced radioactive release from a commercial nuclear power plant and to determine major contributors to the state-of-the-art seismic and systems analysis process and explicitly includes the uncertainties in such a process. The results will be used to improve seismic licensing requirements for nuclear power plants. In Phase I of SSMRP, the overall seismic risk assessment methodology was developed and assembled. The application of this methodology to the seismic PRA (Probabilistic Risk Assessment) at the Zion Nuclear Power Plant has been documented. This report documents the method deriving response factors. The response factors, which relate design calculated responses to best estimate values, were used in the seismic response determination of piping systems for a simplified seismic probablistic risk assessment. 13 references, 31 figures, 25 tables.

  1. Online Sensor Calibration Assessment in Nuclear Power Systems

    International Nuclear Information System (INIS)

    Safe, efficient, and economic operation of nuclear systems (nuclear power plants, fuel fabrication and storage, used fuel processing, etc.) relies on transmission of accurate and reliable measurements. During operation, sensors degrade due to age, environmental exposure, and maintenance interventions. Sensor degradation can affect the measured and transmitted signals, including sensor failure, signal drift, sensor response time, etc. Currently, periodic sensor recalibration is performed to avoid these problems. Sensor recalibration activities include both calibration assessment and adjustment (if necessary). In nuclear power plants, periodic recalibration of safety-related sensors is required by the plant technical specifications. Recalibration typically occurs during refueling outages (about every 18 to 24 months). Non-safety-related sensors also undergo recalibration, though not as frequently. However, this approach to maintaining sensor calibration and performance is time-consuming and expensive, leading to unnecessary maintenance, increased radiation exposure to maintenance personnel, and potential damage to sensors. Online monitoring (OLM) of sensor performance is a non-invasive approach to assess instrument calibration. OLM can mitigate many of the limitations of the current periodic recalibration practice by providing more frequent assessment of calibration and identifying those sensors that are operating outside of calibration tolerance limits without removing sensors or interrupting operation. This can support extended operating intervals for unfaulted sensors and target recalibration efforts to only degraded sensors

  2. Automatic Calibration and Reconstruction for Active Vision Systems

    CERN Document Server

    Zhang, Beiwei

    2012-01-01

    In this book, the design of two new planar patterns for camera calibration of intrinsic parameters is addressed and a line-based method for distortion correction is suggested. The dynamic calibration of structured light systems, which consist of a camera and a projector is also treated. Also, the 3D Euclidean reconstruction by using the image-to-world transformation is investigated. Lastly, linear calibration algorithms for the catadioptric camera are considered, and the homographic matrix and fundamental matrix are extensively studied. In these methods, analytic solutions are provided for the computational efficiency and redundancy in the data can be easily incorporated to improve reliability of the estimations. This volume will therefore prove valuable and practical tool for researchers and practioners working in image processing and computer vision and related subjects.

  3. The Detector Calibration System for the CUORE cryogenic bolometer array

    CERN Document Server

    Cushman, J S; Davis, C J; Ejzak, L; Lenz, D; Lim, K E; Heeger, K M; Maruyama, R H; Nucciotti, A; Sangiorgio, S; Wise, T

    2016-01-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is a ton-scale cryogenic experiment designed to search for neutrinoless double-beta decay of $^{130}$Te and other rare events. The CUORE detector consists of 988 TeO$_2$ bolometers operated underground at 10~mK in a dilution refrigerator at the Laboratori Nazionali del Gran Sasso. Candidate events are identified through a precise measurement of their energy. The absolute energy response of the detectors is established by the regular calibration of each individual bolometer using gamma sources. The close-packed configuration of the CUORE bolometer array combined with the extensive shielding surrounding the detectors requires the placement of calibration sources within the array itself. The CUORE Detector Calibration System is designed to insert radioactive sources into and remove them from the cryostat while respecting the stringent heat load, radiopurity, and operational requirements of the experiment. This paper describes the design, commissioning...

  4. The performance of the CHEOPS on-ground calibration system

    Science.gov (United States)

    Chazelas, B.; Wildi, F. P.; Sarajlic, M.; Sordet, M.; Deline, A.

    2016-07-01

    The CHEOPS space mission will measure photometric transits of exo-planets with a precision of 20 ppm in 6 hours of integration time on a 9th magnitude star. This corresponds to a signal-to-noise ratio of 5 for a transit of an Earth-sized planet orbiting a solar-sized star. Achieving the precision goal requires precise on-ground calibration of the payload to remove its signature from the raw data while in flight. A sophisticated calibration system will inject a stimulus beam in the payload and measure its response to the variation of electrical and environmental parameters. These variations will be compiled in a correction model. At the very end of the testing phase, the CHEOPS photometric performance will be assessed on an artificial star, applying the correction model This paper addresses some original details of the CHEOPS calibration bench and its performance as measured in the lab.

  5. A Technique for Binocular Stereo Vision System Calibration by the Nonlinear Optimization and Calibration Points with Accurate Coordinates

    International Nuclear Information System (INIS)

    With the increasing need for higher accuracy measurement in computer vision, the precision of camera calibration is a more important factor. The objective of stereo camera calibration is to estimate the intrinsic and extrinsic parameters of each camera. We presented a high-accurate technique to calibrate binocular stereo vision system having been mounted the locations and attitudes, which was realized by combining nonlinear optimization method with accurate calibration points. The calibration points with accurate coordinates, were formed by an infrared LED moved with three-dimensional coordinate measurement machine, which can ensure indeterminacy of measurement is 1/30000. By using bilinear interpolation square-gray weighted centroid location algorithm, the imaging centers of the calibration points can be accurately determined. The accuracy of the calibration is measured in terms of the accuracy in the reconstructing calibration points through triangulation, the mean distance between reconstructing point and given calibration point is 0.039mm. The technique can satisfy the goals of measurement and camera accurate calibration

  6. The Habitable-zone Planet Finder Calibration System

    CERN Document Server

    Halverson, Samuel; Ramsey, Lawrence; Terrien, Ryan; Roy, Arpita; Schwab, Christian; Bender, Chad; Hearty, Fred; Levi, Eric; Osterman, Steve; Ycas, Gabe; Diddams, Scott

    2014-01-01

    We present the design concept of the wavelength calibration system for the Habitable-zone Planet Finder instrument (HPF), a precision radial velocity (RV) spectrograph designed to detect terrestrial-mass planets around M-dwarfs. HPF is a stabilized, fiber-fed, R$\\sim$50,000 spectrograph operating in the near-infrared (NIR) z/Y/J bands from 0.84 to 1.3 microns. For HPF to achieve 1 m s$^{-1}$ or better measurement precision, a unique calibration system, stable to several times better precision, will be needed to accurately remove instrumental effects at an unprecedented level in the NIR. The primary wavelength calibration source is a laser frequency comb (LFC), currently in development at NIST Boulder, discussed separately in these proceedings. The LFC will be supplemented by a stabilized single-mode fiber Fabry-Perot interferometer reference source and Uranium-Neon lamp. The HPF calibration system will combine several other new technologies developed by the Penn State Optical-Infrared instrumentation group to...

  7. Novel calibration system with sparse wires for CMB polarization receivers

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, O.; /KEK, Tsukuba /Chicago U., KICP; Nguyen, H.; /Fermilab; Bischoff, C.; /Chicago U., KICP /Harvard-Smithsonian Ctr. Astrophys.; Brizius, A.; Buder, I.; Kusaka, A. /Chicago U., KICP

    2011-07-01

    B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature ({approx}10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.

  8. An accurate continuous calibration system for high voltage current transformer

    International Nuclear Information System (INIS)

    A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.

  9. Compton Backscattering for the Calibration of KEDR Tagging System

    CERN Document Server

    Kaminskiy, V V; Zhilich, V N

    2014-01-01

    KEDR detector has the tagging system (TS) to study the gamma-gamma processes. To determine the two-photon invariant mass, the energies of the scattered at small angles electrons and positrons are measured by the magnetic spectrometer embedded into the lattice of the VEPP--4M collider. The energy resolution (scattered electron/positron energy resolution divided by the beam energy) of this spectrometer varies from 0.6% to 0.03% depending on the electron/positron energy. The Compton backscattering of laser radiation on the electron/positron beam is used for the accurate energy scale and resolution calibration of the tagging system. The report covers the design, recent results and current status of the KEDR TS calibration system.

  10. Compton backscattering for the calibration of KEDR tagging system

    Science.gov (United States)

    Kaminskiy, V. V.; Muchnoi, N. Yu; Zhilich, V. N.

    2014-08-01

    KEDR detector has the tagging system (TS) to study the gamma-gamma processes. To determine the two-photon invariant mass, the energies of the scattered at small angles electrons and positrons are measured by the magnetic spectrometer embedded into the lattice of the VEPP-4M collider. The energy resolution (scattered electron/positron energy resolution divided by the beam energy) of this spectrometer varies from 0.6% to 0.03% depending on the electron/positron energy. The Compton backscattering of laser radiation on the electron/positron beam is used for the accurate energy scale and resolution calibration of the tagging system. The report covers the design, recent results and current status of the KEDR TS calibration system.

  11. Calibration procedure of measuring system for vehicle wheel load estimation

    Science.gov (United States)

    Kluziewicz, M.; Maniowski, M.

    2016-09-01

    The calibration procedure of wheel load measuring system is presented. Designed method allows estimation of selected wheel load components while the vehicle is in motion. Mentioned system is developed to determine friction forces between tire and road surface, basing on measured internal reaction forces in wheel suspension mechanism. Three strain gauge bridges and three-component piezoelectric load cell are responsible for internal force measurement in suspension components, two wire sensors are measuring displacements. External load is calculated via kinematic model of suspension mechanism implemented in Matlab environment. In the described calibration procedure, internal reactions are measured on a test stand while the system is loaded by a force of known direction and value.

  12. X-ray cone beam CT system calibration

    Science.gov (United States)

    Sire, Pascal; Rizo, Philippe; Martin, M.

    1993-12-01

    Recently x-ray cone beam computed tomography (CT) has become of interest for nondestructive testing (NDT) of advanced materials. Such a technique takes advantage of the cone beam geometry, to reduce the acquisition time and increase the resolution. Performances of CT systems rely mainly on geometric precision and measurement quality. Inaccurate geometry or incorrect data produce artifacts and blurring which limit the spatial resolution. A precise geometric calibration procedure is required and some corrections must be applied to the raw attenuation data in order to obtain accurate measurements. An x-ray cone beam CT system has been developed at the LETI. This machine was designed to control small parts limited to a few centimeters, with a high spatial resolution close to 30 microns. This paper introduces the machine setup and describes the calibration computing resources involved in the system. Then, we discuss the performances on experimental data.

  13. Measuring Systems for Thermometer Calibration in Low-Temperature Range

    Science.gov (United States)

    Szmyrka-Grzebyk, A.; Lipiński, L.; Manuszkiewicz, H.; Kowal, A.; Grykałowska, A.; Jancewicz, D.

    2011-12-01

    The national temperature standard for the low-temperature range between 13.8033 K and 273.16 K has been established in Poland at the Institute of Low Temperature and Structure Research (INTiBS). The standard consists of sealed cells for realization of six fixed points of the International Temperature Scale of 1990 (ITS-90) in the low-temperature range, an adiabatic cryostat and Isotech water and mercury triple-point baths, capsule standard resistance thermometers (CSPRT), and AC and DC bridges with standard resistors for thermometers resistance measurements. INTiBS calibrates CSPRTs at the low-temperature fixed points with uncertainties less than 1 mK. In lower temperature range—between 2.5 K and about 25 K — rhodium-iron (RhFe) resistance thermometers are calibrated by comparison with a standard which participated in the EURAMET.T-K1.1 comparison. INTiBS offers a calibration service for industrial platinum resistance thermometers and for digital thermometers between 77 K and 273 K. These types of thermometers may be calibrated at INTiBS also in a higher temperature range up to 550°C. The Laboratory of Temperature Standard at INTiBS acquired an accreditation from the Polish Centre for Accreditation. A management system according to EN ISO/IEC 17025:2005 was established at the Laboratory and presented on EURAMET QSM Forum.

  14. Guidelines for the Calibration of Routine Dosimetry Systems for use in Radiation Processing

    DEFF Research Database (Denmark)

    Sharpe, Peter; Miller, Arne

    A set of guidelines has been developed to assist in the calibration of routine dosimetry systems for use in industrial radiation processing plants. Topics covered include the calibration of equipment, the performance of calibration irradiations and the derivation of mathematical functions...... to represent the calibration. Guidance is also given on methods for the estimation of uncertainty....

  15. Calibration of SQUID vector magnetometers in full tensor gradiometry systems

    Science.gov (United States)

    Schiffler, M.; Queitsch, M.; Stolz, R.; Chwala, A.; Krech, W.; Meyer, H.-G.; Kukowski, N.

    2014-08-01

    Measurement of magnetic vector or tensor quantities, namely of field or field gradient, delivers more details of the underlying geological setting in geomagnetic prospection than a scalar measurement of a single component or of the scalar total magnetic intensity. Currently, highest measurement resolutions are achievable with superconducting quantum interference device (SQUID)-based systems. Due to technological limitations, it is necessary to suppress the parasitic magnetic field response from the SQUID gradiometer signals, which are a superposition of one tensor component and all three orthogonal magnetic field components. This in turn requires an accurate estimation of the local magnetic field. Such a measurement can itself be achieved via three additional orthogonal SQUID reference magnetometers. It is the calibration of such a SQUID reference vector magnetometer system that is the subject of this paper. A number of vector magnetometer calibration methods are described in the literature. We present two methods that we have implemented and compared, for their suitability of rapid data processing and integration into a full tensor magnetic gradiometry, SQUID-based, system. We conclude that the calibration routines must necessarily model fabrication misalignments, field offset and scale factors, and include comparison with a reference magnetic field. In order to enable fast processing on site, the software must be able to function as a stand-alone toolbox.

  16. Development of a Calibration Strip for Immunochromatographic Assay Detection Systems.

    Science.gov (United States)

    Gao, Yue-Ming; Wei, Jian-Chong; Mak, Peng-Un; Vai, Mang-I; Du, Min; Pun, Sio-Hang

    2016-01-01

    With many benefits and applications, immunochromatographic (ICG) assay detection systems have been reported on a great deal. However, the existing research mainly focuses on increasing the dynamic detection range or application fields. Calibration of the detection system, which has a great influence on the detection accuracy, has not been addressed properly. In this context, this work develops a calibration strip for ICG assay photoelectric detection systems. An image of the test strip is captured by an image acquisition device, followed by performing a fuzzy c-means (FCM) clustering algorithm and maximin-distance algorithm for image segmentation. Additionally, experiments are conducted to find the best characteristic quantity. By analyzing the linear coefficient, an average value of hue (H) at 14 min is chosen as the characteristic quantity and the empirical formula between H and optical density (OD) value is established. Therefore, H, saturation (S), and value (V) are calculated by a number of selected OD values. Then, H, S, and V values are transferred to the RGB color space and a high-resolution printer is used to print the strip images on cellulose nitrate membranes. Finally, verification of the printed calibration strips is conducted by analyzing the linear correlation between OD and the spectral reflectance, which shows a good linear correlation (R² = 98.78%). PMID:27367694

  17. Panoptes: Calibration of a dosimetry system for eye brachytherapy

    International Nuclear Information System (INIS)

    Intraocular cancer is a serious threat to the lives of those that suffer from it. Dosimetry for eye brachytherapy presents a significant challenge due to the inherently steep dose gradients that are needed to treat such small tumours in close proximity to sensitive normal structures. This issue is addressed by providing much needed quality assurance to eye brachytherapy, a novel volumetric dosimetry system, called PANOPTES was developed. This study focuses on the preliminary characterisation and calibration of the system. Using ion beam facilities, the custom, pixelated silicon detector of PANOPTES was shown to have good charge collection uniformity and a well defined sensitive volume. Flat-field calibration was conducted on the device using a 250 kVp orthovoltage beam. Finally, the detector and phantom were simulated with Monte Carlo in Geant4, to create water equivalent dose correction factors for each pixel across a range of angles. - Highlights: • Volumetric detector system produced for plaque brachytherapy. • Orthovoltage, flat-field calibration performed for detector pixels. • Monte Carlo simulation showed mostly little angular deviation across all angles. • Ion beam induced charge collection showed pixels uniform and fully depleted

  18. The development and application of a multiplex short tandem repeat (STR) system for identifying subspecies, individuals and sex in tigers.

    Science.gov (United States)

    Zou, Zheng-Ting; Uphyrkina, Olga V; Fomenko, Pavel; Luo, Shu-Jin

    2015-07-01

    Poaching and trans-boundary trafficking of tigers and body parts are threatening the world's last remaining wild tigers. Development of an efficient molecular genetic assay for tracing the origins of confiscated specimens will assist in law enforcement and wildlife forensics for this iconic flagship species. We developed a multiplex genotyping system "tigrisPlex" to simultaneously assess 22 short tandem repeat (STR, or microsatellite) loci and a gender-identifying SRY gene, all amplified in 4 reactions using as little as 1 ng of template DNA. With DNA samples used for between-run calibration, the system generates STR genotypes that are directly compatible with voucher tiger subspecies genetic profiles, hence making it possible to identify subspecies via bi-parentally inherited markers. We applied "tigrisPlex" to 12 confiscated specimens from Russia and identified 6 individuals (3 females and 3 males), each represented by duplicated samples and all designated as Amur tigers (Panthera tigris altaica) with high confidence. This STR multiplex system can serve as an effective and versatile approach for genetic profiling of both wild and captive tigers as well as confiscated tiger products, fulfilling various conservation needs for identifying the origins of tiger samples. PMID:25950598

  19. Calibration of a Microwave Imaging System Using a Known Scatterer

    DEFF Research Database (Denmark)

    Rubæk, Tonny; Zhurbenko, Vitaliy

    2010-01-01

    An increasing number of operational microwave imaging systems have been presented in recent years, especially for medical imaging. This has increased the focus on the practical aspects of microwave imaging, such as the need for calibration, how to decrease measurement time, and how to minimize...... the effect of noise. At the Technical University of Denmark, a 32-channel microwave imaging system for breast cancer screening has been under development for some time. In this system, each antenna is equipped with its own transceiver module, containing amplifiers, switches, and a mixer. This design ensures...

  20. Laboratory and field portable system for calibrating airborne multispectral scanners

    International Nuclear Information System (INIS)

    Manufacturers of airborne multispectral scanners suggest procedures for calibration and alignment that are usually awkward and even questionable. For example, the procedures may require: separating the scanner from calibration and alignment sources by 100 feet or more, employing folding mirrors, tampering with the detectors after the procedures are finished, etc. Under the best of conditions such procedures require about three hours yielding questionable confidence in the results; under many conditions, however, procedures commonly take six to eight hours, yielding no satisfactory results. EG and G, Inc. has designed and built a calibration and alignment system for airborne scanners which solves those problems, permitting the procedures to be carried out in about two to three hours. This equipment can be quickly disassembled, transported with the scanner in all but the smallest single engine aircraft, and reassembled in a few hours. The subsystems of this equipment are commonly available from manufacturers of optical and electronic equipment. The other components are easily purchased, or fabricated. The scanner discussed is the Model DS-1260 digital line scanner manufactured by Daedalus Enterprises, Inc. It is a dual-sensor system which is operated in one of two combination of sensors: one spectrometer head (which provides simultaneous coverage in ten visible channels) and one thermal infrared detector, or simply two thermal infrared detectors

  1. Calibration systems and methods for the ANTARES neutrino telescope

    CERN Document Server

    Fehr, Felix

    2007-01-01

    The ANTARES neutrino telescope is currently being constructed in the Mediterranean Sea. The complete detector will consist of 12 strings, supplemented by an additional instrumentation line. Nine strings are at present deployed of which five are already connected to the shore and operating. Each string is equipped with 75 Optical Modules (OMs) housing the photomultipliers to detect the Cherenkov light induced by the charged particles produced in neutrino reactions. An accurate measurement of the Cherenkov photon arrival times as well as the positions and orientations of the OMs is required for a precise reconstruction of the direction of the detected neutrinos. For this purpose the ANTARES detector is provided with several system s to facilitate the calibration of the detector. The time calibration is performed using light pulses emitted from LED and laser devices. The positioning is done via acoustic triangulation using hydrophones. Additionally, local tilt angles and the orientations of the modules are measu...

  2. Calibration system for measuring the radon flux density.

    Science.gov (United States)

    Onishchenko, A; Zhukovsky, M; Bastrikov, V

    2015-06-01

    The measurement of radon flux from soil surface is the useful tool for the assessment of radon-prone areas and monitoring of radon releases from uranium mining and milling residues. The accumulation chambers with hollow headspace and chambers with activated charcoal are the most used devices for these purposes. Systematic errors of the measurements strongly depend on the geometry of the chamber and diffusion coefficient of the radon in soil. The calibration system for the attestation of devices for radon flux measurements was constructed. The calibration measurements of accumulation chambers and chambers with activated charcoal were conducted. The good agreement between the results of 2D modelling of radon flux and measurements results was observed. It was demonstrated that reliable measurements of radon flux can be obtained by chambers with activated charcoal (equivalent volume ~75 l) or by accumulation chambers with hollow headspace of ~7-10 l and volume/surface ratio (height) of >15 cm.

  3. Calibration system for measuring the radon flux density

    International Nuclear Information System (INIS)

    The measurement of radon flux from soil surface is the useful tool for the assessment of radon-prone areas and monitoring of radon releases from uranium mining and milling residues. The accumulation chambers with hollow headspace and chambers with activated charcoal are the most used devices for these purposes. Systematic errors of the measurements strongly depend on the geometry of the chamber and diffusion coefficient of the radon in soil. The calibration system for the attestation of devices for radon flux measurements was constructed. The calibration measurements of accumulation chambers and chambers with activated charcoal were conducted. The good agreement between the results of 2D modelling of radon flux and measurements results was observed. It was demonstrated that reliable measurements of radon flux can be obtained by chambers with activated charcoal (equivalent volume ∼75 l) or by accumulation chambers with hollow headspace of ∼7-10 l and volume/surface ratio (height) of >15 cm. (authors)

  4. Design and development of an ultrasound calibration phantom and system

    Science.gov (United States)

    Cheng, Alexis; Ackerman, Martin K.; Chirikjian, Gregory S.; Boctor, Emad M.

    2014-03-01

    Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the ultrasound transducer and the ultrasound image. A phantom or model with known geometry is also required. In this work, we design and test an ultrasound calibration phantom and software. The two main considerations in this work are utilizing our knowledge of ultrasound physics to design the phantom and delivering an easy to use calibration process to the user. We explore the use of a three-dimensional printer to create the phantom in its entirety without need for user assembly. We have also developed software to automatically segment the three-dimensional printed rods from the ultrasound image by leveraging knowledge about the shape and scale of the phantom. In this work, we present preliminary results from using this phantom to perform ultrasound calibration. To test the efficacy of our method, we match the projection of the points segmented from the image to the known model and calculate a sum squared difference between each point for several combinations of motion generation and filtering methods. The best performing combination of motion and filtering techniques had an error of 1.56 mm and a standard deviation of 1.02 mm.

  5. The application of a tandem dike system in Vietnam

    NARCIS (Netherlands)

    Tri, M.C.; Cong, M.V.; Verhagen, H.J.; Nghia, N.K.

    2012-01-01

    In the low-lying coastal regions coastal defense structures are usually designed with a main function to protect the hinterland from highly vulnerable of sea flooding. Sea dikes are usually the most common and important elements which form the coastal flood defense system. Sea dikes are designed at

  6. The calibration system of the GERDA muon veto Cherenkov detector

    International Nuclear Information System (INIS)

    The GERDA experiment searches for neutrinoless double beta decay (0νββ). To achieve a sensitivity of 10-3counts/(keVkgy) or better within a specific region of interest (ROI), a good background identification is needed. Therefore GERDA is located in the LNGS (Laboratori Nationali del Gran Sasso) underground facility. In addition to the good rejection of cosmic muons due to the surrounding bedrocks, a dual muon veto system has to be used. For calibration and monitoring of the muon veto, two separate systems have been developed.

  7. The calibration system of the GERDA muon veto Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, Florian, E-mail: ritter@pit.physik.uni-tuebingen.d [Kepler Centre for Astro and Particle Physics, Universitaet Tuebingen, Tuebingen (Germany); Lubsandorzhiev, Bayarto [Kepler Centre for Astro and Particle Physics, Universitaet Tuebingen, Tuebingen (Germany); Institute for Nuclear Research of RAS, Moscow (Russian Federation); Freund, Kai; Grabmayr, Peter; Jochum, Josef; Knapp, Markus; Meierhofer, Georg [Kepler Centre for Astro and Particle Physics, Universitaet Tuebingen, Tuebingen (Germany); Shaibonov, Bator [Institute for Nuclear Research of RAS, Moscow (Russian Federation)

    2010-05-21

    The GERDA experiment searches for neutrinoless double beta decay (0{nu}{beta}{beta}). To achieve a sensitivity of 10{sup -3}counts/(keVkgy) or better within a specific region of interest (ROI), a good background identification is needed. Therefore GERDA is located in the LNGS (Laboratori Nationali del Gran Sasso) underground facility. In addition to the good rejection of cosmic muons due to the surrounding bedrocks, a dual muon veto system has to be used. For calibration and monitoring of the muon veto, two separate systems have been developed.

  8. System for Measuring Elevator Guide Rail Quality and Its Calibration

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A system for measuring the quality parameters of elevator guide rails is developed. The quality parameters the system can measure include straightness, flatness, squareness, width and height of the rail. The system consists of six parts:main guideway, auxiliary guideway, reference rail, saddle, control casing and measured rail. The guide rail to be measured is mounted on a bed.The straightness errors of surfaces are checked by five linear displacement sensors mounted on the saddle. The deviation of readings from the sensor, which is in contact with top guiding surface,gives the straightness error of the surface and height of the rail. The other four sensors are used to measure side guiding surfaces respectively and give other parameters including flatness on the surfaces, squareness, width and height of the rail. A novel calibration method is also developed to calibrate the straightness motion error of the system in horizontal and vertical directions. The deflection deformation of the measured rail is fitted by using a fourth-order polynomial. Experimental results show that the uncertainty of the system on the side surfaces after compensating the straightness motion error is less than 0.01 mm, and the uncertainty of the system on the top surface after compensating the straightness motion error and the deflection deformation of the rail is less than 0.03 mm.

  9. 21 CFR 874.3310 - Hearing aid calibrator and analysis system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hearing aid calibrator and analysis system. 874... aid calibrator and analysis system. (a) Identification. A hearing aid calibrator and analysis system... sound intensity characteristics emanating from a hearing aid, master hearing aid, group hearing aid...

  10. Upgrading of the tandem

    International Nuclear Information System (INIS)

    The program of the tandem-linac accelerator system is summarized under the following headings: operating experience for the tandem, operation of the superconducting linac, upgrading of the tandem (ion sources, vacuum systems, terminal box, stripping foils, beam bunching), installation of the booster, planned accelerator system improvements, experimental facilities development at the super conducting-linac booster (new beam line, layout and installation of the 00 beam line in the new experiment area, beam optics calculations, 65-in. scattering chamber, split-pole spectrograph, sum/multiplicity detector, nuclear target making and development), and university use of the tandem accelerator

  11. Development of a Calibration and Monitoring System for GD-1 High Pressure Common Rail Diesel Engine

    Institute of Scientific and Technical Information of China (English)

    王俊席; 杨林; 冯静; 冒晓建; 卓斌

    2004-01-01

    Based on CAN calibration protocol, a new calibration and monitoring system was developed for the GD1 high pressure common rail diesel engine. CAN driver block, monitoring program and calibration program for this system were designed respectively. The inquiry mode was used in the monitoring program and the interrupt mode was used in calibration program. The calibration program was designed in structural programming model. This system provides a reliable, accurate and quick CAN bus between ECU and PC, with baud rate up to 500Kbit/s.The implementation of the compatible and universal CAN calibration protocol makes it easy to displace the system and its function modules. It also provides friendly, compatible and flexible calibration interface, and the functions of online calibration and real-time monitoring. This system was successfully used in a GD-1 high pressure common rail diesel engine and the engine performance and exhaust emissions were significantly improved.

  12. Metrology system for the calibration of multi-dof mechanisms

    Science.gov (United States)

    Zago, Lorenzo; Sarajlic, Mirsad; Chevalley, Fabien

    2014-07-01

    This paper presents a novel absolute position metrology system developed in our institute based on a concept using industrial vision by which USB cameras observe targets provided with special dots patterns. The system was originally devised for precision 2D measurements, then extended to 6-degree-of-freedom setups. This particular metrology system has been developed for testing and calibrating the precision hexapods aligning the secondary mirrors of the ESO VLTI auxiliary telescopes but its principle can be used for measuring the accuracy of any multi-degree-of-freedom mechanisms. The accuracy/resolution of the metrology system is typically 2-5 μm along linear degrees of freedom, respectively 5 arcsec for tip-tilt. This method is particularly affordable in cost, robust, yet accurate enough for most precision measurements in astronomical optomechanics.

  13. VOR - Calibration by an Airborne Integrated Navigation System

    Directory of Open Access Journals (Sweden)

    Tore Smestad

    1980-01-01

    Full Text Available A simulation study of a possible application of modern control theory is presented. The problem is to check and calibrate a VOR-station from a circling aircraft. An accurate position estimate of the circling aircraft is needed in order to calculate the errors in the received VOR-signals. The position estimate is here obtained from an integrated navigation system using an inertial navigation system (INS, a laser range-finder, angle measurements on the laser line-of-sight, and barometer readings. The range and angle measurements are fed to a Kalman filter which estimates errors in the navigation system. Simulation results show that satisfactory accuracy is obtained by this method. The paper presents a description of the proposed system, the simulation model used, simulation results and some sensitivity analysis.

  14. Towards high accuracy calibration of electron backscatter diffraction systems

    Energy Technology Data Exchange (ETDEWEB)

    Mingard, Ken [National Physical Laboratory, Hampton Road, Teddington, TW11 0LW (United Kingdom); Day, Austin, E-mail: Austin.Day@ADSci.co.uk [Aunt Daisy Scientific Ltd., Claremont House, Lydney, GL15 5DX (United Kingdom); Maurice, Claire [Ecole des Mines, Centre SMS-UMR CNRS 5146, 158 cours Fauriel, 42023 Saint Etienne Cedex 2 (France); Quested, Peter [National Physical Laboratory, Hampton Road, Teddington, TW11 0LW (United Kingdom)

    2011-04-15

    For precise orientation and strain measurements, advanced Electron Backscatter Diffraction (EBSD) techniques require both accurate calibration and reproducible measurement of the system geometry. In many cases the pattern centre (PC) needs to be determined to sub-pixel accuracy. The mechanical insertion/retraction, through the Scanning Electron Microscope (SEM) chamber wall, of the electron sensitive part of modern EBSD detectors also causes alignment and positioning problems and requires frequent monitoring of the PC. Optical alignment and lens distortion issues within the scintillator, lens and charge-coupled device (CCD) camera combination of an EBSD detector need accurate measurement for each individual EBSD system. This paper highlights and quantifies these issues and demonstrates the determination of the pattern centre using a novel shadow-casting technique with a precision of {approx}10 {mu}m or {approx}1/3 CCD pixel. -- Research highlights: {yields} Issues with accurate EBSD calibration are discussed. {yields} Optical distortion data for 17 EBSD detectors are tabulated. {yields} A new shadow-casting system is demonstrated; it gives a pattern centre precision of {approx}10 {mu}m and allows changes to be observed on the live EBSP.

  15. Calibration of PIXE-SP system of elementary analysis

    International Nuclear Information System (INIS)

    The set-up and calibration of the PIXE-SP System of Elementary Analysis located at the Institute of Physics of the University of Sao Paulo is described. The PIXE-SP, that operates with 8 MeV alpha beam, has been calibrated for elements with Z >= 11, by means of homemade evaporated standard targets of Al, Si, Bacl2, K2CrO4, Ti, Cr, Mn, Fe, Cu, Ge, Ag, Sn, and Au. Those targets are thin, homogeneous, and have been calbrated on a microbalance within an average precision of 6%. The overall precision of the PIXE-SP System is estimated in 10% for elements with 16 2 thick, irradiated with a 10 μC electric charge, shows a minimum of about 0,1 ng (approximated 4 ppm) for Mn. The PIXE-SP System has also been intercalibrated with the PIXE located at University of Gent, Belgium, by means of 12 atmospheric aerosol targets collected on two Batelle Cascade Impactors. The analyzed masses of elements with 16 <= Z < 30 agree within 20%. (Author)

  16. Results of the use of an automated electrical measuring instrument calibration system

    Science.gov (United States)

    Barbier, Pierre

    A system for calibrating digital multimeter and stimulus generators was developed. Software was written for fully automated machines, nonautomated instruments with digital output, and entirely manual machines. The advantages in terms of calibration quality, productivity, and operator motivation are stressed.

  17. Extrinsic Calibration for Vehicle-based Mobile Mapping System

    Directory of Open Access Journals (Sweden)

    SHI Limei

    2015-01-01

    Full Text Available Having the advantage of 360° imaging and rotation invariance, panoramic camera has gradually been used in mobile mapping systems(MMS. Calibration is an essential requirement to make sure that MMS can get high quality geo-information. This paper presents a way to address the extrinsic calibration for vehicle-based MMS composed of panoramic camera and Position and Orientation System (POS. Firstly, control points in the natural scene are set up, whose spatial coordinates are measured with high precision. Secondly, a panoramic spherical model is constructed and panoramic image can be projected to this model by means of spherical reverse transformation projection. Then, localize and select the control points in 3D spherical panoramic view but not in panoramic distorted image directly, the spherical coordinates of control points in panoramic image are gotten. After points correspondence is established, make use of direct geo-reference positioning equation and coordinate transformation, the translation and rotation parameters of panoramic camera relative to POS are computed. Experiments are conducted separately in space city calibration site located in Beijing and the Binhai New Area in Tianjin using our approach. Test results are listed as follows. When the GPS signal are of good quality, absolute positioning mean square error of a point is 10.3 cm in two-dimension plane and 16.5 cm in height direction; Otherwise, it is 35.4 cm in two-dimension plane and 54.8 cm in height direction. The max relative error of distance measurement is about 5 cm over a short distance (distance<3 km, which is not obviously affected by the GPS signal quality.

  18. Mars Entry Atmospheric Data System Modeling, Calibration, and Error Analysis

    Science.gov (United States)

    Karlgaard, Christopher D.; VanNorman, John; Siemers, Paul M.; Schoenenberger, Mark; Munk, Michelle M.

    2014-01-01

    The Mars Science Laboratory (MSL) Entry, Descent, and Landing Instrumentation (MEDLI)/Mars Entry Atmospheric Data System (MEADS) project installed seven pressure ports through the MSL Phenolic Impregnated Carbon Ablator (PICA) heatshield to measure heatshield surface pressures during entry. These measured surface pressures are used to generate estimates of atmospheric quantities based on modeled surface pressure distributions. In particular, the quantities to be estimated from the MEADS pressure measurements include the dynamic pressure, angle of attack, and angle of sideslip. This report describes the calibration of the pressure transducers utilized to reconstruct the atmospheric data and associated uncertainty models, pressure modeling and uncertainty analysis, and system performance results. The results indicate that the MEADS pressure measurement system hardware meets the project requirements.

  19. Calibrating a novel multi-sensor physical activity measurement system

    International Nuclear Information System (INIS)

    Advancing the field of physical activity (PA) monitoring requires the development of innovative multi-sensor measurement systems that are feasible in the free-living environment. The use of novel analytical techniques to combine and process these multiple sensor signals is equally important. This paper describes a novel multi-sensor 'integrated PA measurement system' (IMS), the lab-based methodology used to calibrate the IMS, techniques used to predict multiple variables from the sensor signals, and proposes design changes to improve the feasibility of deploying the IMS in the free-living environment. The IMS consists of hip and wrist acceleration sensors, two piezoelectric respiration sensors on the torso, and an ultraviolet radiation sensor to obtain contextual information (indoors versus outdoors) of PA. During lab-based calibration of the IMS, data were collected on participants performing a PA routine consisting of seven different ambulatory and free-living activities while wearing a portable metabolic unit (criterion measure) and the IMS. Data analyses on the first 50 adult participants are presented. These analyses were used to determine if the IMS can be used to predict the variables of interest. Finally, physical modifications for the IMS that could enhance the feasibility of free-living use are proposed and refinement of the prediction techniques is discussed

  20. Strong earthquakes knowledge base for calibrating fast damage assessment systems

    Science.gov (United States)

    Frolova, N.; Kozlov, M.; Larionov, V.; Nikolaev, A.; Suchshev, S.; Ugarov, A.

    2003-04-01

    At present Systems for fast damage and loss assessment due to strong earthquakes may use as input data: (1) information about event parameters (magnitude, depth and coordinates) issued by Alert Seismological Surveys; (2) wave-form data obtained by strong-motion seismograph network; (3) high resolution space images of the affected area obtained before and after the event. When data about magnidute, depth and location of event are used to simulate possible consequences, the reliability of estimations depends on completeness and reliability of databases on elements at risk (population and built environment); reliability of vulnerability functions of elements at risk; and errors in strong earthquakes' parameters determination by Alert Seismological Surveys. Some of these factors may be taken into account at the expense of the System calibration with usage of well documented past strong earthquakes. The paper is describing the structure and content of the knowledge base about well documented strong events, which occurred in last century. It contains the description of more than 1000 events. The data are distributed almost homogeneously as the losses due to earthquakes are concerned; the most events are in the magnitude range 6.5 -7.9. Software is created to accumulate and analyze the information about these events source parameters and social consequences. Created knowledge base is used for calibration the Fast Damage Assessment Tool, which is at present on duty with the framework of EDRIM Program. It is also used as additional information by experts who analyses the results of computations.

  1. The calibration and alignment of the LHCb RICH system

    CERN Document Server

    Papanestis, Antonis

    2008-01-01

    Hadron identification in the LHCb experiment is performed by two Ring Imaging Cherenkov (RICH) detectors, comprising three radiators and 484 Hybrid Photon Detectors (HPDs). A well calibrated and aligned RICH system is essential for providing the particle identification performance necessary for realising the physics goals. The total number of mirrors in the two RICH detectors is 116 and they must be aligned to an accuracy of 0.1 mrad in order not to degrade the performance of the system. The refractive indices $n$ of the two gas radiators, namely C$_4$F$_{10}$ and CF$_4$, are expected to change with atmospheric pressure, and the refractivity ($n$ - 1) will be monitored to an accuracy of 0.1% from physics data. The Cherenkov angle resolutions and photon yields will be calibrated using saturated Cherenkov rings and particles of known type. Both RICH detectors operate in the fringe field of the LHCb dipole magnet, which produces image distortions of the HPDs. Solutions to correct for these distortions are in the...

  2. Evolution of the JPSS Ground Project Calibration and Validation System

    Science.gov (United States)

    Purcell, Patrick; Chander, Gyanesh; Jain, Peyush

    2016-01-01

    The Joint Polar Satellite System (JPSS) is the National Oceanic and Atmospheric Administration's (NOAA) next-generation operational Earth observation Program that acquires and distributes global environmental data from multiple polar-orbiting satellites. The JPSS Program plays a critical role to NOAA's mission to understand and predict changes in weather, climate, oceans, coasts, and space environments, which supports the Nation's economy and protection of lives and property. The National Aeronautics and Space Administration (NASA) is acquiring and implementing the JPSS, comprised of flight and ground systems, on behalf of NOAA. The JPSS satellites are planned to fly in the afternoon orbit and will provide operational continuity of satellite-based observations and products for NOAA Polar-orbiting Operational Environmental Satellites (POES) and the Suomi National Polar-orbiting Partnership (SNPP) satellite. To support the JPSS Calibration and Validation (CalVal) node Government Resource for Algorithm Verification, Independent Test, and Evaluation (GRAVITE) services facilitate: Algorithm Integration and Checkout, Algorithm and Product Operational Tuning, Instrument Calibration, Product Validation, Algorithm Investigation, and Data Quality Support and Monitoring. GRAVITE is a mature, deployed system that currently supports the SNPP Mission and has been in operations since SNPP launch. This paper discusses the major re-architecture for Block 2.0 that incorporates SNPP lessons learned, architecture of the system, and demonstrates how GRAVITE has evolved as a system with increased performance. It is now a robust, stable, reliable, maintainable, scalable, and secure system that supports development, test, and production strings, replaces proprietary and custom software, uses open source software, and is compliant with NASA and NOAA standards.

  3. Hierarchical Bayesian Data Analysis in Radiometric SAR System Calibration: A Case Study on Transponder Calibration with RADARSAT-2 Data

    Directory of Open Access Journals (Sweden)

    Björn J. Döring

    2013-12-01

    Full Text Available A synthetic aperture radar (SAR system requires external absolute calibration so that radiometric measurements can be exploited in numerous scientific and commercial applications. Besides estimating a calibration factor, metrological standards also demand the derivation of a respective calibration uncertainty. This uncertainty is currently not systematically determined. Here for the first time it is proposed to use hierarchical modeling and Bayesian statistics as a consistent method for handling and analyzing the hierarchical data typically acquired during external calibration campaigns. Through the use of Markov chain Monte Carlo simulations, a joint posterior probability can be conveniently derived from measurement data despite the necessary grouping of data samples. The applicability of the method is demonstrated through a case study: The radar reflectivity of DLR’s new C-band Kalibri transponder is derived through a series of RADARSAT-2 acquisitions and a comparison with reference point targets (corner reflectors. The systematic derivation of calibration uncertainties is seen as an important step toward traceable radiometric calibration of synthetic aperture radars.

  4. Calibration Experiments for a Computer Vision Oyster Volume Estimation System

    Science.gov (United States)

    Chang, G. Andy; Kerns, G. Jay; Lee, D. J.; Stanek, Gary L.

    2009-01-01

    Calibration is a technique that is commonly used in science and engineering research that requires calibrating measurement tools for obtaining more accurate measurements. It is an important technique in various industries. In many situations, calibration is an application of linear regression, and is a good topic to be included when explaining and…

  5. Applications of small computers for systems control on the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Desktop computers operating into a CAMAC-based interface are used to control and monitor the operation of the various subsystems on the Tandem Mirror Experiment-Upgrade (TMX-U) at Lawrence Livermore National Laboratory (LLNL). These systems include: shot sequencer/master timing, neutral beam control (four consoles), magnet power system control, ion-cyclotron resonant heating (ICRH) control, thermocouple monitoring, getter system control, gas fueling system control, and electron-cyclotron resonant heating (ECRH) monitoring. Two additional computers are used to control the TMX-U neutral beam test stand and provide computer-aided repair/test and development of CAMAC modules. These machines are usually programmed in BASIC, but some codes have been interpreted into assembly language to increase speed. Details of the computer interfaces and system complexity are described as well as the evolution of the systems to their present states

  6. Expansion of the data acquisition system for the 20 MV tandem accelerator

    International Nuclear Information System (INIS)

    This report describes an expansion of the program of the data acquisition system for the 20 MV tandem accelerator. By the present expansion it became possible to change the accuisition mode or to use non-standard CAMAC modules with partial modification of the program according to well defined prescriptions. The modification can be made by writing microprograms for the MBD or appending subroutines for the reduced spectra in the LIST mode data acquisition. The new program can handle up to 32 ADC's in the standard LIST mode data acquisition. The present expansion aimed to increase the flexibility in data acquisition. It can also be applied to control experimental devices. (author)

  7. Four years of magnet system operation on the Tandem Mirror Experiment-Upgrade (TMX-U)

    International Nuclear Information System (INIS)

    During the past four years, the Tandem Mirror Experiment-Upgrade (TMX-U) magnet system has operated successfully, delivering more than 13,300 full-power shots. This paper presents the expanded physics criteria and how they affect the magnetic field design. It compares our operational results with previously defined criteria for current repeatability, cooling, duty cycle and vacuum integrity. It also details the solutions to a few operational problems, including the discovery and repair of a ground fault in the east plug Ioffe and another in an east plug cee circuit power supply. 14 refs

  8. Magnet power control system for the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    This paper describes the desktop computer/CAMAC-based system that controls the power source for the Tandem Mirror Experiment-Upgrade (TMX-U) magnet power system. Presently it contains 42 dc rectifier power supplies connected to 24 magnet coils arranged in 17 circuits. During each shot, the system delivers 22.6 MW dc to the magnets for about 3 s. The system is presently being changed to add six power supplies, two solenoidal throttle coils, and two reverse C-coils. When complete, the delivered power will increase to 36.9 MW. The closed-loop control system usually provides current (and thus, magnetic field) that is within 1% of the requested current. Achieving this accuracy required using grounding, shielding, and isolation methods to reduce noise and related problems. These are also discussed

  9. A Self-Calibrating Remote Control Chemical Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Jessica Croft

    2007-06-01

    The Susie Mine, part of the Upper Tenmile Mining Area, is located in Rimini, MT about 15 miles southwest of Helena, MT. The Upper Tenmile Creek Mining Area is an EPA Superfund site with 70 abandoned hard rock mines and several residential yards prioritized for clean up. Water from the Susie mine flows into Tenmile Creek from which the city of Helena draws part of its water supply. MSE Technology Applications in Butte, Montana was contracted by the EPA to build a treatment system for the Susie mine effluent and demonstrate a system capable of treating mine waste water in remote locations. The Idaho National Lab was contracted to design, build and demonstrate a low maintenance self-calibrating monitoring system that would monitor multiple sample points, allow remote two-way communications with the control software and allow access to the collected data through a web site. The Automated Chemical Analysis Monitoring (ACAM) system was installed in December 2006. This thesis documents the overall design of the hardware, control software and website, the data collected while MSE-TA’s system was operational, the data collected after MSE-TA’s system was shut down and suggested improvements to the existing system.

  10. 21 CFR 862.1055 - Newborn screening test system for amino acids, free carnitine, and acylcarnitines using tandem...

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Newborn screening test system for amino acids... screening test system for amino acids, free carnitine, and acylcarnitines using tandem mass spectrometry. (a) Identification. A newborn screening test system for amino acids, free carnitine, and acylcarnitines using...

  11. A versatile PCR-based tandem epitope tagging system for Streptomyces coelicolor genome.

    Science.gov (United States)

    Kim, Ji-Nu; Yi, Jeong Sang; Lee, Bo-Rahm; Kim, Eun-Jung; Kim, Min Woo; Song, Yoseb; Cho, Byung-Kwan; Kim, Byung-Gee

    2012-07-20

    Epitope tagging approaches have been widely used for the analysis of functions, interactions and subcellular distributions of proteins. However, incorporating epitope sequence into protein loci in Streptomyces is time-consuming procedure due to the absence of the versatile tagging methods. Here, we developed a versatile PCR-based tandem epitope tagging tool for the Streptomyces genome engineering. We constructed a series of template plasmids that carry repeated sequence of c-myc epitope, Flp recombinase target (FRT) sites, and apramycin resistance marker to insert epitope tags into any desired spot of the chromosomal loci. A DNA module which includes the tandem epitope-encoding sequence and a selectable marker was amplified by PCR with primers that carry homologous extensions to the last portion and downstream region of the targeted gene. We fused the epitope tags at the 3' region of global transcription factors of Streptomyces coelicolor to test the validity of this system. The proper insertion of the epitope tag was confirmed by PCR and western blot analysis. The recombinants showed the identical phenotype to the wild-type that proved the conservation of in vivo function of the tagged proteins. Finally, the direct binding targets were successfully detected by chromatin immunoprecipitation with the increase in the signal-to-noise ratio. The epitope tagging system describes here would provide wide applications to study the protein functions in S. coelicolor. PMID:22704935

  12. Further investigation into calibration techniques for a magnetic suspension and balance system

    Science.gov (United States)

    Eskins, J.

    1986-01-01

    Calibrations performed on three different magnetic cores for wind tunnel models suspended in the Southampton University Magnetic Suspension and Balance System (SUMSBS) are detailed. The first core investigated was the Southampton University pilot Superconducting Solenoid model, first flown in July 1983. Static calibrations of lift force, drag force and pitching moment, together with lift force and pitching moment calibrations determined by the dynamic method are detailed in this report. Other types of core investigated in a similar manner were conventional permanent magnets, Alnico and samarium-cobalt. All static calibrations gave a linear dependence of force on electromagnet current as expected. Dynamic calibrations are faster to perform but are proving to be not as easily analyzed as static calibrations. There are still some effects to be explained but dynamic lift calibration results were obtained agreeing to within 2 percent of the static calibration value.

  13. CRYOGENIC SYSTEM FOR PRECISE CALIBRATION OF TEMPERATURE SENSORS

    Directory of Open Access Journals (Sweden)

    A. N. Solovyev

    2016-09-01

    Full Text Available A calibration technique for cryogenic temperature sensors is proposed and implemented. The experimental setup is based on the helium cryogenerator, providing calibration of the temperature sensors of various types in wide temperature range, including cryogenic band (25-100K. A condensation thermometer with hydrogen, neon, argon and xenon as working gases is used as a reference sensor. The experimental setup was successfully used for precise (0.1K precision calibration of platinum resistive temperature detectors (Pt-100 for international nuclear physics experiments MuSun and PolFusion. The setup can also be used for calibration of temperature sensors of the other types.

  14. A python based interface for the tandem-linac control system

    International Nuclear Information System (INIS)

    The control system for the Tandem-LINAC accelerator system at IUAC is a client-server design running on a network of PCs under the GNU/Linux operating system. The computers connected to the devices in the accelerator run a server program. The computers providing the user interface runs different kinds of client programs that communicates to the servers over a TCT/IP network to control/monitor the accelerator parameters. Both the programs were written in C language and some programming expertise was required to write the client programs. The addition of a Python language interface has enabled the users to write programs for specific tasks like data logging and partial automation of the operation with minimal effort. (author)

  15. Flux density calibration in diffuse optical tomographic systems.

    Science.gov (United States)

    Biswas, Samir Kumar; Rajan, Kanhirodan; Vasu, Ram M

    2013-02-01

    The solution of the forward equation that models the transport of light through a highly scattering tissue material in diffuse optical tomography (DOT) using the finite element method gives flux density (Φ) at the nodal points of the mesh. The experimentally measured flux (Umeasured) on the boundary over a finite surface area in a DOT system has to be corrected to account for the system transfer functions (R) of various building blocks of the measurement system. We present two methods to compensate for the perturbations caused by R and estimate true flux density (Φ) from Umeasuredcal. In the first approach, the measurement data with a homogeneous phantom (Umeasuredhomo) is used to calibrate the measurement system. The second scheme estimates the homogeneous phantom measurement using only the measurement from a heterogeneous phantom, thereby eliminating the necessity of a homogeneous phantom. This is done by statistically averaging the data (Umeasuredhetero) and redistributing it to the corresponding detector positions. The experiments carried out on tissue mimicking phantom with single and multiple inhomogeneities, human hand, and a pork tissue phantom demonstrate the robustness of the approach.

