Calibration of "Babyline" RP instruments

CERN Multimedia

2015-01-01

  If you have old RP instrumentation of the “Babyline” type, as shown in the photo, please contact the Radiation Protection Group (Joffrey Germa, 73171) to have the instrument checked and calibrated. Thank you. Radiation Protection Group

Rotary mode system initial instrument calibration

International Nuclear Information System (INIS)

Johns, B.R.

1994-01-01

The attached report contains the vendor calibration procedures used for the initial instrument calibration of the rotary core sampling equipment. The procedures are from approved vendor information files

Invited Article: Deep Impact instrument calibration.

Science.gov (United States)

Klaasen, Kenneth P; A'Hearn, Michael F; Baca, Michael; Delamere, Alan; Desnoyer, Mark; Farnham, Tony; Groussin, Olivier; Hampton, Donald; Ipatov, Sergei; Li, Jianyang; Lisse, Carey; Mastrodemos, Nickolaos; McLaughlin, Stephanie; Sunshine, Jessica; Thomas, Peter; Wellnitz, Dennis

2008-09-01

Calibration of NASA's Deep Impact spacecraft instruments allows reliable scientific interpretation of the images and spectra returned from comet Tempel 1. Calibrations of the four onboard remote sensing imaging instruments have been performed in the areas of geometric calibration, spatial resolution, spectral resolution, and radiometric response. Error sources such as noise (random, coherent, encoding, data compression), detector readout artifacts, scattered light, and radiation interactions have been quantified. The point spread functions (PSFs) of the medium resolution instrument and its twin impactor targeting sensor are near the theoretical minimum [ approximately 1.7 pixels full width at half maximum (FWHM)]. However, the high resolution instrument camera was found to be out of focus with a PSF FWHM of approximately 9 pixels. The charge coupled device (CCD) read noise is approximately 1 DN. Electrical cross-talk between the CCD detector quadrants is correctable to <2 DN. The IR spectrometer response nonlinearity is correctable to approximately 1%. Spectrometer read noise is approximately 2 DN. The variation in zero-exposure signal level with time and spectrometer temperature is not fully characterized; currently corrections are good to approximately 10 DN at best. Wavelength mapping onto the detector is known within 1 pixel; spectral lines have a FWHM of approximately 2 pixels. About 1% of the IR detector pixels behave badly and remain uncalibrated. The spectrometer exhibits a faint ghost image from reflection off a beamsplitter. Instrument absolute radiometric calibration accuracies were determined generally to <10% using star imaging. Flat-field calibration reduces pixel-to-pixel response differences to approximately 0.5% for the cameras and <2% for the spectrometer. A standard calibration image processing pipeline is used to produce archival image files for analysis by researchers.

Invited Article: Deep Impact instrument calibration

International Nuclear Information System (INIS)

Klaasen, Kenneth P.; Mastrodemos, Nickolaos; A'Hearn, Michael F.; Farnham, Tony; Groussin, Olivier; Ipatov, Sergei; Li Jianyang; McLaughlin, Stephanie; Sunshine, Jessica; Wellnitz, Dennis; Baca, Michael; Delamere, Alan; Desnoyer, Mark; Thomas, Peter; Hampton, Donald; Lisse, Carey

2008-01-01

Calibration of NASA's Deep Impact spacecraft instruments allows reliable scientific interpretation of the images and spectra returned from comet Tempel 1. Calibrations of the four onboard remote sensing imaging instruments have been performed in the areas of geometric calibration, spatial resolution, spectral resolution, and radiometric response. Error sources such as noise (random, coherent, encoding, data compression), detector readout artifacts, scattered light, and radiation interactions have been quantified. The point spread functions (PSFs) of the medium resolution instrument and its twin impactor targeting sensor are near the theoretical minimum [∼1.7 pixels full width at half maximum (FWHM)]. However, the high resolution instrument camera was found to be out of focus with a PSF FWHM of ∼9 pixels. The charge coupled device (CCD) read noise is ∼1 DN. Electrical cross-talk between the CCD detector quadrants is correctable to <2 DN. The IR spectrometer response nonlinearity is correctable to ∼1%. Spectrometer read noise is ∼2 DN. The variation in zero-exposure signal level with time and spectrometer temperature is not fully characterized; currently corrections are good to ∼10 DN at best. Wavelength mapping onto the detector is known within 1 pixel; spectral lines have a FWHM of ∼2 pixels. About 1% of the IR detector pixels behave badly and remain uncalibrated. The spectrometer exhibits a faint ghost image from reflection off a beamsplitter. Instrument absolute radiometric calibration accuracies were determined generally to <10% using star imaging. Flat-field calibration reduces pixel-to-pixel response differences to ∼0.5% for the cameras and <2% for the spectrometer. A standard calibration image processing pipeline is used to produce archival image files for analysis by researchers.

Calibration of dosemeters and survey instruments for photon

International Nuclear Information System (INIS)

Alamares, A.L.; Caseria, E.S.

1995-01-01

The Philippine Nuclear Research Institute (PNRI), the country's regulatory agency, through its Radiation Protection Unit of the Nuclear Regulations Licensing and Safeguard Division provides the calibration services of nuclear instruments used by various institutions. The periodic calibration and standardization of radiation and protection survey instruments are done to insure correct and valid radiation readings. It is also a regulatory requirement for radiation workers to use only operable and precalibrated survey instruments for their work with radioactive materials. The PNRI maintains and operates the Secondary Standard Dosimetry Laboratory (SSDL). It provides the periodic calibration and standardization of radiation monitoring and protection survey instruments, and also the radiological hazard and performance evaluation surveys of radiotherapy facilities and others. For the calibration of survey instruments, the standard sources of Cs-137 and Co-60 are used. The calibration procedures for survey meters and pocket dosimeters are explained. The clients served are shown. The personnel dosimetry using film badges, the application of ICRU operational quantities, and the problems encountered and recommendations are reported. (K.I.)

Novel calibration system with sparse wires for CMB polarization receivers

International Nuclear Information System (INIS)

Tajima, O.; Nguyen, H.; Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A.

2011-01-01

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 (∼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.

Regulatory requirements on the calibration and use of survey instruments

International Nuclear Information System (INIS)

Domondon, D.B.

1989-01-01

Regulatory requirements on the provision, calibration and occasions of use of survey instruments are enumerated for a number of licensed activities. Two methods of calibrating survey instruments are described. Factors that must be taken into consideration in conducting calibrations, contents of calibration reports and of the sticker attached to the instrument which are needed for the correct use of the instrument are discussed. The precautions to be observed in order to insure correct use of survey instruments are described. (Auth.)

Calibration of solar radiation measuring instruments. Final report

Energy Technology Data Exchange (ETDEWEB)

Bahm, R J; Nakos, J C

1979-11-01

A review of solar radiation measurement of instruments and some types of errors is given; and procedures for calibrating solar radiation measuring instruments are detailed. An appendix contains a description of various agencies who perform calibration of solar instruments and a description of the methods they used at the time this report was prepared. (WHK)

Instrument calibration optimization at Bruce Power: ECI loops

International Nuclear Information System (INIS)

Chugh, V.; Angelova, M.; Ghias, S.; Parmar, R.; Wang, V.; Xie, H.; Higgs, J.; Schut, J.; Cruchley, I.

2011-01-01

Most instruments in a nuclear power plant are calibrated at regular intervals to ensure consistency with the assumptions in the plant Technical Specifications and/or Safe Operating Envelope (SOE) compliance limits (e.g., As-Found Tolerance). In the Instrument Uncertainty Calculations (IUC), As-Found Tolerance for instrument drift is estimated based on statistical analysis of As-Found and As-Left calibration data such as that carried out for Bruce NGS by EPRI (Electric Power Research Institute) in 1998. Bruce specific drift values were found to compare favorably with industry benchmarks. Recently a significant amount of work has been done by EPRI and IAEA (International Atomic Energy Agency) on extending calibration intervals of safety related instruments. Reduction in calibration frequency reduces time commitments on the part of Authorized Nuclear Operators and safety system qualified Control Maintenance Technicians, and allows more schedule flexibility. To establish the proof of concept, As-Left/As-Found tolerances and available margins have been evaluated for the Bruce B Emergency Coolant Injection (ECI) system instrument loops to determine whether an extension of the calibration period from one or two year to three years is justifiable on the basis that these loops will still be in compliance with SOE. The analysis showed that 60% of instruments in the ECI system are qualified for calibration interval extension up to three years. Sensitivity assessment of the effect of proposed changes in calibration intervals for 60% of the instruments on the ECI system unavailability has also been performed using the current Bruce Power ECI unavailability model. The results show that, the largest ECI Predicted Future Unavailability (PFU) is 9.2E-4 year/year for in-core LOCA accident. This value is still below the target unavailability of 1.0E-3 year/year. (author)

Instrument calibration optimization at Bruce Power: ECI loops

Energy Technology Data Exchange (ETDEWEB)

Chugh, V.; Angelova, M.; Ghias, S.; Parmar, R.; Wang, V.; Xie, H. [AMEC NSS, Toronto, Ontario (Canada); Higgs, J.; Schut, J.; Cruchley, I. [Bruce Power, Tiverton, Ontario (Canada)

2011-07-01

Most instruments in a nuclear power plant are calibrated at regular intervals to ensure consistency with the assumptions in the plant Technical Specifications and/or Safe Operating Envelope (SOE) compliance limits (e.g., As-Found Tolerance). In the Instrument Uncertainty Calculations (IUC), As-Found Tolerance for instrument drift is estimated based on statistical analysis of As-Found and As-Left calibration data such as that carried out for Bruce NGS by EPRI (Electric Power Research Institute) in 1998. Bruce specific drift values were found to compare favorably with industry benchmarks. Recently a significant amount of work has been done by EPRI and IAEA (International Atomic Energy Agency) on extending calibration intervals of safety related instruments. Reduction in calibration frequency reduces time commitments on the part of Authorized Nuclear Operators and safety system qualified Control Maintenance Technicians, and allows more schedule flexibility. To establish the proof of concept, As-Left/As-Found tolerances and available margins have been evaluated for the Bruce B Emergency Coolant Injection (ECI) system instrument loops to determine whether an extension of the calibration period from one or two year to three years is justifiable on the basis that these loops will still be in compliance with SOE. The analysis showed that 60% of instruments in the ECI system are qualified for calibration interval extension up to three years. Sensitivity assessment of the effect of proposed changes in calibration intervals for 60% of the instruments on the ECI system unavailability has also been performed using the current Bruce Power ECI unavailability model. The results show that, the largest ECI Predicted Future Unavailability (PFU) is 9.2E-4 year/year for in-core LOCA accident. This value is still below the target unavailability of 1.0E-3 year/year. (author)

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.

Contributions of the SDR Task Network tool to Calibration and Validation of the NPOESS Preparatory Project instruments

Science.gov (United States)

Feeley, J.; Zajic, J.; Metcalf, A.; Baucom, T.

2009-12-01

The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) Calibration and Validation (Cal/Val) team is planning post-launch activities to calibrate the NPP sensors and validate Sensor Data Records (SDRs). The IPO has developed a web-based data collection and visualization tool in order to effectively collect, coordinate, and manage the calibration and validation tasks for the OMPS, ATMS, CrIS, and VIIRS instruments. This tool is accessible to the multi-institutional Cal/Val teams consisting of the Prime Contractor and Government Cal/Val leads along with the NASA NPP Mission team, and is used for mission planning and identification/resolution of conflicts between sensor activities. Visualization techniques aid in displaying task dependencies, including prerequisites and exit criteria, allowing for the identification of a critical path. This presentation will highlight how the information is collected, displayed, and used to coordinate the diverse instrument calibration/validation teams.

Onboard calibration and monitoring for the SWIFT instrument

International Nuclear Information System (INIS)

Rahnama, P; McDade, I; Shepherd, G; Gault, W

2012-01-01

The SWIFT (Stratospheric Wind Interferometer for Transport studies) instrument is a proposed space-based field-widened Doppler Michelson interferometer designed to measure stratospheric winds and ozone densities using a passive optical technique called Doppler Michelson imaging interferometry. The onboard calibration and monitoring procedures for the SWIFT instrument are described in this paper. Sample results of the simulations of onboard calibration measurements are presented and discussed. This paper also discusses the results of the derivation of the calibrations and monitoring requirements for the SWIFT instrument. SWIFT's measurement technique and viewing geometry are briefly described. The reference phase calibration and filter monitoring for the SWIFT instrument are two of the main critical design issues. In this paper it is shown that in order to meet SWIFT's science requirements, Michelson interferometer optical path difference monitoring corresponding to a phase calibration accuracy of ∼10 −3 radians, filter passband monitoring corresponding to phase accuracy of ∼5 × 10 −3 radians and a thermal stability of 10 −3 K s −1 are required. (paper)

Radioactive standards and calibration methods for contamination monitoring instruments

Energy Technology Data Exchange (ETDEWEB)

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

1997-06-01

Contamination monitoring in the facilities for handling unsealed radioactive materials is one of the most important procedures for radiation protection as well as radiation dose monitoring. For implementation of the proper contamination monitoring, radiation measuring instruments should not only be suitable to the purpose of monitoring, but also be well calibrated for the objective qualities of measurement. In the calibration of contamination monitoring instruments, quality reference activities need to be used. They are supplied in different such as extended sources, radioactive solutions or radioactive gases. These reference activities must be traceable to the national standards or equivalent standards. On the other hand, the appropriate calibration methods must be applied for each type of contamination monitoring instruments. In this paper, the concepts of calibration for contamination monitoring instruments, reference sources, determination methods of reference quantities and practical calibration methods of contamination monitoring instruments, including the procedures carried out in Japan Atomic Energy Research Institute and some relevant experimental data. (G.K.)

Study of the performance of diagnostic radiology instruments during calibration

International Nuclear Information System (INIS)

Freitas, Rodrigo N. de; Vivolo, Vitor; Potiens, Maria da Penha A.

2008-01-01

Full text: The instruments used in diagnostic radiology measurements represent 8 % of the tested instruments by the calibration laboratory of IPEN annually (approximately 1600 in 2007). Considering that the calibration of this kind of instrument is performed biannually it is possible to conclude that almost 300 instruments are being used to measure the air kerma in diagnostic radiology clinics to determine the in beam values (in front of the patient), attenuated measurements (behind the patient) and scattered radiation. This work presents the results of the calibration of the instruments used in mammography, computed tomography, dental and conventional diagnostic radiology dosimetry, performed during the period of 2005 to 2007. Their performances during the calibrations measurements were evaluated. Although at the calibration laboratory there are three available series of radiation quality to this type of calibration (RQR, N and M, according to standards IEC 61267 and ISO 4037-1.), the applications can be assorted (general radiology, computed tomography, mammography, radiation protection and fluoroscopy). Depending on its design and behaviour , one kind of instrument can be used for one or more type of applications. The instruments normally used for diagnostic radiology measurements are ionization chambers with volumes varying from 3 to 1800 cm 3 , and can be cylindrical, spherical or plane parallel plates kind. They usually are sensitive to photon particles, with energies greater than 15 keV and can be used up to 1200 keV. In this work they were tested in X radiation fields from 25 to 150 kV, in specific qualities depending on the utilization of the instrument. The calibration results of 390 instruments received from 2005 to 2007 were analyzed. About 20 instruments were not able to be calibrated due to bad functioning. The calibration coefficients obtained were between 0.88 and 1.24. The uncertainties were always less than ± 3.6% to instruments used in scattered

A New Automated Instrument Calibration Facility at the Savannah River Site

International Nuclear Information System (INIS)

Polz, E.; Rushton, R.O.; Wilkie, W.H.; Hancock, R.C.

1998-01-01

The Health Physics Instrument Calibration Facility at the Savannah River Site in Aiken, SC was expressly designed and built to calibrate portable radiation survey instruments. The facility incorporates recent advances in automation technology, building layout and construction, and computer software to improve the calibration process. Nine new calibration systems automate instrument calibration and data collection. The building is laid out so that instruments are moved from one area to another in a logical, efficient manner. New software and hardware integrate all functions such as shipping/receiving, work flow, calibration, testing, and report generation. Benefits include a streamlined and integrated program, improved efficiency, reduced errors, and better accuracy

Calibration of radiation protection area monitoring instruments in Sudan

International Nuclear Information System (INIS)

Suliman, I.I.; Youssif, B.E.; Beineen, A.A.; Hassan, M.

2010-01-01

This article presents results of measurements for the calibration of radiation protection area monitoring instruments carried out during the period 2006-2008 at Secondary Standard Dosimetry Laboratory of Sudan. The work performed included quality assurance measurements, measurements for the dosimeter calibrations and uncertainty analysis. Calibrations were performed using 137 Cs gamma ray sources produced by OB 85 and OB 34/1 gamma calibrators producing air kerma rate that ranged from 10 μGy/h to 50 mGy/h. Area monitoring instruments were calibrated in terms of ambient dose equivalent, H*(10) derived using air kerma to ambient dose equivalent conversion coefficients. Results are presented for 78 area monitoring instruments representing most commonly used types in Sudan. Radioactive check source measurements for the reference chamber showed deviation within 1% limit. The accuracy in the beam output measurements was within 5% internationally considered as acceptable. The results highlighted the importance of radiation protection calibrations. Regulations are further need to ensure safety aspect really meet the required international standards.

Instrument performance and simulation verification of the POLAR detector

Science.gov (United States)

Kole, M.; Li, Z. H.; Produit, N.; Tymieniecka, T.; Zhang, J.; Zwolinska, A.; Bao, T. W.; Bernasconi, T.; Cadoux, F.; Feng, M. Z.; Gauvin, N.; Hajdas, W.; Kong, S. W.; Li, H. C.; Li, L.; Liu, X.; Marcinkowski, R.; Orsi, S.; Pohl, M.; Rybka, D.; Sun, J. C.; Song, L. M.; Szabelski, J.; Wang, R. J.; Wang, Y. H.; Wen, X.; Wu, B. B.; Wu, X.; Xiao, H. L.; Xiong, S. L.; Zhang, L.; Zhang, L. Y.; Zhang, S. N.; Zhang, X. F.; Zhang, Y. J.; Zhao, Y.

2017-11-01

POLAR is a new satellite-born detector aiming to measure the polarization of an unprecedented number of Gamma-Ray Bursts in the 50-500 keV energy range. The instrument, launched on-board the Tiangong-2 Chinese Space lab on the 15th of September 2016, is designed to measure the polarization of the hard X-ray flux by measuring the distribution of the azimuthal scattering angles of the incoming photons. A detailed understanding of the polarimeter and specifically of the systematic effects induced by the instrument's non-uniformity are required for this purpose. In order to study the instrument's response to polarization, POLAR underwent a beam test at the European Synchrotron Radiation Facility in France. In this paper both the beam test and the instrument performance will be described. This is followed by an overview of the Monte Carlo simulation tools developed for the instrument. Finally a comparison of the measured and simulated instrument performance will be provided and the instrument response to polarization will be presented.

Evaluation of multivariate calibration models transferred between spectroscopic instruments

DEFF Research Database (Denmark)

Eskildsen, Carl Emil Aae; Hansen, Per W.; Skov, Thomas

2016-01-01

In a setting where multiple spectroscopic instruments are used for the same measurements it may be convenient to develop the calibration model on a single instrument and then transfer this model to the other instruments. In the ideal scenario, all instruments provide the same predictions for the ......In a setting where multiple spectroscopic instruments are used for the same measurements it may be convenient to develop the calibration model on a single instrument and then transfer this model to the other instruments. In the ideal scenario, all instruments provide the same predictions...... for the same samples using the transferred model. However, sometimes the success of a model transfer is evaluated by comparing the transferred model predictions with the reference values. This is not optimal, as uncertainties in the reference method will impact the evaluation. This paper proposes a new method...... for calibration model transfer evaluation. The new method is based on comparing predictions from different instruments, rather than comparing predictions and reference values. A total of 75 flour samples were available for the study. All samples were measured on ten near infrared (NIR) instruments from two...

On-line calibration of process instrumentation channels in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Hashemian, H.M.; Farmer, J.P. [Analysis and Measurement Services Corp., Knoxville, TN (United States)

1995-04-01

An on-line instrumentation monitoring system was developed and validated for use in nuclear power plants. This system continuously monitors the calibration status of instrument channels and determines whether or not they require manual calibrations. This is accomplished by comparing the output of each instrument channel to an estimate of the process it is monitoring. If the deviation of the instrument channel from the process estimate is greater than an allowable limit, then the instrument is said to be {open_quotes}out of calibration{close_quotes} and manual adjustments are made to correct the calibration. The success of the on-line monitoring system depends on the accuracy of the process estimation. The system described in this paper incorporates both simple intercomparison techniques as well as analytical approaches in the form of data-driven empirical modeling to estimate the process. On-line testing of the calibration of process instrumentation channels will reduce the number of manual calibrations currently performed, thereby reducing both costs to utilities and radiation exposure to plant personnel.

Optical modeling and polarization calibration for CMB measurements with ACTPol and Advanced ACTPol

Science.gov (United States)

Koopman, Brian; Austermann, Jason; Cho, Hsiao-Mei; Coughlin, Kevin P.; Duff, Shannon M.; Gallardo, Patricio A.; Hasselfield, Matthew; Henderson, Shawn W.; Ho, Shuay-Pwu Patty; Hubmayr, Johannes; Irwin, Kent D.; Li, Dale; McMahon, Jeff; Nati, Federico; Niemack, Michael D.; Newburgh, Laura; Page, Lyman A.; Salatino, Maria; Schillaci, Alessandro; Schmitt, Benjamin L.; Simon, Sara M.; Vavagiakis, Eve M.; Ward, Jonathan T.; Wollack, Edward J.

2016-07-01

The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive upgrade to the Atacama Cosmology Telescope, located at an elevation of 5190 m on Cerro Toco in Chile. ACTPol uses transition edge sensor bolometers coupled to orthomode transducers to measure both the temperature and polarization of the Cosmic Microwave Background (CMB). Calibration of the detector angles is a critical step in producing polarization maps of the CMB. Polarization angle offsets in the detector calibration can cause leakage in polarization from E to B modes and induce a spurious signal in the EB and TB cross correlations, which eliminates our ability to measure potential cosmological sources of EB and TB signals, such as cosmic birefringence. We calibrate the ACTPol detector angles by ray tracing the designed detector angle through the entire optical chain to determine the projection of each detector angle on the sky. The distribution of calibrated detector polarization angles are consistent with a global offset angle from zero when compared to the EB-nulling offset angle, the angle required to null the EB cross-correlation power spectrum. We present the optical modeling process. The detector angles can be cross checked through observations of known polarized sources, whether this be a galactic source or a laboratory reference standard. To cross check the ACTPol detector angles, we use a thin film polarization grid placed in front of the receiver of the telescope, between the receiver and the secondary reflector. Making use of a rapidly rotating half-wave plate (HWP) mount we spin the polarizing grid at a constant speed, polarizing and rotating the incoming atmospheric signal. The resulting sinusoidal signal is used to determine the detector angles. The optical modeling calibration was shown to be consistent with a global offset angle of zero when compared to EB nulling in the first ACTPol results and will continue to be a part of our calibration implementation. The first

On-ground calibration of the BEPICOLOMBO/SIMBIO-SYS at instrument level

Science.gov (United States)

Rodriguez-Ferreira, J.; Poulet, F.; Eng, P.; Longval, Y.; Dassas, K.; Arondel, A.; Langevin, Y.; Capaccioni, F.; Filacchione, G.; Palumbo, P.; Cremonese, G.; Dami, M.

2012-04-01

The Mercury Planetary Orbiter/BepiColombo carries an integrated suite of instruments, the Spectrometer and Imagers for MPO BepiColombo-Integrated Observatory SYStem (SIMBIO-SYS). SIMBIO-SYS has 3 channels: a stereo imaging system (STC), a high-resolution imager (HRIC) and a visible-near-infrared imaging spectrometer (VIHI). SIMBIO-SYS will scan the surface of Mercury with these three channels and determine the physical, morphological and compositional properties of the entire planet. Before integration on the S/C, an on-ground calibration at the channels and at the instrument levels will be performed so as to describe the instrumental responses as a function of various parameters that might evolve while the instruments will be operating [1]. The Institut d'Astrophysique Spatiale (IAS) is responsible for the on-ground instrument calibration at the instrument level. During the 4 weeks of calibration campaign planned for June 2012, the instrument will be maintained in a mechanical and thermal environment simulating the space conditions. Four Optical stimuli (QTH lamp, Integrating Sphere, BlackBody with variable temperature from 50 to 1200°C and Monochromator), are placed over an optical bench to illuminate the four channels so as to make the radiometric calibration, straylight monitoring, as well as spectral proofing based on laboratory mineral samples. The instrument will be mounted on a hexapod placed inside a thermal vacuum chamber during the calibration campaign. The hexapod will move the channels within the well-characterized incoming beam. We will present the key activities of the preparation of this calibration: the derivation of the instrument radiometric model, the implementation of the optical, mechanical and software interfaces of the calibration assembly, the characterization of the optical bench and the definition of the calibration procedures.

Calibration of the Chemcatcher passive sampler for monitoring selected polar and semi-polar pesticides in surface water

International Nuclear Information System (INIS)

Gunold, Roman; Schaefer, Ralf Bernhard; Paschke, Albrecht; Schueuermann, Gerrit; Liess, Matthias

2008-01-01

Passive sampling is a powerful method for continuous pollution monitoring, but calibration experiments are still needed to generate sampling rates in order to estimate water concentrations for polar compounds. We calibrated the Chemcatcher device with an uncovered SDB-XC Empore disk as receiving phase for 12 polar and semi-polar pesticides in aquatic environments in flow-through tank experiments at two water flow velocities (0.135 m/s and 0.4 m/s). In the 14-day period of exposure the uptake of test substances in the sampler remained linear, and all derived sampling rates R s were in the range of 0.1 to 0.5 L/day. By additionally monitoring the release of two preloaded polar pesticides from the SDB-XC disks over time, very high variation in release kinetics was found, which calls into question the applicability of performance reference compounds. Our study expands the applicability of the Chemcatcher for monitoring trace concentrations of pesticides with frequent occurrence in water. - We calibrated the Chemcatcher passive sampler for current-use polar pesticides in surface waters, allowing its application in future monitoring studies

Calibration of the geometrical characteristics of areal surface topography measuring instruments

International Nuclear Information System (INIS)

Giusca, C L; Leach, R K; Helery, F; Gutauskas, T

2011-01-01

The use of areal surface topography measuring instruments has increased significantly over the past ten years as industry starts to embrace the use of surface structuring to affect the function of a component. This has led to a range of areal surface topography measuring instruments being developed and becoming available commercially. For such instruments to be used as part of quality control during production, it is essential for them to be calibrated according to international standards. The ISO 25178 suite of specification standards on areal surface topography measurement presents a series of tests that can be used to calibrate the metrological characteristics of an areal surface topography measuring instrument. Calibration artefacts and test procedures have been developed that are compliant with ISO 25178. The material measures include crossed gratings, resolution artefacts and pseudorandom surfaces. Traceability is achieved through the NPL Areal Instrument - a primary stylus-based instrument that uses laser interferometers to measure the displacement of the stylus tip. Good practice guides on areal calibration have also been drafted for stylus instruments, coherence scanning interferometers, scanning confocal microscopes and focus variation instruments.

IOT Overview: Calibrations of the VLTI Instruments (MIDI and AMBER)

Science.gov (United States)

Morel, S.; Rantakyrö, F.; Rivinius, T.; Stefl, S.; Hummel, C.; Brillant, S.; Schöller, M.; Percheron, I.; Wittkowski, M.; Richichi, A.; Ballester, P.

We present here a short review of the calibration processes that are currently applied to the instruments AMBER and MIDI of the VLTI (Very Large Telescope Interferometer) at Paranal. We first introduce the general principles to calibrate the raw data (the "visibilities") that have been measured by long-baseline optical interferometry. Then, we focus on the specific case of the scientific operation of the VLTI instruments. We explain the criteria that have been used to select calibrator stars for the observations with the VLTI instruments, as well as the routine internal calibration techniques. Among these techniques, the "P2VM" (Pixel-to-Visibility Matrix) in the case of AMBER is explained. Also, the daily monitoring of AMBER and MIDI, that has recently been implemented, is shortly introduced.

Instrument calibration reduction through on-line monitoring in the USA. Annex IV

International Nuclear Information System (INIS)

Hashemian, H.M.

2008-01-01

Nuclear power plants are required to calibrate important instruments once every fuel cycle. This requirement dates back more than 30 years, when commercial nuclear power plants began to operate. Based on calibration data accumulated over this period, it has been determined that the calibration of some instruments, such as pressure transmitters, do not drift enough to warrant calibration as often as once every fuel cycle. This fact, combined with human resources limitations and reduced maintenance budgets, has provided the motivation for the nuclear industry to develop new technologies for identifying drifting instruments during plant operation. Implementing these technologies allows calibration efforts to be focused on the instruments that have drifted out of tolerance, as opposed to current practice, which calls for calibration verification of almost all instruments every fuel cycle. To date, an array of technologies, referred to collectively as 'on-line calibration monitoring', has been developed to meet this objective. These technologies are based on identifying outlier sensors using techniques that compare a particular sensor's output to a calculated estimate of the actual process the sensor is measuring. If on-line monitoring data are collected during plant startup and/or shutdown periods as well as normal operation, the on-line monitoring approach can help verify the calibration of instruments over their entire operating range. Although on-line calibration monitoring is applicable to most sensors and can cover an entire instrument channel, the main application of this approach in nuclear power plants is currently for pressure transmitters (including level and flow transmitters). (author)

Analysis on detection accuracy of binocular photoelectric instrument optical axis parallelism digital calibration instrument

Science.gov (United States)

Ying, Jia-ju; Yin, Jian-ling; Wu, Dong-sheng; Liu, Jie; Chen, Yu-dan

2017-11-01

Low-light level night vision device and thermal infrared imaging binocular photoelectric instrument are used widely. The maladjustment of binocular instrument ocular axises parallelism will cause the observer the symptom such as dizziness, nausea, when use for a long time. Binocular photoelectric equipment digital calibration instrument is developed for detecting ocular axises parallelism. And the quantitative value of optical axis deviation can be quantitatively measured. As a testing instrument, the precision must be much higher than the standard of test instrument. Analyzes the factors that influence the accuracy of detection. Factors exist in each testing process link which affect the precision of the detecting instrument. They can be divided into two categories, one category is factors which directly affect the position of reticle image, the other category is factors which affect the calculation the center of reticle image. And the Synthesize error is calculated out. And further distribute the errors reasonably to ensure the accuracy of calibration instruments.

Calibration Base Lines for Electronic Distance Measuring Instruments (EDMI)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A calibration base line (CBL) is a precisely measured, straight-line course of approximately 1,400 m used to calibrate Electronic Distance Measuring Instruments...

Planck 2015 results: VIII. High Frequency Instrument data processing: Calibration and maps

DEFF Research Database (Denmark)

Adam, R.; Ade, P. A R; Aghanim, N.

2016-01-01

This paper describes the processing applied to the cleaned, time-ordered information obtained from the Planck High Frequency Instrument (HFI) with the aim of producing photometrically calibrated maps in temperature and (for the first time) in polarization. The data from the entire 2.5-year HFI....... Using a CMB temperature of TCMB = 2.7255 ± 0.0006 K, it permits an independent measurement of the amplitude of the CMB solar dipole (3364.3 ± 1.5 μK), which is approximatively 1σ higher than the WMAP measurement with a direction that is consistent between the two experiments. We describe the pipeline...... used to produce the maps ofintensity and linear polarization from the HFI timelines, and the scheme used to set the zero level of the maps a posteriori. We also summarize the noise characteristics of the HFI maps in the 2015 Planck data release and present some null tests to assess their quality...

Polarization leakage in epoch of reionization windows - II. Primary beam model and direction-dependent calibration

Science.gov (United States)

Asad, K. M. B.; Koopmans, L. V. E.; Jelić, V.; Ghosh, A.; Abdalla, F. B.; Brentjens, M. A.; de Bruyn, A. G.; Ciardi, B.; Gehlot, B. K.; Iliev, I. T.; Mevius, M.; Pandey, V. N.; Yatawatta, S.; Zaroubi, S.

2016-11-01

Leakage of diffuse polarized emission into Stokes I caused by the polarized primary beam of the instrument might mimic the spectral structure of the 21-cm signal coming from the epoch of reionization (EoR) making their separation difficult. Therefore, understanding polarimetric performance of the antenna is crucial for a successful detection of the EoR signal. Here, we have calculated the accuracy of the nominal model beam of Low Frequency ARray (LOFAR) in predicting the leakage from Stokes I to Q, U by comparing them with the corresponding leakage of compact sources actually observed in the 3C 295 field. We have found that the model beam has errors of ≤10 per cent on the predicted levels of leakage of ˜1 per cent within the field of view, I.e. if the leakage is taken out perfectly using this model the leakage will reduce to 10-3 of the Stokes I flux. If similar levels of accuracy can be obtained in removing leakage from Stokes Q, U to I, we can say, based on the results of our previous paper, that the removal of this leakage using this beam model would ensure that the leakage is well below the expected EoR signal in almost the whole instrumental k-space of the cylindrical power spectrum. We have also shown here that direction-dependent calibration can remove instrumentally polarized compact sources, given an unpolarized sky model, very close to the local noise level.

Calibration of the Gamma-RAy Polarimeter Experiment (GRAPE) at a polarized hard X-ray beam

International Nuclear Information System (INIS)

Bloser, P.F.; Legere, J.S.; McConnell, M.L.; Macri, J.R.; Bancroft, C.M.; Connor, T.P.; Ryan, J.M.

2009-01-01

The Gamma-RAy Polarimeter Experiment (GRAPE) is a concept for an astronomical hard X-ray Compton polarimeter operating in the 50-500 keV energy band. The instrument has been optimized for wide-field polarization measurements of transient outbursts from energetic astrophysical objects such as gamma-ray bursts and solar flares. The GRAPE instrument is composed of identical modules, each of which consists of an array of scintillator elements read out by a multi-anode photomultiplier tube (MAPMT). Incident photons Compton scatter in plastic scintillator elements and are subsequently absorbed in inorganic scintillator elements; a net polarization signal is revealed by a characteristic asymmetry in the azimuthal scattering angles. We have constructed a prototype GRAPE module containing a single CsI(Na) calorimeter element, at the center of the MAPMT, surrounded by 60 plastic elements. The prototype has been combined with custom readout electronics and software to create a complete 'engineering model' of the GRAPE instrument. This engineering model has been calibrated using a nearly 100% polarized hard X-ray beam at the Advanced Photon Source at Argonne National Laboratory. We find modulation factors of 0.46±0.06 and 0.48±0.03 at 69.5 and 129.5 keV, respectively, in good agreement with Monte Carlo simulations. In this paper we present details of the beam test, data analysis, and simulations, and discuss the implications of our results for the further development of the GRAPE concept.

The Pelindaba facility for calibrating radiometric field instruments

International Nuclear Information System (INIS)

Corner, B.; Toens, P.D.; Van As, D.; Vleggaar, C.M.; Richards, D.J.

1979-04-01

The tremendous upsurge in uranium exploration activity, experienced in recent years, has made the need for the standardisation and calibration of radiometric field instruments apparent. In order to fulfill this need, construction of a calibration facility at the National Nuclear Research Centre, Pelindaba, was commenced in 1972 and has since been extended according the the requirements of the mining industry. The facility currently comprises 11 surface standard sources suitable for the calibration, in terms of radio-element concentration, of portable scintillometers and spectrometers, and single uranium and thorium model-borehole sources which make possible the accurate calibration of borehole logging instruments both for gross-count and spectrometric surveys. Portable potassium, uranium and thorium sources are also available for the purposes of establishing airborne-spectrometer stripping ratios. The relevant physico-chemical properties of the standards are presented in this report and calibration procedures and data reduction techniques recommended. Examples are given of in situ measurements, both on surface and down-the-hole, which show that the derived calibration constants yield radiometric grades which are, on average, accurate to within 5% of the true radio-element concentrations. A secondary facility comprising single borehole- and surface-uranium sources has also been constructed in Beaufort West in the southern Karoo [af

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.

Calibration methodology for instruments utilized in X radiation beams, diagnostic level

International Nuclear Information System (INIS)

Penha, M. da; Potiens, A.; Caldas, L.V.E.

2004-01-01

Methodologies for the calibration of diagnostic radiology instruments were established at the Calibration Laboratory of IPEN. The methods may be used in the calibration procedures of survey meters used in radiation protection measurements (scattered radiation), instruments used in direct beams (attenuated and non attenuated beams) and quality control instruments. The established qualities are recommended by the international standards IEC 1267 and ISO 4037-3. Two ionization chambers were used as reference systems, one with a volume of 30 cm 3 for radiation protection measurements, and the other with a volume of 1 cm 3 for direct beam measurements. Both are traceable to the German Primary Laboratory of Physikalisch-Technische Bundesanstalt (PTB). In the case of calibration of quality control instruments, a non-invasive method using the measurement of the spectrum endpoint was established with a portable gamma and X-ray Intertechnique spectrometer system. The methods were applied to survey meters (radiation protection measurements), ionization chambers (direct beam measurements) and k Vp meters (invasive and non-invasive instruments). (Author)

Calibration methodology for instruments utilized in X radiation beams, diagnostic level

Energy Technology Data Exchange (ETDEWEB)

Penha, M. da; Potiens, A.; Caldas, L.V.E. [Instituto de Pesquisas Energeticas e Nucleares, Comissao Nacional de Energia Nuclear, Sao Paulo (Brazil)]. E-mail: mppalbu@ipen.br

2004-07-01

Methodologies for the calibration of diagnostic radiology instruments were established at the Calibration Laboratory of IPEN. The methods may be used in the calibration procedures of survey meters used in radiation protection measurements (scattered radiation), instruments used in direct beams (attenuated and non attenuated beams) and quality control instruments. The established qualities are recommended by the international standards IEC 1267 and ISO 4037-3. Two ionization chambers were used as reference systems, one with a volume of 30 cm{sup 3} for radiation protection measurements, and the other with a volume of 1 cm{sup 3} for direct beam measurements. Both are traceable to the German Primary Laboratory of Physikalisch-Technische Bundesanstalt (PTB). In the case of calibration of quality control instruments, a non-invasive method using the measurement of the spectrum endpoint was established with a portable gamma and X-ray Intertechnique spectrometer system. The methods were applied to survey meters (radiation protection measurements), ionization chambers (direct beam measurements) and k Vp meters (invasive and non-invasive instruments). (Author)

Brookhaven National Laboratory meteorological services instrument calibration plan and procedures

Energy Technology Data Exchange (ETDEWEB)

Heiser, John [Brookhaven National Lab. (BNL), Upton, NY (United States)

2013-02-16

This document describes the Meteorological Services (Met Services) Calibration and Maintenance Schedule and Procedures, The purpose is to establish the frequency and mechanism for the calibration and maintenance of the network of meteorological instrumentation operated by Met Services. The goal is to maintain the network in a manner that will result in accurate, precise and reliable readings from the instrumentation.

Polarization information processing and software system design for simultaneously imaging polarimetry

Science.gov (United States)

Wang, Yahui; Liu, Jing; Jin, Weiqi; Wen, Renjie

2015-08-01

Simultaneous imaging polarimetry can realize real-time polarization imaging of the dynamic scene, which has wide application prospect. This paper first briefly illustrates the design of the double separate Wollaston Prism simultaneous imaging polarimetry, and then emphases are put on the polarization information processing methods and software system design for the designed polarimetry. Polarization information processing methods consist of adaptive image segmentation, high-accuracy image registration, instrument matrix calibration. Morphological image processing was used for image segmentation by taking dilation of an image; The accuracy of image registration can reach 0.1 pixel based on the spatial and frequency domain cross-correlation; Instrument matrix calibration adopted four-point calibration method. The software system was implemented under Windows environment based on C++ programming language, which realized synchronous polarization images acquisition and preservation, image processing and polarization information extraction and display. Polarization data obtained with the designed polarimetry shows that: the polarization information processing methods and its software system effectively performs live realize polarization measurement of the four Stokes parameters of a scene. The polarization information processing methods effectively improved the polarization detection accuracy.

Project of an integrated calibration laboratory of instruments at IPEN

International Nuclear Information System (INIS)

Barros, Gustavo Adolfo San Jose

2009-01-01

The Calibration Laboratory of Instruments of Instituto de Pesquisas Energeticas e Nucleares offers calibration services of radiation detectors used in radioprotection, diagnostic radiology and radiotherapy, for IPEN and for external facilities (public and private). One part of its facilities is located in the main building, along with other laboratories and study rooms, and another part in an isolated building called Bunker. For the optimization, modernization and specially the safety, the laboratories in the main building shall be transferred to an isolated place. In this work, a project of an integrated laboratory for calibration of instruments was developed, and it will be an expansion of the current Calibration Laboratory of Instruments of IPEN. Therefore, a series of radiometric monitoring of the chosen localization of the future laboratory was realized, and all staff needs (dimensions and disposition of the study rooms and laboratories) were defined. In this project, the laboratories with X ray equipment, alpha and beta radiation sources were located at an isolated part of the building, and the wall shielding was determined, depending on the use of each laboratory. (author)

Comparison of Two Methodologies for Calibrating Satellite Instruments in the Visible and Near-Infrared

Science.gov (United States)

Barnes, Robert A.; Brown, Steven W.; Lykke, Keith R.; Guenther, Bruce; Butler, James J.; Schwarting, Thomas; Turpie, Kevin; Moyer, David; DeLuccia, Frank; Moeller, Christopher

2015-01-01

Traditionally, satellite instruments that measure Earth-reflected solar radiation in the visible and near infrared wavelength regions have been calibrated for radiance responsivity in a two-step method. In the first step, the relative spectral response (RSR) of the instrument is determined using a nearly monochromatic light source such as a lamp-illuminated monochromator. These sources do not typically fill the field-of-view of the instrument nor act as calibrated sources of light. Consequently, they only provide a relative (not absolute) spectral response for the instrument. In the second step, the instrument views a calibrated source of broadband light, such as a lamp-illuminated integrating sphere. The RSR and the sphere absolute spectral radiance are combined to determine the absolute spectral radiance responsivity (ASR) of the instrument. More recently, a full-aperture absolute calibration approach using widely tunable monochromatic lasers has been developed. Using these sources, the ASR of an instrument can be determined in a single step on a wavelength-by-wavelength basis. From these monochromatic ASRs, the responses of the instrument bands to broadband radiance sources can be calculated directly, eliminating the need for calibrated broadband light sources such as lamp-illuminated integrating spheres. In this work, the traditional broadband source-based calibration of the Suomi National Preparatory Project (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) sensor is compared with the laser-based calibration of the sensor. Finally, the impact of the new full-aperture laser-based calibration approach on the on-orbit performance of the sensor is considered.

Validation of smart sensor technologies for instrument calibration reduction in nuclear power plants

International Nuclear Information System (INIS)

Hashemian, H.M.; Mitchell, D.W.; Petersen, K.M.; Shell, C.S.

1993-01-01

This report presents the preliminary results of a research and development project on the validation of new techniques for on-line testing of calibration drift of process instrumentation channels in nuclear power plants. These techniques generally involve a computer-based data acquisition and data analysis system to trend the output of a large number of instrument channels and identify the channels that have drifted out of tolerance. This helps limit the calibration effort to those channels which need the calibration, as opposed to the current nuclear industry practice of calibrating essentially all the safety-related instrument channels at every refueling outage

Calibration of UV instruments and limitations on accuracy

International Nuclear Information System (INIS)

Clare, J.F.; Hamlin, J.D.

1993-01-01

Instruments measuring UV radiation may be classified as either spectrometers or broadband monitors; whilst the former determine irradiance as a function of wavelength the latter measure a summation of spectral irradiance weighted by some instrument response function which may be designed to approximate a desired action spectrum. For both classes a proper calibration requires the determination of the instrument's absolute spectral responsivity across the relevant wave-band together with an adequate determination of the wavelengths involved. (author). 7 refs

Overview of calibration and validation activities for the EUMETSAT polar system: second generation (EPS-SG) visible/infrared imager (METimage)

Science.gov (United States)

Phillips, P.; Bonsignori, R.; Schlüssel, P.; Schmülling, F.; Spezzi, L.; Watts, P.; Zerfowski, I.

2016-10-01

The EPS-SG Visible/Infrared Imaging (VII) mission is dedicated to supporting the optical imagery user needs for Numerical Weather Prediction (NWP), Nowcasting (NWC) and climate in the timeframe beyond 2020. The VII mission is fulfilled by the METimage instrument, developed by the German Space Agency (DLR) and funded by the German government and EUMETSAT. Following on from an important list of predecessors such as the Advanced Very High Resolution Radiometer (AVHRR) and the Moderate resolution Imaging Spectro-radiometer (MODIS), METimage will fly in the mid-morning orbit of the Joint Polar System, whilst the early-afternoon orbits are served by the JPSS (U.S. Joint Polar Satellite System) Visible Infrared Imager Radiometer Suite (VIIRS). METimage itself is a cross-purpose medium resolution, multi-spectral optical imager, measuring the optical spectrum of radiation emitted and reflected by the Earth from a low-altitude sun synchronous orbit over a minimum swath width of 2700 km. The top of the atmosphere outgoing radiance will be sampled every 500 m (at nadir) with measurements made in 20 spectral channels ranging from 443 nm in the visible up to 13.345 μm in the thermal infrared. The three major objectives of the EPS-SG METimage calibration and validation activities are: • Verification of the instrument performances through continuous in-flight calibration and characterisation, including monitoring of long term stability. • Provision of validated level 1 and level 2 METimage products. • Revision of product processing facilities, i.e. algorithms and auxiliary data sets, to assure that products conform with user requirements, and then, if possible, exceed user expectations. This paper will describe the overall Calibration and Validation (Cal/Val) logic and the methods adopted to ensure that the METimage data products meet performance specifications for the lifetime of the mission. Such methods include inter-comparisons with other missions through simultaneous

Calibration of areal surface topography measuring instruments

Science.gov (United States)

Seewig, J.; Eifler, M.

2017-06-01

The ISO standards which are related to the calibration of areal surface topography measuring instruments are the ISO 25178-6xx series which defines the relevant metrological characteristics for the calibration of different measuring principles and the ISO 25178-7xx series which defines the actual calibration procedures. As the field of areal measurement is however not yet fully standardized, there are still open questions to be addressed which are subject to current research. Based on this, selected research results of the authors in this area are presented. This includes the design and fabrication of areal material measures. For this topic, two examples are presented with the direct laser writing of a stepless material measure for the calibration of the height axis which is based on the Abbott- Curve and the manufacturing of a Siemens star for the determination of the lateral resolution limit. Based on these results, as well a new definition for the resolution criterion, the small scale fidelity, which is still under discussion, is presented. Additionally, a software solution for automated calibration procedures is outlined.

A Bionic Polarization Navigation Sensor and Its Calibration Method.

Science.gov (United States)

Zhao, Huijie; Xu, Wujian

2016-08-03

The polarization patterns of skylight which arise due to the scattering of sunlight in the atmosphere can be used by many insects for deriving compass information. Inspired by insects' polarized light compass, scientists have developed a new kind of navigation method. One of the key techniques in this method is the polarimetric sensor which is used to acquire direction information from skylight. In this paper, a polarization navigation sensor is proposed which imitates the working principles of the polarization vision systems of insects. We introduce the optical design and mathematical model of the sensor. In addition, a calibration method based on variable substitution and non-linear curve fitting is proposed. The results obtained from the outdoor experiments provide support for the feasibility and precision of the sensor. The sensor's signal processing can be well described using our mathematical model. A relatively high degree of accuracy in polarization measurement can be obtained without any error compensation.

Transverse Polarization for Energy Calibration at the Z peak

CERN Document Server

Koratzinos, M

2015-01-01

In this paper we deal with aspects of transverse polarization for the purpose of energy calibration of proposed circular colliders like the FCC-ee and the CEPC. The main issues of such a measurement will be discussed. The possibility of using this method to accurately determine the energy at the WW threshold as well as the Z peak will be addressed. The use of wigglers for reducing long polarization times will be discussed and a possible strategy will be presented for minimising the energy uncertainty error in these large machines.

Polarization Imaging Apparatus with Auto-Calibration

Science.gov (United States)

Zou, Yingyin Kevin (Inventor); Zhao, Hongzhi (Inventor); Chen, Qiushui (Inventor)

2013-01-01

A polarization imaging apparatus measures the Stokes image of a sample. The apparatus consists of an optical lens set, a first variable phase retarder (VPR) with its optical axis aligned 22.5 deg, a second variable phase retarder with its optical axis aligned 45 deg, a linear polarizer, a imaging sensor for sensing the intensity images of the sample, a controller and a computer. Two variable phase retarders were controlled independently by a computer through a controller unit which generates a sequential of voltages to control the phase retardations of the first and second variable phase retarders. A auto-calibration procedure was incorporated into the polarization imaging apparatus to correct the misalignment of first and second VPRs, as well as the half-wave voltage of the VPRs. A set of four intensity images, I(sub 0), I(sub 1), I(sub 2) and I(sub 3) of the sample were captured by imaging sensor when the phase retardations of VPRs were set at (0,0), (pi,0), (pi,pi) and (pi/2,pi), respectively. Then four Stokes components of a Stokes image, S(sub 0), S(sub 1), S(sub 2) and S(sub 3) were calculated using the four intensity images.

Software System for the Calibration of X-Ray Measuring Instruments

International Nuclear Information System (INIS)

Gaytan-Gallardo, E.; Tovar-Munoz, V. M.; Cruz-Estrada, P.; Vergara-Martinez, F. J.; Rivero-Gutierrez, T.

2006-01-01

A software system that facilities the calibration of X-ray measuring instruments used in medical applications is presented. The Secondary Standard Dosimetry Laboratory (SSDL) of the Nuclear Research National Institute in Mexico (ININ in Spanish), supports activities concerning with ionizing radiations in medical area. One of these activities is the calibration of X-ray measuring instruments, in terms of air kerma or exposure by substitution method in an X-ray beam at a point where the rate has been determined by means of a standard ionization chamber. To automatize this process, a software system has been developed, the calibration system is composed by an X-ray unit, a Dynalizer IIIU X-ray meter by RADCAL, a commercial data acquisition card, the software system and the units to be tested and calibrated. A quality control plan has been applied in the development of the software system, ensuring that quality assurance procedures and standards are being followed

Reflectance of Mercury's Polar Regions: Calibration and Implications for Mercury's Volatiles

Science.gov (United States)

Neumann, G. A.; Sun, X.; Cao, A.; Deutsch, A. N.; Head, J. W.

2018-05-01

Calibration of laser altimeter reflectances under widely varying conditions is supported by laboratory data from an engineering simulator to address the distribution of volatile deposits in Mercury's polar cold traps.

Design Through Integration of On-Board Calibration Device with Imaging Spectroscopy Instruments

Science.gov (United States)

Stange, Michael

2012-01-01

The main purpose of the Airborne Visible and Infrared Imaging Spectroscopy (AVIRIS) project is to "identify, measure, and monitor constituents of the Earth's surface and atmosphere based on molecular absorption and particle scattering signatures." The project designs, builds, and tests various imaging spectroscopy instruments that use On-Board Calibration devices (OBC) to check the accuracy of the data collected by the spectrometers. The imaging instrument records the spectral signatures of light collected during flight. To verify the data is correct, the OBC shines light which is collected by the imaging spectrometer and compared against previous calibration data to track spectral response changes in the instrument. The spectral data has the calibration applied to it based on the readings from the OBC data in order to ensure accuracy.

Instrument evaluation, calibration, and installation for the heater experiments at Stripa

International Nuclear Information System (INIS)

Schrauf, T.; Pratt, H.; Simonson, E.; Hustrulid, W.; Nelson, P.; DuBois, A.; Binnall, E.; Haught, R.

1979-12-01

Borehole instrumentation for the measurement of temperature, displacement, and stress was evaluated, modified, calibrated, and installed in an underground site at Stripa, Sweden where experiments are currently underway to investigate the suitability of granite as a storage medium for nuclear waste. Three arrays of borehole instrumentation measure the thermomechanical effects caused by electrical heaters which simulate the thermal output of canisters of radioactive waste. Because most rock mechanics investigations are carried out at modest temperatures, a sustained operating temperature as high as 200 0 C was an unusual and most important criterion governing the instrumentation program. Extensive laboratory experiments were conducted to determine the effect of high temperature on instrument behavior and also to develop calibration and data-reduction procedures. The rod extensometers were tested for anchor creep, the selection of a suitable high-temperature pressurizing fluid, and the thermal stability of the grout. Four temperature corrections are incorporated into the data reduction of the USBM borehole deformation measurement: the bridge voltage offset correction, the change in calibration factor induced by temperature, and the thermal expansion of the gage and of the rock. The vibrating wire gages were calibrated in the laboratory by loading gages installed in a granite block at pressures up to 13 MPa and at temperatures ranging from 20 0 to 200 0 C. Both the slope and offset of the response equation are corrected for temperature effects. Most thermocouples were calibrated in an oven at the field site. Thermocouples were emplaced with individual gages and into holes backfilled with sand or grout

Next Generation Polar Seismic Instrumentation Challenges

Science.gov (United States)

Parker, T.; Beaudoin, B. C.; Gridley, J.; Anderson, K. R.

2011-12-01

Polar region logistics are the limiting factor for deploying deep field seismic arrays. The IRIS PASSCAL Instrument Center, in collaboration with UNAVCO, designed and deployed several systems that address some of the logistical constraints of polar deployments. However, continued logistics' pressures coupled with increasingly ambitious science projects require further reducing the logistics required for deploying both summer and over winter stations. Our focus is to reduce station power requirements and bulk, thereby minimizing the time and effort required to deploy these arrays. We will reduce the weight of the battery bank by incorporating the most applicable new high energy-density battery technology. Using these batteries will require a completely new power management system along with an appropriate smart enclosure. The other aspect will be to integrate the digitizing system with the sensor. Both of these technologies should reduce the install time and shipping volume plus weight while reducing some instrument costs. We will also continue work on an effective Iridium telemetry solution for automated data return. The costs and limitations of polar deep-field science easily justifies a specialized development effort but pays off doubly in that we will continue to leverage the advancements in reduced logistics and increased performance for the benefit of low-latitude seismic research.

Automation is an Effective Way to Improve Quality of Verification (Calibration) of Measuring Instruments

Science.gov (United States)

Golobokov, M.; Danilevich, S.

2018-04-01

In order to assess calibration reliability and automate such assessment, procedures for data collection and simulation study of thermal imager calibration procedure have been elaborated. The existing calibration techniques do not always provide high reliability. A new method for analyzing the existing calibration techniques and developing new efficient ones has been suggested and tested. A type of software has been studied that allows generating instrument calibration reports automatically, monitoring their proper configuration, processing measurement results and assessing instrument validity. The use of such software allows reducing man-hours spent on finalization of calibration data 2 to 5 times and eliminating a whole set of typical operator errors.

Calibration of NRSF2 Instrument at HFIR

International Nuclear Information System (INIS)

Tang, Fei; Hubbard, Camden R.

2006-01-01

The Neutron Residual Stress Mapping Facility (NRSF2) at HB-2B is a new generation-diffraction instrument, adding many new Second Generation features, such as larger beam tube, large sample XYZ goniometer, and KAPPA orienter for a broad range of materials behavior studies. One key feature is the NRSF2 monochromator, which is a double focusing, double crystal monochromator system consisting of two sets of stacked Si crystal wafers. One set of wafers has Si[400] plane normal to the surface while the other set of wafers has the Si[500] normal to the surface. The monochromator crystal diffracts at a fixed diffraction angle of 88 o selecting a neutron wavelength determined by the monochromator d hkl -spacing. This 'Missouri' monochromator system has two independent monochromators, which enable diffraction from the following set of six diffraction planes: Si(511), Si(422), Si(331)AF (Anti-Fankuchen geometry), Si(400), Si(311), and Si(220). These diffraction planes can provide 6 different neutron wavelengths: approximately 1.45, 1.54, 1.73, 1.89 (angstrom), 2.27, and 2.66 also incorporate seven position sensitive detectors located in a detector shield box. To use this advanced instrument for scientific and engineering measurements, careful calibration needs to be performed to accurately calibrate the seven position sensitive detectors, neutron wavelength, and 2θ 0 . Just as in the X-ray diffraction technique, neutron diffraction directly measures the diffraction angle (2θ) or diffraction peak position, then based on Bragg's law and a strain free lattice spacing, the strain can be calculated. Therefore anything that can affect the diffracting angle measurement can influence the accuracy of the strain measurements. The sources of difficulties in achieving accurate neutron diffraction peak positions can be classified into three categories. (1) Instrument - These difficulties come from alignment of the monochromator, alignment of the incident and detector slits, leveling of

Proceedings of the workshop on radiation survey instruments and calibrations

International Nuclear Information System (INIS)

Selby, J.M.; Swinth, K.L.; Vallario, E.J.; Murphy, B.L.

1985-11-01

The workshop was held to discuss two topics: first, a performance standard for radiation survey instruments and the potential for a testing program based on that standard; and second, a system of secondary standards laboratories to provide instrument calibrations and related services. Separate abstracts have been prepared for the individual presentations

Influence of Loading Rate on the Calibration of Instrumented Charpy Strikers

Energy Technology Data Exchange (ETDEWEB)

Lucon, E.; Scibetta, M.; McColskey, D.; McCowan, C.

2009-01-15

One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. The conventional approach for establishing an analytical relationship between strain gage output and force applied to the transducer is the static calibration, which is preferably performed with the striker installed in the pendulum assembly. However, the response of an instrumented striker under static force application may sometimes differ significantly from its dynamic performance during an actual Charpy test. This is typically reflected in a large difference between absorbed energy returned by the pendulum encoder (KV) and calculated under the instrumented force/displacement test record (Wt). Such difference can be either minimized by optimizing the striker design or analytically removed by adjusting forces and displacements until KV = Wt (the so-called 'Dynamic Force Adjustment'). This study investigates the influence of increasing force application rates on the force/voltage characteristics of two instrumented strikers, one at NIST in Boulder, CO and one at SCK-CEN in Mol, Belgium.

Compact blackbody calibration sources for in-flight calibration of spaceborne infrared instruments

Science.gov (United States)

Scheiding, S.; Driescher, H.; Walter, I.; Hanbuch, K.; Paul, M.; Hartmann, M.; Scheiding, M.

2017-11-01

High-emissivity blackbodies are mandatory as calibration sources in infrared radiometers. Besides the requirements on the high spectral emissivity and low reflectance, constraints regarding energy consumption, installation space and mass must be considered during instrument design. Cavity radiators provide an outstanding spectral emissivity to the price of installation space and mass of the calibration source. Surface radiation sources are mainly limited by the spectral emissivity of the functional coating and the homogeneity of the temperature distribution. The effective emissivity of a "black" surface can be optimized, by structuring the substrate with the aim to enlarge the ratio of the surface to its projection. Based on the experiences of the Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) calibration source MBB3, the results of the surface structuring on the effective emissivity are described analytically and compared to the experimental performance. Different geometries are analyzed and the production methods are discussed. The high-emissivity temperature calibration source features values of 0.99 for wavelength from 5 μm to 10 μm and emissivity larger than 0.95 for the spectral range from 10 μm to 40 μm.

Technological considerations in emergency instrumentation preparedness. Phase II-D. Evaluation testing and calibration methodology for emergency radiological instrumentation

International Nuclear Information System (INIS)

Bramson, P.E.; Andersen, B.V.; Fleming, D.M.; Kathren, R.L.; Mulhern, O.R.; Newton, C.E.; Oscarson, E.E.; Selby, J.M.

1976-09-01

In response to recommendations from the Advisory Committee on Reactor Safeguards, the Division of Operational Safety, U.S. ERDA has contracted with Battelle, Pacific Northwest Laboratories to survey the adequacy of existing instrumentation at nuclear fuel cycle facilities to meet emergency requirements and to develop technical criteria for instrumentation systems to be used in assessment of environmental conditions following plant emergencies. This report, the fifth in a series, provides: (1) calibration methods to assure the quality of radiological measurements and (2) testing procedures for determining whether an emergency radiological instrument meets the performance specifications. Three previous reports in this series identified the emergency instrumentation needs for power reactors, mixed oxide fuel plants, and fuel reprocessing facilities. Each of these three reports contains a Section VI, which sets forth applicable radiological instrument performance criteria and calibration requirements. Testing and calibration procedures in this report have been formatted in two parts: IV and V, each divided into three subsections: (1) Power Reactors, (2) Mixed Oxide Fuel Plants, and (3) Fuel Reprocessing Facilities. The three performance criteria subsections directly coincide with the performance criteria sections of the previous reports. These performance criteria sections have been reproduced in this report as Part III with references of ''required action'' added

The pre-flight calibration setup of the instrument SIMBIO-SYS onboard the mission BepiColombo

Science.gov (United States)

Poulet, F.; Rodriguez-Ferreira, J.; Arondel, A.; Dassas, K.; Eng, P.; Lami, P.; Langevin, Y.; Longval, Y.; Pradel, P.; Dami, M.

2015-11-01

BepiColombo, an European Space Agency (ESA) mission being conducted in cooperation with the Japan space agency, will explore Mercury with a set of eleven instruments onboard the spacecraft Mercury Planetary Orbiter (MPO). Among them, SIMBIO-SYS (Spectrometers and Imagers for MPO BepiColombo Integrated Observatory SYStem) is a complex instrument that will provide images and spectra in the 400-2000 nm wavelength range of the entire surface of Mercury. Pre-flight calibration of the SYMBIO-SYS instrument is mandatory for reliable scientific interpretation of images and spectra returned from the planet Mercury. This paper presents the calibration device designed and implemented for the specific requirements of this instrument. It mainly consists of a thermal vacuum chamber simulating the space environment, an optical bench collecting calibration sources and optical elements that simulate the conditions of Mercury observations, mechanical interfaces used for positioning the three channels inside the vacuum chamber, thermal interfaces to explore the operating temperatures, computer interfaces that allow to communicate with both the instrument and the calibration elements and synchronize the calibrations sequences with the status of the calibration device. As the major goal is the characterization of the radiometric performances of the three channels of SIMBIO-SYS, radiometric performances of the test setup evaluated by simulations and measurements are emphasized.

On-line testing of calibration of process instrumentation channels in nuclear power plants. Phase 2, Final report

International Nuclear Information System (INIS)

Hashemian, H.M.

1995-11-01

The nuclear industry is interested in automating the calibration of process instrumentation channels; this report provides key results of one of the sponsored projects to determine the validity of automated calibrations. Conclusion is that the normal outputs of instrument channels in nuclear plants can be monitored over a fuel cycle while the plant is operating to determine calibration drift in the field sensors and associated signal conversion and signal conditioning equipment. The procedure for on-line calibration tests involving calculating the deviation of each instrument channel from the best estimate of the process parameter that the instrument is measuring. Methods were evaluated for determining the best estimate. Deviation of each signal from the best estimate is updated frequently while the plant is operating and plotted vs time for entire fuel cycle, thereby providing time history plots that can reveal channel drift and other anomalies. Any instrument channel that exceeds allowable drift or channel accuracy band is then scheduled for calibration during a refueling outage or sooner. This provides calibration test results at the process operating point, one of the most critical points of the channel operation. This should suffice for most narrow-range instruments, although the calibration of some instruments can be verified at other points throughout their range. It should be pointed out that the calibration of some process signals such as the high pressure coolant injection flow in BWRs, which are normally off- scale during plant operation, can not be tested on-line

40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Gas meter or flow instrumentation... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement. (a) Sampling for particulate emissions requires the use of gas meters or flow instrumentation to...

Standard practice of calibration of force-measuring instruments for verifying the force indication of testing machines

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 The purpose of this practice is to specify procedures for the calibration of force-measuring instruments. Procedures are included for the following types of instruments: 1.1.1 Elastic force-measuring instruments, and 1.1.2 Force-multiplying systems, such as balances and small platform scales. Note 1Verification by deadweight loading is also an acceptable method of verifying the force indication of a testing machine. Tolerances for weights for this purpose are given in Practices E 4; methods for calibration of the weights are given in NIST Technical Note 577, Methods of Calibrating Weights for Piston Gages. 1.2 The values stated in SI units are to be regarded as the standard. Other metric and inch-pound values are regarded as equivalent when required. 1.3 This practice is intended for the calibration of static force measuring instruments. It is not applicable for dynamic or high speed force calibrations, nor can the results of calibrations performed in accordance with this practice be assumed valid for...

Instrument Performance and Simulation Verification of the POLAR Detector

OpenAIRE

Kole, M.; Li, Z. H.; Produit, N.; Tymieniecka, T.; Zhang, J.; Zwolinska, A.; Bao, T. W.; Bernasconi, T.; Cadoux, F.; Feng, M. Z.; Gauvin, N.; Hajdas, W.; Kong, S. W.; Li, H. C.; Li, L.

2017-01-01

POLAR is a new satellite-born detector aiming to measure the polarization of an unprecedented number of Gamma-Ray Bursts in the 50-500 keV energy range. The instrument, launched on-board the Tiangong-2 Chinese Space lab on the 15th of September 2016, is designed to measure the polarization of the hard X-ray flux by measuring the distribution of the azimuthal scattering angles of the incoming photons. A detailed understanding of the polarimeter and specifically of the systematic effects induce...

Detailed Calibration of SphinX instrument at the Palermo XACT facility of INAF-OAPA

Science.gov (United States)

Szymon, Gburek; Collura, Alfonso; Barbera, Marco; Reale, Fabio; Sylwester, Janusz; Kowalinski, Miroslaw; Bakala, Jaroslaw; Kordylewski, Zbigniew; Plocieniak, Stefan; Podgorski, Piotr; Trzebinski, Witold; Varisco, Salvatore

The Solar photometer in X-rays (SphinX) experiment is scheduled for launch late summer 2008 on-board the Russian CORONAS-Photon satellite. SphinX will use three silicon PIN diode detectors with selected effective areas in order to record solar spectra in the X-ray energy range 0.3-15 keV with unprecedented temporal and medium energy resolution. High sensitivity and large dynamic range of the SphinX instrument will give for the first time possibility of observing solar soft X-ray variability from the weakest levels, ten times below present thresholds, to the largest X20+ flares. We present the results of the ground X-ray calibrations of the SphinX instrument performed at the X-ray Astronomy Calibration and Testing (XACT) facility of INAF-OAPA. The calibrations were essential for determination of SphinX detector energy resolution and efficiency. We describe the ground tests instrumental set-up, adopted measurement techniques and present results of the calibration data analysis.

Suborbital Reusable Launch Vehicles as an Opportunity to Consolidate and Calibrate Ground Based and Satellite Instruments

Science.gov (United States)

Papadopoulos, K.

2014-12-01

XCOR Aerospace, a commercial space company, is planning to provide frequent, low cost access to near-Earth space on the Lynx suborbital Reusable Launch Vehicle (sRLV). Measurements in the external vacuum environment can be made and can launch from most runways on a limited lead time. Lynx can operate as a platform to perform suborbital in situ measurements and remote sensing to supplement models and simulations with new data points. These measurements can serve as a quantitative link to existing instruments and be used as a basis to calibrate detectors on spacecraft. Easier access to suborbital data can improve the longevity and cohesiveness of spacecraft and ground-based resources. A study of how these measurements can be made on Lynx sRLV will be presented. At the boundary between terrestrial and space weather, measurements from instruments on Lynx can help develop algorithms to optimize the consolidation of ground and satellite based data as well as assimilate global models with new data points. For example, current tides and the equatorial electrojet, essential to understanding the Thermosphere-Ionosphere system, can be measured in situ frequently and on short notice. Furthermore, a negative-ion spectrometer and a Faraday cup, can take measurements of the D-region ion composition. A differential GPS receiver can infer the spatial gradient of ionospheric electron density. Instruments and optics on spacecraft degrade over time, leading to calibration drift. Lynx can be a cost effective platform for deploying a reference instrument to calibrate satellites with a frequent and fast turnaround and a successful return of the instrument. A calibrated reference instrument on Lynx can make collocated observations as another instrument and corrections are made for the latter, thus ensuring data consistency and mission longevity. Aboard a sRLV, atmospheric conditions that distort remotely sensed data (ground and spacecraft based) can be measured in situ. Moreover, an

Inter-laboratory project q calibration of SANS instruments using silver behenate

International Nuclear Information System (INIS)

Ikram, Abarrul; Gunawan; Edy Giri, Putra; Suzuki, Jun-ichi; Knott, Robert

2000-01-01

The inter-laboratory project for q-calibration of SANS (small angle neutron scattering) using silver behenate was carried out among Indonesia National Nuclear Energy Agency (BATAN), Japan Atomic Energy Research Institute (JAERI) and Australian Nuclear Science and Technology Organization (ANSTO). The standard sample of silver behenate, [CH 3 (CH 2 ) 20 COOAg](AgBE), has been assessed as an international standard for the calibration of both x-ray and neutron scattering instruments. The results indicate excellent agreement for q calibration obtained among the three laboratories, BATAN, JAERI and ANSTO. (Y. Kazumata)

Design and use of concrete pads for the calibration of radiometric survey instrumentation

International Nuclear Information System (INIS)

Loevborg, L.

1984-10-01

A gamma-ray spectrometer for use in geological exploration possesses four stripping ratios and three window sensitivities which must be determined to make the instrumentation applicable for field assay or airborne measurement of potassium, uranium, and thorium contents in the ground. Survey organizations in many parts of the world perform the instrument calibration using large pads of concrete which simulate a plane ground of known radioelement concentration. Calibration and monitoring trials with twelve facilities in ten countries prove that moisture absorption, radon exhalation, and particle-size effects can offset a radiometric grade assigned to concrete whose aggregate contains an embedded radioactive mineral. These and other calibration problems are discussed from a combined theoretical and practical viewpoint

The polarized neutron small-angle scattering instrument at BENSC Berlin

International Nuclear Information System (INIS)

Keller, T.; Krist, T.; Danzig, A.; Keiderling, U.; Mezei, F.; Wiedenmann, A.

2000-01-01

A polarized neutron beam has been installed at the small-angle neutron-scattering instrument V4 at BENSC Berlin. The main component of this new option is a 1.8 m long cavity transmission polarizer. The advantages of this device compared to the conventional bender polarizers are: (i) high transmission (35% of unpolarized beam at λ=6 A); (ii) the polarization is better than 93% in the wavelength band 4 A 3 O 4 particles embedded in a glass matrix) are presented and compared to a measurement with unpolarized neutrons

New Submersed Chamber for Calibration of Relative Humidity Instruments at HMI/FSB-LPM

Science.gov (United States)

Sestan, D.; Zvizdic, D.; Sariri, K.

2018-02-01

This paper gives a detailed description of a new chamber designed for calibration of relative humidity (RH) instruments at Laboratory for Process Measurement (HMI/FSB-LPM). To the present time, the calibrations of RH instruments at the HMI/FSB-LPM were done by comparison method using a climatic chamber of large volume and calibrated dew point hygrometer with an additional thermometer. Since 2010, HMI/FSB-LPM in cooperation with Centre for Metrology and Accreditation in Finland (MIKES) developed the two primary dew point generators which cover the dew point temperature range between - 70 {°}C and 60 {°}C. In order to utilize these facilities for calibrations of the RH instruments, the new chamber was designed, manufactured and installed in the existing system, aiming to extend its range and reduce the related calibration uncertainties. The chamber construction allows its use in a thermostatic bath of larger volume as well as in the climatic chambers. In the scope of this paper, performances of the new chamber were tested while it was submersed in a thermostated bath. The chamber can simultaneously accommodate up to three RH sensors. In order to keep the design of the chamber simple, only cylindrical RH sensors detachable from display units can be calibrated. Possible optimizations are also discussed, and improvements in the design proposed. By using the new chamber, HMI/FSB-LPM reduced the expanded calibration uncertainties (level of confidence 95 %, coverage factor k=2) from 0.6 %rh to 0.25 %rh at 30 %rh (23 {°}C), and from 0.8 %rh to 0.53 %rh at 70 %rh (23 {°}C).

Calibration system with cryogenically-cooled loads for cosmic microwave background polarization detectors.

Science.gov (United States)

Hasegawa, M; Tajima, O; Chinone, Y; Hazumi, M; Ishidoshiro, K; Nagai, M

2011-05-01

We present a novel system to calibrate millimeter-wave polarimeters for cosmic microwave background (CMB) polarization measurements. This technique is an extension of the conventional metal mirror rotation approach, however, it employs cryogenically-cooled blackbody absorbers. The primary advantage of this system is that it can generate a slightly polarized signal (∼100 mK) in the laboratory; this is at a similar level to that measured by ground-based CMB polarization experiments observing a ∼10 K sky. It is important to reproduce the observing condition in the laboratory for reliable characterization of polarimeters before deployment. In this paper, we present the design and principle of the system and demonstrate its use with a coherent-type polarimeter used for an actual CMB polarization experiment. This technique can also be applied to incoherent-type polarimeters and it is very promising for the next-generation CMB polarization experiments.

Building 772 - CERN’s new calibration facility for radiation protection instruments is ready to go

CERN Document Server

2014-01-01

Building 772 is becoming the new home of CERN’s calibration facility for radiation protection instrumentation. The new laboratory in Prévessin will be a state-of-the-art calibration facility and the first of its kind in both France and Switzerland, offering a wide range of possibilities with respect to radiation fields and instrumentation.   New four-axis calibration bench for radiation protection instruments.   Civil engineering work started in November 2013 in Prévessin and Building 772 is now finished and ready for inauguration. CERN’s calibration facility was previously located in Building 172 in Meyrin. Although still very accurate, the technology used was becoming obsolete and needed replacement. “Having considered different options, the decision was taken to build a new facility fully designed and conceived to meet all international safety and technical requirements of such a laboratory,” says Pie...

OSIRIS (Observing System Including PolaRisation in the Solar Infrared Spectrum) instrument: a multi-directional, polarized radiometer in the visible and shortwave infrared, airborne prototype of 3MI / EPS-SG Eumetsat - ESA mission

Science.gov (United States)

Matar, C.; Auriol, F.; Nicolas, J. M.; Parol, F.; Riedi, J.; Djellali, M. S.; Cornet, C.; Waquet, F.; Catalfamo, M.; Delegove, C.; Loisil, R.

2017-12-01

OSIRIS instrument largely inherits from the POLDER concept developed and operated between 1991 (first airborne prototype) and 2013 (end of the POLDER-3/PARASOL space-borne mission). It consists in two optical systems, one covering the visible to near infrared range (440, 490, 670, 763, 765, 870, 910 and 940 nm) and a second one for the shortwave infrared (940, 1020, 1240, 1360, 1620 and 2200 nm). Each optical system is composed of a wide field-of-view optics (114° and 105° respectively) associated to two rotating wheels with interferential filters (spectral) and analyzers filters (polarization) respectively, and a 2D array of detectors. For each channel, radiance is measured once without analyzer, followed by sequential measurements with the three analyzers shifted by an angle of 60° to reconstruct the total and polarized radiances. The complete acquisition sequence for all spectral channels last a couple of seconds according to the chosen measurement protocol. Thanks to the large field of view of the optics, any target is seen under several viewing angles during the aircraft motion. In a first step we will present the new ground characterization of the instrument based on laboratory measurements (linearity, flat-field, absolute calibration, induced polarization, polarizers efficiency and position), the radiometric model and the Radiometric Inverted Model (RIM) used to develop the Level 1 processing chain that is used to produce level 1 products (normalized radiances, polarized or not, with viewing geometries) from the instrument generated level 0 files (Digital Counts) and attitude information from inertial system. The stray light issues will be specifically discussed. In a second step we will present in-flight radiometric and geometric methods applied to OSIRIS data in order to control and validate ground-based calibrated products: molecular scattering method and sun-glint cross-band method for radiometric calibration, glories, rainbows and sun-glint targets

Current activities and plans for polarized neutron instruments of the JSNS/J-PARC project

International Nuclear Information System (INIS)

Furusaka, M.

2005-01-01

Neutron polarization is one of the key technologies for the next generation megawatt-class pulsed spallation neutron sources, such as SNS in the US and the JSNS in Japan. To polarize or analyze neutron spin, several techniques are under development in Japan: a small d-spacing magnetic multilayer mirror, spin exchange type He-3 filter and a dynamical proton polarizer. Several application techniques related to polarized neutrons are also under development, such as, a microwave-induced optical nuclear polarization technique, which allows us to polarize protons in naphtalene doped with pentacene at 77 K; neutron focusing-SANS instrument utilizing a focusing magnet; a Drabkin spin-filter instrument that has two filters in series for neutron-pulse shaping

Probing of Hermean Exosphere by ultraviolet spectroscopy: Instrument presentation, calibration philosophy and first lights results

Science.gov (United States)

Mariscal, J. F.; Rouanet, N.; Maria, J. L.; Quémerais, E.; Mine, P. O.; Zuppella, P.; Suman, M.; Nicolosi, P.; Pelizzo, M. G.; Yoshikawa, I.; Yoshioka, K.; Murakami, G.

2017-11-01

PHEBUS (Probing of Hermean Exosphere by Ultraviolet Spectroscopy) is a double spectrometer for the Extreme Ultraviolet range (55-155 nm) and the Far Ultraviolet range (145-315 nm) dedicated to the characterization of Mercury's exosphere composition and dynamics, and surface-exosphere connections. PHEBUS is part of the ESA BepiColombo cornerstone mission payload devoted to the study of Mercury. The BepiColombo mission consists of two spacecrafts: the Mercury Magnetospheric Orbiter (MMO) and the Mercury Planetary Orbiter (MPO) on which PHEBUS will be mounted. PHEBUS is a French-led instrument implemented in a cooperative scheme involving Japan (detectors), Russia (scanner) and Italy (ground calibration). Before launch, PHEBUS team want to perform a full absolute calibration on ground, in addition to calibrations which will be made in-flight, in order to know the instrument's response as precisely as possible. Instrument overview and calibration philosophy are introduced along with the first lights results observed by a first prototype.

Conception of the Instrument Calibration Laboratory of Ionizing Radiation Measurement (LACIMRI) of CTMSP - Sao Paulo, SP

International Nuclear Information System (INIS)

Silva, Raimundo Dias da; Kibrit, Eduardo

2009-01-01

The present work describes the phases of implantation of calibration laboratory of ionizing radiation measurement instruments at the CTMSP, Sao Paulo, in a priory approved by CNEN, Brazil. That laboratory will allow and enhance the present metrological capacity for the attendance to the growing demand for calibration services of the instruments

A novel angle computation and calibration algorithm of bio-inspired sky-light polarization navigation sensor.

Science.gov (United States)

Xian, Zhiwen; Hu, Xiaoping; Lian, Junxiang; Zhang, Lilian; Cao, Juliang; Wang, Yujie; Ma, Tao

2014-09-15

Navigation plays a vital role in our daily life. As traditional and commonly used navigation technologies, Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS) can provide accurate location information, but suffer from the accumulative error of inertial sensors and cannot be used in a satellite denied environment. The remarkable navigation ability of animals shows that the pattern of the polarization sky can be used for navigation. A bio-inspired POLarization Navigation Sensor (POLNS) is constructed to detect the polarization of skylight. Contrary to the previous approach, we utilize all the outputs of POLNS to compute input polarization angle, based on Least Squares, which provides optimal angle estimation. In addition, a new sensor calibration algorithm is presented, in which the installation angle errors and sensor biases are taken into consideration. Derivation and implementation of our calibration algorithm are discussed in detail. To evaluate the performance of our algorithms, simulation and real data test are done to compare our algorithms with several exiting algorithms. Comparison results indicate that our algorithms are superior to the others and are more feasible and effective in practice.

POLAR on board of the Tiangong 2 Chinese space station: measuring the polarization of hard X-rays photons, in particular the polarization of prompt photons from gamma ray bursts.

Science.gov (United States)

Produit, Nicolas

2012-07-01

POLAR is an homogeneous wide field Compton polarimeter using plastic scintillators and multichannel photomultipliers. The goal of this polarimeter is to measure with controlled systematics the polarization of hard X-ray emitted by unpredictable transient sources The instrument energy range sensitivity is optimized for the detection of the prompt emission of Gamma-Ray Bursts (GRB). Monte-Carlo studies and calibration data collected in polarized photon beams predict that POLAR will be able to measure the polarization degree of 10 GRB per year with a combined systematics and statistical accuracy of better then 10%. POLAR will be mounted outside of the Tiangong 2 Chinese space station that will be launched in space in 2014.

Atacama Cosmology Telescope: Polarization calibration analysis for CMB measurements with ACTPol and Advanced ACTPol

Science.gov (United States)

Koopman, Brian; ACTPol Collaboration

2015-04-01

The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive upgrade for the Atacama Cosmology Telescope, located at an elevation of 5190 m on Cerro Toco in Chile. Achieving first light in 2013, ACTPol is entering its third observation season. Advanced ACTPol is a next generation upgrade for ACTPol, with additional frequencies, polarization modulation, and new detector arrays, that will begin in 2016. I will first present an overview of the two projects and then focus on describing the methods used for polarization angle calibration of the ACTPol detectors. These methods utilize polarization ray tracing in the optical design software CODEV together with detector positions determined from planet observations and represent a critical input for mapping the polarization of the CMB.

Design and Calibration of a Novel Bio-Inspired Pixelated Polarized Light Compass

Directory of Open Access Journals (Sweden)

Guoliang Han

2017-11-01

Full Text Available Animals, such as Savannah sparrows and North American monarch butterflies, are able to obtain compass information from skylight polarization patterns to help them navigate effectively and robustly. Inspired by excellent navigation ability of animals, this paper proposes a novel image-based polarized light compass, which has the advantages of having a small size and being light weight. Firstly, the polarized light compass, which is composed of a Charge Coupled Device (CCD camera, a pixelated polarizer array and a wide-angle lens, is introduced. Secondly, the measurement method of a skylight polarization pattern and the orientation method based on a single scattering Rayleigh model are presented. Thirdly, the error model of the sensor, mainly including the response error of CCD pixels and the installation error of the pixelated polarizer, is established. A calibration method based on iterative least squares estimation is proposed. In the outdoor environment, the skylight polarization pattern can be measured in real time by our sensor. The orientation accuracy of the sensor increases with the decrease of the solar elevation angle, and the standard deviation of orientation error is 0 . 15 ∘ at sunset. Results of outdoor experiments show that the proposed polarization navigation sensor can be used for outdoor autonomous navigation.

Radiation Budget Instrument (RBI) for JPSS-2

Science.gov (United States)

Georgieva, Elena; Priestley, Kory; Dunn, Barry; Cageao, Richard; Barki, Anum; Osmundsen, Jim; Turczynski, Craig; Abedin, Nurul

2015-01-01

Radiation Budget Instrument (RBI) will be one of five instruments flying aboard the JPSS-2 spacecraft, a polar-orbiting sun-synchronous satellite in Low Earth Orbit. RBI is a passive remote sensing instrument that will follow the successful legacy of the Clouds and Earth's Radiant Energy System (CERES) instruments to make measurement of Earth's short and longwave radiation budget. The goal of RBI is to provide an independent measurement of the broadband reflected solar radiance and Earth's emitted thermal radiance by using three spectral bands (Shortwave, Longwave, and Total) that will have the same overlapped point spread function (PSF) footprint on Earth. To ensure precise NIST-traceable calibration in space the RBI sensor is designed to use a visible calibration target (VCT), a solar calibration target (SCT), and an infrared calibration target (ICT) containing phase change cells (PCC) to enable on-board temperature calibration. The VCT is a thermally controlled integrating sphere with space grade Spectralon covering the inner surface. Two sides of the sphere will have fiber-coupled laser diodes in the UV to IR wavelength region. An electrical substitution radiometer on the integrating sphere will monitor the long term stability of the sources and the possible degradation of the Spectralon in space. In addition the radiometric calibration operations will use the Spectralon diffusers of the SCT to provide accurate measurements of Solar degradation. All those stable on-orbit references will ensure that calibration stability is maintained over the RBI sensor lifetime. For the preflight calibration the RBI will view five calibration sources - two integrating spheres and three CrIS (Cross-track Infrared Sounder ) -like blackbodies whose outputs will be validated with NIST calibration approach. Thermopile are the selected detectors for the RBI. The sensor has a requirement to perform lunar calibration in addition to solar calibration in space in a way similar to CERES

Fluorescence of the gamma, epsilon, and delta systems of nitric oxide - Polarization and use of calculated intensities for spectrometer calibration.

Science.gov (United States)

Poland, H. M.; Broida, H. P.

1971-01-01

Results of a study in which fluorescence of the gamma system of nitric oxide was obtained by excitation from both the 2144 A line of ionized cadmium and a continuum source. Individual rotational lines of the 2144 A excited fluorescence spectrum were found to be partially polarized and to have polarizations of differ ing sign. Measured relative vibrational band intensities from line and continuum excitation were compared to calculated Franck-Condon factors. Those Franck-Condon factors based on a single potential for the two spin states of the X super pi state agreed better with measured values than those based on separate potentials for the two spin states. Calculated intensities of the v prime = 3 progression were used to calibrate the instrument response in the wavelength region from 2000 to 2500 A and were checked with measured intensities of the v prime = 0.1, and 2 progressions. Fluorescence of the epsilon and delta bands obtained with continuum lamp excitation also were compared to calculated intensities.

The 1997 HST Calibration Workshop with a New Generation of Instruments

Science.gov (United States)

Casertano, S. (Editor); Jedrzejewski, R. (Editor); Keyes, T. (Editor); Stevens, M. (Editor)

1997-01-01

The Second Servicing mission in early 1997 has brought major changes to the Hubble Space Telescope (HST). Two of the original instruments, Faint Object Spectrograph (FOS) and Goddard High Resolution Spectrograph (GHRS), were taken out, and replaced by completely new instruments, the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera Multi-Object Spectrograph (NICMOS). Two new types of detectors were installed, and for the first time, HST gained infrared capabilities. A new Fine Guidance Sensor (FGS) was installed, with an alignment mechanism that could improve substantially both guiding and astrometric capabilities. With all these changes come new challenges. The characterization of the new instruments has required a major effort, both by their respective Investigation Definition Teams and at the Space Telescope Science Institute. All necessary final calibrations for the retired spectrographs needed to be carried out, and their properties definitively characterized. At the same time, work has continued to improve our understanding of the instruments that have remained on board. The results of these activities were discussed in the 1997 HST (Hubble Space Telescope) Calibration Workshop. The main focus of the Workshop was to provide users with the tools and the understanding they need to use HST's instruments and archival data to the best of their possibilities. This book contains the written record of the Workshop. As such, it should provide a valuable tool to all interested in using existing HST data or in proposing for new observations.

Calibration method based on direct radioactivity measurement for radioactive gas monitoring instruments

International Nuclear Information System (INIS)

Yoshida, Makoto; Ohi, Yoshihiro; Chida, Tohru; Wu, Youyang.

1993-01-01

A calibration method for radioactive gas monitoring instruments was studied. In the method, gaseous radioactivity standards were provided on the basis of the direct radioactivity measurement by the diffusion-in long proportional counter method (DLPC method). The radioactivity concentration of the gas mixture through a monitoring instrument was determined by sampling the known volume of the gas mixture into the proportional counter used for the DLPC method. Since oxygen in the gas mixture decreased the counting efficiency in a proportional counter, the influence on calibration was experimentally estimated. It was not serious and able to be easily corrected. By the present method, the relation between radioactivity concentration and ionization current was determined for a gas-flow ionization chamber with 1.5 l effective volume. It showed good agreement with the results in other works. (author)

New instrument calibration facility for the DOE Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Wilkie, W.H.; Polz, E.J. [Westinghouse Savannah River Company, Aiken, SC (United States)

1993-12-31

A new laboratory facility is being designed, constructed, and equipped at the Savannah River Site (SRS) as a fiscal year 1992 line item project. This facility will provide space and equipment for test, evaluation, repair, maintenance, and calibration of radiation monitoring instrumentation. The project will replace an obsolete facility and will allow implementation of program upgrades necessary to meet ANSI N323 requirements and National Voluntary Laboratory Accreditation Program (NVLAP) criteria for accreditation of federally owned secondary calibration laboratories. An outline of the project is presented including description, scope, cost, management organization, chronology, and current status. Selected design criteria and their impacts on the project are discussed. The upgraded SRS calibration program is described, and important features of the new facility and equipment that will accommodate this program are listed. The floor plan for the facility is shown, and equipment summaries and functional descriptions for each area are provided.

New instrument calibration facility for the DOE Savannah River Site

International Nuclear Information System (INIS)

Wilkie, W.H.; Polz, E.J.

1993-01-01

A new laboratory facility is being designed, constructed, and equipped at the Savannah River Site (SRS) as a fiscal year 1992 line item project. This facility will provide space and equipment for test, evaluation, repair, maintenance, and calibration of radiation monitoring instrumentation. The project will replace an obsolete facility and will allow implementation of program upgrades necessary to meet ANSI N323 requirements and National Voluntary Laboratory Accreditation Program (NVLAP) criteria for accreditation of federally owned secondary calibration laboratories. An outline of the project is presented including description, scope, cost, management organization, chronology, and current status. Selected design criteria and their impacts on the project are discussed. The upgraded SRS calibration program is described, and important features of the new facility and equipment that will accommodate this program are listed. The floor plan for the facility is shown, and equipment summaries and functional descriptions for each area are provided

Developing Spent Fuel Assembly for Advanced NDA Instrument Calibration - NGSI Spent Fuel Project

Energy Technology Data Exchange (ETDEWEB)

Hu, Jianwei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gauld, Ian C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Banfield, James [GE Hitachi Nuclear Energy, Wilmington, NC (United States); Skutnik, Steven [Univ. of Tennessee, Knoxville, TN (United States)

2014-02-01

This report summarizes the work by Oak Ridge National Laboratory to investigate the application of modeling and simulation to support the performance assessment and calibration of the advanced nondestructive assay (NDA) instruments developed under the Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) Project. Advanced NDA instrument calibration will likely require reference spent fuel assemblies with well-characterized nuclide compositions that can serve as working standards. Because no reference spent fuel standard currently exists, and the practical ability to obtain direct measurement of nuclide compositions using destructive assay (DA) measurements of an entire fuel assembly is prohibitive in the near term due to the complexity and cost of spent fuel experiments, modeling and simulation will be required to construct such reference fuel assemblies. These calculations will be used to support instrument field tests at the Swedish Interim Storage Facility (Clab) for Spent Nuclear Fuel.

Instrumentation calibration

International Nuclear Information System (INIS)

Mack, D.A.

1976-08-01

Procedures for the calibration of different types of laboratory equipment are described. Provisions for maintaining the integrity of reference and working standards traceable back to a national standard are discussed. Methods of validation and certification methods are included. An appendix lists available publications and services of national standardizing agencies

Optical Comb from a Whispering Gallery Mode Resonator for Spectroscopy and Astronomy Instruments Calibration

Science.gov (United States)

Strekalov, Dmitry V.; Yu, Nam; Thompson, Robert J.

2012-01-01

The most accurate astronomical data is available from space-based observations that are not impeded by the Earth's atmosphere. Such measurements may require spectral samples taken as long as decades apart, with the 1 cm/s velocity precision integrated over a broad wavelength range. This raises the requirements specifically for instruments used in astrophysics research missions -- their stringent wavelength resolution and accuracy must be maintained over years and possibly decades. Therefore, a stable and broadband optical calibration technique compatible with spaceflights becomes essential. The space-based spectroscopic instruments need to be calibrated in situ, which puts forth specific requirements to the calibration sources, mainly concerned with their mass, power consumption, and reliability. A high-precision, high-resolution reference wavelength comb source for astronomical and astrophysics spectroscopic observations has been developed that is deployable in space. The optical comb will be used for wavelength calibrations of spectrographs and will enable Doppler measurements to better than 10 cm/s precision, one hundred times better than the current state-of-the- art.

A method for automating calibration and records management for instrumentation and dosimetry

Energy Technology Data Exchange (ETDEWEB)

O`Brien, J.M. Jr.; Rushton, R.O.; Burns, R.E. Jr. [Atlan-Tech, Inc., Roswell, GA (United States)

1993-12-31

Current industry requirements are becoming more stringent on quality assurance records and documentation for calibration of instruments and dosimetry. A novel method is presented here that will allow a progressive automation scheme to be used in pursuit of that goal. This concept is based on computer-controlled irradiators that can act as stand-alone devices or be interfaced to other components via a computer local area network. In this way, complete systems can be built with modules to create a records management system to meet the needs of small laboratories or large multi-building calibration groups. Different database engines or formats can be used simply by replacing a module. Modules for temperature and pressure monitoring or shipping and receiving can be added, as well as equipment modules for direct IEEE-488 interface to electrometers and other instrumentation.

A method for automating calibration and records management for instrumentation and dosimetry

International Nuclear Information System (INIS)

O'Brien, J.M. Jr.; Rushton, R.O.; Burns, R.E. Jr.

1993-01-01

Current industry requirements are becoming more stringent on quality assurance records and documentation for calibration of instruments and dosimetry. A novel method is presented here that will allow a progressive automation scheme to be used in pursuit of that goal. This concept is based on computer-controlled irradiators that can act as stand-alone devices or be interfaced to other components via a computer local area network. In this way, complete systems can be built with modules to create a records management system to meet the needs of small laboratories or large multi-building calibration groups. Different database engines or formats can be used simply by replacing a module. Modules for temperature and pressure monitoring or shipping and receiving can be added, as well as equipment modules for direct IEEE-488 interface to electrometers and other instrumentation

Using MCNP for in-core instrument calibration in CANDU

Energy Technology Data Exchange (ETDEWEB)

Taylor, D.C. [Point Lepreau Generating Station, NB Power, Lepreau, New Brunswick (Canada); Anghel, V.N.P.; Sur, B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2002-07-01

The calibration of in-core instruments is important for safe and economical CANDU operation. However, in-core detectors are not normally suited to bench calibration procedures. This paper describes the use and validation of detailed neutron transport calculations for the purpose of calibrating the response of in-core neutron flux detectors. The Monte-Carlo transport code, MCNP, was used to model the thermal neutron flux distribution in the region around self-powered in-core flux detectors (ICFDs), and in the vicinity of the calandria edge. The ICFD model was used to evaluate the reduction in signal of a given detector (the 'detector shading factor') due to neutron absorption in surrounding materials, detectors, and lead-cables. The calandria edge model was used to infer the accuracy of the calandria edge position from flux scans performed by AECL's traveling flux detector (TFD) system. The MCNP results were checked against experimental results on ICFDs, and also against shading factors computed by other means. The use of improved in-core detector calibration factors obtained by this new methodology will improve the accuracy of spatial flux control performance in CANDU-6 reactors. The accurate determination of TFD based calandria edge position is useful in the quantitative measurement of changes in in-core component dimensions and position due to aging, such as pressure tube sag. (author)

Early Assessment of VIIRS On-Orbit Calibration and Support Activities

Science.gov (United States)

Xiong, Xiaoxiong; Chiang, Kwofu; McIntire, Jeffrey; Oudrari, Hassan; Wu, Aisheng; Schwaller, Mathew; Butler, James

2012-01-01

The Suomi National Polar-orbiting Partnership (S-NPP) satellite, formally the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), provides a bridge between current and future low-Earth orbiting weather and environmental observation satellite systems. The NASA s NPP VIIRS Characterization Support Team (VCST) is designed to assess the long term geometric and radiometric performance of the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument onboard the S-NPP spacecraft and to support NPP Science Team Principal Investigators (PI) for their independent evaluation of VIIRS Environmental Data Records (EDRs). This paper provides an overview of Suomi NPP VIIRS on-orbit calibration activities and examples of sensor initial on-orbit performance. It focuses on the radiometric calibration support activities and capabilities provided by the NASA VCST.

Instrumentation with polarized neutrons

International Nuclear Information System (INIS)

Boeni, P.; Muenzer, W.; Ostermann, A.

2009-01-01

Neutron scattering with polarization analysis is an indispensable tool for the investigation of novel materials exhibiting electronic, magnetic, and orbital degrees of freedom. In addition, polarized neutrons are necessary for neutron spin precession techniques that path the way to obtain extremely high resolution in space and time. Last but not least, polarized neutrons are being used for fundamental studies as well as very recently for neutron imaging. Many years ago, neutron beam lines were simply adapted for polarized beam applications by adding polarizing elements leading usually to unacceptable losses in neutron intensity. Recently, an increasing number of beam lines are designed such that an optimum use of polarized neutrons is facilitated. In addition, marked progress has been obtained in the technology of 3 He polarizers and the reflectivity of large-m supermirrors. Therefore, if properly designed, only factors of approximately 2-3 in neutron intensity are lost. It is shown that S-benders provide neutron beams with an almost wavelength independent polarization. Using twin cavities, polarized beams with a homogeneous phase space and P>0.99 can be produced without significantly sacrificing intensity. It is argued that elliptic guides, which are coated with large m polarizing supermirrors, provide the highest flux.

High accuracy calibration of a dynamic vapor sorption instrument and determination of the equilibrium humidities using single salts

DEFF Research Database (Denmark)

Rörig-Dalgaard, Inge; Svensson, Staffan

2016-01-01

We present a procedure for accurately calibrating a dynamic vapor sorption (DVS) instrument using single salts. The procedure accounts for and tailors distinct calibration tests according to the fundamental properties of each salt. Especially relevant properties influencing the calibration are th...

Calibration and use of the polar organic chemical integrative sampler--a critical review.

Science.gov (United States)

Harman, Christopher; Allan, Ian John; Vermeirssen, Etiënne L M

2012-12-01

The implementation of strict environmental quality standards for polar organic priority pollutants poses a challenge for monitoring programs. The polar organic chemical integrative sampler (POCIS) may help to address the challenge of measuring low and fluctuating trace concentrations of such organic contaminants, offering significant advantages over traditional sampling. In the present review, the authors evaluate POCIS calibration methods and factors affecting sampling rates together with reported environmental applications. Over 300 compounds have been shown to accumulate in POCIS, including pesticides, pharmaceuticals, hormones, and industrial chemicals. Polar organic chemical integrative sampler extracts have been used for both chemical and biological analyses. Several different calibration methods have been described, which makes it difficult to directly compare sampling rates. In addition, despite the fact that some attempts to correlate sampling rates with the properties of target compounds such as log K(OW) have been met with varying success, an overall model that can predict uptake is lacking. Furthermore, temperature, water flow rates, salinity, pH, and fouling have all been shown to affect uptake; however, there is currently no robust method available for adjusting for these differences. Overall, POCIS has been applied to a wide range of sampling environments and scenarios and has been proven to be a useful screening tool. However, based on the existing literature, a more mechanistic approach is required to increase understanding and thus improve the quantitative nature of the measurements. Copyright © 2012 SETAC.

An overview of Suomi NPP VIIRS calibration maneuvers

Science.gov (United States)

Butler, James J.; Xiong, Xiaoxiong; Barnes, Robert A.; Patt, Frederick S.; Sun, Junqiang; Chiang, Kwofu

2012-09-01

The first Visible Infrared Imager Radiometer Suite (VIIRS) instrument was successfully launched on-board the Suomi National Polar-orbiting Partnership (SNPP) spacecraft on October 28, 2011. Suomi NPP VIIRS observations are made in 22 spectral bands, from the visible (VIS) to the long-wave infrared (LWIR), and are used to produce 22 Environmental Data Records (EDRs) with a broad range of scientific applications. The quality of these VIIRS EDRs strongly depends on the quality of its calibrated and geo-located Sensor Date Records (SDRs). Built with a strong heritage to the NASA's EOS MODerate resolution Imaging Spectroradiometer (MODIS) instrument, the VIIRS is calibrated on-orbit using a similar set of on-board calibrators (OBC), including a solar diffuser (SD) and solar diffuser stability monitor (SDSM) system for the reflective solar bands (RSB) and a blackbody (BB) for the thermal emissive bands (TEB). Onorbit maneuvers of the SNPP spacecraft provide additional calibration and characterization data from the VIIRS instrument which cannot be obtained pre-launch and are required to produce the highest quality SDRs. These include multiorbit yaw maneuvers for the characterization of SD and SDSM screen transmission, quasi-monthly roll maneuvers to acquire lunar observations to track sensor degradation in the visible through shortwave infrared, and a driven pitch-over maneuver to acquire multiple scans of deep space to determine TEB response versus scan angle (RVS). This paper provides an overview of these three SNPP calibration maneuvers. Discussions are focused on their potential calibration and science benefits, pre-launch planning activities, and on-orbit scheduling and implementation strategies. Results from calibration maneuvers performed during the Intensive Calibration and Validation (ICV) period for the VIIRS sensor are illustrated. Also presented in this paper are lessons learned regarding the implementation of calibration spacecraft maneuvers on follow

Calibration of passive remote observing optical and microwave instrumentation; Proceedings of the Meeting, Orlando, FL, Apr. 3-5, 1991

Science.gov (United States)

Guenther, Bruce W.