  16. A real-time camera calibration system based on OpenCV

    Science.gov (United States)

    Zhang, Hui; Wang, Hua; Guo, Huinan; Ren, Long; Zhou, Zuofeng

    2015-07-01

    Camera calibration is one of the essential steps in the computer vision research. This paper describes a real-time OpenCV based camera calibration system, and developed and implemented in the VS2008 environment. Experimental results prove that the system to achieve a simple and fast camera calibration, compared with MATLAB, higher precision and does not need manual intervention, and can be widely used in various computer vision system.

  17. Acoustic Self-Calibrating System for Indoor Smart Phone Tracking

    Directory of Open Access Journals (Sweden)

    Alexander Ens

    2015-01-01

    Full Text Available This paper presents an acoustic indoor localization system for commercial smart phones that emit high pitched acoustic signals beyond the audible range. The acoustic signals with an identifier code modulated on the signal are detected by self-built receivers which are placed at the ceiling or on walls in a room. The receivers are connected in a Wi-Fi network, such that they synchronize their clocks and exchange the time differences of arrival (TDoA of the received chirps. The location of the smart phone is calculated by TDoA multilateration. The precise time measuring of sound enables high precision localization in indoor areas. Our approach enables applications that require high accuracy, such as finding products in a supermarket or guiding blind people through complicated buildings. We have evaluated our system in real-world experiments using different algorithms for calibration-free localization and different types of sound signals. The adaptive GOGO-CFAR threshold enables a detection of 48% of the chirp pulses even at a distance of 30 m. In addition, we have compared the trajectory of a pedestrian carrying a smart phone to reference positions of an optic system. Consequently, the localization error is observed to be less than 30 cm.

  18. The LLNL Multiuser Tandem Laboratory computer-controlled radiation monitoring system

    International Nuclear Information System (INIS)

    The Physics Department of the Lawrence Livermore National Laboratory (LLNL) recently constructed a Multiuser Tandem Laboratory (MTL) to perform a variety of basic and applied measurement programs. The laboratory and its research equipment were constructed with support from a consortium of LLNL Divisions, Sandia National Laboratories Livermore, and the University of California. Primary design goals for the facility were inexpensive construction and operation, high beam quality at a large number of experimental stations, and versatility in adapting to new experimental needs. To accomplish these goals, our main design decisions were to place the accelerator in an unshielded structure, to make use of reconfigured cyclotrons as effective switching magnets, and to rely on computer control systems for both radiological protection and highly reproducible and well-characterized accelerator operation. This paper addresses the radiological control computer system

  19. A Java-based control system for the Orsay tandem accelerator

    Indian Academy of Sciences (India)

    Dominique Delbourg; Gérard Penillault; Tran Khan Tuong; Martial Decourt; Nicole Borome; Henri Harroch; Bertrand Lessellier; Bernard Waast; Jean Pierre Mouffron

    2002-12-01

    A new control system was designed for the tandem MP-9 at Orsay. Because of the existing devices located on high voltage platforms and the lack of space inside the accelerator, in-house electronic cards based on micro-controllers and an optical fieldbus were developed to collect data. VME processors under VxWorks, a real time operating system, manage the fieldbus, concentrate the accelerator information and transmit it to the supervisory software through the ethernet network. This software consists of a collection of Java virtual machines (JVM) running on several Unix work-stations and PCs under Windows. Some of the Java virtual machines manage apparatus, instruments, local display and connections to an object database and VME concentrators. Others manage general synoptics. JVMs communicate between themselves with RMI protocol and JRPC with VME concentrators. So the supervisory software can be spread over several control stations throughout the network.

  20. A Java-based control system for the Orsay tandem accelerator

    International Nuclear Information System (INIS)

    A new control system was designed for the Tandem MP-9 at Orsay. Because of the existing devices located on high voltage platforms and the lack of space inside the accelerator, in-house electronic cards based on micro-controllers and an optical fieldbus were developed to collect data. VME processors under VxWorks, a real time operating system, manage the fieldbus, concentrate the accelerator information and transmit it to the supervisory software through the ethernet network. This software consists of a collection of Java virtual machines (JVM) running on several Unix workstations and PCs under Windows. Some of the Java virtual machines manage apparatus, instruments, local display and connections to an object database and VME concentrators. Others manage general synoptics. JVMs communicate between themselves with RMI protocol and JRPC with VME concentrators. So the supervisory software can be spread over several control stations throughout the network. (author)

  1. Note: An improved calibration system with phase correction for electronic transformers with digital output

    International Nuclear Information System (INIS)

    The existing electronic transformer calibration systems employing data acquisition cards cannot satisfy some practical applications, because the calibration systems have phase measurement errors when they work in the mode of receiving external synchronization signals. This paper proposes an improved calibration system scheme with phase correction to improve the phase measurement accuracy. We employ NI PCI-4474 to design a calibration system, and the system has the potential to receive external synchronization signals and reach extremely high accuracy classes. Accuracy verification has been carried out in the China Electric Power Research Institute, and results demonstrate that the system surpasses the accuracy class 0.05. Furthermore, this system has been used to test the harmonics measurement accuracy of all-fiber optical current transformers. In the same process, we have used an existing calibration system, and a comparison of the test results is presented. The system after improvement is suitable for the intended applications

  2. Note: An improved calibration system with phase correction for electronic transformers with digital output

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Han-miao, E-mail: chenghanmiao@hust.edu.cn; Li, Hong-bin, E-mail: lihongbin@hust.edu.cn [CEEE of Huazhong University of Science and Technology, Wuhan 430074 (China); State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan 430074 (China)

    2015-08-15

    The existing electronic transformer calibration systems employing data acquisition cards cannot satisfy some practical applications, because the calibration systems have phase measurement errors when they work in the mode of receiving external synchronization signals. This paper proposes an improved calibration system scheme with phase correction to improve the phase measurement accuracy. We employ NI PCI-4474 to design a calibration system, and the system has the potential to receive external synchronization signals and reach extremely high accuracy classes. Accuracy verification has been carried out in the China Electric Power Research Institute, and results demonstrate that the system surpasses the accuracy class 0.05. Furthermore, this system has been used to test the harmonics measurement accuracy of all-fiber optical current transformers. In the same process, we have used an existing calibration system, and a comparison of the test results is presented. The system after improvement is suitable for the intended applications.

  3. Electronics and Calibration system for the CMS Beam Halo Monitor

    CERN Document Server

    Tosi, Nicolo

    2014-01-01

    In the context of increasing luminosity of LHC, it will be important to accurately measure the Machine Induced Background. A new monitoring system will be installed in the CMS cavern for measuring the beam background at high radius. This detector is composed of synthetic quartz Cherenkov radiators, coupled to fast photomultiplier tubes (PMT). The readout chain of this detector will make use of many components developed for the Phase 1 upgrade to the CMS Hadron Calorimeter electronics, with a dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal will be digitized by a charge integrating ASIC (QIE10), providing both the signal rise time and the charge integrated over one bunch crossing.The backend electronics will record bunch-by-bunch histograms, which will be published to CMS and the LHC using the newly designed CMS beam instrumentation specific DAQ. A calibration monitoring system has been designed to generate triggered pulses of light to monitor the efficiency of the sys...

  4. Mammography calibration qualities establishment in a Mo-Mo clinical system

    International Nuclear Information System (INIS)

    In this study the mammography calibration qualities were established in a clinical mammography system. The objective is to provide the IPEN instruments calibration laboratory with both mammography calibration methods (using a clinical and an industrial system). The results showed a good behavior of mammography equipment, in terms of kVp, PPV and exposure time. The additional filtration of molybdenum is adequate, air-kerma rates were determined and spectra were obtained. (author)

  5. Mammography calibration qualities establishment in a Mo-Mo clinical system

    Energy Technology Data Exchange (ETDEWEB)

    Correa, E.L.; Santos, L.R. dos; Vivolo, V.; Potiens, M.P.A., E-mail: educorrea1905@gmail.com [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    In this study the mammography calibration qualities were established in a clinical mammography system. The objective is to provide the IPEN instruments calibration laboratory with both mammography calibration methods (using a clinical and an industrial system). The results showed a good behavior of mammography equipment, in terms of kVp, PPV and exposure time. The additional filtration of molybdenum is adequate, air-kerma rates were determined and spectra were obtained. (author)

  6. Calibration and validation of measurement system. Wave Dragon, Nissum Bredning

    Energy Technology Data Exchange (ETDEWEB)

    Kofoed, J.P-; Riemann, S.; Knapp, W.

    2004-03-01

    This report deals with the calibration of the measuring equipment on board the Wave Dragon, Nissum Bredning (WD-NB) prototype. The report covers the following instruments on board WD-NB: 1) Pressure transducers. 2) Force transducers. 3) Accelerometers. 4) Displacement sensors. 5) Strain gauges. 6) Inclinometers. All of these instruments are connected to the HBM MGC+ amplifier and data acquisition unit. In the following the calibration will be dealt with individually. Furthermore, a preliminary calibration of the siphon and dummy turbines has been carried out and this is also described in the following. (au)

  7. Generic System for Remote Testing and Calibration of Measuring Instruments: Security Architecture

    Science.gov (United States)

    Jurčević, M.; Hegeduš, H.; Golub, M.

    2010-01-01

    Testing and calibration of laboratory instruments and reference standards is a routine activity and is a resource and time consuming process. Since many of the modern instruments include some communication interfaces, it is possible to create a remote calibration system. This approach addresses a wide range of possible applications and permits to drive a number of different devices. On the other hand, remote calibration process involves a number of security issues due to recommendations specified in standard ISO/IEC 17025, since it is not under total control of the calibration laboratory personnel who will sign the calibration certificate. This approach implies that the traceability and integrity of the calibration process directly depends on the collected measurement data. The reliable and secure remote control and monitoring of instruments is a crucial aspect of internet-enabled calibration procedure.

  8. Development and application of a dosimetric methodology of therapeutic X radiation beams using a tandem system

    International Nuclear Information System (INIS)

    In radiotherapy the use of orthovoltage X radiation beams is still recommended; to obtain satisfactory results, a periodic control is necessary to check the performance of the ionization chambers and the radiation beams characteristics. This control is performed by using standard dosimetric procedures, as for example the determination of half-value layers and the absorbed dose rates. A Tandem system was established in this work using a pair of ionization chambers (a thimble type and a superficial type) used for measures in a medical institution, in substitution to the routine conventional procedure of determination of half-value layers using absorbers. The results obtained show the application of this method in dosimetric procedures of orthovoltage beams (radiotherapy) as a complement for a quality control program. (author)

  9. Uncertainty Analysis of the Single-Vector Force Balance Calibration System

    Science.gov (United States)

    Parker, Peter A.; Liu, Tianshu

    2002-01-01

    This paper presents an uncertainty analysis of the Single-Vector Force Balance Calibration System (SVS). This study is focused on the uncertainty involved in setting the independent variables during the calibration experiment. By knowing the uncertainty in the calibration system, the fundamental limits of the calibration accuracy of a particular balance can be determined. A brief description of the SVS mechanical system is provided. A mathematical model is developed to describe the mechanical system elements. A sensitivity analysis of these parameters is carried out through numerical simulations to assess the sensitivity of the total uncertainty to the elemental error sources. These sensitivity coefficients provide valuable information regarding the relative significance of the elemental sources of error. An example calculation of the total uncertainty for a specific balance is provided. Results from this uncertainty analysis are specific to the Single-Vector System, but the approach is broad in nature and therefore applicable to other measurement and calibration systems.

  10. Calibration Standards for Surface Topography Measuring Systems down to Nanometric Range

    DEFF Research Database (Denmark)

    Trumpold, H.; De Chiffre, Leonardo; Andreasen, Jan Lasson;

    Background For the precise and accurate measurement of surface topography a whole range of surface detection systems is available. With their application in research and production problems arise due to the lack of traceable standard artefacts for the instrument calibration in X, Y and Z directions...... and for the calibration of filters. Existing ISO standards on calibration specimens are inadequate and limited in that they only cover contacting instruments and only partially the measuring ranges for these instruments. The whole range of non-contacting instruments are not covered despite their increasing use...... in industries ranging from automotive manufacture to ultraprecision manufacture of data storage systems and compact discs. Objectives The project is concerned with developing calibration standards including their production methods and calibration procedures as a consistent means of calibrating different types...

  11. Reflective terahertz (THz) imaging: system calibration using hydration phantoms

    Science.gov (United States)

    Bajwa, Neha; Garritano, James; Lee, Yoon Kyung; Tewari, Priyamvada; Sung, Shijun; Maccabi, Ashkan; Nowroozi, Bryan; Babakhanian, Meghedi; Sanghvi, Sajan; Singh, Rahul; Grundfest, Warren; Taylor, Zachary

    2013-02-01

    Terahertz (THz) hydration sensing continues to gain traction in the medical imaging community due to its unparalleled sensitivity to tissue water content. Rapid and accurate detection of fluid shifts following induction of thermal skin burns as well as remote corneal hydration sensing have been previously demonstrated in vivo using reflective, pulsed THz imaging. The hydration contrast sensing capabilities of this technology were recently confirmed in a parallel 7 Tesla Magnetic Resonance (MR) imaging study, in which burn areas are associated with increases in local mobile water content. Successful clinical translation of THz sensing, however, still requires quantitative assessments of system performance measurements, specifically hydration concentration sensitivity, with tissue substitutes. This research aims to calibrate the sensitivity of a novel, reflective THz system to tissue water content through the use of hydration phantoms for quantitative comparisons of THz hydration imagery.Gelatin phantoms were identified as an appropriate tissue-mimicking model for reflective THz applications, and gel composition, comprising mixtures of water and protein, was varied between 83% to 95% hydration, a physiologically relevant range. A comparison of four series of gelatin phantom studies demonstrated a positive linear relationship between THz reflectivity and water concentration, with statistically significant hydration sensitivities (p < .01) ranging between 0.0209 - 0.038% (reflectivity: %hydration). The THz-phantom interaction is simulated with a three-layer model using the Transfer Matrix Method with agreement in hydration trends. Having demonstrated the ability to accurately and noninvasively measure water content in tissue equivalent targets with high sensitivity, reflective THz imaging is explored as a potential tool for early detection and intervention of corneal pathologies.

  12. Systematic calibration of an integrated x-ray and optical tomography system for preclinical radiation research

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yidong, E-mail: yidongyang@med.miami.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 and Department of Radiation Oncology, University of Miami School of Medicine, Miami, Florida 33136 (United States); Wang, Ken Kang-Hsin; Wong, John W. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States); Eslami, Sohrab; Iordachita, Iulian I. [Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Patterson, Michael S. [Juravinski Cancer Centre and Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S4K1 (Canada)

    2015-04-15

    Purpose: The cone beam computed tomography (CBCT) guided small animal radiation research platform (SARRP) has been developed for focal tumor irradiation, allowing laboratory researchers to test basic biological hypotheses that can modify radiotherapy outcomes in ways that were not feasible previously. CBCT provides excellent bone to soft tissue contrast, but is incapable of differentiating tumors from surrounding soft tissue. Bioluminescence tomography (BLT), in contrast, allows direct visualization of even subpalpable tumors and quantitative evaluation of tumor response. Integration of BLT with CBCT offers complementary image information, with CBCT delineating anatomic structures and BLT differentiating luminescent tumors. This study is to develop a systematic method to calibrate an integrated CBCT and BLT imaging system which can be adopted onboard the SARRP to guide focal tumor irradiation. Methods: The integrated imaging system consists of CBCT, diffuse optical tomography (DOT), and BLT. The anatomy acquired from CBCT and optical properties acquired from DOT serve as a priori information for the subsequent BLT reconstruction. Phantoms were designed and procedures were developed to calibrate the CBCT, DOT/BLT, and the entire integrated system. Geometrical calibration was performed to calibrate the CBCT system. Flat field correction was performed to correct the nonuniform response of the optical imaging system. Absolute emittance calibration was performed to convert the camera readout to the emittance at the phantom or animal surface, which enabled the direct reconstruction of the bioluminescence source strength. Phantom and mouse imaging were performed to validate the calibration. Results: All calibration procedures were successfully performed. Both CBCT of a thin wire and a euthanized mouse revealed no spatial artifact, validating the accuracy of the CBCT calibration. The absolute emittance calibration was validated with a 650 nm laser source, resulting in a 3

  13. Systematic calibration of an integrated x-ray and optical tomography system for preclinical radiation research

    International Nuclear Information System (INIS)

    Purpose: The cone beam computed tomography (CBCT) guided small animal radiation research platform (SARRP) has been developed for focal tumor irradiation, allowing laboratory researchers to test basic biological hypotheses that can modify radiotherapy outcomes in ways that were not feasible previously. CBCT provides excellent bone to soft tissue contrast, but is incapable of differentiating tumors from surrounding soft tissue. Bioluminescence tomography (BLT), in contrast, allows direct visualization of even subpalpable tumors and quantitative evaluation of tumor response. Integration of BLT with CBCT offers complementary image information, with CBCT delineating anatomic structures and BLT differentiating luminescent tumors. This study is to develop a systematic method to calibrate an integrated CBCT and BLT imaging system which can be adopted onboard the SARRP to guide focal tumor irradiation. Methods: The integrated imaging system consists of CBCT, diffuse optical tomography (DOT), and BLT. The anatomy acquired from CBCT and optical properties acquired from DOT serve as a priori information for the subsequent BLT reconstruction. Phantoms were designed and procedures were developed to calibrate the CBCT, DOT/BLT, and the entire integrated system. Geometrical calibration was performed to calibrate the CBCT system. Flat field correction was performed to correct the nonuniform response of the optical imaging system. Absolute emittance calibration was performed to convert the camera readout to the emittance at the phantom or animal surface, which enabled the direct reconstruction of the bioluminescence source strength. Phantom and mouse imaging were performed to validate the calibration. Results: All calibration procedures were successfully performed. Both CBCT of a thin wire and a euthanized mouse revealed no spatial artifact, validating the accuracy of the CBCT calibration. The absolute emittance calibration was validated with a 650 nm laser source, resulting in a 3

  14. Experimental Results of Site Calibration and Sensitivity Measurements in OTR for UWB Systems

    Science.gov (United States)

    Viswanadham, Chandana; Rao, P. Mallikrajuna

    2016-08-01

    System calibration and parameter accuracy measurement of electronic support measures (ESM) systems is a major activity, carried out by electronic warfare (EW) engineers. These activities are very critical and needs good understanding in the field of microwaves, antennas, wave propagation, digital and communication domains. EW systems are broad band, built with state-of-the art electronic hardware, installed on different varieties of military platforms to guard country's security from time to time. EW systems operate in wide frequency ranges, typically in the order of thousands of MHz, hence these are ultra wide band (UWB) systems. Few calibration activities are carried within the system and in the test sites, to meet the accuracies of final specifications. After calibration, parameters are measured for their accuracies either in feed mode by injecting the RF signals into the front end or in radiation mode by transmitting the RF signals on to system antenna. To carry out these activities in radiation mode, a calibrated open test range (OTR) is necessary in the frequency band of interest. Thus site calibration of OTR is necessary to be carried out before taking up system calibration and parameter measurements. This paper presents the experimental results of OTR site calibration and sensitivity measurements of UWB systems in radiation mode.

  15. The Photomultiplier Tube Calibration System of the MicroBooNE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Conrad, J. [MIT; Jones, B. J.P. [MIT; Moss, Z. [MIT; Strauss, T. [Bern U., LHEP; Toups, M. [MIT

    2015-06-03

    We report on the design and construction of a LED-based fiber calibration system for large liquid argon time projection detectors. This system was developed to calibrate the optical systems of the MicroBooNE experiment. As well as detailing the materials and installation procedure, we provide technical drawings and specifications so that the system may be easily replicated in future LArTPC detectors.

  16. A Laser Frequency Comb System for Absolute Calibration of the VTT Echelle Spectrograph

    CERN Document Server

    Doerr, H -P; Holzwarth, R; Schmidt, T Kentischer und W

    2012-01-01

    A wavelength calibration system based on a laser frequency comb (LFC) was developed in a co-operation between the Kiepenheuer-Institut f\\"ur Sonnenphysik, Freiburg, Germany and the Max-Planck-Institut f\\"ur Quantenoptik, Garching, Germany for permanent installation at the German Vacuum Tower Telescope (VTT) on Tenerife, Canary Islands. The system was installed successfully in October 2011. By simultaneously recording the spectra from the Sun and the LFC, for each exposure a calibration curve can be derived from the known frequencies of the comb modes that is suitable for absolute calibration at the meters per second level. We briefly summarize some topics in solar physics that benefit from absolute spectroscopy and point out the advantages of LFC compared to traditional calibration techniques. We also sketch the basic setup of the VTT calibration system and its integration with the existing echelle spectrograph.

  17. A Laser Frequency Comb System for Absolute Calibration of the VTT Echelle Spectrograph

    Science.gov (United States)

    Doerr, H.-P.; Steinmetz, T.; Holzwarth, R.; Kentischer, T.; Schmidt, W.

    2012-10-01

    A wavelength calibration system based on a laser frequency comb (LFC) was developed in a co-operation between the Kiepenheuer-Institut für Sonnenphysik, Freiburg, Germany and the Max-Planck-Institut für Quantenoptik, Garching, Germany for permanent installation at the German Vacuum Tower Telescope (VTT) on Tenerife, Canary Islands. The system was installed successfully in October 2011. By simultaneously recording the spectra from the Sun and the LFC, for each exposure a calibration curve can be derived from the known frequencies of the comb modes that is suitable for absolute calibration at the meters per second level. We briefly summarize some topics in solar physics that benefit from absolute spectroscopy and point out the advantages of LFC compared to traditional calibration techniques. We also sketch the basic setup of the VTT calibration system and its integration with the existing echelle spectrograph.

  18. Calibration Report for the WRAP Facility Gamma Energy Analysis System [104-ND-06-102A

    Energy Technology Data Exchange (ETDEWEB)

    WILLS, C.E.

    2000-02-15

    The Waste Receiving And Processing facility (WRAP) adheres to providing gamma-ray spectroscopy instrument calibrations traceable to the National Institute for Standards and Technology (NIST) standards. The detectors are used to produce quantitative results for the Waste Isolation Pilot Plant (WIPP) and must meet calibration programmatic calibration goals. Instruments must meet portions of ANSI N42.14, 1978 guide for Germanium detectors. The Non-Destructive Assay (NDA) Gamma Energy Analysis (GEA) utilizes NIST traceable line source standards for the detector system calibrations. The counting configuration is a series of drums containing the line sources and different density filler matrices. The drums are used to develop system efficiencies with respect to density. The efficiency and density correction factors are required for the processing of drummed waste materials of similar densities. The calibration verification is carried out after the calibration is deemed final, by counting a second drum of NIST traceable sources. Three in-depth calibrations have been completed on one of the two systems to date, the first being the system acceptance plan. This report has a secondary function; that being the development of the instrument calibration errors which are to be folded into the Total Instrument Uncertainty document, HNF-4050.

  19. An Incremental Target-Adapted Strategy for Active Geometric Calibration of Projector-Camera Systems

    Directory of Open Access Journals (Sweden)

    Hsiang-Jen Chien

    2013-02-01

    Full Text Available The calibration of a projector-camera system is an essential step toward accurate 3-D measurement and environment-aware data projection applications, such as augmented reality. In this paper we present a two-stage easy-to-deploy strategy for robust calibration of both intrinsic and extrinsic parameters of a projector. Two key components of the system are the automatic generation of projected light patterns and the incremental calibration process. Based on the incremental strategy, the calibration process first establishes a set of initial parameters, and then it upgrades these parameters incrementally using the projection and captured images of dynamically-generated calibration patterns. The scene-driven light patterns allow the system to adapt itself to the pose of the calibration target, such that the difficulty in feature detection is greatly lowered. The strategy forms a closed-loop system that performs self-correction as more and more observations become available. Compared to the conventional method, which requires a time-consuming process for the acquisition of dense pixel correspondences, the proposed method deploys a homography-based coordinate computation, allowing the calibration time to be dramatically reduced. The experimental results indicate that an improvement of 70% in reprojection errors is achievable and 95% of the calibration time can be saved.

  20. Calibration Report for the WRAP Facility Gamma Energy Analysis System (104-ND-06-102A)

    Energy Technology Data Exchange (ETDEWEB)

    WILLS, C.E.

    2000-03-13

    The Waste Receiving And Processing facility (WRAP) adheres to providing gamma-ray spectroscopy instrument calibrations traceable to the National Institute for Standards and Technology (NIST) standard{sup (4)}. The detectors are used to produce quantitative results for the Waste Isolation Pilot Plant (WIPP) and must meet calibration programmatic calibration goals. Instruments must meet portions of ANSI N42.14, 1978 guide for Germanium detectors. The Non-Destructive Assay (NDA) Gamma Energy Analysis (GEA) utilizes NIST traceable line source standards for the detector system calibrations. The counting configuration is a series of drums containing the line sources and different density filler matrices. The drums are used to develop system efficiencies with respect to density. The efficiency and density correction factors are required for the processing of drummed waste materials of similar densities. The calibration verification is carried out after the calibration is deemed final, by counting a second drum of NIST traceable sources. Three in-depth calibrations have been completed on one of the two systems to date, the first being the system acceptance plan. This report has a secondary function; that being the development of the instrument calibration errors which are to be folded into the Total Instrument Uncertainty document, HNF-4050.

  1. Opticle fibre calibration system and adaptive power supply

    CERN Document Server

    Cvach, J; Kovalcuk, M; Kvasnicka, J; Polak, I; Smolik, J

    2015-01-01

    We summarize the recent activity of our group in the calibration, monitoring and gain stabilization of photodetectors, primarily silicon photomultipliers, in calorimeters using scintillator as active medium. The task originally solved for the CALICE analog hadron calorimeter founds application in other experiments.

  2. 40 CFR 92.116 - Engine output measurement system calibrations.

    Science.gov (United States)

    2010-07-01

    ... engineering practice. (4) When calibrating the engine flywheel torque transducer, any lever arm used to... horizontal lever arm distance, corrected for the hanging torque of the lever arm. (i) The lever-arm dead... gravitational constant at the test site may be accounted for if desired. (B) Lever arm. A lever arm with...

  3. Available energy analysis of new tandem double-capillary tube refrigeration system for refrigerator-freezers

    Institute of Scientific and Technical Information of China (English)

    Maogang HE; Xinzhou SONG; Ying ZHANG; Jiantao ZHANG

    2008-01-01

    A new tandem double-capillary tube refri-geration system for refrigerator-freezers is proposed. A capillary tube was added between the two evaporators in the fresh and frozen food storage chests to raise the evaporation temperature of the refrigerating chamber, and reduce the heat exchange temperature difference and the available energy loss. Peng-Robinson (P-R) equation of state was adopted to calculate the thermodynamic properties of the refrigerants, and the available energy analysis of the vapor compression refrigeration cycle was programmed to calculate the thermodynamic perfor-mances of the new and the conventional refrigeration cycle of the refrigerator-freezer. The calculation results show that the available energy efficiency of the conven-tional refrigeration cycle of the refrigerator-freezer is 21.20% and 20.57%, respectively when the refrigerant is R12 and R134a, while that of the double-capillary tube refrigeration cycle of the refrigerator-freezer is 23.97% and 23.44%, respectively. By comparison, the available energy efficiency of the new refrigeration system increases by 13.07% and 13.95%, respectively.

  4. Development of procedures to ensure quality and integrity in Tandem Mirror Experiment-Upgrade (TMX-U) diagnostics systems

    International Nuclear Information System (INIS)

    The diagnostic systems for Tandem Mirror Experiment-Upgrade (TMX-U) have grown from eleven initial systems to more than twenty systems. During operation, diagnostic system modifications are sometimes required to complete experimental objectives. Also, during operations new diagnostic systems are being developed and implemented. To ensure and maintain the quality and integrity of the data signals, a set of plans and systematic actions are being developed. This paper reviews the procedures set in place to maintain the integrity of existing data systems and ensure the performance objectives of new diagnostics being added

  5. SU-D-BRF-05: A Novel System to Provide Real-Time Image-Guidance for Intrauterine Tandem Insertion and Placement

    Energy Technology Data Exchange (ETDEWEB)

    Price, M; Fontenot, J [pF Biomedical Solutions LLC, Baton Rouge, LA (United States)

    2014-06-01

    Purpose: To develop a system that provides real-time image-guidance for intrauterine tandem insertion and placement for brachytherapy. Methods: The conceptualized system consists of an intrauterine tandem with a transparent, lensed tip, a flexible miniature fiber optic scope, light source and interface for CCD coupling. The tandem tip was designed to act as a lens providing a wide field-of-view (FOV) with minimal image distortion and focus length appropriate for the application. The system is designed so that once inserted, the image-guidance component of the system can be removed and brachytherapy can be administered without interfering with source transport or disturbing tandem placement. Proof-of-principle studies were conducted to assess the conceptualized system's (1) lens functionality (clarity, focus and FOV) (2) and ability to visualize the cervical os of a female placed in the lithotomy position. Results: A prototype of this device was constructed using a commercial tandem modified to incorporate a transparent tip that internally coupled with a 1.9mm diameter fiber optic cable. The 900mm-long cable terminated at an interface that provided illumination as well as facilitated visualization of patient anatomy on a computer. The system provided a 23mm FOV with a focal length of 1cm and provided clear visualization of the cervix, cervical fornix and cervical os. The optical components of the system are easily removed without perturbing the position of a tandem placed in a common fixation clamp. Conclusion: Clinicians frequently encounter difficulty inserting an intrauterine tandem through the cervical os, circumventing fibrotic tissue or masses within the uterus, and positioning the tandem without perforating the uterus. To mitigate these challenges, we have designed and conducted proof-of- principle studies to discern the utility of a prototype device that provides real-time image-guidance for intrauterine tandem placement using fiber optic components.

  6. Alternative Methodologies for LiDAR System Calibration

    OpenAIRE

    Jacky Chow; Ana Paula Kersting; Ki In Bang; Ayman Habib

    2010-01-01

    Over the last few years, LiDAR has become a popular technology for the direct acquisition of topographic information. In spite of the increasing utilization of this technology in several applications, its accuracy potential has not been fully explored. Most of current LiDAR calibration techniques are based on empirical and proprietary procedures that demand the system’s raw measurements, which may not be always available to the end-user. As a result, we can still observe systematic discrepanc...

  7. Computer-Based Simulation and Test System for the Calibration of EFI Engine

    Institute of Scientific and Technical Information of China (English)

    赵长禄; 张付军; 黄英; 葛蕴珊; 刘福水

    2004-01-01

    A computer-based simulation and test system is developed. This system has the following functions: producing the initial control MAP with good accuracy, calibrating the electronic control unit (ECU) on-line, identifying the dynamic transfer functions for air/fuel ratio, idle speed and ignition timing control. So the experiment work is reduced and the calibration is accelerated. In order to increase the simulation accuracy of the initial control MAP, the mathematical models are not only based on theoretical equations, but also on the control data of reference working points, which is obtained by the on-line calibration of special engines. The application of this system on a mini-car shows that the simulated control MAP has good accuracy, the interface of the system is friendly, the integrated simulation and test system is a powerful aid for EFI engine calibration and the development speed is accelerated.

  8. Alignment of the Measurement Scale Mark during Immersion Hydrometer Calibration Using an Image Processing System

    Science.gov (United States)

    Peña-Perez, Luis Manuel; Pedraza-Ortega, Jesus Carlos; Ramos-Arreguin, Juan Manuel; Arriaga, Saul Tovar; Fernandez, Marco Antonio Aceves; Becerra, Luis Omar; Hurtado, Efren Gorrostieta; Vargas-Soto, Jose Emilio

    2013-01-01

    The present work presents an improved method to align the measurement scale mark in an immersion hydrometer calibration system of CENAM, the National Metrology Institute (NMI) of Mexico, The proposed method uses a vision system to align the scale mark of the hydrometer to the surface of the liquid where it is immersed by implementing image processing algorithms. This approach reduces the variability in the apparent mass determination during the hydrostatic weighing in the calibration process, therefore decreasing the relative uncertainty of calibration. PMID:24284770

  9. Calibration and validation of a model describing complete autotrophic nitrogen removal in a granular SBR system

    DEFF Research Database (Denmark)

    Vangsgaard, Anna Katrine; Mutlu, Ayten Gizem; Gernaey, Krist;

    2013-01-01

    steady-state in the biofilm system. For oxygen mass transfer coefficient (kLa) estimation, long-term data, removal efficiencies, and the stoichiometry of the reactions were used. For the dynamic calibration a pragmatic model fitting approach was used - in this case an iterative Monte Carlo based...... screening of the parameter space proposed by Sin et al. (2008) - to find the best fit of the model to dynamic data. Finally, the calibrated model was validated with an independent data set. CONCLUSION: The presented calibration procedure is the first customized procedure for this type of system and is...

  10. A Laser Frequency Comb System for Absolute Calibration of the VTT Echelle Spectrograph

    OpenAIRE

    Doerr, H. -P.; T Steinmetz; Holzwarth, R.; Schmidt, T. Kentischer und W.

    2012-01-01

    A wavelength calibration system based on a laser frequency comb (LFC) was developed in a co-operation between the Kiepenheuer-Institut f\\"ur Sonnenphysik, Freiburg, Germany and the Max-Planck-Institut f\\"ur Quantenoptik, Garching, Germany for permanent installation at the German Vacuum Tower Telescope (VTT) on Tenerife, Canary Islands. The system was installed successfully in October 2011. By simultaneously recording the spectra from the Sun and the LFC, for each exposure a calibration curve ...

  11. a New Automatic System Calibration of Multi-Cameras and LIDAR Sensors

    Science.gov (United States)

    Hassanein, M.; Moussa, A.; El-Sheimy, N.

    2016-06-01

    In the last few years, multi-cameras and LIDAR systems draw the attention of the mapping community. They have been deployed on different mobile mapping platforms. The different uses of these platforms, especially the UAVs, offered new applications and developments which require fast and accurate results. The successful calibration of such systems is a key factor to achieve accurate results and for the successful processing of the system measurements especially with the different types of measurements provided by the LIDAR and the cameras. The system calibration aims to estimate the geometric relationships between the different system components. A number of applications require the systems be ready for operation in a short time especially for disasters monitoring applications. Also, many of the present system calibration techniques are constrained with the need of special arrangements in labs for the calibration procedures. In this paper, a new technique for calibration of integrated LIDAR and multi-cameras systems is presented. The new proposed technique offers a calibration solution that overcomes the need for special labs for standard calibration procedures. In the proposed technique, 3D reconstruction of automatically detected and matched image points is used to generate a sparse images-driven point cloud then, a registration between the LIDAR generated 3D point cloud and the images-driven 3D point takes place to estimate the geometric relationships between the cameras and the LIDAR.. In the presented technique a simple 3D artificial target is used to simplify the lab requirements for the calibration procedure. The used target is composed of three intersected plates. The choice of such target geometry was to ensure enough conditions for the convergence of registration between the constructed 3D point clouds from the two systems. The achieved results of the proposed approach prove its ability to provide an adequate and fully automated calibration without

  12. A NEW AUTOMATIC SYSTEM CALIBRATION OF MULTI-CAMERAS AND LIDAR SENSORS

    Directory of Open Access Journals (Sweden)

    M. Hassanein

    2016-06-01

    Full Text Available In the last few years, multi-cameras and LIDAR systems draw the attention of the mapping community. They have been deployed on different mobile mapping platforms. The different uses of these platforms, especially the UAVs, offered new applications and developments which require fast and accurate results. The successful calibration of such systems is a key factor to achieve accurate results and for the successful processing of the system measurements especially with the different types of measurements provided by the LIDAR and the cameras. The system calibration aims to estimate the geometric relationships between the different system components. A number of applications require the systems be ready for operation in a short time especially for disasters monitoring applications. Also, many of the present system calibration techniques are constrained with the need of special arrangements in labs for the calibration procedures. In this paper, a new technique for calibration of integrated LIDAR and multi-cameras systems is presented. The new proposed technique offers a calibration solution that overcomes the need for special labs for standard calibration procedures. In the proposed technique, 3D reconstruction of automatically detected and matched image points is used to generate a sparse images-driven point cloud then, a registration between the LIDAR generated 3D point cloud and the images-driven 3D point takes place to estimate the geometric relationships between the cameras and the LIDAR.. In the presented technique a simple 3D artificial target is used to simplify the lab requirements for the calibration procedure. The used target is composed of three intersected plates. The choice of such target geometry was to ensure enough conditions for the convergence of registration between the constructed 3D point clouds from the two systems. The achieved results of the proposed approach prove its ability to provide an adequate and fully automated

  13. Design and Realization of a Radon Gas Calibration System

    International Nuclear Information System (INIS)

    Our project consists on the automatization of a Radon calibration room. The first step was the development of several electronic cards collecting outside data coming to our device (pressure and temperature). Using ISIS software, we have designed these electronic cards: pressure, temperature, power supply, PIC interface and control card. In the second part, we have programmed the PIC 16F877 using the PCW compiler to display data on an LCD screen and sent them through the RS232 serial to the hyper-terminal and to control the motor and the fan. The last part aims to develop an interface using LabVIEW to command our device.

  14. Distributed UHV system for the folded tandem ion accelerator facility at BARC

    International Nuclear Information System (INIS)

    The 6 MV Folded Tandem Ion Accelerator (FOTIA) Facility at the Nuclear Physics Division, BARC is operational and accelerated beams of both light and heavy ions are being used extensively for basic and applied research. An average vacuum of the order of 10-8-10-9 Torr is maintained for maximum beam transmission and minimum beam energy spreads. The FOTIA vacuum system comprises of about 55 meter long, 100 mm diameter beam lines including various diagnostic devices, two accelerating tubes and four narrow vacuum chambers. The cross sections of the vacuum chambers are 14mm x 24mm for 180 deg., 38mm x 60mm and 19 x 44 mm for the and 70 deg. and 90 deg. bending magnets and Switching chambers respectively. All the beam line components are UHV compatible, fabricated from stainless steel 304L grade material fitted with metal gaskets. The total volume ∼5.8 x 105 cm3 and surface area of 4.6 x 104 cm2, interspersed with total 18 pumping stations. The accelerating tubes are subjected to very high voltage gradient, 20.4 kV/cm, which requires a hydrocarbon free and clean vacuum for smooth operation of the accelerator. Vacuum interlocks are provided to various devices for safe operation of the accelerator. Specially designed sputter ion pumps for higher environmental pressure of 8 atmospheres are used to pump the accelerating tubes and the vacuum chamber for the 180 deg. bending magnet. Fast acting valves are provided for isolating main accelerator against accidental air rush from rest of the beam lines. All the vacuum readings are displayed locally and are also available remotely through computer interface to the Control Room. Vacuum system details are described in this paper

  15. Embedded calibration system for the DIII-D Langmuir probe analog fiber optic linksa)

    Science.gov (United States)

    Watkins, J. G.; Rajpal, R.; Mandaliya, H.; Watkins, M.; Boivin, R. L.

    2012-10-01

    This paper describes a generally applicable technique for simultaneously measuring offset and gain of 64 analog fiber optic data links used for the DIII-D fixed Langmuir probes by embedding a reference voltage waveform in the optical transmitted signal before every tokamak shot. The calibrated data channels allow calibration of the power supply control fiber optic links as well. The array of fiber optic links and the embedded calibration system described here makes possible the use of superior modern data acquisition electronics in the control room.

  16. Embedded calibration system for the DIII-D Langmuir probe analog fiber optic links

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, J. G. [Sandia National Laboratories, Livermore, California (United States); Rajpal, R.; Mandaliya, H. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat (India); Watkins, M.; Boivin, R. L. [General Atomics, San Diego, California (United States)

    2012-10-15

    This paper describes a generally applicable technique for simultaneously measuring offset and gain of 64 analog fiber optic data links used for the DIII-D fixed Langmuir probes by embedding a reference voltage waveform in the optical transmitted signal before every tokamak shot. The calibrated data channels allow calibration of the power supply control fiber optic links as well. The array of fiber optic links and the embedded calibration system described here makes possible the use of superior modern data acquisition electronics in the control room.

  17. IFIN-HH ionization chamber calibration and its validation; electrometric system improvement

    Energy Technology Data Exchange (ETDEWEB)

    Sahagia, M., E-mail: msahagia@nipne.r [' Horia Hulubei' National Institute of R and D for Physics and Nuclear Engineering, IFIN-HH, P.O. Box MG-6, Bucharest, RO-77125 (Romania); Waetjen, A.C.; Luca, A.; Ivan, C. [' Horia Hulubei' National Institute of R and D for Physics and Nuclear Engineering, IFIN-HH, P.O. Box MG-6, Bucharest, RO-77125 (Romania)

    2010-07-15

    The paper presents the results obtained in the calibration of the CENTRONIC IG12/20A ionization chamber for 18 gamma ray emitters, and its improvement with a Keithley 6517A electrometer. The calibration figures were determined either directly in pA MBq{sup -1} units, or calculated from old units, by using the system capacity value. The calibration figures, determined with RML's standards, are compared with those deduced from the KCRV or the mean of the comparisons, and the values determined at PTB-Germany.

  18. IFIN-HH ionization chamber calibration and its validation; electrometric system improvement.

    Science.gov (United States)

    Sahagia, M; Wätjen, A C; Luca, A; Ivan, C

    2010-01-01

    The paper presents the results obtained in the calibration of the CENTRONIC IG12/20A ionization chamber for 18 gamma ray emitters, and its improvement with a Keithley 6517A electrometer. The calibration figures were determined either directly in pA MBq(-1) units, or calculated from old units, by using the system capacity value. The calibration figures, determined with RML's standards, are compared with those deduced from the KCRV or the mean of the comparisons, and the values determined at PTB-Germany.

  19. Easy calibration method of vision system for in-situ measurement of strain of thin films

    Institute of Scientific and Technical Information of China (English)

    Jun-Hyub PARK; Dong-Joong KANG; Myung-Soo SHIN; Sung-Jo LIM; Son-Cheol YU; Kwang-Soo LEE; Jong-Eun HA; Sung-Hoon CHOA

    2009-01-01

    An easy calibration method was presented for in-situ measurement of displacement in the order of nanometer during micro-tensile test for thin films by using CCD camera as a sensing device. The calibration of the sensing camera in the system is a central element part to measure displacement in the order of nanometer using images taken with the camera. This was accomplished by modeling the optical projection through the camera lens and relative locations between the object and camera in 3D space. A set of known 3D points on a plane where the film is located on is projected to an image plane as input data. These points, known as a calibration points, are then used to estimate the projection parameters of the camera. In the measurement system of the micro-scale by CCD camera, the calibration data acquisition and one-to-one matching steps between the image and 3D planes need precise data extraction procedures and repetitive user's operation to calibrate the measuring devices. The lack of the robust image feature extraction and easy matching prevent the practical use of these methods. A data selection method was proposed to overcome these limitations and offer an easy and convenient calibration of a vision system that has the CCD camera and the 3D reference plane with calibration marks of circular type on the surface of the plane. The method minimizes the user's intervention such as the fine tuning of illumination system and provides an efficient calibration method of the vision system for in-situ axial displacement measurement of the micro-tensile materials.

  20. Design and calibration of a new high-definition three-dimensional laparoscopic system

    Institute of Scientific and Technical Information of China (English)

    Jia TANG; Li-qiang WANG‡; Bo YUAN; Hong JIANG; Qi-ming ZHU

    2015-01-01

    We present a high-definition (HD) 3D laparoscopic system including a dual channel optical system, two cameras, a camera control unit (CCU), and an HD 3D monitor. This laparoscopic system is capable of outputting dual high-definition videos and providing vivid 3D images. A modified pinhole camera model is used for camera calibration and a new method of depth measurement to improve precision. The average error of depth measurement measured by experiment (about 1.13 mm) was small in proportion to the large range in distance of the system (10–150 mm). The new method is applicable to any calibrated binocular vision system.

  1. Radiometric calibration of frame transfer CCD camera with uniform source system

    Science.gov (United States)

    Zhou, Jiankang; Shi, Rongbao; Chen, Yuheng; Zhou, Yuying; Shen, Weimin

    2010-08-01

    This paper presents a radiometric calibration method based on visibility function and uniform source system. The uniform system is mainly comprised of an integrating sphere and a monitoring silicon detector. The current of the silicon detector with a visibility function filter corresponds to the luminance at the exit port of integrating sphere through standard luminance meter transfer. The radiance at the camera entrance pupil is calculated for different solar zenith angles and Earth surface albedos by the MODTRAN atmospheric code. To simplify the calibration process, the radiance at its entrance pupil is integrated by visibility function. The shift smear of the frame transfer CCD is removed by the radiometric calibration and the amending ratio factor is introduced in the retrieving methods. The imaging experiment verifies the reliability of the calibration method and retrieves good quality image.

  2. Performance of a laser frequency comb calibration system with a high-resolution solar echelle spectrograph

    Science.gov (United States)

    Doerr, H.-P.; Kentischer, T. J.; Steinmetz, T.; Probst, R. A.; Franz, M.; Holzwarth, R.; Udem, Th.; Hänsch, T. W.; Schmidt, W.

    2012-09-01

    Laser frequency combs (LFC) provide a direct link between the radio frequency (RF) and the optical frequency regime. The comb-like spectrum of an LFC is formed by exact equidistant laser modes, whose absolute optical frequencies are controlled by RF-references such as atomic clocks or GPS receivers. While nowadays LFCs are routinely used in metrological and spectroscopic fields, their application in astronomy was delayed until recently when systems became available with a mode spacing and wavelength coverage suitable for calibration of astronomical spectrographs. We developed a LFC based calibration system for the high-resolution echelle spectrograph at the German Vacuum Tower Telescope (VTT), located at the Teide observatory, Tenerife, Canary Islands. To characterize the calibration performance of the instrument, we use an all-fiber setup where sunlight and calibration light are fed to the spectrograph by the same single-mode fiber, eliminating systematic effects related to variable grating illumination.

  3. Upgrade of the Laser calibration system for the ATLAS hadronic calorimeter TileCal

    Science.gov (United States)

    van Woerden, Marius Cornelis

    2016-07-01

    We present in this contribution the new system for Laser calibration of the ATLAS hadronic calorimeter TileCal. The Laser system is a part of the three stage calibration apparatus designed to compute the calibration factors of the individual cells of TileCal. The Laser system is mainly used to correct for short term drifts of the readout of the individual cells. A sub-percent accuracy in the control of the calibration factors is required. To achieve this goal in the LHC Run2 conditions, a new Laser system was designed. The architecture of the system is described with details on the new optical line used to distribute Laser pulses in each individual detector module and on the new electronics used to drive the Laser, to read out optical monitors and to interface the system with the ATLAS readout, trigger and slow control. The LaserII system has been fully integrated into the framework used for measuring calibration factors and for monitoring data quality. First results on the Laser system performances studied are presented.

  4. Micromorph tandem solar cells: optimization of the microcrystalline silicon bottom cell in a single chamber system

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiao-Dan; Zheng Xin-Xia; Xu Sheng-Zhi; Lin Quan; Wei Chang-Chun; Sun Jian; Geng Xin-Hua; Zhao Ying

    2011-01-01

    We report on the development of single chamber deposition of microcrystalline and micromorph tandem solar cells directly onto low-cost glass substrates.The cells have pin single-junction or pin/pin double-junction structures on glass substrates coated with a transparent conductive oxide layer such as SnO2 or ZnO.By controlling boron and phosphorus contaminations,a single-junction microcrystalline silicon cell with a conversion efficiency of 7.47% is achieved with an i-layer thickness of 1.2 μm.In tandem devices,by thickness optimization of the microcrystalline silicon bottom solar cell,we obtained an initial conversion efficiency of 9.91% with an aluminum (Al) back reflector without a dielectric layer.In order to enhance the performance of the tandem solar cells,an improved light trapping structure with a ZnO/Al back reflector is used.As a result,a tandem solar cell with 11.04% of initial conversion efficiency has been obtained.

  5. Micromorph tandem solar cells: optimization of the microcrystalline silicon bottom cell in a single chamber system

    Science.gov (United States)

    Zhang, Xiao-Dan; Zheng, Xin-Xia; Xu, Sheng-Zhi; Lin, Quan; Wei, Chang-Chun; Sun, Jian; Geng, Xin-Hua; Zhao, Ying

    2011-10-01

    We report on the development of single chamber deposition of microcrystalline and micromorph tandem solar cells directly onto low-cost glass substrates. The cells have pin single-junction or pin/pin double-junction structures on glass substrates coated with a transparent conductive oxide layer such as SnO2 or ZnO. By controlling boron and phosphorus contaminations, a single-junction microcrystalline silicon cell with a conversion efficiency of 7.47% is achieved with an i-layer thickness of 1.2 μm. In tandem devices, by thickness optimization of the microcrystalline silicon bottom solar cell, we obtained an initial conversion efficiency of 9.91% with an aluminum (Al) back reflector without a dielectric layer. In order to enhance the performance of the tandem solar cells, an improved light trapping structure with a ZnO/Al back reflector is used. As a result, a tandem solar cell with 11.04% of initial conversion efficiency has been obtained.

  6. One-Step and Two-Step Calibration of a Portable Panoramic Image Mapping System

    Science.gov (United States)

    Wang, P.-C.; Tsai, P.-C.; Chen, Y.-C.; Tseng, Y.-H.