Various papers on the calibration of passive remote observing optical and microwave instrumentation are presented. Individual topics addressed include: on-board calibration device for a wide field-of-view instrument, calibration for the medium-resolution imaging spectrometer, cryogenic radiometers and intensity-stabilized lasers for EOS radiometric calibrations, radiometric stability of the Shuttle-borne solar backscatter ultraviolet spectrometer, ratioing radiometer for use with a solar diffuser, requirements of a solar diffuser and measurements of some candidate materials, reflectance stability analysis of Spectralon diffuse calibration panels, stray light effects on calibrations using a solar diffuser, radiometric calibration of SPOT 23 HRVs, surface and aerosol models for use in radiative transfer codes. Also addressed are: calibrated intercepts for solar radiometers used in remote sensor calibration, radiometric calibration of an airborne multispectral scanner, in-flight calibration of a helicopter-mounted Daedalus multispectral scanner, technique for improving the calibration of large-area sphere sources, remote colorimetry and its applications, spatial sampling errors for a satellite-borne scanning radiometer, calibration of EOS multispectral imaging sensors and solar irradiance variability. (For individual items see A93-23576 to A93-23603)

North Polar Cap

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour. In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime. The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap. Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen

The use of a secondary standard x-ray exposure meter to calibrate a field instrument for use in output measurements

International Nuclear Information System (INIS)

1974-11-01

It is stated that the recommended procedures have been closely correlated with ICRU Report 23 (1973), 'Measurements of absorbed dose in a phantom irradiated by a single beam of X- or gamma-rays'. The present report is contained in sections entitled: introduction; equipment and outline of procedures; calibration and use of field instrument in a phantom; calibration and use of the field instrument in air; local reference instrument; summary of recommended procedures. Appendices are entitled: the Perspex Intercomparison Phantom; the implications of applying an in-air calibration factor to readings made in a water phantom. (U.K.)

BRDF Calibration of Sintered PTFE in the SWIR

Science.gov (United States)

Georgiev, Georgi T.; Butler, James J.

2009-01-01

Satellite instruments operating in the reflective solar wavelength region often require accurate and precise determination of the Bidirectional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in their pre-flight calibrations and ground-based support of on-orbit remote sensing instruments. The Diffuser Calibration Facility at NASA's Goddard Space Flight Center is a secondary diffuser calibration standard after NEST for over two decades, providing numerous NASA projects with BRDF data in the UV, Visible and the NIR spectral regions. Currently the Diffuser Calibration Facility extended the covered spectral range from 900 nm up to 1.7 microns. The measurements were made using the existing scatterometer by replacing the Si photodiode based receiver with an InGaAs-based one. The BRDF data was recorded at normal incidence and scatter zenith angles from 10 to 60 deg. Tunable coherent light source was setup. Broadband light source application is under development. Gray-scale sintered PTFE samples were used at these first trials, illuminated with P and S polarized incident light. The results are discussed and compared to empirically generated BRDF data from simple model based on 8 deg directional/hemispherical measurements.

Preliminary Results of BTDF Calibration of Transmissive Solar Diffusers for Remote Sensing

Science.gov (United States)

Georgiev, Georgi T.; Butler, James J.; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2016-01-01

Satellite instruments operating in the reflected solar wavelength region require accurate and precise determination of the optical properties of their diffusers used in pre-flight and post-flight calibrations. The majority of recent and current space instruments use reflective diffusers. As a result, numerous Bidirectional Reflectance Distribution Function (BRDF) calibration comparisons have been conducted between the National Institute of Standards and Technology (NIST) and other industry and university-based metrology laboratories. However, based on literature searches and communications with NIST and other laboratories, no Bidirectional Transmittance Distribution Function (BTDF) measurement comparisons have been conducted between National Measurement Laboratories (NMLs) and other metrology laboratories. On the other hand, there is a growing interest in the use of transmissive diffusers in the calibration of satellite, air-borne, and ground-based remote sensing instruments. Current remote sensing instruments employing transmissive diffusers include the Ozone Mapping and Profiler Suite instrument (OMPS) Limb instrument on the Suomi-National Polar-orbiting Partnership (S-NPP) platform,, the Geostationary Ocean Color Imager (GOCI) on the Korea Aerospace Research Institute's (KARI) Communication, Ocean, and Meteorological Satellite (COMS), the Ozone Monitoring Instrument (OMI) on NASA's Earth Observing System (EOS) Aura platform, the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument and the Geostationary Environmental Monitoring Spectrometer (GEMS).. This ensemble of instruments requires validated BTDF measurements of their on-board transmissive diffusers from the ultraviolet through the near infrared. This paper presents the preliminary results of a BTDF comparison between the NASA Diffuser Calibration Laboratory (DCL) and NIST on quartz and thin Spectralon samples.

Preliminary results of BTDF calibration of transmissive solar diffusers for remote sensing

Science.gov (United States)

Georgiev, Georgi T.; Butler, James J.; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2016-09-01

Satellite instruments operating in the reflected solar wavelength region require accurate and precise determination of the optical properties of their diffusers used in pre-flight and post-flight calibrations. The majority of recent and current space instruments use reflective diffusers. As a result, numerous Bidirectional Reflectance Distribution Function (BRDF) calibration comparisons have been conducted between the National Institute of Standards and Technology (NIST) and other industry and university-based metrology laboratories. However, based on literature searches and communications with NIST and other laboratories, no Bidirectional Transmittance Distribution Function (BTDF) measurement comparisons have been conducted between National Measurement Laboratories (NMLs) and other metrology laboratories. On the other hand, there is a growing interest in the use of transmissive diffusers in the calibration of satellite, air-borne, and ground-based remote sensing instruments. Current remote sensing instruments employing transmissive diffusers include the Ozone Mapping and Profiler Suite instrument (OMPS) Limb instrument on the Suomi-National Polar-orbiting Partnership (S-NPP) platform,, the Geostationary Ocean Color Imager (GOCI) on the Korea Aerospace Research Institute's (KARI) Communication, Ocean, and Meteorological Satellite (COMS), the Ozone Monitoring Instrument (OMI) on NASA's Earth Observing System (EOS) Aura platform, the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument and the Geostationary Environmental Monitoring Spectrometer (GEMS).. This ensemble of instruments requires validated BTDF measurements of their onboard transmissive diffusers from the ultraviolet through the near infrared. This paper presents the preliminary results of a BTDF comparison between the NASA Diffuser Calibration Laboratory (DCL) and NIST on quartz and thin Spectralon samples.

ORNL calibrations facility

International Nuclear Information System (INIS)

Berger, C.D.; Gupton, E.D.; Lane, B.H.; Miller, J.H.; Nichols, S.W.

1982-08-01

The ORNL Calibrations Facility is operated by the Instrumentation Group of the Industrial Safety and Applied Health Physics Division. Its primary purpose is to maintain radiation calibration standards for calibration of ORNL health physics instruments and personnel dosimeters. This report includes a discussion of the radioactive sources and ancillary equipment in use and a step-by-step procedure for calibration of those survey instruments and personnel dosimeters in routine use at ORNL

Solid laboratory calibration of a nonimaging spectroradiometer.

Science.gov (United States)

Schaepman, M E; Dangel, S

2000-07-20

Field-based nonimaging spectroradiometers are often used in vicarious calibration experiments for airborne or spaceborne imaging spectrometers. The calibration uncertainties associated with these ground measurements contribute substantially to the overall modeling error in radiance- or reflectance-based vicarious calibration experiments. Because of limitations in the radiometric stability of compact field spectroradiometers, vicarious calibration experiments are based primarily on reflectance measurements rather than on radiance measurements. To characterize the overall uncertainty of radiance-based approaches and assess the sources of uncertainty, we carried out a full laboratory calibration. This laboratory calibration of a nonimaging spectroradiometer is based on a measurement plan targeted at achieving a calibration. The individual calibration steps include characterization of the signal-to-noise ratio, the noise equivalent signal, the dark current, the wavelength calibration, the spectral sampling interval, the nonlinearity, directional and positional effects, the spectral scattering, the field of view, the polarization, the size-of-source effects, and the temperature dependence of a particular instrument. The traceability of the radiance calibration is established to a secondary National Institute of Standards and Technology calibration standard by use of a 95% confidence interval and results in an uncertainty of less than ?7.1% for all spectroradiometer bands.

Environmental Assessment for the Health Protection Instrument Calibration Facility at the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

1993-08-01

The purpose of this Environmental Assessment (EA) is to review the possible environmental consequences associated with the construction and operation of a Health Protection Instrument Calibration Facility on the Savannah River Site (SRS). The proposed replacement calibration facility would be located in B Area of SRS and would replace an inadequate existing facility currently located within A Area of SRS (Building 736-A). The new facility would provide laboratories, offices, test equipment and the support space necessary for the SRS Radiation Monitoring Instrument Calibration Program to comply with DOE Orders 5480.4 (Environmental Protection, Safety and Health Protection Standards) and 5480.11 (Radiation Protection for Occupational Workers). The proposed facility would serve as the central site source for the evaluation, selection, inspection, testing, calibration, and maintenance of all SRS radiation monitoring instrumentation. The proposed facility would be constructed on a currently undeveloped portion in B Area of SRS. The exact plot associated with the proposed action is a 1.2 hectare (3 acre) tract of land located on the west side of SRS Road No. 2. The proposed facility would lie approximately 4.4 km (2.75 mi) from the nearest SRS site boundary. The proposed facility would also lie within the confines of the existing B Area, and SRS safeguards and security systems. Archaeological, ecological, and land use reviews have been conducted in connection with the use of this proposed plot of land, and a detailed discussion of these reviews is contained herein. Socioeconomic, operational, and accident analyses were also examined in relation to the proposed project and the findings from these reviews are also contained in this EA.

Environmental Assessment for the Health Protection Instrument Calibration Facility at the Savannah River Site

International Nuclear Information System (INIS)

1993-08-01

The purpose of this Environmental Assessment (EA) is to review the possible environmental consequences associated with the construction and operation of a Health Protection Instrument Calibration Facility on the Savannah River Site (SRS). The proposed replacement calibration facility would be located in B Area of SRS and would replace an inadequate existing facility currently located within A Area of SRS (Building 736-A). The new facility would provide laboratories, offices, test equipment and the support space necessary for the SRS Radiation Monitoring Instrument Calibration Program to comply with DOE Orders 5480.4 (Environmental Protection, Safety and Health Protection Standards) and 5480.11 (Radiation Protection for Occupational Workers). The proposed facility would serve as the central site source for the evaluation, selection, inspection, testing, calibration, and maintenance of all SRS radiation monitoring instrumentation. The proposed facility would be constructed on a currently undeveloped portion in B Area of SRS. The exact plot associated with the proposed action is a 1.2 hectare (3 acre) tract of land located on the west side of SRS Road No. 2. The proposed facility would lie approximately 4.4 km (2.75 mi) from the nearest SRS site boundary. The proposed facility would also lie within the confines of the existing B Area, and SRS safeguards and security systems. Archaeological, ecological, and land use reviews have been conducted in connection with the use of this proposed plot of land, and a detailed discussion of these reviews is contained herein. Socioeconomic, operational, and accident analyses were also examined in relation to the proposed project and the findings from these reviews are also contained in this EA

Lessons Learned from GOSAT; Instrument Design, Calibration, Operation, Data Processing, and International Collaboration

Science.gov (United States)

Kuze, A.; Suto, H.; Shiomi, K.; Nakajima, M.

2012-12-01

Advantage of satellite observation is its ability to monitor long term and global distribution with a single instrument. Ozone observation from space has been successful for long term monitoring purposes. Monitoring gradual increase and distribution of greenhouse gases in the troposphere with sub-percent accuracy has become a challenging subject. Interference of cloud and aerosol in radiative transfer has to be corrected for troposphere measurement. Accurate O2-A band measurement can retrieve surface pressure and aerosol distribution property. We have selected a Fourier Transform spectrometer (FTS) to achieve high throughput and wide spectral coverage with uniform spectral resolution. On the other hand, it is difficult to modulate short wave such as 0.76μm and avoid micro vibration interference. Prelaunch, we took special care to select optical components of excellent surface quality and isolate vibration. Design parameters such as IFOV, spectral resolution, observation interval within limited satellite resources must be carefully optimized. Greenhouse gases Observing SATellite (GOSAT) has been providing global high spectral resolution data for almost 4 years. Instrument performance, radiometric calibration, radiative transfer calculation and laboratory spectroscopy are all important. The first step was to reduce bias of column-averaged dry air mole fractions (the Level 2 product) of CO2 and CH4 (XCO2 and XCH4) and validate using well calibrated data such as TCCON. After 2 years of operation, latitudinal distribution of zonal mean and seasonal variation at these sites can be measured with better than 2ppm accuracy. However, validations are limited to ideal conditions. Next step is to evaluate consistency of measured values from long periods since launch, different surface types, and various input radiance with different instrument gain. For long term radiometric calibration, we have uses vicarious, onboard solar diffuser, and lunar calibration data. Over the ocean

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

for instrument-based PoC blood biomarker analysis systems. Motivated by the complexity of associating high-accuracy biosensing using silicon nanowire field effect transistors with ease of use for the PoC system user, we propose a novel one-step, multipoint calibration method for LoC-based systems. Our approach...... 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...

40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Gas meter or flow instrumentation... Procedures § 86.120-94 Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters...

Characteristics of X ray calibration fields for performance test of radiation measuring instruments

International Nuclear Information System (INIS)

Shimizu, Shigeru; Takahashi, Fumiaki; Sawahata, Tadahiro; Tohnami, Kohichi; Kikuchi, Hiroshi; Murayama, Takashi

1999-02-01

Performance test and calibration of the radiation measuring instruments for low energy photons are made using the X ray calibration fields which are monochromatically characterized by filtration of continuous X ray spectrum. The X ray calibration field needs to be characterized by some quality conditions such as quality index and homogeneity coefficient. The present report describes quality conditions, spectrum and some characteristics of X ray irradiation fields in the Facility of Radiation Standard of the Japan Atomic Energy Research Institute (FRS-JAERI). Fifty nine X ray qualities with the quality index of 0.6, 0.7, 0.8 and 0.9 were set for the tube voltages between 10 kV and 350 kV. Estimation of X ray spectrum measured with a Ge detector was made in terms of exposure, ambient dose equivalent and fluence for all the obtained qualities. Practical irradiation field was determined as the dose distribution uniformity is within ±3%. The obtained results improve the quality of X ray calibration fields and calibration accuracy. (author)

Human-Robot Collaboration Dynamic Impact Testing and Calibration Instrument for Disposable Robot Safety Artifacts.

Science.gov (United States)

Dagalakis, Nicholas G; Yoo, Jae Myung; Oeste, Thomas

2016-01-01

The Dynamic Impact Testing and Calibration Instrument (DITCI) is a simple instrument with a significant data collection and analysis capability that is used for the testing and calibration of biosimulant human tissue artifacts. These artifacts may be used to measure the severity of injuries caused in the case of a robot impact with a human. In this paper we describe the DITCI adjustable impact and flexible foundation mechanism, which allows the selection of a variety of impact force levels and foundation stiffness. The instrument can accommodate arrays of a variety of sensors and impact tools, simulating both real manufacturing tools and the testing requirements of standards setting organizations. A computer data acquisition system may collect a variety of impact motion, force, and torque data, which are used to develop a variety of mathematical model representations of the artifacts. Finally, we describe the fabrication and testing of human abdomen soft tissue artifacts, used to display the magnitude of impact tissue deformation. Impact tests were performed at various maximum impact force and average pressure levels.

Polarization Characteristics Inferred From the Radio Receiver Instrument on the Enhanced Polar Outflow Probe

Science.gov (United States)

Danskin, Donald W.; Hussey, Glenn C.; Gillies, Robert G.; James, H. Gordon; Fairbairn, David T.; Yau, Andrew W.

2018-02-01

The Radio Receiver Instrument (RRI) on the CAScade, Smallsat, and Ionospheric Polar Explorer/enhanced Polar Outflow Probe (CASSIOPE/e-POP) satellite was used to receive continuous wave and binary phase shift keyed transmissions from a high-frequency transmitter located in Ottawa, ON, Canada during April 2016 to investigate how the ionosphere affects the polarization characteristics of transionospheric high-frequency radio waves. The spacecraft orientation was continuously slewed to maintain the dipole orientation in a plane perpendicular to the direction toward the transmitter, enabling the first in situ planar polarization determination for continuous wave and binary phase shift keyed modulated radio waves from space at times when the wave frequency is at least 1.58 times the plasma frequency. The Stokes parameters and polarization characteristics were derived from the measured data and interpreted using an existing ray tracing model. For the southern part of the passes, the power was observed to oscillate between the two dipoles of RRI, which was attributed to Faraday rotation of the radio waves. For the first time, a reversal in the rate of change of orientation angle was observed where the minimum in modeled Faraday rotation occurred. The reversal point was poleward of the point of closest approach between the satellite and transmitter; this was explained by the variations of total electron content and component of magnetic field along the direction of propagation. The received signals show both quasi-longitudinal (QL) and quasi-transverse characteristics. South of the transmitter the QL regime is dominant. Around the reversal point, a combination of QL and quasi-transverse nature was observed.

Activities on calibration of radiation protection instruments in Indonesia

International Nuclear Information System (INIS)

Trijoko, S.

1995-01-01

As the use of the ionizing radiation emitted by radionuclides or produced by modern machines in Indonesia has increased significantly in the past two decades, the demand for radiation protection measures has also grown up very rapidly. In the mind of Indonesian people, ionizing radiation is always associated with atomic bombs. Indonesian government has set up National Atomic Energy Agency (BATAN) through the Act No. 31/1964. The BATAN has responsibility in the research and development, implementation and inspection of the safe use of ionizing radiation for peaceful purposes, and always put a great concern on radiation protection matter. The Center for Standardization and Radiation Safety Research (CSRSR) has been founded to implement research and services in the fields of radiation safety, standardization, dosimetry, radiation health, as well as the application of nuclear techniques to medicine. In order to provide the national reference in terms of radiation dosimetry and calibration, the Secondary Standard Dosimetry Laboratory was completely set up in Jakarta by 1984. As available facilities, radiation instruments and radiation sources are described. Calibration and personal monitoring services are reported. (K.I.)

Jagiellonian University Drift Chamber Calibration and Track Reconstruction in the P349 Antiproton Polarization Experiment

CERN Document Server

Alfs, D; Moskal, P; Zieliński, M; Grzonka, D; Hauenstein, F; Kilian, K; Lersch, D; Ritman, J; Sefzick, T; Oelert, W; Diermaier, M; Widmann, E; Zmeskal, J; Wolke, M; Nadel-Turonski, P; Carmignotto, M; Horn, T; Mkrtchyan, H; Asaturyan, A; Mkrtchyan, A; Tadevosyan, V; Zhamkochyan, S; Malbrunot-Ettenauer, S; Eyrich, W; Zink, A

2017-01-01

The goal of the P349 experiment is to test whether the antiproton production process can be itself a source of antiproton polarization. In this article, we present the motivation and details of the performed measurement. We report on the status of the analysis focusing mainly on calibration of the drift chambers and 3d track reconstruction.

Nitrogen dioxide and kerosene-flame soot calibration of photoacoustic instruments for measurement of light absorption by aerosols

International Nuclear Information System (INIS)

Arnott, W. Patrick; Moosmu''ller, Hans; Walker, John W.

2000-01-01

A nitrogen dioxide calibration method is developed to evaluate the theoretical calibration for a photoacoustic instrument used to measure light absorption by atmospheric aerosols at a laser wavelength of 532.0 nm. This method uses high concentrations of nitrogen dioxide so that both a simple extinction and the photoacoustically obtained absorption measurement may be performed simultaneously. Since Rayleigh scattering is much less than absorption for the gas, the agreement between the extinction and absorption coefficients can be used to evaluate the theoretical calibration, so that the laser gas spectra are not needed. Photoacoustic theory is developed to account for strong absorption of the laser beam power in passage through the resonator. Findings are that the photoacoustic absorption based on heat-balance theory for the instrument compares well with absorption inferred from the extinction measurement, and that both are well within values represented by published spectra of nitrogen dioxide. Photodissociation of nitrogen dioxide limits the calibration method to wavelengths longer than 398 nm. Extinction and absorption at 532 and 1047 nm were measured for kerosene-flame soot to evaluate the calibration method, and the single scattering albedo was found to be 0.31 and 0.20 at these wavelengths, respectively

Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration

Science.gov (United States)

Englert, Christoph R.; Harlander, John M.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Stump, J. Eloise; Hancock, Jed; Peterson, James Q.; Kumler, Jay; Morrow, William H.; Mooney, Thomas A.; Ellis, Scott; Mende, Stephen B.; Harris, Stewart E.; Stevens, Michael H.; Makela, Jonathan J.; Harding, Brian J.; Immel, Thomas J.

2017-10-01

The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument was built for launch and operation on the NASA Ionospheric Connection Explorer (ICON) mission. The instrument was designed to measure thermospheric horizontal wind velocity profiles and thermospheric temperature in altitude regions between 90 km and 300 km, during day and night. For the wind measurements it uses two perpendicular fields of view pointed at the Earth's limb, observing the Doppler shift of the atomic oxygen red and green lines at 630.0 nm and 557.7 nm wavelength. The wavelength shift is measured using field-widened, temperature compensated Doppler Asymmetric Spatial Heterodyne (DASH) spectrometers, employing low order échelle gratings operating at two different orders for the different atmospheric lines. The temperature measurement is accomplished by a multichannel photometric measurement of the spectral shape of the molecular oxygen A-band around 762 nm wavelength. For each field of view, the signals of the two oxygen lines and the A-band are detected on different regions of a single, cooled, frame transfer charge coupled device (CCD) detector. On-board calibration sources are used to periodically quantify thermal drifts, simultaneously with observing the atmosphere. The MIGHTI requirements, the resulting instrument design and the calibration are described.

Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments

Science.gov (United States)

Hagan, David H.; Isaacman-VanWertz, Gabriel; Franklin, Jonathan P.; Wallace, Lisa M. M.; Kocar, Benjamin D.; Heald, Colette L.; Kroll, Jesse H.

2018-01-01

The use of low-cost air quality sensors for air pollution research has outpaced our understanding of their capabilities and limitations under real-world conditions, and there is thus a critical need for understanding and optimizing the performance of such sensors in the field. Here we describe the deployment, calibration, and evaluation of electrochemical sensors on the island of Hawai`i, which is an ideal test bed for characterizing such sensors due to its large and variable sulfur dioxide (SO2) levels and lack of other co-pollutants. Nine custom-built SO2 sensors were co-located with two Hawaii Department of Health Air Quality stations over the course of 5 months, enabling comparison of sensor output with regulatory-grade instruments under a range of realistic environmental conditions. Calibration using a nonparametric algorithm (k nearest neighbors) was found to have excellent performance (RMSE 0.997) across a wide dynamic range in SO2 ( 2 ppm). However, since nonparametric algorithms generally cannot extrapolate to conditions beyond those outside the training set, we introduce a new hybrid linear-nonparametric algorithm, enabling accurate measurements even when pollutant levels are higher than encountered during calibration. We find no significant change in instrument sensitivity toward SO2 after 18 weeks and demonstrate that calibration accuracy remains high when a sensor is calibrated at one location and then moved to another. The performance of electrochemical SO2 sensors is also strong at lower SO2 mixing ratios (pollutant species in other areas (e.g., polluted urban regions), the calibration and validation approaches described here should be widely applicable to a range of pollutants, sensors, and environments.

Depolarization Ratio Profiles Calibration and Observations of Aerosol and Cloud in the Tibetan Plateau Based on Polarization Raman Lidar

Directory of Open Access Journals (Sweden)

Guangyao Dai

2018-03-01

Full Text Available A brief description of the Water vapor, Cloud and Aerosol Lidar (WACAL system is provided. To calibrate the volume linear depolarization ratio, the concept of “ Δ 90 ° -calibration” is applied in this study. This effective and accurate calibration method is adjusted according to the design of WACAL. Error calculations and analysis of the gain ratio, calibrated volume linear depolarization ratio and particle linear depolarization ratio are provided as well. In this method, the influences of the gain ratio, the rotation angle of the plane of polarization and the polarizing beam splitter are discussed in depth. Two groups of measurements with half wave plate (HWP at angles of (0 ° , 45 ° and (22.5 ° , −22.5 ° are operated to calibrate the volume linear depolarization ratio. Then, the particle linear depolarization ratios measured by WACAL and CALIOP (the Cloud-Aerosol Lidar with Orthogonal Polarization during the simultaneous observations were compared. Good agreements are found. The calibration method was applied in the third Tibetan Plateau Experiment of Atmospheric Sciences (TIPEX III in 2013 and 2014 in China. Vertical profiles of the particle depolarization ratio of clouds and aerosol in the Tibetan Plateau were measured with WACAL in Litang (30.03° N, 100.28° E, 3949 m above sea level (a.s.l. in 2013 and Naqu (31.48° N, 92.06° E, 4508 m a.s.l. in 2014. Then an analysis on the polarizing properties of the aerosol, clouds and cirrus over the Tibetan Plateau is provided. The particle depolarization ratio of cirrus clouds varies from 0.36 to 0.52, with a mean value of 0.44 ± 0.04. Cirrus clouds occurred between 5.2 and 12 km above ground level (a.g.l.. The cloud thickness ranges from 0.12 to 2.55 km with a mean thickness of 1.22 ± 0.70 km. It is found that the particle depolarization ratio of cirrus clouds become larger as the height increases. However, the increase rate of the particle depolarization ratio becomes smaller as

Long-term calibration monitoring of Spectralon diffusers BRDF in the air-ultraviolet.

Science.gov (United States)

Georgiev, Georgi T; Butler, James J

2007-11-10

Long-term calibration monitoring of the bidirectional reflectance distribution function (BRDF) of Spectralon diffusers in the air-ultraviolet is presented. Four Spectralon diffusers were monitored in this study. Three of the diffusers, designated as H1, H2, and H3, were used in the prelaunch radiance calibration of the Solar Backscatter Ultraviolet/2 (SBUV/2) satellite instruments on National Oceanic and Atmospheric Administration (NOAA) 14 and 16. A fourth diffuser, designated as the 400 diffuser, was used in the prelaunch calibration of the Ozone Mapping and Profiler Suite (OMPS) instrument scheduled for initial flight in 2009 on the National Polar Orbiting Environmental Satellite System Preparatory Project. The BRDF data of this study were obtained between 1994 and 2005 using the scatterometer located in the National Aeronautics and Space Administration Goddard Space Flight Center Diffuser Calibration Laboratory. The diffusers were measured at 13 wavelengths between 230 and 425 nm at the incident and scatter angles used in the prelaunch calibrations of SBUV/2 and OMPS. Spectral features in the BRDF of Spectralon are also discussed. The comparison shows how the air-ultraviolet BRDF of these Spectralon samples changed over time under clean room deployment conditions.

Self-Calibration of CMB Polarimeters

Science.gov (United States)

Keating, Brian

2013-01-01

Precision measurements of the polarization of the cosmic microwave background (CMB) radiation, especially experiments seeking to detect the odd-parity "B-modes", have far-reaching implications for cosmology. To detect the B-modes generated during inflation the flux response and polarization angle of these experiments must be calibrated to exquisite precision. While suitable flux calibration sources abound, polarization angle calibrators are deficient in many respects. Man-made polarized sources are often not located in the antenna's far-field, have spectral properties that are radically different from the CMB's, are cumbersome to implement and may be inherently unstable over the (long) duration these searches require to detect the faint signature of the inflationary epoch. Astrophysical sources suffer from time, frequency and spatial variability, are not visible from all CMB observatories, and none are understood with sufficient accuracy to calibrate future CMB polarimeters seeking to probe inflationary energy scales of ~1000 TeV. CMB TB and EB modes, expected to identically vanish in the standard cosmological model, can be used to calibrate CMB polarimeters. By enforcing the observed EB and TB power spectra to be consistent with zero, CMB polarimeters can be calibrated to levels not possible with man-made or astrophysical sources. All of this can be accomplished without any loss of observing time using a calibration source which is spectrally identical to the CMB B-modes. The calibration procedure outlined here can be used for any CMB polarimeter.

Reusing Joint Polar Satellite System (jpss) Ground System Components to Process AURA Ozone Monitoring Instrument (omi) Science Products

Science.gov (United States)

Moses, J. F.; Jain, P.; Johnson, J.; Doiron, J. A.

2017-12-01

New Earth observation instruments are planned to enable advancements in Earth science research over the next decade. Diversity of Earth observing instruments and their observing platforms will continue to increase as new instrument technologies emerge and are deployed as part of National programs such as Joint Polar Satellite System (JPSS), Geostationary Operational Environmental Satellite system (GOES), Landsat as well as the potential for many CubeSat and aircraft missions. The practical use and value of these observational data often extends well beyond their original purpose. The practicing community needs intuitive and standardized tools to enable quick unfettered development of tailored products for specific applications and decision support systems. However, the associated data processing system can take years to develop and requires inherent knowledge and the ability to integrate increasingly diverse data types from multiple sources. This paper describes the adaptation of a large-scale data processing system built for supporting JPSS algorithm calibration and validation (Cal/Val) node to a simplified science data system for rapid application. The new configurable data system reuses scalable JAVA technologies built for the JPSS Government Resource for Algorithm Verification, Independent Test, and Evaluation (GRAVITE) system to run within a laptop environment and support product generation and data processing of AURA Ozone Monitoring Instrument (OMI) science products. Of particular interest are the root requirements necessary for integrating experimental algorithms and Hierarchical Data Format (HDF) data access libraries into a science data production system. This study demonstrates the ability to reuse existing Ground System technologies to support future missions with minimal changes.

Online calibration method for condition monitoring of nuclear reactor instrumentations based on electrical signature analysis

International Nuclear Information System (INIS)

Syaiful Bakhri

2013-01-01

Electrical signature analysis currently becomes an alternative in condition monitoring in nuclear power plants not only for stationary components such as sensors, measurement and instrumentation channels, and other components but also for dynamic components such as electric motors, pumps, generator or actuators. In order to guarantee the accuracy, the calibration of monitoring system is a necessary which practically is performed offline, under limited schedules and certain tight procedures. This research aims to introduce online calibration technique for electrical signature condition monitoring in order that the accuracy can be maintained continuously which in turn increases the reactor safety as a whole. The research was performed step by stepin detail from the conventional technique, online calibration using baseline information and online calibration using differential gain adjustment. Online calibration based on differential gain adjustment provides better results than other techniques even tough under extreme gain insertion as well as external disturbances such as supply voltages. (author)

SMAP RADAR Calibration and Validation

Science.gov (United States)

West, R. D.; Jaruwatanadilok, S.; Chaubel, M. J.; Spencer, M.; Chan, S. F.; Chen, C. W.; Fore, A.

2015-12-01

The Soil Moisture Active Passive (SMAP) mission launched on Jan 31, 2015. The mission employs L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Immediately following launch, there was a three month instrument checkout period, followed by six months of level 1 (L1) calibration and validation. In this presentation, we will discuss the calibration and validation activities and results for the L1 radar data. Early SMAP radar data were used to check commanded timing parameters, and to work out issues in the low- and high-resolution radar processors. From April 3-13 the radar collected receive only mode data to conduct a survey of RFI sources. Analysis of the RFI environment led to a preferred operating frequency. The RFI survey data were also used to validate noise subtraction and scaling operations in the radar processors. Normal radar operations resumed on April 13. All radar data were examined closely for image quality and calibration issues which led to improvements in the radar data products for the beta release at the end of July. Radar data were used to determine and correct for small biases in the reported spacecraft attitude. Geo-location was validated against coastline positions and the known positions of corner reflectors. Residual errors at the time of the beta release are about 350 m. Intra-swath biases in the high-resolution backscatter images are reduced to less than 0.3 dB for all polarizations. Radiometric cross-calibration with Aquarius was performed using areas of the Amazon rain forest. Cross-calibration was also examined using ocean data from the low-resolution processor and comparing with the Aquarius wind model function. Using all a-priori calibration constants provided good results with co-polarized measurements matching to better than 1 dB, and cross-polarized measurements matching to about 1 dB in the beta release. During the

Spectrometric methods used in the calibration of radiodiagnostic measuring instruments

Energy Technology Data Exchange (ETDEWEB)

De Vries, W [Rijksuniversiteit Utrecht (Netherlands)

1995-12-01

Recently a set of parameters for checking the quality of radiation for use in diagnostic radiology was established at the calibration facility of Nederlands Meetinstituut (NMI). The establishment of the radiation quality required re-evaluation of the correction factors for the primary air-kerma standards. Free-air ionisation chambers require several correction factors to measure air-kerma according to its definition. These correction factors were calculated for the NMi free-air chamber by Monte Carlo simulations for monoenergetic photons in the energy range from 10 keV to 320 keV. The actual correction factors follow from weighting these mono-energetic correction factors with the air-kerma spectrum of the photon beam. This paper describes the determination of the photon spectra of the X-ray qualities used for the calibration of dosimetric instruments used in radiodiagnostics. The detector used for these measurements is a planar HPGe-detector, placed in the direct beam of the X-ray machine. To convert the measured pulse height spectrum to the actual photon spectrum corrections must be made for fluorescent photon escape, single and multiple compton scattering inside the detector, and detector efficiency. From the calculated photon spectra a number of parameters of the X-ray beam can be calculated. The calculated first and second half value layer in aluminum and copper are compared with the measured values of these parameters to validate the method of spectrum reconstruction. Moreover the spectrum measurements offer the possibility to calibrate the X-ray generator in terms of maximum high voltage. The maximum photon energy in the spectrum is used as a standard for calibration of kVp-meters.

Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging.

Science.gov (United States)

Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui

2018-01-01

We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments

Directory of Open Access Journals (Sweden)

D. H. Hagan

2018-01-01

Full Text Available The use of low-cost air quality sensors for air pollution research has outpaced our understanding of their capabilities and limitations under real-world conditions, and there is thus a critical need for understanding and optimizing the performance of such sensors in the field. Here we describe the deployment, calibration, and evaluation of electrochemical sensors on the island of Hawai`i, which is an ideal test bed for characterizing such sensors due to its large and variable sulfur dioxide (SO2 levels and lack of other co-pollutants. Nine custom-built SO2 sensors were co-located with two Hawaii Department of Health Air Quality stations over the course of 5 months, enabling comparison of sensor output with regulatory-grade instruments under a range of realistic environmental conditions. Calibration using a nonparametric algorithm (k nearest neighbors was found to have excellent performance (RMSE < 7 ppb, MAE < 4 ppb, r2 > 0.997 across a wide dynamic range in SO2 (< 1 ppb, > 2 ppm. However, since nonparametric algorithms generally cannot extrapolate to conditions beyond those outside the training set, we introduce a new hybrid linear–nonparametric algorithm, enabling accurate measurements even when pollutant levels are higher than encountered during calibration. We find no significant change in instrument sensitivity toward SO2 after 18 weeks and demonstrate that calibration accuracy remains high when a sensor is calibrated at one location and then moved to another. The performance of electrochemical SO2 sensors is also strong at lower SO2 mixing ratios (< 25 ppb, for which they exhibit an error of less than 2.5 ppb. While some specific results of this study (calibration accuracy, performance of the various algorithms, etc. may differ for measurements of other pollutant species in other areas (e.g., polluted urban regions, the calibration and validation approaches described here should be widely applicable

Calibration of Flick standards

International Nuclear Information System (INIS)

Thalmann, Ruedi; Spiller, Jürg; Küng, Alain; Jusko, Otto

2012-01-01

Flick standards or magnification standards are widely used for an efficient and functional calibration of the sensitivity of form measuring instruments. The results of a recent measurement comparison have shown to be partially unsatisfactory and revealed problems related to the calibration of these standards. In this paper the influence factors for the calibration of Flick standards using roundness measurement instruments are discussed in detail, in particular the bandwidth of the measurement chain, residual form errors of the device under test, profile distortions due to the diameter of the probing element and questions related to the definition of the measurand. The different contributions are estimated using simulations and are experimentally verified. Also alternative methods to calibrate Flick standards are investigated. Finally the practical limitations of Flick standard calibration are shown and the usability of Flick standards both to calibrate the sensitivity of roundness instruments and to check the filter function of such instruments is analysed. (paper)

Development of SIR-C Ground Calibration Equipment

Science.gov (United States)

Freeman, A.; Azeem, M.; Haub, D.; Sarabandi, K.

1993-01-01

SIR-C/X-SAR is currently scheduled for launch in April 1994. SIR-C is an L-Band and C-Band, multi-polarization spaceborne SAR system developed by NASA/JPL. X- SAR is an X-Band SAR system developed by DARA/ASI. One of the problems involved in calibrating the SIR-C instrument is to make sure that the horizontal (H) and vertical (V) polarized beams are aligned in the azimuth direction, i.e.. that they are pointing in the same direction. This is important if the polarimetric performance specifications for the system are to be met. To solve this problem, we have designed and built a prototype of a low-cost ground receiver capable of recording received power from two antennas, one H-polarized, the other V-polarized. The two signals are mixed to audio then recorded on the left and right stereo channels of a standard audio cassette player. The audio cassette recording can then be played back directly into a Macintosh computer, where it is digitized. Analysis of.

The Calibration Target for the Mars 2020 SHERLOC Instrument: Multiple Science Roles for Future Manned and Unmanned Mars Exploration

Science.gov (United States)

Fries, M.; Bhartia, R.; Beegle, L.; Burton, A.; Ross, A.; Shahar, A.

2014-01-01

The Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument is a deep ultraviolet (UV) Raman/fluorescence instrument selected as part of the Mars 2020 rover instrument suite. SHERLOC will be mounted on the rover arm and its primary role is to identify carbonaceous species in martian samples, which may be selected for inclusion into a returnable sample cache. The SHERLOC instrument will require the use of a calibration target, and by design, multiple science roles will be addressed in the design of the target. Samples of materials used in NASA Extravehicular Mobility unit (EMU, or "space suit") manufacture have been included in the target to serve as both solid polymer calibration targets for SHERLOC instrument function, as well as for testing the resiliency of those materials under martian ambient conditions. A martian meteorite will also be included in the target to serve as a well-characterized example of a martian rock that contains trace carbonaceous material. This rock will be the first rock that we know of that has completed a round trip between planets and will therefore serve an EPO role to attract public attention to science and planetary exploration. The SHERLOC calibration target will address a wide range of NASA goals to include basic science of interest to both the Science Mission Directorate (SMD) and Human Exploration and Operations Mission Directorate (HEOMD).

Calibration of Ground-based Lidar instrument

DEFF Research Database (Denmark)

Yordanova, Ginka; Gómez Arranz, Paula

This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

RECOVERY OF LARGE ANGULAR SCALE CMB POLARIZATION FOR INSTRUMENTS EMPLOYING VARIABLE-DELAY POLARIZATION MODULATORS

Energy Technology Data Exchange (ETDEWEB)

Miller, N. J.; Marriage, T. A.; Appel, J. W.; Bennett, C. L.; Eimer, J.; Essinger-Hileman, T.; Harrington, K.; Rostem, K.; Watts, D. J. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Chuss, D. T. [Department of Physics, Villanova University, 800 E Lancaster, Villanova, PA 19085 (United States); Wollack, E. J.; Fixsen, D. J.; Moseley, S. H.; Switzer, E. R., E-mail: Nathan.J.Miller@nasa.gov [Observational Cosmology Laboratory, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2016-02-20

Variable-delay Polarization Modulators (VPMs) are currently being implemented in experiments designed to measure the polarization of the cosmic microwave background on large angular scales because of their capability for providing rapid, front-end polarization modulation and control over systematic errors. Despite the advantages provided by the VPM, it is important to identify and mitigate any time-varying effects that leak into the synchronously modulated component of the signal. In this paper, the effect of emission from a 300 K VPM on the system performance is considered and addressed. Though instrument design can greatly reduce the influence of modulated VPM emission, some residual modulated signal is expected. VPM emission is treated in the presence of rotational misalignments and temperature variation. Simulations of time-ordered data are used to evaluate the effect of these residual errors on the power spectrum. The analysis and modeling in this paper guides experimentalists on the critical aspects of observations using VPMs as front-end modulators. By implementing the characterizations and controls as described, front-end VPM modulation can be very powerful for mitigating 1/f noise in large angular scale polarimetric surveys. None of the systematic errors studied fundamentally limit the detection and characterization of B-modes on large scales for a tensor-to-scalar ratio of r = 0.01. Indeed, r < 0.01 is achievable with commensurately improved characterizations and controls.

HIGH-FIDELITY RADIO ASTRONOMICAL POLARIMETRY USING A MILLISECOND PULSAR AS A POLARIZED REFERENCE SOURCE

Energy Technology Data Exchange (ETDEWEB)

Van Straten, W., E-mail: vanstraten.willem@gmail.com [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122 (Australia)

2013-01-15

A new method of polarimetric calibration is presented in which the instrumental response is derived from regular observations of PSR J0437-4715 based on the assumption that the mean polarized emission from this millisecond pulsar remains constant over time. The technique is applicable to any experiment in which high-fidelity polarimetry is required over long timescales; it is demonstrated by calibrating 7.2 years of high-precision timing observations of PSR J1022+1001 made at the Parkes Observatory. Application of the new technique followed by arrival time estimation using matrix template matching yields post-fit residuals with an uncertainty-weighted standard deviation of 880 ns, two times smaller than that of arrival time residuals obtained via conventional methods of calibration and arrival time estimation. The precision achieved by this experiment yields the first significant measurements of the secular variation of the projected semimajor axis, the precession of periastron, and the Shapiro delay; it also places PSR J1022+1001 among the 10 best pulsars regularly observed as part of the Parkes Pulsar Timing Array (PPTA) project. It is shown that the timing accuracy of a large fraction of the pulsars in the PPTA is currently limited by the systematic timing error due to instrumental polarization artifacts. More importantly, long-term variations of systematic error are correlated between different pulsars, which adversely affects the primary objectives of any pulsar timing array experiment. These limitations may be overcome by adopting the techniques presented in this work, which relax the demand for instrumental polarization purity and thereby have the potential to reduce the development cost of next-generation telescopes such as the Square Kilometre Array.

Full-Stokes polarimetry with circularly polarized feeds. Sources with stable linear and circular polarization in the GHz regime

Science.gov (United States)

Myserlis, I.; Angelakis, E.; Kraus, A.; Liontas, C. A.; Marchili, N.; Aller, M. F.; Aller, H. D.; Karamanavis, V.; Fuhrmann, L.; Krichbaum, T. P.; Zensus, J. A.

2018-01-01

We present an analysis pipeline that enables the recovery of reliable information for all four Stokes parameters with high accuracy. Its novelty relies on the effective treatment of the instrumental effects even before the computation of the Stokes parameters, contrary to conventionally used methods such as that based on the Müller matrix. For instance, instrumental linear polarization is corrected across the whole telescope beam and significant Stokes Q and U can be recovered even when the recorded signals are severely corrupted by instrumental effects. The accuracy we reach in terms of polarization degree is of the order of 0.1-0.2%. The polarization angles are determined with an accuracy of almost 1°. The presented methodology was applied to recover the linear and circular polarization of around 150 active galactic nuclei, which were monitored between July 2010 and April 2016 with the Effelsberg 100-m telescope at 4.85 GHz and 8.35 GHz with a median cadence of 1.2 months. The polarized emission of the Moon was used to calibrate the polarization angle measurements. Our analysis showed a small system-induced rotation of about 1° at both observing frequencies. Over the examined period, five sources have significant and stable linear polarization; three sources remain constantly linearly unpolarized; and a total of 11 sources have stable circular polarization degree mc, four of them with non-zero mc. We also identify eight sources that maintain a stable polarization angle. All this is provided to the community for future polarization observations reference. We finally show that our analysis method is conceptually different from those traditionally used and performs better than the Müller matrix method. Although it has been developed for a system equipped with circularly polarized feeds, it can easily be generalized to systems with linearly polarized feeds as well. The data used to create Fig. C.1 are only available at the CDS via anonymous ftp to http

The standard calibration instrument automation system for the atomic absorption spectrophotometer. Part 3: Program documentation

Science.gov (United States)

Ryan, D. P.; Roth, G. S.

1982-04-01

Complete documentation of the 15 programs and 11 data files of the EPA Atomic Absorption Instrument Automation System is presented. The system incorporates the following major features: (1) multipoint calibration using first, second, or third degree regression or linear interpolation, (2) timely quality control assessments for spiked samples, duplicates, laboratory control standards, reagent blanks, and instrument check standards, (3) reagent blank subtraction, and (4) plotting of calibration curves and raw data peaks. The programs of this system are written in Data General Extended BASIC, Revision 4.3, as enhanced for multi-user, real-time data acquisition. They run in a Data General Nova 840 minicomputer under the operating system RDOS, Revision 6.2. There is a functional description, a symbol definitions table, a functional flowchart, a program listing, and a symbol cross reference table for each program. The structure of every data file is also detailed.

Radiometric calibration of a polarization-sensitive sensor

International Nuclear Information System (INIS)

Ahmad, S.P.; Markham, B.L.

1992-01-01

The radiometric accuracy of a sensor is adversely affected by scene polarization if its optical system is sensitive to polarization. Tests performed on the reflective bands of the NS001 Thematic Mapper simulator, an aircraft multispectral scanner, show that it is very sensitive to the polarization state of the incoming radiations. For 100 percent linearly polarized light, errors in the measured intensity vary from -40 to +40 percent, depending on the scan angle and spectral band. To estimate polarization-induced errors in the intensity measured at aircraft level, the intensity and polarization of the atmospheric radiances were simulated using a realistic earth-atmosphere radiative transfer model. For the polarization of atmospheric radiances in the solar meridian plane over a vegetated target, intensity errors may range from -10 to + 10 percent. The polarization-induced errors are highest in the shortest NS001 spectral band (0.450-0.525 microns) because of large atmospheric polarizations contributed by Rayleigh particles and small diluting effects caused by the small contributions of weakly polarized radiations coming from aerosols and the surface. Depending on the illumination and view angles, the errors in derived surface reflectance due to the radiance errors can be very large. In particular, for large off-nadir view angles in the forward scattered direction when the sun is low, the relative errors in the derived surface reflectance can be as large as 4 to 5 times the relative error in the radiances. Polarization sensitivity errors cannot be neglected for the shorter wavelengths when the surface reflectance contribution to atmospheric radiances is very small. 40 refs

Project of an integrated calibration laboratory of instruments at IPEN; Projeto de um laboratorio integrado de calibracao de instrumentos no IPEN

Energy Technology Data Exchange (ETDEWEB)

Barros, Gustavo Adolfo San Jose

2009-07-01

The Calibration Laboratory of Instruments of Instituto de Pesquisas Energeticas e Nucleares offers calibration services of radiation detectors used in radioprotection, diagnostic radiology and radiotherapy, for IPEN and for external facilities (public and private). One part of its facilities is located in the main building, along with other laboratories and study rooms, and another part in an isolated building called Bunker. For the optimization, modernization and specially the safety, the laboratories in the main building shall be transferred to an isolated place. In this work, a project of an integrated laboratory for calibration of instruments was developed, and it will be an expansion of the current Calibration Laboratory of Instruments of IPEN. Therefore, a series of radiometric monitoring of the chosen localization of the future laboratory was realized, and all staff needs (dimensions and disposition of the study rooms and laboratories) were defined. In this project, the laboratories with X ray equipment, alpha and beta radiation sources were located at an isolated part of the building, and the wall shielding was determined, depending on the use of each laboratory. (author)

Development of a neutron-polarizing device based on a quadrupole magnet and its application to a focusing SANS instrument

International Nuclear Information System (INIS)

Oku, Takayuki

2009-01-01

We have investigated suitable magnetic field distribution to polarize neutrons based only on the electromagnetic interaction between a neutron magnetic moment and magnetic field, and found out a quadrupole field was the most suitable among simple multipole fields. Then we constructed a quadrupole magnet with a Halbach magnetic circuit as the neutron polarizing device. A cold neutron polarizing experiment of the quadrupole magnet was performed at the beamline C3-1-2-1 (NOP) of JRR-3 at JAEA. By passing through the aperture of the quadrupole magnet, positive and negative polarity neutrons are accelerated in opposite directions and spatially separated. Therefore, we extracted the one-spin component and analyzed its polarization degree. As a result very high neutron polarization degree P=0.9993±0.0025 was obtained. Then the quadrupole magnet was installed into the polarized neutron focusing geometry SANS instrument SANS-J-II of JRR-3. The instrument performance was enhanced by about 10 times compared with the case with the magnetic supermirror as the neutron polarizing device. The details are shown and discussed. (author)

Preparation of high purity plutonium oxide for radiochemistry instrument calibration standards and working standards

International Nuclear Information System (INIS)

Wong, A.S.; Stalnaker, N.D.

1997-04-01

Due to the lack of suitable high level National Institute of Standards and Technology (NIST) traceable plutonium solution standards from the NIST or commercial vendors, the CST-8 Radiochemistry team at Los Alamos National Laboratory (LANL) has prepared instrument calibration standards and working standards from a well-characterized plutonium oxide. All the aliquoting steps were performed gravimetrically. When a 241 Am standardized solution obtained from a commercial vendor was compared to these calibration solutions, the results agreed to within 0.04% for the total alpha activity. The aliquots of the plutonium standard solutions and dilutions were sealed in glass ampules for long term storage

Calibration of Ground -based Lidar instrument

DEFF Research Database (Denmark)

Villanueva, Héctor; Yordanova, Ginka

This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...

SANS polarization analysis at V4 SANS instrument of HMI Berlin

International Nuclear Information System (INIS)

Keiderling, U; Wiedenmann, A; Rupp, A; Klenke, J; Heil, W

2008-01-01

The V4 instrument has recently been upgraded with a 3 He spin filter cell, placed directly in the homogeneous field B of the sample magnet, to enhance the SANSPOL option for polarization analysis. The prototype setup was still affected by: (a) a quick relaxation of the 3 He nuclear polarization in the cell with a time constant of only ≈130 min which significantly changes the spin filter transmissions T + and T − for neutrons polarized parallel I + and anti-parallel I − to B, and (b) the absence of a flipping aid behind the sample. The usual polarization analysis procedure, expecting virtually time-independent transmissions and a second flipping device, is therefore not applicable. We present an alternative way of polarization analysis, developed especially for this case of a spin filter cell with insufficient time stability, and not requiring a second flipper. A concentrated Co-ferrofluid sample 'MFT3N' was measured with the spin filter cell for 5.5 h. From the time-dependent change of I + and I − caused by the change of T + and T − , the spin-flip and non-spin-flip components of the scattering were calculated by fitting procedures. The two-dimensional flip patterns obtained represent the purely magnetic scattering contribution, featuring the typical (sin αcos α) 2 angular behavior expected for superparamagnetic systems

Determination of absorbed dose calibration factors for therapy level electron beam ionization chambers.

Science.gov (United States)

McEwen, M R; Williams, A J; DuSautoy, A R

2001-03-01

Over several years the National Physical Laboratory (NPL) has been developing an absorbed dose calibration service for electron beam radiotherapy. To test this service, a number of trial calibrations of therapy level electron beam ionization chambers have been carried out during the last 3 years. These trials involved 17 UK radiotherapy centres supplying a total of 46 chambers of the NACP, Markus, Roos and Farmer types. Calibration factors were derived from the primary standard calorimeter at seven energies in the range 4 to 19 MeV with an estimated uncertainty of +/-1.5% at the 95% confidence level. Investigations were also carried out into chamber perturbation, polarity effects, ion recombination and repeatability of the calibration process. The instruments were returned to the radiotherapy centres for measurements to be carried out comparing the NPL direct calibration with the 1996 IPEMB air kerma based Code of Practice. It was found that, in general, all chambers of a particular type showed the same energy response. However, it was found that polarity and recombination corrections were quite variable for Markus chambers-differences in the polarity correction of up to 1% were seen. Perturbation corrections were obtained and were found to agree well with the standard data used in the IPEMB Code. The results of the comparison between the NPL calibration and IPEMB Code show agreement between the two methods at the +/-1% level for the NACP and Farmer chambers, but there is a significant difference for the Markus chambers of around 2%. This difference between chamber types is most likely to be due to the design of the Markus chamber.