    2012-07-01

    A Portable Panoramic Image Mapping System (PPIMS) is proposed for rapid acquisition of three-dimensional spatial information. By considering the convenience of use, cost, weight of equipment, precision, and power supply, the designed PPIMS is equipped with 6 circularly arranged cameras to capture panoramic images and a GPS receiver for positioning. The motivation for this design is to develop a hand-held Mobile Mapping System (MMS) for some difficult accessing areas by vehicle MMS, such as rugged terrains, forest areas, heavily damaged disaster areas, and crowed places etc. This PPIMS is in fact a GPS assisted close-range photogrammetric system. Compared with the traditional close-range photogrammetry, PPIMS can reduce the need of ground control points significantly. Under the condition of knowing the relative geometric relationships of the equipped sensors, the elements of exterior orientation of each captured image can be solved. However, the procedure of a system calibration should be done accurately to determine the relative geometric relationships of multi-cameras and the GPS antenna center, before the PPIMS can be applied for geo-referenced mapping. In this paper, both of one-step and two-step calibration procedures for PPIMS are performed to determine the lever-arm offsets and boresight angles among cameras and GPS. The performance of the one-step and two-step calibration is evaluated through the analysis of the experimental results. The comparison between these two calibration procedures was also conducted. The two-step calibration method outperforms the one-step calibration method in terms of calibration accuracy and operation convenience. We expect that the proposed two-step calibration procedure can also be applied to other platform-based MMSs.

  7. Self-calibration method for rotating laser positioning system using interscanning technology and ultrasonic ranging.

    Science.gov (United States)

    Wu, Jun; Yu, Zhijing; Zhuge, Jingchang

    2016-04-01

    A rotating laser positioning system (RLPS) is an efficient measurement method for large-scale metrology. Due to multiple transmitter stations, which consist of a measurement network, the position relationship of these stations must be first calibrated. However, with such auxiliary devices such as a laser tracker, scale bar, and complex calibration process, the traditional calibration methods greatly reduce the measurement efficiency. This paper proposes a self-calibration method for RLPS, which can automatically obtain the position relationship. The method is implemented through interscanning technology by using a calibration bar mounted on the transmitter station. Each bar is composed of three RLPS receivers and one ultrasonic sensor whose coordinates are known in advance. The calibration algorithm is mainly based on multiplane and distance constraints and is introduced in detail through a two-station mathematical model. The repeated experiments demonstrate that the coordinate measurement uncertainty of spatial points by using this method is about 0.1 mm, and the accuracy experiments show that the average coordinate measurement deviation is about 0.3 mm compared with a laser tracker. The accuracy can meet the requirements of most applications, while the calibration efficiency is significantly improved. PMID:27140762

  8. A robust method for online stereo camera self-calibration in unmanned vehicle system

    Science.gov (United States)

    Zhao, Yu; Chihara, Nobuhiro; Guo, Tao; Kimura, Nobutaka

    2014-06-01

    Self-calibration is a fundamental technology used to estimate the relative posture of the cameras for environment recognition in unmanned system. We focused on the issue of recognition accuracy decrease caused by the vibration of platform and conducted this research to achieve on-line self-calibration using feature point's registration and robust estimation of fundamental matrix. Three key factors in this respect are needed to be improved. Firstly, the feature mismatching exists resulting in the decrease of estimation accuracy of relative posture. The second, the conventional estimation method cannot satisfy both the estimation speed and calibration accuracy at the same tame. The third, some system intrinsic noises also lead greatly to the deviation of estimation results. In order to improve the calibration accuracy, estimation speed and system robustness for the practical implementation, we discuss and analyze the algorithms to make improvements on the stereo camera system to achieve on-line self-calibration. Based on the epipolar geometry and 3D images parallax, two geometry constraints are proposed to make the corresponding feature points search performed in a small search-range resulting in the improvement of matching accuracy and searching speed. Then, two conventional estimation algorithms are analyzed and evaluated for estimation accuracy and robustness. The third, Rigorous posture calculation method is proposed with consideration of the relative posture deviation of each separated parts in the stereo camera system. Validation experiments were performed with the stereo camera mounted on the Pen-Tilt Unit for accurate rotation control and the evaluation shows that our proposed method is fast and of high accuracy with high robustness for on-line self-calibration algorithm. Thus, as the main contribution, we proposed methods to solve the on-line self-calibration fast and accurately, envision the possibility for practical implementation on unmanned system as

  9. Bore-Sight Calibration of Multiple Laser Range Finders for Kinematic 3D Laser Scanning Systems

    Directory of Open Access Journals (Sweden)

    Jaehoon Jung

    2015-05-01

    Full Text Available The Simultaneous Localization and Mapping (SLAM technique has been used for autonomous navigation of mobile systems; now, its applications have been extended to 3D data acquisition of indoor environments. In order to reconstruct 3D scenes of indoor space, the kinematic 3D laser scanning system, developed herein, carries three laser range finders (LRFs: one is mounted horizontally for system-position correction and the other two are mounted vertically to collect 3D point-cloud data of the surrounding environment along the system’s trajectory. However, the kinematic laser scanning results can be impaired by errors resulting from sensor misalignment. In the present study, the bore-sight calibration of multiple LRF sensors was performed using a specially designed double-deck calibration facility, which is composed of two half-circle-shaped aluminum frames. Moreover, in order to automatically achieve point-to-point correspondences between a scan point and the target center, a V-shaped target was designed as well. The bore-sight calibration parameters were estimated by a constrained least squares method, which iteratively minimizes the weighted sum of squares of residuals while constraining some highly-correlated parameters. The calibration performance was analyzed by means of a correlation matrix. After calibration, the visual inspection of mapped data and residual calculation confirmed the effectiveness of the proposed calibration approach.

  10. Calibration of a multichannel MEG system based on the signal space separation method.

    Science.gov (United States)

    Chella, F; Zappasodi, F; Marzetti, L; Della Penna, S; Pizzella, V

    2012-08-01

    For an efficient use of multichannel MEG systems, an accurate sensor calibration is extremely important. This includes the knowledge of both channel sensitivities and channel arrangement, which can deviate from original system plans, e.g., because of thermal stresses. In this paper, we propose a new solution to the calibration of a multichannel MEG sensor array based on the signal space separation (SSS) method. It has been shown that an inaccurate knowledge of sensor calibration limits the performances of the SSS method, resulting in a mismatch between the measured neuromagnetic field and its SSS reconstruction. Given a set of known magnetic sources, we show that an objective function, which strongly depends on sensor geometry, can be derived from the principal angle between the measured vector signal and the SSS basis. Hence, the MEG sensor array calibration is carried out by minimizing the objective function through a standard large-scale optimization technique. Details on the magnetic sources and calibration process are presented here. Finally, an application to the calibration of the 153-channel whole-head MEG system installed at the University of Chieti is discussed. PMID:22797687

  11. An efficient calibration method for SQUID measurement system using three orthogonal Helmholtz coils

    Science.gov (United States)

    Hua, Li; Shu-Lin, Zhang; Chao-Xiang, Zhang; Xiang-Yan, Kong; Xiao-Ming, Xie

    2016-06-01

    For a practical superconducting quantum interference device (SQUID) based measurement system, the Tesla/volt coefficient must be accurately calibrated. In this paper, we propose a highly efficient method of calibrating a SQUID magnetometer system using three orthogonal Helmholtz coils. The Tesla/volt coefficient is regarded as the magnitude of a vector pointing to the normal direction of the pickup coil. By applying magnetic fields through a three-dimensional Helmholtz coil, the Tesla/volt coefficient can be directly calculated from magnetometer responses to the three orthogonally applied magnetic fields. Calibration with alternating current (AC) field is normally used for better signal-to-noise ratio in noisy urban environments and the results are compared with the direct current (DC) calibration to avoid possible effects due to eddy current. In our experiment, a calibration relative error of about 6.89 × 10‑4 is obtained, and the error is mainly caused by the non-orthogonality of three axes of the Helmholtz coils. The method does not need precise alignment of the magnetometer inside the Helmholtz coil. It can be used for the multichannel magnetometer system calibration effectively and accurately. Project supported by the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB04020200) and the Shanghai Municipal Science and Technology Commission Project, China (Grant No. 15DZ1940902).

  12. An efficient calibration method for SQUID measurement system using three orthogonal Helmholtz coils

    Science.gov (United States)

    Hua, Li; Shu-Lin, Zhang; Chao-Xiang, Zhang; Xiang-Yan, Kong; Xiao-Ming, Xie

    2016-06-01

    For a practical superconducting quantum interference device (SQUID) based measurement system, the Tesla/volt coefficient must be accurately calibrated. In this paper, we propose a highly efficient method of calibrating a SQUID magnetometer system using three orthogonal Helmholtz coils. The Tesla/volt coefficient is regarded as the magnitude of a vector pointing to the normal direction of the pickup coil. By applying magnetic fields through a three-dimensional Helmholtz coil, the Tesla/volt coefficient can be directly calculated from magnetometer responses to the three orthogonally applied magnetic fields. Calibration with alternating current (AC) field is normally used for better signal-to-noise ratio in noisy urban environments and the results are compared with the direct current (DC) calibration to avoid possible effects due to eddy current. In our experiment, a calibration relative error of about 6.89 × 10-4 is obtained, and the error is mainly caused by the non-orthogonality of three axes of the Helmholtz coils. The method does not need precise alignment of the magnetometer inside the Helmholtz coil. It can be used for the multichannel magnetometer system calibration effectively and accurately. Project supported by the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB04020200) and the Shanghai Municipal Science and Technology Commission Project, China (Grant No. 15DZ1940902).

  13. Study of the performance of stereoscopic panomorph systems calibrated with traditional pinhole model

    Science.gov (United States)

    Poulin-Girard, Anne-Sophie; Thibault, Simon; Laurendeau, Denis

    2016-06-01

    With their large field of view, anamorphosis, and areas of enhanced magnification, panomorph lenses are an interesting choice for navigation systems for mobile robotics in which knowledge of the surroundings is mandatory. However, panomorph lenses special characteristics can be challenging during the calibration process. This study focuses on the calibration of two panomorph stereoscopic systems with a model and technique developed for narrow-angle lenses, the "Camera Calibration Toolbox for MATLAB." In order to assess the performance of the systems, the mean reprojection error (MRE) related to the calibration and the reconstruction error of control points of an object of interest at various locations in the field of view are used. The calibrations were successful and exhibit MREs of less than one pixel in all cases. However, some poorly reconstructed control points illustrate that an acceptable MRE guarantees neither the quality of 3-D reconstruction nor its uniformity in the field of view. In addition, the nonuniformity in the 3-D reconstruction quality indicates that panomorph lenses require a more accurate estimation of the principal point (center of distortion) coordinates to improve the calibration and therefore the 3-D reconstruction.

  14. Automatic pneumatic source-control system for positioning gamma and neutron calibration sources

    International Nuclear Information System (INIS)

    A microcomputer-based source-control system was developed to move gamma and neutron calibration sources into position for sample irradiation. In addition to monitoring interlocks and system status, the computer calculates for gamma sources the time required for a requested exposure at a specified distance. All system use data is stored, and monthly reports are generated

  15. Improving Photometric Calibration of Meteor Video Camera Systems

    Science.gov (United States)

    Ehlert, Steven; Kingery, Aaron; Suggs, Robert

    2016-01-01

    We present the results of new calibration tests performed by the NASA Meteoroid Environment Oce (MEO) designed to help quantify and minimize systematic uncertainties in meteor photometry from video camera observations. These systematic uncertainties can be categorized by two main sources: an imperfect understanding of the linearity correction for the MEO's Watec 902H2 Ultimate video cameras and uncertainties in meteor magnitudes arising from transformations between the Watec camera's Sony EX-View HAD bandpass and the bandpasses used to determine reference star magnitudes. To address the rst point, we have measured the linearity response of the MEO's standard meteor video cameras using two independent laboratory tests on eight cameras. Our empirically determined linearity correction is critical for performing accurate photometry at low camera intensity levels. With regards to the second point, we have calculated synthetic magnitudes in the EX bandpass for reference stars. These synthetic magnitudes enable direct calculations of the meteor's photometric ux within the camera band-pass without requiring any assumptions of its spectral energy distribution. Systematic uncertainties in the synthetic magnitudes of individual reference stars are estimated at 0:20 mag, and are limited by the available spectral information in the reference catalogs. These two improvements allow for zero-points accurate to 0:05 ?? 0:10 mag in both ltered and un ltered camera observations with no evidence for lingering systematics.

  16. Transponder-aided joint calibration and synchronization compensation for distributed radar systems.

    Directory of Open Access Journals (Sweden)

    Wen-Qin Wang

    Full Text Available High-precision radiometric calibration and synchronization compensation must be provided for distributed radar system due to separate transmitters and receivers. This paper proposes a transponder-aided joint radiometric calibration, motion compensation and synchronization for distributed radar remote sensing. As the transponder signal can be separated from the normal radar returns, it is used to calibrate the distributed radar for radiometry. Meanwhile, the distributed radar motion compensation and synchronization compensation algorithms are presented by utilizing the transponder signals. This method requires no hardware modifications to both the normal radar transmitter and receiver and no change to the operating pulse repetition frequency (PRF. The distributed radar radiometric calibration and synchronization compensation require only one transponder, but the motion compensation requires six transponders because there are six independent variables in the distributed radar geometry. Furthermore, a maximum likelihood method is used to estimate the transponder signal parameters. The proposed methods are verified by simulation results.

  17. Transponder-aided joint calibration and synchronization compensation for distributed radar systems.

    Science.gov (United States)

    Wang, Wen-Qin

    2015-01-01

    High-precision radiometric calibration and synchronization compensation must be provided for distributed radar system due to separate transmitters and receivers. This paper proposes a transponder-aided joint radiometric calibration, motion compensation and synchronization for distributed radar remote sensing. As the transponder signal can be separated from the normal radar returns, it is used to calibrate the distributed radar for radiometry. Meanwhile, the distributed radar motion compensation and synchronization compensation algorithms are presented by utilizing the transponder signals. This method requires no hardware modifications to both the normal radar transmitter and receiver and no change to the operating pulse repetition frequency (PRF). The distributed radar radiometric calibration and synchronization compensation require only one transponder, but the motion compensation requires six transponders because there are six independent variables in the distributed radar geometry. Furthermore, a maximum likelihood method is used to estimate the transponder signal parameters. The proposed methods are verified by simulation results. PMID:25794158

  18. Online drift velocity calibration with the laser system of the ALICE-TPC

    International Nuclear Information System (INIS)

    The ALICE Time Projection Chamber (TPC) is the main tracking detector of ALICE which was designed to perform well at multiplicities of up to 20000 charged primary and secondary tracks emerging from Pb-Pb collisions. For a precise reconstruction of particle tracks in the TPC, the calibration of the drift velocity, which provides time information and thus the z position of the traversing particles, is essential. In this presentation an online method for the calibration of the drift velocity is presented, using the TPC laser system. The resulting time dependent drift velocity correction parameters are entered into a database and provide start values for the offline reconstruction process of ALICE. Even though no tracking information is used, the online drift velocity calibration is in agreement with the full offline calibration including tracking on the level of 2 x 10-4.

  19. Transponder-aided joint calibration and synchronization compensation for distributed radar systems.

    Science.gov (United States)

    Wang, Wen-Qin

    2015-01-01

    High-precision radiometric calibration and synchronization compensation must be provided for distributed radar system due to separate transmitters and receivers. This paper proposes a transponder-aided joint radiometric calibration, motion compensation and synchronization for distributed radar remote sensing. As the transponder signal can be separated from the normal radar returns, it is used to calibrate the distributed radar for radiometry. Meanwhile, the distributed radar motion compensation and synchronization compensation algorithms are presented by utilizing the transponder signals. This method requires no hardware modifications to both the normal radar transmitter and receiver and no change to the operating pulse repetition frequency (PRF). The distributed radar radiometric calibration and synchronization compensation require only one transponder, but the motion compensation requires six transponders because there are six independent variables in the distributed radar geometry. Furthermore, a maximum likelihood method is used to estimate the transponder signal parameters. The proposed methods are verified by simulation results.

  20. Optical system error analysis and calibration method of high-accuracy star trackers.

    Science.gov (United States)

    Sun, Ting; Xing, Fei; You, Zheng

    2013-01-01

    The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers. PMID:23567527

  1. Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

    Directory of Open Access Journals (Sweden)

    Zheng You

    2013-04-01

    Full Text Available The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

  2. A Flexile and High Precision Calibration Method for Binocular Structured Light Scanning System

    Directory of Open Access Journals (Sweden)

    Jianying Yuan

    2014-01-01

    Full Text Available 3D (three-dimensional structured light scanning system is widely used in the field of reverse engineering, quality inspection, and so forth. Camera calibration is the key for scanning precision. Currently, 2D (two-dimensional or 3D fine processed calibration reference object is usually applied for high calibration precision, which is difficult to operate and the cost is high. In this paper, a novel calibration method is proposed with a scale bar and some artificial coded targets placed randomly in the measuring volume. The principle of the proposed method is based on hierarchical self-calibration and bundle adjustment. We get initial intrinsic parameters from images. Initial extrinsic parameters in projective space are estimated with the method of factorization and then upgraded to Euclidean space with orthogonality of rotation matrix and rank 3 of the absolute quadric as constraint. Last, all camera parameters are refined through bundle adjustment. Real experiments show that the proposed method is robust, and has the same precision level as the result using delicate artificial reference object, but the hardware cost is very low compared with the current calibration method used in 3D structured light scanning system.

  3. A Visual Servoing-Based Method for ProCam Systems Calibration

    Science.gov (United States)

    Berry, Francois; Aider, Omar Ait; Mosnier, Jeremie

    2013-01-01

    Projector-camera systems are currently used in a wide field of applications, such as 3D reconstruction and augmented reality, and can provide accurate measurements, depending on the configuration and calibration. Frequently, the calibration task is divided into two steps: camera calibration followed by projector calibration. The latter still poses certain problems that are not easy to solve, such as the difficulty in obtaining a set of 2D–3D points to compute the projection matrix between the projector and the world. Existing methods are either not sufficiently accurate or not flexible. We propose an easy and automatic method to calibrate such systems that consists in projecting a calibration pattern and superimposing it automatically on a known printed pattern. The projected pattern is provided by a virtual camera observing a virtual pattern in an OpenGL model. The projector displays what the virtual camera visualizes. Thus, the projected pattern can be controlled and superimposed on the printed one with the aid of visual servoing. Our experimental results compare favorably with those of other methods considering both usability and accuracy. PMID:24084121

  4. Automatic calibration system for analog instruments based on DSP and CCD sensor

    Science.gov (United States)

    Lan, Jinhui; Wei, Xiangqin; Bai, Zhenlong

    2008-12-01

    Currently, the calibration work of analog measurement instruments is mainly completed by manual and there are many problems waiting for being solved. In this paper, an automatic calibration system (ACS) based on Digital Signal Processor (DSP) and Charge Coupled Device (CCD) sensor is developed and a real-time calibration algorithm is presented. In the ACS, TI DM643 DSP processes the data received by CCD sensor and the outcome is displayed on Liquid Crystal Display (LCD) screen. For the algorithm, pointer region is firstly extracted for improving calibration speed. And then a math model of the pointer is built to thin the pointer and determine the instrument's reading. Through numbers of experiments, the time of once reading is no more than 20 milliseconds while it needs several seconds if it is done manually. At the same time, the error of the instrument's reading satisfies the request of the instruments. It is proven that the automatic calibration system can effectively accomplish the calibration work of the analog measurement instruments.

  5. A simple recirculating flow system for the calibration of polar organic chemical integrative samplers (POCIS): effect of flow rate on different water pollutants.

    Science.gov (United States)

    Di Carro, Marina; Bono, Luca; Magi, Emanuele

    2014-03-01

    A calibration system for POCIS was developed and used to calculate the sampling rates of eight analytes belonging to pesticides, non-steroidal anti-inflammatory drugs and perfluorinated compounds: atrazine, propazine, terbutylazine, diclofenac, ibuprofen, ketoprofen, perfluorooctanoic acid and perfluorooctanesulfonate. Experiments with a linear velocity of 2.0, 5.1, 10.2 and 15.3 cm/s were carried out for 96 h using two different analyte concentrations. POCIS extracts were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), using multiple reaction monitoring to maximize sensitivity. Results highlighted that the calculated sampling rates are rather constant at the considered concentrations and flow rates. Obtained values of sampling rates were then employed to calculate Time-Weighted Average concentration of the analytes in river and drinking waters.

  6. Aspects of the optical system relevant for the KM3NeT timing calibration

    Directory of Open Access Journals (Sweden)

    Kieft Gerard

    2016-01-01

    Full Text Available KM3NeT is a future research infrastructure in the Mediterranean Sea housing the large Cherenkov telescope arrays of optical modules for neutrino detection. The detector control and data transmission system is based on fibre optical technology. For timing calibration of the detector signals the optical system is used to send and fan-out an onshore clock signal, derived from a GPS receiver, to all optical modules in the deep sea. The optical modules use this clock signal to time stamp the light pulses detected by the photomultipliers inside the modules. The delay time between the GPS clock on shore and the clock in each optical module is measured with sub-nanosecond precision using a White Rabbit based timing calibration system. The aspects of the optical system relevant for the timing calibration and the quantification of their effect will be presented.

  7. Study on Calibration System for Electronic Transformers Based on High-Accuracy PCI Card

    Directory of Open Access Journals (Sweden)

    Mingzhu Zhang

    2013-03-01

    Full Text Available With preliminary applying of Electronic Transformer (ET based on IEC 61850 standards in power grid, the calibrations of tested transformers have attracted extensive research attention. This study proposes a novel Calibration System of ET (CSET based on high-accuracy card. Data acquisition of ET and Standard Trans-former (ST is gotten by optic Ethernet and PCI-4462 data acquisition card, respectively. Meanwhile, the synchronized sampling between ET and ST is completed on the optic/electronic pulse signal of PCI synchronization card. The signals processing and human interface are realized by Labview software. The system proposed in the study is feasible for calibrating Electronic Voltage/Current Transformers (EVT/ECT of different voltage classes. System tests show that the precision of the system can get to 0.2°.

  8. Study on Calibration System for Electronic Transformers Based on High-Accuracy PCI Card

    Directory of Open Access Journals (Sweden)

    Mingzhu Zhang

    2013-05-01

    Full Text Available With preliminary applying of Electronic Transformer (ET based on IEC 61850 standards in power grid, the calibration of tested transformers has attracted extensive research attention. This study proposes a novel Calibration System of ET (CSET based on high-accuracy card. Data acquisition of ET and standard trans-former (ST is gotten by optic Ethernet and PCI-4462 data acquisition card, respectively. Meanwhile, the synchronized sampling between ET and ST is completed on the optic/electronic pulse signal of PCI synchronization card. The signals processing and human interface are realized by Lab view software. The system proposed in the study is feasible for calibrating Electronic Voltage/Current Transformers (EVT/ECT of different voltage classes. System tests show that the precision of the system can get to 0.2°.

  9. Dynamic linear calibration method for a wide range neutron flux monitor system in ITER

    International Nuclear Information System (INIS)

    As a key part of the diagnosis system in the International Thermonuclear Experimental Reactor (ITER), the neutron flux monitor (NFM), which measures the neutron intensity of the fusion reaction, is a Counting-Campbelling system with a large dynamic counting range. A dynamic linear calibration method is proposed in this paper to solve the problem of cross-over between the different counting and Campbelling channels, and improve the accuracy of the cross-calibration for long-term operation. The experimental results show that the NFM system with the dynamic linear calibration system can obtain the neutron flux of the fusion reactor in real time and realize the seamless measurement area connection between the two channels. (authors)

  10. Development of an XYZ Digital Camera with Embedded Color Calibration System for Accurate Color Acquisition

    Science.gov (United States)

    Kretkowski, Maciej; Jablonski, Ryszard; Shimodaira, Yoshifumi

    Acquisition of accurate colors is important in the modern era of widespread exchange of electronic multimedia. The variety of device-dependent color spaces causes troubles with accurate color reproduction. In this paper we present the outlines of accomplished digital camera system with device-independent output formed from tristimulus XYZ values. The outstanding accuracy and fidelity of acquired color is achieved in our system by employing an embedded color calibration system based on emissive device generating reference calibration colors with user-defined spectral distribution and chromaticity coordinates. The system was tested by calibrating the camera using 24 reference colors spectrally reproduced from 24 color patches of the Macbeth Chart. The average color difference (CIEDE2000) has been found to be ΔE =0.83, which is an outstanding result compared to commercially available digital cameras.

  11. The Data Acquisition and Calibration System for the ATLAS Semiconductor Tracker

    CERN Document Server

    Abdesselam, A; Barr, A J; Bell, P; Bernabeu, J; Butterworth, J M; Carter, J R; Carter, A A; Charles, E; Clark, A; Colijn, A P; Costa, M J; Dalmau, J M; Demirkoz, B; Dervan, P J; Donega, M; D'Onifrio, M; Escobar, C; Fasching, D; Ferguson, D P S; Ferrari, P; Ferrère, D; Fuster, J; Gallop, B; García, C; González, S; González-Sevilla, S; Goodrick, M J; Gorisek, A; Greenall, A; Grillo, A A; Hessey, N P; Hill, J C; Jackson, J N; Jared, R C; Johannson, P D C; de Jong, P; Joseph, J; Lacasta, C; Lane, J B; Lester, C G; Limper, M; Lindsay, S W; McKay, R L; Magrath, C A; Mangin-Brinet, M; Martí i García, S; Mellado, B; Meyer, W T; Mikulec, B; Minano, M; Mitsou, V A; Moorhead, G; Morrissey, M; Paganis, E; Palmer, M J; Parker, M A; Pernegger, H; Phillips, A; Phillips, P W; Postranecky, M; Robichaud-Véronneau, A; Robinson, D; Roe, S; Sandaker, H; Sciacca, F; Sfyrla, A; Stanecka, E; Stapnes, S; Stradling, A; Tyndel, M; Tricoli, A; Vickey, T; Vossebeld, J H; Warren, M R M; Weidberg, A R; Wells, P S; Wu, S L

    2008-01-01

    The SemiConductor Tracker (SCT) data acquisition (DAQ) system will calibrate, configure, and control the approximately six million front-end channels of the ATLAS silicon strip detector. It will provide a synchronized bunch-crossing clock to the front-end modules, communicate first-level triggers to the front-end chips, and transfer information about hit strips to the ATLAS high-level trigger system. The system has been used extensively for calibration and quality assurance during SCT barrel and endcap assembly and for performance confirmation tests after transport of the barrels and endcaps to CERN. Operating in data-taking mode, the DAQ has recorded nearly twenty million synchronously-triggered events during commissioning tests including almost a million cosmic ray triggered events. In this paper we describe the components of the data acquisition system, discuss its operation in calibration and data-taking modes and present some detector performance results from these tests.

  12. A novel single-step, multipoint calibration method for instrumented Lab-on-Chip systems

    DEFF Research Database (Denmark)

    Pfreundt, Andrea; Patou, François; Zulfiqar, Azeem;

    2014-01-01

    . The pitfalls of PoC system adoption can be addressed early in the system design phase. They require a multidisciplinary design approach supported by systems engineering tools and methods. Considering this, we here present both a model and an implementation of a simple and rapid calibration scheme...... specifically addresses the important interfaces between a novel microfluidic unit to integrate the sensor array and a mobile-device hardware accessory. A multi-point calibration curve is obtained by generating a defined set of reference concentrations from a single input. By consecutively splitting the flow...

  13. 光电综合标校系统光轴平行度标校方法%Optical Parallelism Calibration Method of Photoelectric Integrated Calibration System

    Institute of Scientific and Technical Information of China (English)

    郑均杰; 张镭; 李杰然

    2011-01-01

    针对光电综合标校系统的功能组成及标校原理,提出了标校靶标的设计及标校方法,并利用感光相纸对激光光斑进行聚焦采集,实现了对电视/红外/激光三者光轴一致性的标校,检测结果验证了该标校靶标及标校方法的可行性和有效性。%Aiming at the function component and calibration principle of photoelectric integrated calibration system,this paper presents the design and calibration method of calibration drone,and realizes the calibration to the axes consistency of television,infrared and laser by using the photographic papers to focus and collect laser spots.The detection result proves the feasibility and usefulness of the calibration drone and the calibration method.

  14. Calibration method for a vision guiding-based laser-tracking measurement system

    Science.gov (United States)

    Shao, Mingwei; Wei, Zhenzhong; Hu, Mengjie; Zhang, Guangjun

    2015-08-01

    Laser-tracking measurement systems (laser trackers) based on a vision-guiding device are widely used in industrial fields, and their calibration is important. As conventional methods typically have many disadvantages, such as difficult machining of the target and overdependence on the retroreflector, a novel calibration method is presented in this paper. The retroreflector, which is necessary in the normal calibration method, is unnecessary in our approach. As the laser beam is linear, points on the beam can be obtained with the help of a normal planar target. In this way, we can determine the function of a laser beam under the camera coordinate system, while its corresponding function under the laser-tracker coordinate system can be obtained from the encoder of the laser tracker. Clearly, when several groups of functions are confirmed, the rotation matrix can be solved from the direction vectors of the laser beams in different coordinate systems. As the intersection of the laser beams is the origin of the laser-tracker coordinate system, the translation matrix can also be determined. Our proposed method not only achieves the calibration of a single laser-tracking measurement system but also provides a reference for the calibration of a multistation system. Simulations to evaluate the effects of some critical factors were conducted. These simulations show the robustness and accuracy of our method. In real experiments, the root mean square error of the calibration result reached 1.46 mm within a range of 10 m, even though the vision-guiding device focuses on a point approximately 5 m away from the origin of its coordinate system, with a field of view of approximately 200 mm  ×  200 mm.

  15. Calibration method for a vision guiding-based laser-tracking measurement system

    International Nuclear Information System (INIS)

    Laser-tracking measurement systems (laser trackers) based on a vision-guiding device are widely used in industrial fields, and their calibration is important. As conventional methods typically have many disadvantages, such as difficult machining of the target and overdependence on the retroreflector, a novel calibration method is presented in this paper. The retroreflector, which is necessary in the normal calibration method, is unnecessary in our approach. As the laser beam is linear, points on the beam can be obtained with the help of a normal planar target. In this way, we can determine the function of a laser beam under the camera coordinate system, while its corresponding function under the laser-tracker coordinate system can be obtained from the encoder of the laser tracker. Clearly, when several groups of functions are confirmed, the rotation matrix can be solved from the direction vectors of the laser beams in different coordinate systems. As the intersection of the laser beams is the origin of the laser-tracker coordinate system, the translation matrix can also be determined. Our proposed method not only achieves the calibration of a single laser-tracking measurement system but also provides a reference for the calibration of a multistation system. Simulations to evaluate the effects of some critical factors were conducted. These simulations show the robustness and accuracy of our method. In real experiments, the root mean square error of the calibration result reached 1.46 mm within a range of 10 m, even though the vision-guiding device focuses on a point approximately 5 m away from the origin of its coordinate system, with a field of view of approximately 200 mm  ×  200 mm. (paper)

  16. Efficiency of tandem solar cell systems as function of temperature and solar energy concentration ratio

    Science.gov (United States)

    Gokcen, N. A.; Loferski, J. J.

    1979-01-01

    The results of a comprehensive theoretical analysis of tandem photovoltaic solar cells as a function of temperature and solar concentration ratio are presented. The overall efficiencies of tandem cell stacks consisting of as many as 24 cells having gaps in the 0.7 to 3.6 eV range were calculated for temperatures of 200, 300, 400, and 500 K and for illumination by an AMO solar spectrum having concentration ratios of 1, 100, 500, and 1000 suns. For ideal diodes (A = B = 1), the calculations show that the optimized overall efficiency has a limiting value eta sub opt of approximately 70 percent for T = 200 K and C = 1000; for T = 300 K and C = 1000, this limiting efficiency approaches 60 percent.

  17. A laser diode based system for calibration of fast time-of-flight detectors

    Science.gov (United States)

    Bertoni, R.; Bonesini, M.; de Bari, A.; Rossella, M.

    2016-05-01

    A system based on commercially available items, such as a laser diode, emitting in the visible range ~ 400 nm, and multimode fiber patches, fused fiber splitters and optical switches may be assembled, for time calibration of multi-channels time-of-flight (TOF) detectors with photomultipliers' (PMTs') readout. As available laser diode sources have unfortunately limited peak power, the main experimental problem is the tight light power budget of such a system. In addition, while the technology for fused fiber splitters is common in the Telecom wavelength range (λ ~ 850, 1300–1500 nm), it is not easily available in the visible one. Therefore, extensive laboratory tests had to be done on purpose, to qualify the used optical components, and a full scale timing calibration prototype was built. Obtained results show that with such a system, a calibration resolution (σ) in the range 20–30 ps may be within reach. Therefore, fast multi-channels TOF detectors, with timing resolutions in the range 50–100 ps, may be easily calibrated in time. Results on tested optical components may be of interest also for time calibration of different light detection systems based on PMTs, as the ones used for detection of the vacuum ultraviolet scintillation light emitted by ionizing particles in large LAr TPCs.

  18. Strain-gage balance calibration of a magnetic suspension and balance system

    Science.gov (United States)

    Roberts, Paul W.; Tcheng, Ping

    1987-01-01

    A load calibration of the NASA 13-in magnetic suspension and balance system (MSBS) is described. The calibration procedure was originally intended to establish the empirical relationship between the coil currents and the external loads (forces and moments) applied to a magnetically suspended calibrator. However, it was discovered that the performance of a strain-gage balance is not affected when subjected to the magnetic environment of the MSBS. The use of strain-gage balances greatly reduces the effort required to perform a current-vs.-load calibration as external loads can be directly inferred from the balance outputs while a calibrator is suspended in MSBS. It is conceivable that in the future such a calibration could become unnecessary, since an even more important application for the use of a strain-gage balance in MSBS environment is the acquisition of precision aerodynamic force and moment data by telemetering the balance outputs from a suspended model/core/balance during wind tunnel tests.

  19. Strain-gage balance calibration of a magnetic suspension and balance system

    Science.gov (United States)

    Roberts, Paul W.; Tcheng, Ping

    A load calibration of the NASA 13-in magnetic suspension and balance system (MSBS) is described. The calibration procedure was originally intended to establish the empirical relationship between the coil currents and the external loads (forces and moments) applied to a magnetically suspended calibrator. However, it was discovered that the performance of a strain-gage balance is not affected when subjected to the magnetic environment of the MSBS. The use of strain-gage balances greatly reduces the effort required to perform a current-vs.-load calibration as external loads can be directly inferred from the balance outputs while a calibrator is suspended in MSBS. It is conceivable that in the future such a calibration could become unnecessary, since an even more important application for the use of a strain-gage balance in MSBS environment is the acquisition of precision aerodynamic force and moment data by telemetering the balance outputs from a suspended model/core/balance during wind tunnel tests.

  20. IRFM Temperature Calibrations for the Vilnius, Geneva, RI(C) and DDO Photometric Systems

    CERN Document Server

    Melendez, J; Melendez, Jorge; Ramirez, Ivan

    2003-01-01

    We have used the infrared flux method (IRFM) temperatures of a large sample of late type dwarfs given by Alonso et al. (1996a) to calibrate empirically the relations Teff = f (colour, [Fe/H]) for the Vilnius, Geneva, RI(C) and DDO photometric systems. The resulting temperature scale and intrinsic colour-colour diagrams for these systems are also obtained. From this scale, the solar colours are derived and compared with those of the solar twin 18 Sco. Since our work is based on the same Teff and [Fe/H] values used by Alonso et al. (1996b) to calibrate other colours, we now have an homogeneous calibration for a large set of photometric systems.

  1. The LED and fiber based calibration system for the photomultiplier array of SNO+

    International Nuclear Information System (INIS)

    A new external LED/fiber light injection calibration system was designed for the calibration and monitoring of the photomultiplier array of the SNO+ experiment at SNOLAB. The goal of the calibration system is to allow an accurate and regular measurement of the photomultiplier array's performance, while minimizing the risk of radioactivity ingress. The choice in SNO+ was to use a set of optical fiber cables to convey into the detector the light pulses produced by external LEDs. The quality control was carried out using a modified test bench that was used in QC of optical fibers for TileCal/ATLAS. The optical fibers were characterized for transmission, timing and angular dispersions. This article describes the setups used for the characterization and quality control of the system based on LEDs and optical fibers and their results

  2. Radioactive source control and electronics for the ATLAS tile calorimeter cesium calibration system

    CERN Document Server

    Shalanda, N A; Kopikov, S; Shalimov, A; Soldatov, M; Solodkov, A; Starchenko, E A

    2003-01-01

    A system using a radioactive /sup 137/Cs source to calibrate and monitor the Hadron Calorimeter (TileCal) of the ATLAS experiment at the LHC is described. The system includes a set of sensors to monitor the position of the source which moves via hydraulic propulsion. The design of the sensors, the corresponding electronic modules and their performance are detailed. (6 refs).

  3. A new optical system for the determination of deformations and strains: calibration characteristics and experimental results.

    Science.gov (United States)

    Derwin, K A; Soslowsky, L J; Green, W D; Elder, S H

    1994-10-01

    Many types of optical strain measurement systems have been used for the determination of deformations and strains in soft biological tissues. The purpose of this investigation is to report a new optical strain measurement system developed in our laboratory which offers distinct advantages over systems developed in the past. Our optical strain system has demonstrated excellent performance in calibration and experimental tests. Calibration tests illustrate the system's accuracy to 0.05% strain at 3.52% strain and 0.18% strain at 11.74% strain. Further, this system can measure strains to within 2% measurement error for strains in a 0-11.74% range when 100 microns increments of motion are used for calibration. The resolution of our system appears to be at least as good as the linear micrometer (2 microns) used as a calibrating standard. Errors in strain measurement due to whole specimen rotation or translation are quantified. Rotations about an in-plane axis perpendicular to the direction of strain and translations in/out of the plane of focus result in the largest sources of error. Finally, in an in vitro biomechanical study of the rabbit Achilles tendon, experimental failure strains are 4.3 +/- 0.9% using this system. PMID:7962015

  4. Modelling and calibration of the laser beam-scanning triangulation measurement system

    NARCIS (Netherlands)

    Wang, Guoyu; Zheng, Bing; Li, Xin; Houkes, Z.; Regtien, P.P.L.

    2002-01-01

    We present an approach of modelling and calibration of an active laser beam-scanning triangulation measurement system. The system works with the pattern of two-dimensional beam-scanning illumination and one-dimensional slit-scanning detection with a photo-multiplier tube instead of a CCD camera. By

  5. Development of a New Low-Cost Indoor Mapping System - System Design, System Calibration and First Results

    Science.gov (United States)

    Kersten, T. P.; Stallmann, D.; Tschirschwitz, F.

    2016-06-01

    For mapping of building interiors various 2D and 3D indoor surveying systems are available today. These systems essentially differ from each other by price and accuracy as well as by the effort required for fieldwork and post-processing. The Laboratory for Photogrammetry & Laser Scanning of HafenCity University (HCU) Hamburg has developed, as part of an industrial project, a lowcost indoor mapping system, which enables systematic inventory mapping of interior facilities with low staffing requirements and reduced, measurable expenditure of time and effort. The modelling and evaluation of the recorded data take place later in the office. The indoor mapping system of HCU Hamburg consists of the following components: laser range finder, panorama head (pan-tilt-unit), single-board computer (Raspberry Pi) with digital camera and battery power supply. The camera is pre-calibrated in a photogrammetric test field under laboratory conditions. However, remaining systematic image errors are corrected simultaneously within the generation of the panorama image. Due to cost reasons the camera and laser range finder are not coaxially arranged on the panorama head. Therefore, eccentricity and alignment of the laser range finder against the camera must be determined in a system calibration. For the verification of the system accuracy and the system calibration, the laser points were determined from measurements with total stations. The differences to the reference were 4-5mm for individual coordinates.

  6. Traceable Pyrgeometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina

    2016-05-02

    This poster presents the development, implementation, and operation of the Broadband Outdoor Radiometer Calibrations (BORCAL) Longwave (LW) system at the Southern Great Plains Radiometric Calibration Facility for the calibration of pyrgeometers that provide traceability to the World Infrared Standard Group.

  7. Self-calibration of a cone-beam micro-CT system

    International Nuclear Information System (INIS)

    Use of cone-beam computed tomography (CBCT) is becoming more frequent. For proper reconstruction, the geometry of the CBCT systems must be known. While the system can be designed to reduce errors in the geometry, calibration measurements must still be performed and corrections applied. Investigators have proposed techniques using calibration objects for system calibration. In this study, the authors present methods to calibrate a rotary-stage CB micro-CT (CBμCT) system using only the images acquired of the object to be reconstructed, i.e., without the use of calibration objects. Projection images are acquired using a CBμCT system constructed in the authors' laboratories. Dark- and flat-field corrections are performed. Exposure variations are detected and quantified using analysis of image regions with an unobstructed view of the x-ray source. Translations that occur during the acquisition in the horizontal direction are detected, quantified, and corrected based on sinogram analysis. The axis of rotation is determined using registration of antiposed projection images. These techniques were evaluated using data obtained with calibration objects and phantoms. The physical geometric axis of rotation is determined and aligned with the rotational axis (assumed to be the center of the detector plane) used in the reconstruction process. The parameters describing this axis agree to within 0.1 mm and 0.3 deg with those determined using other techniques. Blurring due to residual calibration errors has a point-spread function in the reconstructed planes with a full-width-at-half-maximum of less than 125 μm in a tangential direction and essentially zero in the radial direction for the rotating object. The authors have used this approach on over 100 acquisitions over the past 2 years and have regularly obtained high-quality reconstructions, i.e., without artifacts and no detectable blurring of the reconstructed objects. This self-calibrating approach not only obviates

  8. Upgrade of the Laser Calibration System for the ATLAS Hadronic Calorimeter TileCal

    CERN Document Server

    Van Woerden, Marius Cornelis; The ATLAS collaboration

    2015-01-01

    We present in this contribution the new system for laser calibration of the ATLAS hadronic calorimeter TileCal. The laser system is a part of the three stage calibration apparatus designed to compute the calibration constants of the individual cells of TileCal. The laser system is mainly used to correct for short term (one month) drifts of the readout of the individual cells. A sub-percent accuracy in the control of the calibration constants is required to keep the systematics effects introduced by relative cell miscalibration below the irreducible systematics in determining the parameters of the reconstructed hadronic jets. To achieve this goal in the LHC Run 2 conditions, a new laser system was designed. The architecture of the system is described with details on the new optical line used to distribute laser pulses in each individual detector module and on the new electronics used to drive the laser, to readout the system optical monitors and to interface the system with the Atlas readout, trigger, and slow...

  9. Primary calibration system for vibration transducers from 0.4 Hz to 160 Hz

    International Nuclear Information System (INIS)

    This paper presents a system developed at the Vibration Laboratory of Inmetro, which is used for primary calibration of vibration transducers by the fringe counting method. This system includes a vibration exciter, a Michelson interferometer, a data acquisition board, a band-pass filter, a universal counter and a software for measurement automation. It allows the laboratory to perform calibrations in accordance with the international standard ISO 16063-11 in the frequency range from 0.4 Hz to 160 Hz. Some experimental results are presented herein

  10. Calibration Issues and Operating System Requirements for Electron-Probe Microanalysis

    Science.gov (United States)

    Carpenter, P.

    2006-01-01

    Instrument purchase requirements and dialogue with manufacturers have established hardware parameters for alignment, stability, and reproducibility, which have helped improve the precision and accuracy of electron microprobe analysis (EPMA). The development of correction algorithms and the accurate solution to quantitative analysis problems requires the minimization of systematic errors and relies on internally consistent data sets. Improved hardware and computer systems have resulted in better automation of vacuum systems, stage and wavelength-dispersive spectrometer (WDS) mechanisms, and x-ray detector systems which have improved instrument stability and precision. Improved software now allows extended automated runs involving diverse setups and better integrates digital imaging and quantitative analysis. However, instrumental performance is not regularly maintained, as WDS are aligned and calibrated during installation but few laboratories appear to check and maintain this calibration. In particular, detector deadtime (DT) data is typically assumed rather than measured, due primarily to the difficulty and inconvenience of the measurement process. This is a source of fundamental systematic error in many microprobe laboratories and is unknown to the analyst, as the magnitude of DT correction is not listed in output by microprobe operating systems. The analyst must remain vigilant to deviations in instrumental alignment and calibration, and microprobe system software must conveniently verify the necessary parameters. Microanalysis of mission critical materials requires an ongoing demonstration of instrumental calibration. Possible approaches to improvements in instrument calibration, quality control, and accuracy will be discussed. Development of a set of core requirements based on discussions with users, researchers, and manufacturers can yield documents that improve and unify the methods by which instruments can be calibrated. These results can be used to

  11. Numerical simulation of cold conduction structure thermal performance in Hall probe cryogenic calibration system

    International Nuclear Information System (INIS)

    Background: The cryogenic calibration system of Hall probe is an important tool for high precision magnetic measurement at low temperature. Purpose: In order to setup the calibration system, simulations are performed to study the temperature distribution and thermal deformation of the conduction components which have a direct impact on the Hall probe calibration. Methods: Finite element method was used to the steady thermal analysis and cord deformation analysis. Joule effect of the Hall sensor at low temperature was simulated, and temperature differences from the Joule effect were then figured out. Results: When the temperature of the secondary cold head is 4.42 K, the simulated temperature of the Hall probe is 6.75 K, and the simulation result of Hall probe axial deformation is 1.11 mm. Experimental result of the temperature of hall probe is 6.44 K. Conclusion: The simulation result is reliable and can provide the basis for Hall probe temperature correction. (authors)

  12. A Calibration System for Compton Polarimetry at $e^+e^-$ Linear Colliders

    CERN Document Server

    Vormwald, Benedikt; Vauth, Annika

    2015-01-01

    Polarimetry with permille-level precision is essential for future electron-positron linear colliders. Compton polarimeters can reach negligible statistical uncertainties within seconds of measurement time. The dominating systematic uncertainties originate from the response and alignment of the detector which records the Compton scattered electrons. The robust baseline technology for the Compton polarimeters foreseen at future linear colliders is based on an array of gas Cherenkov detectors read out by photomultipliers. In this paper, we will present a calibration method which promises to monitor nonlinearities in the response of such a detector at the level of a few permille. This method has been implemented in an LED-based calibration system which matches the existing prototype detector. The performance of this calibration system is sufficient to control the corresponding contribution to the total uncertainty on the extracted polarisation to better than $0.1\\%$.

  13. A calibration system for Compton polarimetry at e{sup +}e{sup -} linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Vormwald, Benedikt; Vauth, Annika [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-09-15

    Polarimetry with permille-level precision is essential for future electron-positron linear colliders. Compton polarimeters can reach negligible statistical uncertainties within seconds of measurement time. The dominating systematic uncertainties originate from the response and alignment of the detector which records the Compton scattered electrons. The robust baseline technology for the Compton polarimeters foreseen at future linear colliders is based on an array of gas Cherenkov detectors read out by photomultipliers. In this paper, we will present a calibration method which promises to monitor nonlinearities in the response of such a detector at the level of a few permille. This method has been implemented in an LED-based calibration system which matches the existing prototype detector. The performance of this calibration system is sufficient to control the corresponding contribution to the total uncertainty on the extracted polarisation to better than 0.1%.

  14. The Calibration Model and Simulation Analysis of Circular Scanning Airborne Laser Bathymetry System

    Directory of Open Access Journals (Sweden)

    SHEN Erhua

    2016-08-01

    Full Text Available To improve the positioning accuracy of circular scanning airborne laser bathymetry system, a calibration method is presented in this paper. When the laser points are collected by the bathymetry system on the level area, they should be on the same plane. However, they are not coplanar because of systematic error and random error. So we try to fit the points to a plane, which may help to adjust the errors and then correct the point location.Firstly, the circular scanning airborne laser bathymetry positioning model is derived in the simple mode. The intersection of laser line and sea surface is simulated depending on the mathematical principles of line and plane intersection. Combined with the direction vector of laser line in the water got by the refraction principle, the sea floor plane mathematical equation is used to compute the location of the laser points. Then, the parameter weighted least squares adjustment model is derived with the prior variance introduced, which lays the foundation for the following computing of calibration model. Finally, the calibration adjustment mathematic model and the detailed computing process are derived. The simulation computing and analysis for the calibration process is presented, and some meaningful conclusions for the calibration are achieved.

  15. Geometrical calibration television measuring systems with solid state photodetectors

    Science.gov (United States)

    Matiouchenko, V. G.; Strakhov, V. V.; Zhirkov, A. O.

    2000-11-01

    The various optical measuring methods for deriving information about the size and form of objects are now used in difference branches- mechanical engineering, medicine, art, criminalistics. Measuring by means of the digital television systems is one of these methods. The development of this direction is promoted by occurrence on the market of various types and costs small-sized television cameras and frame grabbers. There are many television measuring systems using the expensive cameras, but accuracy performances of low cost cameras are also interested for the system developers. For this reason inexpensive mountingless camera SK1004CP (format 1/3', cost up to 40$) and frame grabber Aver2000 were used in experiments.

  16. Advanced photovoltaic power systems using tandem GaAs/GaSb concentrator modules

    Science.gov (United States)

    Fraas, L. M.; Kuryla, M. S.; Pietila, D. A.; Sundaram, V. S.; Gruenbaum, P. E.; Avery, J. E.; Dihn, V.; Ballantyne, R.; Samuel, C.

    1992-01-01

    In 1989, Boeing announced the fabrication of a tandem gallium concentrator solar cell with an energy conversion efficiency of 30 percent. This research breakthrough has now led to panels which are significantly smaller, lighter, more radiation resistant, and potentially less expensive than the traditional silicon flat plate electric power supply. The new Boeing tandem concentrator (BTC) module uses an array of lightweight silicone Fresnel lenses mounted on the front side of a light weight aluminum honeycomb structure to focus sunlight onto small area solar cells mounted on a thin back plane. This module design is shown schematically. The tandem solar cell in this new module consists of a gallium arsenide light sensitive cell with a 24 percent energy conversion efficiency stacked on top of a gallium antimonide infrared sensitive cell with a conversion efficiency of 6 percent. This gives a total efficiency 30 percent for the cell-stack. The lens optical efficiency is typically 85 percent. Discounting for efficiency losses associated with lens packing, cell wiring, and cell operating temperature still allows for a module efficiency of 22 percent which leads to a module power density of 300 Watts/sq. m. This performance provides more than twice the power density available from a single crystal silicon flat plate module and at least four times the power density available from amorphous silicon modules. The fact that the lenses are only 0.010 ft. thick and the aluminum foil back plane is only 0.003 ft. thick leads to a very lightweight module. Although the cells are an easy to handle thickness of 0.020 ft., the fact that they are small, occupying one-twenty-fifth of the module area, means that they add little to the module weight. After summing all the module weights and given the high module power, we find that we are able to fabricate BTC modules with specific power of 100 watts/kg.