Flux-gate magnetometer spin axis offset calibration using the electron drift instrument

International Nuclear Information System (INIS)

Plaschke, Ferdinand; Nakamura, Rumi; Baumjohann, Wolfgang; Steller, Manfred; Magnes, Werner; Leinweber, Hannes K; Chutter, Mark; Vaith, Hans

2014-01-01

Spin-stabilization of spacecraft immensely supports the in-flight calibration of on-board flux-gate magnetometers (FGMs). From 12 calibration parameters in total, 8 can be easily obtained by spectral analysis. From the remaining 4, the spin axis offset is known to be particularly variable. It is usually determined by analysis of Alfvénic fluctuations that are embedded in the solar wind. In the absence of solar wind observations, the spin axis offset may be obtained by comparison of FGM and electron drift instrument (EDI) measurements. The aim of our study is to develop methods that are readily usable for routine FGM spin axis offset calibration with EDI. This paper represents a major step forward in this direction. We improve an existing method to determine FGM spin axis offsets from EDI time-of-flight measurements by providing it with a comprehensive error analysis. In addition, we introduce a new, complementary method that uses EDI beam direction data instead of time-of-flight data. Using Cluster data, we show that both methods yield similarly accurate results, which are comparable yet more stable than those from a commonly used solar wind-based method. (paper)

Intercomparison and calibration of dose calibrators used in nuclear medicine facilities

CERN Document Server

Costa, A M D

2003-01-01

The aim of this work was to establish a working standard for intercomparison and calibration of dose calibrators used in most of nuclear medicine facilities for the determination of the activity of radionuclides administered to patients in specific examinations or therapeutic procedures. A commercial dose calibrator, a set of standard radioactive sources, and syringes, vials and ampoules with radionuclide solutions used in nuclear medicine were utilized in this work. The commercial dose calibrator was calibrated for radionuclide solutions used in nuclear medicine. Simple instrument tests, such as linearity response and variation response with the source volume at a constant source activity concentration were performed. This instrument may be used as a reference system for intercomparison and calibration of other activity meters, as a method of quality control of dose calibrators utilized in nuclear medicine facilities.

Neutron xyz - polarization analysis at a time-of-flight instrument

Energy Technology Data Exchange (ETDEWEB)

Ehlers, Georg [ORNL; Stewart, John Ross [ISIS Facility, Rutherford Appleton Laboratory; Andersen, Ken [ESS

2015-01-01

When implementing a dedicated polarization analysis setup at a neutron time-of-flight instrument with a large area detector, one faces enormous challenges. Nevertheless, significant progress has been made towards this goal over the last few years. This paper addresses systematic limitations of the traditional method that is used to make these measurements, and a possible strategy to overcome these limitations. This will be important, for diffraction as well as inelastic experiments, where the scattering occurs mostly out-of-plane.

Micro-Arcsec mission: implications of the monitoring, diagnostic and calibration of the instrument response in the data reduction chain. .

Science.gov (United States)

Busonero, D.; Gai, M.

The goals of 21st century high angular precision experiments rely on the limiting performance associated to the selected instrumental configuration and observational strategy. Both global and narrow angle micro-arcsec space astrometry require that the instrument contributions to the overall error budget has to be less than the desired micro-arcsec level precision. Appropriate modelling of the astrometric response is required for optimal definition of the data reduction and calibration algorithms, in order to ensure high sensitivity to the astrophysical source parameters and in general high accuracy. We will refer to the framework of the SIM-Lite and the Gaia mission, the most challenging space missions of the next decade in the narrow angle and global astrometry field, respectively. We will focus our dissertation on the Gaia data reduction issues and instrument calibration implications. We describe selected topics in the framework of the Astrometric Instrument Modelling for the Gaia mission, evidencing their role in the data reduction chain and we give a brief overview of the Astrometric Instrument Model Data Analysis Software System, a Java-based pipeline under development by our team.

Errors and corrections in the separation of spin-flip and non-spin-flip thermal neutron scattering using the polarization analysis technique

International Nuclear Information System (INIS)

Williams, W.G.

1975-01-01

The use of the polarization analysis technique to separate spin-flip from non-spin-flip thermal neutron scattering is especially important in determining magnetic scattering cross-sections. In order to identify a spin-flip ratio in the scattering with a particular scattering process, it is necessary to correct the experimentally observed 'flipping-ratio' to allow for the efficiencies of the vital instrument components (polarizers and spin-flippers), as well as multiple scattering effects in the sample. Analytical expressions for these corections are presented and their magnitudes in typical cases estimated. The errors in measurement depend strongly on the uncertainties in the calibration of the efficiencies of the polarizers and the spin-flipper. The final section is devoted to a discussion of polarization analysis instruments

Instrument Calibration and Certification Procedure

Energy Technology Data Exchange (ETDEWEB)

Davis, R. Wesley [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-05-31

The Amptec 640SL-2 is a 4-wire Kelvin failsafe resistance meter, designed to reliably use very low-test currents for its resistance measurements. The 640SL-1 is a 2-wire version, designed to support customers using the Reynolds Industries type 311 connector. For both versions, a passive (analog) dual function DC Milliameter/Voltmeter allows the user to verify the actual 640SL output current level and the open circuit voltage on the test leads. This procedure includes tests of essential performance parameters. Any malfunction noticed during calibration, whether specifically tested for or not, shall be corrected before calibration continues or is completed.

Long range radio tracking of sea turtles and polar bear: Instrumentation and preliminary results

Science.gov (United States)

Baldwin, H. A.

1972-01-01

Instrumentation developed for studies of path behavior of the green sea turtle and migration movement of polar bear is described. Preliminary results bearing on navigation ability in these species are presented. Both species operate in difficult environments, and the problems faced in the design of electronic instrumentation for these studies are not completely specified at this time. However, the critical factors yet to be understood are primarily related to the behavior of instrumented animals. The data obtained with these experimental techniques are included, first to illustrate the technique and, second to provide initial preliminary results bearing on animal navigation.

Evaluation applications of instrument calibration research findings in psychology for very small samples

Science.gov (United States)

Fisher, W. P., Jr.; Petry, P.

2016-11-01

Many published research studies document item calibration invariance across samples using Rasch's probabilistic models for measurement. A new approach to outcomes evaluation for very small samples was employed for two workshop series focused on stress reduction and joyful living conducted for health system employees and caregivers since 2012. Rasch-calibrated self-report instruments measuring depression, anxiety and stress, and the joyful living effects of mindfulness behaviors were identified in peer-reviewed journal articles. Items from one instrument were modified for use with a US population, other items were simplified, and some new items were written. Participants provided ratings of their depression, anxiety and stress, and the effects of their mindfulness behaviors before and after each workshop series. The numbers of participants providing both pre- and post-workshop data were low (16 and 14). Analysis of these small data sets produce results showing that, with some exceptions, the item hierarchies defining the constructs retained the same invariant profiles they had exhibited in the published research (correlations (not disattenuated) range from 0.85 to 0.96). In addition, comparisons of the pre- and post-workshop measures for the three constructs showed substantively and statistically significant changes. Implications for program evaluation comparisons, quality improvement efforts, and the organization of communications concerning outcomes in clinical fields are explored.

Instrumentation report 1: specification, design, calibration, and installation of instrumentation for an experimental, high-level, nuclear waste storage facility

International Nuclear Information System (INIS)

Brough, W.G.; Patrick, W.C.

1982-01-01

The Spent Fuel Test-Climax (SFT-C) is being conducted 420 m underground at the Nevada Test Site under the auspices of the US Department of Energy. The test facility houses 11 spent fuel assemblies from an operating commercial nuclear reactor and numerous other thermal sources used to simulate the near-field effects of a large repository. We developed a large-scale instrumentation plan to ensure that a sufficient quality and quantity of data were acquired during the three- to five-year test. These data help satisfy scientific, operational, and radiation safety objectives. Over 800 data channels are being scanned to measure temperature, electrical power, radiation, air flow, dew point, stress, displacement, and equipment operation status (on/off). This document details the criteria, design, specifications, installation, calibration, and current performance of the entire instrumentation package

Laboratory for Calibration of Gamma Radiation Measurement Instruments (LabCal) of Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN) from Brazilian Army Technology Center (CTEx)

International Nuclear Information System (INIS)

Amorim, Aneuri de; Balthar, Mario Cesar V.; Santos, Avelino; Vilela, Paulo Ricardo T. de; Oliveira, Luciano Santa Rita; Penha, Paulo Eduardo C. de Oliveira; Gonzaga, Roberto Neves; Andrade, Edson Ramos de; Oliveira, Celio Jorge Vasques de; Fagundes, Luiz Cesar S.

2016-01-01

This paper describes the calibration laboratory deployment steps (LABCAL) gamma ionizing radiation measuring instruments in the Army Technology Center, CTEx. Initially the calibration of radiation monitors will be held in the dosimetric quantity air kerma and operational quantity ambient dose equivalent H*(d). The LABCAL / CTEx has not yet authorized by CASEC / CNEN. This laboratory aims to calibrate the ionizing radiation instruments used by the Brazilian Army. (author)

Preparation of the Atlas experiment: electronic calibration of the electromagnetic calorimeter, measurement of the W boson polarization in top quark decay

International Nuclear Information System (INIS)

Labbe, J.

2009-07-01

The CERN Large Hadron Collider (LHC) will probe the fundamental constituents of matter at an unprecedented microscopic scale. This instrument will lead to further tests and constraints of the Standard Model and its potential extensions at the energies of few TeV. The ATLAS experiment is therefore installed at one of the four interaction points of the LHC. The top quark will be abundantly produced at LHC. Competitive results on its production and decay mechanisms should be quickly obtained. Unlike the other quarks, the top quark does not have time to hadronize before it decays, then allowing spin effects to be measured. It decays into a W boson and a bottom quark, which are polarized by the parity symmetry violation of the weak interaction. In this thesis, the polarization of the W bosons produced in the decay of top quark pairs into a charged lepton and many jets is studied. This measurement is performed by predicting the experimental angular distribution of the charged lepton for each helicity state of the W boson. It allows to constraint the interaction vertex between the top quark, the W boson and bottom quark. The sensitivity of the ATLAS experiment on anomalous couplings of this vertex is estimated in a generic, model-independent, approach. The validation of ATLAS's results will require a good knowledge of all its instruments. Its electromagnetic calorimeter is in particular characterized with an electronic calibration. This thesis presents the jitter and crosstalk studies realized on the ATLAS electromagnetic calorimeter during its final installation. Moreover, the interest of crosstalk analyzes for problematic channels identification is shown. The slides made for the defence of the thesis have been added at the end of the document. (author)

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

International Nuclear Information System (INIS)

Gaytan G, E.; Rivero G, T.; Cruz E, P.; Tovar M, V.M.; Vergara M, F.J.

2007-01-01

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)

IASI instrument: technical description and measured performances

Science.gov (United States)

Hébert, Ph.; Blumstein, D.; Buil, C.; Carlier, T.; Chalon, G.; Astruc, P.; Clauss, A.; Siméoni, D.; Tournier, B.

2017-11-01

IASI is an infrared atmospheric sounder. It will provide meteorologist and scientific community with atmospheric spectra. The IASI system includes 3 instruments that will be mounted on the Metop satellite series, a data processing software integrated in the EPS (EUMETSAT Polar System) ground segment and a technical expertise centre implemented in CNES Toulouse. The instrument is composed of a Fourier transform spectrometer and an associated infrared imager. The optical configuration is based on a Michelson interferometer and the interferograms are processed by an on-board digital processing subsystem, which performs the inverse Fourier transforms and the radiometric calibration. The infrared imager co-registers the IASI soundings with AVHRR imager (AVHRR is another instrument on the Metop satellite). The presentation will focus on the architectures of the instrument, the description of the implemented technologies and the measured performance of the first flight model. CNES is leading the IASI program in association with EUMETSAT. The instrument Prime is ALCATEL SPACE.

Health physics instrument manual

International Nuclear Information System (INIS)

Gupton, E.D.

1978-08-01

The purpose of this manual is to provide apprentice health physics surveyors and other operating groups not directly concerned with radiation detection instruments a working knowledge of the radiation detection and measuring instruments in use at the Laboratory. The characteristics and applications of the instruments are given. Portable instruments, stationary instruments, personnel monitoring instruments, sample counters, and miscellaneous instruments are described. Also, information sheets on calibration sources, procedures, and devices are included. Gamma sources, beta sources, alpha sources, neutron sources, special sources, a gamma calibration device for badge dosimeters, and a calibration device for ionization chambers are described

The Harvard experiment on OSO-6 - Instrumentation, calibration, operation, and description of observations.

Science.gov (United States)

Huber, M. C. E.; Dupree, A. K.; Goldberg, L.; Parkinson, W. H.; Reeves, E. M.; Withbroe, G. L.; Noyes, R. W.

1973-01-01

The Harvard experiment carried by OSO-6 was an extreme-ultraviolet (EUV) spectrometer-spectroheliometer with a wavelength range of 285 to 1385 A, a spatial and spectral bandwidth of 35 x 35(arc sec) squared and 3 A, respectively. The instrument acquired data that have been deposited with the National Space Science Data Center and World Data Center A at the Goddard Space Flight Center in Greenbelt, Maryland, and are now available in their entirety to the scientific community. Aspects of the experiment that are relevant to potential users of the data are described - namely, instrument configuration and parameters, laboratory and inflight calibrations, as well as operational capabilities and procedures. The observations obtained are reported, and the nature, number, and dates of observation, where relevant, are listed.

Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST) Instrument Handbook

Energy Technology Data Exchange (ETDEWEB)

Flynn, Connor J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Radiation Measurement (ARM) Program

2016-03-01

The Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST) measures the absolute infrared (IR) spectral radiance (watts per square meter per steradian per wavenumber) of the sky directly above the instrument. More information about the instrument can be found through the manufacturer’s website. The spectral measurement range of the instrument is 3300 to 520 wavenumbers (cm^-1) or 3-19.2 microns for the normal-range instruments and 3300 to 400 cm^-1 or 3-25 microns, for the extended-range polar instruments. Spectral resolution is 1.0 cm^-1. Instrument field-of-view is 1.3 degrees. Calibrated sky radiance spectra are produced on cycle of about 141 seconds with a group of 6 radiance spectra zenith having dwell times of about 14 seconds each interspersed with 55 seconds of calibration and mirror motion. The ASSIST data is comparable to the Atmospheric Emitted Radiance Interferometer (AERI) data and can be used for 1) evaluating line-by-line radiative transport codes, 2) detecting/quantifying cloud effects on ground-based measurements of infrared spectral radiance (and hence is valuable for cloud property retrievals), and 3) calculating vertical atmospheric profiles of temperature and water vapor and the detection of trace gases.

Radioactive concrete sources at IRD/CNEN, Brazil, for calibration of uranium exploration and environmental field instruments

International Nuclear Information System (INIS)

Barreto, P.M.C.; Campos, C.A.; Malheiros, T.M.M.; Locborg, L.

1988-01-01

A radiometric calibration system consisting of eight radioactive concrete sources was constructed at the Institute of Radiation Protection and Dosimetry (IRD) of the Brazilian Nuclear Energy Commission (CNEN). These sources, stimulating rock outcrops, are available to geophysicists interested in uranium explotation and scientists working with natural radioactivity in environmental research. The sources are of cylindrical shape with 3m diameter and 0.5m thickness weighing approximately 7.5 tonnes each. They are disposed in a circle having in its centre a 4m diameter water pond for cosmi-ray and instrument noise corrections. Uranium, thorium and potassium ores were added to the concrete under such conditions as to achieve perfect homogenization. One hundred and four samples were collected and analysed by eight laboratories. In addition, in-situ radiometric grade determination were performed with calibrated instruments resulting a total of 2.100 determinations of U, Th and K, from which the reference values were assigned to each source. With this system, it is possible to calculate sensitivity constants and stripping ratios for portable gamma-ray spectrometers. It also provides excellent means for the calibration of radiation detectors used in environmental monitoring, in which humidity, temperature and omni-directional gamma flux, similar to the natural environmental, are simulated. (author) [pt

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.

SPRT Calibration Uncertainties and Internal Quality Control at a Commercial SPRT Calibration Facility

Science.gov (United States)

Wiandt, T. J.

2008-06-01

The Hart Scientific Division of the Fluke Corporation operates two accredited standard platinum resistance thermometer (SPRT) calibration facilities, one at the Hart Scientific factory in Utah, USA, and the other at a service facility in Norwich, UK. The US facility is accredited through National Voluntary Laboratory Accreditation Program (NVLAP), and the UK facility is accredited through UKAS. Both provide SPRT calibrations using similar equipment and procedures, and at similar levels of uncertainty. These uncertainties are among the lowest available commercially. To achieve and maintain low uncertainties, it is required that the calibration procedures be thorough and optimized. However, to minimize customer downtime, it is also important that the instruments be calibrated in a timely manner and returned to the customer. Consequently, subjecting the instrument to repeated calibrations or extensive repeated measurements is not a viable approach. Additionally, these laboratories provide SPRT calibration services involving a wide variety of SPRT designs. These designs behave differently, yet predictably, when subjected to calibration measurements. To this end, an evaluation strategy involving both statistical process control and internal consistency measures is utilized to provide confidence in both the instrument calibration and the calibration process. This article describes the calibration facilities, procedure, uncertainty analysis, and internal quality assurance measures employed in the calibration of SPRTs. Data will be reviewed and generalities will be presented. Finally, challenges and considerations for future improvements will be discussed.

Detecting Changing Polarization Structures in Sagittarius A* with High Frequency VLBI

Science.gov (United States)

Fish, Vincent L.; Doeleman, Sheperd S.; Broderick, Avery E.; Loeb, Abraham; Rogers, Alan E. E.

2009-12-01

Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A* exhibits time-variable linear polarization on timescales corresponding to errors. Although the source-integrated linear polarization fraction in the models is typically only a few percent, the linear polarization fraction on small angular scales can be much higher, enabling the detection of changes in the polarimetric structure of Sgr A* on a wide variety of baselines. The shortest baselines track the source-integrated linear polarization fraction, while longer baselines are sensitive to polarization substructures that are beam-diluted by connected-element interferometry. The detection of periodic variability in source polarization should not be significantly affected even if instrumental polarization terms cannot be calibrated out. As more antennas are included in the (sub)millimeter-VLBI array, observations with full polarization will provide important new diagnostics to help disentangle intrinsic source polarization from Faraday rotation effects in the accretion and outflow region close to the black hole event horizon.

Error Budget for a Calibration Demonstration System for the Reflected Solar Instrument for the Climate Absolute Radiance and Refractivity Observatory

Science.gov (United States)

Thome, Kurtis; McCorkel, Joel; McAndrew, Brendan

2013-01-01

A goal of the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission is to observe highaccuracy, long-term climate change trends over decadal time scales. The key to such a goal is to improving the accuracy of SI traceable absolute calibration across infrared and reflected solar wavelengths allowing climate change to be separated from the limit of natural variability. The advances required to reach on-orbit absolute accuracy to allow climate change observations to survive data gaps exist at NIST in the laboratory, but still need demonstration that the advances can move successfully from to NASA and/or instrument vendor capabilities for spaceborne instruments. The current work describes the radiometric calibration error budget for the Solar, Lunar for Absolute Reflectance Imaging Spectroradiometer (SOLARIS) which is the calibration demonstration system (CDS) for the reflected solar portion of CLARREO. The goal of the CDS is to allow the testing and evaluation of calibration approaches, alternate design and/or implementation approaches and components for the CLARREO mission. SOLARIS also provides a test-bed for detector technologies, non-linearity determination and uncertainties, and application of future technology developments and suggested spacecraft instrument design modifications. The resulting SI-traceable error budget for reflectance retrieval using solar irradiance as a reference and methods for laboratory-based, absolute calibration suitable for climatequality data collections is given. Key components in the error budget are geometry differences between the solar and earth views, knowledge of attenuator behavior when viewing the sun, and sensor behavior such as detector linearity and noise behavior. Methods for demonstrating this error budget are also presented.

Development and implantation of a control and data acquisition program for the calibration of instruments for diagnostic radiology

International Nuclear Information System (INIS)

Betti, Flavio

2007-01-01

Design techniques of an automatic control system implementing corrected kerma determination and shutter command in the calibration laboratory at IPEN are shown, as well as the periodic calibration program developed for a monitor chamber for several X-ray beam qualities used for diagnostic radiology and radiation protection instruments. Two reference electrometers, a multichannel secondary standard thermometer, and an absolute pressure barometer were connected to the Rs-232 interface from a PC computer equipped with a National Instruments multi function analog and digital I/O card. LabVIEW MR was chosen as programming tool, which allowed for the development of a suite of programs for both controlling the shutter timing cycles and the calibration of the monitor chamber against a reference standard. A detailed description of the methods used for troubleshooting, fine tuning of parameters and evaluation of program results is followed by an analysis showing that considerable advantages regarding reduction of time and precision improvements during the calibrations could be achieved by the use of the developed programs, particularly under adverse conditions like those found during short expositions, or instead during long irradiation intervals where fluctuation of parameters like kerma rate or room conditions (temperature or pressure) can be found. (author)

MAGNETIC GRADIOMETRY: Instrumentation, Calibration and Applications

DEFF Research Database (Denmark)

Merayo, Jose Maria Garcia

is to be used in the forthcoming satellites CHAMP and SAC-C. Linearity, thermal, radiation, dynamic and calibration tests are carried out to qualify the magnetometer in order to ensure state-of-the-art performance with subnanotesla precision. The overall calibration of the gradiometer yields an omnidirectional...... absolute accuracy of 93pT/m.The scalar calibration of a vector magnetometer is explained thoroughly. The novel method is simple and it represents the most robust and unique way to estimate the characterizing 9 parameters of a vector magnetometer. Its power relies on the linearization of the parametrization...... and offers the possibility of separating the geomagnetic field sources.By using tensor algebra the spherical harmonic expansion of the magnetic field in a curl free region and its associated gradient tensor are derived. This differential tensor quantity is then expressed by spherical coordinates...

Design and Ground Calibration of the Helioseismic and Magnetic Imager (HMI) Instrument on the Solar Dynamics Observatory (SDO)

Science.gov (United States)

Schou, J.; Scherrer, P. H.; Bush, R. I.; Wachter, R.; Couvidat, S.; Rabello-Soares, M. C.; Bogart, R. S.; Hoeksema, J. T.; Liu, Y.; Duvall, T. L., Jr.;

Astronomical calibration of Gauss to Matuyama sapropels in the Mediterranean and implication for the Geomagnetic Polarity Time Scale

Science.gov (United States)

Hilgen, F. J.

1991-06-01

The astronomically calibrated age of the Olduvai Subchron is established by correlating the cyclic sapropel patterns in the Vrica section and in the sections of Semaforo (Italy), Singa (Italy), Punta Piccola (Sicily), and Francocastello (Crete) to the new astronomical solutions for the precession of the equinox and eccentricity of the earth's orbit, using inferred phase relationships between the sapropel cycles and orbital cycles. The resultant ages for the Olduvai and for older boundaries are then compared with conventional, as well as other orbitally tuned ages, for these polarity transitions. It is shown that this astronomically calibrated time scale can be extended back to the Miocene/Pliocene boundary.

IOT Overview: IR Instruments

Science.gov (United States)

Mason, E.

In this instrument review chapter the calibration plans of ESO IR instruments are presented and briefly reviewed focusing, in particular, on the case of ISAAC, which has been the first IR instrument at VLT and whose calibration plan served as prototype for the coming instruments.

DETECTING CHANGING POLARIZATION STRUCTURES IN SAGITTARIUS A* WITH HIGH FREQUENCY VLBI

International Nuclear Information System (INIS)

Fish, Vincent L.; Doeleman, Sheperd S.; Rogers, Alan E. E.; Broderick, Avery E.; Loeb, Abraham

2009-01-01

Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A* exhibits time-variable linear polarization on timescales corresponding to 6 M sun black hole. In previous work, we demonstrated the potential for total-intensity (sub)millimeter-wavelength very long baseline interferometry (VLBI) to detect time-variable-and periodic-source structure changes in the Sgr A* black hole system using nonimaging analyses. Here, we extend this work to include full polarimetric VLBI observations. We simulate full-polarization (sub)millimeter VLBI data of Sgr A* using a hot spot model that is embedded within an accretion disk, with emphasis on nonimaging polarimetric data products that are robust against calibration errors. Although the source-integrated linear polarization fraction in the models is typically only a few percent, the linear polarization fraction on small angular scales can be much higher, enabling the detection of changes in the polarimetric structure of Sgr A* on a wide variety of baselines. The shortest baselines track the source-integrated linear polarization fraction, while longer baselines are sensitive to polarization substructures that are beam-diluted by connected-element interferometry. The detection of periodic variability in source polarization should not be significantly affected even if instrumental polarization terms cannot be calibrated out. As more antennas are included in the (sub)millimeter-VLBI array, observations with full polarization will provide important new diagnostics to help disentangle intrinsic source polarization from Faraday rotation effects in the accretion and outflow region close to the black hole event horizon.

DETECTING CHANGING POLARIZATION STRUCTURES IN SAGITTARIUS A* WITH HIGH FREQUENCY VLBI

Energy Technology Data Exchange (ETDEWEB)

Fish, Vincent L; Doeleman, Sheperd S; Rogers, Alan E. E. [Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States); Broderick, Avery E [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Loeb, Abraham [Institute for Theory and Computation, Harvard University, Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2009-12-01

Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A* exhibits time-variable linear polarization on timescales corresponding to <10 Schwarzschild radii of the presumed 4 x 10{sup 6} M {sub sun} black hole. In previous work, we demonstrated the potential for total-intensity (sub)millimeter-wavelength very long baseline interferometry (VLBI) to detect time-variable-and periodic-source structure changes in the Sgr A* black hole system using nonimaging analyses. Here, we extend this work to include full polarimetric VLBI observations. We simulate full-polarization (sub)millimeter VLBI data of Sgr A* using a hot spot model that is embedded within an accretion disk, with emphasis on nonimaging polarimetric data products that are robust against calibration errors. Although the source-integrated linear polarization fraction in the models is typically only a few percent, the linear polarization fraction on small angular scales can be much higher, enabling the detection of changes in the polarimetric structure of Sgr A* on a wide variety of baselines. The shortest baselines track the source-integrated linear polarization fraction, while longer baselines are sensitive to polarization substructures that are beam-diluted by connected-element interferometry. The detection of periodic variability in source polarization should not be significantly affected even if instrumental polarization terms cannot be calibrated out. As more antennas are included in the (sub)millimeter-VLBI array, observations with full polarization will provide important new diagnostics to help disentangle intrinsic source polarization from Faraday rotation effects in the accretion and outflow region close to the black hole event horizon.

CERES Top-of-Atmosphere Earth Radiation Budget Climate Data Record: Accounting for in-Orbit Changes in Instrument Calibration

Directory of Open Access Journals (Sweden)

Norman G. Loeb

2016-02-01

Full Text Available The Clouds and the Earth’s Radiant Energy System (CERES project provides observations of Earth’s radiation budget using measurements from CERES instruments onboard the Terra, Aqua and Suomi National Polar-orbiting Partnership (S-NPP satellites. As the objective is to create a long-term climate data record, it is necessary to periodically reprocess the data in order to incorporate the latest calibration changes and algorithm improvements. Here, we focus on the improvements and validation of CERES Terra and Aqua radiances in Edition 4, which are used to generate higher-level climate data products. Onboard sources indicate that the total (TOT channel response to longwave (LW radiation has increased relative to the start of the missions by 0.4% to 1%. In the shortwave (SW, the sensor response change ranges from −0.4% to 0.6%. To account for in-orbit changes in SW spectral response function (SRF, direct nadir radiance comparisons between instrument pairs on the same satellite are made and an improved wavelength dependent degradation model is used to adjust the SRF of the instrument operating in a rotating azimuth plane scan mode. After applying SRF corrections independently to CERES Terra and Aqua, monthly variations amongst these instruments are highly correlated and the standard deviation in the difference of monthly anomalies is 0.2 Wm−2 for ocean and 0.3 Wm−2 for land/desert. Additionally, trends in CERES Terra and Aqua monthly anomalies are consistent to 0.21 Wm−2 per decade for ocean and 0.31 Wm−2 per decade for land/desert. In the LW, adjustments to the TOT channel SRF are made to ensure that removal of the contribution from the SW portion of the TOT channel with SW channel radiance measurements during daytime is consistent throughout the mission. Accordingly, anomalies in day–night LW difference in Edition 4 are more consistent compared to Edition 3, particularly for the Aqua land/desert case.

Spitzer/JWST Cross Calibration: IRAC Observations of Potential Calibrators for JWST

Science.gov (United States)

Carey, Sean J.; Gordon, Karl D.; Lowrance, Patrick; Ingalls, James G.; Glaccum, William J.; Grillmair, Carl J.; E Krick, Jessica; Laine, Seppo J.; Fazio, Giovanni G.; Hora, Joseph L.; Bohlin, Ralph

2017-06-01

We present observations at 3.6 and 4.5 microns using IRAC on the Spitzer Space Telescope of a set of main sequence A stars and white dwarfs that are potential calibrators across the JWST instrument suite. The stars range from brightnesses of 4.4 to 15 mag in K band. The calibration observations use a similar redundancy to the observing strategy for the IRAC primary calibrators (Reach et al. 2005) and the photometry is obtained using identical methods and instrumental photometric corrections as those applied to the IRAC primary calibrators (Carey et al. 2009). The resulting photometry is then compared to the predictions based on spectra from the CALSPEC Calibration Database (http://www.stsci.edu/hst/observatory/crds/calspec.html) and the IRAC bandpasses. These observations are part of an ongoing collaboration between IPAC and STScI investigating absolute calibration in the infrared.

Planck intermediate results: XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth

DEFF Research Database (Denmark)

Aghanim, N.; Ashdown, M.; Aumont, J.

2016-01-01

This paper describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete end-to-end simulat...

PAU/RAD: Design and Preliminary Calibration Results of a New L-Band Pseudo-Correlation Radiometer Concept

Directory of Open Access Journals (Sweden)

Enric Valencia

2008-07-01

Full Text Available The Passive Advanced Unit (PAU for ocean monitoring is a new type of instrument that combines in a single receiver and without time multiplexing, a polarimetric pseudo-correlation microwave radiometer at L-band (PAU-RAD and a GPS reflectometer (PAU-GNSS/R. These instruments in conjunction with an infra-red radiometer (PAU-IR will respectively provide the sea surface temperature and the sea state information needed to accurately retrieve the sea surface salinity from the radiometric measurements. PAU will consist of an array of 4x4 receivers performing digital beamforming and polarization synthesis both for PAU-RAD and PAU-GNSS/R. A concept demonstrator of the PAU instrument with only one receiver has been implemented (PAU-One Receiver or PAU-OR. PAU-OR has been used to test and tune the calibration algorithms that will be applied to PAU. This work describes in detail PAU-OR’s radiometer calibration algorithms and their performance.

On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement

Energy Technology Data Exchange (ETDEWEB)

Kristie Cooper; Gary Pickrell; Anbo Wang

2005-11-01

This report summarizes technical progress April-September 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report. The sensing system will be installed and tested at TECO's Polk Power Station. Following a site visit in June 2005, our efforts have been focused on preparing for that field test, including he design of the sensor mechanical packaging, sensor electronics, the data transfer module, and the necessary software codes to accommodate this application.. We are currently ready to start sensor fabrication.

Interferometric 30 m bench for calibrations of 1D scales and optical distance measuring instruments

International Nuclear Information System (INIS)

Unkuri, J; Rantanen, A; Manninen, J; Esala, V-P; Lassila, A

2012-01-01

During construction of a new metrology building for MIKES, a 30 m interferometric bench was designed. The objective was to implement a straight, stable, adjustable and multifunctional 30 m measuring bench for calibrations. Special attention was paid to eliminating the effects of thermal expansion and inevitable concrete shrinkage. The linear guide, situated on top of a monolithic concrete beam, comprises two parallel round shafts with adjustable fixtures every 1 m. A carriage is moved along the rail and its position is followed by a reference interferometer. Depending on the measurement task, one or two retro-reflectors are fixed on the carriage. A microscope with a CCD camera and a monitor can be used to detect line mark positions on different line standards. When calibrating optical distance measuring instruments, various targets can be fixed to the carriage. For the most accurate measurements an online Abbe-error correction based on simultaneous carriage pitch measurement by a separate laser interferometer is applied. The bench is used for calibrations of machinist scales, tapes, circometers, electronic distance meters, total stations and laser trackers. The estimated expanded uncertainty for 30 m displacement for highest accuracy calibrations is 2.6 µm. (paper)

Calibration and intercomparison methods of dose calibrators used in nuclear medicine facilities

International Nuclear Information System (INIS)

Costa, Alessandro Martins da

1999-01-01

Dose calibrators are used in most of the nuclear medicine facilities to determine the amount of radioactivity administered to a patient in a particular investigation or therapeutic procedure. It is therefore of vital importance that the equipment used presents good performance and is regular;y calibrated at a authorized laboratory. This occurs of adequate quality assurance procedures are carried out. Such quality control tests should be performed daily, other biannually or yearly, testing, for example, its accuracy and precision, the reproducibility and response linearity. In this work a commercial dose calibrator was calibrated with solution of radionuclides used in nuclear medicine. Simple instrument tests, such as response linearity and the response variation of the source volume increase at a constant source activity concentration, were performed. This instrument can now be used as a working standard for calibration of other dose calibrators/ An intercomparison procedure was proposed as a method of quality control of dose calibrators used in nuclear medicine facilities. (author)

American West Tephras – Geomagnetic polarity events redefined through calibration of radio-isotopic and astronomical time

DEFF Research Database (Denmark)

Rivera, Tiffany; Storey, Michael

calibration. Although this geomagnetic event is not part of the most recent geologic timescale, refined ages on short-lived excursions could hold importance to understanding time scales for the wavering nature of Earth’s magnetic field. We propose a new 40Ar/39Ar age for the Quaternary mineral dating standard......The foundation of the EARTHTIME/GTSnext initiative seeks to construct an internally consistent geologic timescale based on astronomical and radio-isotopic geochronology. American west tephras offer a prime opportunity to integrate these two independent timescales with the geomagnetic timescale....... Using an astronomically calibrated age for the monitor mineral Fish Canyon sanidine (FCs;28.201 ± 0.046 Ma, Kuiper, et al., 2008), ages of Pleistocene geomagnetic polarity events are reexamined. Of particular interest, the Quaternary mineral dating standard Alder Creek sandine (ACs) is the type locality...

Calibration results using highly aberrated images for aligning the JWST instruments to the telescope

Science.gov (United States)

Smith, Koby Z.; Acton, D. Scott; Gallagher, Ben B.; Knight, J. Scott; Dean, Bruce H.; Jurling, Alden S.; Zielinski, Thomas P.

2016-07-01

mostly of 3rd-order astigmatism and coma. This is because the elliptical tertiary mirror of the AOS is used off of its ideal foci locations without the compensating wavefront effects of the JWST primary and secondary mirrors. Therefore, the PSFs created are highly asymmetric with relatively complex structure and the centroid and encircled energy analyses traditionally used to locate images are not sufficient for ensuring the AOS to ISIM alignment. A novel approach combining phase retrieval and spatial metrology was developed to both locate the images with respect to the AOS and provide calibration information for eventual AOS to ISIM alignment verification. During final JWST OTE and ISIM (OTIS) testing, only a single thru-focus image will be collected by the instruments. Therefore, tools and processes were developed to perform single-image phase retrieval on these highly aberrated images such that any single image of the ASPA source can provide calibrated knowledge of the instruments' position relative to the AOS. This paper discusses the results of the methodology, hardware, and calibration performed to ensure that the AOS and ISIM are aligned within their respective tolerances at JWST OTIS testing.

Calibration procedure and wavelength correction for neutron depolarization experiments

International Nuclear Information System (INIS)

Roest, W.; Rekveldt, M.T.

1992-01-01

The neutron polarimeter, for which an extended calibration procedure is described here, enables one to investigate magnetic properties of materials. Such an investigation is carried out by offering a polarized neutron beam in the x-, y- and z-direction successively and, after transmission through the sample, by analysing the polarization in all three directions. The result is a 3x3 depolarization matrix. After the polarizer, the neutron beam has a polarization along the z-direction. Two coil systems creating a magnetic field in the yz-plane perpendicular to the beam direction provide the possibility to direct the polarization in the x-, y- and z-direction by means of Larmor precession of the polarization in these fields. New research areas, where small depolarization effects together with considerable polarization rotation are measured, have caused a need for more accuracy in, and better knowledge of the calibration of the polarimeter. The calibration procedure use up to now and the improvements made on it are described. (orig.)

Calibration guidelines for surface texture instruments - horizontal axis

DEFF Research Database (Denmark)

Andreasen, Jan Lasson; Shem, R. Krüger

The present report is a documentation of the work carried out at DTU, on TASK 5.1: PROCEDURES FOR CALIBRATION IN X- AND Y- DIRECTION the project with contract SMT4-CT97-2176 with title: Calibration Standards for Surface Topography Measuring Systems down to Nanometric Scale. After a short introduc......The present report is a documentation of the work carried out at DTU, on TASK 5.1: PROCEDURES FOR CALIBRATION IN X- AND Y- DIRECTION the project with contract SMT4-CT97-2176 with title: Calibration Standards for Surface Topography Measuring Systems down to Nanometric Scale. After a short...

Sandia WIPP calibration traceability

Energy Technology Data Exchange (ETDEWEB)

Schuhen, M.D. [Sandia National Labs., Albuquerque, NM (United States); Dean, T.A. [RE/SPEC, Inc., Albuquerque, NM (United States)

1996-05-01

This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities.

Sandia WIPP calibration traceability

International Nuclear Information System (INIS)

Schuhen, M.D.; Dean, T.A.

1996-05-01

This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities

FTIR Calibration Methods and Issues

Science.gov (United States)

Perron, Gaetan

Over the past 10 years, several space-borne FTIR missions were launched for atmospheric research, environmental monitoring and meteorology. One can think of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) launched by the European Space Agency, the Atmospheric Chemistry Experiment (ACE) launched by the Canadian Space Agency, the Tropospheric Emission Spectrometer (TES) launched by NASA and the Infrared Atmospheric Sounding Interferometer (IASI) launched by Eumetsat in Europe. Others are near to be launched, namely the Cross-track Infrared Sounder (CrIS) from the Integrated Program Of- fice in the United States and the Thermal And Near infrared Sensor for carbon Observation (TANSO) from the Japan Aerospace Exploration Agency. Moreover, several missions under definition foresee the use of this technology as sensor, e.g. Meteosat Third Generation (MTG), Eumetsat Polar System (EPS) and the Premier mission, one of the six candidates of the next ESA Earth Explorer Core Mission. In order to produce good quality products, calibration is essential. Calibrated data is the output of three main sub-systems that are tightly coupled: the instrument, the calibration targets and the level 1B processor. Calibration requirements must be carefully defined and propagated to each sub-system. Often, they are carried out by different parties which add to the complexity. Under budget and schedule pressure, some aspects are sometimes neglected and jeopardized final quality. For space-borne FTIR, level 1B outputs are spectra that are radiometrically, spectrally calibrated and geolocated. Radiometric calibration means to assign an intensity value in units to the y-axis. Spectral calibration means to assign to the x-axis the proper frequency value in units. Finally, geolocated means to assign a target position over the earth geoid i.e. longitude, latitude and altitude. This paper will present calibration methods and issues related to space-borne FTIR missions, e.g. two

In-flight calibration of the spin axis offset of a fluxgate magnetometer with an electron drift instrument

Science.gov (United States)

Leinweber, H. K.; Russell, C. T.; Torkar, K.

2012-10-01

We show that the spin axis offset of a fluxgate magnetometer can be calibrated with an electron drift instrument (EDI) and that the required input time interval is relatively short. For missions such as Cluster or the upcoming Magnetospheric Multiscale (MMS) mission the spin axis offset of a fluxgate magnetometer could be determined on an orbital basis. An improvement of existing methods for finding spin axis offsets via comparison of accurate measurements of the field magnitude is presented, that additionally matches the gains of the two instruments that are being compared. The technique has been applied to EDI data from the Cluster Active Archive and fluxgate magnetometer data processed with calibration files also from the Cluster Active Archive. The method could prove to be valuable for the MMS mission because the four MMS spacecraft will only be inside the interplanetary field (where spin axis offsets can be calculated from Alfvénic fluctuations) for short periods of time and during unusual solar wind conditions.

In-flight calibration of the spin axis offset of a fluxgate magnetometer with an electron drift instrument

International Nuclear Information System (INIS)

Leinweber, H K; Russell, C T; Torkar, K

2012-01-01

We show that the spin axis offset of a fluxgate magnetometer can be calibrated with an electron drift instrument (EDI) and that the required input time interval is relatively short. For missions such as Cluster or the upcoming Magnetospheric Multiscale (MMS) mission the spin axis offset of a fluxgate magnetometer could be determined on an orbital basis. An improvement of existing methods for finding spin axis offsets via comparison of accurate measurements of the field magnitude is presented, that additionally matches the gains of the two instruments that are being compared. The technique has been applied to EDI data from the Cluster Active Archive and fluxgate magnetometer data processed with calibration files also from the Cluster Active Archive. The method could prove to be valuable for the MMS mission because the four MMS spacecraft will only be inside the interplanetary field (where spin axis offsets can be calculated from Alfvénic fluctuations) for short periods of time and during unusual solar wind conditions. (paper)

Overview of intercalibration of satellite instruments

Science.gov (United States)

Chander, G.; Hewison, T.J.; Fox, N.; Wu, X.; Xiong, X.; Blackwell, W.J.

2013-01-01

Inter-calibration of satellite instruments is critical for detection and quantification of changes in the Earth’s environment, weather forecasting, understanding climate processes, and monitoring climate and land cover change. These applications use data from many satellites; for the data to be inter-operable, the instruments must be cross-calibrated. To meet the stringent needs of such applications requires that instruments provide reliable, accurate, and consistent measurements over time. Robust techniques are required to ensure that observations from different instruments can be normalized to a common scale that the community agrees on. The long-term reliability of this process needs to be sustained in accordance with established reference standards and best practices. Furthermore, establishing physical meaning to the information through robust Système International d'unités (SI) traceable Calibration and Validation (Cal/Val) is essential to fully understand the parameters under observation. The processes of calibration, correction, stability monitoring, and quality assurance need to be underpinned and evidenced by comparison with “peer instruments” and, ideally, highly calibrated in-orbit reference instruments. Inter-calibration between instruments is a central pillar of the Cal/Val strategies of many national and international satellite remote sensing organizations. Inter-calibration techniques as outlined in this paper not only provide a practical means of identifying and correcting relative biases in radiometric calibration between instruments but also enable potential data gaps between measurement records in a critical time series to be bridged. Use of a robust set of internationally agreed upon and coordinated inter-calibration techniques will lead to significant improvement in the consistency between satellite instruments and facilitate accurate monitoring of the Earth’s climate at uncertainty levels needed to detect and attribute the mechanisms

Polarized neutrons

International Nuclear Information System (INIS)

Williams, W.G.

1988-01-01

The book on 'polarized neutrons' is intended to inform researchers in condensed matter physics and chemistry of the diversity of scientific problems that can be investigated using polarized neutron beams. The contents include chapters on:- neutron polarizers and instrumentation, polarized neutron scattering, neutron polarization analysis experiments and precessing neutron polarization. (U.K.)

First results of Chinese particle instruments in the Double Star Program

Directory of Open Access Journals (Sweden)

J. B. Cao

2005-11-01

Full Text Available Double Star Program (DSP aims to investigate the trigger mechanism and physical models of geomagnetic storms and substorms. The DSP involves two satellites: the equatorial satellite of DSP (TC-1 in China and the polar satellite of DSP (TC-2 in China. On board the two satellites of TC-1 and TC-2, there are four kinds of particle instruments developed by the Center for Space Science and Applied Research (CSSAR, namely: the High Energy Electron Detector (HEED, TC-1, 2, the High Energy Proton Detector (HEPD, TC-1, 2, the High Energy Heavy Ion Detector (HID, TC-1, 2 and the Low Energy Ion Detector (LEID, TC-2. HEED, HEPD and HID were developed and calibrated in China. The LEID was developed in China and calibrated in France. This paper introduces the scientific objectives and characteristics of each instrument, their status and some preliminary results.

Astrobiology Sample Analysis Program (ASAP) for Advanced Life Detection Instrumentation Development and Calibration

Science.gov (United States)

Glavin, Daniel; Brinkerhoff, Will; Dworkin, Jason; Eigenbrode, Jennifer; Franz, Heather; Mahaffy, Paul; Stern, Jen; Blake, Daid; Sandford, Scott; Fries, marc;

Verification of the Indicating Measuring Instruments Taking into Account their Instrumental Measurement Uncertainty

Directory of Open Access Journals (Sweden)

Zakharov Igor

2017-12-01

Full Text Available The specific features of the measuring instruments verification based on the results of their calibration are considered. It is noted that, in contrast to the verification procedure used in the legal metrology, the verification procedure for calibrated measuring instruments has to take into account the uncertainty of measurements into account. In this regard, a large number of measuring instruments, considered as those that are in compliance after verification in the legal metrology, turns out to be not in compliance after calibration. In this case, it is necessary to evaluate the probability of compliance of indicating measuring instruments. The procedure of compliance probability determination on the basis of the Monte Carlo method is considered. An example of calibration of a Vernier caliper is given.

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.

UAVSAR Program: Initial Results from New Instrument Capabilities

Science.gov (United States)

Lou, Yunling; Hensley, Scott; Moghaddam, Mahta; Moller, Delwyn; Chapin, Elaine; Chau, Alexandra; Clark, Duane; Hawkins, Brian; Jones, Cathleen; Marks, Phillip;

Digibaro pressure instrument onboard the Phoenix Lander

Science.gov (United States)

Harri, A.-M.; Polkko, J.; Kahanpää, H. H.; Schmidt, W.; Genzer, M. M.; Haukka, H.; Savijarv1, H.; Kauhanen, J.

2009-04-01

The Phoenix Lander landed successfully on the Martian northern polar region. The mission is part of the National Aeronautics and Space Administration's (NASA's) Scout program. Pressure observations onboard the Phoenix lander were performed by an FMI (Finnish Meteorological Institute) instrument, based on a silicon diaphragm sensor head manufactured by Vaisala Inc., combined with MDA data processing electronics. The pressure instrument performed successfully throughout the Phoenix mission. The pressure instrument had 3 pressure sensor heads. One of these was the primary sensor head and the other two were used for monitoring the condition of the primary sensor head during the mission. During the mission the primary sensor was read with a sampling interval of 2 s and the other two were read less frequently as a check of instrument health. The pressure sensor system had a real-time data-processing and calibration algorithm that allowed the removal of temperature dependent calibration effects. In the same manner as the temperature sensor, a total of 256 data records (8.53 min) were buffered and they could either be stored at full resolution, or processed to provide mean, standard deviation, maximum and minimum values for storage on the Phoenix Lander's Meteorological (MET) unit.The time constant was approximately 3s due to locational constraints and dust filtering requirements. Using algorithms compensating for the time constant effect the temporal resolution was good enough to detect pressure drops associated with the passage of nearby dust devils.

CERN Radiation Protection (RP) calibration facilities

CERN Document Server

AUTHOR|(CDS)2082069; Macián-Juan, Rafael

Radiation protection calibration facilities are essential to ensure the correct operation of radiation protection instrumentation. Calibrations are performed in specific radiation fields according to the type of instrument to be calibrated: neutrons, photons, X-rays, beta and alpha particles. Some of the instruments are also tested in mixed radiation fields as often encountered close to high-energy particle accelerators. Moreover, calibration facilities are of great importance to evaluate the performance of prototype detectors; testing and measuring the response of a prototype detector to well-known and -characterized radiation fields contributes to improving and optimizing its design and capabilities. The CERN Radiation Protection group is in charge of performing the regular calibrations of all CERN radiation protection devices; these include operational and passive dosimeters, neutron and photon survey-meters, and fixed radiation detectors to monitor the ambient dose equivalent, H*(10), inside CERN accelera...

The Fundamentals of the Air Sampler Calibration-Verification Process

International Nuclear Information System (INIS)

Gavila, F.M.

2011-01-01

The calibration of an air sampling instrument using a reference air flow calibrator requires attention to scientific detail in order to establish that the instrument's reported values are correctly stated and valid under the actual operating conditions of the air sampling instrument. The primary objective of an air flow calibration-verification is to ensure that the device under test (DUT) is within the manufacturer's stated accuracy range of temperature, pressure and humidity conditions under which the instrument was designed to operate. The DUT output values are compared to those obtained from a reference instrument (REF) measuring the sample physical parameter that the DUT is measuring. An accurate comparison of air flow rates or air volumes requires that the comparison of the DUT and REF values be made under the same temperature and pressure conditions. It is absolutely necessary that the REF be more accurate than the DUT; otherwise, it can not be considered a reference instrument. The REF should be at least twice as accurate and, if possible, it should be four times as accurate as the DUT. Upon confirmation that the DUT meets the manufacturer's accuracy criteria, the technician must place a calibration sticker or label indicating the date of calibration, the expiration date of the calibration and an authorized signature. If it is a limited-use instrument, the label should state the limited-use operating range. The serial number and model number of the instrument should also be shown on the calibration sticker. A specific calibration file for each instrument by serial number should be kept in the calibration laboratory file records. Instruments that display gas flow or gas volume values corrected to a reference temperature and pressure are very desirable. The ideal situation is when both the DUT and the REF output flow rate or volume values are at the same conditions of T and P. The calibration-verification is, then, a simple process. The credibility of an air

Medicina array demonstrator: calibration and radiation pattern characterization using a UAV-mounted radio-frequency source

Science.gov (United States)

Pupillo, G.; Naldi, G.; Bianchi, G.; Mattana, A.; Monari, J.; Perini, F.; Poloni, M.; Schiaffino, M.; Bolli, P.; Lingua, A.; Aicardi, I.; Bendea, H.; Maschio, P.; Piras, M.; Virone, G.; Paonessa, F.; Farooqui, Z.; Tibaldi, A.; Addamo, G.; Peverini, O. A.; Tascone, R.; Wijnholds, S. J.

2015-06-01

One of the most challenging aspects of the new-generation Low-Frequency Aperture Array (LFAA) radio telescopes is instrument calibration. The operational LOw-Frequency ARray (LOFAR) instrument and the future LFAA element of the Square Kilometre Array (SKA) require advanced calibration techniques to reach the expected outstanding performance. In this framework, a small array, called Medicina Array Demonstrator (MAD), has been designed and installed in Italy to provide a test bench for antenna characterization and calibration techniques based on a flying artificial test source. A radio-frequency tone is transmitted through a dipole antenna mounted on a micro Unmanned Aerial Vehicle (UAV) (hexacopter) and received by each element of the array. A modern digital FPGA-based back-end is responsible for both data-acquisition and data-reduction. A simple amplitude and phase equalization algorithm is exploited for array calibration owing to the high stability and accuracy of the developed artificial test source. Both the measured embedded element patterns and calibrated array patterns are found to be in good agreement with the simulated data. The successful measurement campaign has demonstrated that a UAV-mounted test source provides a means to accurately validate and calibrate the full-polarized response of an antenna/array in operating conditions, including consequently effects like mutual coupling between the array elements and contribution of the environment to the antenna patterns. A similar system can therefore find a future application in the SKA-LFAA context.

PLEIADES ABSOLUTE CALIBRATION : INFLIGHT CALIBRATION SITES AND METHODOLOGY

Directory of Open Access Journals (Sweden)

S. Lachérade

2012-07-01

Full Text Available In-flight calibration of space sensors once in orbit is a decisive step to be able to fulfil the mission objectives. This article presents the methods of the in-flight absolute calibration processed during the commissioning phase. Four In-flight calibration methods are used: absolute calibration, cross-calibration with reference sensors such as PARASOL or MERIS, multi-temporal monitoring and inter-bands calibration. These algorithms are based on acquisitions over natural targets such as African deserts, Antarctic sites, La Crau (Automatic calibration station and Oceans (Calibration over molecular scattering or also new extra-terrestrial sites such as the Moon and selected stars. After an overview of the instrument and a description of the calibration sites, it is pointed out how each method is able to address one or several aspects of the calibration. We focus on how these methods complete each other in their operational use, and how they help building a coherent set of information that addresses all aspects of in-orbit calibration. Finally, we present the perspectives that the high level of agility of PLEIADES offers for the improvement of its calibration and a better characterization of the calibration sites.

The status of the QUIJOTE multi-frequency instrument

Science.gov (United States)

Hoyland, R. J.; Aguiar-González, M.; Aja, B.; Ariño, J.; Artal, E.; Barreiro, R. B.; Blackhurst, E. J.; Cagigas, J.; Cano de Diego, J. L.; Casas, F. J.; Davis, R. J.; Dickinson, C.; Arriaga, B. E.; Fernandez-Cobos, R.; de la Fuente, L.; Génova-Santos, R.; Gómez, A.; Gomez, C.; Gómez-Reñasco, F.; Grainge, K.; Harper, S.; Herran, D.; Herreros, J. M.; Herrera, G. A.; Hobson, M. P.; Lasenby, A. N.; Lopez-Caniego, M.; López-Caraballo, C.; Maffei, B.; Martinez-Gonzalez, E.; McCulloch, M.; Melhuish, S.; Mediavilla, A.; Murga, G.; Ortiz, D.; Piccirillo, L.; Pisano, G.; Rebolo-López, R.; Rubiño-Martin, J. A.; Ruiz, J. Luis; Sanchez de la Rosa, V.; Sanquirce, R.; Vega-Moreno, A.; Vielva, P.; Viera-Curbelo, T.; Villa, E.; Vizcargüenaga, A.; Watson, R. A.

2012-09-01

The QUIJOTE-CMB project has been described in previous publications. Here we present the current status of the QUIJOTE multi-frequency instrument (MFI) with five separate polarimeters (providing 5 independent sky pixels): two which operate at 10-14 GHz, two which operate at 16-20 GHz, and a central polarimeter at 30 GHz. The optical arrangement includes 5 conical corrugated feedhorns staring into a dual reflector crossed-draconian system, which provides optimal cross-polarization properties (designed to be switch out various systematics. The detection system provides optimum sensitivity through 2 correlated and 2 total power channels. The system is calibrated using bright polarized celestial sources and through a secondary calibration source and antenna. The acquisition system, telescope control and housekeeping are all linked through a real-time gigabit Ethernet network. All communication, power and helium gas are passed through a central rotary joint. The time stamp is synchronized to a GPS time signal. The acquisition software is based on PLCs written in Beckhoffs TwinCat and ethercat. The user interface is written in LABVIEW. The status of the QUIJOTE MFI will be presented including pre-commissioning results and laboratory testing.

Validation of a densimeter calibration procedure for a secondary calibration laboratory

International Nuclear Information System (INIS)

Alpizar Herrera, Juan Carlos

2014-01-01

A survey was conducted to quantify the need for calibration of a density measurement instrument at the research units at the Sede Rodrigo Facio of the Universidad de Costa Rica. A calibration procedure was documented for the instrument that presented the highest demand in the survey by the calibration service. A study of INTE-ISO/IEC 17025: 2005 and specifically in section 5.4 of this standard was done, to document the procedure for calibrating densimeters. Densimeter calibration procedures and standards were sought from different national and international sources. The method of hydrostatic weighing or Cuckow method was the basis of the defined procedure. Documenting the calibration procedure and creating other documents was performed for data acquisition log, intermediate calculation log and calibration certificate copy. A veracity test was performed using as reference laboratory a laboratory of calibration secondary national as part of the validation process of the documented procedure. The results of the E_n statistic of 0.41; 0.34 and 0.46 for the calibration points 90%, 50% and 10% were obtained for the densimeter scale respectively. A reproducibility analysis of the method was performed with satisfactory results. Different suppliers were contacted to estimate the economic costs of the equipment and materials, needed to develop the documented method of densimeter calibration. The acquisition of an analytical balance was recommended, instead of a precision scale, in order to improve the results obtained with the documented method [es

Calibration and field evaluation of polar organic chemical integrative sampler (POCIS) for monitoring pharmaceuticals in hospital wastewater

International Nuclear Information System (INIS)

Bailly, Emilie; Levi, Yves; Karolak, Sara

2013-01-01

The Polar Organic Chemical Integrative Sampler (POCIS) is a new tool for the sampling of organic pollutants in water. We tested this device for the monitoring of pharmaceuticals in hospital wastewater. After calibration, a field application was carried out in a French hospital for six pharmaceutical compounds (Atenolol, Prednisolone, Methylprednisolone, Sulfamethoxazole, Ofloxacin, Ketoprofen). POCIS were calibrated in tap water and wastewater in laboratory conditions close to relevant environmental conditions (temperature, flow velocity). Sampling rates (R s ) were determined and we observed a significant increase with flow velocity and temperature. Whatever the compound, the R s value was lower in wastewater and the linear phase of uptake was shorter. POCIS were deployed in a hospital sewage pipe during four days and the estimated water concentrations were close to those obtained with twenty-four hour composite samples. -- Highlights: ► Calibration of POCIS for the monitoring of pharmaceuticals in hospital wastewater. ► Uptake profile presents a shorter linear phase in wastewater than in tap water. ► Influence of R s values by temperature, flow velocity and bio-fouling. ► Correlation between concentrations estimated from POCIS or measured in TWA samples. ► Deployment period should be no longer than five days. -- After calibration in tap water and hospital wastewater, POCIS were used to monitor pharmaceuticals in hospital sewage and were compared to TWA sampling

Monochromatic Measurements of the JPSS-1 VIIRS Polarization Sensitivity

Science.gov (United States)

McIntire, Jeff; Moyer, David; Brown, Steven W.; Lykke, Keith R.; Waluschka, Eugene; Oudrari, Hassan; Xiong, Xiaoxiong

2016-01-01

Polarization sensitivity is a critical property that must be characterized for spaceborne remote sensing instruments designed to measure reflected solar radiation. Broadband testing of the first Joint Polar-orbiting Satellite System (JPSS-1) Visible Infrared Imaging Radiometer Suite (VIIRS) showed unexpectedly large polarization sensitivities for the bluest bands on VIIRS (centered between 400 and 600 nm). Subsequent ray trace modeling indicated that large diattenuation on the edges of the bandpass for these spectral bands was the driver behind these large sensitivities. Additional testing using the National Institute of Standards and Technologies Traveling Spectral Irradiance and Radiance Responsivity Calibrations Using Uniform Sources was added to the test program to verify and enhance the model. The testing was limited in scope to two spectral bands at two scan angles; nonetheless, this additional testing provided valuable insight into the polarization sensitivity. Analysis has shown that the derived diattenuation agreed with the broadband measurements to within an absolute difference of about0.4 and that the ray trace model reproduced the general features of the measured data. Additionally, by deriving the spectral responsivity, the linear diattenuation is shown to be explicitly dependent on the changes in bandwidth with polarization state.

Information management for maintenance of instrument calibration data

International Nuclear Information System (INIS)

Tam, Y.

1995-01-01

This paper discusses the rationale for developing a calibration information system at Ontario Hydro Pickering Nuclear Division (PND), including the approach to calibration information problems, the identification of existing processes, discovery of alternatives, selection of the best alternative and project development. (author)

Calibrate the aerial surveying instrument by the limited surface source and the single point source that replace the unlimited surface source

CERN Document Server

Lu Cun Heng

1999-01-01

It is described that the calculating formula and surveying result is found on the basis of the stacking principle of gamma ray and the feature of hexagonal surface source when the limited surface source replaces the unlimited surface source to calibrate the aerial survey instrument on the ground, and that it is found in the light of the exchanged principle of the gamma ray when the single point source replaces the unlimited surface source to calibrate aerial surveying instrument in the air. Meanwhile through the theoretical analysis, the receiving rate of the crystal bottom and side surfaces is calculated when aerial surveying instrument receives gamma ray. The mathematical expression of the gamma ray decaying following height according to the Jinge function regularity is got. According to this regularity, the absorbing coefficient that air absorbs the gamma ray and the detective efficiency coefficient of the crystal is calculated based on the ground and air measuring value of the bottom surface receiving cou...

NIST display colorimeter calibration facility

Science.gov (United States)

Brown, Steven W.; Ohno, Yoshihiro

2003-07-01

A facility has been developed at the National Institute of Standards and Technology (NIST) to provide calibration services for color-measuring instruments to address the need for improving and certifying the measurement uncertainties of this type of instrument. While NIST has active programs in photometry, flat panel display metrology, and color and appearance measurements, these are the first services offered by NIST tailored to color-measuring instruments for displays. An overview of the facility, the calibration approach, and associated uncertainties are presented. Details of a new tunable colorimetric source and the development of new transfer standard instruments are discussed.

LabVIEW-based control software for para-hydrogen induced polarization instrumentation.

Science.gov (United States)

Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

2014-04-01

The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10,000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ((13)C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (Bo), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of (13)C based endogenous contrast agents used in molecular imaging.

LabVIEW-based control software for para-hydrogen induced polarization instrumentation

International Nuclear Information System (INIS)

Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

2014-01-01

The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10 000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ( 13 C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (B o ), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of 13 C based endogenous contrast agents used in molecular imaging

In-situ Calibration of Ground -based Lidar instrument

DEFF Research Database (Denmark)

Georgieva Yankova, Ginka; Villanueva, Héctor

This report presents the result of the lidar in-situ calibration performed at DTU’s test site for large wind turbine at Østerild, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertainties provided by mea...

Guidelines on calibration of neutron measuring devices

International Nuclear Information System (INIS)

Burger, G.

1988-01-01

The International Atomic Energy Agency and the World Health Organization have agreed to establish an IAEA/WHO Network of Secondary Standard Dosimetry Laboratories (SSDLs) in order to improve accuracy in applied radiation dosimetry throughout the world. These SSDLs must be equipped with, and maintain, secondary standard instruments, which have been calibrated against primary standards, and must be nominated by their governments for membership of the network. The majority of the existing SSDLs were established primarily to work with photon radiation (X-rays and gamma rays). Neutron sources are, however, increasingly being applied in industrial processes, research, nuclear power development and radiation biology and medicine. Thus, it is desirable that the SSDLs in countries using neutron sources on a regular basis should also fulfil the minimum requirements to calibrate neutron measuring devices. It is the primary purpose of this handbook to provide guidance on calibration of instruments for radiation protection. A calibration laboratory should also be in a position to calibrate instrumentation being used for the measurement of kerma and absorbed dose and their corresponding rates. This calibration is generally done with photons. In addition, since each neutron field is usually contaminated by photons produced in the source or by scatter in the surrounding media, neutron protection instrumentation has to be tested with respect to its intrinsic photon response. The laboratory will therefore need to possess equipment for photon calibration. This publication deals primarily with methods of applying radioactive neutron sources for calibration of instrumentation, and gives an indication of the space, manpower and facilities needed to fulfil the minimum requirements of a calibration laboratory for neutron work. It is intended to serve as a guide for centres about to start on neutron dosimetry standardization and calibration. 94 refs, 8 figs, 12 tabs

A fully Bayesian method for jointly fitting instrumental calibration and X-ray spectral models

International Nuclear Information System (INIS)

Xu, Jin; Yu, Yaming; Van Dyk, David A.; Kashyap, Vinay L.; Siemiginowska, Aneta; Drake, Jeremy; Ratzlaff, Pete; Connors, Alanna; Meng, Xiao-Li

2014-01-01

Owing to a lack of robust principled methods, systematic instrumental uncertainties have generally been ignored in astrophysical data analysis despite wide recognition of the importance of including them. Ignoring calibration uncertainty can cause bias in the estimation of source model parameters and can lead to underestimation of the variance of these estimates. We previously introduced a pragmatic Bayesian method to address this problem. The method is 'pragmatic' in that it introduced an ad hoc technique that simplified computation by neglecting the potential information in the data for narrowing the uncertainty for the calibration product. Following that work, we use a principal component analysis to efficiently represent the uncertainty of the effective area of an X-ray (or γ-ray) telescope. Here, however, we leverage this representation to enable a principled, fully Bayesian method that coherently accounts for the calibration uncertainty in high-energy spectral analysis. In this setting, the method is compared with standard analysis techniques and the pragmatic Bayesian method. The advantage of the fully Bayesian method is that it allows the data to provide information not only for estimation of the source parameters but also for the calibration product—here the effective area, conditional on the adopted spectral model. In this way, it can yield more accurate and efficient estimates of the source parameters along with valid estimates of their uncertainty. Provided that the source spectrum can be accurately described by a parameterized model, this method allows rigorous inference about the effective area by quantifying which possible curves are most consistent with the data.

A new instrumental set-up for polarized neutron scattering experiments

International Nuclear Information System (INIS)

Schmidt, Wolfgang; Ohl, Michael

2005-01-01

Neutron scattering with polarization analysis is a powerful tool to determine magnetic structures and excitations. A common setup is to mount the sample at the center of a Helmholtz-type coil which can provide a magnetic field of any direction at the sample position and also a guide field along the neutron flight paths around the sample. Recent experiments showed quite a high demand for measurements at low momentum transfers. For the corresponding low scattering angles air scattering gives rise to a very large background. For this reason we have extended the standard setup to a combination of a large vacuum tank surrounded by electrical coils. The vacuum tank eliminates the air scattering and we can use the polarization analysis down to the lowest accessible momentum transfers. The coils themselves also show some new features: In contrary to the classic (symmetric) coil distribution we use an asymmetric setup which gives the advantage of a larger scattering window. Due to a more sophisticated current distribution this modified coil arrangement needs not to be rotated for different scattering conditions. The whole set-up will soon be available at IN12, a cold neutrons three-axis spectrometer operated by FZ Juelich in collaboration with CEA Grenoble as a CRG-B instrument at the Institut Laue Langevin in Grenoble

The extended wedge method: atomic force microscope friction calibration for improved tolerance to instrument misalignments, tip offset, and blunt probes.

Science.gov (United States)

Khare, H S; Burris, D L

2013-05-01

One of the major challenges in understanding and controlling friction is the difficulty in bridging the length and time scales of macroscale contacts and those of the single asperity interactions they comprise. While the atomic force microscope (AFM) offers a unique ability to probe tribological surfaces in a wear-free single-asperity contact, instrument calibration challenges have limited the usefulness of this technique for quantitative nanotribological studies. A number of lateral force calibration techniques have been proposed and used, but none has gained universal acceptance due to practical considerations, configuration limitations, or sensitivities to unknowable error sources. This paper describes a simple extension of the classic wedge method of AFM lateral force calibration which: (1) allows simultaneous calibration and measurement on any substrate, thus eliminating prior tip damage and confounding effects of instrument setup adjustments; (2) is insensitive to adhesion, PSD cross-talk, transducer/piezo-tube axis misalignment, and shear-center offset; (3) is applicable to integrated tips and colloidal probes; and (4) is generally applicable to any reciprocating friction coefficient measurement. The method was applied to AFM measurements of polished carbon (99.999% graphite) and single crystal MoS2 to demonstrate the technique. Carbon and single crystal MoS2 had friction coefficients of μ = 0.20 ± 0.04 and μ = 0.006 ± 0.001, respectively, against an integrated Si probe. Against a glass colloidal sphere, MoS2 had a friction coefficient of μ = 0.005 ± 0.001. Generally, the measurement uncertainties ranged from 10%-20% and were driven by the effect of actual frictional variation on the calibration rather than calibration error itself (i.e., due to misalignment, tip-offset, or probe radius).

Calibration/validation strategy for GOES-R L1b data products

Science.gov (United States)

Fulbright, Jon P.; Kline, Elizabeth; Pogorzala, David; MacKenzie, Wayne; Williams, Ryan; Mozer, Kathryn; Carter, Dawn; Race, Randall; Sims, Jamese; Seybold, Matthew

2016-10-01

The Geostationary Operational Environmental Satellite-R series (GOES-R) will be the next generation of NOAA geostationary environmental satellites. The first satellite in the series is planned for launch in November 2016. The satellite will carry six instruments dedicated to the study of the Earth's weather, lightning mapping, solar observations, and space weather monitoring. Each of the six instruments require specialized calibration plans to achieve their product quality requirements. In this talk we will describe the overall on-orbit calibration program and data product release schedule of the GOES-R program, as well as an overview of the strategies of the individual instrument science teams. The Advanced Baseline Imager (ABI) is the primary Earth-viewing weather imaging instrument on GOES-R. Compared to the present on-orbit GOES imagers, ABI will provide three times the spectral bands, four times the spatial resolution, and operate five times faster. The increased data demands and product requirements necessitate an aggressive and innovative calibration campaign. The Geostationary Lightning Mapper (GLM) will provide continuous rapid lightning detection information covering the Americas and nearby ocean regions. The frequency of lightning activity points to the intensification of storms and may improve tornado warning lead time. The calibration of GLM will involve intercomparisons with ground-based lightning detectors, an airborne field campaign, and a ground-based laser beacon campaign. GOES-R also carries four instruments dedicated to the study of the space environment. The Solar Ultraviolet Imager (SUVI) and the Extreme Ultraviolet and X-Ray Irradiance Sensors (EXIS) will study solar activity that may affect power grids, communication, and spaceflight. The Space Environment In-Situ Suite (SEISS) and the Magnetometer (MAG) study the in-situ space weather environment. These instruments follow a calibration and validation (cal/val) program that relies on

Reactor operations, inspection and maintenance. PNGS Calibration Program

International Nuclear Information System (INIS)

Lopez, E.

1997-01-01

The PNGS Calibration Program is being implemented as a response to various concerns identified in recent PEER evaluations and AECB audits. Identified areas of concern were the approach to instrument calibration of Special Safety Systems (SSS). The implementation of a calibration program is a significant improvement in operating practices. A systematic and comprehensive approach to calibration of instrumentation will improve the quality of operation of the plant with a positive contribution to PNGS safety of operation and economic objectives. This paper describes the strategy to implement the proposed calibration program and describes its calibration data requirements. (DM)

Calibration Laboratory of the Paul Scherrer Institute

International Nuclear Information System (INIS)

Gmuer, K.; Wernli, C.

1994-01-01

Calibration and working checks of radiation protection instruments are carried out at the Calibration Laboratory of the Paul Scherrer Institute. In view of the new radiation protection regulation, the calibration laboratory received an official federal status. The accreditation procedure in cooperation with the Federal Office of Metrology enabled a critical review of the techniques and methods applied. Specifically, personal responsibilities, time intervals for recalibration of standard instruments, maximum permissible errors of verification, traceability and accuracy of the standard instruments, form and content of the certificates were defined, and the traceability of the standards and quality assurance were reconsidered. (orig.) [de

POLCAL - POLARIMETRIC RADAR CALIBRATION

Science.gov (United States)

Vanzyl, J.

1994-01-01

Calibration of polarimetric radar systems is a field of research in which great progress has been made over the last few years. POLCAL (Polarimetric Radar Calibration) is a software tool intended to assist in the calibration of Synthetic Aperture Radar (SAR) systems. In particular, POLCAL calibrates Stokes matrix format data produced as the standard product by the NASA/Jet Propulsion Laboratory (JPL) airborne imaging synthetic aperture radar (AIRSAR). POLCAL was designed to be used in conjunction with data collected by the NASA/JPL AIRSAR system. AIRSAR is a multifrequency (6 cm, 24 cm, and 68 cm wavelength), fully polarimetric SAR system which produces 12 x 12 km imagery at 10 m resolution. AIRSTAR was designed as a testbed for NASA's Spaceborne Imaging Radar program. While the images produced after 1991 are thought to be calibrated (phase calibrated, cross-talk removed, channel imbalance removed, and absolutely calibrated), POLCAL can and should still be used to check the accuracy of the calibration and to correct it if necessary. Version 4.0 of POLCAL is an upgrade of POLCAL version 2.0 released to AIRSAR investigators in June, 1990. New options in version 4.0 include automatic absolute calibration of 89/90 data, distributed target analysis, calibration of nearby scenes with calibration parameters from a scene with corner reflectors, altitude or roll angle corrections, and calibration of errors introduced by known topography. Many sources of error can lead to false conclusions about the nature of scatterers on the surface. Errors in the phase relationship between polarization channels result in incorrect synthesis of polarization states. Cross-talk, caused by imperfections in the radar antenna itself, can also lead to error. POLCAL reduces cross-talk and corrects phase calibration without the use of ground calibration equipment. Removing the antenna patterns during SAR processing also forms a very important part of the calibration of SAR data. Errors in the

Establishing BRDF calibration capabilities through shortwave infrared

Science.gov (United States)

Georgiev, Georgi T.; Butler, James J.; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2017-09-01

Satellite instruments operating in the reflective solar wavelength region require accurate and precise determination of the Bidirectional Reflectance Distribution Functions (BRDFs) of the laboratory and flight diffusers used in their pre-flight and on-orbit calibrations. This paper advances that initial work and presents a comparison of spectral Bidirectional Reflectance Distribution Function (BRDF) and Directional Hemispherical Reflectance (DHR) of Spectralon*, a common material for laboratory and onorbit flight diffusers. A new measurement setup for BRDF measurements from 900 nm to 2500 nm located at NASA Goddard Space Flight Center (GSFC) is described. The GSFC setup employs an extended indium gallium arsenide detector, bandpass filters, and a supercontinuum light source. Comparisons of the GSFC BRDF measurements in the shortwave infrared (SWIR) with those made by the National Institute of Standards and Technology (NIST) Spectral Tri-function Automated Reference Reflectometer (STARR) are presented. The Spectralon sample used in this study was 2 inch diameter, 99% white pressed and sintered Polytetrafluoroethylene (PTFE) target. The NASA/NIST BRDF comparison measurements were made at an incident angle of 0° and viewing angle of 45° . Additional BRDF data not compared to NIST were measured at additional incident and viewing angle geometries and are not presented here. The total combined uncertainty for the measurement of BRDF in the SWIR range made by the GSFC scatterometer is less than 1% (k = 1). This study is in support of the calibration of the Radiation Budget Instrument (RBI) and Visible Infrared Imaging Radiometer Suit (VIIRS) instruments of the Joint Polar Satellite System (JPSS) and other current and future NASA remote sensing missions operating across the reflected solar wavelength region.

Portable radiation instrumentation traceability of standards and measurements

International Nuclear Information System (INIS)

Wiserman, A.; Walke, M.

1995-01-01

Portable radiation measuring instruments are used to estimate and control doses for workers. Calibration of these instruments must be sufficiently accurate to ensure that administrative and legal dose limits are not likely to be exceeded due to measurement uncertainties. An instrument calibration and management program is established which permits measurements made with an instrument to be traced to a national standard. This paper describes the establishment and maintenance of calibration standards for gamma survey instruments and an instrument management program which achieves traceability of measurement for uniquely identified field instruments. (author)

Calibration factor or calibration coefficient?

International Nuclear Information System (INIS)

Meghzifene, A.; Shortt, K.R.

2002-01-01

Full text: The IAEA/WHO network of SSDLs was set up in order to establish links between SSDL members and the international measurement system. At the end of 2001, there were 73 network members in 63 Member States. The SSDL network members provide calibration services to end-users at the national or regional level. The results of the calibrations are summarized in a document called calibration report or calibration certificate. The IAEA has been using the term calibration certificate and will continue using the same terminology. The most important information in a calibration certificate is a list of calibration factors and their related uncertainties that apply to the calibrated instrument for the well-defined irradiation and ambient conditions. The IAEA has recently decided to change the term calibration factor to calibration coefficient, to be fully in line with ISO [ISO 31-0], which recommends the use of the term coefficient when it links two quantities A and B (equation 1) that have different dimensions. The term factor should only be used for k when it is used to link the terms A and B that have the same dimensions A=k.B. However, in a typical calibration, an ion chamber is calibrated in terms of a physical quantity such as air kerma, dose to water, ambient dose equivalent, etc. If the chamber is calibrated together with its electrometer, then the calibration refers to the physical quantity to be measured per electrometer unit reading. In this case, the terms referred have different dimensions. The adoption by the Agency of the term coefficient to express the results of calibrations is consistent with the 'International vocabulary of basic and general terms in metrology' prepared jointly by the BIPM, IEC, ISO, OIML and other organizations. The BIPM has changed from factor to coefficient. The authors believe that this is more than just a matter of semantics and recommend that the SSDL network members adopt this change in terminology. (author)

Characterization of different qualities in X-rays, for instruments calibration in radiological protection

International Nuclear Information System (INIS)

Cejudo A, J.; Tovar M, V. M.; Vergara M, F.

2010-09-01

In the Secondary Laboratory of Dosimetric Calibration in Mexico was realized the qualities characterization of the series X-rays RQR reported in the International Code of Practices in Dosimetry and Diagnostic Radiology No. 457, using attenuator filters of high purity aluminum and ionizing radiation equipment of inherent filtration of 4 mm Be with and emergent X-radiation beam of 40 grades. For the attenuation was used a geometric arrangement with three beam limiters and a monitor camera prepared on the established form in the mentioned technical report, and a spherical ionization chamber with collection volume of 3.6 cm 3 , aligning its geometric center with the focus of X-rays tube to get that the incident radiation direction will be perpendicular to the ionization chamber. From the perspective of the radiological protection is important to know the X-radiation quality for the application dedicated to the instruments calibration and can to give to these the traceability to a reference laboratory, this way the quality combination and reference chamber can give as a result a procedure for the evaluation of the entrance in surface dose to estimate the dose orientate levels, specified in the basic standards of safety. (Author)

Direct illumination LED calibration for telescope photometry

International Nuclear Information System (INIS)

Barrelet, E.; Juramy, C.

2008-01-01

A calibration method for telescope photometry, based on the direct illumination of a telescope with a calibrated light source regrouping multiple LEDs, is proposed. Its purpose is to calibrate the instrument response. The main emphasis of the proposed method is the traceability of the calibration process and a continuous monitoring of the instrument in order to maintain a 0.2% accuracy over a period of years. Its specificity is to map finely the response of the telescope and its camera as a function of all light ray parameters. This feature is essential to implement a computer model of the instrument representing the variation of the overall light collection efficiency of each pixel for various filter configurations. We report on hardware developments done for SNDICE, the first application of this direct illumination calibration system which will be installed in Canada France Hawaii telescope (CFHT) for its leading supernova experiment (SNLS)

Calibration of EFOSC2 Broadband Linear Imaging Polarimetry

Science.gov (United States)

Wiersema, K.; Higgins, A. B.; Covino, S.; Starling, R. L. C.

2018-03-01

The European Southern Observatory Faint Object Spectrograph and Camera v2 is one of the workhorse instruments on ESO's New Technology Telescope, and is one of the most popular instruments at La Silla observatory. It is mounted at a Nasmyth focus, and therefore exhibits strong, wavelength and pointing-direction-dependent instrumental polarisation. In this document, we describe our efforts to calibrate the broadband imaging polarimetry mode, and provide a calibration for broadband B, V, and R filters to a level that satisfies most use cases (i.e. polarimetric calibration uncertainty 0.1%). We make our calibration codes public. This calibration effort can be used to enhance the yield of future polarimetric programmes with the European Southern Observatory Faint Object Spectrograph and Camera v2, by allowing good calibration with a greatly reduced number of standard star observations. Similarly, our calibration model can be combined with archival calibration observations to post-process data taken in past years, to form the European Southern Observatory Faint Object Spectrograph and Camera v2 legacy archive with substantial scientific potential.

Calibration of the Late Cretaceous to Paleocene geomagnetic polarity and astrochronological time scales: new results from high-precision U-Pb geochronology

Science.gov (United States)

Ramezani, Jahandar; Clyde, William; Wang, Tiantian; Johnson, Kirk; Bowring, Samuel

2016-04-01

Reversals in the Earth's magnetic polarity are geologically abrupt events of global magnitude that makes them ideal timelines for stratigraphic correlation across a variety of depositional environments, especially where diagnostic marine fossils are absent. Accurate and precise calibration of the Geomagnetic Polarity Timescale (GPTS) is thus essential to the reconstruction of Earth history and to resolving the mode and tempo of biotic and environmental change in deep time. The Late Cretaceous - Paleocene GPTS is of particular interest as it encompasses a critical period of Earth history marked by the Cretaceous greenhouse climate, the peak of dinosaur diversity, the end-Cretaceous mass extinction and its paleoecological aftermaths. Absolute calibration of the GPTS has been traditionally based on sea-floor spreading magnetic anomaly profiles combined with local magnetostratigraphic sequences for which a numerical age model could be established by interpolation between an often limited number of 40Ar/39Ar dates from intercalated volcanic ash deposits. Although the Neogene part of the GPTS has been adequately calibrated using cyclostratigraphy-based, astrochronological schemes, the application of these approaches to pre-Neogene parts of the timescale has been complicated given the uncertainties of the orbital models and the chaotic behavior of the solar system this far back in time. Here we present refined chronostratigraphic frameworks based on high-precision U-Pb geochronology of ash beds from the Western Interior Basin of North America and the Songliao Basin of Northeast China that places tight temporal constraints on the Late Cretaceous to Paleocene GPTS, either directly or by testing their astrochronological underpinnings. Further application of high-precision radioisotope geochronology and calibrated astrochronology promises a complete and robust Cretaceous-Paleogene GPTS, entirely independent of sea-floor magnetic anomaly profiles.

Assembly of a laboratory for calibration in brachytherapy. Comparison of responses with different instrumentation

International Nuclear Information System (INIS)

Pirchio, R.; Saravi, M.

2006-01-01

A common practice in quality control programs for dosimetry in brachytherapy is the source calibration. The AAPM (American Association of Physicists in Medicine) in the Task Group No. 40 (TG-40) it recommends that each institution that offers a brachytherapy service verifies the intensity of each source provided by the maker with secondary traceability. For such a reason it is necessary to have laboratories able to make calibrations of sources, traceable electrometer-chambers to primary or credited laboratories. The Regional Center of Reference of Dosimetry of the CNEA (National Commission of Atomic Energy) it is in the stage of finalization of the assembly of a Laboratory for source calibration and use equipment in brachytherapy. For it has two ionization chambers well type and two electrometers gauged by the Accredited Dosimetry Calibration Laboratory of the University of Wisconsin. Also account with a wide variety of supports and with a tube of 137 Cs pattern 3M model 6500/6D6C. The procedures for the calibration of sources and equipment were elaborated starting from the TECDOC-1274. On the other hand, its were carried out measurements with different instrumentation for the comparison of responses and at the same time to implement the calibration procedures. For it, its were used chambers and electrometers of the institution, of hospitals and of the national company 'Solydes'. In the measurements its were used seeds of 125 I taken place in Argentina and the tube of 137 Cs pattern mentioned previously. In first place it was proceeded to the determination of the center of the region of the plateau in the axial response for the seeds of Iodine-125 and the tube of Cesium-137 pattern using different chambers. Later on its were carried out measurements of accumulated loads during a certain interval of time in this position. The calibration factors of each chamber were determined, N Sk (μGy m 2 h -1 A -1 ), as the quotient of the kerma rate in reference air of the

Decision-Making by Handball Referees: Design of an ad hoc Observation Instrument and Polar Coordinate Analysis.

Science.gov (United States)

Morillo, Juan P; Reigal, Rafael E; Hernández-Mendo, Antonio; Montaña, Alejandro; Morales-Sánchez, Verónica

2017-01-01

Referees are essential for sports such as handball. However, there are few tools available to analyze the activity of handball referees. The aim of this study was to design an instrument for observing the behavior of referees in handball competitions and to analyze the resulting data by polar coordinate analysis. The instrument contained 6 criteria and 18 categories and can be used to monitor and describe the actions of handball referees according to their role/position on the playing court. For the data quality control analysis, we calculated Pearson's (0.99), Spearman's (0.99), and Tau Kendall's (1.00) correlation coefficients and Cohen's kappa (entre 0.72 y 0.75) and Phi (entre 0.83 y 0.87) coefficients. In the generalizability analysis, the absolute and relative generalizability coefficients were 0.99 in both cases. Polar coordinate analysis of referee decisions showed that correct calls were more common for central court and 7-meter throw calls. Likewise, calls were more likely to be incorrect (in terms of both errors of omission and commission) when taken from the goal-line position.

Decision-Making by Handball Referees: Design of an ad hoc Observation Instrument and Polar Coordinate Analysis

Directory of Open Access Journals (Sweden)

Juan P. Morillo

2017-10-01

Full Text Available Referees are essential for sports such as handball. However, there are few tools available to analyze the activity of handball referees. The aim of this study was to design an instrument for observing the behavior of referees in handball competitions and to analyze the resulting data by polar coordinate analysis. The instrument contained 6 criteria and 18 categories and can be used to monitor and describe the actions of handball referees according to their role/position on the playing court. For the data quality control analysis, we calculated Pearson's (0.99, Spearman's (0.99, and Tau Kendall's (1.00 correlation coefficients and Cohen's kappa (entre 0.72 y 0.75 and Phi (entre 0.83 y 0.87 coefficients. In the generalizability analysis, the absolute and relative generalizability coefficients were 0.99 in both cases. Polar coordinate analysis of referee decisions showed that correct calls were more common for central court and 7-meter throw calls. Likewise, calls were more likely to be incorrect (in terms of both errors of omission and commission when taken from the goal-line position.

Calibration of the MSL/ChemCam/LIBS Remote Sensing Composition Instrument

Science.gov (United States)

Wiens, R. C.; Maurice S.; Bender, S.; Barraclough, B. L.; Cousin, A.; Forni, O.; Ollila, A.; Newsom, H.; Vaniman, D.; Clegg, S.;

SCIAMACHY Level 1 data: calibration concept and in-flight calibration

Science.gov (United States)

Lichtenberg, G.; Kleipool, Q.; Krijger, J. M.; van Soest, G.; van Hees, R.; Tilstra, L. G.; Acarreta, J. R.; Aben, I.; Ahlers, B.; Bovensmann, H.; Chance, K.; Gloudemans, A. M. S.; Hoogeveen, R. W. M.; Jongma, R. T. N.; Noël, S.; Piters, A.; Schrijver, H.; Schrijvers, C.; Sioris, C. E.; Skupin, J.; Slijkhuis, S.; Stammes, P.; Wuttke, M.

2006-11-01

The calibration of SCIAMACHY was thoroughly checked since the instrument was launched on-board ENVISAT in February 2002. While SCIAMACHY's functional performance is excellent since launch, a number of technical difficulties have appeared, that required adjustments to the calibration. The problems can be separated into three types: (1) Those caused by the instrument and/or platform environment. Among these are the high water content in the satellite structure and/or MLI layer. This results in the deposition of ice on the detectors in channels 7 and 8 which seriously affects the retrievals in the IR, mostly because of the continuous change of the slit function caused by scattering of the light through the ice layer. Additionally a light leak in channel 7 severely hampers any retrieval from this channel. (2) Problems due to errors in the on-ground calibration and/or data processing affecting for example the radiometric calibration. A new approach based on a mixture of on-ground and in-flight data is shortly described here. (3) Problems caused by principal limitations of the calibration concept, e.g. the possible appearance of spectral structures after the polarisation correction due to unavoidable errors in the determination of atmospheric polarisation. In this paper we give a complete overview of the calibration and problems that still have to be solved. We will also give an indication of the effect of calibration problems on retrievals where possible. Since the operational processing chain is currently being updated and no newly processed data are available at this point in time, for some calibration issues only a rough estimate of the effect on Level 2 products can be given. However, it is the intention of this paper to serve as a future reference for detailed studies into specific calibration issues.

The Moon Mineralogy Mapper (M3) imaging spectrometerfor lunar science: Instrument description, calibration, on‐orbit measurements, science data calibration and on‐orbit validation

Science.gov (United States)

C. Pieters,; P. Mouroulis,; M. Eastwood,; J. Boardman,; Green, R.O.; Glavich, T.; Isaacson, P.; Annadurai, M.; Besse, S.; Cate, D.; Chatterjee, A.; Clark, R.; Barr, D.; Cheek, L.; Combe, J.; Dhingra, D.; Essandoh, V.; Geier, S.; Goswami, J.N.; Green, R.; Haemmerle, V.; Head, J.; Hovland, L.; Hyman, S.; Klima, R.; Koch, T.; Kramer, G.; Kumar, A.S.K.; Lee, K.; Lundeen, S.; Malaret, E.; McCord, T.; McLaughlin, S.; Mustard, J.; Nettles, J.; Petro, N.; Plourde, K.; Racho, C.; Rodriguez, J.; Runyon, C.; Sellar, G.; Smith, C.; Sobel, H.; Staid, M.; Sunshine, J.; Taylor, L.; Thaisen, K.; Tompkins, S.; Tseng, H.; Vane, G.; Varanasi, P.; White, M.; Wilson, D.

2011-01-01

The NASA Discovery Moon Mineralogy Mapper imaging spectrometer was selected to pursue a wide range of science objectives requiring measurement of composition at fine spatial scales over the full lunar surface. To pursue these objectives, a broad spectral range imaging spectrometer with high uniformity and high signal-to-noise ratio capable of measuring compositionally diagnostic spectral absorption features from a wide variety of known and possible lunar materials was required. For this purpose the Moon Mineralogy Mapper imaging spectrometer was designed and developed that measures the spectral range from 430 to 3000 nm with 10 nm spectral sampling through a 24 degree field of view with 0.7 milliradian spatial sampling. The instrument has a signal-to-noise ratio of greater than 400 for the specified equatorial reference radiance and greater than 100 for the polar reference radiance. The spectral cross-track uniformity is >90% and spectral instantaneous field-of-view uniformity is >90%. The Moon Mineralogy Mapper was launched on Chandrayaan-1 on the 22nd of October. On the 18th of November 2008 the Moon Mineralogy Mapper was turned on and collected a first light data set within 24 h. During this early checkout period and throughout the mission the spacecraft thermal environment and orbital parameters varied more than expected and placed operational and data quality constraints on the measurements. On the 29th of August 2009, spacecraft communication was lost. Over the course of the flight mission 1542 downlinked data sets were acquired that provide coverage of more than 95% of the lunar surface. An end-to-end science data calibration system was developed and all measurements have been passed through this system and delivered to the Planetary Data System (PDS.NASA.GOV). An extensive effort has been undertaken by the science team to validate the Moon Mineralogy Mapper science measurements in the context of the mission objectives. A focused spectral, radiometric

Calibration of the Large Area X-Ray Proportional Counter (LAXPC) Instrument on board AstroSat

Energy Technology Data Exchange (ETDEWEB)

Antia, H. M.; Yadav, J. S.; Chauhan, Jai Verdhan; Chitnis, Varsha; Dedhia, Dhiraj; Shah, Parag; Gujar, V. M.; Katoch, Tilak; Kurhade, V. N.; Madhwani, Pankaj; Manojkumar, T. K.; Nikam, V. A.; Pandya, A. S.; Parmar, J. V.; Pawar, D. M. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Agrawal, P. C. [UM-DAE Centre of Excellence for Basic Sciences, University of Mumbai, Kalina, Mumbai 400098 (India); Manchanda, R. K. [University of Mumbai, Kalina, Mumbai 400098 (India); Paul, Biswajit [Department of Astronomy and Astrophysics, Raman Research Institute, Bengaluru 560080 (India); Pahari, Mayukh; Misra, Ranjeev [Inter-University Centre for Astronomy and Astrophysics, Pune 411007 (India); and others

2017-07-01

We present the calibration and background model for the Large Area X-ray Proportional Counter (LAXPC) detectors on board AstroSat . The LAXPC instrument has three nominally identical detectors to achieve a large collecting area. These detectors are independent of each other, and in the event analysis mode they record the arrival time and energy of each photon that is detected. The detectors have a time resolution of 10 μ s and a dead-time of about 42 μ s. This makes LAXPC ideal for timing studies. The energy resolution and peak channel-to-energy mapping were obtained from calibration on the ground using radioactive sources coupled with GEANT4 simulations of the detectors. The response matrix was further refined from observations of the Crab after launch. At around 20 keV the energy resolution of the detectors is 10%–15%, while the combined effective area of the three detectors is about 6000 cm{sup 2}.

Design, calibration and error analysis of instrumentation for heat transfer measurements in internal combustion engines

Science.gov (United States)

Ferguson, C. R.; Tree, D. R.; Dewitt, D. P.; Wahiduzzaman, S. A. H.

1987-01-01

The paper reports the methodology and uncertainty analyses of instrumentation for heat transfer measurements in internal combustion engines. Results are presented for determining the local wall heat flux in an internal combustion engine (using a surface thermocouple-type heat flux gage) and the apparent flame-temperature and soot volume fraction path length product in a diesel engine (using two-color pyrometry). It is shown that a surface thermocouple heat transfer gage suitably constructed and calibrated will have an accuracy of 5 to 10 percent. It is also shown that, when applying two-color pyrometry to measure the apparent flame temperature and soot volume fraction-path length, it is important to choose at least one of the two wavelengths to lie in the range of 1.3 to 2.3 micrometers. Carefully calibrated two-color pyrometer can ensure that random errors in the apparent flame temperature and in the soot volume fraction path length will remain small (within about 1 percent and 10-percent, respectively).

Performance standard for dose Calibrator

CERN Document Server

Darmawati, S

2002-01-01

Dose calibrator is an instrument used in hospitals to determine the activity of radionuclide for nuclear medicine purposes. International Electrotechnical Commission (IEC) has published IEC 1303:1994 standard that can be used as guidance to test the performance of the instrument. This paper briefly describes content of the document,as well as explains the assessment that had been carried out to test the instrument accuracy in Indonesia through intercomparison measurement.Its is suggested that hospitals acquire a medical physicist to perform the test for its dose calibrator. The need for performance standard in the form of Indonesia Standard is also touched.

Exposure-rate calibration using large-area calibration pads

International Nuclear Information System (INIS)

Novak, E.F.

1988-09-01

The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center (TMC) at the DOE Grand Junction Projects Office (GJPO) in Grand Junction, Colorado, to standardize, calibrate, and compare measurements made in support of DOE remedial action programs. A set of large-area, radioelement-enriched concrete pads was constructed by the DOE in 1978 at the Walker Field Airport in Grand Junction for use as calibration standards for airborne gamma-ray spectrometer systems. The use of these pads was investigated by the TMC as potential calibration standards for portable scintillometers employed in measuring gamma-ray exposure rates at Uranium Mill Tailings Remedial Action (UMTRA) project sites. Data acquired on the pads using a pressurized ionization chamber (PIC) and three scintillometers are presented as an illustration of an instrumental calibration. Conclusions and recommended calibration procedures are discussed, based on the results of these data

CryoSat/SIRAL Cal1 Calibration Orbits

Science.gov (United States)

Scagliola, Michele; Fornari, Marco; Bouffard, Jerome; Parrinello, Tommaso

2017-04-01

The main payload of CryoSat is a Ku band pulsewidth limited radar altimeter, called SIRAL (Synthetic interferometric radar altimeter), that transmits pulses at a high pulse repetition frequency thus making the received echoes phase coherent and suitable for SAR processing. This allows to reach an along track resolution that is significantly improved with respect to traditional pulse-width limited altimeters. Due to the fact that SIRAL is a phase coherent pulse-width limited radar altimeter, a proper calibration approach has been developed. In fact, not only corrections for transfer function, gain and instrument path delay have to be computed (as in previous altimeters), but also corrections for phase (SAR/SARIn) and phase difference between the two receiving chains (SARIN only). Recalling that the CryoSat's orbit has a high inclination of 92° and it is non-sun-synchronous, the temperature of the SIRAL changes continuously along the orbit with a period of about 480 days and it is also function of the ascending/descending passes. By analysis of the CAL1 calibration corrections, it has been verified that the internal path delay and the instrument gain variation measured on the SIRAL are affected by the thermal status of the instrument and as a consequence they are expected to vary along the orbit. In order to gain knowledge on the calibration corrections (i.e. the instrument behavior) as function of latitude and temperature, it has been planned to command a few number of orbits where only CAL1 calibration acquisitions are continuously performed. The analysis of the CAL1 calibration corrections produced along the Calibration orbits can be also useful to verify whether the current calibration plan is able to provide sufficiently accurate corrections for the instrument acquisitions at any latitude. In 2016, the CryoSat/SIRAL Cal1 Calibration Orbits have been commanded two times, a first time the 20th of July 2016 and a second time the 24th of November 2016, and they

Establishment of 137Cs radiation fields for instrument calibration

International Nuclear Information System (INIS)

Albuquerque, M. da P.P.; Caldas, L.V.E.; Xavier, M.

1988-09-01

In order to study the energy dependence of clinical dosemeters, systems constituted of ionization chambers connected to special electrometers, many times their calibration with the gamma radiation of 137 Cs is necessary. In this case, the radiation field characterization is fundamental. The source used presents and activity of 38,8 Tbq and belongs to the Calibration Laboratory of IPEN. Dosimetric films, gammagraphy films, ionization chambers and Lucite phantons were used. At the calibration distance, 80 cm (detector-source detection), the homogeneity of a 10 X 10 cm 2 radiation field was equal 68%. (author) [pt

Design of a nondestructive two-in-one instrument for measuring the polarization and energy spectrum at an X-ray FEL facility

Science.gov (United States)

Zhang, Qingmin; Deng, Bangjie; Chen, Yuanmiaoliang; Liu, Bochao; Chen, Shaofei; Fan, Jinquan; Feng, Lie; Deng, Haixiao; Liu, Bo; Wang, Dong

2017-10-01

The free electron laser (FEL), as a next-generation light source, is an attractive tool in scientific frontier research because of its advantages of full coherence, ultra-short pulse duration, and controllable polarization. Owing to the demand of real-time bunch diagnosis during FEL experiments, precise nondestructive measurements of the polarization and X-ray energy spectrum using one instrument are preferred. In this paper, such an instrument based on the electron time-of-flight technique is proposed. By considering the complexity and nonlinearity, a numerical model in the framework of Geant4 has been developed for optimization. Taking the Shanghai Soft X-ray FEL user facility as an example, its measurement performances' dependence on the critical parameters was studied systematically, and, finally, an optimal design was obtained, achieving resolutions of 0.5% for the polarization degree and 0.3 eV for the X-ray energy spectrum.

Quality assurance programs at the PNL calibrations laboratory

International Nuclear Information System (INIS)

Piper, R.K.; McDonald, J.C.; Fox, R.A.; Eichner, F.N.

1993-03-01

The calibrations laboratory at Pacific Northwest Laboratory (PNL) serves as a radiological standardization facility for personnel and environmental dosimetry and radiological survey instruments. As part of this function, the calibrations laboratory must maintain radiological reference fields with calibrations traceable to the National Institute of Standards and Technology (NIST). This task is accomplished by a combination of (1) sources or reference instruments calibrated at or by NIST, (2) measurement quality assurance (MQA) interactions with NIST, and (3) rigorous internal annual and quarterly calibration verifications. This paper describes a representative sample of the facilities, sources, and actions used to maintain accurate and traceable fields

CryoSat SIRAL Calibration and Performance

Science.gov (United States)

Fornari, Marco; Scagliola, Michele; Tagliani, Nicolas; Parrinello, Tommaso

2013-04-01

The main payload of CryoSat is a Ku band pulse-width limited radar altimeter, called SIRAL (Synthetic interferometric radar altimeter), that transmits pulses at a high pulse repetition frequency thus making the received echoes phase coherent and suitable for azimuth processing. This allows to reach an along track resolution of about 250 meters which is a significant improvement over traditional pulse-width limited altimeters. Due to the fact that SIRAL is a phase coherent pulse-width limited radar altimeter, a proper calibration approach has been developed, including both an internal and external calibration. The internal calibration monitors the instrument impulse response and the transfer function, like traditional altimeters. In addition to that, the interferometer requires a special calibration developed ad hoc for SIRAL. The external calibration is performed with the use of a ground transponder, located in Svalbard, which receives SIRAL signal and sends the echo back to the satellite. Internal calibration data are processed on ground by the CryoSat Instrument Processing Facility (IPF1) and then applied to the science data. By April 2013, almost 3 years of calibration data will be available, which will be shown in this poster. The external calibration (transponder) data are processed and analyzed independently from the operational chain. The use of an external transponder has been very useful to determine instrument performance and for the tuning of the on-ground processor. This poster presents the transponder results in terms of range noise and datation error.