  17. Precision calibration method for binocular vision measurement systems based on arbitrary translations and 3D-connection information

    Science.gov (United States)

    Yang, Jinghao; Jia, Zhenyuan; Liu, Wei; Fan, Chaonan; Xu, Pengtao; Wang, Fuji; Liu, Yang

    2016-10-01

    Binocular vision systems play an important role in computer vision, and high-precision system calibration is a necessary and indispensable process. In this paper, an improved calibration method for binocular stereo vision measurement systems based on arbitrary translations and 3D-connection information is proposed. First, a new method for calibrating the intrinsic parameters of binocular vision system based on two translations with an arbitrary angle difference is presented, which reduces the effect of the deviation of the motion actuator on calibration accuracy. This method is simpler and more accurate than existing active-vision calibration methods and can provide a better initial value for the determination of extrinsic parameters. Second, a 3D-connection calibration and optimization method is developed that links the information of the calibration target in different positions, further improving the accuracy of the system calibration. Calibration experiments show that the calibration error can be reduced to 0.09%, outperforming traditional methods for the experiments of this study.

  18. A new in situ electrical calibration system for high temperature Calvet calorimeters.

    Science.gov (United States)

    Razouk, Refat; Hay, Bruno; Himbert, Marc

    2013-09-01

    A new in situ high temperature electrical calibration system was developed at Laboratoire National de Metrologie et d'Essais, Laboratoire Commun de Metrologie and integrated into a heat flux Calvet calorimeter in order to perform accurate and reliable measurements of enthalpy of fusion that are directly traceable to the International System of Units (SI). This system has been designed to enable the calibration of the calorimeter by electrical substitution (Joule effect) as well as the measurement of enthalpy of fusion in perfectly identical experimental conditions. The metrological features (repeatability, linearity, etc.) of the calorimeter have been evaluated with this system by investigating the influence of some parameters (level of energy, dissipation time, and temperature) on the determination of the sensitivity factor of its thermopiles. Two different procedures, for the calibration and the enthalpy measurements with this new electrical calibration system, have been implemented and tested by measuring the enthalpy of fusion of high purity 6N tin. The results obtained are in very good agreement with those measured by other National Metrology Institutes on the same material.

  19. A measurement technique to determine the calibration accuracy of an electromagnetic tracking system to radiation isocenter

    Energy Technology Data Exchange (ETDEWEB)

    Litzenberg, Dale W.; Gallagher, Ian; Masi, Kathryn J.; Lee, Choonik; Prisciandaro, Joann I.; Hamstra, Daniel A.; Ritter, Timothy; Lam, Kwok L. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109-5010 (United States)

    2013-08-15

    Purpose: To present and characterize a measurement technique to quantify the calibration accuracy of an electromagnetic tracking system to radiation isocenter.Methods: This technique was developed as a quality assurance method for electromagnetic tracking systems used in a multi-institutional clinical hypofractionated prostate study. In this technique, the electromagnetic tracking system is calibrated to isocenter with the manufacturers recommended technique, using laser-based alignment. A test patient is created with a transponder at isocenter whose position is measured electromagnetically. Four portal images of the transponder are taken with collimator rotations of 45° 135°, 225°, and 315°, at each of four gantry angles (0°, 90°, 180°, 270°) using a 3 × 6 cm{sup 2} radiation field. In each image, the center of the copper-wrapped iron core of the transponder is determined. All measurements are made relative to this transponder position to remove gantry and imager sag effects. For each of the 16 images, the 50% collimation edges are identified and used to find a ray representing the rotational axis of each collimation edge. The 16 collimator rotation rays from four gantry angles pass through and bound the radiation isocenter volume. The center of the bounded region, relative to the transponder, is calculated and then transformed to tracking system coordinates using the transponder position, allowing the tracking system's calibration offset from radiation isocenter to be found. All image analysis and calculations are automated with inhouse software for user-independent accuracy. Three different tracking systems at two different sites were evaluated for this study.Results: The magnitude of the calibration offset was always less than the manufacturer's stated accuracy of 0.2 cm using their standard clinical calibration procedure, and ranged from 0.014 to 0.175 cm. On three systems in clinical use, the magnitude of the offset was found to be 0.053

  20. Self-Calibrating, Variable-Flow Pumping System

    Science.gov (United States)

    Walls, Joe T.

    1994-01-01

    Pumping system provides accurate, controlled flows of two chemical liquids mixed in spray head and react to form rigid or flexible polyurethane or polyisocyanurate foam. Compatible with currently used polyurethane-based coating materials and gas-bubble-forming agents (called "blowing agents" in industry) and expected to be compatible with materials that used in near future. Handles environmentally acceptable substitutes for chlorofluorocarbon foaming agents.

  1. Energy Performance Assessment of Radiant Cooling System through Modeling and Calibration at Component Level

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Yasin [Malaviya National Institute of Technology (MNIT), Jaipur, India; Mathur, Jyotirmay [Malaviya National Institute of Technology (MNIT), Jaipur, India; Bhandari, Mahabir S [ORNL

    2016-01-01

    The paper describes a case study of an information technology office building with a radiant cooling system and a conventional variable air volume (VAV) system installed side by side so that performancecan be compared. First, a 3D model of the building involving architecture, occupancy, and HVAC operation was developed in EnergyPlus, a simulation tool. Second, a different calibration methodology was applied to develop the base case for assessing the energy saving potential. This paper details the calibration of the whole building energy model to the component level, including lighting, equipment, and HVAC components such as chillers, pumps, cooling towers, fans, etc. Also a new methodology for the systematic selection of influence parameter has been developed for the calibration of a simulated model which requires large time for the execution. The error at the whole building level [measured in mean bias error (MBE)] is 0.2%, and the coefficient of variation of root mean square error (CvRMSE) is 3.2%. The total errors in HVAC at the hourly are MBE = 8.7% and CvRMSE = 23.9%, which meet the criteria of ASHRAE 14 (2002) for hourly calibration. Different suggestions have been pointed out to generalize the energy saving of radiant cooling system through the existing building system. So a base case model was developed by using the calibrated model for quantifying the energy saving potential of the radiant cooling system. It was found that a base case radiant cooling system integrated with DOAS can save 28% energy compared with the conventional VAV system.

  2. An investigation into force-moment calibration techniques applicable to a magnetic suspension and balance system. M.S. Thesis

    Science.gov (United States)

    Eskins, Jonathan

    1988-01-01

    The problem of determining the forces and moments acting on a wind tunnel model suspended in a Magnetic Suspension and Balance System is addressed. Two calibration methods were investigated for three types of model cores, i.e., Alnico, Samarium-Cobalt, and a superconducting solenoid. Both methods involve calibrating the currents in the electromagnetic array against known forces and moments. The first is a static calibration method using calibration weights and a system of pulleys. The other method, dynamic calibration, involves oscillating the model and using its inertia to provide calibration forces and moments. Static calibration data, found to produce the most reliable results, is presented for three degrees of freedom at 0, 15, and -10 deg angle of attack. Theoretical calculations are hampered by the inability to represent iron-cored electromagnets. Dynamic calibrations, despite being quicker and easier to perform, are not as accurate as static calibrations. Data for dynamic calibrations at 0 and 15 deg is compared with the relevant static data acquired. Distortion of oscillation traces is cited as a major source of error in dynamic calibrations.

  3. Acoustic Self-Calibrating System for Indoor Smart Phone Tracking

    OpenAIRE

    Alexander Ens; Fabian Höflinger; Johannes Wendeberg; Joachim Hoppe; Rui Zhang; Amir Bannoura; Leonhard M. Reindl; Christian Schindelhauer

    2015-01-01

    This paper presents an acoustic indoor localization system for commercial smart phones that emit high pitched acoustic signals beyond the audible range. The acoustic signals with an identifier code modulated on the signal are detected by self-built receivers which are placed at the ceiling or on walls in a room. The receivers are connected in a Wi-Fi network, such that they synchronize their clocks and exchange the time differences of arrival (TDoA) of the received chirps. The location of the...

  4. Effective x-ray attenuation coefficient measurements from two full field digital mammography systems for data calibration applications

    Directory of Open Access Journals (Sweden)

    Thomas Jerry A

    2008-03-01

    Full Text Available Abstract Background Breast density is a significant breast cancer risk factor. Currently, there is no standard method for measuring this important factor. Work presented here represents an essential component of an ongoing project that seeks to determine the appropriate method for calibrating (standardizing mammography image data to account for the x-ray image acquisition influences. Longer term goals of this project are to make accurate breast density measurements in support of risk studies. Methods Logarithmic response calibration curves and effective x-ray attenuation coefficients were measured from two full field digital mammography (FFDM systems with breast tissue equivalent phantom imaging and compared. Normalization methods were studied to assess the possibility of reducing the amount of calibration data collection. The percent glandular calibration map functional form was investigated. Spatial variations in the calibration data were used to assess the uncertainty in the calibration application by applying error propagation analyses. Results Logarithmic response curves are well approximated as linear. Measured effective x-ray attenuation coefficients are characteristic quantities independent of the imaging system and are in agreement with those predicted numerically. Calibration data collection can be reduced by applying a simple normalization technique. The calibration map is well approximated as linear. Intrasystem calibration variation was on the order of four percent, which was approximately half of the intersystem variation. Conclusion FFDM systems provide a quantitative output, and the calibration quantities presented here may be used for data acquired on similar FFDM systems.

  5. Self Calibration of a vision system embedded in a Visual SLAM framework

    OpenAIRE

    Joly, Cyril; Rives, Patrick

    2011-01-01

    International audience This paper presents a novel approach to self calibrate the extrinsic parameters of a camera mounted on a mobile robot in the context of fusion with the odometry sensor. Calibrating precisely such system can be difficult if the camera is mounted on a vehicule where the frame is difficult to localize precisely (like on a car for example). However, the knowledge of the camera pose in the robot frame is essential in order to make a consistent fusion of the sensor measure...

  6. A Fast Calibration System for SiPM Based Scintillator HCAL Detector

    CERN Document Server

    Polak, I

    2015-01-01

    with mid-range a fixed-intensity light pulse. The full SiPM response function is cross-checked by varying the light intensity from zero to the saturation level. In calibration systems we developed, we concentrate especially on the aspect a high dynamic range of pre...

  7. A NEW ELECTRONIC BOARD TO DRIVE THE LASER CALIBRATION SYSTEM OF THE ATLAS HADRON CALORIMETER

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00086824; The ATLAS collaboration

    2016-01-01

    The LASER calibration system of the ATLAS hadron calorimeter aims at monitoring the ~10000 PMTs of the TileCal. The LASER light injected in the PMTs is measured by sets of photodiodes at several stages of the optical path. The monitoring of the photodiodes is performed by a redundant internal calibration system using an LED, a radioactive source, and a charge injection system. The LASer Calibration Rod (LASCAR) electronics card is a major component of the LASER calibration scheme. Housed in a VME crate, its main components include a charge ADC, a TTCRx, a HOLA part, an interface to control the LASER, and a charge injection system. The 13 bits ADC is a 2000pc full-scale converter that processes up to 16 signals stemming from 11 photodiodes, 2 PMTs, and 3 charge injection channels. Two gains are used (x1 and x4) to increase the dynamic range and avoid a saturation of the LASER signal for high intensities. The TTCRx chip (designed by CERN) retrieves LHC signals to synchronize the LASCAR card with the collider. T...

  8. An interferometric calibration system for various linear artefacts using active compensation of angular motion errors

    International Nuclear Information System (INIS)

    A calibration system for linear-dimension artefacts was developed, which employed a multi-axis laser interferometer for direct metrological traceability and active compensation of angular motion errors. It can calibrate various end and line standards by changing probes (contact and optical probe). We designed the system as a moving probe type with a cantilever structure to reduce overall size and increase efficiency in calibration. A stage part including a two-axis tilt stage provides precise linear motion of a probing part over the range of 2000 mm with nanometric resolution. The three-axis interferometer measuring linear and rotational motions of the stage enables us to obtain probing position and compensate angular motion errors precisely. It was also arranged to minimize the Abbe offset, and so the Abbe error can be reduced remarkably combining the active compensation of angular motion errors. The overall system was installed in a temperature-controlled chamber to decrease thermal variation during measurements. The measurement uncertainty of the calibration system was analysed by considering the performance of the main components. We measured several long gauge blocks and a precision line scale, and compared the measured values with the reference ones and also checked their stabilities. Their deviations were less than 100 nm and existed within the expanded measurement uncertainty (k = 2)

  9. Lake Mead dynamic test range for calibration of airborne gamma radiation measuring systems

    International Nuclear Information System (INIS)

    Data are presented for calibrating airborne gamma radiation measuring systems for surface concentrations of U, Th, and K. Data are included for six flight paths at altitudes of 200, 400, 600, 800, 1000, and 1200 feet. Lake Mead Dynamic Test Range is described in detail in Volume I of this report

  10. Lake Mead dynamic test range for calibration of airborne gamma radiation measuring systems

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    Data are presented for calibrating airborne gamma radiation measuring systems for surface concentrations of U, Th, and K. Data are included for six flight paths at altitudes of 200, 400, 600, 800, 1000, and 1200 feet. Lake Mead Dynamic Test Range is described in detail in Volume I of this report. (WHK)

  11. The Calibration of High-Speed Camera Imaging System for ELMs Observation on EAST Tokamak

    Science.gov (United States)

    Fu, Chao; Zhong, Fangchuan; Hu, Liqun; Yang, Jianhua; Yang, Zhendong; Gan, Kaifu; Zhang, Bin; East Team

    2016-09-01

    A tangential fast visible camera has been set up in EAST tokamak for the study of edge MHD instabilities such as ELM. To determine the 3-D information from CCD images, Tsai's two-stage technique was utilized to calibrate the high-speed camera imaging system for ELM study. By applying tiles of the passive stabilizers in the tokamak device as the calibration pattern, transformation parameters for transforming from a 3-D world coordinate system to a 2-D image coordinate system were obtained, including the rotation matrix, the translation vector, the focal length and the lens distortion. The calibration errors were estimated and the results indicate the reliability of the method used for the camera imaging system. Through the calibration, some information about ELM filaments, such as positions and velocities were obtained from images of H-mode CCD videos. supported by National Natural Science Foundation of China (No. 11275047), the National Magnetic Confinement Fusion Science Program of China (No. 2013GB102000)

  12. Calibration and characterisation with a new laser-based magnetostriction measurement system

    OpenAIRE

    Rafferty, Aran; Bakir, S.; Brabazon, Dermot; Prescott, Tim

    2009-01-01

    A laser-based magnet measurement system has been developed to measure the magnetostrictive strain of large cylindrical samples. The measurement system incorporates a solenoid capable of generating a maximum magnetic field intensity of 3000 Oe and a laser displacement sensor. For calibration and evaluation purposes, the positive magnetostrictions of two different types of giant magnetostrictive Tb–Dy–Fe-based materials were accessed with this system. A magnetostrictive strain of 622 ppm was ob...

  13. Omnidirectional multi-view systems: Calibration, features and 3D information

    OpenAIRE

    Puig Morales, Luis; Guerrero Campo, José Jesús

    2012-01-01

    In this thesis we focus on omnidirectional multi-view systems, in particular central catadioptric systems. We go from the very early step of calibration to the high level task of 3D information recovery. We also consider a very important intermediate step, which is the development of properly adapted features for central catadioptric systems. In the following paragraphs we describe in moredetail the goals reached on this thesis. We selected the sphere camera model to deal with the central cat...

  14. Automatic calibration and signal switching system for the particle beam fusion research data acquisition facility

    International Nuclear Information System (INIS)

    This report describes both the hardware and software components of an automatic calibration and signal system (Autocal) for the data acquisition system for the Sandia particle beam fusion research accelerators Hydra, Proto I, and Proto II. The Autocal hardware consists of off-the-shelf commercial equipment. The various hardware components, special modifications and overall system configuration are described. Special software has been developed to support the Autocal hardware. Software operation and maintenance are described

  15. Calibration target reconstruction for 3-D vision inspection system of large-scale engineering objects

    Science.gov (United States)

    Yin, Yongkai; Peng, Xiang; Guan, Yingjian; Liu, Xiaoli; Li, Ameng

    2010-11-01

    It is usually difficult to calibrate the 3-D vision inspection system that may be employed to measure the large-scale engineering objects. One of the challenges is how to in-situ build-up a large and precise calibration target. In this paper, we present a calibration target reconstruction strategy to solve such a problem. First, we choose one of the engineering objects to be inspected as a calibration target, on which we paste coded marks on the object surface. Next, we locate and decode marks to get homologous points. From multiple camera images, the fundamental matrix between adjacent images can be estimated, and then the essential matrix can be derived with priori known camera intrinsic parameters and decomposed to obtain camera extrinsic parameters. Finally, we are able to obtain the initial 3D coordinates with binocular stereo vision reconstruction, and then optimize them with the bundle adjustment by considering the lens distortions, leading to a high-precision calibration target. This reconstruction strategy has been applied to the inspection of an industrial project, from which the proposed method is successfully validated.

  16. A new slit stabilization system for the beam energy at the Bucharest tandem Van de Graaff accelerator

    Science.gov (United States)

    Moşu, D. V.; Ghiţă, D. G.; Dobrescu, S.; Sava, T.; Mitu, I. O.; Călinescu, I. C.; Naghel, G.; Dumitru, G.; Căta-Danil, Gh.

    2012-11-01

    Recent work has been undertaken to renew the stabilization system for the beam energy at the Bucharest Tandem Accelerator. In the present paper the mechatronic design of the new system is presented and the running consistency of the new electronic circuits is shown. The experimental tests have shown that the new system has improved the quality of the accelerated beams in terms of stability and energy resolution, especially at lower accelerating voltages. As a result of the present development we show an improvement with 20% for the peak to peak medium value of the high voltage ripple on the terminal. This improvement also allowed to lower the minimum stable voltage on the terminal from 1.5 MV to 0.8 MV.

  17. The use of liquid chromatography tandem mass spectrometry to detect proteins in saliva from horses with and without systemic inflammation.

    Science.gov (United States)

    Jacobsen, Stine; Top Adler, Ditte Marie; Bundgaard, Louise; Sørensen, Mette Aamand; Andersen, Pia Haubro; Bendixen, Emøke

    2014-12-01

    The objective of the study was to assess global expression of proteins in equine saliva using liquid chromatography tandem mass spectrometry (LC-MS/MS). Saliva was obtained from seven horses with and six horses without evidence of systemic inflammatory disease. Tryptic peptides from saliva were analysed by LC-MS/MS. Of 195 unique proteins identified, 57 were detected only in saliva samples from horses with systemic inflammation (in two to six of the seven horses). Among the differentially expressed proteins were several acute phase proteins (APPs) such as serum amyloid A, fibrinogen, haptoglobin, and alpha1-acid glycoprotein. The study is the first to describe detection of inflammatory proteins in horse saliva. The proteins detected were similar to those described in saliva from cattle, small ruminants and pigs. Detection of APPs in horses with systemic inflammation suggests that saliva may be used for non-invasive disease monitoring in horses as in humans, pigs and dogs. PMID:25296850

  18. The use of liquid chromatography tandem mass spectrometry to detect proteins in saliva from horses with and without systemic inflammation

    DEFF Research Database (Denmark)

    Jacobsen, Stine; Top Adler, Ditte Marie; Bundgaard, Louise;

    2014-01-01

    The objective of the study was to assess global expression of proteins in equine saliva using liquid chromatography tandem mass spectrometry (LC-MS/MS). Saliva was obtained from seven horses with and six horses without evidence of systemic inflammatory disease. Tryptic peptides from saliva were...... analysed by LC-MS/MS. Of 195 unique proteins identified, 57 were detected only in saliva samples from horses with systemic inflammation (in two to six of the seven horses). Among the differentially expressed proteins were several acute phase proteins (APPs) such as serum amyloid A, fibrinogen, haptoglobin......, and alpha1-acid glycoprotein. The study is the first to describe detection of inflammatory proteins in horse saliva. The proteins detected were similar to those described in saliva from cattle, small ruminants and pigs. Detection of APPs in horses with systemic inflammation suggests that saliva may be...

  19. Monte Carlo Studies for the Calibration System of the GERDA Experiment

    CERN Document Server

    Baudis, Laura; Froborg, Francis; Tarka, Michal

    2013-01-01

    The GERmanium Detector Array, GERDA, searches for neutrinoless double beta decay in Ge-76 using bare high-purity germanium detectors submerged in liquid argon. For the calibration of these detectors gamma emitting sources have to be lowered from their parking position on top of the cryostat over more than five meters down to the germanium crystals. With the help of Monte Carlo simulations, the relevant parameters of the calibration system were determined. It was found that three Th-228 sources with an activity of 20 kBq each at two different vertical positions will be necessary to reach sufficient statistics in all detectors in less than four hours of calibration time. These sources will contribute to the background of the experiment with a total of (1.07 +/- 0.04(stat) +0.13 -0.19(sys)) 10^{-4} cts/(keV kg yr) when shielded from below with 6 cm of tantalum in the parking position.

  20. Scanner external calibration algorithm based on fixed point in robot remanufacturing system

    Institute of Scientific and Technical Information of China (English)

    ZHU Sheng; CUI Pei-zhi; SHEN Chan-duo; GUO Ying-chun

    2005-01-01

    This paper deals with the scanner exterior calibration algorithm when the scanner is arranged by the robot and the object scanned is fixed on a rotate device in the Robot Remanufacturing System. The method of calibrating the relationship between the scanner coordinate and the robot Tool0, such as the rotation, Rx, Ry, R,, and the transformation X, Y, Z is studied. The data of Tool0 can be directly obtained from the relationship with the robot base-coordinate. So, the coordinate relationship between the scanner coordinate and the robot base coordinate can be easily gotten. This paper explains the basic algorithm theory, computing method, data collecting process and the resulted data in detail. The calibration algorithm is deduced under the orthogonal coordinate.

  1. Some tests of wet tropospheric calibration for the CASA Uno Global Positioning System experiment

    Science.gov (United States)

    Dixon, T. H.; Wolf, S. Kornreich

    1990-01-01

    Wet tropospheric path delay can be a major error source for Global Positioning System (GPS) geodetic experiments. Strategies for minimizing this error are investigted using data from CASA Uno, the first major GPS experiment in Central and South America, where wet path delays may be both high and variable. Wet path delay calibration using water vapor radiometers (WVRs) and residual delay estimation is compared with strategies where the entire wet path delay is estimated stochastically without prior calibration, using data from a 270-km test baseline in Costa Rica. Both approaches yield centimeter-level baseline repeatability and similar tropospheric estimates, suggesting that WVR calibration is not critical for obtaining high precision results with GPS in the CASA region.

  2. X-ray system signal derivation circuits for heat unit indicators and/or calibration meters

    International Nuclear Information System (INIS)

    Milliampere and kilovolt signals are monitored from the X-ray tube system high tension transformer. These signals may be connected to a heat unit indicator or a calibration meter or both. With the heat unit indicator, the heat level in an X-ray tube anode is monitored and referred to the level corresponding to the ambient room temperature as zero reference. As successive signal exposures or series of exposures are made, the X-ray tube heat loading is automatically monitored and displayed. The cooling characteristics of the tube are automatically reflected in the reading. A calibration meter may be connected to the signal derivation circuitry to indicate a plurality of operating parameters. The circuitry includes automatic scaling device for maintaining the relatively accurate signals required for the accurate operation of the heat indicator and the calibration meter. (UK)

  3. Emerging Techniques for Vicarious Calibration of Visible Through Short Wave Infrared Remote Sensing Systems

    Science.gov (United States)

    Ryan, Robert E.; Harrington, Gary; Holekamp, Kara; Pagnutti, Mary; Russell, Jeffrey; Frisbie, Troy; Stanley, Thomas

    2007-01-01

    Autonomous Visible to SWIR ground-based vicarious Cal/Val will be an essential Cal/Val component with such a large number of systems. Radiometrically calibrated spectroradiometers can improve confidence in current ground truth data through validation of radiometric modeling and validation or replacement of traditional sun photometer measurement. They also should enable significant reduction in deployed equipment such as equipment used in traditional sun photometer approaches. Simple, field-portable, white-light LED calibration source shows promise for visible range (420-750 nm). Prototype demonstrated <0.5% drift over 10-40 C temperature range. Additional complexity (more LEDs) will be necessary for extending spectral range into the NIR and SWIR. LED long lifetimes should produce at least several hundreds of hours or more of stability, minimizing the need for expensive calibrations and supporting long-duration field campaigns.

  4. Calibration grooming and alignment for LDUA High Resolution Stereoscopic Video Camera System (HRSVS)

    International Nuclear Information System (INIS)

    The High Resolution Stereoscopic Video Camera System (HRSVS) was designed by the Savannah River Technology Center (SRTC) to provide routine and troubleshooting views of tank interiors during characterization and remediation phases of underground storage tank (UST) processing. The HRSVS is a dual color camera system designed to provide stereo viewing of the interior of the tanks including the tank wall in a Class 1, Division 1, flammable atmosphere. The HRSVS was designed with a modular philosophy for easy maintenance and configuration modifications. During operation of the system with the LDUA, the control of the camera system will be performed by the LDUA supervisory data acquisition system (SDAS). Video and control status 1458 will be displayed on monitors within the LDUA control center. All control functions are accessible from the front panel of the control box located within the Operations Control Trailer (OCT). The LDUA will provide all positioning functions within the waste tank for the end effector. Various electronic measurement instruments will be used to perform CG and A activities. The instruments may include a digital volt meter, oscilloscope, signal generator, and other electronic repair equipment. None of these instruments will need to be calibrated beyond what comes from the manufacturer. During CG and A a temperature indicating device will be used to measure the temperature of the outside of the HRSVS from initial startup until the temperature has stabilized. This device will not need to be in calibration during CG and A but will have to have a current calibration sticker from the Standards Laboratory during any acceptance testing. This sensor will not need to be in calibration during CG and A but will have to have a current calibration sticker from the Standards Laboratory during any acceptance testing

  5. Portable 3D laser-camera calibration system with color fusion for SLAM

    Directory of Open Access Journals (Sweden)

    Javier Navarrete

    2013-03-01

    Full Text Available Nowadays, the use of RGB-D sensors have focused a lot of research in computer vision and robotics. These kinds of sensors, like Kinect, allow to obtain 3D data together with color information. However, their working range is limited to less than 10 meters, making them useless in some robotics applications, like outdoor mapping. In these environments, 3D lasers, working in ranges of 20-80 meters, are better. But 3D lasers do not usually provide color information. A simple 2D camera can be used to provide color information to the point cloud, but a calibration process between camera and laser must be done. In this paper we present a portable calibration system to calibrate any traditional camera with a 3D laser in order to assign color information to the 3D points obtained. Thus, we can use laser precision and simultaneously make use of color information. Unlike other techniques that make use of a three-dimensional body of known dimensions in the calibration process, this system is highly portable because it makes use of small catadioptrics that can be placed in a simple manner in the environment. We use our calibration system in a 3D mapping system, including Simultaneous Location and Mapping (SLAM, in order to get a 3D colored map which can be used in different tasks. We show that an additional problem arises: 2D cameras information is different when lighting conditions change. So when we merge 3D point clouds from two different views, several points in a given neighborhood could have different color information. A new method for color fusion is presented, obtaining correct colored maps. The system will be tested by applying it to 3D reconstruction.

  6. A novel sub-camera array model for calibrating multi-mirror catadioptric systems

    International Nuclear Information System (INIS)

    The omni-directional catadioptric camera composed of multiple mirrors is a powerful tool that can acquire multiple wide field-of-view images and reconstruct the scene in a single shot. However, the non-central nature of the system poses significant challenges to the task of calibration. A novel off-center spherical projection (OCSP)-based sub-camera array model is proposed in this paper to address this problem. By inducing a movable spherical projection center in the traditional unified model, the OCSP sub-camera can efficiently deal with large misalignments that exist in multi-mirror systems. An efficient calibration method and the initialization algorithm are also presented. With the new model, calibration can be completed conveniently without the aid of a priori information on the mirrors and camera. The model is also compatible with traditional multi-view geometry, making 3D reconstruction straightforward for non-central systems. Experiments based on synthetic and real data on various types of mirrors show promising calibration results and thus verify the effectiveness of the method. (paper)

  7. Calibration of a multi-beam Laser System by using a TLS-generated Reference

    Science.gov (United States)

    Gordon, M.; Meidow, J.

    2013-10-01

    Rotating multi-beam LIDARs mounted on moving platforms have become very successful for many applications such as autonomous navigation, obstacle avoidance or mobile mapping. To obtain accurate point coordinates, a precise calibration of such a LIDAR system is required. For the determination of the corresponding parameters we propose a calibration scheme which exploits the information of 3D reference point clouds captured by a terrestrial laser scanning (TLS) device. It is assumed that the accuracy of this point clouds is considerably higher than that from the multi-beam LIDAR and that the data represent faces of man-made objects at different distances. After extracting planes in the reference data sets, the point-plane-incidences of the measured points and the reference planes are used to formulate the implicit constraints. We inspect the Velodyne HDL-64E S2 system as the best-known representative for this kind of sensor system. The usability and feasibility of the calibration procedure is demonstrated with real data sets representing building faces (walls, roof planes and ground). Beside the improvement of the point accuracy by considering the calibration results, we test the significance of the parameters related to the sensor model and consider the uncertainty of measurements w.r.t. the measured distances. The Velodyne returns two kinds of measurements - distances and encoder angles. To account for this, we perform a variance component estimation to obtain realistic standard deviations for the observations.

  8. Calibration of UHF Sensors for GIS: Comparison of Different Methods and Testing of a Calibration System Based on a Conical Antenna%Calibration of UHF Sensors for GIS: Comparison of Different Methods and Testing of a Calibration System Based on a Conical Antenna

    Institute of Scientific and Technical Information of China (English)

    David Gautschi; Pierre Bertholet

    2011-01-01

    Different methods of calibrating ultra high frequency(UHF) sensors for gas-insulated substations (GIS) were investigated in the past. The first approach was to use strip lines, triplates and TEM calibration cells. These cells had already been in use for years for example to test the electromagnetic compatibility of electronic devices. The smaller the size of the cell, the higher its bandwidth-but the cell should be large enough to not disturb the electric field with the installed sensor under test. To overcome this problem, a calibration procedure using a gigahertz transverse e- lectromagnetic(GTEM) test cell and a pulsed signal source were introduced in 1997. Although this procedure has many advantages and is easy to understand, measurements show several shortcomings of this calibration method. To overcome the disadvantages of the known systems, a calibration cell using a monopole cone antenna and a metallic ground plane were developed and tested. The UHF sensor was placed in a region with minimum distortion of the elec- tric field due to its installation. Experience shows that the new method for calibrating UHF sensors is necessary in or- der to overcome the limits in the calibration of large sensors and to suppress the propagation of higher order modes and reflections. Due to its surprisingly simple structure, its low price and low overall measurement uncertainty, it is the preferred method for calibrating UHF sensors for GIS applications.

  9. Calibration of the Multi-camera Registration System for Visual Navigation Benchmarking

    Directory of Open Access Journals (Sweden)

    Adam Schmidt

    2014-06-01

    Full Text Available This paper presents the complete calibration procedure of a multi-camera system for mobile robot motion registration. Optimization-based, purely visual methods for the estimation of the relative poses of the motion registration system cameras, as well as the relative poses of the cameras and markers placed on the mobile robot were proposed. The introduced methods were applied to the calibration of the system and the quality of the obtained results was evaluated. The obtained results compare favourably with the state of the art solutions, allowing the use of the considered motion registration system for the accurate reconstruction of the mobile robot trajectory and to register new datasets suitable for the benchmarking of indoor, visual-based navigation algorithms.

  10. The calibration system for the photomultiplier array of the SNO+ experiment

    CERN Document Server

    Alves, R; Bradbury, S; Carvalho, J; Chauhan, D; Clark, K; Coulter, I; Descamps, F; Falk, E; Gurriana, L; Kraus, C; Lefeuvre, G; Maio, A; Maneira, J; Mottram, M; Peeters, S; Rose, J; Seabra, L; Sinclair, J; Skensved, P; Waterfield, J; White, R; Wilson, J R

    2014-01-01

    A light injection system using LEDs and optical fibres was designed for the calibration and monitoring of the photomultiplier array of the SNO+ experiment at SNOLAB. Large volume, non-segmented, low-background detectors for rare event physics, such as the multi-purpose SNO+ experiment, need a calibration system that allow an accurate and regular measurement of the performance parameters of their photomultiplier arrays, while minimising the risk of radioactivity ingress. The design implemented for SNO+ uses a set of optical fibres to inject light pulses from external LEDs into the detector. The design, fabrication and installation of this light injection system, as well as the first commissioning tests, are described in this paper. Monte Carlo simulations were compared with the commissioning test results, confirming that the system meets the performance requirements.

  11. Comparison of the accuracy of the calibration model on the double and single integrating sphere systems

    Science.gov (United States)

    Singh, A.; Karsten, A.

    2011-06-01

    The accuracy of the calibration model for the single and double integrating sphere systems are compared for a white light system. A calibration model is created from a matrix of samples with known absorption and reduced scattering coefficients. In this instance the samples are made using different concentrations of intralipid and black ink. The total and diffuse transmittance and reflectance is measured on both setups and the accuracy of each model compared by evaluating the prediction errors of the calibration model for the different systems. Current results indicate that the single integrating sphere setup is more accurate than the double system method. This is based on the low prediction errors of the model for the single sphere system for a He-Ne laser as well as a white light source. The model still needs to be refined for more absorption factors. Tests on the prediction accuracies were then determined by extracting the optical properties of solid resin based phantoms for each system. When these properties of the phantoms were used as input to the modeling software excellent agreement between measured and simulated data was found for the single sphere systems.

  12. Design and Instrumentation of a Measurement and Calibration System for an Acoustic Telemetry System

    Directory of Open Access Journals (Sweden)

    Zhiqun Deng

    2010-03-01

    Full Text Available The Juvenile Salmon Acoustic Telemetry System (JSATS is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish-friendly” hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS for evaluating the JSATS components, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS.

  13. Design and instrumentation of a measurement and calibration system for an acoustic telemetry system.

    Science.gov (United States)

    Deng, Zhiqun; Weiland, Mark; Carlson, Thomas; Eppard, M Brad

    2010-01-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more "fish-friendly" hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS) for evaluating the JSATS components, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS. PMID:22319288

  14. Supersonic STOVL fighter concepts featuring the hybrid tandem-fan propulsion system

    Science.gov (United States)

    Gelhausen, P. A.; Wilson, S. B., III

    1986-01-01

    Current research on vertical- or short-takeoff-and-landing (V/STOL) aircraft is concentrating on developing a multirole-capable fighter. Several V/STOL concepts being studied show a capability performing for short-takeoff and vertical-landing (STOVL) missions. This paper is concerned with a propulsion concept which promises added flexibility in mission performance: the hybrid-tandem fan. This propulsion concept is combined with four aircraft planforms and the performance of each is evaluated on a representative mission. The four aircraft planforms used in the study are a conventional wing-tail, a forward-swept wing and canard, a delta-wing and canard, and an oblique wing and tail. The mission was chosen so that the four aircraft all had approximately the same gross takeoff weight. The four designs are compared at various phases of the mission.

  15. Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

    OpenAIRE

    Zheng You; Fei Xing; Ting Sun

    2013-01-01

    The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star ...

  16. Test of candidate light distributors for the muon (g$-$2) laser calibration system

    CERN Document Server

    Anastasi, A; Baffigi, F; Cantatore, G; Cauz, D; Corradi, G; Dabagov, S; Di Sciascio, G; Di Stefano, R; Ferrari, C; Fienberg, A T; Fioretti, A; Fulgentini, L; Gabbanini, C; Gizzi, L A; Hampai, D; Hertzog, D W; Iacovacci, M; Karuza, M; Kaspar, J; Koester, P; Labate, L; Mastroianni, S; Moricciani, D; Pauletta, G; Santi, L; Venanzoni, G

    2015-01-01

    The new muon (g-2) experiment E989 at Fermilab will be equipped with a laser calibration system for all the 1296 channels of the calorimeters. An integrating sphere and an alternative system based on an engineered diffuser have been considered as possible light distributors for the experiment. We present here a detailed comparison of the two based on temporal response, spatial uniformity, transmittance and time stability.

  17. The beam energy calibration system for the BEPC-II collider

    CERN Document Server

    Achasov, M N; Mo, Xiaohu; Muchnoi, N Yu; Qin, Qing; Qu, Huamin; Wang, Yifang; Xu, Jinqiang

    2008-01-01

    This document contains a proposal of the BEPC-II collider beam energy calibration system (IHEP, Beijing). The system is based on Compton backscattering of carbon dioxide laser radiation, producing a beam of high energy photons. Their energy spectrum is then accurately measured by HPGe detector. The high-energy spectrum edge will allow to determine the average electron or positron beam energy with relative accuracy about 3x10^-5.

  18. Presentation, calibration and validation of the low-order, DCESS Earth System Model (Version 1)

    OpenAIRE

    G. Shaffer; S. Malskær Olsen; Pepke Pedersen, J. O.

    2008-01-01

    A new, low-order Earth System Model is described, calibrated and tested against Earth system data. The model features modules for the atmosphere, ocean, ocean sediment, land biosphere and lithosphere and has been designed to simulate global change on time scales of years to millions of years. The atmosphere module considers radiation balance, meridional transport of heat and water vapor between low-mid latitude and high latitude zones, heat and gas exchange with the ocean and sea ice and snow...

  19. PMT response drift of ATLAS Tile Laser II calibration system: an introduction of a new method

    CERN Document Server

    Di Gregorio, Giulia

    2016-01-01

    In this article I describe the performance of the monitoring diodes of the Laser II system, a new system for run II used to calibrate the gain variation of PMTs in between two cesium scan. I also show a new method to measure the PMT drift response that it is compared to the method used up to now (Clermont-Ferrant) corrected with the Pisa method. The agreement between the two method is within 0.2%.

  20. JAERI tandem-accelerator and tandem-booster

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In 1982, aiming at the new development of atomic energy research, the tandem accelerator of Japan Atomic Energy Research Institute (JAERI) was installed. In fiscal year 1993, the superconducting boosters which can increase the ion energy by up to 4 times were added, and the research in the region below 1000 MeV became possible. Those are electrostatic type accelerators which are easy to be used especially in basic research field, and are useful for future research. The tandem accelerator has been operated while maintaining the first class performance as the accelerator for various kinds of heavy ion beam. It has the special shape among electrostatic type accelerators, and is excellent in the easiness of control and stability. The main particulars of the tandem accelerator are shown. As for the ion sources of the tandem accelerator, three cesium sputter type ion sources are installed on two high voltage stands. The kinds of the ions which can be accelerated are mainly negative ions. As the improvement, electron cyclotron resonance (ECR) ion sources are expected to be adopted. As for the tandem boosters, the 1/4 wavelength type resonance hollow cylinder was adopted. The constitution of the tandem boosters is explained. The way of utilizing the tandem accelerator system and the aim for hereafter are reported. (K.I.)

  1. Design of an expert system to automatically calibrate impedance control for powered knee prostheses.

    Science.gov (United States)

    Wang, Ding; Liu, Ming; Zhang, Fan; Huang, He

    2013-06-01

    Many currently available powered knee prostheses (PKP) use finite state impedance control to operate a prosthetic knee joint. The desired impedance values were usually manually calibrated with trial-and-error in order to enable near-normal walking pattern. However, such a manual approach is inaccurate, time consuming, and impractical. This paper aimed to design an expert system that can tune the control impedance for powered knee prostheses automatically and quickly. The expert system was designed based on fuzzy logic inference (FLI) to match the desired knee motion and gait timing while walking. The developed system was validated on an able-bodied subject wearing a powered prosthesis. Preliminary experimental results demonstrated that the developed expert system can converge the user's knee profile and gait timing to the desired values within 2 minutes. Additionally, after the auto-tuning procedure, the user produced more symmetrical gait. These preliminary results indicate the promise of the designed expert system for quick and accuracy impedance calibration, which can significantly improve the practical value of powered lower limb prosthesis. Continuous engineering efforts are still needed to determine the calibration objectives and validate the expert system.

  2. Fueling of tandem mirror reactors

    International Nuclear Information System (INIS)

    This paper summarizes the fueling requirements for experimental and demonstration tandem mirror reactors (TMRs), reviews the status of conventional pellet injectors, and identifies some candidate accelerators that may be needed for fueling tandem mirror reactors. Characteristics and limitations of three types of accelerators are described; neutral beam injectors, electromagnetic rail guns, and laser beam drivers. Based on these characteristics and limitations, a computer module was developed for the Tandem Mirror Reactor Systems Code (TMRSC) to select the pellet injector/accelerator combination which most nearly satisfies the fueling requirements for a given machine design

  3. ISAC time-of-flight system with laser-based calibration

    Energy Technology Data Exchange (ETDEWEB)

    Verzilov, V.A., E-mail: verzilov@triumf.ca

    2015-06-11

    The time-of-flight (TOF) system is available at the ISAC rare isotope facility to measure the energy of stable and radioactive ion beams in the range of 0.5–22 Mev/u. The system, comprised of three secondary electron emission based monitors, is operated with practically all available beam intensities starting from as low as 10{sup 3} ions per second. Recently the system was equipped with the calibration setup based on a 266 nm ultraviolet laser. Laser light interacting with the TOF monitors generates secondary electrons due to the photoelectric effect and acts as a reference beam traveling at a well- known velocity. After calibration, accuracy of energy measurements improved to be better than 0.1%.

  4. Absolute calibration method for fast-streaked, fiber optic light collection, spectroscopy systems.

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Mark D.; Frogget, Brent (National Security Technologies, Las Vegas, NV); Oliver, Bryan Velten; Maron, Yitzhak (Weizmann Institute of Science, Rehovot, Israel); Droemer, Darryl W. (National Security Technologies, Las Vegas, NV); Crain, Marlon D. (National Security Technologies, Las Vegas, NV)

    2010-04-01

    This report outlines a convenient method to calibrate fast (<1ns resolution) streaked, fiber optic light collection, spectroscopy systems. Such a system is used to collect spectral data on plasmas generated in the A-K gap of electron beam diodes fielded on the RITS-6 accelerator (8-12MV, 140-200kA). On RITS, light is collected through a small diameter (200 micron) optical fiber and recorded on a fast streak camera at the output of 1 meter Czerny-Turner monochromator (F/7 optics). To calibrate such a system, it is necessary to efficiently couple light from a spectral lamp into a 200 micron diameter fiber, split it into its spectral components, with 10 Angstroms or less resolution, and record it on a streak camera with 1ns or less temporal resolution.

  5. Double-layer parallelization for hydrological model calibration on HPC systems

    Science.gov (United States)

    Zhang, Ang; Li, Tiejian; Si, Yuan; Liu, Ronghua; Shi, Haiyun; Li, Xiang; Li, Jiaye; Wu, Xia

    2016-04-01

    Large-scale problems that demand high precision have remarkably increased the computational time of numerical simulation models. Therefore, the parallelization of models has been widely implemented in recent years. However, computing time remains a major challenge when a large model is calibrated using optimization techniques. To overcome this difficulty, we proposed a double-layer parallel system for hydrological model calibration using high-performance computing (HPC) systems. The lower-layer parallelism is achieved using a hydrological model, the Digital Yellow River Integrated Model, which was parallelized by decomposing river basins. The upper-layer parallelism is achieved by simultaneous hydrological simulations with different parameter combinations in the same generation of the genetic algorithm and is implemented using the job scheduling functions of an HPC system. The proposed system was applied to the upstream of the Qingjian River basin, a sub-basin of the middle Yellow River, to calibrate the model effectively by making full use of the computing resources in the HPC system and to investigate the model's behavior under various parameter combinations. This approach is applicable to most of the existing hydrology models for many applications.

  6. Users manual for an expert system (HSPEXP) for calibration of the hydrological simulation program; Fortran

    Science.gov (United States)

    Lumb, A.M.; McCammon, R.B.; Kittle, J.L.

    1994-01-01

    Expert system software was developed to assist less experienced modelers with calibration of a watershed model and to facilitate the interaction between the modeler and the modeling process not provided by mathematical optimization. A prototype was developed with artificial intelligence software tools, a knowledge engineer, and two domain experts. The manual procedures used by the domain experts were identified and the prototype was then coded by the knowledge engineer. The expert system consists of a set of hierarchical rules designed to guide the calibration of the model through a systematic evaluation of model parameters. When the prototype was completed and tested, it was rewritten for portability and operational use and was named HSPEXP. The watershed model Hydrological Simulation Program--Fortran (HSPF) is used in the expert system. This report is the users manual for HSPEXP and contains a discussion of the concepts and detailed steps and examples for using the software. The system has been tested on watersheds in the States of Washington and Maryland, and the system correctly identified the model parameters to be adjusted and the adjustments led to improved calibration.

  7. Improving the accuracy and reliability of remote system-calibration-free eye-gaze tracking.

    Science.gov (United States)

    Hennessey, Craig A; Lawrence, Peter D

    2009-07-01

    Remote eye-gaze tracking provides a means for nonintrusive tracking of the point-of-gaze (POG) of a user. For application as a user interface for the disabled, a remote system that is noncontact, reliable, and permits head motion is very desirable. The system-calibration-free pupil-corneal reflection (P-CR) vector technique for POG estimation is a popular method due to its simplicity, however, accuracy has been shown to be degraded with head displacement. Model-based POG-estimation methods were developed, which improve system accuracy during head displacement, however, these methods require complex system calibration in addition to user calibration. In this paper, the use of multiple corneal reflections and point-pattern matching allows for a scaling correction of the P-CR vector for head displacements as well as an improvement in system robustness to corneal reflection distortion, leading to improved POG-estimation accuracy. To demonstrate the improvement in performance, the enhanced multiple corneal reflection P-CR method is compared to the monocular and binocular accuracy of the traditional single corneal reflection P-CR method, and a model-based method of POG estimation for various head displacements. PMID:19272975

  8. Calibration curves of a PGNAA system for cement raw material analysis using the MCNP code

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Carlos; Salgado, Jose

    1998-12-01

    In large samples, the {gamma}-ray count rate of a prompt gamma neutron activation analysis system is a multi-variable function of the elemental dry composition, density, water content and thickness of the material. The experimental calibration curves require tremendous laboratory work, using a great number of standards with well-known compositions. Although a Monte Carlo simulation study does not avoid the experimental calibration work, it reduces the number of experimental calibration standards. This paper is part of a feasibility study for a PGNAA system for on-line continuous characterisation of cement raw material conveyed on a belt (Oliveira, C., Salgado, J. and Carvalho, F. G. (1997) Optimisation of PGNAA instrument design for cement raw materials using the MCNP code. J. Radioanal. Nucl. Chem. 216(2), 191-198; Oliveira, C., Salgado, J., Goncalves, I. F., Carvalho, F. G. and Leitao, F. (1997a) A Monte Carlo study of the influence of geometry arrangements and structural materials on a PGNAA system performance for cement raw materials analysis. Appl. Radiat. Isot. (accepted); Oliveira, C., Salgado, J. and Leitao, F. (1997b) Density and water content corrections in the gamma count rate of a PGNAA system for cement raw material analysis using the MCNP code. Appl. Radiat. Isot. (accepted).]. It reports on the influence of the density, mass water content and thickness on the calibration curves of the PGNAA system. The MCNP-4A code, running in a Pentium-PC and in a DEC workstation, was used to simulate the PGNAA configuration system.

  9. Calibration curves of a PGNAA system for cement raw material analysis using the MCNP code

    International Nuclear Information System (INIS)

    In large samples, the γ-ray count rate of a prompt gamma neutron activation analysis system is a multi-variable function of the elemental dry composition, density, water content and thickness of the material. The experimental calibration curves require tremendous laboratory work, using a great number of standards with well-known compositions. Although a Monte Carlo simulation study does not avoid the experimental calibration work, it reduces the number of experimental calibration standards. This paper is part of a feasibility study for a PGNAA system for on-line continuous characterisation of cement raw material conveyed on a belt (Oliveira, C., Salgado, J. and Carvalho, F. G. (1997) Optimisation of PGNAA instrument design for cement raw materials using the MCNP code. J. Radioanal. Nucl. Chem. 216(2), 191-198; Oliveira, C., Salgado, J., Goncalves, I. F., Carvalho, F. G. and Leitao, F. (1997a) A Monte Carlo study of the influence of geometry arrangements and structural materials on a PGNAA system performance for cement raw materials analysis. Appl. Radiat. Isot. (accepted); Oliveira, C., Salgado, J. and Leitao, F. (1997b) Density and water content corrections in the gamma count rate of a PGNAA system for cement raw material analysis using the MCNP code. Appl. Radiat. Isot. (accepted).]. It reports on the influence of the density, mass water content and thickness on the calibration curves of the PGNAA system. The MCNP-4A code, running in a Pentium-PC and in a DEC workstation, was used to simulate the PGNAA configuration system

  10. Upgrading light hydrocarbons via tandem catalysis: a dual homogeneous Ta/Ir system for alkane/alkene coupling.

    Science.gov (United States)

    Leitch, David C; Lam, Yan Choi; Labinger, Jay A; Bercaw, John E

    2013-07-17

    Light alkanes and alkenes are abundant but are underutilized as energy carriers because of their high volatility and low energy density. A tandem catalytic approach for the coupling of alkanes and alkenes has been developed in order to upgrade these light hydrocarbons into heavier fuel molecules. This process involves alkane dehydrogenation by a pincer-ligated iridium complex and alkene dimerization by a Cp*TaCl2(alkene) catalyst. These two homogeneous catalysts operate with up to 60/30 cooperative turnovers (Ir/Ta) in the dimerization of 1-hexene/n-heptane, giving C13/C14 products in 40% yield. This dual system can also effect the catalytic dimerization of n-heptane (neohexene as the H2 acceptor) with cooperative turnover numbers of 22/3 (Ir/Ta).