Principal components based support vector regression model for on-line instrument calibration monitoring in NPPs

International Nuclear Information System (INIS)

Seo, In Yong; Ha, Bok Nam; Lee, Sung Woo; Shin, Chang Hoon; Kim, Seong Jun

2010-01-01

In nuclear power plants (NPPs), periodic sensor calibrations are required to assure that sensors are operating correctly. By checking the sensor's operating status at every fuel outage, faulty sensors may remain undetected for periods of up to 24 months. Moreover, typically, only a few faulty sensors are found to be calibrated. For the safe operation of NPP and the reduction of unnecessary calibration, on-line instrument calibration monitoring is needed. In this study, principal component based auto-associative support vector regression (PCSVR) using response surface methodology (RSM) is proposed for the sensor signal validation of NPPs. This paper describes the design of a PCSVR-based sensor validation system for a power generation system. RSM is employed to determine the optimal values of SVR hyperparameters and is compared to the genetic algorithm (GA). The proposed PCSVR model is confirmed with the actual plant data of Kori Nuclear Power Plant Unit 3 and is compared with the Auto-Associative support vector regression (AASVR) and the auto-associative neural network (AANN) model. The auto-sensitivity of AASVR is improved by around six times by using a PCA, resulting in good detection of sensor drift. Compared to AANN, accuracy and cross-sensitivity are better while the auto-sensitivity is almost the same. Meanwhile, the proposed RSM for the optimization of the PCSVR algorithm performs even better in terms of accuracy, auto-sensitivity, and averaged maximum error, except in averaged RMS error, and this method is much more time efficient compared to the conventional GA method

Calibration of optical cantilever deflection readers

International Nuclear Information System (INIS)

Hu Zhiyu; Seeley, Tim; Kossek, Sebastian; Thundat, Thomas

2004-01-01

Because of its ultrahigh sensitivity, the optical lever detection method similar to that used in the atomic force microscope (AFM) has been widely employed as a standard technique for measuring microcantilever deflection. Along with the increasing interest in using the microcantilever as a sensing platform, there is also a requirement for a reliable calibration technique. Many researchers have used the concept of optical lever detection to construct microcantilever deflection readout instruments for chemical, physical, and biological detection. However, without an AFM piezo z scanner, it is very difficult to precisely calibrate these instruments. Here, we present a step-by-step method to conveniently calibrate an instrument using commercially available piezoresistive cantilevers. The experimental results closely match the theoretical calculation. Following this procedure, one can easily calibrate any optical cantilever deflection detection system with high reproducibility, precision, and reliability. A detailed discussion of the optical lever readout system design has been addressed in this article

Instrumentation to handle thermal polarized neutron beams

NARCIS (Netherlands)

Kraan, W.H.

2004-01-01

In this thesis we investigate devices needed to handle the polarization of thermal neutron beams: Ï/2-flippers (to start/stop Larmor precession) and Ï-flippers (to reverse polarization/precession direction) and illustrate how these devices are used to investigate the properties of matter and of the

Instruments for calibration and monitoring of the LHCb Muon Detector

CERN Document Server

Deplano, C; Lai, A

2006-01-01

The subject of this Ph. D. thesis is the study and the development of the instruments needed to monitor and calibrate the Muon Detector of the LHCb (Large Hadron Collider beauty) experiment. LHCb is currently under installation at the CERN Large Hadron Collider (LHC) and will start to take data during 2007. The experiment will study B mesons decays to achieve a profound understanding of favour physics in the Standard Model framework and to search signs of new physics beyond. Muons can be found in the final states of many B-decays which are sensitive to CP violation. The Muon Detector has the crucial role to identify the muon particles generated by the b-hadron decays through a measurement of their transverse momentum, already at the first trigger level (Level-0). A 95% effciency in events selection is required for the Muon Trigger, which operates at the Level-0. 1380 detectors are used to equip the whole Muon System and the corresponding 122,112 readout channels must be time aligned and monitored with a resol...

Inter-satellite calibration of FengYun 3 medium energy electron fluxes with POES electron measurements

Science.gov (United States)

Zhang, Yang; Ni, Binbin; Xiang, Zheng; Zhang, Xianguo; Zhang, Xiaoxin; Gu, Xudong; Fu, Song; Cao, Xing; Zou, Zhengyang

2018-05-01

We perform an L-shell dependent inter-satellite calibration of FengYun 3 medium energy electron measurements with POES measurements based on rough orbital conjunctions within 5 min × 0.1 L × 0.5 MLT. By comparing electron flux data between the U.S. Polar Orbiting Environmental Satellites (POES) and Chinese sun-synchronous satellites including FY-3B and FY-3C for a whole year of 2014, we attempt to remove less reliable data and evaluate systematic uncertainties associated with the FY-3B and FY-3C datasets, expecting to quantify the inter-satellite calibration factors for the 150-350 keV energy channel at L = 2-7. Compared to the POES data, the FY-3B and FY-3C data generally exhibit a similar trend of electron flux variations but more or less underestimate them within a factor of 5 for the medium electron energy 150-350 keV channel. Good consistency in the flux conjunctions after the inter-calibration procedures gives us certain confidence to generalize our method to calibrate electron flux measurements from various satellite instruments.

Development of nano-roughness calibration standards

International Nuclear Information System (INIS)

Baršić, Gorana; Mahović, Sanjin; Zorc, Hrvoje

2012-01-01

At the Laboratory for Precise Measurements of Length, currently the Croatian National Laboratory for Length, unique nano-roughness calibration standards were developed, which have been physically implemented in cooperation with the company MikroMasch Trading OU and the Ruđer Bošković Institute. In this paper, a new design for a calibration standard with two measuring surfaces is presented. One of the surfaces is for the reproduction of roughness parameters, while the other is for the traceability of length units below 50 nm. The nominal values of the groove depths on these measuring surfaces are the same. Thus, a link between the measuring surfaces has been ensured, which makes these standards unique. Furthermore, the calibration standards available on the market are generally designed specifically for individual groups of measuring instrumentation, such as interferometric microscopes, stylus instruments, scanning electron microscopes (SEM) or scanning probe microscopes. In this paper, a new design for nano-roughness standards has been proposed for use in the calibration of optical instruments, as well as for stylus instruments, SEM, atomic force microscopes and scanning tunneling microscopes. Therefore, the development of these new nano-roughness calibration standards greatly contributes to the reproducibility of the results of groove depth measurement as well as the 2D and 3D roughness parameters obtained by various measuring methods. (paper)

Application of methodology for calibration of instruments utilized in dosimetry of high energy beams, for radiodiagnosis

International Nuclear Information System (INIS)

Potiens, Maria P.A.; Caldas, Linda V.E.

2000-01-01

The radiation qualities recommended by the IEC 1267 standard for the calibration of instruments used in diagnostic radiology measurements were established using a neo-diagnomax X-ray system (125 kV). The RQR radiation qualities are recommended to test ionization chambers used in non attenuated beams, and the RQA radiation qualities in attenuated beams (behind a phantom). To apply the methodology, 6 ionization chambers commonly used in diagnostic radiology were tested. The higher energy dependence (17%) was obtained for an ionization chamber recommended for mammography beams, that is not the case of the X radiation system used in this work. The other ionization chambers presented good performance in terms of energy (maximum of 5%), therefore within the limits of the international recommendations for this kind of instrument. (author)

Polarization modeling and predictions for DKIST part 3: focal ratio and thermal dependencies of spectral polarization fringes and optic retardance

Science.gov (United States)

Harrington, David M.; Sueoka, Stacey R.

2018-01-01

Data products from high spectral resolution astronomical polarimeters are often limited by fringes. Fringes can skew derived magnetic field properties from spectropolarimetric data. Fringe removal algorithms can also corrupt the data if the fringes and object signals are too similar. For some narrow-band imaging polarimeters, fringes change the calibration retarder properties and dominate the calibration errors. Systems-level engineering tools for polarimetric instrumentation require accurate predictions of fringe amplitudes, periods for transmission, diattenuation, and retardance. The relevant instabilities caused by environmental, thermal, and optical properties can be modeled and mitigation tools developed. We create spectral polarization fringe amplitude and temporal instability predictions by applying the Berreman calculus and simple interferometric calculations to optics in beams of varying F/ number. We then apply the formalism to superachromatic six-crystal retarders in converging beams under beam thermal loading in outdoor environmental conditions for two of the world's largest observatories: the 10-m Keck telescope and the Daniel K. Inouye Solar Telescope (DKIST). DKIST will produce a 300-W optical beam, which has imposed stringent requirements on the large diameter six-crystal retarders, dichroic beamsplitters, and internal optics. DKIST retarders are used in a converging beam with F/ ratios between 8 and 62. The fringe spectral periods, amplitudes, and thermal models of retarder behavior assisted DKIST optical designs and calibration plans with future application to many astronomical spectropolarimeters. The Low Resolution Imaging Spectrograph with polarimetry instrument at Keck also uses six-crystal retarders in a converging F / 13 beam in a Cassegrain focus exposed to summit environmental conditions providing observational verification of our predictions.

pH sensor calibration procedure

OpenAIRE

Artero Delgado, Carola; Nogueras Cervera, Marc; Manuel Lázaro, Antonio; Prat Tasias, Jordi; Prat Farran, Joana d'Arc

2013-01-01

This paper describes the calibration of pH sensor located at the OBSEA marine Observatory. This instrument is based on an industrial pH electrode that is connected to a CTD instrument (Conductivity, Temperature, and Depth ). The calibration of the pH sensor has been done using a high precision spectrophotometer pH meter from Institute of Marine Sciences (ICM), and in this way it has been obtained a numerical function for the p H sensor propor...

Calibration pipeline for VIR data

Science.gov (United States)

Carraro, F.; Fonte, S.; Coradini, A.; Filacchione, G.; de Sanctis, M. C.; Ammannito, E.; Capria, M. T.; Cartacci, M.; Noschese, R.; Tosi, F.; Capaccioni, F.

2011-10-01

During the second quarter of 2011 VIR-MS (VIS and IR Mapping Spectrometer) [1] aboard Dawn mission [2] has approached Vesta in order to start a long period of acquisitions that will end at the beginning of 2012. Data acquired by each instrument always require a calibration process in order to remove all the instrument effects that could affect the scientific evaluations and analysis. VIR-MS instrument team has realized a calibration pipeline which has the goal of producing calibrated (1b level) data starting from the raw (1a level) ones. The other goal of the tool has been the check of the goodness of acquired data by means of the evaluation of a series of minimum requisites of each data file, such as the percentage of the saturated pixels, the presence of spikes or the mean S/N ratio of each qube.

Calibration of a radiation survey meter using Cs-137 gamma source

International Nuclear Information System (INIS)

Khalid, R. O.

2005-07-01

The survey instrument smartIon was calibrated at the Secondary Standard Dosimetry Laboratory, Sudan Atomic Energy Commission, in terms of kerma, free in air using Cs-137 gamma radiation. All the calibrations were performed using the reference instrument spherical ionization chamber LS-01. This reference instrument has been calibrated at the International Atomic Energy Agency, Vienna for x-rays, 137 Cs and 60 Co gamma radiation. The air kerma calibration factors for the instrument were determined as the ratio of the dose rates obtained with the reference standard chamber LS-01 and the dose rates of the instrument under calibration. The uncertainties for the survey meter smartIon and another survey meter RADOS were obtained and the results compared with the uncertainty for the reference standard chamber. Also, the values of dose rates were obtained for various angles of the incident beam, by changing the angle by which the radiation was incident on the sensitive point of the instrument.(Author)

Mars 2020 Rover SHERLOC Calibration Target

Science.gov (United States)

Graff, Trevor; Fries, Marc; Burton, Aaron; Ross, Amy; Larson, Kristine; Garrison, Dan; Calaway, Mike; Tran, Vinh; Bhartia, Roh; Beegle, Luther

2016-01-01

The Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument is a deep ultraviolet (UV) Raman Fluorescence instrument selected as part of the Mars 2020 rover instrument suite. SHERLOC will be mounted on the rover arm and its primary role is to identify carbonaceous species in martian samples. The SHERLOC instrument requires a calibration target which is being designed and fabricated at JSC as part of our continued science participation in Mars robotic missions. The SHERLOC calibration target will address a wide range of NASA goals to include basic science of interest to both the Science Mission Directorate and Human Exploration and Operations Mission Directorate.

Shield calculation of project for instrument calibration integrated laboratory of IPEN-Sao Paulo, Brazil

International Nuclear Information System (INIS)

Barros, Gustavo A.S.J.; Caldas, Linda V.E.

2009-01-01

This work performed the shield calculation of the future rooms walls of the five X-ray equipment of the Instrument Calibration Laboratory of the IPEN, Sao Paulo, Brazil, which will be constructed in project of laboratory enlargement. The obtained results by application of a calculation methodology from an international regulation have shown that the largest thickness of shielding (25.7 cm of concrete or 7.1 mm of lead) will be of the wall which will receive the primary beam of the equipment with a 320 kV voltage. The cost/benefit analysis indicated the concrete as the best material option for the shielding

Calibration method of radiation monitoring system at TQNPC

International Nuclear Information System (INIS)

Liu Zhengshan; Zhang Qingli; Liu Jinjin; Miao Yuxing; Geng Lixin; Zhuang Yun; Dong Jianfeng; He Change

2009-04-01

The calibration methods and calibration device for standard monitor of radioactive particulate, iodine, noble gas and so on are not yet set up at home. On consideration of the present situation of the radiation monitoring system at the Third Qinshan Nuclear Power Co. Ltd., we have studied the calibration method of these radiation monitoring instruments used for measuring the waste liquid, particulate, iodine and noble gas produced during the operation of nuclear reactor. Through the check against these instruments during the No. 202 and No. 103 overhaul, we got initially the method of the calibration and obtained the transfer coefficient of calibration when secondary solid sources are used for calibration. Through the testing and calibration, the credibility of the radiation monitoring system is enhanced. And at the same time, the problems existing in the calibration are discussed. (authors)

The Use of Color Sensors for Spectrographic Calibration

Science.gov (United States)

Thomas, Neil B.

2018-04-01

The wavelength calibration of spectrographs is an essential but challenging task in many disciplines. Calibration is traditionally accomplished by imaging the spectrum of a light source containing features that are known to appear at certain wavelengths and mapping them to their location on the sensor. This is typically required in conjunction with each scientific observation to account for mechanical and optical variations of the instrument over time, which may span years for certain projects. The method presented here investigates the usage of color itself instead of spectral features to calibrate a spectrograph. The primary advantage of such a calibration is that any broad-spectrum light source such as the sky or an incandescent bulb is suitable. This method allows for calibration using the full optical pathway of the instrument instead of incorporating separate calibration equipment that may introduce errors. This paper focuses on the potential for color calibration in the field of radial velocity astronomy, in which instruments must be finely calibrated for long periods of time to detect tiny Doppler wavelength shifts. This method is not restricted to radial velocity, however, and may find application in any field requiring calibrated spectrometers such as sea water analysis, cellular biology, chemistry, atmospheric studies, and so on. This paper demonstrates that color sensors have the potential to provide calibration with greatly reduced complexity.

CryoSat-2 SIRAL Calibration: Strategy, Application and Results

Science.gov (United States)

Parrinello, T.; Fornari, M.; Bouzinac, C.; Scagliola, M.; Tagliani, N.

2012-04-01

The main payload of CryoSat-2 is a Ku band pulsewidth limited radar altimeter, called SIRAL (Synthetic interferometric radar altimeter), that transmits pulses at a high pulse repetition frequency thus making the received echoes phase coherent and suitable for azimuth processing. This allows to reach an along track resolution of about 250 meters which is an important improvement over traditional pulse-width limited altimeters. Due to the fact that SIRAL is a phase coherent pulse-width limited radar altimeter, a proper calibration approach has been developed. In fact, not only the corrections for transfer function amplitude with respect to frequency, gain and instrument path delay have to be computed but it is also needed to provide corrections for transfer function phase with respect to frequency and AGC setting as well as the phase variation across bursts of pulses. As a consequence, SIRAL performs regularly four types of calibrations: (1) CAL1 in order to calibrate the internal path delay and peak power variation, (2) CAL2 in order to compensate the instrument transfer function, (3) CAL4 to calibrate the interferometer and (4) AutoCal, a specific sequence in order to calibrate the gain and phase difference for each AGC setting. Commissioning phase results (April-December 2010) revealed high stability of the instrument, which made possible to reduce the calibration frequency during Operations. Internal calibration data are processed on ground by the CryoSat-2 Instrument Processing Facility (IPF1) and then applied to the science data. In this poster we will describe as first the calibration strategy and then how the four different types of calibration are applied to science data. Moreover the calibration results over almost 2 years of mission will be presented, analyzing their temporal evolution in order to highlight the stability of the instrument over its life.

Calibration of ground-based Lidar instrument WLS7-73

DEFF Research Database (Denmark)

Yordanova, Ginka; Gómez Arranz, Paula

This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain...

Mathematical calibration of Ge detectors, and the instruments that use them

International Nuclear Information System (INIS)

Bronson, F.L.; Young, B.

1997-01-01

Efficiency calibrations for Ge detectors are typically done with the use of multiple energy calibrations sources which are added to a bulk matrix intended to simulate the measurement sample, and then deposited in the sample container. This is rather easy for common laboratory samples. Bu, even there, for many environmental samples, waste assay samples, and operational health physics samples, accurate calibrations are difficult. For these situations, various mathematical corrections or direct calibration techniques are used at Canberra. EML has pioneered the use of mathematical calibrations following source-based detector characterization measurements for in situ measurements of environmental fallout. Canberra has expanded this by the use of MCNP for the source measurements required in EML. For other calibration situations, MCNP was used directly, as the primary calibration method. This is demonstrated to be at least as accurate as source based measurements, and probably better. Recently, a new method [ISOCS] has been developed and is nearing completion. This promises to be an easy to use calibration software that can be used by the customer for in situ gamma spectroscopy to accurately measure many large sized samples, such as boxes, drums, pipes, or to calibrate small laboratory-type samples. 8 refs., 8 figs., 5 tabs

Mathematical calibration of Ge detectors, and the instruments that use them

Energy Technology Data Exchange (ETDEWEB)

Bronson, F.L.; Young, B. [Canberra Industries, Meriden, CT (United States)

1997-11-01

Efficiency calibrations for Ge detectors are typically done with the use of multiple energy calibrations sources which are added to a bulk matrix intended to simulate the measurement sample, and then deposited in the sample container. This is rather easy for common laboratory samples. Bu, even there, for many environmental samples, waste assay samples, and operational health physics samples, accurate calibrations are difficult. For these situations, various mathematical corrections or direct calibration techniques are used at Canberra. EML has pioneered the use of mathematical calibrations following source-based detector characterization measurements for in situ measurements of environmental fallout. Canberra has expanded this by the use of MCNP for the source measurements required in EML. For other calibration situations, MCNP was used directly, as the primary calibration method. This is demonstrated to be at least as accurate as source based measurements, and probably better. Recently, a new method [ISOCS] has been developed and is nearing completion. This promises to be an easy to use calibration software that can be used by the customer for in situ gamma spectroscopy to accurately measure many large sized samples, such as boxes, drums, pipes, or to calibrate small laboratory-type samples. 8 refs., 8 figs., 5 tabs.

Bicep2. III. INSTRUMENTAL SYSTEMATICS

Energy Technology Data Exchange (ETDEWEB)

Ade, P. A. R. [School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA (United Kingdom); Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Filippini, J. P.; Golwala, S. R.; Hildebrandt, S. R. [Department of Physics, California Institute of Technology, Pasadena, CA 91125 (United States); Barkats, D. [Joint ALMA Observatory, ESO, Santiago (Chile); Benton, S. J. [Department of Physics, University of Toronto, Toronto, ON (Canada); Bischoff, C. A.; Buder, I.; Karkare, K. S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street MS 42, Cambridge, MA 02138 (United States); Bullock, E. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Dowell, C. D. [Jet Propulsion Laboratory, Pasadena, CA 91109 (United States); Duband, L. [SBT, Commissariat à l’Energie Atomique, Grenoble (France); Fliescher, S. [Department of Physics, University of Minnesota, Minneapolis, MN 55455 (United States); Halpern, M.; Hasselfield, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC (Canada); Hilton, G. C.; Irwin, K. D., E-mail: csheehy@uchicago.edu [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Collaboration: Bicep2 Collaboration; and others

2015-12-01

In a companion paper, we have reported a >5σ detection of degree scale B-mode polarization at 150 GHz by the Bicep2 experiment. Here we provide a detailed study of potential instrumental systematic contamination to that measurement. We focus extensively on spurious polarization that can potentially arise from beam imperfections. We present a heuristic classification of beam imperfections according to their symmetries and uniformities, and discuss how resulting contamination adds or cancels in maps that combine observations made at multiple orientations of the telescope about its boresight axis. We introduce a technique, which we call “deprojection,” for filtering the leading order beam-induced contamination from time-ordered data, and show that it reduces power in Bicep2's actual and null-test BB spectra consistent with predictions using high signal-to-noise beam shape measurements. We detail the simulation pipeline that we use to directly simulate instrumental systematics and the calibration data used as input to that pipeline. Finally, we present the constraints on BB contamination from individual sources of potential systematics. We find that systematics contribute BB power that is a factor of ∼10× below Bicep2's three-year statistical uncertainty, and negligible compared to the observed BB signal. The contribution to the best-fit tensor/scalar ratio is at a level equivalent to r = (3–6) × 10{sup −3}.

Bicep2. III. INSTRUMENTAL SYSTEMATICS

International Nuclear Information System (INIS)

Ade, P. A. R.; Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Filippini, J. P.; Golwala, S. R.; Hildebrandt, S. R.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Buder, I.; Karkare, K. S.; Bullock, E.; Dowell, C. D.; Duband, L.; Fliescher, S.; Halpern, M.; Hasselfield, M.; Hilton, G. C.; Irwin, K. D.

2015-01-01

In a companion paper, we have reported a >5σ detection of degree scale B-mode polarization at 150 GHz by the Bicep2 experiment. Here we provide a detailed study of potential instrumental systematic contamination to that measurement. We focus extensively on spurious polarization that can potentially arise from beam imperfections. We present a heuristic classification of beam imperfections according to their symmetries and uniformities, and discuss how resulting contamination adds or cancels in maps that combine observations made at multiple orientations of the telescope about its boresight axis. We introduce a technique, which we call “deprojection,” for filtering the leading order beam-induced contamination from time-ordered data, and show that it reduces power in Bicep2's actual and null-test BB spectra consistent with predictions using high signal-to-noise beam shape measurements. We detail the simulation pipeline that we use to directly simulate instrumental systematics and the calibration data used as input to that pipeline. Finally, we present the constraints on BB contamination from individual sources of potential systematics. We find that systematics contribute BB power that is a factor of ∼10× below Bicep2's three-year statistical uncertainty, and negligible compared to the observed BB signal. The contribution to the best-fit tensor/scalar ratio is at a level equivalent to r = (3–6) × 10 −3

Calibration of the Herschel SPIRE Fourier Transform Spectrometer

OpenAIRE

Swinyard, Bruce; Polehampton, E. T.; Hopwood, R.; Valtchanov, I.; Lu, N.; Fulton, T.; Benielli, D.; Imhof, P.; Marchili, N.; Baluteau, J.- P.; Bendo, G. J.; Ferlet, M.; Griffin, Matthew Jason; Lim, T. L.; Makiwa, G.

2014-01-01

The Herschel Spectral and Photometric REceiver (SPIRE) instrument consists of an imaging photometric camera and an imaging Fourier Transform Spectrometer (FTS), both operating over a frequency range of ∼450–1550 GHz. In this paper, we briefly review the FTS design, operation, and data reduction, and describe in detail the approach taken to relative calibration (removal of instrument signatures) and absolute calibration against standard astronomical sources. The calibration scheme assumes a sp...

Calibration of the DLP-SC-3300-02 probe

DEFF Research Database (Denmark)

Pivnenko, Sergey; Breinbjerg, Olav

This report douments the calibration measurement of the DLP-SC-3300-02 dual-linearly polarized near-field probe. The measurement comprises radiation pattern, diretivity, gain, spetra of spherial wave coefients, polarization charateristis, and complex channel balance at 41 frequencies, as well...

Acceleration of polarized particles

International Nuclear Information System (INIS)

Buon, J.

1992-05-01

The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

Calibration of the DSCOVR EPIC Visible and NIR Channels using MODIS Terra and Aqua Data and EPIC Lunar Observations

Science.gov (United States)

Geogdzhayev, Igor V.; Marshak, Alexander

2018-01-01

The unique position of the Deep Space Climate Observatory (DSCOVR) Earth Polychromatic Imaging Camera (EPIC) at the Lagrange 1 point makes an important addition to the data from currently operating low Earth orbit observing instruments. EPIC instrument does not have an onboard calibration facility. One approach to its calibration is to compare EPIC observations to the measurements from polar-orbiting radiometers. Moderate Resolution Imaging Spectroradiometer (MODIS) is a natural choice for such comparison due to its well-established calibration record and wide use in remote sensing. We use MODIS Aqua and Terra L1B 1km reflectances to infer calibration coefficients for four EPIC visible and NIR channels: 443, 551, 680 and 780 nm. MODIS and EPIC measurements made between June 2015 and 2016 are employed for comparison. We first identify favorable MODIS pixels with scattering angle matching temporarily collocated EPIC observations. Each EPIC pixel is then spatially collocated to a subset of the favorable MODIS pixels within 25 km radius. Standard deviation of the selected MODIS pixels as well as of the adjacent EPIC pixels is used to find the most homogeneous scenes. These scenes are then used to determine calibration coefficients using a linear regression between EPIC counts/sec and reflectances in the close MODIS spectral channels. We present thus inferred EPIC calibration coefficients and discuss sources of uncertainties. The lunar EPIC observations are used to calibrate EPIC O2 absorbing channels (688 and 764 nm), assuming that there is a small difference between moon reflectances separated by approx.10 nm in wavelength provided the calibration factors of the red (680 nm) and near-IR (780 nm) are known from comparison between EPIC and MODIS.

Gamma counter calibration system

International Nuclear Information System (INIS)

1977-01-01

A method and apparatus are described for the calibration of a gamma radiation measurement instrument to be used over any of a number of different absolute energy ranges. The method includes the steps of adjusting the overall signal gain associated with pulses which are derived from detected gamma rays, until the instrument is calibrated for a particular absolute energy range; then storing parameter settings corresponding to the adjusted overall signal gain, and repeating the process for other desired absolute energy ranges. The stored settings can be subsequently retrieved and reapplied so that test measurements can be made using a selected one of the absolute energy ranges. Means are provided for adjusting the overall signal gain and a specific technique is disclosed for making coarse, then fine adjustments to the signal gain, for rapid convergence of the required calibration settings. (C.F.)

Calibration of personal dosimeters: Quantities and terminology

International Nuclear Information System (INIS)

Aleinikov, V.E.

1999-01-01

The numerical results obtained in the interpretation of individual monitoring of external radiation depend not only on the accurate calibration of the radiation measurement instruments involved, but also on the definition of the quantities in term of which these instruments are calibrated The absence of uniformity in terminology not only makes it difficult to understand properly the scientific and technical literature but can also lead to incorrect interpretation of particular concepts and recommendations. In this paper, brief consideration is given to definition of radiation quantities and terminology used in calibration procedures. (author)

Limits on the Secular Drift of the TMI Calibration

Science.gov (United States)

Wilheit, T. T.; Farrar, S.; Jones, L.; Santos-Garcia, A.

2012-12-01

Data from the TRMM Microwave Imager (TMI) can be applied to the problem of determining the trend in oceanic precipitation over more than a decade. It is thus critical to know if the calibration of the instrument has any drift over this time scale. Recently a set of Windsat data with a self-consistent calibration covering July 2005 through June of 2006 and all of 2011 has become available. The mission of Windsat, determining the feasibility of measuring oceanic wind speed and direction, requires extraordinary attention to instrument calibration. With TRMM being in a low inclination orbit and Windsat in a near polar sun synchronous orbit, there are many observations coincident in space and nearly coincident in time. A data set has been assembled where the observations are averaged over 1 degree boxes of latitude and longitude and restricted to a maximum of 1 hour time difference. University of Central Florida (UCF) compares the two radiometers by computing radiances based on Global Data Assimilation System (GDAS) analyses for all channels of each radiometer for each box and computing double differences for corresponding channels. The algorithm is described in detail by Biswas et al., (2012). Texas A&M (TAMU) uses an independent implementation of GDAS-based algorithm and another where the radiances of Windsat are used to compute Sea Surface Temperature, Sea Surface Wind Speed, Precipitable Water and Cloud Liquid Water for each box. These are, in turn, used to compute the TMI radiances. These two algorithms have been described in detail by Wilheit (2012). Both teams apply stringent filters to the boxes to assure that the conditions are consistent with the model assumptions. Examination of both teams' results indicates that the drift is less than 0.04K over the 5 ½ year span for the 10 and 37 GHz channels of TMI. The 19 and 21 GHz channels have somewhat larger differences, but they are more influenced by atmospheric changes. Given the design of the instruments, it is

Conception of the Instrument Calibration Laboratory of Ionizing Radiation Measurement (LACIMRI) of CTMSP - Sao Paulo, SP; Concepcao do Laboratorio de Calibracao de Instrumentos de Medicao de Radiacao Ionizante (LACIMRI) do CTMSP, Sao Paulo, SP

Energy Technology Data Exchange (ETDEWEB)

Silva, Raimundo Dias da; Kibrit, Eduardo, E-mail: raimundo@ctmsp.mar.mil.b, E-mail: kibrit@ctmsp.mar.mil.b [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil)

2009-07-01

The present work describes the phases of implantation of calibration laboratory of ionizing radiation measurement instruments at the CTMSP, Sao Paulo, in a priory approved by CNEN, Brazil. That laboratory will allow and enhance the present metrological capacity for the attendance to the growing demand for calibration services of the instruments

The Atacama Cosmology Telescope: The Polarization-Sensitive ACTPol Instrument

Science.gov (United States)

Thornton, R. J.; Ade, P. A. R.; Aiola, S.; Angile, F. E.; Amiri, M.; Beall, J. A.; Becker, D. T.; Cho, H.-M.; Choi, S. K.; Corlies, P.;

The Atacama Cosmology Telescope: The Polarization-sensitive ACTPol Instrument

Science.gov (United States)

Thornton, R. J.; Ade, P. A. R.; Aiola, S.; Angilè, F. E.; Amiri, M.; Beall, J. A.; Becker, D. T.; Cho, H.-M.; Choi, S. K.; Corlies, P.; Coughlin, K. P.; Datta, R.; Devlin, M. J.; Dicker, S. R.; Dünner, R.; Fowler, J. W.; Fox, A. E.; Gallardo, P. A.; Gao, J.; Grace, E.; Halpern, M.; Hasselfield, M.; Henderson, S. W.; Hilton, G. C.; Hincks, A. D.; Ho, S. P.; Hubmayr, J.; Irwin, K. D.; Klein, J.; Koopman, B.; Li, Dale; Louis, T.; Lungu, M.; Maurin, L.; McMahon, J.; Munson, C. D.; Naess, S.; Nati, F.; Newburgh, L.; Nibarger, J.; Niemack, M. D.; Niraula, P.; Nolta, M. R.; Page, L. A.; Pappas, C. G.; Schillaci, A.; Schmitt, B. L.; Sehgal, N.; Sievers, J. L.; Simon, S. M.; Staggs, S. T.; Tucker, C.; Uehara, M.; van Lanen, J.; Ward, J. T.; Wollack, E. J.

2016-12-01

The Atacama Cosmology Telescope (ACT) makes high angular resolution measurements of anisotropies in the Cosmic Microwave Background (CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3° field of view, 100 mK cryogenics with continuous cooling, and meta material antireflection coatings. ACTPol comprises three arrays with separate cryogenic optics: two arrays at a central frequency of 148 GHz and one array operating simultaneously at both 97 GHz and 148 GHz. The combined instrument sensitivity, angular resolution, and sky coverage are optimized for measuring angular power spectra, clusters via the thermal Sunyaev–Zel’dovich (SZ) and kinetic SZ signals, and CMB lensing due to large-scale structure. The receiver was commissioned with its first 148 GHz array in 2013, observed with both 148 GHz arrays in 2014, and has recently completed its first full season of operations with the full suite of three arrays. This paper provides an overview of the design and initial performance of the receiver and related systems.

Onboard calibration igneous targets for the Mars Science Laboratory Curiosity rover and the Chemistry Camera laser induced breakdown spectroscopy instrument

Energy Technology Data Exchange (ETDEWEB)

Fabre, C., E-mail: cecile.fabre@g2r.uhp-nancy.fr [G2R, Nancy Universite (France); Maurice, S.; Cousin, A. [IRAP, Toulouse (France); Wiens, R.C. [LANL, Los Alamos, NM (United States); Forni, O. [IRAP, Toulouse (France); Sautter, V. [MNHN, Paris (France); Guillaume, D. [GET, Toulouse (France)

2011-03-15

Accurate characterization of the Chemistry Camera (ChemCam) laser-induced breakdown spectroscopy (LIBS) on-board composition targets is of prime importance for the ChemCam instrument. The Mars Science Laboratory (MSL) science and operations teams expect ChemCam to provide the first compositional results at remote distances (1.5-7 m) during the in situ analyses of the Martian surface starting in 2012. Thus, establishing LIBS reference spectra from appropriate calibration standards must be undertaken diligently. Considering the global mineralogy of the Martian surface, and the possible landing sites, three specific compositions of igneous targets have been determined. Picritic, noritic, and shergottic glasses have been produced, along with a Macusanite natural glass. A sample of each target will fly on the MSL Curiosity rover deck, 1.56 m from the ChemCam instrument, and duplicates are available on the ground. Duplicates are considered to be identical, as the relative standard deviation (RSD) of the composition dispersion is around 8%. Electronic microprobe and laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) analyses give evidence that the chemical composition of the four silicate targets is very homogeneous at microscopic scales larger than the instrument spot size, with RSD < 5% for concentration variations > 0.1 wt.% using electronic microprobe, and < 10% for concentration variations > 0.01 wt.% using LA ICP-MS. The LIBS campaign on the igneous targets performed under flight-like Mars conditions establishes reference spectra for the entire mission. The LIBS spectra between 240 and 900 nm are extremely rich, hundreds of lines with high signal-to-noise, and a dynamical range sufficient to identify unambiguously major, minor and trace elements. For instance, a first LIBS calibration curve has been established for strontium from [Sr] = 284 ppm to [Sr] = 1480 ppm, showing the potential for the future calibrations for other major or minor

Onboard calibration igneous targets for the Mars Science Laboratory Curiosity rover and the Chemistry Camera laser induced breakdown spectroscopy instrument

International Nuclear Information System (INIS)

Fabre, C.; Maurice, S.; Cousin, A.; Wiens, R.C.; Forni, O.; Sautter, V.; Guillaume, D.

2011-01-01

Accurate characterization of the Chemistry Camera (ChemCam) laser-induced breakdown spectroscopy (LIBS) on-board composition targets is of prime importance for the ChemCam instrument. The Mars Science Laboratory (MSL) science and operations teams expect ChemCam to provide the first compositional results at remote distances (1.5-7 m) during the in situ analyses of the Martian surface starting in 2012. Thus, establishing LIBS reference spectra from appropriate calibration standards must be undertaken diligently. Considering the global mineralogy of the Martian surface, and the possible landing sites, three specific compositions of igneous targets have been determined. Picritic, noritic, and shergottic glasses have been produced, along with a Macusanite natural glass. A sample of each target will fly on the MSL Curiosity rover deck, 1.56 m from the ChemCam instrument, and duplicates are available on the ground. Duplicates are considered to be identical, as the relative standard deviation (RSD) of the composition dispersion is around 8%. Electronic microprobe and laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) analyses give evidence that the chemical composition of the four silicate targets is very homogeneous at microscopic scales larger than the instrument spot size, with RSD 0.1 wt.% using electronic microprobe, and 0.01 wt.% using LA ICP-MS. The LIBS campaign on the igneous targets performed under flight-like Mars conditions establishes reference spectra for the entire mission. The LIBS spectra between 240 and 900 nm are extremely rich, hundreds of lines with high signal-to-noise, and a dynamical range sufficient to identify unambiguously major, minor and trace elements. For instance, a first LIBS calibration curve has been established for strontium from [Sr] = 284 ppm to [Sr] = 1480 ppm, showing the potential for the future calibrations for other major or minor elements.

An Investigation of a Novel Cross-Calibration Method of FY-3C/VIRR against NPP/VIIRS in the Dunhuang Test Site

Directory of Open Access Journals (Sweden)

Caixia Gao

2016-01-01

Full Text Available Radiometric cross-calibration of Earth observation sensors is an effective approach to evaluate instrument calibration performance, identify and diagnose calibration anomalies, and quantify the consistency of measurements from different sensors. In this study a novel cross-calibration method is proposed, taking into account the spectral and viewing angle differences adequately; the method is applied to the FY-3C/Visible Infrared Radiometer (VIRR, taking the Suomi National Polar-Orbiting Partnership (NPP/Visible Infrared Imaging Radiometer Suite (VIIRS as a reference. The results show that the relative difference between the two sets increases from January to May 2014, and becomes lower for the data on 24 July, 11 September, and 16 September, within approximately 10%. This phenomenon is caused by the updating of the calibration coefficients in the VIRR datasets with results from a vicarious method on June 2014. After performing an approximate estimation of the uncertainty, it is demonstrated that this calibration has a total uncertainty of 5.5%–6.0%, which is mainly from the uncertainty of the Bidirectional Reflectance Distribution Function model.

Development of a calibration methodology for instruments used to interventional radiology quality control

International Nuclear Information System (INIS)

Miranda, Jurema Aparecida de

2009-01-01

Interventional radiology is the technique where X radiation images are used as a tool in the conduction of diagnostic or/and therapeutic procedures. The exposition times are long for both procedures, diagnostic and therapeutic, may cause serious injuries in the patient, and also contribute to the dose of the clinical staff. In Brazil there are not yet well established rules to determine the doses and to make the dosimetry in fluoroscopic beams. There is great interest in this study, in relation to the beam quality, the half-value-layer, and others parameters. In this work a Medicor Neo Diagnomax clinical X ray generator, fluoroscopy mode, was used to develop a calibration methodology for instruments used in interventional radiology quality control. One plane parallel ionization chamber PTW was used as monitor. The ionization chambers recommended for fluoroscopy measurements had been evaluated and calibrated in relation to the IPEN Calibration Laboratory reference ionization chamber. The RQR3, RQR5 and RQR7 radiation qualities and the specific ones for fluoroscopy, RQC3, RQC5 and RQC7, were established following the norm IEC 61267. All beams characteristics were determined. Ionization chambers positioning system and the acrylic phantoms to the entrance and exit doses determination were developed and constructed. The results obtained show air kerma rates of 4.5x10 -3 , 1.2x10 -2 and 1.9x10 -2 Gy/min for RQC3, RQC5 and RQC7 respectively. Tests with and without the collimation just after the monitor chamber, were carried out and the results showed a difference of +5.5%, +0.6% e + 0.8%, confirming the importance of the collimation use in these interventionist procedures. (author)

A water flow calorimeter calibration system

International Nuclear Information System (INIS)

Ullrich, F.T.

1983-01-01

Neutral beam systems are instrumented by several water flow calorimeter systems, and some means is needed to verify the accuracy of such systems and diagnose their failures. This report describes a calibration system for these calorimeters. The calibrator consists of two 24 kilowatt circulation water heaters, with associated controls and instrumentation. The unit can supply power from 0 to 48 kW in five coarse steps and one fine range. Energy is controlled by varying the power and the time of operation of the heaters. The power is measured by means of precision power transducers, and the energy is measured by integrating the power with respect to time. The accuracy of the energy measurement is better than 0.5% when the power supplied is near full scale, and the energy resolution is better than 1 kilojoule. The maximum energy delivered is approximately 50 megajoules. The calorimetry loop to be calibrated is opened, and the calibrator is put in series with the calorimeter heat source. The calorimeter is then operated in its normal fashion, with the calibrator used as the heat source. The calibrator can also be used in a stand alone mode to calibrate calorimeter sensors removed from systems

Estimation of photon energy distribution in gamma calibration field

International Nuclear Information System (INIS)

Takahashi, Fumiaki; Shimizu, Shigeru; Yamaguchi, Yasuhiro

1997-03-01

Photon survey instruments used for radiation protection are usually calibrated at gamma radiation fields, which are traceable to the national standard with regard to exposure. Whereas scattered radiations as well as primary gamma-rays exit in the calibration field, no consideration for the effect of the scattered radiations on energy distribution is given in routine calibration works. The scattered radiations can change photon energy spectra in the field, and this can result in misinterpretations of energy-dependent instrument responses. Construction materials in the field affect the energy distribution and magnitude of the scattered radiations. The geometric relationship between a gamma source and an instrument can determine the energy distribution at the calibration point. Therefore, it is essential for the assurance of quality calibration to estimate the energy spectra at the gamma calibration fields. Then, photon energy distributions at some fields in the Facility of Radiation Standard of the Japan Atomic Energy Research Institute (JAERI) were estimated by measurements using a NaI(Tl) detector and Monte Carlo calculations. It was found that the use of collimator gives a different feature in photon energy distribution. The origin of scattered radiations and the ratio of the scattered radiations to the primary gamma-rays were obtained. The results can help to improve the calibration of photon survey instruments in the JAERI. (author)

The QUIET Instrument

Energy Technology Data Exchange (ETDEWEB)

Bischoff, C.; et al.

2012-07-01

The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the Cosmic Microwave Background, targeting the imprint of inflationary gravitational waves at large angular scales ({approx}1{sup o}). Between 2008 October and 2010 December, two independent receiver arrays were deployed sequentially on a 1.4m side-fed Dragonian telescope. The polarimeters which form the focal planes use a highly compact design based on High Electron Mobility Transistors (HEMTs) that provides simultaneous measurements of the Stokes parameters Q, U, and I in a single module. The 17-element Q-band polarimeter array, with a central frequency of 43.1 GHz, has the best sensitivity (69 {mu}Ks{sup 1/2}) and the lowest instrumental systematic errors ever achieved in this band, contributing to the tensor-to-scalar ratio at r < 0:1. The 84-element W-band polarimeter array has a sensitivity of 87 {mu}Ks{sup 1/2} at a central frequency of 94.5 GHz. It has the lowest systematic errors to date, contributing at r < 0:01. The two arrays together cover multipoles in the range {ell} {approx} 25 -- 975. These are the largest HEMT-based arrays deployed to date. This article describes the design, calibration, performance of, and sources of systematic error for the instrument.

Calibration and uncertainty in electromagnetic fields measuring methods

International Nuclear Information System (INIS)

Anglesio, L.; Crotti, G.; Borsero, M.; Vizio, G.

1999-01-01

Calibration and reliability in electromagnetic field measuring methods are assured by calibration of measuring instruments. In this work are illustrated systems for generation of electromagnetic fields at low and high frequency, calibration standard and accuracy [it

Recommended inorganic chemicals for calibration

International Nuclear Information System (INIS)

Moody, J.R.; Greenberg, R.R.; Pratt, K.W.; Rains, T.C.

1988-01-01

All analytical techniques depend on the use of calibration chemicals to relate analyte concentration to an instrumental parameter. A fundamental component in the preparation of calibration solutions is the weighing of a pure chemical or metal before preparing a solution standard. The analyst must be assured that the purity, stoichiometry, and assay of the chemical are known. These terms have different meanings, and each has an important influence. This report is intended to assist the analyst in the selection and use of chemical standards for instrumental calibration. Purity, stoichiometry, and preparation of solutions for different purposes are discussed, and a critical evaluation of the best materials available for each element is presented for use in preparing solutions or calibration standards. Information on the chemical form, source, purity, drying, and appropriate precautions is given. In some cases, multiple sources or chemical forms are available. Certain radioactive elements, the transuranic elements, and the noble gases are not considered

Calibrate the aerial surveying instrument by the limited surface source and the single point source that replace the unlimited surface source

International Nuclear Information System (INIS)

Lu Cunheng

1999-01-01

It is described that the calculating formula and surveying result is found on the basis of the stacking principle of gamma ray and the feature of hexagonal surface source when the limited surface source replaces the unlimited surface source to calibrate the aerial survey instrument on the ground, and that it is found in the light of the exchanged principle of the gamma ray when the single point source replaces the unlimited surface source to calibrate aerial surveying instrument in the air. Meanwhile through the theoretical analysis, the receiving rate of the crystal bottom and side surfaces is calculated when aerial surveying instrument receives gamma ray. The mathematical expression of the gamma ray decaying following height according to the Jinge function regularity is got. According to this regularity, the absorbing coefficient that air absorbs the gamma ray and the detective efficiency coefficient of the crystal is calculated based on the ground and air measuring value of the bottom surface receiving count rate (derived from total receiving count rate of the bottom and side surface). Finally, according to the measuring value, it is proved that imitating the change of total receiving gamma ray exposure rate of the bottom and side surfaces with this regularity in a certain high area is feasible

Error-in-variables models in calibration

Science.gov (United States)

Lira, I.; Grientschnig, D.

2017-12-01

In many calibration operations, the stimuli applied to the measuring system or instrument under test are derived from measurement standards whose values may be considered to be perfectly known. In that case, it is assumed that calibration uncertainty arises solely from inexact measurement of the responses, from imperfect control of the calibration process and from the possible inaccuracy of the calibration model. However, the premise that the stimuli are completely known is never strictly fulfilled and in some instances it may be grossly inadequate. Then, error-in-variables (EIV) regression models have to be employed. In metrology, these models have been approached mostly from the frequentist perspective. In contrast, not much guidance is available on their Bayesian analysis. In this paper, we first present a brief summary of the conventional statistical techniques that have been developed to deal with EIV models in calibration. We then proceed to discuss the alternative Bayesian framework under some simplifying assumptions. Through a detailed example about the calibration of an instrument for measuring flow rates, we provide advice on how the user of the calibration function should employ the latter framework for inferring the stimulus acting on the calibrated device when, in use, a certain response is measured.

Computational integration of the phases and procedures of calibration processes for radioprotection

International Nuclear Information System (INIS)

Santos, Gleice R. dos; Thiago, Bibiana dos S.; Rocha, Felicia D.G.; Santos, Gelson P. dos; Potiens, Maria da Penha A.; Vivolo, Vitor

2011-01-01

This work proceed the computational integration of the processes phases by using only a single computational software, from the entrance of the instrument at the Instrument Calibration Laboratory (LCI-IPEN) to the conclusion of calibration procedures. So, the initial information such as trade mark, model, manufacturer, owner, and the calibration records are digitized once until the calibration certificate emission

Sentinel-5: the new generation European operational atmospheric chemistry mission in polar orbit

Science.gov (United States)

Pérez Albiñana, Abelardo; Erdmann, Matthias; Wright, Norrie; Martin, Didier; Melf, Markus; Bartsch, Peter; Seefelder, Wolfgang

2017-08-01

Sentinel-5 is an Earth Observation instrument to be flown on the Metop Second Generation (Metop-SG) satellites with the fundamental objective of monitoring atmospheric composition from polar orbit. The Sentinel-5 instrument consists of five spectrometers to measure the solar spectral radiance backscattered by the earth atmosphere in five bands within the UV (270nm) to SWIR (2385nm) spectral range. Data provided by Sentinel-5 will allow obtaining the distribution of important atmospheric constituents such as ozone, on a global daily basis and at a finer spatial resolution than its precursor instruments on the first generation of Metop satellites. The launch of the first Metop-SG satellite is foreseen for 2021. The Sentinel-5 instrument is being developed by Airbus DS under contract to the European Space Agency. The Sentinel-5 mission is part of the Space Component of the Copernicus programme, a joint initiative by ESA, EUMETSAT and the European Commission. The Preliminary Design Review (PDR) for the Sentinel-5 development was successfully completed in 2015. This paper provides a description of the Sentinel-5 instrument design and data calibration.

Evaluation of VIIRS and MODIS Thermal Emissive Band Calibration Stability Using Ground Target

Directory of Open Access Journals (Sweden)

Sriharsha Madhavan

2016-02-01

Full Text Available The S-NPP Visible Infrared Imaging Radiometer Suite (VIIRS instrument, a polar orbiting Earth remote sensing instrument built using a strong MODIS background, employs a similarly designed on-board calibrating source—a V-grooved blackbody for the Thermal Emissive Bands (TEB. The central wavelengths of most VIIRS TEBs are very close to those of MODIS with the exception of the 10.7 µm channel. To ensure the long term continuity of climate data records derived using VIIRS and MODIS TEB, it is necessary to assess any systematic differences between the two instruments, including scenes with temperatures significantly lower than blackbody operating temperatures at approximately 290 K. Previous work performed by the MODIS Characterization Support Team (MCST at NASA/GSFC used the frequent observations of the Dome Concordia site located in Antarctica to evaluate the calibration stability and consistency of Terra and Aqua MODIS over the mission lifetime. The near-surface temperature measurements from an automatic weather station (AWS provide a direct reference useful for tracking the stability and determining the relative bias between the two MODIS instruments. In this study, the same technique is applied to the VIIRS TEB and the results are compared with those from the matched MODIS TEB. The results of this study show a small negative bias when comparing the matching VIIRS and Aqua MODIS TEB, implying a higher brightness temperature for S-VIIRS at the cold end. Statistically no significant drift is observed for VIIRS TEB performance over the first 3.5 years of the mission.

Compact radiometric microwave calibrator

International Nuclear Information System (INIS)

Fixsen, D. J.; Wollack, E. J.; Kogut, A.; Limon, M.; Mirel, P.; Singal, J.; Fixsen, S. M.

2006-01-01

The calibration methods for the ARCADE II instrument are described and the accuracy estimated. The Steelcast coated aluminum cones which comprise the calibrator have a low reflection while maintaining 94% of the absorber volume within 5 mK of the base temperature (modeled). The calibrator demonstrates an absorber with the active part less than one wavelength thick and only marginally larger than the mouth of the largest horn and yet black (less than -40 dB or 0.01% reflection) over five octaves in frequency

Astronomy in Denver: Probing Interstellar Circular Polarization with Polvis, a Full Stokes Single Shot Polarimeter

Science.gov (United States)

Wolfe, Tristan; Stencel, Robert E.

2018-06-01

Measurements of optical circular polarization (Stokes V) introduced by dust grains in the ISM are important for two main reasons. First of all, the polarization itself contains information about the metallic versus dielectric composition of the dust grains themselves (H. C. van de Hulst 1957, textbook). Additionally, circular polarization can help constrain the interstellar component of the polarization of any source that may have intrinsic polarization, which needs to be calibrated for astrophysical study. Though interstellar circular polarization has been observed (P. G. Martin 1972, MNRAS 159), most broadband measurements of ISM polarization include linear polarization only (Stokes Q and U), due to the relatively low circular polarization signal and the added instrumentation complexity of including V-measurement capability. Prior circular polarization measurements have also received very little follow-up in the past several decades, even as polarimeters have become more accurate due to advances in technology. The University of Denver is pursuing these studies with POLVIS, a prototype polarimeter that utilizes a stress-engineered optic ("SEO", A. K. Spilman and T. G. Brown 2007, Applied Optics IP 46) to produce polarization-dependent PSFs (A. M. Beckley and T. G. Brown 2010, Proc SPIE 7570). These PSFs are analyzed to provide simultaneous Stokes I, Q, U, and V measurements, in a single beam and single image, along the line-of-sight to point source-like objects. Polvis is the first polarimeter to apply these optics and measurement techniques for astronomical observations. We present the first results of this instrument in B, V, and R wavebands, providing a fresh look at full Stokes interstellar polarization. Importantly, this set of efforts will constrain the ISM contribution to the polarization with respect to intrinsic stellar components. The authors are grateful to the estate of William Herschel Womble for the support of astronomy at the University of Denver

CryoSat-2 SIRAL Calibration and Performance

Science.gov (United States)

Fornari, M.; Scagliola, M.; Tagliani, N.; Parrinello, T.