  11. A Traceable Ground to On-Orbit Radiometric Calibration System for the Solar Reflective Wavelength Region

    Science.gov (United States)

    Heath, Donald F.; Georgiev, Georgi

    2012-01-01

    This paper describes the combination of a Mie scattering spectral BSDF and BTDF albedo standard whose calibration is traceable to the NIST SIRCUS Facility or the NIST STARR II Facility. The Space-based Calibration Transfer Spectroradiometer (SCATS) sensor uses a simple, invariant optical configuration and dedicated narrow band spectral channel modules to provide very accurate, polarization-insensitive, stable measurements of earth albedo and lunar disk albedo. Optical degradation effects on calibration stability are eliminated through use of a common optical system for observations of the Sun, Earth, and Moon. The measurements from space would be traceable to SI units through preflight calibrations of radiance and irradiance at NIST's SIRCUS facility and the invariant optical system used in the sensor. Simultaneous measurements are made in multiple spectral channels covering the solar reflective wavelength range of 300 nm to 2.4 microns. The large dynamic range of signals is handled by use of single-element, highly-linear detectors, stable discrete electronic components, and a non imaging optical configuration. Up to 19 spectral modules can be mounted on a single-axis drive to give direct pointing at the Earth and at least once per orbit view of the Sun and Moon. By observing the Sun on every orbit, the most stringent stability requirements of the system are limited to short time periods. The invariant optical system for both radiance and irradiance measurements also give excellent transfer to-orbit SI traceability. Emerging instrumental requirements for remotely sensing tropospheric trace species have led to a rethinking by some of the paradigm for Systeme International d'Unites (SI) traceability of the spectral irradiance and radiance radiometric calibrations to spectral albedo (sr(exp -1)) which is not a SI unit. In the solar reflective wavelength region the spectral albedo calibrations are tied often to either the spectral albedo of a solar diffuser or the Moon

  12. Prototype of a primary calibration system for measurement of radon activity concentration.

    Science.gov (United States)

    Mostafa, M Y A; Vasyanovich, M; Zhukovsky, M

    2016-01-01

    To calibrate measurement devices for monitoring the activity concentration of (222)Rn in air, a prototype of a calibration facility is tested using a solid (226)Ra source and a high-purity germanium (HPGe) detector. An emanation box was mounted on the detector for online gamma measurements. Inside this box, a 32.8 kBq ±3% (226)Ra standard source was placed. An AlphaGUARD control radon monitor was connected to the emanation box with a pumping air system in an open flow mode as a reference monitor. The emanation coefficient of the source was controlled online by comparing the gamma activity of (214)Bi (Eγ=609.3 keV), progeny of (226)Ra, to that of the calibration source. A standard (137)Cs source, installed within the emanation box, was used as a reference for gamma spectroscopy using the HPGe detector, with a total systematic error of 4% and a random error less than 2%. The ratio between gamma measurements and AlphaGUARD was 0.94±0.4; which is within the 9% uncertainties of AlphaGUARD calibration. PMID:26490512

  13. The laser calibration system for the STACEE ground-based gamma ray detector

    CERN Document Server

    Hanna, D

    2002-01-01

    We describe the design and performance of the laser system used for calibration monitoring of components of the STACEE detector. STACEE is a ground based gamma ray detector which uses the heliostats of a solar power facility to collect and focus Cherenkov light onto a system of secondary optics and photomultiplier tubes. To monitor the gain and check the linearity and timing properties of the phototubes and associated electronics, a system based on a dye laser, neutral density filters and optical fibres has been developed. In this paper we describe the system and present some results from initial tests made with it.

  14. Accurate and automatic extrinsic calibration method for blade measurement system integrated by different optical sensors

    Science.gov (United States)

    He, Wantao; Li, Zhongwei; Zhong, Kai; Shi, Yusheng; Zhao, Can; Cheng, Xu

    2014-11-01

    Fast and precise 3D inspection system is in great demand in modern manufacturing processes. At present, the available sensors have their own pros and cons, and hardly exist an omnipotent sensor to handle the complex inspection task in an accurate and effective way. The prevailing solution is integrating multiple sensors and taking advantages of their strengths. For obtaining a holistic 3D profile, the data from different sensors should be registrated into a coherent coordinate system. However, some complex shape objects own thin wall feather such as blades, the ICP registration method would become unstable. Therefore, it is very important to calibrate the extrinsic parameters of each sensor in the integrated measurement system. This paper proposed an accurate and automatic extrinsic parameter calibration method for blade measurement system integrated by different optical sensors. In this system, fringe projection sensor (FPS) and conoscopic holography sensor (CHS) is integrated into a multi-axis motion platform, and the sensors can be optimally move to any desired position at the object's surface. In order to simple the calibration process, a special calibration artifact is designed according to the characteristics of the two sensors. An automatic registration procedure based on correlation and segmentation is used to realize the artifact datasets obtaining by FPS and CHS rough alignment without any manual operation and data pro-processing, and then the Generalized Gauss-Markoff model is used to estimate the optimization transformation parameters. The experiments show the measurement result of a blade, where several sampled patches are merged into one point cloud, and it verifies the performance of the proposed method.

  15. The Monitoring and Calibration Web Systems for the ATLAS Tile Calorimeter Data Quality Analysis

    Science.gov (United States)

    Sivolella, A.; Maidantchik, C.; Ferreira, F.

    2012-12-01

    The Tile Calorimeter (TileCal) is one of the ATLAS sub-detectors. The read-out is performed by about 10,000 PhotoMultiplier Tubes (PMTs). The signal of each PMT is digitized by an electronic channel. The Monitoring and Calibration Web System (MCWS) supports the data quality analysis of the electronic channels. This application was developed to assess the detector status and verify its performance. It can provide to the user the list of TileCal known problematic channels, that is stored in the ATLAS condition database (COOL DB). The bad channels list guides the data quality validator in identifying new problematic channels and is used in data reconstruction and the system allows to update the channels list directly in the COOL database. MCWS can generate summary results, such as eta-phi plots and comparative tables of the masked channels percentage. Regularly, during the LHC (Large Hadron Collider) shutdown a maintenance of the detector equipments is performed. When a channel is repaired, its calibration constants stored in the COOL database have to be updated. Additionally MCWS system manages the update of these calibration constants values in the COOL database. The MCWS has been used by the Tile community since 2008, during the commissioning phase, and was upgraded to comply with ATLAS operation specifications. Among its future developments, it is foreseen an integration of MCWS with the TileCal control Web system (DCS) in order to identify high voltage problems automatically.

  16. Accuracy improvement in a calibration test bench for accelerometers by a vision system

    Science.gov (United States)

    D'Emilia, Giulio; Di Gasbarro, David; Gaspari, Antonella; Natale, Emanuela

    2016-06-01

    A procedure is described in this paper for the accuracy improvement of calibration of low-cost accelerometers in a prototype rotary test bench, driven by a brushless servo-motor and operating in a low frequency range of vibrations (0 to 5 Hz). Vibration measurements by a vision system based on a low frequency camera have been carried out, in order to reduce the uncertainty of the real acceleration evaluation at the installation point of the sensor to be calibrated. A preliminary test device has been realized and operated in order to evaluate the metrological performances of the vision system, showing a satisfactory behavior if the uncertainty measurement is taken into account. A combination of suitable settings of the control parameters of the motion control system and of the information gained by the vision system allowed to fit the information about the reference acceleration at the installation point to the needs of the procedure for static and dynamic calibration of three-axis accelerometers.

  17. Calibration of a system to collect visible-light polarization data for classification of geosynchronous satellites

    Science.gov (United States)

    Speicher, Andy; Matin, Mohammad; Tippets, Roger; Chun, Francis

    2014-09-01

    In order to protect critical military and commercial space assets, the United States Space Surveillance Network must have the ability to positively identify and characterize all space objects. Unfortunately, positive identification and characterization of space objects is a manual and labor intensive process today since even large telescopes cannot provide resolved images of most space objects. The objective of this study was to calibrate a system to exploit the optical signature of unresolved geosynchronous satellite images by collecting polarization data in the visible wavelengths for the purpose of revealing discriminating features. These features may lead to positive identification or classification of each satellite. The system was calibrated with an algorithm and process that takes raw observation data from a two-channel polarimeter and converts it to Stokes parameters S0 and S1. This instrumentation is a new asset for the United States Air Force Academy (USAFA) Department of Physics and consists of one 20-inch Ritchey-Chretien telescope and a dual focal plane system fed with a polarizing beam splitter. This study calibrated the system and collected preliminary polarization data on five geosynchronous satellites to validate performance. Preliminary data revealed that each of the five satellites had a different polarization signature that could potentially lead to identification in future studies.

  18. Recent Developments and Status of the Langley Single Vector Balance Calibration System (SVS)

    Science.gov (United States)

    Jones, Shirley M.; Rhew, Ray D.

    2004-01-01

    The Langley Research Center (LaRC) Single Vector Balance Calibration System (SVS) was first introduced in 2000 by Peter Parker. The SVS combines the Design of Experiments (DOE) methodology with a novel load application system. Since that time three systems have been designed and developed with different load range capabilities (ranging from 2 pounds to 3,000 pounds). Approximately fifteen balances have been calibrated and their data compared to conventional techniques. This paper will present results of these comparisons, based on the mathematical models and accuracies, and discuss differences that were observed. In addition, changes in the implementation of the initial load schedules developed using DOE will be highlighted. One of the principles behind DOE is randomization. The initial loading schedules used to date have been randomized in the traditional DOE sense but not for repeat calibrations or experiments. Implementation of this randomization within blocks and its impact on data quality will be reviewed. Areas of potential future development will be presented which include changes in the centers to include loads with the force position system in the pure error estimates.

  19. In-flight calibration system for the INTEGRAL x-ray monitor

    DEFF Research Database (Denmark)

    Costa, E.; Feroci, M.; Barbanera, L.;

    1996-01-01

    JEM-X is the x-ray monitor serving the two gamma-ray experiments imager and spectrometer onboard the ESA's INTEGRAL satellite. Due to the intrinsic weakness of the celestial sources in the gamma energy range they will need very long integration times. During these long pointings JEM-X will be able...... to detect very small variations on most x-ray sources, but only if accurately calibrated. The in- flight calibration system of the JEM-X experiment is devoted to measure the response of the detection chain (detector plus electronics) in a small set of positions and energies. The data from this system...... of Amptek Cool-X15 X-ray generators. The latter is a novel product, based on a pyroelectric crystal used to generate energetic electrons that produce fluorescence lines by hitting a metallic target. We plan to use the four low intensity radioactive sources for monitoring the four independent anode chains...

  20. Conceptual Model Structure Identification and Calibration for River and Sewer Systems

    OpenAIRE

    Wolfs, Vincent

    2016-01-01

    Keywords: river; sewer; integral water management; conceptual modelling; water quantity modelling; model structure identification and calibration; software Water management is constantly evolving. Trends, such as population growth, urbanization and climate change, pose new challenges to water management. Risks and uncertainties have to be taken into account in order to develop strategies that remain cost-effective on the long term. Water systems consist of different subsystems and interact...

  1. Light pulse laser source for calibration of multi-channel photorecording systems

    International Nuclear Information System (INIS)

    A source of nanosecond light flashes based on nitrogen laser with transverse discharge simUlating particle passage through radiation coUnters is described. The source is intended for amplitude calibration of multichan.nel systems with number of channels > or approximately 103. Heterogeneity of light signal in all the channels is approximately 10%. Amplitude scattering of pulses is +- 2.5% (half-width by half-height) at pulse duration of approximately 5 ns (on half of amplitude)

  2. Drive system alignment calibration of a microgravity drop tower of novel design

    Science.gov (United States)

    Trunins, J.; Osborne, B. P.; Augousti, A.

    2013-06-01

    We report here the calibration of the drive system of a new scientific facility for production of microgravity, operating on a novel design of electromagnetically driven platform. The construction achieves the design specification of alignment of the guide rails to better than 0.254mm across the entire guide rail height of 8m, despite a small lean to the right (within tolerance) and it was noted that this alignment is improved by the presence of the trolley that carries the platform.

  3. Temporal Analysis and Automatic Calibration of the Velodyne HDL-32E LiDAR System

    Science.gov (United States)

    Chan, T. O.; Lichti, D. D.; Belton, D.

    2013-10-01

    At the end of the first quarter of 2012, more than 600 Velodyne LiDAR systems had been sold worldwide for various robotic and high-accuracy survey applications. The ultra-compact Velodyne HDL-32E LiDAR has become a predominant sensor for many applications that require lower sensor size/weight and cost. For high accuracy applications, cost-effective calibration methods with minimal manual intervention are always desired by users. However, the calibrations are complicated by the Velodyne LiDAR's narrow vertical field of view and the very highly time-variant nature of its measurements. In the paper, the temporal stability of the HDL-32E is first analysed as the motivation for developing a new, automated calibration method. This is followed by a detailed description of the calibration method that is driven by a novel segmentation method for extracting vertical cylindrical features from the Velodyne point clouds. The proposed segmentation method utilizes the Velodyne point cloud's slice-like nature and first decomposes the point clouds into 2D layers. Then the layers are treated as 2D images and are processed with the Generalized Hough Transform which extracts the points distributed in circular patterns from the point cloud layers. Subsequently, the vertical cylindrical features can be readily extracted from the whole point clouds based on the previously extracted points. The points are passed to the calibration that estimates the cylinder parameters and the LiDAR's additional parameters simultaneously by constraining the segmented points to fit to the cylindrical geometric model in such a way the weighted sum of the adjustment residuals are minimized. The proposed calibration is highly automatic and this allows end users to obtain the time-variant additional parameters instantly and frequently whenever there are vertical cylindrical features presenting in scenes. The methods were verified with two different real datasets, and the results suggest that up to 78

  4. Calibration of a system for measuring low air flow velocity in a wind tunnel

    Science.gov (United States)

    Krach, Andrzej; Kruczkowski, Janusz

    2016-08-01

    This article presents the calibration of a system for measuring air flow velocity in a wind tunnel with a multiple-hole orifice. The comparative method was applied for the calibration. The method consists in equalising the air flow velocity in a test section of the tunnel with that of the hot-wire anemometer probe which should then read zero value. The hot-wire anemometer probe moves reciprocally in the tunnel test section with a constant velocity, aligned and opposite to the air velocity. Air velocity in the tunnel test section is adjusted so that the minimum values of a periodic hot-wire anemometer signal displayed on an oscilloscope screen reach the lowest position (the minimum method). A sinusoidal component can be superimposed to the probe constant velocity. Then, the air flow velocity in the tunnel test section is adjusted so that, when the probe moves in the direction of air flow, only the second harmonic of the periodically variable velocity superimposed on the constant velocity (second harmonic method) remains at the output of the low-pass filter to which the hot-wire anemometer signal, displayed on the oscilloscope screen, is supplied. The velocity of the uniform motion of the hot-wire anemometer probe is measured with a magnetic linear encoder. The calibration of the system for the measurement of low air velocities in the wind tunnel was performed in the following steps: 1. Calibration of the linear encoder for the measurement of the uniform motion velocity of the hot-wire anemometer probe in the test section of the tunnel. 2. Calibration of the system for measurement of low air velocities with a multiple-hole orifice for the velocities of 0.1 and 0.25 m s‑1: - (a) measurement of the probe movement velocity setting; - (b) measurement of air velocity in the tunnel test section with comparison according to the second harmonic method; - (c) measurement of air velocity in the tunnel with comparison according to the minimum method. The calibration

  5. The upgrade of the laser calibration system for the ATLAS hadron calorimeter TileCal

    CERN Document Server

    Spalla, Margherita; The ATLAS collaboration

    2014-01-01

    The Tile Calorimeter (TileCal), the central section of the hadronic calorimeter of the ATLAS experiment, is a key detector component to detect hadrons, jets and taus and to measure the missing transverse energy. TileCal is built of steel and scintillating tiles coupled to optical fibers and read‐out by photomultipliers (PMT). The performance of TileCal relies on a continuous, high resolution calibration of the individual response of the 10,000 channels forming the detector. The calibration is based on a three level architecture: a charge injection system used to monitor the full electronics chain including front-end amplifiers, digitizers and event builder blocks for each individual channel; a distributed optical system using laser pulses to excite all PMTs; and a mobile Cesium radiative source which is driven through the detector cell floating inside a pipe system. This architecture allows for a cascade calibration of the electronics, of the PMT and electronics, and of full chain including the active detec...

  6. Photometric Calibration and Image Stitching for a Large Field of View Multi-Camera System.

    Science.gov (United States)

    Lu, Yu; Wang, Keyi; Fan, Gongshu

    2016-04-11

    A new compact large field of view (FOV) multi-camera system is introduced. The camera is based on seven tiny complementary metal-oxide-semiconductor sensor modules covering over 160° × 160° FOV. Although image stitching has been studied extensively, sensor and lens differences have not been considered in previous multi-camera devices. In this study, we have calibrated the photometric characteristics of the multi-camera device. Lenses were not mounted on the sensor in the process of radiometric response calibration to eliminate the influence of the focusing effect of uniform light from an integrating sphere. Linearity range of the radiometric response, non-linearity response characteristics, sensitivity, and dark current of the camera response function are presented. The R, G, and B channels have different responses for the same illuminance. Vignetting artifact patterns have been tested. The actual luminance of the object is retrieved by sensor calibration results, and is used to blend images to make panoramas reflect the objective luminance more objectively. This compensates for the limitation of stitching images that are more realistic only through the smoothing method. The dynamic range limitation of can be resolved by using multiple cameras that cover a large field of view instead of a single image sensor with a wide-angle lens. The dynamic range is expanded by 48-fold in this system. We can obtain seven images in one shot with this multi-camera system, at 13 frames per second.

  7. Photometric Calibration and Image Stitching for a Large Field of View Multi-Camera System

    Directory of Open Access Journals (Sweden)

    Yu Lu

    2016-04-01

    Full Text Available A new compact large field of view (FOV multi-camera system is introduced. The camera is based on seven tiny complementary metal-oxide-semiconductor sensor modules covering over 160° × 160° FOV. Although image stitching has been studied extensively, sensor and lens differences have not been considered in previous multi-camera devices. In this study, we have calibrated the photometric characteristics of the multi-camera device. Lenses were not mounted on the sensor in the process of radiometric response calibration to eliminate the influence of the focusing effect of uniform light from an integrating sphere. Linearity range of the radiometric response, non-linearity response characteristics, sensitivity, and dark current of the camera response function are presented. The R, G, and B channels have different responses for the same illuminance. Vignetting artifact patterns have been tested. The actual luminance of the object is retrieved by sensor calibration results, and is used to blend images to make panoramas reflect the objective luminance more objectively. This compensates for the limitation of stitching images that are more realistic only through the smoothing method. The dynamic range limitation of can be resolved by using multiple cameras that cover a large field of view instead of a single image sensor with a wide-angle lens. The dynamic range is expanded by 48-fold in this system. We can obtain seven images in one shot with this multi-camera system, at 13 frames per second.

  8. A laser diode based system for calibration of fast time-of-flight detectors

    CERN Document Server

    Bonesini, M; deBari, A; Rossella, M

    2016-01-01

    A system based on commercially available items, such as a laser diode, emitting in the visible range $\\sim 400$ nm,and multimode fiber patches, fused fiber splitters and optical switches may be assembled,for time calibration of multi-channels time-of-flight (TOF) detectors with photomultipliers' (PMTs') readout. As available laser diode sources have unfortunately limited peak power, the main experimental problem is the tight light power budget of such a system. In addition, while the technology for fused fiber splitters is common in the Telecom wavelength range ($\\lambda \\sim 850, 1300-1500$ nm), it is not easily available in the visible one. Therefore, extensive laboratory tests had to be done on purpose, to qualify the used optical components, and a full scale timing calibration prototype was built. Obtained results show that with such a system, a calibration resolution ($\\sigma$) in the range 20-30 ps may be within reach. Therefore, fast multi-channels TOF detectors, with timing resolutions in the range 50...

  9. Short Tandem Repeat DNA Internet Database

    Science.gov (United States)

    SRD 130 Short Tandem Repeat DNA Internet Database (Web, free access)   Short Tandem Repeat DNA Internet Database is intended to benefit research and application of short tandem repeat DNA markers for human identity testing. Facts and sequence information on each STR system, population data, commonly used multiplex STR systems, PCR primers and conditions, and a review of various technologies for analysis of STR alleles have been included.

  10. A Calibration Method Based on Linear InGaAs in Fiber Grating Sensors Interrogation System

    Institute of Scientific and Technical Information of China (English)

    TAO Jun; ZHANG Xia

    2009-01-01

    In accordance with the characteristics of wavelength shift detection in fiber grating sensor interrogation system, the wavelength interrogation system which uses linear InGaAs as the spectrum receiver is proposed. Orientation of optic spectrum line affects the silt of volume phase grating and size of InGaAs photosensitive unit, thus the calibration method is needed. Based on an analysis of InGaAs imaging model, least square curve fitting method is proposed to detect spectrum wavelength and InGaAs photosensitive unit position. The experimental results show that the methods are effective and the demodulation system precision is improved.

  11. Spinning rotor gauge based vacuum gauge calibration system at the Institute for Plasma Research (IPR)

    International Nuclear Information System (INIS)

    The Steady-state Superconducting Tokamak (SST-1) is an indigenously built medium sized fusion device at IPR designed for plasma duration of 1000 seconds. It consists of two large vacuum chambers – Vacuum Vessel (16 m3) and Cryostat (39 m3) which will be pumped to UHV and HV pressures respectively using a set of turbo molecular pumps, Cryo-pumps and Roots pumps. The total as well as the partial pressure measurement in these chambers will be carried out using a set of Pirani gauges, Bayard Alpert type gauges, Capacitance manometers and Residual Gas Analyzers (RGA). A reliable and accurate pressure measurement is essential for successful operation of SST-1 machine. For this purpose a gauge calibration system is set up in SST-1 Vacuum laboratory based on Spinning Rotor Gauge which can measure absolute pressure in the range 1.0 mbar to 1.0 × 10−7 mbar. This system is designed to calibrate up to five gauges simultaneously for different gases in different operating pressure ranges of the gauges. This paper discusses the experimental set-up and the procedure adopted for the calibration of such vacuum gauges.

  12. Automatic Laser Interferometer And Vision Measurement System For Stripe Rod Calibration

    Directory of Open Access Journals (Sweden)

    Zhao Min

    2015-12-01

    Full Text Available In order to calibrate the stripe precision of a leveling rod, an automatic laser interferometer and a vision measurement system were designed by Xi’an University of Technology in China. The rod was driven by a closed-loop control and the data were collected at the stop state to ensure precision. The laser interferometer provided not only the long distance data but also a position feedback signal in the automatic control loop. CCD camera and a vision measurement method were used to inspect the stripe edge position and defect. A pixel-equivalent self-calibration method was designed to improve precision. ROI (regions of interest method and an outline tracing method were designed to quickly extract multiple stripe edges. A combination of the image data with the interferometer data reduces control difficulty and ensures the measurement accuracy. The vision measurement method reached sub-pixel precision and the defective edges were reported. The system can automatically calibrate a stripe leveling rod with a high degree of efficiency and precision.

  13. Numerical analysis of the first static calibration of the RSRA helicopter active-isolator rotor balance system

    Science.gov (United States)

    Acree, C. W., Jr.

    1985-01-01

    The helicopter version of the Rotor Systems Research Aircraft (RSRA) is designed to make simultaneous measurements of all rotor forces and moments in a manner analogous to a wind-tunnel balance. Loads are measured by a combination of load cells, strain gages, and hydropneumatic active isolators with built-in pressure gages. Complete evaluation of system performance requires calibration of the rotor force- and moment-measurement system when installed in the aircraft. Derivations of calibration corrections for various combinations of calibration data are discussed.

  14. Calibration of laser scanner and camera fusion system for intelligent vehicles using Nelder-Mead optimization

    Science.gov (United States)

    Osgood, Thomas J.; Huang, Yingping

    2013-03-01

    A novel method is presented here for the calibration of a sensor fusion system for intelligent vehicles. In this example, the sensors are a camera and a laser scanner which observe the same scene from different viewpoints. The method employs the Nelder-Mead direct search algorithm to minimize the sum of squared errors between the image coordinates and the re-projected laser data by iteratively adjusting and improving the calibration parameters. The method is applied to a real set of data collected from a test vehicle. Using only 11 well-spaced target points observable by each sensor, 12 intrinsic and extrinsic parameters indicating the position relationship between the sensors can be estimated to give an accurate projection. Experiments show that the method can project the laser points onto the image plane with an average error of 1.01 pixels (1.51 pixels worst case).

  15. Object Occlusion Detection Using Automatic Camera Calibration for a Wide-Area Video Surveillance System.

    Science.gov (United States)

    Jung, Jaehoon; Yoon, Inhye; Paik, Joonki

    2016-01-01

    This paper presents an object occlusion detection algorithm using object depth information that is estimated by automatic camera calibration. The object occlusion problem is a major factor to degrade the performance of object tracking and recognition. To detect an object occlusion, the proposed algorithm consists of three steps: (i) automatic camera calibration using both moving objects and a background structure; (ii) object depth estimation; and (iii) detection of occluded regions. The proposed algorithm estimates the depth of the object without extra sensors but with a generic red, green and blue (RGB) camera. As a result, the proposed algorithm can be applied to improve the performance of object tracking and object recognition algorithms for video surveillance systems. PMID:27347978

  16. Object Occlusion Detection Using Automatic Camera Calibration for a Wide-Area Video Surveillance System

    Directory of Open Access Journals (Sweden)

    Jaehoon Jung

    2016-06-01

    Full Text Available This paper presents an object occlusion detection algorithm using object depth information that is estimated by automatic camera calibration. The object occlusion problem is a major factor to degrade the performance of object tracking and recognition. To detect an object occlusion, the proposed algorithm consists of three steps: (i automatic camera calibration using both moving objects and a background structure; (ii object depth estimation; and (iii detection of occluded regions. The proposed algorithm estimates the depth of the object without extra sensors but with a generic red, green and blue (RGB camera. As a result, the proposed algorithm can be applied to improve the performance of object tracking and object recognition algorithms for video surveillance systems.

  17. Optical configuration optimization and calibration for the POINT system on EAST

    Science.gov (United States)

    Zou, Z. Y.; Liu, H. Q.; Li, W. M.; Lian, H.; Wang, S. X.; Yao, Y.; Lan, T.; Zeng, L.; Jie, Y. X.

    2016-11-01

    Calibration of the polarimeter system is one of the key elements to determine the overall measurement accuracy. The anisotropic reflection and transmission properties of the mesh beam splitters can easily distort the polarization state of the circularly polarized beams. Using a rotating crystal quartz λ/2-waveplate to replace the plasma can effectively allow us to obtain the ratio of the measured Faraday rotation angle to the known rotation angle of the waveplate. This ratio is used to estimate the calibration factor for each chord to be accurately determined and help to minimize distortions introduced by the wire-mesh beam splitters. With the novel configuration optimization, the distortion of polarization state is effectively eliminated.

  18. Calibration of laser scanner and camera fusion system for intelligent vehicles using Nelder–Mead optimization

    International Nuclear Information System (INIS)

    A novel method is presented here for the calibration of a sensor fusion system for intelligent vehicles. In this example, the sensors are a camera and a laser scanner which observe the same scene from different viewpoints. The method employs the Nelder–Mead direct search algorithm to minimize the sum of squared errors between the image coordinates and the re-projected laser data by iteratively adjusting and improving the calibration parameters. The method is applied to a real set of data collected from a test vehicle. Using only 11 well-spaced target points observable by each sensor, 12 intrinsic and extrinsic parameters indicating the position relationship between the sensors can be estimated to give an accurate projection. Experiments show that the method can project the laser points onto the image plane with an average error of 1.01 pixels (1.51 pixels worst case). (paper)

  19. Object Occlusion Detection Using Automatic Camera Calibration for a Wide-Area Video Surveillance System.

    Science.gov (United States)

    Jung, Jaehoon; Yoon, Inhye; Paik, Joonki

    2016-06-25

    This paper presents an object occlusion detection algorithm using object depth information that is estimated by automatic camera calibration. The object occlusion problem is a major factor to degrade the performance of object tracking and recognition. To detect an object occlusion, the proposed algorithm consists of three steps: (i) automatic camera calibration using both moving objects and a background structure; (ii) object depth estimation; and (iii) detection of occluded regions. The proposed algorithm estimates the depth of the object without extra sensors but with a generic red, green and blue (RGB) camera. As a result, the proposed algorithm can be applied to improve the performance of object tracking and object recognition algorithms for video surveillance systems.

  20. Organization and performance of the neutral beam system for the Tandem Mirror Experiment-Upgrade (TMX-U)

    International Nuclear Information System (INIS)

    The Tandem Mirror Experiment-Upgrade (TMX-U) at Lawrence Livermore National Laboratory (LLNL) uses 24 neutral-beam injectors to heat and fuel the experimental plasmas. This system is unique because TMX-U operates four times more injectors than any other fusion experiment. These injectors deliver an average of 50 A (accel) at 17 keV for 75 ms. Source conditioning time has been reduced to approximately four days for the entire system after extended machine air cycles. TMX-U is also unique because it has 35 usable injector assemblies for the 24 power systems. This quantity of injectors makes possible the development of new hardware and injector modifications, and the reconditioning of damaged sources without affecting machine operation. Efficient operation of a system of this size requires coordinated interaction between the injector service groups and the physics organization. We describe the current state of TMX-U performance and the aspects of group interaction essential to a project of this size

  1. Supercal: Cross-Calibration of Multiple Photometric Systems to Improve Cosmological Measurements with Type Ia Supernovae

    CERN Document Server

    Scolnic, D; Riess, A G; Rest, A; Schlafly, E; Foley, R J; Finkbeiner, D; Tang, C; Burgett, W S; Chambers, K C; Draper, P W; Hodapp, K W; Huber, M E; Kaiser, N; Kudritzki, R P; Magnier, E A; Metcalfe, N; Stubbs, C W

    2015-01-01

    Current cosmological analyses which use Type Ia supernova (SN Ia) observations combine SN samples to expand the redshift range beyond that of a single sample and increase the overall sample size. The inhomogeneous photometric calibration between different SN samples is one of the largest systematic uncertainties of the cosmological parameter estimation. To place these different samples on a single system, analyses currently use observations of a small sample of very bright flux standards on the $HST$ system. We propose a complementary method, called `Supercal', in which we use measurements of secondary standards in each system, compare these to measurements of the same stars in the Pan-STARRS1 (PS1) system, and determine offsets for each system relative to PS1, placing all SN observations on a single, consistent photometric system. PS1 has observed $3\\pi$ of the sky and has a relative calibration of better than 5 mmag (for $\\sim15system. We use this process t...

  2. Generic precise augmented reality guiding system and its calibration method based on 3D virtual model.

    Science.gov (United States)

    Liu, Miao; Yang, Shourui; Wang, Zhangying; Huang, Shujun; Liu, Yue; Niu, Zhenqi; Zhang, Xiaoxuan; Zhu, Jigui; Zhang, Zonghua

    2016-05-30

    Augmented reality system can be applied to provide precise guidance for various kinds of manual works. The adaptability and guiding accuracy of such systems are decided by the computational model and the corresponding calibration method. In this paper, a novel type of augmented reality guiding system and the corresponding designing scheme are proposed. Guided by external positioning equipment, the proposed system can achieve high relative indication accuracy in a large working space. Meanwhile, the proposed system is realized with a digital projector and the general back projection model is derived with geometry relationship between digitized 3D model and the projector in free space. The corresponding calibration method is also designed for the proposed system to obtain the parameters of projector. To validate the proposed back projection model, the coordinate data collected by a 3D positioning equipment is used to calculate and optimize the extrinsic parameters. The final projecting indication accuracy of the system is verified with subpixel pattern projecting technique. PMID:27410124

  3. Calibration method of the time synchronization error of many data acquisition nodes in the chained system

    Science.gov (United States)

    Jiang, Jia-jia; Duan, Fa-jie; Chen, Jin; Zhang, Chao; Wang, Kai; Chang, Zong-jie

    2012-08-01

    Time synchronization is very important in a distributed chained seismic acquisition system with a large number of data acquisition nodes (DANs). The time synchronization error has two causes. On the one hand, there is a large accumulated propagation delay when commands propagate from the analysis and control system to multiple distant DANs, which makes it impossible for different DANs to receive the same command synchronously. Unfortunately, the propagation delay of commands (PDCs) varies in different application environments. On the other hand, the phase jitter of both the master clock and the clock recovery phase-locked loop, which is designed to extract the timing signal, may also cause the time synchronization error. In this paper, in order to achieve accurate time synchronization, a novel calibration method is proposed which can align the PDCs of all of the DANs in real time and overcome the time synchronization error caused by the phase jitter. Firstly, we give a quantitative analysis of the time synchronization error caused by both the PDCs and the phase jitter. Secondly, we propose a back and forth model (BFM) and a transmission delay measurement method (TDMM) to overcome these difficulties. Furthermore, the BFM is designed as the hardware configuration to measure the PDCs and calibrate the time synchronization error. The TDMM is used to measure the PDCs accurately. Thirdly, in order to overcome the time synchronization error caused by the phase jitter, a compression and mapping algorithm (CMA) is presented. Finally, based on the proposed BFM, TDMM and CMA, a united calibration algorithm is developed to overcome the time synchronization error caused by both the PDCs and the phase jitter. The simulation experiment results show the effectiveness of the calibration method proposed in this paper.

  4. New data concerning the efficiency calibration of a drum waste assay system

    International Nuclear Information System (INIS)

    The study is focused on the efficiency calibration of a gamma spectroscopy system for drum waste assay.The measurement of a radioactive drum waste is usually difficult because of its large volume, the varied distribution of the waste within the drum and its high self attenuation.To solve this problems, a complex calibration of the system is required. For this purpose, a calibration drum provided with seven tubes, placed at different distances from its center was used, the rest of the drum being filled with Portland cement. For the efficiency determination of a uniformly distributed source, a linear source of 152 Eu was used.The linear calibration source was introduced successively inside the seven tubes, the gamma spectra being recorded while the drum was translated and simultaneously rotated. Using the GENIE-PC software, the gamma-spectra were analyzed and the detection efficiencies for shell-sources were obtained. Using this efficiencies, the total response of the detector and the detection efficiency appropriate to a uniform volume source were calculated. For the efficiency determination of a non-homogenous source, additional measurements in the following geometries were made. First, with a 152 Eu point source placed in front of the detector, measured in all seven tubes, the drum being only rotated. Second, with the linear source of 152 Eu placed in front of the detector, measured in all seven tubes, only the drum being rotated. For each position the gamma spectra was recorded and the detection efficiency was calculated.The obtained values for efficiency were verified using GESPECOR software, which has been developed for the computation of the efficiency of Ge detectors for a wide class of measurement configurations, using Monte-Carlo method. (authors)

  5. Efficacy of calibration function by CMOS digital system software for working length estimation

    Directory of Open Access Journals (Sweden)

    Mohtavipour Seyedeh Tahereh

    2016-07-01

    Full Text Available Background and Aims: Estimating the canal length is essential for reaching to a proper endodontic treatment. Any error and miscalculation in estimation of the working length, especially in curved canals, can result in complication during and after root canal therapy. The introduction of digital radiography has enabled us to measure curved canal length. The purpose of this study was to evaluate the calibration tool of Complementary Metal Oxide Semiconductor (CMOS digital system in estimation of working length. Materials and Methods: In this in-vitro study, 80 extracted molar teeth were selected and randomly divided into three groups based on angle and radius of canal curvature. A 5 mm orthodontic wire was placed on the lateral surface of the root. Conventional radiographs were taken after insertion of endodontic file in the apical third of root canals. Radiographic images were scanned and imported to the software of CMOS digital system. Two observers estimated the file lengths with and without using calibration tool of digital measurement software. The correlation between observers was evaluated and then data were analyzed using Paired T-test with 95% confidence. Results: Overall agreement between observers was good. There was no significant difference between the mean values of calibrated measurement and true file length in the basis of canal curves (P>0.001. However, there was significant difference between the mean values of uncalibrated measurement and true file length in the basis of canal curvature (P<0.001. Conclusion: The calibrated measurement of file length was more accurate than that of the uncalibrated file length measurement.

  6. System for calibration of instruments of x-ray measurement (CIR-X) applying the PGCS

    International Nuclear Information System (INIS)

    The Department of Metrology of Ionizing Radiations of the ININ carries out calibration of instruments for X-ray measurement that determine the operation parameters in X-ray diagnostic machines of the health and private sectors. To facilitate this task, the Department of Automation and Instrumentation developed a system for acquisition and signals processing coming from a reference voltage divider with traceability at NIST that is connected directly to the X-rays tube. The system is integrated by the X-ray unit, the X-ray measurement equipment Dynalizer IIIU of RADCAL, a data acquisition card, a personal computer and the acquisition software and signals processing. (Author)

  7. Maximum-Likelihood Calibration of an X-ray Computed Tomography System

    OpenAIRE

    Moore, Jared W.; Van Holen, Roel; Barrett, Harrison H.; Furenlid, Lars R.

    2010-01-01

    We present a maximum-likelihood (ML) method for calibrating the geometrical parameters of an x-ray computed tomography (CT) system. This method makes use of the full image data and not a reduced set of data. This algorithm is particularly useful for CT systems that change their geometry during the CT acquisition, such as an adaptive CT scan. Our ML search method uses a contracting-grid algorithm that does not require initial starting values to perform its estimate, thus avoiding problems asso...

  8. Multi-Point Thomson Scattering System Calibration and Measurements on HBT-EP

    Science.gov (United States)

    Donald, G. V.; Levesque, J. P.; Stoafer, C. C.; Mauel, M. E.

    2015-11-01

    A Thomson scattering (TS) system has been successfully installed and calibrated for diagnostics of HBT-EP. The TS system provides three spatial point measurements and has significantly improved upon the previous single point system. Analysis of Rayleigh Scattering was performed for an absolute density calibration of the TS system. Energy fluctuations in the output pulse from the Nd:YAG laser are individually recorded and accounted for using an integrating sphere and photodetector. Te and ne profiles have been investigated for varying wall configuration changes, including insertion of ferritic wall elements. We report our results, for the three spatial points, and measurements of the Te and ne evolution through typical HBT-EP discharges. The three fiber bundle system will be upgraded within the next grant period to allow measurement of ten spatial points. The ten point system will enhance our equilibrium reconstruction capability, improve stability analysis of the HBT-EP discharges, and allow for further understanding of the plasma characteristics during resistive wall mode (RWM) activity and active control experiments. Supported by U.S. DOE Grant DE-FG02-86ER53222.

  9. X-ray detection system development for tandem mirror experiment upgrade (TMX-U): hardware and software

    International Nuclear Information System (INIS)

    This x-ray detection system measures the electron Bremsstrahlung spectrum from the Tandem Mirror Experiment-Upgrade (TMX-U). From this spectrum, we can calculate the electron temperature. The low energy portion of the spectrum (0.5 to 40 keV) is measured by a liquid-nitrogen-cooled, lithium-drifted silicon detector. The higher energy spectrometer uses an intrinsic germanium detector to accommodate the 100 to 200 keV spectra. The system proceeds as follows. The preamplified detector signals are digitized by a high-speed A-to-D converter located in a Computer Automated Measurement and Control (CAMAC) crate. The data is then stored in a histogramming memory via a data router. The CAMAC crate interfaces with a local desktop computer or the main data acquisition computer that stores the data. The software sets up the modules, acquires the energy spectra (with sample times as short as 2 ms) and plots it. Up to 40 time-resolved spectra are available during one plasma cycle. The actual module configuration, CAMAC interfacing and software that runs the system are the subjects of this paper

  10. Massively parallel sequencing of short tandem repeats-Population data and mixture analysis results for the PowerSeq™ system.

    Science.gov (United States)

    van der Gaag, Kristiaan J; de Leeuw, Rick H; Hoogenboom, Jerry; Patel, Jaynish; Storts, Douglas R; Laros, Jeroen F J; de Knijff, Peter

    2016-09-01

    Current forensic DNA analysis predominantly involves identification of human donors by analysis of short tandem repeats (STRs) using Capillary Electrophoresis (CE). Recent developments in Massively Parallel Sequencing (MPS) technologies offer new possibilities in analysis of STRs since they might overcome some of the limitations of CE analysis. In this study 17 STRs and Amelogenin were sequenced in high coverage using a prototype version of the Promega PowerSeq™ system for 297 population samples from the Netherlands, Nepal, Bhutan and Central African Pygmies. In addition, 45 two-person mixtures with different minor contributions down to 1% were analysed to investigate the performance of this system for mixed samples. Regarding fragment length, complete concordance between the MPS and CE-based data was found, marking the reliability of MPS PowerSeq™ system. As expected, MPS presented a broader allele range and higher power of discrimination and exclusion rate. The high coverage sequencing data were used to determine stutter characteristics for all loci and stutter ratios were compared to CE data. The separation of alleles with the same length but exhibiting different stutter ratios lowers the overall variation in stutter ratio and helps in differentiation of stutters from genuine alleles in mixed samples. All alleles of the minor contributors were detected in the sequence reads even for the 1% contributions, but analysis of mixtures below 5% without prior information of the mixture ratio is complicated by PCR and sequencing artefacts. PMID:27347657

  11. Generating markers based on biotic stress of protein system in and tandem repeats sequence for Aquilaria sp

    International Nuclear Information System (INIS)

    Aquilaria sp. belongs to the Thymelaeaceae family and is well distributed in Asia region. The species has multipurpose use from root to shoot and is an economically important crop, which generates wide interest in understanding genetic diversity of the species. Knowledge on DNA-based markers has become a prerequisite for more effective application of molecular marker techniques in breeding and mapping programs. In this work, both targeted genes and tandem repeat sequences were used for DNA fingerprinting in Aquilaria sp. A total of 100 ISSR (inter simple sequence repeat) primers and 50 combination pairs of specific primers derived from conserved region of a specific protein known as system in were optimized. 38 ISSR primers were found affirmative for polymorphism evaluation study and were generated from both specific and degenerate ISSR primers. And one utmost combination of system in primers showed significant results in distinguishing the Aquilaria sp. In conclusion, polymorphism derived from ISSR profiling and targeted stress genes of protein system in proved as a powerful approach for identification and molecular classification of Aquilaria sp. which will be useful for diversification in identifying any mutant lines derived from nature. (author)

  12. Calibration of muon reconstruction algorithms using an external muon tracking system at the Sudbury Neutrino Observatory

    International Nuclear Information System (INIS)

    To help constrain the algorithms used in reconstructing high-energy muon events incident on the Sudbury Neutrino Observatory (SNO), a muon tracking system was installed. The system consisted of four planes of wire chambers, which were triggered by scintillator panels. The system was integrated with SNO's main data acquisition system and took data for a total of 95 live days. Using cosmic-ray events reconstructed in both the wire chambers and in SNO's water Cherenkov detector, the external muon tracking system was able to constrain the uncertainty on the muon direction to better than 0.6o. - Highlights: → This paper describes a novel technique for calibrating tracking algorithms. → The experimental accuracy achieved by this system was better than 1o. → The principle behind the technique can be used in future underground experiments.

  13. Monte Carlo studies and optimization for the calibration system of the GERDA experiment

    Science.gov (United States)

    Baudis, L.; Ferella, A. D.; Froborg, F.; Tarka, M.

    2013-11-01

    The GERmanium Detector Array, GERDA, searches for neutrinoless double β decay in 76Ge using bare high-purity germanium detectors submerged in liquid argon. For the calibration of these detectors γ emitting sources have to be lowered from their parking position on the top of the cryostat over more than 5 m down to the germanium crystals. With the help of Monte Carlo simulations, the relevant parameters of the calibration system were determined. It was found that three 228Th sources with an activity of 20 kBq each at two different vertical positions will be necessary to reach sufficient statistics in all detectors in less than 4 h of calibration time. These sources will contribute to the background of the experiment with a total of (1.07±0.04(stat)-0.19+0.13(sys))×10-4 cts/(keV kg yr)) when shielded from below with 6 cm of tantalum in the parking position.

  14. Monte Carlo studies and optimization for the calibration system of the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Baudis, L. [Physics Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zürich (Switzerland); Ferella, A.D. [Physics Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zürich (Switzerland); INFN Laboratori Nazionali del Gran Sasso, 67010 Assergi (Italy); Froborg, F., E-mail: francis@froborg.de [Physics Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zürich (Switzerland); Tarka, M. [Physics Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zürich (Switzerland); Physics Department, University of Illinois, 1110 West Green Street, Urbana, IL 61801 (United States)

    2013-11-21

    The GERmanium Detector Array, GERDA, searches for neutrinoless double β decay in {sup 76}Ge using bare high-purity germanium detectors submerged in liquid argon. For the calibration of these detectors γ emitting sources have to be lowered from their parking position on the top of the cryostat over more than 5 m down to the germanium crystals. With the help of Monte Carlo simulations, the relevant parameters of the calibration system were determined. It was found that three {sup 228}Th sources with an activity of 20 kBq each at two different vertical positions will be necessary to reach sufficient statistics in all detectors in less than 4 h of calibration time. These sources will contribute to the background of the experiment with a total of (1.07±0.04(stat){sub −0.19}{sup +0.13}(sys))×10{sup −4}cts/(keVkgyr)) when shielded from below with 6 cm of tantalum in the parking position.

  15. A vision-based self-calibration method for robotic visual inspection systems.

    Science.gov (United States)

    Yin, Shibin; Ren, Yongjie; Zhu, Jigui; Yang, Shourui; Ye, Shenghua

    2013-01-01

    A vision-based robot self-calibration method is proposed in this paper to evaluate the kinematic parameter errors of a robot using a visual sensor mounted on its end-effector. This approach could be performed in the industrial field without external, expensive apparatus or an elaborate setup. A robot Tool Center Point (TCP) is defined in the structural model of a line-structured laser sensor, and aligned to a reference point fixed in the robot workspace. A mathematical model is established to formulate the misalignment errors with kinematic parameter errors and TCP position errors. Based on the fixed point constraints, the kinematic parameter errors and TCP position errors are identified with an iterative algorithm. Compared to the conventional methods, this proposed method eliminates the need for a robot-based-frame and hand-to-eye calibrations, shortens the error propagation chain, and makes the calibration process more accurate and convenient. A validation experiment is performed on an ABB IRB2400 robot. An optimal configuration on the number and distribution of fixed points in the robot workspace is obtained based on the experimental results. Comparative experiments reveal that there is a significant improvement of the measuring accuracy of the robotic visual inspection system. PMID:24300597

  16. Wavelength calibration of the charge exchange recombination spectroscopy system on the DIII-D tokamak

    International Nuclear Information System (INIS)

    A wavelength calibration of all the detectors on the charge exchange recombination spectroscopy (CER) system is performed after every plasma discharge on the DIII-D tokamak. This is done to insure that the rest wavelength position of the C VI 5290.5 angstrom charge exchange line on the detector is accurately known so that the Doppler shift of the spectral line emitted during the discharge can be used for measurements of plasma rotation. In addition, this calibration provides a check on the spectral dispersion needed to determine the ion temperature. The reference spectra for the calibration are Ne I lines created by neon capillary discharge lamps contained within specially designed, diffuse reflectors. The Ne I lines at 3520.4720 angstrom, 5274.0393 angstrom, 5280.0853 angstrom, 5298.1891 angstrom, and 5304.7580 angstrom are used in this work. The location of these lines on the linear detectors can be determined to an accuracy of 0.1 pixel, which corresponds to a plasma rotation accuracy of 1.2 km/s and 0.7 km/s for the central and edge rotation measurements, respectively. Use of oppositely directed views of the plasma at the same major radius have been used to verify that the nominal 5290.5 angstrom wavelength of the C VI (n = 8 → 7) multiplet is the correct wavelength for the line emitted owing to charge exchange excitation

  17. A vision-based self-calibration method for robotic visual inspection systems.

    Science.gov (United States)

    Yin, Shibin; Ren, Yongjie; Zhu, Jigui; Yang, Shourui; Ye, Shenghua

    2013-12-03

    A vision-based robot self-calibration method is proposed in this paper to evaluate the kinematic parameter errors of a robot using a visual sensor mounted on its end-effector. This approach could be performed in the industrial field without external, expensive apparatus or an elaborate setup. A robot Tool Center Point (TCP) is defined in the structural model of a line-structured laser sensor, and aligned to a reference point fixed in the robot workspace. A mathematical model is established to formulate the misalignment errors with kinematic parameter errors and TCP position errors. Based on the fixed point constraints, the kinematic parameter errors and TCP position errors are identified with an iterative algorithm. Compared to the conventional methods, this proposed method eliminates the need for a robot-based-frame and hand-to-eye calibrations, shortens the error propagation chain, and makes the calibration process more accurate and convenient. A validation experiment is performed on an ABB IRB2400 robot. An optimal configuration on the number and distribution of fixed points in the robot workspace is obtained based on the experimental results. Comparative experiments reveal that there is a significant improvement of the measuring accuracy of the robotic visual inspection system.

  18. A robust calibration technique for acoustic emission systems based on momentum transfer from a ball drop

    Science.gov (United States)

    McLaskey, Gregory C.; Lockner, David A.; Kilgore, Brian D.; Beeler, Nicholas M.

    2015-01-01

    We describe a technique to estimate the seismic moment of acoustic emissions and other extremely small seismic events. Unlike previous calibration techniques, it does not require modeling of the wave propagation, sensor response, or signal conditioning. Rather, this technique calibrates the recording system as a whole and uses a ball impact as a reference source or empirical Green’s function. To correctly apply this technique, we develop mathematical expressions that link the seismic moment $M_{0}$ of internal seismic sources (i.e., earthquakes and acoustic emissions) to the impulse, or change in momentum $\\Delta p $, of externally applied seismic sources (i.e., meteor impacts or, in this case, ball impact). We find that, at low frequencies, moment and impulse are linked by a constant, which we call the force‐moment‐rate scale factor $C_{F\\dot{M}} = M_{0}/\\Delta p$. This constant is equal to twice the speed of sound in the material from which the seismic sources were generated. Next, we demonstrate the calibration technique on two different experimental rock mechanics facilities. The first example is a saw‐cut cylindrical granite sample that is loaded in a triaxial apparatus at 40 MPa confining pressure. The second example is a 2 m long fault cut in a granite sample and deformed in a large biaxial apparatus at lower stress levels. Using the empirical calibration technique, we are able to determine absolute source parameters including the seismic moment, corner frequency, stress drop, and radiated energy of these magnitude −2.5 to −7 seismic events.

  19. The study of calibration and epipolar geometry for the stereo vision system built by fisheye lenses

    Science.gov (United States)

    Zhang, Baofeng; Lu, Chunfang; Röning, Juha; Feng, Weijia

    2015-01-01

    Fish-eye lens is a kind of short focal distance (f=6~16mm) camera. The field of view (FOV) of it is near or even exceeded 180×180 degrees. A lot of literatures show that the multiple view geometry system built by fish-eye lens will get larger stereo field than traditional stereo vision system which based on a pair of perspective projection images. Since a fish-eye camera usually has a wider-than-hemispherical FOV, the most of image processing approaches based on the pinhole camera model for the conventional stereo vision system are not satisfied to deal with the applications of this category of stereo vision which built by fish-eye lenses. This paper focuses on discussing the calibration and the epipolar rectification method for a novel machine vision system set up by four fish-eye lenses, which is called Special Stereo Vision System (SSVS). The characteristic of SSVS is that it can produce 3D coordinate information from the whole global observation space and acquiring no blind area 360º×360º panoramic image simultaneously just using single vision equipment with one time static shooting. Parameters calibration and epipolar rectification is the basic for SSVS to realize 3D reconstruction and panoramic image generation.

  20. Electron beam test of key elements of the laser-based calibration system for the muon $g$ $-$ $2$ experiment

    CERN Document Server

    Anastasi, A; Bedeschi, F; Bartolini, M; Cantatore, G; Cauz, D; Corradi, G; Dabagov, S; DI Sciascio, G; Di Stefano, R; Driutti, A; Escalante, O; Ferrari, C; Fienberg, A T; Fioretti, A; Gabbanini, C; Gioiosa, A; Hampai, D; Hertzog, D W; Iacovacci, M; Karuza, M; Kaspar, J; Liedl, A; Luisiani, A; Marignetti, F; Mastroianni, S; Moricciani, D; Pauletta, G; Piacentino, G M; Raha, N; Rossi, E; Santi, L; Venanzoni, G

    2016-01-01

    We report the test of many of the key elements of the laser-based calibration system for muon g - 2 experiment E989 at Fermilab. The test was performed at the Laboratori Nazionali di Frascati's Beam Test Facility using a 450 MeV electron beam impinging on a small subset of the final g - 2 lead-fluoride crystal calorimeter system. The calibration system was configured as planned for the E989 experiment and uses the same type of laser and most of the final optical elements. We show results regarding the calorimeter's response calibration, the maximum equivalent electron energy which can be provided by the laser and the stability of the calibration system components.

  1. Double-theodolite measurement system used in the image calibration of space photographic instrument

    Institute of Scientific and Technical Information of China (English)

    LI Yan; QIAO Yan-feng; SU Wan-xin; LIU Ze-xun

    2005-01-01

    The purpose of characterizing the image of space photographic instrument is to gain the space included angles from three coordinate axes in the three-dimensional coordinate of the image and the directionality of the three axes of coordinate in the frame of axes of the instrument. The two reference frames will keep in the same direction finally by adjusting according to space angles. This problem was solved by a new high-precision measurement system composed of a double-theodolite and a set of communication system. In the survey system, two TDA5005 total stations from Leica Company will be selected as the double-theodolite and the interdependence of both coordinate systems can be achieved by moving the stations only at one time. Therefore, this measurement system provides a highly efficient and high-precision surveying method to the image calibration of the space photographic instrument. According to the experiment, its measuring accuracy can reach arc-second level.

  2. Data Acquisition and Management in the Calibration Processes of the CMS Barrel Muon Alignment System

    CERN Document Server

    Székely, Géza; Bencze, Gy L; Béni, N; Imrek, J; Molnár, J; Novák, D; Raics, P; Szabó, Z

    2007-01-01

    In order to be able to match correctly the track elements produced by a muon in the Tracker and the Muon System of the CMS experiment [1] the mutual alignment precision between the Tracker and the Barrel Muon System must be no worse than 100-400 micrometers depending on the radial distance of the muon chambers from the Tracker. To fulfill this requirement an alignment system had to be designed. This system contains subsystems for determining the positions of the barrel and endcap chambers while a third one connects these two to the Tracker. Since the Barrel muon chambers are embedded into the magnet yoke of the experiment a nonconventional alignment method had to be developed. In this paper we restrict ourselves to the Barrel Alignment System and the calibration methods of its components.

  3. The construction and testing of the portable Hg(2+) ultrasonic calibrator for the control of mercury speciation systems.

    Science.gov (United States)

    Gorecki, Jerzy; Okonska, Anna

    2016-01-15

    During fuel combustion mercury, as Hg(0) and Hg(2+) forms, is emitted to the atmosphere. Effective reduction of mercury emission requires applying speciation systems for emission control and research. An important part of all mercury determination and speciation systems are the calibrators. Calibrators are responsible for the accuracy of mercury determination and, in consequence, the effective reduction of mercury emission. The aim of the work was to construct a portable HgCl2 calibrator. The purpose of the device was the control of mercury speciation systems for continuous measurements and study of HgCl2 sorption. As a result of previously conducted research, the portable Hg(2+) ultrasonic calibrator was designed, constructed and tested. The ultrasonic calibrator generates a stable stream of HgCl2 (RSD=2.8% for CHg=28µg/m(3)). The correlation between theoretical and reading concentration of HgCl2 was R(2)=0.9983. The average recovery of HgCl2 was 95%. The advantages of the ultrasonic Hg(2+) calibrator are: high accuracy and selectivity, low pressure of HgCl2 stream and very low cost of production. The calibrator was successfully tested, both in the laboratory and in the power plant, during a preliminary study on HgCl2 sorption on a fly ash filter. PMID:26592572

  4. On calibrating the sensor errors of a PDR-based indoor localization system.

    Science.gov (United States)

    Lan, Kun-Chan; Shih, Wen-Yuah

    2013-01-01

    Many studies utilize the signal strength of short-range radio systems (such as WiFi, ultrasound and infrared) to build a radio map for indoor localization, by deploying a large number of beacon nodes within a building. The drawback of such an infrastructure-based approach is that the deployment and calibration of the system are costly and labor-intensive. Some prior studies proposed the use of Pedestrian Dead Reckoning (PDR) for indoor localization, which does not require the deployment of beacon nodes. In a PDR system, a small number of sensors are put on the pedestrian. These sensors (such as a G-sensor and gyroscope) are used to estimate the distance and direction that a user travels. The effectiveness of a PDR system lies in its success in accurately estimating the user's moving distance and direction. In this work, we propose a novel waist-mounted based PDR that can measure the user's step lengths with a high accuracy. We utilize vertical acceleration of the body to calculate the user's change in height during walking. Based on the Pythagorean Theorem, we can then estimate each step length using this data. Furthermore, we design a map matching algorithm to calibrate the direction errors from the gyro using building floor plans. The results of our experiment show that we can achieve about 98.26% accuracy in estimating the user's walking distance, with an overall location error of about 0.48 m. PMID:23575036

  5. A calibration system of O2 consumption and CO2 production for premature infants

    Science.gov (United States)

    Lin, Shih-Ching; Luo, Ching-Hsing; Yeh, Tsu-Fuh

    2001-03-01

    An apparatus to calibrate the system of measuring O2 consumption and CO2 production has been developed for premature infants. This system is based on the alcohol combustion principal. The alcohol combustion is used to test the indirect calorimetric system due to its simplicity and reliability. In the previous studies, the O2 consumption rate of alcoholic combustion is too large to simulate the breath of premature infants. A new design is proposed to burn alcohol continuously at a rate as low as 0.004 ml min-1, equivalent to an O2 consumption rate of only 3.9 ml min-1, a level in the breath range of preterms of about 660 g based on the measurement 5.9 ml kg-1 min-1. The alcohol combusts with various steady-state rates to imitate the breath of premature infants, and it is useful for a canopy open-circuit system. The calibration tool proposed here would be helpful in the clinical study of energy expenditure for preterms.

  6. Cinematica: a system for calibrated, Macintosh-driven displays from within Mathematica.

    Science.gov (United States)

    Solomon, J A; Watson, A B

    1996-01-01

    Cinematica is a minimal system for producing calibrated grayscale movies on an Apple Macintosh computer from within the Mathematica programming environment. It makes use of the ISR Video Attenuator and the Video Toolbox software library developed by Denis Pelli. By design, Cinematica provides a very low-level interface to the display routine. Display instructions take the form of a list of pairs (image index, colormap index). The philosophy is that programming is much easier in Mathematica than in C, so we reserve the complexity for Mathematica. A few simple examples are provided.

  7. The calibration system of the new g-2 experiment at Fermilab

    Science.gov (United States)

    Anastasi, A.; Babusci, D.; Cantatore, G.; Cauz, D.; Corradi, G.; Dabagov, S.; Di Meo, P.; Di Sciascio, G.; Di Stefano, R.; Ferrari, C.; Fienberg, A. T.; Fioretti, A.; Gabbanini, C.; Hampai, D.; Hertzog, D. W.; Iacovacci, M.; Karuza, M.; Kaspar, J.; Marignetti, F.; Mastroianni, S.; Moricciani, D.; Pauletta, G.; Santi, L.; Venanzoni, G.

    2016-07-01

    The muon anomaly (g - 2) μ / 2 has been measured to 0.54 parts per million by E821 experiment at Brookhaven National Laboratory, and at present there is a 3-4 standard-deviation difference between the Standard Model prediction and the experimental value. A new muon g-2 experiment, E989, is being prepared at Fermilab that will improve the experimental error by a factor of four to clarify this difference. A central component to reach this fourfold improvement in accuracy is the high-precision laser calibration system which should monitor the gain fluctuations of the calorimeter photodetectors at 0.04% accuracy.

  8. Calculations to support JET neutron yield calibration: Modelling of the JET remote handling system

    Energy Technology Data Exchange (ETDEWEB)

    Snoj, Luka, E-mail: luka.snoj@ijs.si [JET-EFDA, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); EURATOM-MHEST Association, Reactor Physics Division, Jožef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Lengar, Igor; Čufar, Aljaž [JET-EFDA, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); EURATOM-MHEST Association, Reactor Physics Division, Jožef Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana (Slovenia); Syme, Brian; Popovichev, Sergey [JET-EFDA, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); EURATOM-CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, OXON (United Kingdom); Conroy, Sean [JET-EFDA, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); EURATOM-VR Association, Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Meredith, Lewis [JET-EFDA, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); EURATOM-CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, OXON (United Kingdom)

    2013-08-15

    Highlights: ► We model JET remote handling system in MCNP. ► We examine the effect of JET remote handling system on neutron monitor response. ► The integral effect of JET RH system on neutron monitors is less than 5%. -- Abstract: After the coated CFC wall to ITER-Like Wall (Beryllium/Tungsten/Carbon) transition in 2010–2011, confirmation of the neutron yield calibration will be ensured by direct measurements using a calibrated {sup 252}Cf neutron source deployed by the in-vessel remote handling boom and Mascot manipulator inside the JET vacuum vessel. Neutronic calculations are required to calculate the effects of the JET remote handling (RH) system on the neutron monitors. We developed a simplified geometrical computational model of the JET remote handling system in MCNP. In parallel we developed a script that translates the RH movement data to transformations of individual geometrical parts of the RH model in MCNP. After that a benchmarking of the model was performed to verify and validate the accordance of the target positions of source and RH system with the ones from our model. In the last phase we placed the JET RH system in the simplified MCNP model of the JET tokamak and studied its effect on neutron monitor response for some example source positions and boom configurations. As the correction factors due to presence of the JET RH system can potentially be significant in cases when the boom is blocking a port close to the detector under investigation, we have chosen boom configurations so that this is avoided in the vast majority of the source locations. Examples are given.

  9. Calibration of line structured light vision system based on camera's projective center

    Institute of Scientific and Technical Information of China (English)

    ZHU Ji-gui; LI Yan-jun; YE Sheng-hua

    2005-01-01

    Based on the characteristics of line structured light sensor, a speedy method for the calibration was established. With the coplanar reference target, the spacial pose between camera and optical plane can be calibrated by using of the camera's projective center and the light's information in the camera's image surface. Without striction to the movement of the coplanar reference target and assistant adjustment equipment, this calibration method can be implemented. This method has been used and decreased the cost of calibration equipment, simplified the calibration procedure, improved calibration efficiency. Using experiment, the sensor can attain relative accuracy about 0.5%, which indicates the rationality and effectivity of this method.

  10. A preliminary investigation of the dynamic force-calibration of a magnetic suspension and balance system

    Science.gov (United States)

    Goodyer, M. J.

    1985-01-01

    The aerodynamic forces and moments acting upon a magnetically suspended wind tunnel model are derived from calibrations of suspension electro magnet currents against known forces. As an alternative to the conventional calibration method of applying steady forces to the model, early experiences with dynamic calibration are outlined, that is a calibration obtained by oscillating a model in suspension and deriving a force/current relationship from its inertia force and the unsteady components of currents. Advantages of dynamic calibration are speed and simplicity. The two methods of calibration applied to one force component show good agreement.

  11. Calibration of Dissolved Noble Gas Mass Spectrometric Measurements by an Air-Water Equilibration System

    Science.gov (United States)

    Hillegonds, Darren; Matsumoto, Takuya; Jaklitsch, Manfred; Han, Liang-Feng; Klaus, Philipp; Wassenaar, Leonard; Aggarwal, Pradeep

    2013-04-01

    Precise measurements by mass spectrometry of dissolved noble gases (He, Ar, Ne, Kr, Xe) in water samples require careful calibration against laboratory standards with known concentrations. Currently, air pipettes are used for day-to-day calibrations, making estimation of overall analytical uncertainties for dissolved noble gas measurements in water difficult. Air equilibrated water (AEW) is often used as a matrix-equivalent laboratory standard for dissolved gases in groundwater, because of the well-known and constant fractions of noble gases in the atmosphere. AEW standards, however, are only useful if the temperature and pressure of the gas-water equilibrium can be controlled and measured precisely (i.e., to better than 0.5%); contamination and partial sample degassing must also be prevented during sampling. Here we present the details of a new custom air-water equilibration system which consists of an insulated 600 liter tank filled with deionized water, held isothermally at a precise target temperature (water in the tank are monitored continually, as are atmospheric pressure and air temperature in the laboratory. Different noble gas concentration standards can be reliably produced by accurately controlling the water temperature of the equilibration system. Equilibration characteristics and reproducibility of this system for production of copper tubes containing known amounts of noble gases will be presented.

  12. Mathematical Model and Calibration Procedure of a PSD Sensor Used in Local Positioning Systems

    Science.gov (United States)

    Rodríguez-Navarro, David; Lázaro-Galilea, José Luis; Bravo-Muñoz, Ignacio; Gardel-Vicente, Alfredo; Domingo-Perez, Francisco; Tsirigotis, Georgios

    2016-01-01

    Here, we propose a mathematical model and a calibration procedure for a PSD (position sensitive device) sensor equipped with an optical system, to enable accurate measurement of the angle of arrival of one or more beams of light emitted by infrared (IR) transmitters located at distances of between 4 and 6 m. To achieve this objective, it was necessary to characterize the intrinsic parameters that model the system and obtain their values. This first approach was based on a pin-hole model, to which system nonlinearities were added, and this was used to model the points obtained with the nA currents provided by the PSD. In addition, we analyzed the main sources of error, including PSD sensor signal noise, gain factor imbalances and PSD sensor distortion. The results indicated that the proposed model and method provided satisfactory calibration and yielded precise parameter values, enabling accurate measurement of the angle of arrival with a low degree of error, as evidenced by the experimental results. PMID:27649189

  13. The Research of Through-casing Resistivity Logging Logging Calibration System Leakage Current Measurement Method

    Directory of Open Access Journals (Sweden)

    ZHANG Jiatian

    2013-07-01

    Full Text Available This paper introduces the logging principle of through-casing resistivity logging technology, finds a phenomenon that the leakage current measurements are susceptible to sufferring interferences. The through-casing resistivity logging technology in Russia and that of Schlumberger are studied, and the system of through-casing resistivity logging is established to improve the accuracy of calibrating, testing and measuring of the instrument. In this paper, distribution parameters of the form is replaced by the lumped parameter, and precision resistor array simulation in formation leakage current and scale pool simulation in different resistivity of formation are conducted, which make the dynamic range of the simulation in formation resistivity of the medium increase to 1- 300 Ω·m and meet the requirement of through-casing resistivity logging technology measurement range, 1 Ω·m ~ 100 Ω·m. Since the measuring signals of calibration acquisition and processing systems are extremely weak and calculation signals need to tell the nV (nanovolts level, the high accurate data acquisition system of 24 digits is applied.

  14. On the Free Vibration Modeling of Spindle Systems: A Calibrated Dynamic Stiffness Matrix

    Directory of Open Access Journals (Sweden)

    Omar Gaber

    2014-01-01

    Full Text Available The effect of bearings on the vibrational behavior of machine tool spindles is investigated. This is done through the development of a calibrated dynamic stiffness matrix (CDSM method, where the bearings flexibility is represented by massless linear spring elements with tuneable stiffness. A dedicated MATLAB code is written to develop and to assemble the element stiffness matrices for the system’s multiple components and to apply the boundary conditions. The developed method is applied to an illustrative example of spindle system. When the spindle bearings are modeled as simply supported boundary conditions, the DSM model results in a fundamental frequency much higher than the system’s nominal value. The simply supported boundary conditions are then replaced by linear spring elements, and the spring constants are adjusted such that the resulting calibrated CDSM model leads to the nominal fundamental frequency of the spindle system. The spindle frequency results are also validated against the experimental data. The proposed method can be effectively applied to predict the vibration characteristics of spindle systems supported by bearings.

  15. Mathematical Model and Calibration Procedure of a PSD Sensor Used in Local Positioning Systems.

    Science.gov (United States)

    Rodríguez-Navarro, David; Lázaro-Galilea, José Luis; Bravo-Muñoz, Ignacio; Gardel-Vicente, Alfredo; Domingo-Perez, Francisco; Tsirigotis, Georgios

    2016-01-01

    Here, we propose a mathematical model and a calibration procedure for a PSD (position sensitive device) sensor equipped with an optical system, to enable accurate measurement of the angle of arrival of one or more beams of light emitted by infrared (IR) transmitters located at distances of between 4 and 6 m. To achieve this objective, it was necessary to characterize the intrinsic parameters that model the system and obtain their values. This first approach was based on a pin-hole model, to which system nonlinearities were added, and this was used to model the points obtained with the nA currents provided by the PSD. In addition, we analyzed the main sources of error, including PSD sensor signal noise, gain factor imbalances and PSD sensor distortion. The results indicated that the proposed model and method provided satisfactory calibration and yielded precise parameter values, enabling accurate measurement of the angle of arrival with a low degree of error, as evidenced by the experimental results.

  16. Facile fabrication of uniform size-controlled microparticles and potentiality for tandem drug delivery system of micro/nanoparticles.

    Science.gov (United States)

    Iwanaga, Shintaroh; Saito, Noriaki; Sanae, Hidetoshi; Nakamura, Makoto

    2013-09-01

    This article describes a rapid and facile method for manufacturing various size-controlled gel particles with utilizing inkjet printing technology. Generally, the size of droplets could be controlled by changing nozzle heads of inkjet printer, from which ink solution is ejected. However, this method uses drying process before gelling microparticles, and with that, the size of microparticles was easily controlled by only altering the concentration of ejected solution. When sodium alginate solution with various concentrations was ejected from inkjet printer, we found that the concentration of alginate solution vs. the volume of dried alginate particle showed an almost linear relationship in the concentration range from 0.1 to 3.0%. After dried alginate particles were soaked into calcium chloride solution, the size of microgel beads were obtained almost without increasing their size. The microparticles including various sizes of nanoparticles were easily manufactured by ejecting nanoparticle-dispersed alginate solution. The release of 25-nm sized nanoparticles from alginate microgel beads was finished in a relatively-rapid manner, whereas 100-nm sized nanoparticles were partially released from those ones. Moreover, most of 250-nm sized nanoparticles were not released from alginate microgel beads even after 24-h soaking. This particle fabricating method would enable the tandem drug delivery system with a combination of the release from nano and microparticles, and be expected for the biological and tissue engineering application.

  17. The research on calibration methods of dual-CCD laser three-dimensional human face scanning system

    Science.gov (United States)

    Wang, Jinjiang; Chang, Tianyu; Ge, Baozhen; Tian, Qingguo; Yang, Fengting; Shi, Shendong

    2013-09-01

    In this paper, on the basis of considering the performance advantages of two-step method, we combines the stereo matching of binocular stereo vision with active laser scanning to calibrate the system. Above all, we select a reference camera coordinate system as the world coordinate system and unity the coordinates of two CCD cameras. And then obtain the new perspective projection matrix (PPM) of each camera after the epipolar rectification. By those, the corresponding epipolar equation of two cameras can be defined. So by utilizing the trigonometric parallax method, we can measure the space point position after distortion correction and achieve stereo matching calibration between two image points. Experiments verify that this method can improve accuracy and system stability is guaranteed. The stereo matching calibration has a simple process with low-cost, and simplifies regular maintenance work. It can acquire 3D coordinates only by planar checkerboard calibration without the need of designing specific standard target or using electronic theodolite. It is found that during the experiment two-step calibration error and lens distortion lead to the stratification of point cloud data. The proposed calibration method which combining active line laser scanning and binocular stereo vision has the both advantages of them. It has more flexible applicability. Theory analysis and experiment shows the method is reasonable.

  18. On the linearity of the MINOS light-injection calibration system

    International Nuclear Information System (INIS)

    The MINOS light-injection calibration system has been fully documented in a previous article (Nucl. Instr. and Meth. A 492 (2002) 353). Upon commissioning in the MINOS detectors, the system was found to give a non-linear response to variations in the intensity of injected light. The source of this non-linearity has been traced to a small change in the spectrum of the injected light as a function of the current applied to the original blue LEDs, in combination with a rapidly varying spectral response function of the wavelength-shifting fibre used in the detector. Both aspects of the problem have been addressed successfully by use of LEDs with different spectral characteristics, and the system now has a linear response

  19. Calibration and Validation of Measurement System:Wave Dragon, Nissum Bredning

    OpenAIRE

    Kofoed, Jens Peter; Riemann, Sven; Knapp, Wilfried

    2004-01-01

    The report deals with the calibration of the measuring equipment on board the Wave Dragon, Nissum Bredning prototype. The report deals with the calibration of the measuring equipment on board the Wave Dragon, Nissum Bredning prototype.

  20. Upgrade of the Laser Calibration System of the Atlas Hadron Calorimeter

    CERN Document Server

    Gris, Philippe Luc Yves; The ATLAS collaboration

    2015-01-01

    The new laser calibration scheme of the ATLAS Tile calorimeter is presented with a focus on improvements of three critical aspects (optics, calibration, electronics). The resulting performance in terms of stability is also indicated.

  1. The Monitoring and Calibration Web Systems for the ATLAS Tile Calorimeter Data Quality Analysis

    CERN Document Server

    Sivolella, A; Ferreira, F

    2012-01-01

    The Tile Calorimeter (TileCal) is one of the ATLAS sub-detectors. The read-out is performed by about 10,000 PhotoMultiplier Tubes (PMTs). The signal of each PMT is digitized by an electronic channel. The Monitoring and Calibration Web System (MCWS) supports the data quality analysis of the electronic channels. This application was developed to assess the detector status and verify its performance. It can provide to the user the list of TileCal known problematic channels, that is stored in the ATLAS condition database (COOL DB). The bad channels list guides the data quality validator in identifying new problematic channels and is used in data reconstruction and the system allows to update the channels list directly in the COOL database. MCWS can generate summary results, such as eta-phi plots and comparative tables of the masked channels percentage. Regularly, during the LHC (Large Hadron Collider) shutdown a maintenance of the detector equipments is performed. When a channel is repaired, its calibration const...

  2. Diamagnetic Levitation Cantilever System for the Calibration of Normal Force Atomic Force Microscopy Measurements

    Science.gov (United States)

    Torres, Jahn; Yi, Jin-Woo; Murphy, Colin; Kim, Kyung-Suk

    2011-03-01

    In this presentation we report a novel technique for normal force calibration for Atomic Force Microcopy (AFM) adhesion measurements known as the diamagnetic normal force calibration (D-NFC) system. The levitation produced by the repulsion between a diamagnetic graphite sheet and a set of rare-earth magnets is used in order to produce an oscillation due to an unstable mechanical moment produced by a silicon cantilever supported on the graphite. The measurement of the natural frequency of this oscillation allows for the calculation of the stiffness of the system to three-digit accuracy. The D-NFC response was proven to have a high sensitivity for the structure of water molecules collected on its surface. This in turns allows for the study of the effects of coatings on the structure of surface water. This work was supported by the Coatings/Biofouling Program and the Maritime Sensing Program of the Office of Naval Research as well as the ILIR Program of the Naval Undersea Warfare Center DIVNPT.

  3. Automatic Calibration Method of Voxel Size for Cone-beam 3D-CT Scanning System

    CERN Document Server

    Yang, Min; Liu, Yipeng; Men, Fanyong; Li, Xingdong; Liu, Wenli; Wei, Dongbo

    2013-01-01

    For cone-beam three-dimensional computed tomography (3D-CT) scanning system, voxel size is an important indicator to guarantee the accuracy of data analysis and feature measurement based on 3D-CT images. Meanwhile, the voxel size changes with the movement of the rotary table along X-ray direction. In order to realize the automatic calibration of the voxel size, a new easily-implemented method is proposed. According to this method, several projections of a spherical phantom are captured at different imaging positions and the corresponding voxel size values are calculated by non-linear least square fitting. Through these interpolation values, a linear equation is obtained, which reflects the relationship between the rotary table displacement distance from its nominal zero position and the voxel size. Finally, the linear equation is imported into the calibration module of the 3D-CT scanning system, and when the rotary table is moving along X-ray direction, the accurate value of the voxel size is dynamically expo...

  4. Calibration System with Optical Fibers for Calorimeters at Future Linear Collider Experiments

    CERN Document Server

    ,

    2012-01-01

    We report on several versions of the calibration and monitoring system dedicated to scintillator tile calorimeters built within the CALICE collaboration and intended for future linear collider experiments. Whereas the first, a 1 m3 analogue hadron calorimeter prototype, was already built and tested in beam, second-technological prototype-is currently being developed. Both prototypes are based on scintillating tiles that are individually read out by new photodetectors, silicon photomultipliers (SiPMs). Since the SiPM response shows a strong dependence on the temperature and bias voltage and the SiPM saturates due to the limited number of pixels, it needs to be monitored. The monitoring system has to have sufficient flexibility to perform several different tasks. The self-calibration property of the SiPMs can be used for the gain monitoring using a low intensity of the LED light. A routine monitoring of all SiPMs during test beam operations is achieved with a fixed-intensity light pulse. The full SiPM response ...

  5. Automatic Calibration of Frequency Compensation System in Computer-Controlled Patch-Clamp Amplifier

    Directory of Open Access Journals (Sweden)

    Jun Xion

    2007-01-01

    Full Text Available Computer-controlled patch-clamp amplifier is a digitally controlled analog device used to record the cellular ion channel currents in electrophysiology research. The inherent bandwidth and performance of the headstage is limited by the stray capacitance and distributed capacitance across the feedback resistors. In order to effectively improve the performance of the headstage, the paper advanced a simplified automatic calibration method of frequency compensation system in resistor-feedback patch-clamp amplifier. The dynamic model of headstage was approximate as a two poles and one zero system in the transfer function by experience and test results, so the dynamic characteristics of the headstage were obtained employing least squares parameter estimation algorithm. Further more, the compensation parameter of high frequency booster can be estimated by the time constant of main pole of headstage. And automatic adjustment of the parameters in transient response correction stage was performed as a least squares fitting problem. The software routine running on the host computer conducted all operations of frequency compensation. Experimental results demonstrate that the simplified automatic calibration method can substantially extend the bandwidth and minimize step response error of headstage.

  6. Characterisation Of Corner Reflectors For The Australian Geophysical Observing System To Support SAR Calibration

    Science.gov (United States)

    Thankappan, Medhavy; Garthwaite, Matthew C.; Williams, Mark L.; Hislop, Andrew; Nancarrow, Shane; Dawson, John

    2013-12-01

    The Australian Government has invested $23 million in building the Australian Geophysical Observing System (AGOS). AGOS will enable highly accurate spatial and temporal estimation of large-scale ground deformation. The key geospatial components of AGOS include Global Navigation Satellite System (GNSS) instrumentation, high precision GPS monuments, corner reflectors and a Synthetic Aperture Radar (SAR) data repository. The corner reflector (CR) array that forms a key piece of AGOS infrastructure will enable the precise measurement of crustal deformation using Interferometric SAR(InSAR) techniques. The CR array will also provide a reliable means to perform independent and ongoing radiometric, geometric and impulse response measurements for the calibration of a number of satellite-borne SAR instruments. A combination of plate sizes and materials have been used in the design and construction of 18 different CR prototypes. Radar Cross Section (RCS) measurements for all CR prototypes was undertaken at the Defence Science and Technology Organisation (DSTO) outdoor radar ground range facility to compare theoretical versus actual values for a range of azimuth and elevation combinations and characterise the design performance. The prototypes will be deployed at a field site for testing over a 3-month period. Data captures over the test site will be planned, with satellite-borne X and C-band SAR instruments to assess the response performance of the CR prototypes for calibration activities. The design, construction, RCS measurements, deployment and field performance of the CR is covered in this paper.

  7. Analysis of the Laser Calibration System for the CMS HCAL at CERN's Large Hadron Collider

    Science.gov (United States)

    Lebolo, Luis

    2005-11-01

    The European Organization for Nuclear Physics' (CERN) Large Hadron Collider uses the Compact Muon Solenoid (CMS) detector to measure collision products from proton-proton interactions. CMS uses a hadron calorimeter (HCAL) to measure the energy and position of quarks and gluons by reconstructing their hadronic decay products. An essential component of the detector is the calibration system, which was evaluated in terms of its misalignment, linearity, and resolution. In order to analyze the data, the authors created scripts in ROOT 5.02/00 and C++. The authors also used Mathematica 5.1 to perform complex mathematics and AutoCAD 2006 to produce optical ray traces. The misalignment of the optical components was found to be satisfactory; the Hybrid Photodiodes (HPDs) were confirmed to be linear; the constant, noise and stochastic contributions to its resolution were analyzed; and the quantum efficiency of most HPDs was determined to be approximately 40%. With a better understanding of the laser calibration system, one can further understand and improve the HCAL.

  8. Development and application of a dosimetric methodology of therapeutic X radiation beams using a tandem system; Desenvolvimento e aplicacao de metodologia dosimetrica de feixes terapeuticos de raios X com sistema tandem

    Energy Technology Data Exchange (ETDEWEB)

    Sartoris, Carla Eri

    2001-07-01

    In radiotherapy the use of orthovoltage X radiation beams is still recommended; to obtain satisfactory results, a periodic control is necessary to check the performance of the ionization chambers and the radiation beams characteristics. This control is performed by using standard dosimetric procedures, as for example the determination of half-value layers and the absorbed dose rates. A Tandem system was established in this work using a pair of ionization chambers (a thimble type and a superficial type) used for measures in a medical institution, in substitution to the routine conventional procedure of determination of half-value layers using absorbers. The results obtained show the application of this method in dosimetric procedures of orthovoltage beams (radiotherapy) as a complement for a quality control program. (author)

  9. The injector of the Utrecht en tandem

    OpenAIRE

    Zwol, N.A. van; van der Borg, K.; de Haas, A.P.; Hoogenboom, A.M.; Strasters, B.A.; Vermeer, A.

    1984-01-01

    An injector has been built to obtain improved beam transmission through the EN tandem. The injector has been provided with a 90° analysing magnet, m/Δm = 300, and 130 kV preacceleration. Beam optics calculations have been made for the injector and tandem. The injector has been equipped with a fiber optics control and data acquisition system.

  10. Preliminary results of the first static calibration of the RSRA helicopter active-isolator rotor balance system

    Science.gov (United States)

    Acree, C. W., Jr.

    1983-01-01

    The helicopter version of the Rotor Systems Research Aircraft (RSRA) is designed to make simultaneous measurements of all rotor forces and moments in flight analogous to a wind tunnel balance. Loads are measured by a combination of load cells, strain gages, and hydropneumatic active isolators which use pressure gages to measure loads. Complete evaluation of system performance required calibration of the rotor force and moment measuring system when installed in the aircraft. Measurement system responses to rotor loads obtained during the first static calibration of the RSRA helicopter are plotted and discussed. Plots of the raw transducer data are included.

  11. Research on six-degree-of-freedom calibration system for wind tunnel balances with a collimated laser beam

    Science.gov (United States)

    Fan, Zhigang; He, Jin; Zuo, Baojun; Li, Runshun; Jia, Yuansheng; Gui, Bing; Qiu, Junwen; Dong, Milin

    2003-02-01

    A newly-developed six-degree-of-freedom calibration system for the wind tunnel balances is introduced. The frame of the system, the functions and the operating principle of different parts are presented in detail. The system is composed of four parts: the automatically loading subsystem, the automatically resetting subsystem, the data-acquisition subsystem and the measurement subsystem. The results of some cell experiments proved that the system can meet the needs of the present calibration task of the balance. Through further improvement, the system can be also used to calibrate other devices with multi degree-of-freedom and measure the minute shifts, such as the guide rail of machine tool and the assembling of large parts and so on.

  12. Research on six-degree-of-freedom calibration system for wind tunnel balances with a collimated laser beam

    Institute of Scientific and Technical Information of China (English)

    Zhigang Fan(范志刚); Jin He(何瑾); Baojun Zuo(左保军); Runshun Li(李润顺); Yuansheng Jia(贾元胜); Bing Gui(桂兵); Junwen Qiu(邱俊文); Milin Dong(董密林)

    2003-01-01

    A newly-developed six-degree-of-freedom calibration system for the wind tunnel balances is introduced.The frame of the system, the functions and the operating principle of different parts are presented indetail. The system is composed of four parts: the automatically loading subsystem, the automaticallyresetting subsystem, the data-acquisition subsystem and the measurement subsystem. The results ofsome cell experiments proved that the system can meet the needs of the present calibration task of thebalance. Through further improvement, the system can be also used to calibrate other devices withmulti degree-of-freedom and measure the minute shifts, such as the guide rail of machine tool and theassembling of large parts and so on.

  13. An improved robust hand-eye calibration for endoscopy navigation system

    Science.gov (United States)

    He, Wei; Kang, Kumsok; Li, Yanfang; Shi, Weili; Miao, Yu; He, Fei; Yan, Fei; Yang, Huamin; Zhang, Huimao; Mori, Kensaku; Jiang, Zhengang

    2016-03-01

    Endoscopy is widely used in clinical application, and surgical navigation system is an extremely important way to enhance the safety of endoscopy. The key to improve the accuracy of the navigation system is to solve the positional relationship between camera and tracking marker precisely. The problem can be solved by the hand-eye calibration method based on dual quaternions. However, because of the tracking error and the limited motion of the endoscope, the sample motions may contain some incomplete motion samples. Those motions will cause the algorithm unstable and inaccurate. An advanced selection rule for sample motions is proposed in this paper to improve the stability and accuracy of the methods based on dual quaternion. By setting the motion filter to filter out the incomplete motion samples, finally, high precision and robust result is achieved. The experimental results show that the accuracy and stability of camera registration have been effectively improved by selecting sample motion data automatically.

  14. The Monitoring and Calibration Web Systems for the ATLAS Tile Calorimeter Data Quality Analysis

    CERN Document Server

    Sivolella, A; The ATLAS collaboration; Ferreira, F

    2012-01-01

    The Tile Calorimeter (TileCal), one of the ATLAS detectors, has four partitions, where each one contains 64 modules and each module has up to 48 PhotoMulTipliers (PMTs), totalizing more than 10,000 electronic channels. The Monitoring and Calibration Web System (MCWS) supports data quality analyses at channels level. This application was developed to assess the detector status and verify its performance, presenting the problematic known channels list from the official database that stores the detector conditions data (COOL). The bad channels list guides the data quality validator during analyses in order to identify new problematic channels. Through the system, it is also possible to update the channels list directly in the COOL database. MCWS generates results, as eta-phi plots and comparative tables with masked channels percentage, which concerns TileCal status, and it is accessible by all ATLAS collaboration. Annually, there is an intervention on LHC (Large Hadronic Collider) when the detector equipments (P...

  15. Photoelectrochemical cell/dye-sensitized solar cell tandem water splitting systems with transparent and vertically aligned quantum dot sensitized TiO2 nanorod arrays

    Science.gov (United States)

    Shin, Kahee; Yoo, Ji-Beom; Park, Jong Hyeok

    2013-03-01

    The present work reports fabrication of vertically aligned CdS sensitized TiO2 nanorod arrays grown on transparent conducting oxide substrate with high transparency as a photoanode in photoelectrochemical cell for water splitting. To realize an unassisted water splitting system, the photoanode and dye-sensitized solar cell tandem structures are tried and their electrochemical behaviors are also investigated. The hydrothermally grown TiO2 nanorod arrays followed by CdS nanoparticle decoration can improve the light absorption of long wavelength light resulting in increased photocurrent density. Two different techniques (electrodeposition and spray pyrolysis deposition) of CdS nanoparticle sensitization are carried out and their water splitting behaviors in the tandem cell are compared.

  16. On Calibrating the Sensor Errors of a PDR-Based Indoor Localization System

    Directory of Open Access Journals (Sweden)

    Wen-Yuah Shih

    2013-04-01

    Full Text Available Many studies utilize the signal strength of short-range radio systems (such as WiFi, ultrasound and infrared to build a radio map for indoor localization, by deploying a large number of beacon nodes within a building. The drawback of such an infrastructure-based approach is that the deployment and calibration of the system are costly and labor-intensive. Some prior studies proposed the use of Pedestrian Dead Reckoning (PDR for indoor localization, which does not require the deployment of beacon nodes. In a PDR system, a small number of sensors are put on the pedestrian. These sensors (such as a G-sensor and gyroscope are used to estimate the distance and direction that a user travels. The effectiveness of a PDR system lies in its success in accurately estimating the user’s moving distance and direction. In this work, we propose a novel waist-mounted based PDR that can measure the user’s step lengths with a high accuracy. We utilize vertical acceleration of the body to calculate the user’s change in height during walking. Based on the Pythagorean Theorem, we can then estimate each step length using this data. Furthermore, we design a map matching algorithm to calibrate the direction errors from the gyro using building floor plans. The results of our experiment show that we can achieve about 98.26% accuracy in estimating the user’s walking distance, with an overall location error of about 0.48 m.

  17. The geometric calibration of cone-beam imaging and delivery systems in radiation therapy

    CERN Document Server

    Matsinos, E; Kaissl, Wolfgang; Matsinos, Evangelos

    2006-01-01

    We propose a method to achieve the geometric calibration of cone-beam imaging and delivery systems in radiation therapy; our approach applies to devices where an X-ray source and a flat-panel detector, facing each other, move in circular orbits around the irradiated object. In order to extract the parameters of the geometry from the data, we use a light needle phantom which is easy to manufacture. A model with ten free parameters (spatial lengths and distortion angles) has been put forth to describe the geometry and the mechanical imperfections of the units being calibrated; a few additional parameters are introduced to account for residual effects (small effects which lie beyond our model). The values of the model parameters are determined from one complete scan of the needle phantom via a robust optimisation scheme. The application of this method to two sets of five counterclockwise (ccw) and five clockwise (cw) scans yielded consistent and reproducible results. A number of differences have been observed be...

  18. The Pointing System of the Herschel Space Observatory. Description, Calibration, Performance and Improvements

    CERN Document Server

    Sánchez-Portal, Miguel; Altieri, Bruno; Aussel, Hervé; Feuchtgruber, Helmut; Klaas, Ulrich; Linz, Hendrik; Lutz, Dieter; Merín, Bruno; Müller, Thomas; Nielbock, Markus; Oort, Marc; Pilbratt, Göran; Schmidt, Micha; Stephenson, Craig; Tuttlebee, Mark

    2014-01-01

    We present the activities carried out to calibrate and characterise the performance of the elements of attitude control and measurement on board the Herschel spacecraft. The main calibration parameters and the evolution of the indicators of the pointing performance are described, from the initial values derived from the observations carried out in the performance verification phase to those attained in the last year and half of mission, an absolute pointing error around or even below 1 arcsec, a spatial relative pointing error of some 1 arcsec and a pointing stability below 0.2 arsec. The actions carried out at the ground segment to improve the spacecraft pointing measurements are outlined. On-going and future developments towards a final refinement of the Herschel astrometry are also summarised. A brief description of the different components of the attitude control and measurement system (both in the space and in the ground segments) is also given for reference. We stress the importance of the cooperation b...

  19. Multispectral calibration to enhance the metrology performance of C-mount camera systems

    Science.gov (United States)

    Robson, S.; MacDonald, L.; Kyle, S. A.; Shortis, M. R.

    2014-06-01

    Low cost monochrome camera systems based on CMOS sensors and C-mount lenses have been successfully applied to a wide variety of metrology tasks. For high accuracy work such cameras are typically equipped with ring lights to image retro-reflective targets as high contrast image features. Whilst algorithms for target image measurement and lens modelling are highly advanced, including separate RGB channel lens distortion correction, target image circularity compensation and a wide variety of detection and centroiding approaches, less effort has been directed towards optimising physical target image quality by considering optical performance in narrow wavelength bands. This paper describes an initial investigation to assess the effect of wavelength on camera calibration parameters for two different camera bodies and the same `C-mount' wide angle lens. Results demonstrate the expected strong influence on principal distance, radial and tangential distortion, and also highlight possible trends in principal point, orthogonality and affinity parameters which are close to the parameter estimation noise level from the strong convergent self-calibrating image networks.

  20. Cross-Calibration of Earth Observing System Terra Satellite Sensors MODIS and ASTER

    Science.gov (United States)

    McCorkel, J.

    2014-01-01

    The Advanced Spaceborne Thermal Emissive and Reflection Radiometer (ASTER) and Moderate Resolution Imaging Spectrometer (MODIS) are two of the five sensors onboard the Earth Observing System's Terra satellite. These sensors share many similar spectral channels while having much different spatial and operational parameters. ASTER is a tasked sensor and sometimes referred to a zoom camera of the MODIS that collects a full-earth image every one to two days. It is important that these sensors have a consistent characterization and calibration for continued development and use of their data products. This work uses a variety of test sites to retrieve and validate intercalibration results. The refined calibration of Collection 6 of the Terra MODIS data set is leveraged to provide the up-to-date reference for trending and validation of ASTER. Special attention is given to spatially matching radiance measurements using prelaunch spatial response characterization of MODIS. Despite differences in spectral band properties and spatial scales, ASTER-MODIS is an ideal case for intercomparison since the sensors have nearly identical views and acquisitions times and therefore can be used as a baseline of intercalibration performance of other satellite sensor pairs.

  1. An Accurate Calibration Method Based on Velocity in a Rotational Inertial Navigation System.

    Science.gov (United States)

    Zhang, Qian; Wang, Lei; Liu, Zengjun; Feng, Peide

    2015-01-01

    Rotation modulation is an effective method to enhance the accuracy of an inertial navigation system (INS) by modulating the gyroscope drifts and accelerometer bias errors into periodically varying components. The typical RINS drives the inertial measurement unit (IMU) rotation along the vertical axis and the horizontal sensors' errors are modulated, however, the azimuth angle error is closely related to vertical gyro drift, and the vertical gyro drift also should be modulated effectively. In this paper, a new rotation strategy in a dual-axis rotational INS (RINS) is proposed and the drifts of three gyros could be modulated, respectively. Experimental results from a real dual-axis RINS demonstrate that the maximum azimuth angle error is decreased from 0.04° to less than 0.01° during 1 h. Most importantly, the changing of rotation strategy leads to some additional errors in the velocity which is unacceptable in a high-precision INS. Then the paper studies the basic reason underlying horizontal velocity errors in detail and a relevant new calibration method is designed. Experimental results show that after calibration and compensation, the fluctuation and stages in the velocity curve disappear and velocity precision is improved. PMID:26225983

  2. An Overview of the Joint Polar Satellite System (JPSS Science Data Product Calibration and Validation

    Directory of Open Access Journals (Sweden)

    Lihang Zhou

    2016-02-01

    Full Text Available The Joint Polar Satellite System (JPSS will launch its first JPSS-1 satellite in early 2017. The JPSS-1 and follow-on satellites will carry aboard an array of instruments including the Visible Infrared Imaging Radiometer Suite (VIIRS, the Cross-track Infrared Sounder (CrIS, the Advanced Technology Microwave Sounder (ATMS, and the Ozone Mapping and Profiler Suite (OMPS. These instruments are similar to the instruments currently operating on the Suomi National Polar-orbiting Partnership (S-NPP satellite. In preparation for the JPSS-1 launch, the JPSS program at the Center for Satellite Applications and Research (JSTAR Calibration/Validation (Cal/Val teams, have laid out the Cal/Val plans to oversee JPSS-1 science products’ algorithm development efforts, verification and characterization of these algorithms during the pre-launch period, calibration and validation of the products during post-launch, and long-term science maintenance (LTSM. In addition, the team has developed the necessary schedules, deliverables and infrastructure for routing JPSS-1 science product algorithms for operational implementation. This paper presents an overview of these efforts. In addition, this paper will provide insight into the processes of both adapting S-NPP science products for JPSS-1 and performing upgrades for enterprise solutions, and will discuss Cal/Val processes and quality assurance procedures.

  3. Precise cloning and tandem integration of large polyketide biosynthetic gene cluster using Streptomyces artificial chromosome system

    OpenAIRE

    Nah, Hee-Ju; Woo, Min-Woo; Choi, Si-Sun; Kim, Eung-Soo

    2015-01-01

    Background Direct cloning combined with heterologous expression of a secondary metabolite biosynthetic gene cluster has become a useful strategy for production improvement and pathway modification of potentially valuable natural products present at minute quantities in original isolates of actinomycetes. However, precise cloning and efficient overexpression of an entire biosynthetic gene cluster remains challenging due to the ineffectiveness of current genetic systems in manipulating large-si...

  4. A Novel Error Model of Optical Systems and an On-Orbit Calibration Method for Star Sensors

    Directory of Open Access Journals (Sweden)

    Shuang Wang

    2015-12-01

    Full Text Available In order to improve the on-orbit measurement accuracy of star sensors, the effects of image-plane rotary error, image-plane tilt error and distortions of optical systems resulting from the on-orbit thermal environment were studied in this paper. Since these issues will affect the precision of star image point positions, in this paper, a novel measurement error model based on the traditional error model is explored. Due to the orthonormal characteristics of image-plane rotary-tilt errors and the strong nonlinearity among these error parameters, it is difficult to calibrate all the parameters simultaneously. To solve this difficulty, for the new error model, a modified two-step calibration method based on the Extended Kalman Filter (EKF and Least Square Methods (LSM is presented. The former one is used to calibrate the main point drift, focal length error and distortions of optical systems while the latter estimates the image-plane rotary-tilt errors. With this calibration method, the precision of star image point position influenced by the above errors is greatly improved from 15.42% to 1.389%. Finally, the simulation results demonstrate that the presented measurement error model for star sensors has higher precision. Moreover, the proposed two-step method can effectively calibrate model error parameters, and the calibration precision of on-orbit star sensors is also improved obviously.

  5. Surface applicator calibration and commissioning of an electronic brachytherapy system for nonmelanoma skin cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Rong, Yi; Welsh, James S. [Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792 and University of Wisconsin Cancer Center-Riverview, Riverview Hospital Association, Wisconsin Rapids, Wisconsin 54494 (United States); Department of Human Oncology and Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792 and University of Wisconsin Cancer Center-Riverview, Riverview Hospital Association, Wisconsin Rapids, Wisconsin 54494 (United States)

    2010-10-15

    Purpose: The Xoft Axxent x-ray source has been used for treating nonmelanoma skin cancer since the surface applicators became clinically available in 2009. The authors report comprehensive calibration procedures for the electronic brachytherapy (eBx) system with the surface applicators. Methods: The Xoft miniature tube (model S700) generates 50 kVp low-energy x rays. The new surface applicators are available in four sizes of 10, 20, 35, and 50 mm in diameter. The authors' tests include measurements of dose rate, air-gap factor, output stability, depth dose verification, beam flatness and symmetry, and treatment planning with patient specific cutout factors. The TG-61 in-air method was used as a guideline for acquiring nominal dose-rate output at the skin surface. A soft x-ray parallel-plate chamber (PTW T34013) and electrometer was used for the output commissioning. GafChromic EBT films were used for testing the properties of the treatment fields with the skin applicators. Solid water slabs were used to verify the depth dose and cutout factors. Patients with basal cell or squamous cell carcinoma were treated with eBx using a calibrated Xoft system with the low-energy x-ray source and the skin applicators. Results: The average nominal dose-rate output at the skin surface for the 35 mm applicator is 1.35 Gy/min with {+-}5% variation for 16 sources. The dose-rate output and stability (within {+-}5% variation) were also measured for the remaining three applicators. For the same source, the output variation is within 2%. The effective source-surface distance was calculated based on the air-gap measurements for four applicator sizes. The field flatness and symmetry are well within 5%. Percentage depth dose in water was provided by factory measurements and can be verified using solid water slabs. Treatment duration was calculated based on the nominal dose rate, the prescription fraction size, the depth dose percentage, and the cutout factor. The output factor needs

  6. PCR typing of DNA fragments of the two short tandem repeat (STR) systems upstream of the human myelin basic protein (MBP) gene in Danes and Greenland Eskimos

    DEFF Research Database (Denmark)

    Nellemann, L J; Frederiksen, J; Morling, N

    1996-01-01

    DNA from the double short tandem repeat (STR) system MBP (locus 18q23-pter) was amplified by the polymerase chain reaction (PCR) and the two polymorphic repeat systems were separated by cutting with the restriction enzyme NlaIII. The lengths of the DNA fragments of the two MBP STR systems MBP......-A and MBP-B were analyzed by vertical electrophoresis in polyacrylamide gels followed by silver staining. DNA samples from 112 unrelated Danes, 140 unrelated Greenland Eskimos, and 88 Danish mother/child pairs were analyzed. The distributions of MBP phenotypes were in Hardy-Weinberg equilibrium in both...