2012-12-01

The main payload of CryoSat-2 is a Ku band pulse-width limited radar altimeter, called SIRAL (Synthetic interferometric radar altimeter), that transmits pulses at a high pulse repetition frequency thus making the received echoes phase coherent and suitable for azimuth processing. This allows to reach an along track resolution of about 250 meters which is a significant improvement over traditional pulse-width limited altimeters. Due to the fact that SIRAL is a phase coherent pulse-width limited radar altimeter, a proper calibration approach has been developed, including both an internal and external calibration. The internal calibration monitors the instrument impulse response and the transfer function, like traditional altimeters. In addition to that, the interferometer requires a special calibration developed ad hoc for SIRAL. The external calibration is performed with the use of a ground transponder, located in Svalbard, which receives SIRAL signal and sends the echo back to the satellite. Internal calibration data are processed on ground by the CryoSat-2 Instrument Processing Facility (IPF1) and then applied to the science data. In December 2012, two and a half years of calibration data will be available, which will be shown in this poster. The external calibration (transponder) data are processed and analyzed independently from the operational chain. The use of an external transponder has been very useful to determine instrument performance and for the tuning of the on-ground processor. This poster presents the transponder results in terms of range noise and datation error.

Stochastic Modeling and Generation of Partially Polarized or Partially Coherent Electromagnetic Waves

Science.gov (United States)

Davis, Brynmor; Kim, Edward; Piepmeier, Jeffrey; Hildebrand, Peter H. (Technical Monitor)

2001-01-01

Many new Earth remote-sensing instruments are embracing both the advantages and added complexity that result from interferometric or fully polarimetric operation. To increase instrument understanding and functionality a model of the signals these instruments measure is presented. A stochastic model is used as it recognizes the non-deterministic nature of any real-world measurements while also providing a tractable mathematical framework. A stationary, Gaussian-distributed model structure is proposed. Temporal and spectral correlation measures provide a statistical description of the physical properties of coherence and polarization-state. From this relationship the model is mathematically defined. The model is shown to be unique for any set of physical parameters. A method of realizing the model (necessary for applications such as synthetic calibration-signal generation) is given and computer simulation results are presented. The signals are constructed using the output of a multi-input multi-output linear filter system, driven with white noise.

Traceability of radiation protection instruments

Science.gov (United States)

Hino, Y.; Kurosawa, T.

2007-08-01

Radiation protection instruments are used in daily measurement of dose and activities in workplaces and environments for safety management. The requirements for calibration certificates with traceability are increasing for these instruments to ensure the consistency and reliabilities of the measurement results. The present traceability scheme of radiation protection instruments for dose and activity measurements is described with related IEC/ISO requirements. Some examples of desirable future calibration systems with recent new technologies are also discussed to establish the traceability with reasonable costs and reliabilities.

A new method for the precise absolute calibration of polarization effects in spin-1/2-spin-0 scattering applied to p-. alpha. scattering at 25. 68 MeV and. theta. sub lab =117. 5 sup 0

Energy Technology Data Exchange (ETDEWEB)

Clajus, M.; Egun, P.; Grueebler, W.; Hautle, P.; Weber, A. (Eidgenoessische Technische Hochschule, Zurich (Switzerland). Inst. fuer Mittelenergiephysik); Schmelzbach, P.A. (Paul Scherrer Inst., Villigen (Switzerland)); Kretschmer, W.; Haller, M.; Prenzel, C.J.; Rauscher, A.; Schuster, W.; Weidmann, R. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Physikalisches Inst.)

1989-08-20

A new general method for the precise calibration of beam polarization or analyzing power in spin-1/2-spin-0 elastic scattering has been developed. This absolute calibration method uses the double scattering technique in connection with modern polarized ion source technology. It is based on an incident beam with at least two different polarization states and its independent of beam energy and scattering angle. The application to p-{alpha} elastic scattering at 25.68 MeV and a lab. angle of 117.5{sup 0} is described. The result is a new determination of the analyzing power to an accuracy of better than 1%, i.e. A{sub y}=0.8119+-0.0076. Systematic errors are extensively discussed. (orig.).

Calibration of the DSCOVR EPIC visible and NIR channels using MODIS Terra and Aqua data and EPIC lunar observations

Directory of Open Access Journals (Sweden)

I. V. Geogdzhayev

2018-01-01

Full Text Available The unique position of the Deep Space Climate Observatory (DSCOVR Earth Polychromatic Imaging Camera (EPIC at the Lagrange 1 point makes an important addition to the data from currently operating low Earth orbit observing instruments. EPIC instrument does not have an onboard calibration facility. One approach to its calibration is to compare EPIC observations to the measurements from polar-orbiting radiometers. Moderate Resolution Imaging Spectroradiometer (MODIS is a natural choice for such comparison due to its well-established calibration record and wide use in remote sensing. We use MODIS Aqua and Terra L1B 1 km reflectances to infer calibration coefficients for four EPIC visible and NIR channels: 443, 551, 680 and 780 nm. MODIS and EPIC measurements made between June 2015 and 2016 are employed for comparison. We first identify favorable MODIS pixels with scattering angle matching temporarily collocated EPIC observations. Each EPIC pixel is then spatially collocated to a subset of the favorable MODIS pixels within 25 km radius. Standard deviation of the selected MODIS pixels as well as of the adjacent EPIC pixels is used to find the most homogeneous scenes. These scenes are then used to determine calibration coefficients using a linear regression between EPIC counts s−1 and reflectances in the close MODIS spectral channels. We present thus inferred EPIC calibration coefficients and discuss sources of uncertainties. The lunar EPIC observations are used to calibrate EPIC O2 absorbing channels (688 and 764 nm, assuming that there is a small difference between moon reflectances separated by  ∼  10 nm in wavelength and provided the calibration factors of the red (680 nm and NIR (780 nm are known from comparison between EPIC and MODIS.

An automated calibration laboratory for flight research instrumentation: Requirements and a proposed design approach

Science.gov (United States)

Oneill-Rood, Nora; Glover, Richard D.

1990-01-01

NASA's Dryden Flight Research Facility (Ames-Dryden), operates a diverse fleet of research aircraft which are heavily instrumented to provide both real time data for in-flight monitoring and recorded data for postflight analysis. Ames-Dryden's existing automated calibration (AUTOCAL) laboratory is a computerized facility which tests aircraft sensors to certify accuracy for anticipated harsh flight environments. Recently, a major AUTOCAL lab upgrade was initiated; the goal of this modernization is to enhance productivity and improve configuration management for both software and test data. The new system will have multiple testing stations employing distributed processing linked by a local area network to a centralized database. The baseline requirements for the new AUTOCAL lab and the design approach being taken for its mechanization are described.

The Geostationary Lightning Mapper: Its Performance and Calibration

Science.gov (United States)

Christian, H. J., Jr.

2015-12-01

The Geostationary Lightning Mapper (GLM) has been developed to be an operational instrument on the GOES-R series of spacecraft. The GLM is a unique instrument, unlike other meteorological instruments, both in how it operates and in the information content that it provides. Instrumentally, it is an event detector, rather than an imager. While processing almost a billion pixels per second with 14 bits of resolution, the event detection process reduces the required telemetry bandwidth by almost 105, thus keeping the telemetry requirements modest and enabling efficient ground processing that leads to rapid data distribution to operational users. The GLM was designed to detect about 90 percent of the total lightning flashes within its almost hemispherical field of view. Based on laboratory calibration, we expect the on-orbit detection efficiency to be closer to 85%, making it the highest performing, large area coverage total lightning detector. It has a number of unique design features that will enable it have near uniform special resolution over most of its field of view and to operate with minimal impact on performance during solar eclipses. The GLM has no dedicated on-orbit calibration system, thus the ground-based calibration provides the bases for the predicted radiometric performance. A number of problems were encountered during the calibration of Flight Model 1. The issues arouse from GLM design features including its wide field of view, fast lens, the narrow-band interference filters located in both object and collimated space and the fact that the GLM is inherently a event detector yet the calibration procedures required both calibration of images and events. The GLM calibration techniques were based on those developed for the Lightning Imaging Sensor calibration, but there are enough differences between the sensors that the initial GLM calibration suggested that it is significantly more sensitive than its design parameters. The calibration discrepancies have

Constraining Polarized Foregrounds for EoR Experiments. II. Polarization Leakage Simulations in the Avoidance Scheme

Energy Technology Data Exchange (ETDEWEB)

Nunhokee, C. D.; Bernardi, G.; Foster, G.; Grobler, T. L. [Department of Physics and Electronics, Rhodes University, P.O. Box 94, Grahamstown, 6140 (South Africa); Kohn, S. A.; Aguirre, J. E.; Martinot, J. Z. E. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA (United States); Thyagarajan, N. [Arizona State University, School of Earth and Space Exploration, Tempe, AZ 85287 (United States); Dillon, J. S. [Berkeley Center for Cosmological Physics, Berkeley, CA 94720 (United States); Parsons, A. R., E-mail: cnunhokee@gmail.com [Dept. of Astronomy, University of California, Berkeley, CA 94720 (United States)

2017-10-10

A critical challenge in the observation of the redshifted 21 cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21 cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. We construct polarized sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Array to Probe the Epoch of Reionization. We find that the leakage due to a population of polarized point sources is expected to be higher than diffuse Galactic polarization at any k mode for a 30 m reference baseline. For the same reference baseline, a foreground-free window at k > 0.3 h Mpc{sup −1} can be defined in terms of leakage from diffuse Galactic polarization even under the most pessimistic assumptions. If measurements of polarized foreground power spectra or a model of polarized foregrounds are given, our method is able to predict the polarization leakage in actual 21 cm observations, potentially enabling its statistical subtraction from the measured 21 cm power spectrum.

Calibration service of radiation detectors and dosemeters at IPEN/ Sao Paulo

Energy Technology Data Exchange (ETDEWEB)

Potiens, M.P.A.; Caldas, L.V.E. [IPEN, CNEN/SP, Sao Paulo (Brazil)]. e-mail: mppalbu@ipen.br

2006-07-01

The Calibration Laboratory of Instituto de Pesquisas Energeticas e Nucleares, IPEN, has already over 25 years been calibrating instruments used in radiation protection and therapy measurements and belonging to hospitals, industries, clinics and other users located in Sao Paulo and in other parts of Brazil. At the present time, the Calibration Laboratory is part of the Radiation Metrology Center and it acts in the Radiation Protection, Radiation Therapy, Nuclear Medicine and Diagnostic Radiology areas, using special set-ups with gamma and beta radiation sealed sources, alpha and beta radiation plane sources and low and intermediate energies of X radiation. Moreover, it has reference instruments for each calibration area with traceability to the Brazilian National Laboratory for Metrology of Ionizing Radiation (secondary standards) and international laboratories (primary standards). The number of tested instruments is increasing annually (from 170 in 1980 to 1871 in 2005), and for the development of new techniques and radiation detectors the continuous improvement of the existing calibration methods is necessary, as well as the establishment of new calibration services to be offered by the Calibration Laboratory for Brazilian and South American users. The objective of this study is to show the evolution of the calibration service developed at IPEN, describing the applied methods and the calibrated instruments types. The quality system implantation process following the basis of the NBR IEC/ISO 17025 standard is also presented with some tools used in the calibration procedures. (Author)

Calibration service of radiation detectors and dosemeters at IPEN/ Sao Paulo

International Nuclear Information System (INIS)

Potiens, M.P.A.; Caldas, L.V.E.

2006-01-01

The Calibration Laboratory of Instituto de Pesquisas Energeticas e Nucleares, IPEN, has already over 25 years been calibrating instruments used in radiation protection and therapy measurements and belonging to hospitals, industries, clinics and other users located in Sao Paulo and in other parts of Brazil. At the present time, the Calibration Laboratory is part of the Radiation Metrology Center and it acts in the Radiation Protection, Radiation Therapy, Nuclear Medicine and Diagnostic Radiology areas, using special set-ups with gamma and beta radiation sealed sources, alpha and beta radiation plane sources and low and intermediate energies of X radiation. Moreover, it has reference instruments for each calibration area with traceability to the Brazilian National Laboratory for Metrology of Ionizing Radiation (secondary standards) and international laboratories (primary standards). The number of tested instruments is increasing annually (from 170 in 1980 to 1871 in 2005), and for the development of new techniques and radiation detectors the continuous improvement of the existing calibration methods is necessary, as well as the establishment of new calibration services to be offered by the Calibration Laboratory for Brazilian and South American users. The objective of this study is to show the evolution of the calibration service developed at IPEN, describing the applied methods and the calibrated instruments types. The quality system implantation process following the basis of the NBR IEC/ISO 17025 standard is also presented with some tools used in the calibration procedures. (Author)

Review of regulatory requirements relevant to calibration of monitoring instruments in research reactors

Energy Technology Data Exchange (ETDEWEB)

Gomaa, Hassan; Khedr, Ahmed; El-Din Talha, Kamal [Egyptian Nuclear and Radiological Regulatory Authority, Cairo (Egypt). Nuclear Safety Engineering Dept.

2015-05-15

The objective of this work is to demonstrate the regulatory requirements pertaining to calibration of monitoring instruments in research reactors. The regulatory statements concerning this subject in IAEA safety standards and the implementation of such regulations in twelve countries with different levels of nuclear programs are surveyed: Australia, Bulgaria, Canada, Egypt, Finland, Germany, Hungary, Slovenia, South Korea, Spain, United Kingdom of England and United States of America. In addition, the requirements of ISO/IEC17025 and NUPIC (Nuclear Utilities Procurement Issues Committee) are compared. Seven technical and administrate aspects are suggested as the comparison criteria and the explicit expression of the statements, the level of document (i.e.: act, requirement or guide) are the considered resources. The main differences and similarities between the different approaches are identified in order to provide an input for future development of the national regulations.

VIIRS-J1 Polarization Narrative

Science.gov (United States)

Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith; Butler, James; Meister, Gerhard; Thome, Kurtis J.

2015-01-01

The VIS/NIR bands polarization sensitivity of Joint Polar Satellite Sensor 1 (JPSS1) Visible/Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5%, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4%, 4.4%, 3.1%, and 4.3%, respectively with a polarization characterization uncertainty of less than 0.3%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands was mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the instruments two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at Goddard and NIST and the use of NIST's T-SIRCUS for polarization testing and associated analyses and results.

Calibration transfer of a Raman spectroscopic quantification method for the assessment of liquid detergent compositions between two at-line instruments installed at two liquid detergent production plants.

Science.gov (United States)

Brouckaert, D; Uyttersprot, J-S; Broeckx, W; De Beer, T

2017-09-01

Calibration transfer of partial least squares (PLS) quantification models is established between two Raman spectrometers located at two liquid detergent production plants. As full recalibration of existing calibration models is time-consuming, labour-intensive and costly, it is investigated whether the use of mathematical correction methods requiring only a handful of standardization samples can overcome the dissimilarities in spectral response observed between both measurement systems. Univariate and multivariate standardization approaches are investigated, ranging from simple slope/bias correction (SBC), local centring (LC) and single wavelength standardization (SWS) to more complex direct standardization (DS) and piecewise direct standardization (PDS). The results of these five calibration transfer methods are compared reciprocally, as well as with regard to a full recalibration. Four PLS quantification models, each predicting the concentration of one of the four main ingredients in the studied liquid detergent composition, are aimed at transferring. Accuracy profiles are established from the original and transferred quantification models for validation purposes. A reliable representation of the calibration models performance before and after transfer is thus established, based on β-expectation tolerance intervals. For each transferred model, it is investigated whether every future measurement that will be performed in routine will be close enough to the unknown true value of the sample. From this validation, it is concluded that instrument standardization is successful for three out of four investigated calibration models using multivariate (DS and PDS) transfer approaches. The fourth transferred PLS model could not be validated over the investigated concentration range, due to a lack of precision of the slave instrument. Comparing these transfer results to a full recalibration on the slave instrument allows comparison of the predictive power of both Raman

QA experience at the University of Wisconsin accredited dosimetry calibration laboratory

Energy Technology Data Exchange (ETDEWEB)

DeWard, L.A.; Micka, J.A. [Univ. of Wisconsin, Madison, WI (United States)

1993-12-31

The University of Wisconsin Accredited Dosimetry Calibration Laboratory (UW ADCL) employs procedure manuals as part of its Quality Assurance (QA) program. One of these manuals covers the QA procedures and results for all of the UW ADCL measurement equipment. The QA procedures are divided into two main areas: QA for laboratory equipment and QA for external chambers sent for calibration. All internal laboratory equipment is checked and recalibrated on an annual basis, after establishing its consistency on a 6-month basis. QA for external instruments involves checking past calibration history as well as comparing to a range of calibration values for specific instrument models. Generally, the authors find that a chamber will have a variation of less than 0.5 % from previous Co-60 calibration factors, and falls within two standard deviations of previous calibrations. If x-ray calibrations are also performed, the energy response of the chamber is plotted and compared to previous instruments of the same model. These procedures give the authors confidence in the transfer of calibration values from National Institute of Standards and Technology (NIST).

QA experience at the University of Wisconsin accredited dosimetry calibration laboratory

International Nuclear Information System (INIS)

DeWard, L.A.; Micka, J.A.

1993-01-01

The University of Wisconsin Accredited Dosimetry Calibration Laboratory (UW ADCL) employs procedure manuals as part of its Quality Assurance (QA) program. One of these manuals covers the QA procedures and results for all of the UW ADCL measurement equipment. The QA procedures are divided into two main areas: QA for laboratory equipment and QA for external chambers sent for calibration. All internal laboratory equipment is checked and recalibrated on an annual basis, after establishing its consistency on a 6-month basis. QA for external instruments involves checking past calibration history as well as comparing to a range of calibration values for specific instrument models. Generally, the authors find that a chamber will have a variation of less than 0.5 % from previous Co-60 calibration factors, and falls within two standard deviations of previous calibrations. If x-ray calibrations are also performed, the energy response of the chamber is plotted and compared to previous instruments of the same model. These procedures give the authors confidence in the transfer of calibration values from National Institute of Standards and Technology (NIST)

The Moon Mineralogy Mapper (M3) imaging spectrometer for lunar science: Instrument description, calibration, on-orbit measurements, science data calibration and on-orbit validation

Science.gov (United States)

Green, R.O.; Pieters, C.; Mouroulis, P.; Eastwood, M.; Boardman, J.; Glavich, T.; Isaacson, P.; Annadurai, M.; Besse, S.; Barr, D.; Buratti, B.; Cate, D.; Chatterjee, A.; Clark, R.; Cheek, L.; Combe, J.; Dhingra, D.; Essandoh, V.; Geier, S.; Goswami, J.N.; Green, R.; Haemmerle, V.; Head, J.; Hovland, L.; Hyman, S.; Klima, R.; Koch, T.; Kramer, G.; Kumar, A.S.K.; Lee, Kenneth; Lundeen, S.; Malaret, E.; McCord, T.; McLaughlin, S.; Mustard, J.; Nettles, J.; Petro, N.; Plourde, K.; Racho, C.; Rodriquez, J.; Runyon, C.; Sellar, G.; Smith, C.; Sobel, H.; Staid, M.; Sunshine, J.; Taylor, L.; Thaisen, K.; Tompkins, S.; Tseng, H.; Vane, G.; Varanasi, P.; White, M.; Wilson, D.

2011-01-01

The NASA Discovery Moon Mineralogy Mapper imaging spectrometer was selected to pursue a wide range of science objectives requiring measurement of composition at fine spatial scales over the full lunar surface. To pursue these objectives, a broad spectral range imaging spectrometer with high uniformity and high signal-to-noise ratio capable of measuring compositionally diagnostic spectral absorption features from a wide variety of known and possible lunar materials was required. For this purpose the Moon Mineralogy Mapper imaging spectrometer was designed and developed that measures the spectral range from 430 to 3000 nm with 10 nm spectral sampling through a 24 degree field of view with 0.7 milliradian spatial sampling. The instrument has a signal-to-noise ratio of greater than 400 for the specified equatorial reference radiance and greater than 100 for the polar reference radiance. The spectral cross-track uniformity is >90% and spectral instantaneous field-of-view uniformity is >90%. The Moon Mineralogy Mapper was launched on Chandrayaan-1 on the 22nd of October. On the 18th of November 2008 the Moon Mineralogy Mapper was turned on and collected a first light data set within 24 h. During this early checkout period and throughout the mission the spacecraft thermal environment and orbital parameters varied more than expected and placed operational and data quality constraints on the measurements. On the 29th of August 2009, spacecraft communication was lost. Over the course of the flight mission 1542 downlinked data sets were acquired that provide coverage of more than 95% of the lunar surface. An end-to-end science data calibration system was developed and all measurements have been passed through this system and delivered to the Planetary Data System (PDS.NASA.GOV). An extensive effort has been undertaken by the science team to validate the Moon Mineralogy Mapper science measurements in the context of the mission objectives. A focused spectral, radiometric

Recent advance in polar seismology: Global impact of the International Polar Year

Science.gov (United States)

Kanao, Masaki; Zhao, Dapeng; Wiens, Douglas A.; Stutzmann, Éléonore

2015-03-01

The most exciting initiative for the recent polar studies was the International Polar Year (IPY) in 2007-2008. The IPY has witnessed a growing community of seismologists who have made considerable efforts to acquire high-quality data in polar regions. It also provided an excellent opportunity to make significant advances in seismic instrumentation of the polar regions to achieve scientific targets involving global issues. Taking these aspects into account, we organize and publish a special issue in Polar Science on the recent advance in polar seismology and cryoseismology as fruitful achievements of the IPY.

A new Cassegrain calibration lamp unit for the Blanco Telescope

Science.gov (United States)

Points, S. D.; James, D. J.; Tighe, R.; Montané, A.; David, N.; Martínez, M.

2016-08-01

The f/8 RC-Cassegrain Focus of the Blanco Telescope at Cerro Tololo Inter-American Observatory, hosts two new instruments: COSMOS, a multi-object spectrograph in the visible wavelength range (350 - 1030nm), and ARCoIRIS, a NIR cross-dispersed spectrograph featuring 6 spectral orders spanning 0.8 - 2.45μm. Here we describe a calibration lamp unit designed to deliver the required illumination at the telescope focal plane for both instruments. These requirements are: (1) an f/8 beam of light covering a spot of 92mm diameter (or 10 arcmin) for a wavelength range of 0.35μm through 2.5μm and (2) no saturation of flat-field calibrations for the minimal exposure times permitted by each instrument, and (3) few saturated spectral lines when using the wavelength calibration lamps for the instruments. To meet these requirements this unit contains an adjustable quartz halogen lamp for flat-field calibrations, and one hollow cathode lamp and four penray lamps for wavelength calibrations. The wavelength calibration lamps are selected to provide optimal spectral coverage for the instrument mounted and can be used individually or in sets. The device designed is based on an 8-inch diameter integrating sphere, the output of which is optimized to match the f/8 calibration input delivery system which is a refractive system based on fused-silica lenses. We describe the optical design, the opto-mechanical design, the electronic control and give results of the performance of the system.

Fiber-Based Polarization Diversity Detection for Polarization-Sensitive Optical Coherence Tomography

Directory of Open Access Journals (Sweden)

Hamid Pahlevaninezhad

2014-09-01

Full Text Available We present a new fiber-based polarization diversity detection (PDD scheme for polarization sensitive optical coherence tomography (PSOCT. This implementation uses a new custom miniaturized polarization-maintaining fiber coupler with single mode (SM fiber inputs and polarization maintaining (PM fiber outputs. The SM fiber inputs obviate matching the optical lengths of the two orthogonal OCT polarization channels prior to interference while the PM fiber outputs ensure defined orthogonal axes after interference. Advantages of this detection scheme over those with bulk optics PDD include lower cost, easier miniaturization, and more relaxed alignment and handling issues. We incorporate this PDD scheme into a galvanometer-scanned OCT system to demonstrate system calibration and PSOCT imaging of an achromatic quarter-wave plate, fingernail in vivo, and chicken breast, salmon, cow leg, and basa fish muscle samples ex vivo.

Determination of alternative conditions for instruments calibration with beta radiation

International Nuclear Information System (INIS)

Rocha, F.D.G.; Caldas, L.V.E.

1992-01-01

The influence of homogenization filter in the determination of chamber calibration factors and transmission factors of beta radiation in air, for obtaining different alternative conditions for beta-gamma portable monitors calibration was studied, using an extrapolation chamber and the beta secondary system at IPEN-CNEN-Brazil. (C.G.C.)

Calibration and Sequence Development Status for the Sample Analysis at Mars Investigation on the Mars Science Laboratory

Science.gov (United States)

Mahaffy, Paul R.

2012-01-01

The measurement goals of the Sample Analysis at Mars (SAM) instrument suite on the "Curiosity" Rover of the Mars Science Laboratory (MSL) include chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples [1,2]. SAM directly supports the ambitious goals of the MSL mission to provide a quantitative assessment of habitability and preservation in Gale crater by means of a range of chemical and geological measurements [3]. The SAM FM combined calibration and environmental testing took place primarily in 2010 with a limited set of tests implemented after integration into the rover in January 2011. The scope of SAM FM testing was limited both to preserve SAM consumables such as life time of its electromechanical elements and to minimize the level of terrestrial contamination in the SAM instrument. A more comprehensive calibration of a SAM-like suite of instruments will be implemented in 2012 with calibration runs planned for the SAM testbed. The SAM Testbed is nearly identical to the SAM FM and operates in a ambient pressure chamber. The SAM Instrument Suite: SAM's instruments are a Quadrupole Mass Spectrometer (QMS), a 6-column Gas Chromatograph (GC), and a 2-channel Tunable Laser Spectrometer (TLS). Gas Chromatography Mass Spectrometry is designed for identification of even trace organic compounds. The TLS [5] secures the C, H, and O isotopic composition in carbon dioxide, water, and methane. Sieved materials are delivered from the MSL sample acquisition and processing system to one of68 cups of the Sample Manipulation System (SMS). 59 of these cups are fabricated from inert quartz. After sample delivery, a cup is inserted into one of 2 ovens for evolved gas analysis (EGA ambient to >9500C) by the QMS and TLS. A portion of the gas released can be trapped and subsequently analyzed by GCMS. Nine sealed cups contain liquid solvents and chemical derivatization or thermochemolysis agents to extract and transform polar molecules

Suomi-NPP VIIRS Day-Night Band On-Orbit Calibration and Performance

Science.gov (United States)

Chen, Hongda; Xiong, Xiaoxiong; Sun, Chengbo; Chen, Xuexia; Chiang, Kwofu

2017-01-01

The Suomi national polar-orbiting partnership Visible Infrared Imaging Radiometer Suite (VIIRS) instrument has successfully operated since its launch in October 2011. The VIIRS day-night band (DNB) is a panchromatic channel covering wavelengths from 0.5 to 0.9 microns that is capable of observing Earth scenes during both daytime and nighttime at a spatial resolution of 750 m. To cover the large dynamic range, the DNB operates at low-, middle-, and high-gain stages, and it uses an on-board solar diffuser (SD) for its low-gain stage calibration. The SD observations also provide a means to compute the gain ratios of low-to-middle and middle-to-high gain stages. This paper describes the DNB on-orbit calibration methodology used by the VIIRS characterization support team in supporting the NASA Earth science community with consistent VIIRS sensor data records made available by the land science investigator-led processing systems. It provides an assessment and update of the DNB on-orbit performance, including the SD degradation in the DNB spectral range, detector gain and gain ratio trending, and stray-light contamination and its correction. Also presented in this paper are performance validations based on Earth scenes and lunar observations, and comparisons to the calibration methodology used by the operational interface data processing segment.

Inter-instrument calibration using magnetic field data from Flux Gate Magnetometer (FGM) and Electron Drift Instrument (EDI) onboard Cluster

Science.gov (United States)

Nakamura, R.; Plaschke, F.; Teubenbacher, R.; Giner, L.; Baumjohann, W.; Magnes, W.; Steller, M.; Torbert, R. B.; Vaith, H.; Chutter, M.; Fornaçon, K.-H.; Glassmeier, K.-H.; Carr, C.

2013-07-01

We compare the magnetic field data obtained from the Flux-Gate Magnetometer (FGM) and the magnetic field data deduced from the gyration time of electrons measured by the Electron Drift Instrument (EDI) onboard Cluster to determine the spin axis offset of the FGM measurements. Data are used from orbits with their apogees in the magnetotail, when the magnetic field magnitude was between about 20 nT and 500 nT. Offset determination with the EDI-FGM comparison method is of particular interest for these orbits, because no data from solar wind are available in such orbits to apply the usual calibration methods using the Alfvén waves. In this paper, we examine the effects of the different measurement conditions, such as direction of the magnetic field relative to the spin plane and field magnitude in determining the FGM spin-axis offset, and also take into account the time-of-flight offset of the EDI measurements. It is shown that the method works best when the magnetic field magnitude is less than about 128 nT and when the magnetic field is aligned near the spin-axis direction. A remaining spin-axis offset of about 0.4 ~ 0.6 nT was observed between July and October 2003. Using multi-point multi-instrument measurements by Cluster we further demonstrate the importance of the accurate determination of the spin-axis offset when estimating the magnetic field gradient.

Some problems in calibrating surface contamination meters

International Nuclear Information System (INIS)

Chen Zigen; LI Xingyuan; Shuai Xiaoping.

1984-01-01

It is necessary that instruments are calibrated accurately in order to obtain reliable survey data of surface contamination. Some problems in calibrating surface contamination meters are expounded in this paper. Measurement comparison for beta surface contamination meters is organized within limited scope, thus survey quality is understood, questions are discovered, significance of calibration is expounded further. (Author)

Planck 2015 results: V. LFI calibration

DEFF Research Database (Denmark)

Ade, P. A R; Aghanim, N.; Ashdown, M.

2016-01-01

We present a description of the pipeline used to calibrate the Planck Low Frequency Instrument (LFI) timelines into thermodynamic temperatures for the Planck 2015 data release, covering four years of uninterrupted operations. As in the 2013 data release, our calibrator is provided by the spin-syn...

U.S. Department of Energy Office of Legacy Management Calibration Facilities - 12103

Energy Technology Data Exchange (ETDEWEB)

Barr, Deborah [U.S. Department of Energy Office of Legacy Management, Grand Junction, Colorado (United States); Traub, David; Widdop, Michael [S.M. Stoller Corporation, Grand Junction, Colorado (United States)

2012-07-01

This paper describes radiometric calibration facilities located in Grand Junction, Colorado, and at three secondary calibration sites. These facilities are available to the public for the calibration of radiometric field instrumentation for in-situ measurements of radium (uranium), thorium, and potassium. Both borehole and hand-held instruments may be calibrated at the facilities. Aircraft or vehicle mounted systems for large area surveys may be calibrated at the Grand Junction Regional Airport facility. These calibration models are recognized internationally as stable, well-characterized radiation sources for calibration. Calibration models built in other countries are referenced to the DOE models, which are also widely used as a standard for calibration within the U.S. Calibration models are used to calibrate radiation detectors used in uranium exploration, remediation, and homeland security. (authors)

Results of the first air ion spectrometer calibration and intercomparison workshop

Directory of Open Access Journals (Sweden)

E. Asmi

2009-01-01

Full Text Available The Air Ion Spectrometer (AIS measures mobility and size distributions of atmospheric ions. The Neutral cluster and Air Ion Spectrometer (NAIS can additionally measure neutral particles. The number of the (NAIS instruments in the world is only 11. Nevertheless, they are already widely used in atmospheric ion studies, particularly related to the initial steps of new particle formation. There is no standard method applicable for calibrating the ion spectrometers in the sub-3 nm ion range. However, recent development of high resolution DMAs has enabled the size separation of small ions with good mobility resolution. For the first time, the ion spectrometers were intercompared and calibrated in a workshop, held in January–February 2008 in Helsinki, Finland. The overall goal was to experimentally determine the (NAIS transfer functions. Monomobile mobility standards, 241-Am charger ions and silver particles were generated and used as calibration aerosols. High resolution DMAs were used to size-separate the smaller (1–10 nm ions, while at bigger diameters (4–40 nm the size was selected with a HAUKE-type DMA. Negative ion mobilities were detected by (NAISs with slightly better accuracy than positive, nonetheless, both were somewhat overestimated. A linear fit of slope of one to the whole dataset of mobilities suggested that (NAISs measured the negative mobilities 1.36±0.16 times larger compared with the reference instruments. Similarly, positive mobilities were measured 1.39±0.15 times larger compared with the reference instruments. The completely monomobile mobility standards were measured with the best accuracy. The (NAIS concentrations were compared with an aerosol electrometer (AE and a condensation particle counter (CPC. At sizes below 1.5 nm (positive and 3 nm (negative the ion spectrometers detected higher concentrations while at bigger sizes they showed similar concentrations as the reference instruments. The total particle

Applying neural networks to optimize instrumentation performance

Energy Technology Data Exchange (ETDEWEB)

Start, S.E.; Peters, G.G.

1995-06-01

Well calibrated instrumentation is essential in providing meaningful information about the status of a plant. Signals from plant instrumentation frequently have inherent non-linearities, may be affected by environmental conditions and can therefore cause calibration difficulties for the people who maintain them. Two neural network approaches are described in this paper for improving the accuracy of a non-linear, temperature sensitive level probe ised in Expermental Breeder Reactor II (EBR-II) that was difficult to calibrate.

Applying neural networks to optimize instrumentation performance

International Nuclear Information System (INIS)

Start, S.E.; Peters, G.G.

1995-01-01

Well calibrated instrumentation is essential in providing meaningful information about the status of a plant. Signals from plant instrumentation frequently have inherent non-linearities, may be affected by environmental conditions and can therefore cause calibration difficulties for the people who maintain them. Two neural network approaches are described in this paper for improving the accuracy of a non-linear, temperature sensitive level probe ised in Expermental Breeder Reactor II (EBR-II) that was difficult to calibrate

Beyond Californium-A Neutron Generator Alternative for Dosimetry and Instrument Calibration in the U.S.

Science.gov (United States)

Piper, Roman K; Mozhayev, Andrey V; Murphy, Mark K; Thompson, Alan K

2017-09-01

Evaluations of neutron survey instruments, area monitors, and personal dosimeters rely on reference neutron radiations, which have evolved from the heavy reliance on (α,n) sources to a shared reliance on (α,n) and the spontaneous fission neutrons of californium-252 (Cf). Capable of producing high dose equivalent rates from an almost point source geometry, the characteristics of Cf are generally more favorable when compared to the use of (α,n) and (γ,n) sources or reactor-produced reference neutron radiations. Californium-252 is typically used in two standardized configurations: unmoderated, to yield a fission energy spectrum; or with the capsule placed within a heavy-water moderating sphere to produce a softened spectrum that is generally considered more appropriate for evaluating devices used in nuclear power plant work environments. The U.S. Department of Energy Cf Loan/Lease Program, a longtime origin of affordable Cf sources for research, testing and calibration, was terminated in 2009. Since then, high-activity sources have become increasingly cost-prohibitive for laboratories that formerly benefited from that program. Neutron generators, based on the D-T and D-D fusion reactions, have become economically competitive with Cf and are recognized internationally as important calibration and test standards. Researchers from the National Institute of Standards and Technology and the Pacific Northwest National Laboratory are jointly considering the practicality and technical challenges of implementing neutron generators as calibration standards in the U.S. This article reviews the characteristics of isotope-based neutron sources, possible isotope alternatives to Cf, and the rationale behind the increasing favor of electronically generated neutron options. The evaluation of a D-T system at PNNL has revealed characteristics that must be considered in adapting generators to the task of calibration and testing where accurate determination of a dosimetric quantity is

Calibration Uncertainty in Ocean Color Satellite Sensors and Trends in Long-term Environmental Records

Science.gov (United States)

Turpie, Kevin R.; Eplee, Robert E., Jr.; Franz, Bryan A.; Del Castillo, Carlos

2014-01-01

Launched in late 2011, the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (NPP) spacecraft is being evaluated by NASA to determine whether this sensor can continue the ocean color data record established through the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) and the MODerate resolution Imaging Spectroradiometer (MODIS). To this end, Goddard Space Flight Center generated evaluation ocean color data products using calibration techniques and algorithms established by NASA during the SeaWiFS and MODIS missions. The calibration trending was subjected to some initial sensitivity and uncertainty analyses. Here we present an introductory assessment of how the NASA-produced time series of ocean color is influenced by uncertainty in trending instrument response over time. The results help quantify the uncertainty in measuring regional and global biospheric trends in the ocean using satellite remote sensing, which better define the roles of such records in climate research.

Gearbox Reliability Collaborative High-Speed Shaft Calibration

Energy Technology Data Exchange (ETDEWEB)

Keller, J.; McNiff, B.

2014-09-01

Instrumentation has been added to the high-speed shaft, pinion, and tapered roller bearing pair of the Gearbox Reliability Collaborative gearbox to measure loads and temperatures. The new shaft bending moment and torque instrumentation was calibrated and the purpose of this document is to describe this calibration process and results, such that the raw shaft bending and torque signals can be converted to the proper engineering units and coordinate system reference for comparison to design loads and simulation model predictions.

Observing the Cosmic Microwave Background Polarization with Variable-delay Polarization Modulators for the Cosmology Large Angular Scale Surveyor

Science.gov (United States)

Harrington, Kathleen; CLASS Collaboration

2018-01-01

The search for inflationary primordial gravitational waves and the optical depth to reionization, both through their imprint on the large angular scale correlations in the polarization of the cosmic microwave background (CMB), has created the need for high sensitivity measurements of polarization across large fractions of the sky at millimeter wavelengths. These measurements are subjected to instrumental and atmospheric 1/f noise, which has motivated the development of polarization modulators to facilitate the rejection of these large systematic effects.Variable-delay polarization modulators (VPMs) are used in the Cosmology Large Angular Scale Surveyor (CLASS) telescopes as the first element in the optical chain to rapidly modulate the incoming polarization. VPMs consist of a linearly polarizing wire grid in front of a moveable flat mirror; varying the distance between the grid and the mirror produces a changing phase shift between polarization states parallel and perpendicular to the grid which modulates Stokes U (linear polarization at 45°) and Stokes V (circular polarization). The reflective and scalable nature of the VPM enables its placement as the first optical element in a reflecting telescope. This simultaneously allows a lock-in style polarization measurement and the separation of sky polarization from any instrumental polarization farther along in the optical chain.The Q-Band CLASS VPM was the first VPM to begin observing the CMB full time in 2016. I will be presenting its design and characterization as well as demonstrating how modulating polarization significantly rejects atmospheric and instrumental long time scale noise.

Calibration of measurement instruments in industrial irradiation environment

International Nuclear Information System (INIS)

Cadiou, A.

2009-01-01

After having recalled the activities of the AREVA NC site in La Hague and its organization, the author describes the missions of the Calibration Laboratory within this establishment, its methods, its metrological means, and outlines the traceability of results

Polar-interferometry: what can be learnt from the IOTA/IONIC experiment

Science.gov (United States)

Le Bouquin, Jean-Baptiste; Rousselet-Perraut, Karine; Berger, Jean-Philippe; Herwats, Emilie; Benisty, Myriam; Absil, Olivier; Defrere, Denis; Monnier, John; Traub, Wesley

2008-07-01

We report the first near-IR polar-interferometric observations, performed at the IOTA array using its integrated optics combiner IONIC. Fringes have been obtained on calibration stars and resolved late-type giants. Optical modeling of the array and dedicated laboratory measures allowed us to confirm the good accuracy obtained on the calibrated polarized visibilities and closure phases. However, no evidences for polarimetric features at high angular resolution have been detected. The simulations and the results presented here open several perspectives for polar-interferometry, especially in the context of fibered, single-mode combiners.

Comparison of infusion pumps calibration methods

Science.gov (United States)

Batista, Elsa; Godinho, Isabel; do Céu Ferreira, Maria; Furtado, Andreia; Lucas, Peter; Silva, Claudia

2017-12-01

Nowadays, several types of infusion pump are commonly used for drug delivery, such as syringe pumps and peristaltic pumps. These instruments present different measuring features and capacities according to their use and therapeutic application. In order to ensure the metrological traceability of these flow and volume measuring equipment, it is necessary to use suitable calibration methods and standards. Two different calibration methods can be used to determine the flow error of infusion pumps. One is the gravimetric method, considered as a primary method, commonly used by National Metrology Institutes. The other calibration method, a secondary method, relies on an infusion device analyser (IDA) and is typically used by hospital maintenance offices. The suitability of the IDA calibration method was assessed by testing several infusion instruments at different flow rates using the gravimetric method. In addition, a measurement comparison between Portuguese Accredited Laboratories and hospital maintenance offices was performed under the coordination of the Portuguese Institute for Quality, the National Metrology Institute. The obtained results were directly related to the used calibration method and are presented in this paper. This work has been developed in the framework of the EURAMET projects EMRP MeDD and EMPIR 15SIP03.

Continuous Calibration Improvement in Solar Reflective Bands: Landsat 5 Through Landsat 8

Science.gov (United States)

Mishra, Nischal; Helder, Dennis; Barsi, Julia; Markham, Brian

2016-01-01

Launched in February 2013, the Operational Land Imager (OLI) on-board Landsat 8 continues to perform exceedingly well and provides high science quality data globally. Several design enhancements have been made in the OLI instrument relative to prior Landsat instruments: pushbroom imaging which provides substantially improved Signal-to-Noise Ratio (SNR), spectral bandpasses refinement to avoid atmospheric absorption features, 12 bit data resolution to provide a larger dynamic range that limits the saturation level, a set of well-designed onboard calibrators to monitor the stability of the sensor. Some of these changes such as refinements in spectral bandpasses compared to earlier Landsats and well-designed on-board calibrator have a direct impact on the improved radiometric calibration performance of the instrument from both the stability of the response and the ability to track the changes. The on-board calibrator lamps and diffusers indicate that the instrument drift is generally less than 0.1% per year across the bands. The refined bandpasses of the OLI indicate that temporal uncertainty of better than 0.5% is possible when the instrument is trended over vicarious targets such as Pseudo Invariant Calibration Sites (PICS), a level of precision that was never achieved with the earlier Landsat instruments. The stability measurements indicated by on-board calibrators and PICS agree much better compared to the earlier Landsats, which is very encouraging and bodes well for the future Landsat missions too.

Laboratory for Calibration of Gamma Radiation Measurement Instruments (LabCal) of Institute of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN) from Brazilian Army Technology Center (CTEx); Laboratorio de Calibracao de Instrumentode Medicao de Radiacao Gama (LabCal) do IDQBRN do CTEx

Energy Technology Data Exchange (ETDEWEB)

Amorim, Aneuri de; Balthar, Mario Cesar V.; Santos, Avelino; Vilela, Paulo Ricardo T. de; Oliveira, Luciano Santa Rita; Penha, Paulo Eduardo C. de Oliveira; Gonzaga, Roberto Neves; Andrade, Edson Ramos de; Oliveira, Celio Jorge Vasques de; Fagundes, Luiz Cesar S., E-mail: aneurideamorim@gmail.com [Centro Tecnologico do Exercito (DQBRN/CTEx), Rio de Janeiro, RJ (Brazil). Instituto de Defesa Quimica, Biologica, Radiologica e Nuclear

2016-07-01

This paper describes the calibration laboratory deployment steps (LABCAL) gamma ionizing radiation measuring instruments in the Army Technology Center, CTEx. Initially the calibration of radiation monitors will be held in the dosimetric quantity air kerma and operational quantity ambient dose equivalent H*(d). The LABCAL / CTEx has not yet authorized by CASEC / CNEN. This laboratory aims to calibrate the ionizing radiation instruments used by the Brazilian Army. (author)

40 CFR 86.116-94 - Calibrations, frequency and overview.

Science.gov (United States)

2010-07-01

... positive displacement pump or Critical Flow Venturi shall be calibrated following initial installation... an organic gas retention and calibration on the evaporative emissions enclosure (see § 86.117-90(c)). (4) Calibrate the gas meters or flow instrumentation used for providing total flow measurement for...

Rectifying calibration error of Goldmann applanation tonometer is easy!

Directory of Open Access Journals (Sweden)

Nikhil S Choudhari

2014-01-01

Full Text Available Purpose: Goldmann applanation tonometer (GAT is the current Gold standard tonometer. However, its calibration error is common and can go unnoticed in clinics. Its company repair has limitations. The purpose of this report is to describe a self-taught technique of rectifying calibration error of GAT. Materials and Methods: Twenty-nine slit-lamp-mounted Haag-Streit Goldmann tonometers (Model AT 900 C/M; Haag-Streit, Switzerland were included in this cross-sectional interventional pilot study. The technique of rectification of calibration error of the tonometer involved cleaning and lubrication of the instrument followed by alignment of weights when lubrication alone didn′t suffice. We followed the South East Asia Glaucoma Interest Group′s definition of calibration error tolerance (acceptable GAT calibration error within ±2, ±3 and ±4 mm Hg at the 0, 20 and 60-mm Hg testing levels, respectively. Results: Twelve out of 29 (41.3% GATs were out of calibration. The range of positive and negative calibration error at the clinically most important 20-mm Hg testing level was 0.5 to 20 mm Hg and -0.5 to -18 mm Hg, respectively. Cleaning and lubrication alone sufficed to rectify calibration error of 11 (91.6% faulty instruments. Only one (8.3% faulty GAT required alignment of the counter-weight. Conclusions: Rectification of calibration error of GAT is possible in-house. Cleaning and lubrication of GAT can be carried out even by eye care professionals and may suffice to rectify calibration error in the majority of faulty instruments. Such an exercise may drastically reduce the downtime of the Gold standard tonometer.

Planck 2013 results. V. LFI calibration

DEFF Research Database (Denmark)

Planck Collaboration,; Aghanim, N.; Armitage-Caplan, C.

2014-01-01

We discuss the methods employed to photometrically calibrate the data acquired by the Low Frequency Instrument on Planck. Our calibration is based on the Solar Dipole, caused by motion of the Solar System with respect to the CMB rest frame, which provides a signal of a few mK with the same spectr...

Ibis ground calibration

International Nuclear Information System (INIS)

Bird, A.J.; Barlow, E.J.; Tikkanen, T.; Bazzano, A.; Del Santo, M.; Ubertini, P.; Blondel, C.; Laurent, P.; Lebrun, F.; Di Cocco, G.; Malaguti, E.; Gabriele, M.; La Rosa, G.; Segreto, A.; Quadrini, E.; Volkmer, R.

2003-01-01

We present an overview of results obtained from IBIS ground calibrations. The spectral and spatial characteristics of the detector planes and surrounding passive materials have been determined through a series of calibration campaigns. Measurements of pixel gain, energy resolution, detection uniformity, efficiency and imaging capability are presented. The key results obtained from the ground calibration have been: - optimization of the instrument tunable parameters, - determination of energy linearity for all detection modes, - determination of energy resolution as a function of energy through the range 20 keV - 3 MeV, - demonstration of imaging capability in each mode, - measurement of intrinsic detector non-uniformity and understanding of the effects of passive materials surrounding the detector plane, and - discovery (and closure) of various leakage paths through the passive shielding system

Calibration of an electronic nose for poultry farm

Science.gov (United States)

Abdullah, A. H.; Shukor, S. A.; Kamis, M. S.; Shakaff, A. Y. M.; Zakaria, A.; Rahim, N. A.; Mamduh, S. M.; Kamarudin, K.; Saad, F. S. A.; Masnan, M. J.; Mustafa, H.

2017-03-01

Malodour from the poultry farms could cause air pollution and therefore potentially dangerous to humans' and animals' health. This issue also poses sustainability risk to the poultry industries due to objections from local community. The aim of this paper is to develop and calibrate a cost effective and efficient electronic nose for poultry farm air monitoring. The instrument main components include sensor chamber, array of specific sensors, microcontroller, signal conditioning circuits and wireless sensor networks. The instrument was calibrated to allow classification of different concentrations of main volatile compounds in the poultry farm malodour. The outcome of the process will also confirm the device's reliability prior to being used for poultry farm malodour assessment. The Multivariate Analysis (HCA and KNN) and Artificial Neural Network (ANN) pattern recognition technique was used to process the acquired data. The results show that the instrument is able to calibrate the samples using ANN classification model with high accuracy. The finding verifies the instrument's performance to be used as an effective poultry farm malodour monitoring.

Calibration of the Fermilab E-704 polarized target

International Nuclear Information System (INIS)

Hill, D.A.

1992-01-01

This report lists the final, best estimate of the target polarization P T as a function of time for all of the periods during which scattering data were (or may have been) collected. The information under ''RUN'' refers to Δσ L -runs. The notation ''sfs'' stands for ''start of frozen spin,'' ''efs'' for ''end of frozen spin,'' ''→ la'' for ''go to large-aperture'' target magnet position, and ''nla'' for ''not large-aperture'' position, i.e., the target magnet is in ''polarizing'' position. Where the ''NOTE'' column is blank it means that all standard frozen-spin conditions were in effect: the target temperature was reduced and the magnet was in large-aperture position. The timing marks were developed on the basis of three criteria: (1) the availability of direct NMR data, (2) the inclusion of major Target and Run boundaries, and (3) the arbitrary inclusion of enough ''minor'' Run boundaries to shorten large timing gaps. The sign of the P T -values is given in the NMR convention: (+) corresponds to predominant occupation of the Zeeman ground state (the ''thermal'' NMR-signals are considered positive). Since the target magnet field pointed upstream, (+) corresponds to target spin antiparallel to the beam momentum. The estimated uncertainty on P T is ±6.5% (2σ), and the estimated uncertainty on the ratio of values for the two signs of polarization, P T (+)/PT(-), is ±4.3% (2σ)

Time-of-flight and vector polarization analysis for diffuse neutron scattering

International Nuclear Information System (INIS)

Schweika, W.

2003-01-01

The potential of pulsed neutron sources for diffuse scattering including time-of-flight (TOF) and polarization analysis is discussed in comparison to the capabilities of the present instrument diffuse neutron scattering at the research center Juelich. We present first results of a new method for full polarization analysis using precessing neutron polarization. A proposal is made for a new type of instrument at pulsed sources, which allows for vector polarization analysis in TOF instruments with multi-detectors

Primordial Inflation Polarization Explorer: Status and Plans

Science.gov (United States)

Kogut, Alan

2009-01-01

The Primordial Inflation Polarization Explorer is a balloon-borne instrument to measure the polarization of the cosmic microwave background in order to detect the characteristic signature of gravity waves created during an inflationary epoch in the early universe. PIPER combines cold /I.G K\\ optics, 5120 bolometric detectors, and rapid polarization modulation using VPM grids to achieve both high sensitivity and excellent control of systematic errors. I will discuss the current status and plans for the PIPER instrument.