  7. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications

    Directory of Open Access Journals (Sweden)

    Basam Musleh

    2016-09-01

    Full Text Available Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels and the vehicle environment (meters depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments.

  8. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications.

    Science.gov (United States)

    Musleh, Basam; Martín, David; Armingol, José María; de la Escalera, Arturo

    2016-01-01

    Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels) and the vehicle environment (meters) depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments. PMID:27649178

  9. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications

    Science.gov (United States)

    Musleh, Basam; Martín, David; Armingol, José María; de la Escalera, Arturo

    2016-01-01

    Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels) and the vehicle environment (meters) depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments. PMID:27649178

  10. An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers

    International Nuclear Information System (INIS)

    Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class

  11. An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers.

    Science.gov (United States)

    Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi

    2013-07-01

    Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class. PMID:23902112

  12. World Calibration Center for SF6 – supporting the quality system of the global atmosphere observation

    Directory of Open Access Journals (Sweden)

    W. Yun

    2012-10-01

    Full Text Available According to the World Meteorological Organization (WMO Global Atmosphere Watch (GAW Strategic Plan: 2008–2015 (WMO, 2009a WMO/GAW pays attention to systematical improvement of the quality of observations at global or regional monitoring sites. To ensure the comparability and compatibility of the measurements worldwide it is essential to maintain a traceability chain to the primary standard in the different laboratories around the world as well as to establish a quality control system. Sulfur hexafluoride (SF6, is reported to be very rare in the atmosphere at the global averaged annual mole fraction of about 7 ppt, it is one of the greenhouse gases regulated by Kyoto protocol and is increasing at a rate of 0.22 ppt yr−1. Development of a working (or transfer standard with very low concentration of SF6 requires expert technologies and several knowhow of gas metrology. In order to meet the Data Quality Objective (DQO, the KMA has cooperated with the Korea Research Institute of Standards and Science (KRISS, which is the National Metrology Institute in South Korea. So long as the Central Calibration Laboratory (CCL for SF6 was established, the Korea Meteorological Administration (KMA is now trying to take another step forward to systematically support GAW stations in improving their traceability and quality system for SF6, thereby making a contribution to the WMO/GAW. Through hosting the World Calibration Center for SF6, which is one of GAW facilities, KMA will contribute to harmonization of the global SF6 observations in the long run. This work performed to demonstrate some measurement results on SF6 which complies with the DQOs and is traceable to the WMO mole fraction scale for SF6. In order to produce a working standard which is traceable to the WMO scale, we developed highly precise method of a Gas Chromatography/Electron Capture Detector (GC/ECD calibrated against the five cylinders (from NOAA, 2011 of the WMO scale. For all analysis the

  13. World Calibration Center for SF6 - supporting the quality system of the global atmosphere observation

    Science.gov (United States)

    Lee, J.; Moon, D.; Min, D.; Yun, W.

    2012-10-01

    According to the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) Strategic Plan: 2008-2015 (WMO, 2009a) WMO/GAW pays attention to systematical improvement of the quality of observations at global or regional monitoring sites. To ensure the comparability and compatibility of the measurements worldwide it is essential to maintain a traceability chain to the primary standard in the different laboratories around the world as well as to establish a quality control system. Sulfur hexafluoride (SF6), is reported to be very rare in the atmosphere at the global averaged annual mole fraction of about 7 ppt, it is one of the greenhouse gases regulated by Kyoto protocol and is increasing at a rate of 0.22 ppt yr-1. Development of a working (or transfer) standard with very low concentration of SF6 requires expert technologies and several knowhow of gas metrology. In order to meet the Data Quality Objective (DQO), the KMA has cooperated with the Korea Research Institute of Standards and Science (KRISS), which is the National Metrology Institute in South Korea. So long as the Central Calibration Laboratory (CCL) for SF6 was established, the Korea Meteorological Administration (KMA) is now trying to take another step forward to systematically support GAW stations in improving their traceability and quality system for SF6, thereby making a contribution to the WMO/GAW. Through hosting the World Calibration Center for SF6, which is one of GAW facilities, KMA will contribute to harmonization of the global SF6 observations in the long run. This work performed to demonstrate some measurement results on SF6 which complies with the DQOs and is traceable to the WMO mole fraction scale for SF6. In order to produce a working standard which is traceable to the WMO scale, we developed highly precise method of a Gas Chromatography/Electron Capture Detector (GC/ECD) calibrated against the five cylinders (from NOAA, 2011) of the WMO scale. For all analysis the measurement

  14. Towards a full Atmospheric Calibration system for the Cherenkov Telescope Array

    CERN Document Server

    Doro, M; Blanch, O; Font, LL; Garrido, D; Lopez-Oramas, A

    2013-01-01

    The current generation of Cherenkov telescopes is mainly limited in their gamma-ray energy and flux reconstruction by uncertainties in the determination of atmospheric parameters. The Cherenkov Telescope Array (CTA) aims to provide high-precision data extending the duty cycle as much as possible. To reach this goal, it is necessary to continuously and precisely monitor the atmosphere by means of remote-sensing devices, which are able to provide altitude-resolved and wavelength-dependent extinction factors, sensitive up to the tropopause and higher. Raman LIDARs are currently the best suited technology to achieve this goal with one single instrument. However, the synergy with other instruments like radiometers, solar and stellar photometers, all-sky cameras, and possibly radio-sondes is desirable in order to provide more precise and accurate results, and allows for weather forecasts and now-casts. In this contribution, we will discuss the need and features of such multifaceted atmospheric calibration systems.

  15. Presentation, calibration and validation of the low-order, DCESS Earth System Model

    DEFF Research Database (Denmark)

    Shaffer, G.; Olsen, S. Malskaer; Pedersen, Jens Olaf Pepke

    2008-01-01

    concentrations. The land biosphere module considers leaves, wood, litter and soil. Net primary production depends on atmospheric carbon dioxide concentration and remineralization rates in the litter and soil are related to mean atmospheric temperatures. Methane production is a small fraction of the soil...... in the ocean surface layer depends on phosphate availability but with lower efficiency in the high latitude zone, as determined by model fit to ocean data. The calcite to organic carbon rain ratio depends on surface layer temperature. The semi-analytical, ocean sediment module considers calcium carbonate...... remineralization. The lithosphere module considers outgassing, weathering of carbonate and silicate rocks and weathering of rocks containing old organic carbon and phosphorus. Weathering rates are related to mean atmospheric temperatures. A pre-industrial, steady state calibration to Earth system data is carried...

  16. In-flight calibration of STEREO-B/WAVES antenna system

    CERN Document Server

    Panchenko, M; Rucker, H O; Fischer, G; Oswald, T H; Cecconi, B; Maksimovic, M

    2015-01-01

    The STEREO/WAVES (SWAVES) experiment on board the two STEREO spacecraft (Solar Terrestrial Relations Observatory) launched on 25 October 2006 is dedicated to the measurement of the radio spectrum at frequencies between a few kilohertz and 16 MHz. The SWAVES antenna system consists of 6 m long orthogonal monopoles designed to measure the electric component of the radio waves. With this configuration direction finding of radio sources and polarimetry (analysis of the polarization state) of incident radio waves is possible. For the evaluation of the SWAVES data the receiving properties of the antennas, distorted by the radiation coupling with the spacecraft body and other onboard devices, have to be known accurately. In the present context, these properties are described by the antenna effective length vectors. We present the results of an in-flight calibration of the SWAVES antennas using the observations of the nonthermal terrestrial auroral kilometric radiation (AKR) during STEREO roll maneuvers in an early s...

  17. Color Calibration for Colorized Vision System with Digital Sensor and LED Array Illuminator

    Directory of Open Access Journals (Sweden)

    Zhenmin Zhu

    2016-01-01

    Full Text Available Color measurement by the colorized vision system is a superior method to achieve the evaluation of color objectively and continuously. However, the accuracy of color measurement is influenced by the spectral responses of digital sensor and the spectral mismatch of illumination. In this paper, two-color vision system illuminated by digital sensor and LED array, respectively, is presented. The Polynomial-Based Regression method is applied to solve the problem of color calibration in the sRGB and CIE  L⁎a⁎b⁎ color spaces. By mapping the tristimulus values from RGB to sRGB color space, color difference between the estimated values and the reference values is less than 3ΔE. Additionally, the mapping matrix ΦRGB→sRGB has proved a better performance in reducing the color difference, and it is introduced subsequently into the colorized vision system proposed for a better color measurement. Necessarily, the printed matter of clothes and the colored ceramic tile are chosen as the application experiment samples of our colorized vision system. As shown in the experimental data, the average color difference of images is less than 6ΔE. It indicates that a better performance of color measurement is obtained via the colorized vision system proposed.

  18. The System of the Calibration for Visibility Measurement Instrument Under the Atmospheric Aerosol Simulation Environment

    Directory of Open Access Journals (Sweden)

    Shu Zhifeng

    2016-01-01

    Full Text Available Visibility is one of the most important parameters for meteorological observation and numerical weather prediction (NWP.It is also an important factor in everyday life, mainly for surface and air traffic especially in the Aeronautical Meteorology. The visibility decides the taking off and landing of aircraft. If the airport visibility is lower than requirement for aircraft taking off stipulated by International Civil Aviation Administration, then the aircraft must be parked at the airport. So the accurate measurement of visibility is very important. Nowadays, many devices can be measured the visibility or meteorological optical range (MOR such as Scatterometers, Transmissometers and visibility lidar. But there is not effective way to verify the accuracy of these devices expect the artificial visual method. We have developed a visibility testing system that can be calibration and verification these devices. The system consists of laser transmitter, optical chopper, phase-locking amplifier, the moving optic receiving system, signal detection and data acquisition system, atmospheric aerosol simulation chamber. All of them were placed in the atmosphere aerosol simulation chamber with uniform aerosol concentration. The Continuous wave laser, wavelength 550nm, has been transmitted into the collimation system then the laser beam expanded into 40mm diameter for compressing the laser divergence angle before modulated by optical chopper. The expanding beam transmitting in the atmosphere aerosol cabin received by the optic receiving system moving in the 50m length precision guide with 100mm optical aperture. The data of laser signal has been acquired by phase-locking amplifier every 5 meter range. So the 10 data points can be detected in the 50 meters guide once. The slope of the fitting curve can be obtained by linear fitting these data using the least square method. The laser extinction coefficient was calculated from the slope using the Koschmieder

  19. The System of the Calibration for Visibility Measurement Instrument Under the Atmospheric Aerosol Simulation Environment

    Science.gov (United States)

    Shu, Zhifeng; Yang, ShaoChen; Xu, Wenjing

    2016-06-01

    Visibility is one of the most important parameters for meteorological observation and numerical weather prediction (NWP).It is also an important factor in everyday life, mainly for surface and air traffic especially in the Aeronautical Meteorology. The visibility decides the taking off and landing of aircraft. If the airport visibility is lower than requirement for aircraft taking off stipulated by International Civil Aviation Administration, then the aircraft must be parked at the airport. So the accurate measurement of visibility is very important. Nowadays, many devices can be measured the visibility or meteorological optical range (MOR) such as Scatterometers, Transmissometers and visibility lidar. But there is not effective way to verify the accuracy of these devices expect the artificial visual method. We have developed a visibility testing system that can be calibration and verification these devices. The system consists of laser transmitter, optical chopper, phase-locking amplifier, the moving optic receiving system, signal detection and data acquisition system, atmospheric aerosol simulation chamber. All of them were placed in the atmosphere aerosol simulation chamber with uniform aerosol concentration. The Continuous wave laser, wavelength 550nm, has been transmitted into the collimation system then the laser beam expanded into 40mm diameter for compressing the laser divergence angle before modulated by optical chopper. The expanding beam transmitting in the atmosphere aerosol cabin received by the optic receiving system moving in the 50m length precision guide with 100mm optical aperture. The data of laser signal has been acquired by phase-locking amplifier every 5 meter range. So the 10 data points can be detected in the 50 meters guide once. The slope of the fitting curve can be obtained by linear fitting these data using the least square method. The laser extinction coefficient was calculated from the slope using the Koschmieder formula, then it been

  20. Infrared fluorescent automated detection of thirteen short tandem repeat polymorphisms and one gender-determining system of the CODIS core system.

    Science.gov (United States)

    Ricci, U; Sani, I; Guarducci, S; Biondi, C; Pelagatti, S; Lazzerini, V; Brusaferri, A; Lapini, M; Andreucci, E; Giunti, L; Giovannucci Uzielli, M L

    2000-11-01

    We used an infrared (IR) automated fluorescence monolaser sequencer for the analysis of 13 autosomal short tandem repeat (STR) systems (TPOX, D3S1358, FGA, CSF1PO, D5S818, D7S820, D8S1179, TH01, vWA, D13S317, D16S359, D18S51, D21S11) and the X-Y homologous gene amelogenin system. These two systems represent the core of the combined DNA index systems (CODIS). Four independent multiplex reactions, based on the polymerase chain reaction (PCR) technique and on the direct labeling of the forward primer of every primer pair, with a new molecule (IRDye800), were set up, permitting the exact characterization of the alleles by comparison with ladders of specific sequenced alleles. This is the first report of the whole analysis of the STRs of the CODIS core using an IR automated DNA sequencer. The protocol was used to solve paternity/maternity tests and for population studies. The electrophoretic system also proved useful for the correct typing of those loci differing in size by only 2 bp. A sensibility study demonstrated that the test can detect an average of 10 pg of undegraded human DNA. We also performed a preliminary study analyzing some forensic samples and mixed stains, which suggested the usefulness of using this analytical system for human identification as well as for forensic purposes.

  1. Towards monolithic scintillator based TOF-PET systems: practical methods for detector calibration and operation

    Science.gov (United States)

    Borghi, Giacomo; Tabacchini, Valerio; Schaart, Dennis R.

    2016-07-01

    Gamma-ray detectors based on thick monolithic scintillator crystals can achieve spatial resolutions  PET), the application of monolithic scintillators has so far been hampered by the lengthy and complex procedures needed for position- and time-of-interaction estimation. Here, the algorithms previously developed in our group are revised to make the calibration and operation of a large number of monolithic scintillator detectors in a TOF-PET system practical. In particular, the k-nearest neighbor (k-NN) classification method for x,y-position estimation is accelerated with an algorithm that quickly preselects only the most useful reference events, reducing the computation time for position estimation by a factor of ~200 compared to the previously published k-NN 1D method. Also, the procedures for estimating the DOI and time of interaction are revised to enable full detector calibration by means of fan-beam or flood irradiations only. Moreover, a new technique is presented to allow the use of events in which some of the photosensor pixel values and/or timestamps are missing (e.g. due to dead time), so as to further increase system sensitivity. The accelerated methods were tested on a monolithic scintillator detector specifically developed for clinical PET applications, consisting of a 32 mm  ×  32 mm  ×  22 mm LYSO : Ce crystal coupled to a digital photon counter (DPC) array. This resulted in a spatial resolution of 1.7 mm FWHM, an average DOI resolution of 3.7 mm FWHM, and a CRT of 214 ps. Moreover, the possibility of using events missing the information of up to 16 out of 64 photosensor pixels is shown. This results in only a small deterioration of the detector performance.

  2. Calibration of a PIXE system for analysis of environmental aerosols; Calibracion de un sistema PIXE para analisis de aerosoles ambientales

    Energy Technology Data Exchange (ETDEWEB)

    Aldape, F.; Diaz, R.V.; Anguiano, G.; Flores M, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1991-04-15

    The results of the calibration of the PIXE system for analysis of environmental aerosols in the CNM is presented. The system was calibrated in order to lead to the project study of environmental aerosols using PIXE from the qualitative dimension to the quantitative one. Part of this work it was carried out in collaboration with the expert of the IAEA Dr. D. Crumpton. The calibration of the system it was achieved bombarding thin targets of well-known composition with protons of 2.5 MeV. Using this technique it was determined the absolute elementary concentration in samples of atmospheric aerosols. As an example the calculation of the lead concentration in one of them whose result was of 662 {+-} 49 ng m{sup -3} is presented. This value agrees with the measurements made in the Crocker Nuclear Lab of the UCD. Its are also discussed the reproducibility and precision of the used technique. (Author)

  3. Instructions for calibrating gamma detectors using the Canberra-Nuclear Data Genie Gamma Spectroscopy System

    International Nuclear Information System (INIS)

    A straight forward protocol provides a way to guide the calibration of a gamma detector for a particular geometry and material. Several programs have used the Low Level Gamma Counting Facility of the Health and Ecological Assessment Division of the Lawrence Livermore National Laboratory to count a variety of large environmental samples contained in several unique geometries. The equipment and calibration requirements needed to analyze these types of samples are explained. This document describes the calibration protocol that has been developed and describes how it is used to calibrate the detectors

  4. The monitoring and calibration Web system of the ATLAS hadronic calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Maidantchik, Carmen; Gomes, Andressa Andrea Sivollela; Marroquim, Fernando [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2011-07-01

    Full text: The scintillator tiles hadronic calorimeter (TileCal) of the ATLAS detector measures the energy of resultant particles in a collision. The calorimetry system was designed to absorb the energy of the particles that crosses the detector and is composed by three barrels, each one equally divided into 64 modules. The ionizing particles that cross the tiles induce the production of light, which intensity is proportional to the energy deposited by the fragment. The produced light propagates through the tiles towards the edges, where it is absorbed and displaced until reaching the photomultiplier tubes (PMTs), also known as electronic reading channels. Each module combines till 45 PMTs. For each run, the reconstruction process starts with a data analysis that can comprises different levels of information granularity till arriving to the PMTs level. Following this phase, the Data Quality Monitoring Framework (DQMF) system automatically generates quality indicators associated to the channels. Depending on the configuration that is registered in the DQMF, the channel status can be automatically defined as good, affected or bad. The status of each module is defined by the percentage of existing good, affected or bad channels. At this point, the analysis of modules allows the identification of the ones that are problematic by the examination of graphics that are automatically generated during the data reconstruction stage. Then, an analysis of a module performance by a time period that encompasses different types of runs is performed. In this last step, the list of problematic channels can be modified through the insertion or exclusion of PTMs, as in the case when a channel is substituted. Additionally, during the whole calorimeter operation, it is fundamental to identify the electronic channels that are active, dead (nor working), noisy and the ones that presents saturation in the signal digitalisation process. The Monitoring and Calibration Web System (MCWS) was

  5. [Research on On-Line Calibration Based Photoacoustic Spectrometry System for Monitoring the Concentration of CO2 in Atmosphere].

    Science.gov (United States)

    Zhang, Jian-feng; Pan, Sun-qiang; Lin, Xiao-lu; Hu, Peng-bing; Chen, Zhe-min

    2016-01-01

    Resonate frequency and cell constant of photoacoustic spectrum system are usually calibrated by using standard gas in laboratory, whereas the resonate frequency and cell constant will be changed in-situ, leading to measurement accuracy errors, caused by uncertainties of standard gas, differences between standard and measured gas components and changes in environmental condition, such as temperature and humidity. As to overcome the above problems, we have proposed an on-line atmospheric oxygen-based calibration technology for photoacoustic spectrum system and used in measurement of concentration of carbon dioxide in atmosphere. As the concentration of atmospheric oxygen is kept as constant as 20.96%, the on-line calibration for the photoacoustic spectrum system can be realized by detecting the swept-frequency and peak signal at 763.73 nm. The cell of the PAS has a cavity with length of 100 mm and an inner diameter of 6 mm, and worked in a first longitudinal resonant mode. The influence of environmental temperature and humidity, gas components on the photoacoustic cell's performance has been theoretically analyzed, and meanwhile the resonant frequencies and cell constants were calibrated and acquired respectively using standard gas, indoor air and outdoor air. Compared with calibrated gas analyzer, concentration of carbon dioxide is more accurate by using the resonant frequency and cell constant calculated by oxygen in tested air, of which the relative error is less than 1%, much smaller than that calculated by the standard gas in laboratory. The innovation of this paper is that using atmospheric oxygen as photoacoustic spectrum system's calibration gas effectively reduces the error caused by using standard gas and environmental condition changes, and thus improves the on-line measuring accuracy and reliability of the photoacoustic spectrum system.

  6. Minimizing Intra-Campaign Biases in Airborne Laser Altimetry By Thorough Calibration of Lidar System Parameters

    Science.gov (United States)

    Sonntag, J. G.; Chibisov, A.; Krabill, K. A.; Linkswiler, M. A.; Swenson, C.; Yungel, J.

    2015-12-01

    Present-day airborne lidar surveys of polar ice, NASA's Operation IceBridge foremost among them, cover large geographical areas. They are often compared with previous surveys over the same flight lines to yield mass balance estimates. Systematic biases in the lidar system, especially those which vary from campaign to campaign, can introduce significant error into these mass balance estimates and must be minimized before the data is released by the instrument team to the larger scientific community. NASA's Airborne Topographic Mapper (ATM) team designed a thorough and novel approach in order to minimize these biases, and here we describe two major aspects of this approach. First, we conduct regular ground vehicle-based surveys of lidar calibration targets, and overfly these targets on a near-daily basis during field campaigns. We discuss our technique for conducting these surveys, in particular the measures we take specifically to minimize systematic height biases in the surveys, since these can in turn bias entire campaigns of lidar data and the mass balance estimates based on them. Second, we calibrate our GPS antennas specifically for each instrument installation in a remote-sensing aircraft. We do this because we recognize that the metallic fuselage of the aircraft can alter the electromagnetic properties of the GPS antenna mounted to it, potentially displacing its phase center by several centimeters and biasing lidar results accordingly. We describe our technique for measuring the phase centers of a GPS antenna installed atop an aircraft, and show results which demonstrate that different installations can indeed alter the phase centers significantly.

  7. Calibration of 5-hole Probe for Flow Angles from Advanced Technologies Testing Aircraft System Flight Data

    Directory of Open Access Journals (Sweden)

    Y. Parameswaran

    2004-04-01

    Full Text Available This paper describes the investigations carried out to calibrate the 5-hole probe for flow angles from advanced technologies testing aircraft system flight data. The flight tests were carriedout with gear up and at nominal mid-centre of gravity location for two landing flap positions, Of= IN and 14°. Dynamic manoeuvres were executed to excite the short period and Dutch roll mode of the aircraft. In addition, pull up, push down and steady sideslip manoeuvres were also carried out. The data compatibility check on the recorded flight data has been carried out using maximum likelihood output error algorithm to estimate the bias, scale factor, and time delay in the pressure measurements from the 5-hole probe mounted on a noseboom in front of aircraft nose . Through a way of kinematic consistency checking, flight-validated scale factors, biases, and time delays are determined for the differential pressure measurements for both angle of attack and angle of sideslip. Also, the dynamic pressure measurement is found to have time delays. Based on the earlier investigations, it is once again confirmed that the measurements of attitude angles, obtained from the inertial platform, clearly indicate time delays referred to the other signals like linear accelerations and angular rates which are measured with the dedicated flight instrumentation package.The identified time delays in attitude angles agreed well with the inertial platform specifications. The estimates of sensitivity coefficients and scale factors from the flight data analysis correlates reasonably well with the manufacturer Rosemount calibration curves for the tested Mach range 0.23-0.53 . The flight data analysis at Mach number of about 0.59 indicateMach dependency for the angle of attack.

  8. Calibration and data quality systems of the ATLAS Tile Calorimeter during the LHC Run-I operations

    Science.gov (United States)

    Ženiš, T.

    2016-07-01

    The Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It consists of thin steel plates and scintillating tiles. Wavelength shifting fibers coupled to the tiles collect the produced light and are read out by photomultiplier tubes. The calibration scheme of the Tile Calorimeter comprises Cs radioactive source, laser and charge injection systems. Each stage of the signal production of the calorimeter from scintillation light to digitization is monitored and equalized. Description of the different TileCal calibration systems as well as the results on their performance in terms of calibration factors, linearity and stability is given. The data quality procedures and efficiency of the Tile Calorimeter during the LHC Run-1 data-taking period are presented as well.

  9. Calibration and Data Quality systems of the ATLAS Tile Calorimeter during the LHC Run-I operations

    CERN Document Server

    Zenis, Tibor; The ATLAS collaboration

    2015-01-01

    The Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It consists of thin steel plates and scintillating tiles. Wavelength shifting fibres coupled to the tiles collect the produced light and are read out by photomultiplier tubes. The calibration scheme of the Tile Calorimeter comprises Cs radioactive source, laser and charge injection systems. Each stage of the signal production of the calorimeter from scintillation light to digitization is monitored and equalized. Description of the different TileCal calibration systems as well as results on their performance in terms of calibration factors, linearity and stability will be given. The data quality procedures and data quality efficiency of the Tile Calorimeter during the LHC data-taking period are presented as well.

  10. Calibration and Data Quality systems of the ATLAS Tile Calorimeter during the LHC Run-I operations

    CERN Document Server

    Zenis, Tibor; The ATLAS collaboration

    2015-01-01

    The Tile Calorimeter is the hadronic calorimeter covering the central region of the ATLAS detector at the LHC. It consists of thin steel plates and scintillating tiles. Wavelength shifting fibres coupled to the tiles collect the produced light and are read out by photomultiplier tubes. The calibration scheme of the Tile Calorimeter comprises Cs radioactive source, laser and charge injection systems. Each stage of the signal production of the calorimeter from scintillation light to digitization is monitored and equalized. Description of the different TileCal calibration systems as well as the results on their performance in terms of calibration factors, linearity and stability are given. The data quality procedures and data quality efficiency of the Tile Calorimeter during the LHC data-taking period are presented as well.

  11. Metrology system for the calibration of multi-dof precision mechanisms

    Science.gov (United States)

    Zago, Lorenzo; Sarajlic, Mirsad; Chevalley, Fabien; Yang, Dehua

    2012-09-01

    We have developed a novel metrology system for precision XY measurements based on a concept developed originally in an industrial vision context by which USB cameras observe a target with a special dots pattern. The system has then been extended to Rx-Ry (tip-tilt), Z and Rz measurements by adding more cameras within a suitable configuration. The basic principle is described, first validated on a preliminary experimental implementation used for testing a new type of hexapod. We then illustrate the setup designed as calibration bench for hexapods used as positioning devices of the secondary mirrors of astronomical telescopes. While work is still ongoing for improving this new metrology system, currently achieved performances are a stability of is <=1 μm along linear degrees of freedom, respectively 0.5 arcsec for tip-tilt; absolute accuracy over ranges of a few millimeters is 5-10 μm , respectively arcsec; incremental accuracy is 2-3 μm, respectively 5 arcsec.

  12. View-dependent geometric calibration for offset flat-panel cone beam computed tomography systems

    Science.gov (United States)

    Nguyen, Van-Giang

    2016-04-01

    Geometric parameters that define the geometry of imaging systems are crucial for image reconstruction and image quality in x-ray computed tomography (CT). The problem of determining geometric parameters for an offset flat-panel cone beam CT (CBCT) system, a recently introduced modality with a large field of view, with the assumption of an unstable mechanism and geometric parameters that vary in each view, is considered. To accurately and rapidly find the geometric parameters for each projection view, we use the projection matrix method and design a dedicated phantom that is partially visible in all projection views. The phantom consists of balls distributed symmetrically in a cylinder to ensure the inclusion of the phantom in all views, and a large portion of the phantom is covered in the projection image. To efficiently use calibrated geometric information in the reconstruction process and get rid of approximation errors, instead of decomposing the projection matrix into actual geometric parameters that are manually corrected before being used in reconstruction, as in conventional methods, we directly use the projection matrix and its pseudo-inverse in projection and backprojection operations of reconstruction algorithms. The experiments illustrate the efficacy of the proposed method with a real offset flat-panel CBCT system in dental imaging.

  13. Science Data System Contribution to Calibrating and Validating SMAP Data Products

    Science.gov (United States)

    Cuddy, D.

    2015-12-01

    NASA's Soil Moisture Active Passive (SMAP) mission retrieves global surface soil moisture and freeze/thaw state using measurements acquired by a radiometer and a synthetic aperture radar that fly on an Earth orbiting satellite. The SMAP observatory launched from Vandenberg Air Force Base on January 31, 2015 into a near-polar, sun-synchronous orbit. This paper describes the contribution of the SMAP Science Data System (SDS) to the calibration and on-going validation of the radar backscatter and radiometer brightness temperatures. The Science Data System designed, implemented and operated the software that generates data products that contain various geophysical parameters including soil moisture and freeze/thaw states, daily maps of these geophysical parameters, as well as modeled analyses of global soil moisture and carbon flux in Boreal regions. The SDS is a fully automated system that processes the incoming raw data from the instruments, incorporates spacecraft and instrument engineering data, and uses both dynamic and static ancillary products provided by the scientific community. The standard data products appear in Hierarchical Data Format-5 (HDF5) format. These products contain metadata that conform to the ISO 19115 standard. The Alaska Satellite Facility (ASF) hosts and distributes SMAP radar data products. The National Snow and Ice Data Center (NSIDC) hosts and distributes all of the other SMAP data products.

  14. Point Cloud Refinement with a Target-Free Intrinsic Calibration of a Mobile Multi-Beam LIDAR System

    Science.gov (United States)

    Nouiraa, H.; Deschaud, J. E.; Goulettea, F.

    2016-06-01

    LIDAR sensors are widely used in mobile mapping systems. The mobile mapping platforms allow to have fast acquisition in cities for example, which would take much longer with static mapping systems. The LIDAR sensors provide reliable and precise 3D information, which can be used in various applications: mapping of the environment; localization of objects; detection of changes. Also, with the recent developments, multi-beam LIDAR sensors have appeared, and are able to provide a high amount of data with a high level of detail. A mono-beam LIDAR sensor mounted on a mobile platform will have an extrinsic calibration to be done, so the data acquired and registered in the sensor reference frame can be represented in the body reference frame, modeling the mobile system. For a multibeam LIDAR sensor, we can separate its calibration into two distinct parts: on one hand, we have an extrinsic calibration, in common with mono-beam LIDAR sensors, which gives the transformation between the sensor cartesian reference frame and the body reference frame. On the other hand, there is an intrinsic calibration, which gives the relations between the beams of the multi-beam sensor. This calibration depends on a model given by the constructor, but the model can be non optimal, which would bring errors and noise into the acquired point clouds. In the litterature, some optimizations of the calibration parameters are proposed, but need a specific routine or environment, which can be constraining and time-consuming. In this article, we present an automatic method for improving the intrinsic calibration of a multi-beam LIDAR sensor, the Velodyne HDL-32E. The proposed approach does not need any calibration target, and only uses information from the acquired point clouds, which makes it simple and fast to use. Also, a corrected model for the Velodyne sensor is proposed. An energy function which penalizes points far from local planar surfaces is used to optimize the different proposed parameters

  15. Three-dimensional surface imaging by multi-frequency phase shift profilometry with angle and pattern modeling for system calibration

    Science.gov (United States)

    Wang, Zhenzhou

    2016-08-01

    In this paper, we present a 3D surface imaging system based on the well-known phase shift profilometry. To yield the analytical solutions, four shifted phases and three high carrier frequencies are used to compute the phase map and reduce the noises that are caused by the inherent optical aberrations and external influences, e.g. different illumination light sources, uneven intensity distribution and automatic image processing algorithms. To reduce the system noise, we propose to model the pattern of the calibration grid in a virtual space. To obtain the modeled pattern, we use a plane to intercept the rays that are modeled by the proposed angle modeling method. In the world coordinate system, the angle and the pattern are computed based on the calibration data. A registration method is used to transform the modeled pattern in the virtual space to the ideal pattern in the world coordinate system by computing the least squared errors between the true points in the modeled pattern and the measured points in the practical pattern. The modeled (true) points are used for re-calibration of the 3D imaging system. Experimental results showed that the measurement accuracy increases considerably and the MSE is reduced from 0.95 mm to 0.65 mm (32% average error decrease) after replacing the measured points with the true points for calibration.

  16. Construction of modular tandem expression vectors for the green alga Chlamydomonas reinhardtii using the Cre/lox-system.

    Science.gov (United States)

    Heitzer, Markus; Zschoernig, Barbara

    2007-09-01

    The successful expression of foreign genes mainly depends on both a reliable method for transformation and a suitable promoter sequence. We created a series of modular plasmids that facilitate the rapid construction of large tandem vectors for transgene expression under the control of different promoter sequences in Chlamydomonas reinhardtii. Tandem vectors carrying expression cassettes for Renilla luciferase and a metabolic selection marker (ARG7) were manufactured by fusing two plasmids in vitro using Cre/lox site-specific recombination. Supercoiled and linear plasmids were used to transform an arginine auxotrophic Chlamydomonas strain, and rates of co-expression as well as levels of luciferase activity were monitored for frequently used promoters (HSP70A, LHCB1, PSAD, and the chimeric HSP70A/RBCS2). Linearized tandem vectors generally increased the co-expression frequency (up to 77%) compared with standard cotransformation protocols. Most transformants showed a single and complete integration event confirming the close linkage of active selectable marker and reporter gene within the nuclear genome. The analysis of luciferase activity showed expression levels within three orders of magnitude for the promoters used, with the artificial HSP70A/RRBCS2 being the most active. For 69% of all luminescent transformants carrying the HSP70A promoter luciferase expression was enhanced by heatshock, indicating physiological promoter function in a transgenic context.

  17. Trinocular Calibration Method Based on Binocular Calibration

    Directory of Open Access Journals (Sweden)

    CAO Dan-Dan

    2012-10-01

    Full Text Available In order to solve the self-occlusion problem in plane-based multi-camera calibration system and expand the measurement range, a tri-camera vision system based on binocular calibration is proposed. The three cameras are grouped into two pairs, while the public camera is taken as the reference to build the global coordinate. By calibration of the measured absolute distance and the true absolute distance, global calibration is realized. The MRE (mean relative error of the global calibration of the two camera pairs in the experiments can be as low as 0.277% and 0.328% respectively. Experiment results show that this method is feasible, simple and effective, and has high precision.

  18. Retrievals of Thick Cloud Optical Depth from the Geoscience Laser Altimeter System (GLAS) by Calibration of Solar Background Signal

    Science.gov (United States)

    Yang, Yuekui; Marshak, Alexander; Chiu, J. Christine; Wiscombe, Warren J.; Palm, Stephen P.; Davis, Anthony B.; Spangenberg, Douglas A.; Nguyen, Louis; Spinhirne, James D.; Minnis, Patrick

    2008-01-01

    Laser beams emitted from the Geoscience Laser Altimeter System (GLAS), as well as other space-borne laser instruments, can only penetrate clouds to a limit of a few optical depths. As a result, only optical depths of thinner clouds (thick clouds using solar background light and treating GLAS as a solar radiometer. To do so we first calibrate the reflected solar radiation received by the photon-counting detectors of GLAS' 532 nm channel, which is the primary channel for atmospheric products. The solar background radiation is regarded as a noise to be subtracted in the retrieval process of the lidar products. However, once calibrated, it becomes a signal that can be used in studying the properties of optically thick clouds. In this paper, three calibration methods are presented: (I) calibration with coincident airborne and GLAS observations; (2) calibration with coincident Geostationary Operational Environmental Satellite (GOES) and GLAS observations of deep convective clouds; (3) calibration from the first principles using optical depth of thin water clouds over ocean retrieved by GLAS active remote sensing. Results from the three methods agree well with each other. Cloud optical depth (COD) is retrieved from the calibrated solar background signal using a one-channel retrieval. Comparison with COD retrieved from GOES during GLAS overpasses shows that the average difference between the two retrievals is 24%. As an example, the COD values retrieved from GLAS solar background are illustrated for a marine stratocumulus cloud field that is too thick to be penetrated by the GLAS laser. Based on this study, optical depths for thick clouds will be provided as a supplementary product to the existing operational GLAS cloud products in future GLAS data releases.

  19. Performance evaluation of the reference system for calibration of IPEN activities

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Elaine Wirney; Potiens, Maria da Penha A., E-mail: ewmartins@ipen.br, E-mail: mppalbu@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The formation of good quality image in nuclear medicine services depends on several factors, including the radiopharmaceutical activity, which must be well determined by a specific apparatus, in perfect operating condition, called activimeter. Therefore, the establishment of a quality control program for measuring the radiopharmaceuticals radioactivity before being administered to the patient is crucial to the safe and effective use of the radiopharmaceuticals used in diagnostic and therapeutical procedures. Two activimeters, belonging by the Laboratorio de Calibracao do Instrumentos (LCI) of Instituto de Pesquisas Energeticas e Nucleares (IPEN), were evaluated: the secondary standard system NPL-CRC radionuclide calibrator, manufactured by Southern Scientific, and the work standard system CRC-15BT with traceability to National Institute of Standard and Technology (NIST). A set of standard sources of the radionuclides {sup 1}'3{sup 3}Ba, {sup 57}Co and {sup 137}Cs was used as reference to perform the quality control tests. The precision, accuracy and repeatability tests were in agreement with those established by the CNEN-NE 3.05 Brazilian standard, which recommends the variation limit of up to 10%, 5% and 5% respectively. The results obtained for the reproducibility tests presented a variation always below 1,5%, which means it is within the IEC 61674 international standard recommendation of up to 3%. Activimeters response regarding linearity showed concordance between the measured activities and the theoretical curve for both activimeters. (author)

  20. A comparison between two Brazilian calibration systems for diagnostic radiology level

    International Nuclear Information System (INIS)

    A very important step in a quality control program, at calibration laboratories, is the establishment of laboratory intercomparisons. In this work, a comparison between the calibration laboratories of IPEN/CNEN-SP and CDTN/CNEN-MG was carried out, as part of the quality control program in the metrological network established by the project 'National Institutes of Science and Technology - Radiation Metrology in Medicine'. The comparisons were undertaken for direct and attenuated diagnostic radiology quality beams RQR and RQA. The results showed a good agreement between both calibration laboratories. (author)

  1. Calibration transfer between electronic nose systems for rapid In situ measurement of pulp and paper industry emissions

    International Nuclear Information System (INIS)

    Highlights: • E-nose developed for obnoxious emissions measurement at pulp and paper industrial site. • ANN model developed for prediction of (CH3)2S, (CH3)2S2, CH3SH and H2S concentration. • Calibration transfer methodology developed for transfer between two e-nose instruments. • Box–Behnken design and robust regression used for calibration transfer. • Results show effective transfer of training model from one e-nose system to other. - Abstract: Electronic nose systems when deployed in network mesh can effectively provide a low budget and onsite solution for the industrial obnoxious gaseous measurement. For accurate and identical prediction capability by all the electronic nose systems, a reliable calibration transfer model needs to be implemented in order to overcome the inherent sensor array variability. In this work, robust regression (RR) is used for calibration transfer between two electronic nose systems using a Box–Behnken (BB) design. Out of the two electronic nose systems, one was trained using industrial gas samples by four artificial neural network models, for the measurement of obnoxious odours emitted from pulp and paper industries. The emissions constitute mainly of hydrogen sulphide (H2S), methyl mercaptan (MM), dimethyl sulphide (DMS) and dimethyl disulphide (DMDS) in different proportions. A Box–Behnken design consisting of 27 experiment sets based on synthetic gas combinations of H2S, MM, DMS and DMDS, were conducted for calibration transfer between two identical electronic nose systems. Identical sensors on both the systems were mapped and the prediction models developed using ANN were then transferred to the second system using BB–RR methodology. The results showed successful transmission of prediction models developed for one system to other system, with the mean absolute error between the actual and predicted concentration of analytes in mg L−1 after calibration transfer (on second system) being 0.076, 0.1801, 0.0329, 0

  2. A balanced calibration of water quantity and quality by multi-objective optimization for integrated water system model

    Science.gov (United States)

    Zhang, Yongyong; Shao, Quanxi; Taylor, John A.

    2016-07-01

    Due to the high interactions among multiple processes in integrated water system models, it is extremely difficult, if not impossible, to achieve reasonable solutions for all objectives by using the traditional step-by-step calibration. In many cases, water quantity and quality are equally important but their objectives in model calibration usually conflict with each other, so it is not a good practice to calibrate one after another. In this study, a combined auto-calibration multi-process approach was proposed for the integrated water system model (HEQM) using a multi-objective evolutionary algorithm. This ensures that the model performance among inseparable or interactive processes could be balanced by users based on the Pareto front. The Huai River Basin, a highly regulated and heavily polluted region of China, was selected as a case study. The hydrological and water quality parameters of HEQM were calibrated simultaneously based on the observed series of runoff and ammonia-nitrogen (NH4-N) concentrations. The results were compared with those of the step-by-step calibration to demonstrate the rationality and feasibility of the multi-objective approach. The results showed that a Pareto optimal front was formed and could be divided into three clear sections based on the elastic coefficient of model performance between NH4-N and runoff, i.e., the dominated section for NH4-N improvement, the trade-off section between NH4-N and runoff, and the dominated section for runoff improvement. The trade-off of model performance between runoff and NH4-N concentration was clear. The results of the step-by-step calibration fell in the dominated section for NH4-N improvement, where just the optimum of the runoff simulation was achieved with a large potential to improve NH4-N simulation without a significant degradation of the runoff simulation. The overall optimal solutions for all the simulations appeared in the trade-off section. Therefore, the Pareto front provided different

  3. [Multisite-based approach to assure inter-assay system compatibility among different exclusive-typed immunoassay systems through determining exchanged calibrators].

    Science.gov (United States)

    Yamauchi, Megumi S; Yamane, Nobuhisa; Toshimitsu, Shoji; Sato, Hisatsune; Fujino, Tatsuya

    2010-01-01

    It is well known that most exclusive-typed immunoassay systems are highly precise but are poor in compatibility of their determinations. Thus, it is difficult to compare the determinations among different systems, posing problems when a patient is transferred to different hospitals or when a laboratory intends to change the system currently used. In the study, we tried to approach how to assure inter-immunoassay compatibility among four different systems through determination of the exchanged calibrators. First, determinations of total protein and albumin, and electrophoretic fractionation demonstrated marked differences among calibrators in their protein constituent. Some calibrators were prepared with human sera, but others were with inorganic or non-human albumin-based solution. Regression analysis of calibrators between the indicated concentrations by manufacturers and those actually determined by the different immunoassay systems revealed that; most slopes were closed to 1.0 for alpha-fetoprotein and prostate-specific antigen, but widely dissociated from 0.28 to 4.71 for CA19-9. In evaluation of clinical serum samples, determinations by one immunoassay system were compared with those converted based on a linear regression equation that was obtained by determination of the exchanged calibrators. However, this procedure could not improve compatibility, and positive effects of conversion varied by immunoassay systems combined, and also by test parameters. With these, we concluded that simple conversion of determinations by using the exchanged calibrators and a statistical linear regression could not provide us with the expected compatibility. Thus, standardization of target molecules or probes, and of calibrator constituent were urgent issue to assure inter-immunoassay compatibility. PMID:20169939

  4. Development and Uncertainty Evaluation of Calibrating System for Digital Energy Setting

    Directory of Open Access Journals (Sweden)

    Zhao Sha

    2016-01-01

    Full Text Available The power measurement mode has made fundamental changes with the development of smart substation, traditional energy metering analog devices are replaced by digital devices according to the requirements of digitalized information substation. Creating traceability between digital measuring value and analog measuring value and developing relevant calibration devices are key issues in smart substation construction. A new device for calibration digital energy meters using integral calibration technology is described in this paper. Based on the Standard Comparison Method, the device establishes a connection between the digital power and the traditional analog power with the integral calibration technology, and solves the problem that digital power was not able to be traced. The device is designed with final measuring voltage level: 220kV/110kV, measuring current range: 5A~5000A, and extended uncertainty less than 0.05%. Furthermore, the estimating process of the uncertainty of the device is discussed emphatically.

  5. Calibration of robot tool centre point using camera-based system

    Directory of Open Access Journals (Sweden)

    Gordić Zaviša

    2016-01-01

    Full Text Available Robot Tool Centre Point (TCP calibration problem is of great importance for a number of industrial applications, and it is well known both in theory and in practice. Although various techniques have been proposed for solving this problem, they mostly require tool jogging or long processing time, both of which affect process performance by extending cycle time. This paper presents an innovative way of TCP calibration using a set of two cameras. The robot tool is placed in an area where images in two orthogonal planes are acquired using cameras. Using robust pattern recognition, even deformed tool can be identified on images, and information about its current position and orientation forwarded to control unit for calibration. Compared to other techniques, test results show significant reduction in procedure complexity and calibration time. These improvements enable more frequent TCP checking and recalibration during production, thus improving the product quality.

  6. Calibrating the Helium Pressurization System for the Space Shuttle Liquid-Hydrogen Tank

    Science.gov (United States)

    2008-01-01

    Analysis of the results from the STS-114 tanking tests and subsequent launch called into question existing thermal and mass models of helium pressurization of the liquid hydrogen tank. This hydrogen tank, which makes up the bottom two-thirds of the External Tank, is pressurized prior to launch to avoid cavitation in the Shuttle Main Engine pumps. At about 2 minutes prior to launch, the main vent valve is closed, and pressurized helium flows into the tank ullage space to achieve set point pressure. As the helium gas cools, its pressure drops, calling for additional helium. Subsequent helium flows are provided in short, timed pulses. The number of pulses is taken as a rough leak indicator. An analysis of thermal models by Marshall Space Flight Center showed considerable uncertainty in the pressure-versus-time behavior of the helium ullage space and the ability to predict the number of pulses normally expected. Kennedy Space Center proposed to calibrate the dime-sized orifice, which together with valves, controls the helium flow quantity (Figure 1). Pressure and temperature sensors were installed to provide upstream and downstream measurements necessary to compute flow rate based on the orifice discharge coefficient. An assessment of flow testing with helium indicated an extremely costly use of this critical resource. In order to reduce costs, we proposed removing the orifices from each Mobile Launcher Platform (MLP) and asking Colorado Engineering Experiment Station Inc. (CEESI) to calibrate the flow. CEESI has a high-pressure air flow system with traceable flow meters capable of handling the large flow rates. However, literature research indicated that square-edged orifices of small diameters often exhibit significant hysteresis and nonrepeatability in the vicinity of choked or sonic flow. Fortunately, the MLP orifices behaved relatively well in testing (Figure 2). Using curve fitting of the air-flow data, in conjunction with ASME orifice modeling equations, a

  7. Absolute reactivity calibration of accelerator-driven systems after RACE-T experiments

    International Nuclear Information System (INIS)

    The RACE-T experiments that were held in november 2005 in the ENEA-Casaccia research center near Rome allowed us to improve our knowledge of the experimental techniques for absolute reactivity calibration at either startup or shutdown phases of accelerator-driven systems. Various experimental techniques for assessing a subcritical level were inter-compared through three different subcritical configurations SC0, SC2 and SC3, about -0.5, -3 and -6 dollars, respectively. The area-ratio method based of the use of a pulsed neutron source appears as the most performing. When the reactivity estimate is expressed in dollar unit, the uncertainties obtained with the area-ratio method were less than 1% for any subcritical configuration. The sensitivity to measurement location was about slightly more than 1% and always less than 4%. Finally, it is noteworthy that the source jerk technique using a transient caused by the pulsed neutron source shutdown provides results in good agreement with those obtained from the area-ratio technique. (authors)

  8. Characterization and calibration of Raman based distributed temperature sensing system for 600°C operation

    Science.gov (United States)

    Mandal, Sudeep; Dekate, Sachin; Lee, Boon K.; Guida, Renato; Mondanos, Michael; Yeo, Jackson; Goranson, Marc

    2015-05-01

    Fiber optic distributed temperature sensing based on Raman scattering of light in optical fibers has become a very attractive solution for distributed temperature sensing (DTS) applications. The Raman scattered signal is independent of strain within the fiber, enabling simple packaging solutions for fiber optic temperature sensors while simultaneously improving accuracy and robustness of temperature measurements due to the lack of strain-induced errors in these measurements. Furthermore, the Raman scattered signal increases in magnitude at higher fiber temperatures, resulting in an improved SNR for high temperature measurements. Most Raman DTS instruments and fiber sensors are designed for operation up to approximately 300˚C. We will present our work in demonstrating high temperature calibration of a Raman DTS system using both Ge doped and pure silica core multi-mode optical fiber. We will demonstrate the tradeoffs involved in using each type of fiber for high temperature measurements. In addition, we will describe the challenges of measuring large temperature ranges (0 - 600˚C) with a single DTS interrogator and will demonstrate the need to customize the interrogator electronics and detector response in order to achieve reliable and repeatable high temperature measurements across a wide temperature range.

  9. Towards monolithic scintillator based TOF-PET systems: practical methods for detector calibration and operation

    Science.gov (United States)

    Borghi, Giacomo; Tabacchini, Valerio; Schaart, Dennis R.

    2016-07-01

    Gamma-ray detectors based on thick monolithic scintillator crystals can achieve spatial resolutions  NN) classification method for x,y-position estimation is accelerated with an algorithm that quickly preselects only the most useful reference events, reducing the computation time for position estimation by a factor of ~200 compared to the previously published k-NN 1D method. Also, the procedures for estimating the DOI and time of interaction are revised to enable full detector calibration by means of fan-beam or flood irradiations only. Moreover, a new technique is presented to allow the use of events in which some of the photosensor pixel values and/or timestamps are missing (e.g. due to dead time), so as to further increase system sensitivity. The accelerated methods were tested on a monolithic scintillator detector specifically developed for clinical PET applications, consisting of a 32 mm  ×  32 mm  ×  22 mm LYSO : Ce crystal coupled to a digital photon counter (DPC) array. This resulted in a spatial resolution of 1.7 mm FWHM, an average DOI resolution of 3.7 mm FWHM, and a CRT of 214 ps. Moreover, the possibility of using events missing the information of up to 16 out of 64 photosensor pixels is shown. This results in only a small deterioration of the detector performance.