Using tri-axial accelerometers to identify wild polar bear behaviors

Science.gov (United States)

Pagano, Anthony M.; Rode, Karyn D.; Cutting, A.; Owen, M.A.; Jensen, S.; Ware, J.V.; Robbins, C.T.; Durner, George M.; Atwood, Todd C.; Obbard, M.E.; Middel, K.R.; Thiemann, G.W.; Williams, T.M.

2017-01-01

Tri-axial accelerometers have been used to remotely identify the behaviors of a wide range of taxa. Assigning behaviors to accelerometer data often involves the use of captive animals or surrogate species, as their accelerometer signatures are generally assumed to be similar to those of their wild counterparts. However, this has rarely been tested. Validated accelerometer data are needed for polar bears Ursus maritimus to understand how habitat conditions may influence behavior and energy demands. We used accelerometer and water conductivity data to remotely distinguish 10 polar bear behaviors. We calibrated accelerometer and conductivity data collected from collars with behaviors observed from video-recorded captive polar bears and brown bears U. arctos, and with video from camera collars deployed on free-ranging polar bears on sea ice and on land. We used random forest models to predict behaviors and found strong ability to discriminate the most common wild polar bear behaviors using a combination of accelerometer and conductivity sensor data from captive or wild polar bears. In contrast, models using data from captive brown bears failed to reliably distinguish most active behaviors in wild polar bears. Our ability to discriminate behavior was greatest when species- and habitat-specific data from wild individuals were used to train models. Data from captive individuals may be suitable for calibrating accelerometers, but may provide reduced ability to discriminate some behaviors. The accelerometer calibrations developed here provide a method to quantify polar bear behaviors to evaluate the impacts of declines in Arctic sea ice.

Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite Polarization Sensitivity Analysis

Science.gov (United States)

Sun, Junqiang; Xiong, Xiaoxiong; Waluschka, Eugene; Wang, Menghua

2016-01-01

The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of five instruments onboard the Suomi National Polar-Orbiting Partnership (SNPP) satellite that launched from Vandenberg Air Force Base, California, on October 28, 2011. It is a whiskbroom radiometer that provides +/-56.28deg scans of the Earth view. It has 22 bands, among which 14 are reflective solar bands (RSBs). The RSBs cover a wavelength range from 410 to 2250 nm. The RSBs of a remote sensor are usually sensitive to the polarization of incident light. For VIIRS, it is specified that the polarization factor should be smaller than 3% for 410 and 862 nm bands and 2.5% for other RSBs for the scan angle within +/-45deg. Several polarization sensitivity tests were performed prelaunch for SNPP VIIRS. The first few tests either had large uncertainty or were less reliable, while the last one was believed to provide the more accurate information about the polarization property of the instrument. In this paper, the measured data in the last polarization sensitivity test are analyzed, and the polarization factors and phase angles are derived from the measurements for all the RSBs. The derived polarization factors and phase angles are band, detector, and scan angle dependent. For near-infrared bands, they also depend on the half-angle mirror side. Nevertheless, the derived polarization factors are all within the specification, although the strong detector dependence of the polarization parameters was not expected. Compared to the Moderate Resolution Imaging Spectroradiometer on both Aqua and Terra satellites, the polarization effect on VIIRS RSB is much smaller.

Application of Allan Deviation to Assessing Uncertainties of Continuous-measurement Instruments, and Optimizing Calibration Schemes

Science.gov (United States)

Jacobson, Gloria; Rella, Chris; Farinas, Alejandro

2014-05-01

Technological advancement of instrumentation in atmospheric and other geoscience disciplines over the past decade has lead to a shift from discrete sample analysis to continuous, in-situ monitoring. Standard error analysis used for discrete measurements is not sufficient to assess and compare the error contribution of noise and drift from continuous-measurement instruments, and a different statistical analysis approach should be applied. The Allan standard deviation analysis technique developed for atomic clock stability assessment by David W. Allan [1] can be effectively and gainfully applied to continuous measurement instruments. As an example, P. Werle et al has applied these techniques to look at signal averaging for atmospheric monitoring by Tunable Diode-Laser Absorption Spectroscopy (TDLAS) [2]. This presentation will build on, and translate prior foundational publications to provide contextual definitions and guidelines for the practical application of this analysis technique to continuous scientific measurements. The specific example of a Picarro G2401 Cavity Ringdown Spectroscopy (CRDS) analyzer used for continuous, atmospheric monitoring of CO2, CH4 and CO will be used to define the basics features the Allan deviation, assess factors affecting the analysis, and explore the time-series to Allan deviation plot translation for different types of instrument noise (white noise, linear drift, and interpolated data). In addition, the useful application of using an Allan deviation to optimize and predict the performance of different calibration schemes will be presented. Even though this presentation will use the specific example of the Picarro G2401 CRDS Analyzer for atmospheric monitoring, the objective is to present the information such that it can be successfully applied to other instrument sets and disciplines. [1] D.W. Allan, "Statistics of Atomic Frequency Standards," Proc, IEEE, vol. 54, pp 221-230, Feb 1966 [2] P. Werle, R. Miicke, F. Slemr, "The Limits

Calibration of an electron volt neutron spectrometer

International Nuclear Information System (INIS)

Mayers, J.; Adams, M.A.

2011-01-01

The procedure for calibrating the VESUVIO eV neutron spectrometer at the ISIS neutron source is described. VESUVIO is used primarily to measure the momentum distribution n(p) of atoms, by inelastic scattering of very high energy (5-150 eV) neutrons. The results of the calibrations show that measurements of n(p) in atoms with masses lower than 16 amu can be measured with a resolution width ∼25% of the intrinsic peak widths in the current instrument configuration. Some suggestions as to how the instrument resolution could be significantly improved are made.

Polarization at LEP: Status and prospects

International Nuclear Information System (INIS)

Koutchouk, J.P.

1993-01-01

The first evidence of a measurable signal of transverse polarization was observed at the end of 1990. In 1991, polarized beams were repeatedly obtained with average and peak polarization levels of 10 and 19% and used to calibrate the beam energy by resonant depolarization. Simulation studies show that the polarization level can be increased above the 50% by harmonic spin matching. This is sufficient to open the possibility of doing physics with longitudinally polarized beams. A spin rotator has been designed for LEP. The feasibility study of operating LEP in this mode concludes at the possibility of providing polarized beams at a good performance level, if the high photon background can be reduced to a tolerable level. (author). 10 refs, 3 figs, 5 tabs

In-flight calibration and verification of the Planck-LFI instrument

OpenAIRE

Gregorio, Anna; Cuttaia, Francesco; Mennella, Aniello; Bersanelli, Marco; Maris, Michele; Meinhold, Peter; Sandri, Maura; Terenzi, Luca; Tomasi, Maurizio; Villa, Fabrizio; Frailis, Marco; Morgante, Gianluca; Pearson, Dave; Zacchei, Andrea; Battaglia, Paola

2013-01-01

In this paper we discuss the Planck-LFI in-flight calibration campaign. After a brief overview of the ground test campaigns, we describe in detail the calibration and performance verification (CPV) phase, carried out in space during and just after the cool-down of LFI. We discuss in detail the functionality verification, the tuning of the front-end and warm electronics, the preliminary performance assessment and the thermal susceptibility tests. The logic, sequence, goals and results of the i...

Investigation on calibration parameter of mammography calibration facilities at MINT

International Nuclear Information System (INIS)

Asmaliza Hashim; Wan Hazlinda Ismail; Md Saion Salikin; Muhammad Jamal Md Isa; Azuhar Ripin; Norriza Mohd Isa

2004-01-01

A mammography calibration facility has been established in the Medical Physics Laboratory, Malaysian Institute for Nuclear Technology Research (MINT). The calibration facility is established at the national level mainly to provide calibration services for radiation measuring test instruments or test tools used in quality assurance programme in mammography, which is being implemented in Malaysia. One of the accepted parameters that determine the quality of a radiation beam is the homogeneity coefficient. It is determined from the values of the 1 st and 2 nd Half Value Layer (HVL). In this paper, the consistency of the mammography machine beam qualities that is available in MINT, is investigated and presented. For calibration purposes, five radiation qualities namely 23, 25, 28, 30 and 35 kV, selectable from the control panel of the X-ray machine is used. Important parameters that are set for this calibration facility are exposure time, tube current, focal spot to detector distance (FDD) and beam size at specific distance. The values of homogeneity coefficient of this laboratory for the past few years tip to now be presented in this paper. Backscatter radiations are also considered in this investigation. (Author)

Polarized light and optical measurement

CERN Document Server

Clarke, D N; Ter Haar, D

2013-01-01

Polarized Light and Optical Measurement is a five-chapter book that begins with a self-consistent conceptual picture of the phenomenon of polarization. Chapter 2 describes a number of interactions of light and matter used in devising optical elements in polarization studies. Specific optical elements are given in Chapter 3. The last two chapters explore the measurement of the state of polarization and the various roles played in optical instrumentation by polarization and polarization-sensitive elements. This book will provide useful information in this field of interest for research workers,

Absolute calibration of SARAL/AltiKa in Kavaratti during its initial calibration-validation phase

Digital Repository Service at National Institute of Oceanography (India)

Babu, K.N.; Shukla, A.K.; Suchandra, A.B.; ArunKumar, S.V.V.; Bonnefond, P.; Testut, L.; Mehra, P.; Laurain, O.

globally distributed region will offer assessment of the altimetry system, and allow us to check in specific conditions leading to different estimation of absolute bias of the instrument (Shum et al. 2003). In collaboration with National Institute... of Oceanography (NIO), Goa, Space Applica- tions Centre–Indian Space Research Organisation (SAC-ISRO) established a calibration- verification site in Kavaratti. This site offers a number of advantages as a calibration site for altimeters. Having very small land...

The calibration procedure of the radiation monitoring system installed in radiation controlled area of KOMAC

Energy Technology Data Exchange (ETDEWEB)

Park, Sung-Kyun; Min, Yi-Sub; Park, Jeong-Min; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

2016-10-15

The spaces, where these accelerators are installed, are defined as the radiation controlled area and the levels of the radiation in this area are monitored by the radiation monitoring system (RMS) to protect radiation workers and experiment users from the hazards of the ionizing radiation and the surface and air contamination tests are carried out periodically by the radiation secure team. The most of RMS instruments are installed in the accelerator building, where the 100-MeV proton linear accelerator is installed. All detectors of RMS should be calibrated every year to prove the reliability of RMS and almost all instruments for RMS was calibrated during this summer maintenance period of KOMAC this year. Almost all RMS instruments installed in KOMAC is calibrated between 2016-07-13 and 2016-08-24. As the calibration result, if the current reading value are within the 5% of the reference dose rate value, this RMS instrument can be used one more year. Otherwise, the detector of that RMS instrument should be repaired or replaced. The self-calibration certificate for each RMS instrument will be published only for the instrument to satisfy the condition.

Design and implementation of a wireless instrument adapter

DEFF Research Database (Denmark)

Laino, Kaori V.; Saathoff, Thore; Savarimuthu, Thiusius R.

2018-01-01

The evaluation of new methods for control and manipulation in minimally invasive robotic surgery requires a realistic setup. To decouple the evaluation of methods from overall clinical systems, we propose an instrument adapter for the S line EndoWrist\\c{opyright} instruments of the da Vinci...... surgical system. The adapter is small and lightweight and can be mounted to any robot to mimic motion. We describe its design and implementation, as well as a setup to calibrate instruments to study precise motion control. Our results indicate that each instrument requires individual calibration...

Procedure for calibrating the Technicon Colorimeter I.

Science.gov (United States)

Black, J C; Furman, W B

1975-05-01

We describe a rapid method for calibrating the Technicon AutoAnalyzer colorimeter I. Test solutions of bromphenol blue are recommended for the calibration, in preference to solutions of potassium dichromate, based on considerations of the instrument's working range and of the stray light characteristics of the associated filters.

Tritium monitor calibration at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Bjork, C.J.; Aikin, D.J.; Houlton, T.W.

1997-08-01

Tritium in air is monitored at Los Alamos National Laboratory (LANL) with air breathing instruments based on ionization chambers. Stack emissions are continuously monitored from sample tubes which each connect to a Tritium bubble which differentially collects HTO and HT. A set of glass vials of glycol capture the HTO. The HT is oxidized with a palladium catalyst and the resultant HTO is captured in a second set of vials of glycol. The glycol is counted with a liquid scintillation counter. All calibrations are performed with tritium containing gas. The Radiation Instrumentation and Calibration (RIC) Team has constructed and maintains two closed loop gas handling systems based on femto TECH model U24 tritium ion chamber monitors: a fixed system housed in a fume hood and a portable system mounted on two two wheeled hand trucks. The U24 monitors are calibrated against tritium in nitrogen gas standards. They are used as standard transfer instruments to calibrate other ion chamber monitors with tritium in nitrogen, diluted with air. The gas handling systems include a circulation pump which permits a closed circulation loop to be established among the U24 monitor and typically two to four other monitors of a given model during calibration. Fixed and portable monitors can be calibrated. The stack bubblers are calibrated in the field by: blending a known concentration of tritium in air within the known volume of the two portable carts, coupled into a common loop; releasing that gas mixture into a ventilation intake to the stack; collecting oxidized tritium in the bubbler; counting the glycol; and using the stack and bubbler flow rates, computing the bubbler's efficiency. Gas calibration has become a convenient and quality tool in maintaining the tritium monitors at LANL

Calibration strategies for the Cherenkov Telescope Array

Science.gov (United States)

Gaug, Markus; Berge, David; Daniel, Michael; Doro, Michele; Förster, Andreas; Hofmann, Werner; Maccarone, Maria C.; Parsons, Dan; de los Reyes Lopez, Raquel; van Eldik, Christopher

2014-08-01

The Central Calibration Facilities workpackage of the Cherenkov Telescope Array (CTA) observatory for very high energy gamma ray astronomy defines the overall calibration strategy of the array, develops dedicated hardware and software for the overall array calibration and coordinates the calibration efforts of the different telescopes. The latter include LED-based light pulsers, and various methods and instruments to achieve a calibration of the overall optical throughput. On the array level, methods for the inter-telescope calibration and the absolute calibration of the entire observatory are being developed. Additionally, the atmosphere above the telescopes, used as a calorimeter, will be monitored constantly with state-of-the-art instruments to obtain a full molecular and aerosol profile up to the stratosphere. The aim is to provide a maximal uncertainty of 10% on the reconstructed energy-scale, obtained through various independent methods. Different types of LIDAR in combination with all-sky-cameras will provide the observatory with an online, intelligent scheduling system, which, if the sky is partially covered by clouds, gives preference to sources observable under good atmospheric conditions. Wide-field optical telescopes and Raman Lidars will provide online information about the height-resolved atmospheric extinction, throughout the field-of-view of the cameras, allowing for the correction of the reconstructed energy of each gamma-ray event. The aim is to maximize the duty cycle of the observatory, in terms of usable data, while reducing the dead time introduced by calibration activities to an absolute minimum.

Airborne Laser Polarization Sensor

Science.gov (United States)

Kalshoven, James, Jr.; Dabney, Philip

1991-01-01

Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

Test surfaces useful for calibration of surface profilometers

Science.gov (United States)

Yashchuk, Valeriy V; McKinney, Wayne R; Takacs, Peter Z

2013-12-31

The present invention provides for test surfaces and methods for calibration of surface profilometers, including interferometric and atomic force microscopes. Calibration is performed using a specially designed test surface, or the Binary Pseudo-random (BPR) grating (array). Utilizing the BPR grating (array) to measure the power spectral density (PSD) spectrum, the profilometer is calibrated by determining the instrumental modulation transfer.

Regulatory requirements and quality assurance of radiation monitoring instruments

International Nuclear Information System (INIS)

Narasimharao, K.L.; Sharma, Ranjit

2005-01-01

The successful utilisation of radiation sources in the fields of medicine and industry requires the accurate measurement of activity, exposure rate and dose. Many varieties of instruments are in use for measurement of these parameters and new ones are being developed. The criteria for the design of the radiation monitoring instrument include the type and intensity of the radiation, purpose of measurement and ruggedness of the instrument. Quality and reliability of radiation monitoring instruments ensure that individuals are adequately protected. Accuracy, response time and ruggedness are required to be as per the approved/ prescribed guidelines. Regulatory authorities outline the design and performance criteria for radiation monitoring instruments and prescribe the recommendations of international agencies such as IAEA, ICRU and ISO for radiological measurement assurance programme. National Standards Laboratories all over the world prescribe procedures for calibration of various radiation monitoring instruments. The instruments should be calibrated as per these guidelines and should be traceable to national standards. The calibration traceable to national/ international standards and documentation as well as limits stipulated by the competent authority ensures the expected performance of the instrument. (author)

Design and construction of the POLAR detector

OpenAIRE

Produit, N.; Bao, T. W.; Batsch, T.; Bernasconi, T.; Britvich, I.; Cadoux, F.; Cernuda, I.; Chai, J. Y.; Dong, Y. W.; Gauvin, N.; Hajdas, W.; Kole, M.; Kong, M. N.; Kramert, R.; Li, L.

2017-01-01

The POLAR detector is a space based Gamma Ray Burst (GRB) polarimeter with a wide field of view, which covers almost half the sky. The instrument uses Compton scattering of gamma rays on a plastic scintillator hodoscope to measure the polarization of the incoming photons. The instrument has been successfully launched on board of the Chinese space laboratory Tiangong~2 on September 15, 2016. The construction of the instrument components is described in this article. Details are provided on pro...

Simulation of a room for neutron instrument calibration at LCR/UERJ

International Nuclear Information System (INIS)

Medeiros, M.P.C.; Estrada, J.J.S.; Gomes, R.G.; Santos, R.F.G.; Leite, S.P.; Alves, C.F.E.; Rebello, W.F.; Almeida, C.E. de

2013-01-01

In this work the MCNPX code was used to design a calibrating room for neutron detectors to be implemented in the Laboratorio de Ciencias Radiologicas of UERJ. The calibration room containing a neutron irradiator with a 241 Am-Be source, a linear positioning system, radiation detectors and a shadow cone was modeled. The ambient dose equivalent rate, ııı ∗ ı10ı, in adjacent to the calibration room areas, as well as neutron scattering caused by the room itself were calculated. Using an occupancy factor of 1/16 for all adjacent areas, 3.8 cm of 5% borated polyethylene or 5.5 cm of concrete for shielding is enough to satisfy radiation safety requirements. (author)

The Gaia spectrophotometric standard stars survey: II. Instrumental effects of six ground-based observing campaigns

Science.gov (United States)

Altavilla, G.; Marinoni, S.; Pancino, E.; Galleti, S.; Ragaini, S.; Bellazzini, M.; Cocozza, G.; Bragaglia, A.; Carrasco, J. M.; Castro, A.; Di Fabrizio, L.; Federici, L.; Figueras, F.; Gebran, M.; Jordi, C.; Masana, E.; Schuster, W.; Valentini, G.; Voss, H.

2015-08-01

The Gaia SpectroPhotometric Standard Stars (SPSS) survey started in 2006, was awarded almost 450 observing nights and accumulated almost 100 000 raw data frames with both photometric and spectroscopic observations. Such large observational effort requires careful, homogeneous, and automatic data reduction and quality control procedures. In this paper, we quantitatively evaluate instrumental effects that might have a significant (i.e., ≥ 1 %) impact on the Gaia SPSS flux calibration. The measurements involve six different instruments, monitored over the eight years of observations dedicated to the Gaia flux standards campaigns: DOLORES@TNG in La Palma, EFOSC2@NTT and ROSS@REM in La Silla, CAFOS@2.2 m in Calar Alto, BFOSC@Cassini in Loiano, and LaRuca@1.5 m in San Pedro Mártir. We examine and quantitatively evaluate the following effects: CCD linearity and shutter times, calibration frames stability, lamp flexures, second order contamination, light polarization, and fringing. We present methods to correct for the relevant effects which can be applied to a wide range of observational projects at similar instruments. Based on data obtained with BFOSC@Cassini in Loiano, Italy; EFOSC2@NTT in La Silla, Chile; DOLORES@TNG in La Palma, Spain; CAFOS@2.2 m in Calar Alto, Spain; LaRuca@1.5 m in San Pedro Mártir, Mexico (see acknowledgements for more details).

Calibration Standards for Surface Topography Measuring Systems down to Nanometric Range

DEFF Research Database (Denmark)

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

compression and injection moulded plastic negatives and Ni-negatives have been made from which again Ni-positives were produced. The replication processes showed negligible deviations from the Pt and Pa values compared to the primary standards. An important prerequisite is the cleanliness of the surfaces......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...

Model Robust Calibration: Method and Application to Electronically-Scanned Pressure Transducers

Science.gov (United States)

Walker, Eric L.; Starnes, B. Alden; Birch, Jeffery B.; Mays, James E.

2010-01-01

This article presents the application of a recently developed statistical regression method to the controlled instrument calibration problem. The statistical method of Model Robust Regression (MRR), developed by Mays, Birch, and Starnes, is shown to improve instrument calibration by reducing the reliance of the calibration on a predetermined parametric (e.g. polynomial, exponential, logarithmic) model. This is accomplished by allowing fits from the predetermined parametric model to be augmented by a certain portion of a fit to the residuals from the initial regression using a nonparametric (locally parametric) regression technique. The method is demonstrated for the absolute scale calibration of silicon-based pressure transducers.

Lyman alpha SMM/UVSP absolute calibration and geocoronal correction

Science.gov (United States)

Fontenla, Juan M.; Reichmann, Edwin J.

1987-01-01

Lyman alpha observations from the Ultraviolet Spectrometer Polarimeter (UVSP) instrument of the Solar Maximum Mission (SMM) spacecraft were analyzed and provide instrumental calibration details. Specific values of the instrument quantum efficiency, Lyman alpha absolute intensity, and correction for geocoronal absorption are presented.

Calibration and validation of the advanced E-Region Wind Interferometer

Directory of Open Access Journals (Sweden)

S. K. Kristoffersen

2013-07-01

Full Text Available The advanced E-Region Wind Interferometer (ERWIN II combines the imaging capabilities of a CCD detector with the wide field associated with field-widened Michelson interferometry. This instrument is capable of simultaneous multi-directional wind observations for three different airglow emissions (oxygen green line (O(1S at a height of ~97 km, the PQ(7 and P(7 emission lines in the O2(0–1 atmospheric band at ~93 km and P1(3 emission line in the (6, 2 hydroxyl Meinel band at ~87 km on a three minute cadence. In each direction, for 45 s measurements for typical airglow volume emission rates, the instrument is capable of line-of-sight wind precisions of ~1 m s−1 for hydroxyl and O(1S and ~4 m s−1 for O2. This precision is achieved using a new data analysis algorithm which takes advantage of the imaging capabilities of the CCD detector along with knowledge of the instrument phase variation as a function of pixel location across the detector. This instrument is currently located in Eureka, Nunavut as part of the Polar Environment Atmospheric Research Laboratory (PEARL (80°N, 86° W. The details of the physical configuration, the data analysis algorithm, the measurement calibration and validation of the observations from December 2008 and January 2009 are described. Field measurements which demonstrate the capabilities of this instrument are presented. To our knowledge, the wind determinations with this instrument are the most accurate and have the highest observational cadence for airglow wind observations of this region of the atmosphere and match the capabilities of other wind-measuring techniques.

In-core flow measurement and calibration of gags using on-load instrumented stringers in a C.A.G.R. at Hinkley Point 'B'

International Nuclear Information System (INIS)

Harrison, W.E.; Carrick, I.H.

1982-06-01

The initial fuel loading of the first CAGR at Hinkley Point included 5 specially instrumented stringers (OLIS) each containing a flow-measuring venturi and additional thermocouples. Venturi absolute and differential pressures were measured by transducers mounted on the pile-cap. Transducers and thermocouples were routed to a computer/logger and processed into stringer performance data. The venturi was engineered to comply closely with appropriate British Standards but compromises were made to minimise interaction with other functions of the OLIS plug unit, justifying rig calibration of venturis to check for deviation in behaviour. High accuracy and reliability of the flow measuring system were established by thorough commissioning procedures. The transducers were selected for low sensitivity to their operational environment. Nevertheless calibration of all transducers was carried out both in laboratory and in-situ. Errors introduced by signal processing were identified and zero drift monitored. Pipe-runs were scrupulously leak-tested and leak sensitivity was evaluated. After one year re-calibration and recommissioning gave confidence of long term stability. Measurements of stringer behaviour were collected in a series of tests spanning the full range of both the setting of the channel flow control gags and the reactor power. Throughout these tests comprehensive monitoring, with intercalibration between the OLIS and comparison with installed reactor instrumentation has quantified residual error. These measurements were used to check the theoretical model used by the station for channel flow assessment. The excellent agreement obtained justified proceeding to the derivation of a universal gag resistance calibration applying to all power levels. In performance tests aimed at evaluation of overall generating efficiency, the theoretical model was used to make accurate estimates of reactor power and flow which agreed well with estimates based directly on further OLIS

Calibration of Raman lidar water vapor profiles by means of AERONET photometer observations and GDAS meteorological data

Science.gov (United States)

Dai, Guangyao; Althausen, Dietrich; Hofer, Julian; Engelmann, Ronny; Seifert, Patric; Bühl, Johannes; Mamouri, Rodanthi-Elisavet; Wu, Songhua; Ansmann, Albert

2018-05-01

We present a practical method to continuously calibrate Raman lidar observations of water vapor mixing ratio profiles. The water vapor profile measured with the multiwavelength polarization Raman lidar class="text">PollyXT is calibrated by means of co-located AErosol RObotic NETwork (AERONET) sun photometer observations and Global Data Assimilation System (GDAS) temperature and pressure profiles. This method is applied to lidar observations conducted during the Cyprus Cloud Aerosol and Rain Experiment (CyCARE) in Limassol, Cyprus. We use the GDAS temperature and pressure profiles to retrieve the water vapor density. In the next step, the precipitable water vapor from the lidar observations is used for the calibration of the lidar measurements with the sun photometer measurements. The retrieved calibrated water vapor mixing ratio from the lidar measurements has a relative uncertainty of 11 % in which the error is mainly caused by the error of the sun photometer measurements. During CyCARE, nine measurement cases with cloud-free and stable meteorological conditions are selected to calculate the precipitable water vapor from the lidar and the sun photometer observations. The ratio of these two precipitable water vapor values yields the water vapor calibration constant. The calibration constant for the class="text">PollyXT Raman lidar is 6.56 g kg-1 ± 0.72 g kg-1 (with a statistical uncertainty of 0.08 g kg-1 and an instrumental uncertainty of 0.72 g kg-1). To check the quality of the water vapor calibration, the water vapor mixing ratio profiles from the simultaneous nighttime observations with Raman lidar and Vaisala radiosonde sounding are compared. The correlation of the water vapor mixing ratios from these two instruments is determined by using all of the 19 simultaneous nighttime measurements during CyCARE. Excellent agreement with the slope of 1.01 and the R2 of 0.99 is found. One example is presented to demonstrate the full potential of a well-calibrated Raman

In-situ calibration: migrating control system IP module calibration from the bench to the storage ring

International Nuclear Information System (INIS)

Weber, Jonah M.; Chin, Michael

2002-01-01

The Control System for the Advanced Light Source (ALS) at Lawrence Berkeley National Lab (LBNL) uses in-house designed IndustryPack(registered trademark) (IP) modules contained in compact PCI (cPCI) crates with 16-bit analog I/O to control instrumentation. To make the IP modules interchangeable, each module is calibrated for gain and offset compensation. We initially developed a method of verifying and calibrating the IP modules in a lab bench test environment using a PC with LabVIEW. The subsequent discovery that the ADCs have significant drift characteristics over periods of days of installed operation prompted development of an ''in-situ'' calibration process--one in which the IP modules can be calibrated without removing them from the cPCI crates in the storage ring. This paper discusses the original LabVIEW PC calibration and the migration to the proposed in-situ EPICS control system calibration

Fundamental limits of radio interferometers: calibration and source parameter estimation

OpenAIRE

Trott, Cathryn M.; Wayth, Randall B.; Tingay, Steven J.

2012-01-01

We use information theory to derive fundamental limits on the capacity to calibrate next-generation radio interferometers, and measure parameters of point sources for instrument calibration, point source subtraction, and data deconvolution. We demonstrate the implications of these fundamental limits, with particular reference to estimation of the 21cm Epoch of Reionization power spectrum with next-generation low-frequency instruments (e.g., the Murchison Widefield Array -- MWA, Precision Arra...

Design and construction of the POLAR detector

Science.gov (United States)

Produit, N.; Bao, T. W.; Batsch, T.; Bernasconi, T.; Britvich, I.; Cadoux, F.; Cernuda, I.; Chai, J. Y.; Dong, Y. W.; Gauvin, N.; Hajdas, W.; Kole, M.; Kong, M. N.; Kramert, R.; Li, L.; Liu, J. T.; Liu, X.; Marcinkowski, R.; Orsi, S.; Pohl, M.; Rapin, D.; Rybka, D.; Rutczynska, A.; Shi, H. L.; Socha, P.; Sun, J. C.; Song, L. M.; Szabelski, J.; Traseira, I.; Xiao, H. L.; Wang, R. J.; Wen, X.; Wu, B. B.; Zhang, L.; Zhang, L. Y.; Zhang, S. N.; Zhang, Y. J.; Zwolinska, A.

2018-01-01

The POLAR detector is a space based Gamma Ray Burst (GRB) polarimeter with a wide field of view, which covers almost half the sky. The instrument uses Compton scattering of gamma rays on a plastic scintillator hodoscope to measure the polarization of the incoming photons. The instrument has been successfully launched on board of the Chinese space laboratory Tiangong 2 on September 15, 2016. The construction of the instrument components is described in this article. Details are provided on problems encountered during the construction phase and their solutions. Initial performance of the instrument in orbit is as expected from ground tests and Monte Carlo simulation.

Improvement of gamma calibration procedures with commercial management software

International Nuclear Information System (INIS)

Lucena, Rodrigo F.; Potiens, Maria da Penha A.; Santos, Gelson P.; Vivolo, Vitor

2007-01-01

In this work, the gamma calibration procedure of the Instruments Calibration Laboratory (LCI) of the IPEN-CNEN-SP was improved with the use of the commercial management software Autolab TM from Automa Company. That software was adapted for our specific use in the calibration procedures. The evaluation of the uncertainties in gamma calibration protocol was improved by the LCI staff and yet the all worksheets and final calibration report lay-out was developed in commercial software like Excell TM and Word TM from Microsft TM . (author)

Spectrophotometric calibration system for DECam

Science.gov (United States)

Rheault, J.-P.; DePoy, D. L.; Marshall, J. L.; Prochaska, T.; Allen, R.; Wise, J.; Martin, E.; Williams, P.

2012-09-01

We describe a spectrophotometric calibration system that is being implemented as part of the DES DECam project at the Blanco 4 meter at CTIO. Our calibration system uses a 1nm wide tunable source to measure the instrumental response function of the telescope optics and detector from 300nm up to 1100nm. This calibration will be performed regularly to monitor any change in the transmission function of the telescope during the 5 year survey. The system consists of a monochromator based tunable light source that provides illumination on a dome flat that is monitored by calibrated photodiodes that allow us to measure the telescope throughput as a function of wavelength. Our system has a peak output power of 2 mW, equivalent to a flux of approximately 800 photons/s/pixel on DECam.

Cassini Ion Mass Spectrometer Peak Calibrations from Statistical Analysis of Flight Data

Science.gov (United States)

Woodson, A. K.; Johnson, R. E.

2017-12-01

The Cassini Ion Mass Spectrometer (IMS) is an actuating time-of-flight (TOF) instrument capable of resolving ion mass, energy, and trajectory over a field of view that captures nearly the entire sky. One of three instruments composing the Cassini Plasma Spectrometer, IMS sampled plasma throughout the Kronian magnetosphere from 2004 through 2012 when it was permanently disabled due to an electrical malfunction. Initial calibration of the flight instrument at Southwest Research Institute (SwRI) was limited to a handful of ions and energies due to time constraints, with only about 30% of planned measurements carried out prior to launch. Further calibration measurements were subsequently carried out after launch at SwRI and Goddard Space Flight Center using the instrument prototype and engineering model, respectively. However, logistical differences among the three calibration efforts raise doubts as to how accurately the post-launch calibrations describe the behavior of the flight instrument. Indeed, derived peak parameters for some ion species differ significantly from one calibration to the next. In this study we instead perform a statistical analysis on 8 years of flight data in order to extract ion peak parameters that depend only on the response of the flight instrument itself. This is accomplished by first sorting the TOF spectra based on their apparent compositional similarities (e.g. primarily water group ions, primarily hydrocarbon ions, etc.) and normalizing each spectrum. The sorted, normalized data are then binned according to TOF, energy, and counts in order to generate energy-dependent probability density maps of each ion peak contour. Finally, by using these density maps to constrain a stochastic peak fitting algorithm we extract confidence intervals for the model parameters associated with various measured ion peaks, establishing a logistics-independent calibration of the body of IMS data gathered over the course of the Cassini mission.

Herschel SPIRE FTS spectral line source calibrators

DEFF Research Database (Denmark)

Hopwood, Rosalind; Polehampton, Edward; Valtchanov, Ivan

2015-01-01

We present a summary of the Herschel SPIRE/FTS calibration programme to monitor the repeatability of spectral lines. Observations of planetary nebulae and post-AGB stars are used to assess repeatability and model the asymmetry of the instrument line shape.......We present a summary of the Herschel SPIRE/FTS calibration programme to monitor the repeatability of spectral lines. Observations of planetary nebulae and post-AGB stars are used to assess repeatability and model the asymmetry of the instrument line shape....

Dose calibrator user and quality control guide

International Nuclear Information System (INIS)

Blanchis, Philippe; Amiot, Marie-Noelle; Moune, Muriel; Bellanger, Anne-Christine; Chauvenet, Bruno; Verdeau, Eric; Gardin, Isabelle; Martineau, Antoine; Ricard, Marcel; Caselles, Olivier; Guilhem, Marie-Therese; Hapdey, Sebastien; Lisbona, Albert; Bonnot-Lours, Sophie; Dumont, Agnes; Lemercier, Valerie; Rizzo-Padoin, Nathalie

2006-06-01

This document is a practical guide for the use and control of dose calibrators which are instruments used for radioactivity measurements. After a recall of the calibrator operation principle, the authors describe all the operations performed on this apparatus all along its lifetime: controls to be performed for device acceptance, aspects to be addressed during installation, controls to be performed before any use, daily controls, more detailed controls, and operations to be performed for maintenance, in case of dysfunctions or for re-calibration

Development of a calibration system for surface contamination monitors

International Nuclear Information System (INIS)

Marechal, M.H.H.; Barbosa, M.P.

1992-01-01

A calibration system for surface contamination monitors is developed, aiming supply the existence demand of these instruments. A experimental arrangement and a methodology are described. The advantages of use this system for calibration routine optimization are also discussed. (C.G.C.)

Method of calibration for portable detectors of ionizing radiation

International Nuclear Information System (INIS)

Leal, Carlos; Carrizales, Lila; Guacaran, Douglas; Moreno, Ailed; Duran, Jose

2008-01-01

Full text: The LSCD is beginning a process of accreditation by the national authority of Venezuela (CENCAMER), so we felt the need to modify existing protocols calibration, suggested by the IAEA (Technical Reports Series No 133) to be adjusted in accordance with international standards of ISO 17025 EA-4/02 and Mexican standard NOM-021-NUCL-2002, adapting the calibration procedure of portable radiation detectors to those standards. The procedure used in the LSCD, conducts an intercomparison between measures between the standard reference and to calibrate the instrument, thus verifying the correct operation of the equipment and its usefulness to the individual or environmental radiation monitoring, not to exceed the limits primary for the public and occupationally Staff Exposed (POE), and propose a simple way to perform this calibration procedure and comply with the standard international and national standards, ensuring the proper functioning of the instruments calibrated. One of the calculations that has proven to be a useful tool in the verification of the conditions of operating the same, it is uncertainty, this procedure allows to characterize the response of individual detector, depending on the constraints specified by the manufacturer, to optimize the calibration is necessary to consider the multiple factors that can affect the measure and evaluate the response of the same, so it is vitally important estimating the typical uncertainty associated with the calibration technique employed, but this calculation is not trivial, depends on the type of detector found usually between 5% to 20%, both in uncertainty as the linearity, which are the parameters that are set to consider an instrument in good or bad condition. Typical are calibrated are: monitors air Geiger-Muller, Ionization cameras, detector of Neutron's, Proportional Counter, Personal dosimeters. (author)

Construction, Test And Calibration of the GLAST Silicon Tracker

Energy Technology Data Exchange (ETDEWEB)

Sgro, C.; Atwood, W.B.; Baldini, L.; Barbiellini, G.; Bellazzini, R.; Belli, F.; Bonamente, E.; Borden, T.; Bregeon, J.; Brez, A.; Brigida, M.; Caliandro, G.A.; Cecchi, C.; Cohen-Tanugi, J.; De Angelis, A.; Drell, P.; Favuzzi, C.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Germani, S.; /INFN, Pisa /Pisa U. /UC, Santa Cruz /INFN, Trieste /Rome U.,Tor Vergata /SLAC /INFN, Bari /Bari U. /INFN, Perugia /Perugia U. /Udine U. /Hiroshima U. /Maryland U., JCA /Tokyo Inst. Tech. /JAXA, Sagamihara /INFN, Padua /Padua U. /Pisa, Scuola Normale Superiore /NASA, Goddard

2009-06-05

The Gamma-ray Large Area Space Telescope represents a great advance in space application of silicon detectors. With a surface of 80 m{sup 2} and about 1 M readout channels it is the largest silicon tracker ever built for a space experiment. GLAST is an astro-particle mission that will study the mostly unexplored, high energy (20 MeV-300 GeV) spectrum coming from active sources or diffused in the Universe. The detector integration and test phase is complete. The full instrument underwent environmental testing and the spacecraft integration phase has just started: the launch is foreseen in late 2007. In the meanwhile the spare modules are being used for instrument calibration and performance verification employing the CERN accelerator complex. A Calibration Unit has been exposed to photon, electron and hadron beams from a few GeV up to 300 GeV. We report on the status of the instrument and on the calibration campaign.

One photon exchange processes and the calibration of polarization of high energy protons

International Nuclear Information System (INIS)

Margolis, B.; Thomas, G.H.

1978-01-01

Polarization phenomena in small momentum transfer high energy one-photon exchange processes in the reaction p + A → X + A where A is a complex nucleus and X is anything are examined. It is shown that these polarizations can be related directly to photoproduction polarization effects in the reaction γ + p → X at low energies. Explicit formulae are written for polarization effects in the case where X → π 0 + p

Calibration and intercomparison methods of dose calibrators used in nuclear medicine facilities; Metodos de calibracao e de intercomparacao de calibradores de dose utilizados em servicos de medicina nuclear

Energy Technology Data Exchange (ETDEWEB)

Costa, Alessandro Martins da

1999-07-01

Dose calibrators are used in most of the nuclear medicine facilities to determine the amount of radioactivity administered to a patient in a particular investigation or therapeutic procedure. It is therefore of vital importance that the equipment used presents good performance and is regular;y calibrated at a authorized laboratory. This occurs of adequate quality assurance procedures are carried out. Such quality control tests should be performed daily, other biannually or yearly, testing, for example, its accuracy and precision, the reproducibility and response linearity. In this work a commercial dose calibrator was calibrated with solution of radionuclides used in nuclear medicine. Simple instrument tests, such as response linearity and the response variation of the source volume increase at a constant source activity concentration, were performed. This instrument can now be used as a working standard for calibration of other dose calibrators/ An intercomparison procedure was proposed as a method of quality control of dose calibrators used in nuclear medicine facilities. (author)

W-026, health physics instrumentation operational test report

International Nuclear Information System (INIS)

Hackworth, M.F.

1998-01-01

This report documents the testing of the Health Physics Instrumentation associated with phase 2 and 3 start-up of Project W-026, WRAP. The Health Physics Instrumentation includes: Alpha and Beta Continuous Air Monitors (CAMS), Personnel Contamination Monitors (PCMs), Gamma Area Radiation Monitors (ARMs), Criticality Monitors, Alpha and Beta Smear Sample Counters, Portable Friskers, and Operator Breathing Zone Air Samplers. This OTR will cover only the Health Physics Instrumentation that was tested under the Operational test Plan for Health Physics Instrumentation (Phase 2 and 3). That instrumentation included: Alpha CAMS, Beta CAMs and ARMs located in rooms 107 and 113 of 2336-W. The remaining Health Physics Instrumentation that will be used for phase 2 and 3 start-up is tested during calibrations. These calibrations are outside the scope of the Operational Test Plan

CMB polarization at large angular scales: Data analysis of the POLAR experiment

International Nuclear Information System (INIS)

O'Dell, Christopher W.; Keating, Brian G.; Oliveira-Costa, Angelica de; Tegmark, Max; Timbie, Peter T.

2003-01-01

The coming flood of cosmic microwave background (CMB) polarization experiments, spurred by the recent detection of CMB polarization by the DASI and WMAP instruments, will be confronted by many new analysis tasks specific to polarization. For the analysis of CMB polarization data sets, the devil is truly in the details. With this in mind, we present details of the data analysis for the POLAR experiment, which recently led to the tightest upper limits on the polarization of the cosmic microwave background radiation at large angular scales. We discuss the data selection process, map-making algorithms, offset removal, and likelihood analysis which were used to find upper limits on the polarization. Stated using the modern convention for reporting CMB Stokes parameters, these limits are 5.0 μK on both E- and B-type polarization at 95% confidence. Finally, we discuss simulations used to test our analysis techniques and to probe the fundamental limitations of the experiment

Calibration of a spinner anemometer for yaw misalignment measurements

DEFF Research Database (Denmark)

Friis Pedersen, Troels; Demurtas, Giorgio; Zahle, Frederik

2015-01-01

constant, k1, mainly affects the measurement of wind speed. The ratio between the two constants, kα = k2/k1, however, only affects the measurement of flow angles. The calibration of kα is thus a basic calibration of the spinner anemometer. Theoretical background for the non-linear calibration is derived......The spinner anemometer is an instrument for yaw misalignment measurements without the drawbacks of instruments mounted on the nacelle top. The spinner anemometer uses a non-linear conversion algorithm that converts the measured wind speeds by three sonic sensors on the spinner to horizontal wind...... from the generic spinner anemometer conversion algorithm. Five different methods were evaluated for calibration of a spinner anemometer on a 500 kW wind turbine. The first three methods used rotor yaw direction as reference angular, while the wind turbine, was yawed in and out of the wind. The fourth...

The Breakthrough Listen Search for Intelligent Life: Data Calibration using Pulsars

Science.gov (United States)

Brinkman-Traverse, Casey Lynn; Gajjar, Vishal; BSRC

2018-01-01

The ability to distinguish ET signals requires a deep understanding of the radio telescopes with which we search; therefore, before we observe stars of interest, the Breathrough Listen scientists at Berkeley SETI Research Center first observe a Pulsar with well-documented flux and polarization properties. The process of calibrating the flux and polarization is a lengthy process by hand, so we produced a pipeline code that will automatically calibrate the pulsar in under an hour. Using PSRCHIVE the code coherently dedisperses the pulsed radio signals, and then calibrates the flux using observation files with a noise diode turning on and off. The code was developed using PSR B1937+ 21 and is primarily used on PSR B0329+54. This will expedite the process of assessing the quality of data collected from the Green Bank Telescope in West Virginia and will allow us to more efficiently find life beyond Planet Earth. Additionally, the stability of the B0329+54 calibration data will allow us to analyze data taken on FRB's with confidence of its cosmic origin.

Instrumentation & Data Acquisition System (D AS) Engineer

Science.gov (United States)

Jackson, Markus Deon

2015-01-01

The primary job of an Instrumentation and Data Acquisition System (DAS) Engineer is to properly measure physical phenomenon of hardware using appropriate instrumentation and DAS equipment designed to record data during a specified test of the hardware. A DAS system includes a CPU or processor, a data storage device such as a hard drive, a data communication bus such as Universal Serial Bus, software to control the DAS system processes like calibrations, recording of data and processing of data. It also includes signal conditioning amplifiers, and certain sensors for specified measurements. My internship responsibilities have included testing and adjusting Pacific Instruments Model 9355 signal conditioning amplifiers, writing and performing checkout procedures, writing and performing calibration procedures while learning the basics of instrumentation.

Improved Detection System Description and New Method for Accurate Calibration of Micro-Channel Plate Based Instruments and Its Use in the Fast Plasma Investigation on NASA's Magnetospheric MultiScale Mission

Science.gov (United States)

Gliese, U.; Avanov, L. A.; Barrie, A. C.; Kujawski, J. T.; Mariano, A. J.; Tucker, C. J.; Chornay, D. J.; Cao, N. T.; Gershman, D. J.; Dorelli, J. C.;

Comprehensive Calibration and Validation Site for Information Remote Sensing

Science.gov (United States)

Li, C. R.; Tang, L. L.; Ma, L. L.; Zhou, Y. S.; Gao, C. X.; Wang, N.; Li, X. H.; Wang, X. H.; Zhu, X. H.

2015-04-01

As a naturally part of information technology, Remote Sensing (RS) is strongly required to provide very precise and accurate information product to serve industry, academy and the public at this information economic era. To meet the needs of high quality RS product, building a fully functional and advanced calibration system, including measuring instruments, measuring approaches and target site become extremely important. Supported by MOST of China via national plan, great progress has been made to construct a comprehensive calibration and validation (Cal&Val) site, which integrates most functions of RS sensor aviation testing, EO satellite on-orbit caration and performance assessment and RS product validation at this site located in Baotou, 600km west of Beijing. The site is equipped with various artificial standard targets, including portable and permanent targets, which supports for long-term calibration and validation. A number of fine-designed ground measuring instruments and airborne standard sensors are developed for realizing high-accuracy stepwise validation, an approach in avoiding or reducing uncertainties caused from nonsynchronized measurement. As part of contribution to worldwide Cal&Val study coordinated by CEOS-WGCV, Baotou site is offering its support to Radiometric Calibration Network of Automated Instruments (RadCalNet), with an aim of providing demonstrated global standard automated radiometric calibration service in cooperation with ESA, NASA, CNES and NPL. Furthermore, several Cal&Val campaigns have been performed during the past years to calibrate and validate the spaceborne/airborne optical and SAR sensors, and the results of some typical demonstration are discussed in this study.

A method for the accurate determination of the polarization of a neutron beam using a polarized 3He spin filter

International Nuclear Information System (INIS)

Greene, G.L.; Thompson, A.K.; Dewey, M.S.

1995-01-01

A new method for the accurate determination of the degree of polarization of a neutron beam which has been polarized by transmission through a spin polarized 3 He cell is given. The method does not require the use of an analyzer or spin flipper nor does it require an accurate independent determination of the 3 He polarization. The method provides a continuous on-line determination of the neutron polarization. The method may be of use in the accurate determination of correlation coefficients in neutron beta decay which provide a test of the standard model for the electroweak interaction. The method may also provide an accurate procedure for the calibration of polarized 3 He targets used in medium and high energy scattering experiments. ((orig.))

Calibration of RB reactor power

International Nuclear Information System (INIS)

Sotic, O.; Markovic, H.; Ninkovic, M.; Strugar, P.; Dimitrijevic, Z.; Takac, S.; Stefanovic, D.; Kocic, A.; Vranic, S.

1976-09-01

The first and only calibration of RB reactor power was done in 1962, and the obtained calibration ratio was used irrespective of the lattice pitch and core configuration. Since the RB reactor is being prepared for operation at higher power levels it was indispensable to reexamine the calibration ratio, estimate its dependence on the lattice pitch, critical level of heavy water and thickness of the side reflector. It was necessary to verify the reliability of control and dosimetry instruments, and establish neutron and gamma dose dependence on reactor power. Two series of experiments were done in June 1976. First series was devoted to tests of control and dosimetry instrumentation and measurements of radiation in the RB reactor building dependent on reactor power. Second series covered measurement of thermal and epithermal neuron fluxes in the reactor core and calculation of reactor power. Four different reactor cores were chosen for these experiments. Reactor pitches were 8, 8√2, and 16 cm with 40, 52 and 82 fuel channels containing 2% enriched fuel. Obtained results and analysis of these results are presented in this document with conclusions related to reactor safe operation

Calibration of a leak detection spectrometer; Calibration d'un spectrometre detecteur de fuites

Energy Technology Data Exchange (ETDEWEB)

Geller, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper describes a study of the possible methods for calibrating a leak detection spectrometer, and the estimation of outputs from the leaks is considered. With this in mind the question of sensitivity of leak detection is tackled on a very general level; first the sensitivity of the isolated instrument is determined, and then the sensitivity of an instrument connected to an installation where leaks may be suspected. Finally, practical solutions are proposed. (author) [French] Dans cet article, nous etudions les methodes possibles de calibration d'un spectrometre detecteur de fuites et nous envisageons l'evaluation des debits de fuites trouves. Pour cela, nous abordons la notion de sensibilite de la detection de fuite sur un plan tres general; d'abord nous determinons la sensibilite de l'appareil isole, ensuite la sensibilite d'un appareil connecte sur une installation ou l'on cherche les fuites. Enfin, nous preconisons des solutions pratiques. (auteur)

Automated Calibration of Dosimeters for Diagnostic Radiology

International Nuclear Information System (INIS)

Romero Acosta, A.; Gutierrez Lores, S.

2015-01-01

Calibration of dosimeters for diagnostic radiology includes current and charge measurements, which are often repetitive. However, these measurements are usually done using modern electrometers, which are equipped with an RS-232 interface that enables instrument control from a computer. This paper presents an automated system aimed to the measurements for the calibration of dosimeters used in diagnostic radiology. A software application was developed, in order to achieve the acquisition of the electric charge readings, measured values of the monitor chamber, calculation of the calibration coefficient and issue of a calibration certificate. A primary data record file is filled and stored in the computer hard disk. The calibration method used was calibration by substitution. With this system, a better control over the calibration process is achieved and the need for human intervention is reduced. the automated system will be used in the calibration of dosimeters for diagnostic radiology at the Cuban Secondary Standard Dosimetry Laboratory of the Center for Radiation Protection and Hygiene. (Author)

Online Resource for Earth-Observing Satellite Sensor Calibration

Science.gov (United States)

McCorkel, J.; Czapla-Myers, J.; Thome, K.; Wenny, B.

2015-01-01

The Radiometric Calibration Test Site (RadCaTS) at Railroad Valley Playa, Nevada is being developed by the University of Arizona to enable improved accuracy and consistency for airborne and satellite sensor calibration. Primary instrumentation at the site consists of ground-viewing radiometers, a sun photometer, and a meteorological station. Measurements made by these instruments are used to calculate surface reflectance, atmospheric properties and a prediction for top-of-atmosphere reflectance and radiance. This work will leverage research for RadCaTS, and describe the requirements for an online database, associated data formats and quality control, and processing levels.

Stand-alone polarization-modulation infrared reflection absorption spectroscopy instrument optimized for the study of catalytic processes at elevated pressures

Science.gov (United States)