  10. Calibration of a Gamma Spectrometry System Used for the Determination of Cs-137 in Spanish Soils

    International Nuclear Information System (INIS)

    The document describes the methodology used at CIEMAT in order to determine, by gamma spectrometry, the background levels of the radionuclide Cs-137 in soils of the Spanish peninsular territory. the work is a part of an extensive research project developed jointly by the University of the Basque Country (UPV-EHU) and the CIEMAT, endellite Content and migration of radiocaesium and radiostrontium in Spanish soils, which is funded by the Plan I+D of the Spanish Nuclear Security Council (CSN). The objective of the project is to establish the reference levels of man-made radionuclides in Spanish soils, with respect to which the evaluation of a possible posterior accidental release of radioactive material could be appraised. The activity concentration of the fission products Cs-137 has been determined in 34 soil cores extracted from representative Spanish soils type zones. This publication describes the experimental system employed, its calibration, the particular conditions applied to perform the measurements, as well as the experimental validation of the methodology. The activity profiles and inventories of the radioactive element so obtained are also presented. The estimation of the background Cs-137 reference levels, will provide a basis for later applications as the study of the spatial distribution in the region, the determination of the correlation between the deposited activity and the meteorological conditions, or the calculation of the specific migration parameters of the radioactive elements in Mediterranean conditions. (Author) 15 refs

  11. Design and Instrumentation of a Measurement and Calibration System for an Acoustic Telemetry System

    OpenAIRE

    Zhiqun Deng; Mark Weiland; Thomas Carlson; M. Brad Eppard

    2010-01-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish-friendly” hydroelectric facilities. The objective of this study was ...

  12. Multichannel IR Sensor Calibration Validation Using Planck’s Law for Next Generation Environmental Geostationary Systems

    OpenAIRE

    Pearlman, Aaron; Datla, Raju; Cao, Changyong; Wu, Xiangqian

    2015-01-01

    Multichannel radiometric sensors such as the Advanced Baseline Imager (ABI), which will be onboard the Geostationary Operational Environmental Satellite R-Series, and the Advanced Himawari Imager (AHI), which is currently onboard Himawari 8, provide the possibility to use Planck’s law to validate the absolute calibration of each channel pre-launch as well as on orbit especially in the IR. A technique is developed to use the Planck’s law and evaluate the radiometric calibration of each of the ...

  13. Developing an Efficient Calibration System for Joint Offset of Industrial Robots

    OpenAIRE

    Bingtuan Gao; Yong Liu; Ning Xi; Yantao Shen

    2014-01-01

    Joint offset calibration is one of the most important methods to improve the positioning accuracy for industrial robots. This paper presents an efficient method to calibrate industrial robot joint offset. The proposed method mainly relies on a laser pointer mounted on the robot end-effector and a position sensitive device (PSD) located in the work space arbitrarily. A vision based control was employed to aid the laser beam shooting at the center of PSD surface from several initial robot p...

  14. Calibration method for a in vivo measurement system using mathematical simulation of the radiation source and the detector

    International Nuclear Information System (INIS)

    A Monte Carlo program which uses a voxel phantom has been developed to simulate in vivo measurement systems for calibration purposes. The calibration method presented here employs a mathematical phantom, produced in the form of volume elements (voxels), obtained through Magnetic Resonance Images of the human body. The calibration method uses the Monte Carlo technique to simulate the tissue contamination, the transport of the photons through the tissues and the detection of the radiation. The program simulates the transport and detection of photons between 0.035 and 2 MeV and uses, for the body representation, a voxel phantom with a format of 871 slices each of 277 x 148 picture elements. The Monte Carlo code was applied to the calibration of in vivo systems and to estimate differences in counting efficiencies between homogeneous and non-homogeneous radionuclide distributions in the lung. Calculations show a factor of 20 between deposition of 241 Am at the back compared with the front of the lung. The program was also used to estimate the 137 Cs body burden of an internally contaminated individual, counted with an 8 x 4 Nal (TI) detector and an 241 Am body burden of an internally contaminated individual, who was counted using a planar germanium detector. (author)

  15. Timing calibration of the trigger system for the drift tube detector of the OPERA neutrino oscillation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lenkeit, Jan

    2015-11-15

    The OPERA experiment searches for ν{sub μ} → ν{sub τ} oscillations in an almost pure ν{sub μ} beam. The goal is to observe the oscillations in appearance mode by using a large-scale lead/emulsion target to resolve individual ν{sub τ} interactions. Magnetic spectrometers measure the charge and momentum of beam induced muons leaving the target sections. The Precision Tracker, a drift tube detector consisting of almost 10000 drift tubes, provides the tracking information inside the spectrometers. The coordinate measurement in the drift tubes is derived from a time measurement relative to an external trigger signal. In order to reach the required momentum resolution of less than 25 % for particle momenta up to 25 GeV, the uncertainty on the trigger timing must not exceed a value of 5 ns. In this thesis, a procedure for the timing calibration of the trigger system is presented. A step-by-step calibration of the corresponding signal paths is described. Applying all calibration results, a spatial resolution of 255 μm is achieved for the Precision Tracker, meeting the specified requirements. Furthermore, a method using the calibrated trigger system for performing time of flight measurements with atmospheric muons is developed. The average error on the measured flight times is ±4.5 ns.

  16. Development and validation of a portable gas phase standard generation and calibration system for volatile organic compounds

    Directory of Open Access Journals (Sweden)

    P. Veres

    2010-06-01

    Full Text Available We report on the development of an accurate, portable, dynamic calibration system for volatile organic compounds (VOCs. The Mobile Organic Carbon Calibration System (MOCCS combines the production of gas-phase VOC standards using permeation or diffusion sources with quantitative total organic carbon (TOC conversion on a palladium surface to CO2 in the presence of oxygen, and the subsequent CO2 measurement. MOCCS was validated using three different comparisons: (1 TOC of high accuracy methane standards compared well to expected concentrations (3% relative error, (2 a gas-phase benzene standard was generated using a permeation source and measured by TOC and gas chromatography mass spectrometry (GC-MS with excellent agreement (<4% relative difference, and (3 total carbon measurement of 4 known gas phase mixtures were performed and compared to a calculated carbon content to agreement within the stated uncertainties of the standards. Measurements from laboratory biomass burning experiments of formic acid by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS and formaldehyde by proton transfer reaction-mass spectrometry (PTR-MS, both calibrated using MOCCS, were compared to open path Fourier transform infrared spectroscopy (OP-FTIR to validate the MOCCS calibration and were found to compare well (R2 of 0.91 and 0.99, respectively.

  17. Development and validation of a portable gas phase standard generation and calibration system for volatile organic compounds

    Directory of Open Access Journals (Sweden)

    P. Veres

    2010-01-01

    Full Text Available We report on the development of an accurate, portable, dynamic calibration system for volatile organic compounds (VOCs. The Mobile Organic Carbon Calibration System (MOCCS combines the production of gas-phase VOC standards using permeation or diffusion sources with quantitative total organic carbon (TOC conversion on a palladium surface to CO2 in the presence of oxygen, and the subsequent CO2 measurement. MOCCS was validated using three different comparisons: (1 TOC of high accuracy methane standards compared well to expected concentrations (3% relative error, (2 a gas-phase benzene standard was generated using a permeation source and measured by TOC and gas chromatography mass spectrometry (GC-MS with excellent agreement (<4% relative difference, and (3 total carbon measurement of 4 known gas phase mixtures were performed and compared to a calculated carbon content to agreement within the stated uncertainties of the standards. Measurements from laboratory biomass burning experiments of formic acid by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS and formaldehyde by proton transfer reaction-mass spectrometry (PTR-MS, both calibrated using MOCCS, were compared to open path Fourier transform infrared spectroscopy (OP-FTIR to validate the MOCCS calibration and were found to compare well (R2 of 0.91 and 0.99 respectively.

  18. Automatic In Situ Calibration of a Spinning Beam LiDAR System in Static and Kinematic Modes

    Directory of Open Access Journals (Sweden)

    Ting On Chan

    2015-08-01

    Full Text Available The Velodyne LiDAR series is one of the most popular spinning beam LiDAR systems currently available on the market. In this paper, the temporal stability of the range measurements of the Velodyne HDL-32E LiDAR system is first investigated as motivation for the development of a new automatic calibration method that allows quick and frequent recovery of the inherent time-varying errors. The basic principle of the method is that the LiDAR’s internal systematic error parameters are estimated by constraining point clouds of some known and automatically detected cylindrical features such as lamp poles to fit to the 3D cylinder models. This is analogous to the plumb-line calibration method in which the lens distortion parameters are estimated by constraining the image points of straight lines to fit to the 2D line model. The calibration can be performed at every measurement epoch in both static and kinematic modes. Four real datasets were used to verify the method, two of which were captured in static mode and the other two in kinematic mode. The overall results indicate that up to approximately 72% and 41% accuracy improvement were realized as a result of the calibration for the static and kinematic datasets, respectively.

  19. Presentation, calibration and validation of the low-order, DCESS Earth System Model (Version 1

    Directory of Open Access Journals (Sweden)

    J. O. Pepke Pedersen

    2008-11-01

    Full Text Available A new, low-order Earth System Model is described, calibrated and tested against Earth system data. The model features modules for the atmosphere, ocean, ocean sediment, land biosphere and lithosphere and has been designed to simulate global change on time scales of years to millions of years. The atmosphere module considers radiation balance, meridional transport of heat and water vapor between low-mid latitude and high latitude zones, heat and gas exchange with the ocean and sea ice and snow cover. Gases considered are carbon dioxide and methane for all three carbon isotopes, nitrous oxide and oxygen. The ocean module has 100 m vertical resolution, carbonate chemistry and prescribed circulation and mixing. Ocean biogeochemical tracers are phosphate, dissolved oxygen, dissolved inorganic carbon for all three carbon isotopes and alkalinity. Biogenic production of particulate organic matter in the ocean surface layer depends on phosphate availability but with lower efficiency in the high latitude zone, as determined by model fit to ocean data. The calcite to organic carbon rain ratio depends on surface layer temperature. The semi-analytical, ocean sediment module considers calcium carbonate dissolution and oxic and anoxic organic matter remineralisation. The sediment is composed of calcite, non-calcite mineral and reactive organic matter. Sediment porosity profiles are related to sediment composition and a bioturbated layer of 0.1 m thickness is assumed. A sediment segment is ascribed to each ocean layer and segment area stems from observed ocean depth distributions. Sediment burial is calculated from sedimentation velocities at the base of the bioturbated layer. Bioturbation rates and oxic and anoxic remineralisation rates depend on organic carbon rain rates and dissolved oxygen concentrations. The land biosphere module considers leaves, wood, litter and soil. Net primary production depends on atmospheric carbon dioxide concentration and

  20. Presentation, calibration and validation of the low-order, DCESS Earth System Model

    Directory of Open Access Journals (Sweden)

    J. O. P. Pedersen

    2008-06-01

    Full Text Available A new, low-order Earth system model is described, calibrated and tested against Earth system data. The model features modules for the atmosphere, ocean, ocean sediment, land biosphere and lithosphere and has been designed to simulate global change on time scales of years to millions of years. The atmosphere module considers radiation balance, meridional transport of heat and water vapor between low-mid latitude and high latitude zones, heat and gas exchange with the ocean and sea ice and snow cover. Gases considered are carbon dioxide and methane for all three carbon isotopes, nitrous oxide and oxygen. The ocean module has 100 m vertical resolution, carbonate chemistry and prescribed circulation and mixing. Ocean biogeochemical tracers are phosphate, dissolved oxygen, dissolved inorganic carbon for all three carbon isotopes and alkalinity. Biogenic production of particulate organic matter in the ocean surface layer depends on phosphate availability but with lower efficiency in the high latitude zone, as determined by model fit to ocean data. The calcite to organic carbon rain ratio depends on surface layer temperature. The semi-analytical, ocean sediment module considers calcium carbonate dissolution and oxic and anoxic organic matter remineralisation. The sediment is composed of calcite, non-calcite mineral and reactive organic matter. Sediment porosity profiles are related to sediment composition and a bioturbated layer of 0.1 m thickness is assumed. A sediment segment is ascribed to each ocean layer and segment area stems from observed ocean depth distributions. Sediment burial is calculated from sedimentation velocities at the base of the bioturbated layer. Bioturbation rates and oxic and anoxic remineralisation rates depend on organic carbon rain rates and dissolved oxygen concentrations. The land biosphere module considers leaves, wood, litter and soil. Net primary production depends on atmospheric carbon dioxide concentration and

  1. A quasi-online distributed data processing on WAN: the ATLAS muon calibration system

    CERN Document Server

    De Salvo, A; The ATLAS collaboration

    2013-01-01

    In the Atlas experiment, the calibration of the precision tracking chambers of the muon detector is very demanding, since the rate of muon tracks required to get a complete calibration in homogeneous conditions and to feed prompt reconstruction with fresh constants is very high (several hundreds Hz for 8-10 hours runs). The calculation of calibration constants is highly CPU consuming. In order to fulfill the requirement of completing the cycle and having the final constants available within 24 hours, distributed resources at Tier-2 centers have been allocated. The best place to get muon tracks suitable for detector calibration is the second level trigger, where the pre-selection of data sitting in a limited region by the first level trigger via the Region of Interest mechanism allows selecting all the hits from a single track in a limited region of the detector. Online data extraction allows calibration data collection without performing special runs. Small event pseudo-fragments (about 0.5 kB) built at the m...

  2. A High Precision Approach to Calibrate a Structured Light Vision Sensor in a Robot-Based Three-Dimensional Measurement System.

    Science.gov (United States)

    Wu, Defeng; Chen, Tianfei; Li, Aiguo

    2016-01-01

    A robot-based three-dimensional (3D) measurement system is presented. In the presented system, a structured light vision sensor is mounted on the arm of an industrial robot. Measurement accuracy is one of the most important aspects of any 3D measurement system. To improve the measuring accuracy of the structured light vision sensor, a novel sensor calibration approach is proposed to improve the calibration accuracy. The approach is based on a number of fixed concentric circles manufactured in a calibration target. The concentric circle is employed to determine the real projected centres of the circles. Then, a calibration point generation procedure is used with the help of the calibrated robot. When enough calibration points are ready, the radial alignment constraint (RAC) method is adopted to calibrate the camera model. A multilayer perceptron neural network (MLPNN) is then employed to identify the calibration residuals after the application of the RAC method. Therefore, the hybrid pinhole model and the MLPNN are used to represent the real camera model. Using a standard ball to validate the effectiveness of the presented technique, the experimental results demonstrate that the proposed novel calibration approach can achieve a highly accurate model of the structured light vision sensor. PMID:27589752

  3. A High Precision Approach to Calibrate a Structured Light Vision Sensor in a Robot-Based Three-Dimensional Measurement System

    Directory of Open Access Journals (Sweden)

    Defeng Wu

    2016-08-01

    Full Text Available A robot-based three-dimensional (3D measurement system is presented. In the presented system, a structured light vision sensor is mounted on the arm of an industrial robot. Measurement accuracy is one of the most important aspects of any 3D measurement system. To improve the measuring accuracy of the structured light vision sensor, a novel sensor calibration approach is proposed to improve the calibration accuracy. The approach is based on a number of fixed concentric circles manufactured in a calibration target. The concentric circle is employed to determine the real projected centres of the circles. Then, a calibration point generation procedure is used with the help of the calibrated robot. When enough calibration points are ready, the radial alignment constraint (RAC method is adopted to calibrate the camera model. A multilayer perceptron neural network (MLPNN is then employed to identify the calibration residuals after the application of the RAC method. Therefore, the hybrid pinhole model and the MLPNN are used to represent the real camera model. Using a standard ball to validate the effectiveness of the presented technique, the experimental results demonstrate that the proposed novel calibration approach can achieve a highly accurate model of the structured light vision sensor.

  4. An open-ended waveguide system for SAR system validation or probe calibration for frequencies above 3 GHz

    International Nuclear Information System (INIS)

    Compliance with safety guidelines prescribed in terms of maximum electromagnetic power absorption (specific absorption rate or SAR) for any 1- or 10-g of tissue is required for all newly introduced personal wireless devices such as wireless PCs. The prescribed SAR measuring system is a planar phantom with a relatively thin base of thickness 2.0 mm filled with a lossy fluid to simulate dielectric properties of the tissues. A well-characterized, broadband irradiator is required for SAR system validation or submerged E-field probe calibration for the Wi-Fi frequencies in the 5-6 GHz band. We describe an open-ended waveguide system that may be used for this purpose. Using a fourth-order polynomial least-squares fit to the experimental data gives SAR variations close to the bottom surface of the phantom that are in excellent agreement with those obtained using the finite-difference time-domain (FDTD) numerical method. The experimentally determined peak 1- and 10-g SARs are within 1 to 2% of those obtained using the FDTD both at 5.25 and 5.8 GHz

  5. HJ-1-C卫星SAR系统的内定标%Internal Calibration of HJ-1-C Satellite SAR System

    Institute of Scientific and Technical Information of China (English)

    杨震; 杨汝良

    2014-01-01

    The HJ-1-C satellite is a Synthetic Aperture Radar (SAR) satellite of a small constellation for environmental and disaster monitoring. At present, it is in orbit and working well. The SAR system uses a mesh reflector antenna and centralized power amplifier, and has an internal calibration function in orbit. This study introduces the internal calibration modes and signal paths. The design and realization of the internal calibrator are discussed in detail. Finally, the internal calibration data acquired in orbit are also analyzed.%HJ-1-C 卫星是我国环境与灾害监测小卫星星座中的一颗合成孔径雷达(SAR)卫星,目前已在轨运行。其SAR系统采用网状反射面天线和集中式功率放大器,且具有星上在轨内定标的功能。该文详细介绍了HJ-1-C卫星SAR系统的内定标模式和算法,给出内定标器的设计和实现原理,并对SAR系统在轨工作内定标数据进行分析。

  6. Cross-calibration of far UV spectra of solar system objects and the heliosphere

    CERN Document Server

    Snow, Martin; Bonnet, Roger-Maurice

    2013-01-01

    This book is the result of a working group sponsored by ISSI in Bern, which was initially created to study possible ways to calibrate a Far Ultraviolet (FUV) instrument after launch. In most cases, ultraviolet instruments are well calibrated on the ground, but unfortunately, optics and detectors in the FUV are very sensitive to contaminants and it is very challenging to prevent contamination before and during the test and launch sequences of a space mission. Therefore, ground calibrations need to be confirmed after launch and it is necessary to keep track of the temporal evolution of the sensitivity of the instrument during the mission. The studies presented here cover various fields of FUV spectroscopy with the exclusion of direct solar UV spectroscopy, including a catalog of stellar spectra, data-sets of lunar Irradiance, observations of comets and measurements of the interplanetary background. Detailed modeling of the interplanetary background is presented as well. This work also includes comparisons of ol...

  7. A fully automated system for analysis of pesticides in water: on-line extraction followed by liquid chromatography-tandem photodiode array/postcolumn derivatization/fluorescence detection.

    Science.gov (United States)

    Patsias, J; Papadopoulou-Mourkidou, E

    1999-01-01

    A fully automated system for on-line solid phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) with tandem detection with a photodiode array detector and a fluorescence detector (after postcolumn derivatization) was developed for analysis of many chemical classes of pesticides and their major conversion products in aquatic systems. An automated on-line-SPE system (Prospekt) operated with reversed-phase cartridges (PRP-1) extracts analytes from 100 mL acidified (pH = 3) filtered water sample. On-line HPLC analysis is performed with a 15 cm C18 analytical column eluted with a mobile phase of phosphate (pH = 3)-acetonitrile in 25 min linear gradient mode. Solutes are detected by tandem diode array/derivatization/fluorescence detection. The system is controlled and monitored by a single computer operated with Millenium software. Recoveries of most analytes in samples fortified at 1 microgram/L are > 90%, with relative standard deviation values of < 5%. For a few very polar analytes, mostly N-methylcarbamoyloximes (i.e., aldicarb sulfone, methomyl, and oxamyl), recoveries are < 20%. However, for these compounds, as well as for the rest of the N-methylcarbamates except for aldicarb sulfoxide and butoxycarboxim, the limits of detection (LODs) are 0.005-0.05 microgram/L. LODs for aldicarb sulfoxide and butoxycarboxim are 0.2 and 0.1 microgram, respectively. LODs for the rest of the analytes except 4-nitrophenol, bentazone, captan, decamethrin, and MCPA are 0.05-0.1 microgram/L. LODs for the latter compounds are 0.2-1.0 microgram/L. The system can be operated unattended. PMID:10444834

  8. A simple method for calibration of Lucas scintillation cell counting system for measurement of 226Ra and 222Rn

    Directory of Open Access Journals (Sweden)

    N.K. Sethy

    2014-10-01

    Full Text Available Known quantity of radium from high grade ore solution was chemically separated and carefully kept inside the cavity of a Lucas Cell (LC. The 222Rn gradually builds up and attain secular equilibrium with its parent 226Ra. This gives a steady count after a suitable buildup period (>25 days. This secondary source was used to calibrate the radon counting system. The method is validated in by comparison with identical measurement with AlphaGuard Aquakit. The radon counting system was used to evaluate dissolved radon in ground water sample by gross alpha counting in LC. Radon counting system measures the collected radon after a delay of >180 min by gross alpha counting. Simultaneous measurement also carried out by AlphaGuard Aquakit in identical condition. AlphaGuard measures dissolved radon from water sample by constant aeration in a closed circuit without giving any delay. Both the methods are matching with a correlation coefficient of >0.9. This validates the calibration of Lucas scintillation cell counting system by designed encapsulated source. This study provides an alternative for calibration in absence of costly Radon source available in the market.

  9. The Geometric Calibration of the Planck satellite using Solar System Objects

    CERN Document Server

    Harrison, D L

    2005-01-01

    The geometric calibration of the Planck satellite using the planetary transits is investigated, together with the reconstruction of any offsets from the nominal layout of the focal plane. The methods presented here may be applied to a single focal plane transit of a planet, to find the values of the geometric-calibration parameters at the epoch of the transit or all the transits over the course of the mission. The pointing requirements are easily met, with the pointing reconstruction being dominated by the errors due to the star tracker.

  10. Vicarious Radiometric Calibration of a Multispectral Camera on Board an Unmanned Aerial System

    Directory of Open Access Journals (Sweden)

    Susana Del Pozo

    2014-02-01

    Full Text Available Combinations of unmanned aerial platforms and multispectral sensors are considered low-cost tools for detailed spatial and temporal studies addressing spectral signatures, opening a broad range of applications in remote sensing. Thus, a key step in this process is knowledge of multi-spectral sensor calibration parameters in order to identify the physical variables collected by the sensor. This paper discusses the radiometric calibration process by means of a vicarious method applied to a high-spatial resolution unmanned flight using low-cost artificial and natural covers as control and check surfaces, respectively.

  11. Retrievals of thick cloud optical depth from the Geoscience Laser Altimeter System (GLAS) by calibration of solar background signal

    OpenAIRE

    Yang, Yuekui; Marshak, Alexander; Chiu, J. Christine; Wiscombe, Warren J.; Palm, Stephen P.; Davis, Anthony B.; Spangenberg, Douglas A.; Nguyen, Louis; Spinhirne, James D.; Minnis, Patrick

    2008-01-01

    Laser beams emitted from the Geoscience Laser Altimeter System (GLAS), as well as other spaceborne laser instruments, can only penetrate clouds to a limit of a few optical depths. As a result, only optical depths of thinner clouds (< about 3 for GLAS) are retrieved from the reflected lidar signal. This paper presents a comprehensive study of possible retrievals of optical depth of thick clouds using solar background light and treating GLAS as a solar radiometer. To do so one must first calibr...

  12. Photogrammetric calibration of a C-arm X-ray system as a verification tool for orthopaedic navigation systems

    Science.gov (United States)

    Broers, H.; Hemken, H.; Luhmann, T.; Ritschl, P.

    For the total replacement of the knee joint, the precise reconstruction of the mechanical axis is significantly determined by the alignment of the cutting tool with respect to the rotation centre of the femur head. Operation techniques supported by navigation allow for the precise three-dimensional location of the hip centre by cinematic analysis. Recent results permit the reconstruction of the femur axis to be better than 0.7°. Therefore, conventional verification methods such as the post-operative recording of the complete leg are not suitable due to their limited system accuracy of about 2°. As the femur head cannot be accessed directly during the operation, an X-ray method has been used to verify alignment. The paper presents a method and the results achieved for the calibration of a C-arm system by introducing photogrammetric parameters. Since the method is used during operation, boundary conditions such as minimal invasive surgical intervention and sterility have been considered for practical applications of patients.

  13. Near-infrared calibration systems for precise radial-velocity measurements

    Science.gov (United States)

    Redman, Stephen L.; Kerber, Florian; Nave, Gillian; Mahadevan, Suvrath; Ramsey, Lawrence W.; Smoker, Jonathan; Käufl, Hans-Ulrich; Figueira, P. R. L.

    2012-09-01

    We present work done to prepare two new near-infrared calibration sources for use on high-precision astrophysical spectrographs. Uranium-neon is an atomic calibration source, commercially available as a hollow-cathode lamp, with over 10 000 known emission lines between 0.85 and 4 μm. Four gas cells — containing C2H2, H13CN, 12CO, and 13CO, respectively—are available as National Institute of Standards and Technology (nist) Standard Reference Materials (SRMs), and provide narrow absorption lines between 1.5 and 1.65 μm. These calibration sources may prove useful for wavelength-calibrating the future near-infrared high-precision radial-velocity spectrometers, including the Calar Alto high-Resolution search for M dwarfs with Exo-earths with a Near-infrared Echelle Spectrograph (CARMENES),1 the SpectroPolarimetre InfraROUge (SPIRou)∗, and the Habitable-Zone Planet Finder (HPF).2

  14. Non-Metric CCD Camera Calibration Algorithm in a Digital Photogrammetry System

    Institute of Scientific and Technical Information of China (English)

    YANG Hua-chao; DENG Ka-zhong; ZHANG Shu-bi; GUO Guang-li; ZHOU Ming

    2006-01-01

    Camera calibration is a critical process in photogrammetry and a necessary step to acquire 3D information from a 2D image. In this paper, a flexible approach for CCD camera calibration using 2D direct linear transformation (DLT) and bundle adjustment is proposed. The proposed approach assumes that the camera interior orientation elements are known, and addresses a new closed form solution in planar object space based on homogenous coordinate representation and matrix factorization. Homogeneous coordinate representation offers a direct matrix correspondence between the parameters of the 2D DLT and the collinearity equation. The matrix factorization starts by recovering the elements of the rotation matrix and then solving for the camera position with the collinearity equation. Camera calibration with high precision is addressed by bundle adjustment using the initial values of the camera orientation elements. The results show that the calibration precision of principal point and focal length is about 0.2 and 0.3 pixels respectively, which can meet the requirements of close-range photogrammetry with high accuracy.

  15. Self-Calibration Approach for Mixed Signal Circuits in Systems-on-Chip

    Science.gov (United States)

    Jung, In-Seok

    MOSFET scaling has served industry very well for a few decades by proving improvements in transistor performance, power, and cost. However, they require high test complexity and cost due to several issues such as limited pin count and integration of analog and digital mixed circuits. Therefore, self-calibration is an excellent and promising method to improve yield and to reduce manufacturing cost by simplifying the test complexity, because it is possible to address the process variation effects by means of self-calibration technique. Since the prior published calibration techniques were developed for a specific targeted application, it is not easy to be utilized for other applications. In order to solve the aforementioned issues, in this dissertation, several novel self-calibration design techniques in mixed-signal mode circuits are proposed for an analog to digital converter (ADC) to reduce mismatch error and improve performance. These are essential components in SOCs and the proposed self-calibration approach also compensates the process variations. The proposed novel self-calibration approach targets the successive approximation (SA) ADC. First of all, the offset error of the comparator in the SA-ADC is reduced using the proposed approach by enabling the capacitor array in the input nodes for better matching. In addition, the auxiliary capacitors for each capacitor of DAC in the SA-ADC are controlled by using synthesized digital controller to minimize the mismatch error of the DAC. Since the proposed technique is applied during foreground operation, the power overhead in SA-ADC case is minimal because the calibration circuit is deactivated during normal operation time. Another benefit of the proposed technique is that the offset voltage of the comparator is continuously adjusted for every step to decide one-bit code, because not only the inherit offset voltage of the comparator but also the mismatch of DAC are compensated simultaneously. Synthesized digital

  16. Calibration uncertainty

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Anglov, Thomas

    2002-01-01

    uncertainty was verified from independent measurements of the same sample by demonstrating statistical control of analytical results and the absence of bias. The proposed method takes into account uncertainties of the measurement, as well as of the amount of calibrant. It is applicable to all types......Methods recommended by the International Standardization Organisation and Eurachem are not satisfactory for the correct estimation of calibration uncertainty. A novel approach is introduced and tested on actual calibration data for the determination of Pb by ICP-AES. The improved calibration...

  17. Use of TANDEM methodology for quality control in radiation protection; Aplicacao de metodologia TANDEM para controle de qualidade em radioprotecao

    Energy Technology Data Exchange (ETDEWEB)

    Mello, O.A.; Oliveira, I.R.; Leyton, F.; Nogueira, M.S., E-mail: mnogueira@cdtn.br [Centro de Desenvolvimeto da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Borges, F.L.S., E-mail: flavialuizaborges@yahoo.com.br [Vigilancia Sanitaria de Minas Gerais, Belo Horizonte, MG (Brazil); Joana, G.S., E-mail: georgia.joana@gmail.com [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil)

    2014-07-01

    Recent studies have indicated the increase of the incidence of lens opacities for low radiation doses. Considering epidemiological data, the International Commission on Radiological Protection (ICRP) issued a statement that changed the absorbed dose threshold for the eye lens. The statement also recommends a reduction in the dose limits to the eye lens for occupationally exposed persons; now it is considered to be 20 mSv in a year averaged over five years. For this research two types of thermoluminescent dosimeters TL were used in the construction of the curve tandem. (LiF-100H e LiF-200). For system calibration three monitors were irradiated for each radiation beam. The monitors were irradiated with 4 mGy kerma at 1.5 m from the focal point. The Tandem curve was obtained by the ratio between the values of the energy dependence curves of each dosimeter. Data obtained for the corresponding x-ray beams to radiation reference N60 to N120 are more accurate for determining the energy - steepest part of the curve. The results are shown similar to similar studies and confirm the possibility of using the method for determining the unknown energy radiation fields. (author)

  18. Construction and calibration of the laser alignment system for the CMS tracker

    Energy Technology Data Exchange (ETDEWEB)

    Adolphi, R.

    2006-11-28

    A robust and reliable optical system able to measure and control the large CMS tracker geometry with high accuracy has been developed and validated. The construction and integration of the LAS fulfilling the requirements, as well as its calibration and performance are described in this thesis. The working principle is based on the partial transparency of silicon for light wavelengths in the near infrared region. The absorbed part of the laser beam generates a signal in the corresponding silicon strip module serving to reconstruct its position. The transmitted part reaches the subsequent module layer generating an optical link between the two layers. Investigation of the light generation and distribution led to a definition of the optical components and their optimization for Laser Alignment purposes. Laser diodes have been qualified as light sources and singlemode optical fibres, terminated by special connectors, distribute the light to the CMS tracker detector. The beamsplitting device, a key component of the LAS light distribution inside the CMS tracker, has been studied in detail. The challenge of splitting one collimated beam into two back-to-back beams inside a small available volume has been solved by using the polarization principle. Special test setups were developed to determine the collinearity of the two outgoing beams with a precision better than 50 {mu}rad and it has been shown that their relative orientation remains constant under working conditions. The interface between the tracker and the LAS is given by the silicon sensors which are responsible both for particle detection and for the determination of the position of the laser spot. An anti-reflex-coating has been applied on the backside of all alignment sensors to improve their optical properties without deterioration of their tracking performance. A test setup has been developed to simultaneously study the transmission and reflection properties of the alignment sensors. The working principle of

  19. A quasi-rigorous model based on improved ICP algorithm in the application of auto-calibration of airborne LiDAR system

    Science.gov (United States)

    Li, Lelin; Jiang, San

    2015-12-01

    The purpose of the airborne LiDAR system calibration is to eliminate the influence of system error and improve the precision of the original point cloud data. In certain hypothesis of flight conditions, the directly positioning model for LiDAR can be reduced to a quasi-rigorous model, and the dependence on the original observation data for the system calibration model is reduced too. In view of the shortcoming of human interaction way to establish corresponding relationship between strips, an improved ICP method which considering the object features in point clouds is proposed to get the transform relationship between strips, and the automatic calibration procedures of LiDAR system is established in this paper. Taking with the real LiDAR data in Baotou test field, experiment results show that the proposed system calibration procedures can greatly eliminate the influence of system error.

  20. 压力仪表校验系统设计研究%Pressure gauge calibration system design research

    Institute of Scientific and Technical Information of China (English)

    刘玺

    2012-01-01

    首先介绍了当前行业内压力表校验系统的研究现状,并分析了当前压力仪表检定的发展方向,最后重点对压力仪表校验系统设计,从系统的需求分析出发进行了分析和研究.%This paper firstly introduces the current status of industry within pressure gauge calibration system application, through literature methodology, and analyzed the current pressure gauge verification research situation and developing direction. The research content is discussed on the basis of research of main purpose and topic research. With related system design theory of pressure gauge calibration system design, from the system of needs analysis, this paper summarized the system based on the basic function requirement. Through system design, this paper expounds the basic theory of system design should meet the basic principles.

  1. RSA calibration accuracy of a fluoroscopy-based system using nonorthogonal images for measuring functional kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Kedgley, Angela E.; Jenkyn, Thomas R. [Department of Mechanical and Materials Engineering, Faculty of Engineering, University of Western Ontario, London, Ontario N6A 5B9 (Canada); Wolf Orthopaedic Biomechanics Laboratory, Fowler Kennedy Sport Medicine Clinic, London, Ontario N6A 5B9 (Canada); Department of Mechanical and Materials Engineering, Faculty of Engineering, University of Western Ontario, London, Ontario N6A 5B9 (Canada) and School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London, Ontario N6A 5B9 (Canada)

    2009-07-15

    When performing radiostereometric analysis (RSA) in a clinical setting it may be desirable to orient the two imaging devices nonorthogonally to obtain the best views of an anatomical structure. In this study, a calibration frame was constructed that allowed the relative angles of fiducial and control planes to be adjusted. Precision and accuracy were quantified across multiple trials and orientations. The 90 deg. frame was always of equivalent or greater accuracy than a calibration frame with the fiducial and control planes aligned parallel to the image intensifiers. This study also showed that RSA may be performed with imaging devices at relative angles other than 90 deg. without compromising accuracy. This allows researchers greater freedom in positioning equipment.

  2. Best practices in passive remote sensing VNIR hyperspectral system hardware calibrations

    Science.gov (United States)

    Jablonski, Joseph; Durell, Christopher; Slonecker, Terry; Wong, Kwok; Simon, Blair; Eichelberger, Andrew; Osterberg, Jacob

    2016-01-01

    Hyperspectral imaging (HSI) is an exciting and rapidly expanding area of instruments and technology in passive remote sensing. Due to quickly changing applications, the instruments are evolving to suit new uses and there is a need for consistent definition, testing, characterization and calibration. This paper seeks to outline a broad prescription and recommendations for basic specification, testing and characterization that must be done on Visible Near Infra-Red grating-based sensors in order to provide calibrated absolute output and performance or at least relative performance that will suit the user’s task. The primary goal of this paper is to provide awareness of the issues with performance of this technology and make recommendations towards standards and protocols that could be used for further efforts in emerging procedures for national laboratory and standards groups.

  3. Best practices in passive remote sensing VNIR hyperspectral system hardware calibrations

    Science.gov (United States)

    Jablonski, Joseph; Durell, Christopher; Slonecker, Terrence; Wong, Kwok; Simon, Blair; Eichelberger, Andrew; Osterberg, Jacob

    2016-05-01

    Hyperspectral imaging (HSI) is an exciting and rapidly expanding area of instruments and technology in passive remote sensing. Due to quickly changing applications, the instruments are evolving to suit new uses and there is a need for consistent definition, testing, characterization and calibration. This paper seeks to outline a broad prescription and recommendations for basic specification, testing and characterization that must be done on Visible Near Infra-Red grating-based sensors in order to provide calibrated absolute output and performance or at least relative performance that will suit the user's task. The primary goal of this paper is to provide awareness of the issues with performance of this technology and make recommendations towards standards and protocols that could be used for further efforts in emerging procedures for national laboratory and standards groups.

  4. Measurements of b-hadron lifetimes and the calibration and performance of the LHCb tracking system

    CERN Document Server

    Dupertuis, Frédéric Guillaume

    The LHCb experiment was designed to perform high precision measurements. The LHCb detector has excellent vertexing, momentum measurement and particle identification capabilities, with a detector geometry and trigger strategy specially adapted for the study of rare decays and $CP$ violation of $b$- and $c$-quarks. For accurate measurements, the detector needs to be perfectly calibrated and its performance monitored to achieve the required performance. The LHCb TELL1 boards are responsible for the acquisition and the pre-processing of the raw data. New effects on signals emitted by the front-end chip, the Beetle, of the Inner Tracker (IT) and Tracker Turicensis (TT) due to the different header configurations are discovered. Strategies to correct for these her effects are proposed and are implemented in the firmware of the IT and TT TELL1 boards. In addition, faster algorithms are developed to perform the calibration of the TELL1 boards and software is developed to perform the full calibration and a monitoring ...

  5. QconCAT standard for calibration of ion mobility-mass spectrometry systems.

    Science.gov (United States)

    Chawner, Ross; McCullough, Bryan; Giles, Kevin; Barran, Perdita E; Gaskell, Simon J; Eyers, Claire E

    2012-11-01

    Ion mobility-mass spectrometry (IM-MS) is a useful technique for determining information about analyte ion conformation in addition to mass/charge ratio. The physical principles that govern the mobility of an ion through a gas in the presence of a uniform electric field are well understood, enabling rotationally averaged collision cross sections (Ω) to be directly calculated from measured drift times under well-defined experimental conditions. However, such "first principle" calculations are not straightforward for Traveling Wave (T-Wave) mobility separations due to the range of factors that influence ion motion through the mobility cell. If collision cross section information is required from T-Wave mobility separations, then calibration of the instruments using known standards is essential for each set of experimental conditions. To facilitate such calibration, we have designed and generated an artificial protein based on the QconCAT technology, QCAL-IM, which upon proteolysis can be used as a universal ion mobility calibration standard. This single unique standard enables empirical calculation of peptide ion collision cross sections from the drift time on a T-Wave mobility instrument.

  6. 连轧机组换辊控制系统的研究与应用%Study and Application of Roll Change Control System in Cold Tandem Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    王亮

    2013-01-01

      介绍某1420 mm 五机架冷连轧生产线换辊控制系统的结构与控制方式。%The article describes the structure and control mode of the roll change control system for a 1420 mm five-stand cold tandem rolling mill.

  7. Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers.

    Science.gov (United States)

    Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2016-04-01

    A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV. PMID:26773821

  8. A simple method for calibration of Lucas scintillation cell counting system for measurement of 226Ra and 222Rn

    OpenAIRE

    N.K. Sethy; V.N. Jha; P.M. Ravi; Tripathi, R. M.

    2014-01-01

    Known quantity of radium from high grade ore solution was chemically separated and carefully kept inside the cavity of a Lucas Cell (LC). The 222Rn gradually builds up and attain secular equilibrium with its parent 226Ra. This gives a steady count after a suitable buildup period (>25 days). This secondary source was used to calibrate the radon counting system. The method is validated in by comparison with identical measurement with AlphaGuard Aquakit. The radon counting system was used to eva...

  9. Automatic In Situ Calibration of a Spinning Beam LiDAR System in Static and Kinematic Modes

    OpenAIRE

    Ting On Chan; Lichti, Derek D.

    2015-01-01

    The Velodyne LiDAR series is one of the most popular spinning beam LiDAR systems currently available on the market. In this paper, the temporal stability of the range measurements of the Velodyne HDL-32E LiDAR system is first investigated as motivation for the development of a new automatic calibration method that allows quick and frequent recovery of the inherent time-varying errors. The basic principle of the method is that the LiDAR’s internal systematic error parameters are estimated by c...

  10. Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers.

    Science.gov (United States)

    Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2016-04-01

    A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV.

  11. SPOTS Calibration Example

    Directory of Open Access Journals (Sweden)

    Patterson E.

    2010-06-01

    Full Text Available The results are presented using the procedure outlined by the Standardisation Project for Optical Techniques of Strain measurement to calibrate a digital image correlation system. The process involves comparing the experimental data obtained with the optical measurement system to the theoretical values for a specially designed specimen. The standard states the criteria which must be met in order to achieve successful calibration, in addition to quantifying the measurement uncertainty in the system. The system was evaluated at three different displacement load levels, generating strain ranges from 289 µstrain to 2110 µstrain. At the 289 µstrain range, the calibration uncertainty was found to be 14.1 µstrain, and at the 2110 µstrain range it was found to be 28.9 µstrain. This calibration procedure was performed without painting a speckle pattern on the surface of the metal. Instead, the specimen surface was prepared using different grades of grit paper to produce the desired texture.

  12. Air Data Calibration Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility is for low altitude subsonic altimeter system calibrations of air vehicles. Mission is a direct support of the AFFTC mission. Postflight data merge is...

  13. Design of Combat System Calibration Data Collection and Analysis System%作战系统标校数据采集与分析系统设计

    Institute of Scientific and Technical Information of China (English)

    许晓华; 李鹏

    2015-01-01

    The calibration data of a naval vessel combat system is the reflection of combat system’s function and tech‐nology state of every system equipment .Aiming at the actuality of lack of collection and analysis of the calibration data of a combat system ,a system for calibration data collection and analysis is designed .This paper establishes calibration data entry specification ,designs data analysis applications and analyses processes data .Analysis results show that this system provides a strong support for the management and application of the combat system’s calibration data ,provides references for the rele‐vant decision makers about the equipment maintenance and development .%舰艇作战系统标校数据是作战系统功能、各项系统装备技术状态的反映,针对目前没有对作战系统标校数据进行有效采集与分析的现状,设计了一种标校数据采集与分析系统。文章建立了标校数据录入规范,设计了数据分析功能,对数据进行了分析处理,从而实现了标校数据的有效利用。分析结果证明:该系统对作战系统标校数据的管理和应用提供了支撑,可为装备维护和改进的相关决策人员提供参考。

  14. Four-position heading effect calibration algorithm for rotation inertial navigation system based on fiber optic gyro

    Science.gov (United States)

    Gao, Pengyu; Li, Kui; Wang, Lei; Zhang, Qian

    2016-07-01

    Fiber optic gyros (FOGs) are sensitive to the environment fields where they are mounted, and their drifts are easily affected when surrounding temperature field or magnetic field changes. In FOG strapdown inertial navigation system (INS), gyro drifts caused by environmental fields are stable mostly, thus they could be calibrated and compensated beforehand and would not cause obvious alignment and navigation errors. However, in rotation INS (RINS), although navigation errors caused by the constant components of FOG drifts could be well attenuated, the gyro sensing axes are changing relative to the environmental fields in the RINS, which would lead to periodically changing gyro drift components when inertial measurement unit is pointing to different headings, thus producing serious alignment and navigation errors in FOG RINS. To solve this problem, a four-position heading effect calibration algorithm was proposed, and its effectiveness and validity were verified through a dual-axis FOG RINS by turntable experiments. The experimental results show that the azimuth alignment accuracy of the FOG RINS improves from 0.2 deg to about 0.04 deg, increasing five times approximately, which illustrates that the proposed heading effect calibration algorithm could further improve the navigation performance of FOG RINS significantly.

  15. Four-position heading effect calibration algorithm for rotation inertial navigation system based on fiber optic gyro

    Science.gov (United States)

    Gao, Pengyu; Li, Kui; Wang, Lei; Zhang, Qian

    2016-07-01

    Fiber optic gyros (FOGs) are sensitive to the environment fields where they are mounted, and their drifts are easily affected when surrounding temperature field or magnetic field changes. In FOG strapdown inertial navigation system (INS), gyro drifts caused by environmental fields are stable mostly, thus they could be calibrated and compensated beforehand and would not cause obvious alignment and navigation errors. However, in rotation INS (RINS), although navigation errors caused by the constant components of FOG drifts could be well attenuated, the gyro sensing axes are changing relative to the environmental fields in the RINS, which would lead to periodically changing gyro drift components when inertial measurement unit is pointing to different headings, thus producing serious alignment and navigation errors in FOG RINS. To solve this problem, a four-position heading effect calibration algorithm was proposed, and its effectiveness and validity were verified through a dual-axis FOG RINS by turntable experiments. The experimental results show that the azimuth alignment accuracy of the FOG RINS improves from 0.2 deg to about 0.04 deg, increasing five times approximately, which illustrates that the proposed heading effect calibration algorithm could further improve the navigation performance of FOG RINS significantly.

  16. Bluetooth wireless monitoring, diagnosis and calibration interface for control system of fuel cell bus in Olympic demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Jianfeng; Lin, Xinfan; Xu, Liangfei; Li, Jianqiu; Ouyang, Minggao [Tsinghua University, State Key Laboratory of Automotive Safety and Energy, Beijing100084 (China)

    2009-01-15

    With the worldwide deterioration of the natural environment and the fossil fuel crisis, the possible commercialization of fuel cell vehicles has become a hot topic. In July 2008, Beijing started a clean public transportation plan for the 29th Olympic games. Three fuel cell city buses and 497 other low-emission vehicles are now serving the Olympic core area and Beijing urban areas. The fuel cell buses will operate along a fixed bus line for 1 year as a public demonstration of green energy vehicles. Due to the specialized nature of fuel cell engines and electrified power-train systems, measurement, monitoring and calibration devices are indispensable. Based on the latest Bluetooth wireless technology, a novel Bluetooth universal data interface was developed for the control system of the fuel cell city bus. On this platform, a series of wireless portable control auxiliary systems have been implemented, including wireless calibration, a monitoring system and an in-system programming platform, all of which are ensuring normal operation of the fuel cell buses used in the demonstration. (author)

  17. Bluetooth wireless monitoring, diagnosis and calibration interface for control system of fuel cell bus in Olympic demonstration

    Science.gov (United States)

    Hua, Jianfeng; Lin, Xinfan; Xu, Liangfei; Li, Jianqiu; Ouyang, Minggao

    With the worldwide deterioration of the natural environment and the fossil fuel crisis, the possible commercialization of fuel cell vehicles has become a hot topic. In July 2008, Beijing started a clean public transportation plan for the 29th Olympic games. Three fuel cell city buses and 497 other low-emission vehicles are now serving the Olympic core area and Beijing urban areas. The fuel cell buses will operate along a fixed bus line for 1 year as a public demonstration of green energy vehicles. Due to the specialized nature of fuel cell engines and electrified power-train systems, measurement, monitoring and calibration devices are indispensable. Based on the latest Bluetooth wireless technology, a novel Bluetooth universal data interface was developed for the control system of the fuel cell city bus. On this platform, a series of wireless portable control auxiliary systems have been implemented, including wireless calibration, a monitoring system and an in-system programming platform, all of which are ensuring normal operation of the fuel cell buses used in the demonstration.

  18. ANALYSIS OF EPA (ENVIRONMENTAL PROTECTION AGENCY) PROTOCOL GASES USED FOR CALIBRATION AND AUDITS OF CONTINUOUS EMISSION MONITORING SYSTEMS AND AMBIENT AIR ANALYZERS - RESULTS OF AUDIT 6

    Science.gov (United States)

    A performance audit was conducted on EPA Protocol Gases used for calibration and audits of continuous emission monitoring systems and ambient air analyzers. Fifty gaseous pollutant calibraton standards were purchased from eleven specialty gas producers. These standards contained ...

  19. Calibration of a Plastic Classification System with the CCW Model; Calibracion de un Sistema de Clasification de Plasticos segun el Modelo CCW

    Energy Technology Data Exchange (ETDEWEB)

    Barcala Riveira, J. M.; Fernandez Marron, J. L.; Alberdi Primicia, J.; Navarrete Marin, J. J.; Oller Gonzalez, J. C.

    2003-07-01

    This document describes the calibration of a plastic Classification system with the CCW model (Classification by Quaternions built Wavelet Coefficients). The method is applied to spectra of plastics usually present in domestic wastes. Obtained results are showed. (Author) 16 refs.

  20. An Integrated System for Vadose Zone Monitoring, Model Calibration, Performance Assessment, and Prediction (MCAP) in Hanford's T Tank Farm

    Science.gov (United States)

    Zhang, Z. F.; Keller, J. M.; Myers, D. A.; Sydnor, H. A.

    2006-12-01

    The Hanford Site has 149 underground single-shell tanks that store hazardous radioactive waste. Many of these tanks and their associated infrastructure (e.g., pipelines, diversion boxes) have leaked. Some of the leaked waste is projected to have entered the groundwater. The largest known leak occurred from the T-106 Tank in 1973. Most of the contaminants from that leak still reside within the vadose zone beneath the T Tank Farm. To minimize movement of this residual contaminant plume, an interim infiltration barrier will be constructed on the ground surface. This barrier is expected to prevent infiltrating water from reaching the plume and moving it further towards groundwater. An integrated system will be used for vadose zone moisture monitoring, model calibration, performance assessment, and prediction (MCAP). The system is to be broadly- designed so that the data can be used for multiple purposes. In addition to monitoring soil water movement both under the proposed barrier and adjacent to it, the collected data can also be used to characterize vadose zone hydraulic properties and to calibrate a numerical model. The calibrated model can then be used to assess the performance of the infiltration barrier and to predict water flow and contaminant transport under conditions with and/or without a barrier. A MCAP system is being applied to the Hanford's T Tank Farm. Soil water content is to be monitored using both neutron and capacitance probes; soil water pressure and soil temperature will be monitored with heat dissipation sensors; and water flux will be measured using water fluxmeters. These instruments will be installed in direct push probe holes advanced by a hydraulic hammer unit. Excluding neutron probe measurements, all data collection and data transmittal will be sent to an automated central server. This design allows measurements to be taken continually and reduces the need for personnel to enter the farm thereby increasing worker safety. It is expected that