The setting for ground based augmentation system station

Science.gov (United States)

Ni, Yude; Liu, Ruihua

2007-11-01

Based on the minimum field strength requirement within the whole GBAS service volume, this paper performs nominal link power budget for GBAS VHF data broadcast (VDB) system, and the required power transmitted from VDB system is derived. The paper elaborates the requirement of Desired-to-Undesired (D/U) signal ratio for a specific VHF airborne receiver to ensure the normal operation by the test, and presents the experimental method and results for acquiring the D/U signal ratios. The minimum geographical separations among GBAS, VOR and ILS stations are calculated according to the specifications of these three kinds of navigation systems.

Software-Defined Ground Stations - Enhancing Multi-Mission Support, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR Phase 1 proposal to NASA requests $99,055.69 to enhance multiple mission support in ground stations through the use of software defined radios and virtual...

Observations of Upper Thermospheric Temperatures Using a Ground-Based Optical Instrument at the King Sejong Station, Antarctic

Directory of Open Access Journals (Sweden)

Jong-Kyun Chung

1998-06-01

Full Text Available We measured the terrestrial nightglow of OI 6300A in the thermosphere(~250km using a ground-based Fabry-Perot interferometer at the King Sejong Station, Antarctic from March through September, 1997. The King Sejong Station is located at high latitude geographically (62.22 deg S, 301.25 deg E but at mid-latitude geomagnetically (50.65 deg S, 7.51 deg E. It is therefore the strategic location to measure the temperatures of the thermosphere in the Southern Hemisphere associated with both solar and geomagnetic activities. In this study, we analyzed the observed temperatures in relation to F10.7 and Kp indices to examine the effect of the solar and the geomagnetic activities on high-latitude neutral thermosphere. During the observing period, the solar activity was at its minimum. The measured temperatures are usually in the range between about 600~1000 K with some seasonal variation and are higher than those predicted by semi-empirical model, VSH (Vector Spherical Harmonics and empirical model, MSIS (Mass-Spectrometer-Incoherent-Scatter-86.

Observations of Upper Thermospheric Temperatures Using a Ground-Based Optical Instrument at the King Sejong Station, Antarctic

Science.gov (United States)

Chung, Jong-Kyun; Won, Young-In; Lee, Bang Yong; Kim, Jhoon

1998-06-01

We measured the terrestrial nightglow of OI 6300A in the thermosphere(~250km) using a ground-based Fabry-Perot interferometer at the King Sejong Station, Antarctic from March through September, 1997. The King Sejong Station is located at high latitude geographically (62.22 deg S, 301.25 deg E) but at mid-latitude geomagnetically (50.65 deg S, 7.51 deg E). It is therefore the strategic location to measure the temperatures of the thermosphere in the Southern Hemisphere associated with both solar and geomagnetic activities. In this study, we analyzed the observed temperatures in relation to F10.7 and Kp indices to examine the effect of the solar and the geomagnetic activities on high-latitude neutral thermosphere. During the observing period, the solar activity was at its minimum. The measured temperatures are usually in the range between about 600~1000 K with some seasonal variation and are higher than those predicted by semi-empirical model, VSH (Vector Spherical Harmonics) and empirical model, MSIS (Mass-Spectrometer-Incoherent-Scatter)-86.

Public exposure to radio waves near GSM microcell and picocell base stations

International Nuclear Information System (INIS)

Cooper, T G; Mann, S M; Khalid, M; Blackwell, R P

2006-01-01

Exposures of the general public to radio waves at locations near 20 randomly selected GSM microcell and picocell base stations in the UK have been assessed in the context of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Compliance distances were calculated for the antennas of the base stations from their reported radiated powers. Under pessimistic assumptions that would maximise exposures, the minimum height at which the general public reference level could potentially be exceeded near any of the base station antennas was calculated to be 2.4 m above ground level. The power densities of the broadcast carriers transmitted by the base stations have been measured and scaled to include all other possible carriers. Exposures were generally in the range 0.002-2% of the ICNIRP general public reference level, and the greatest exposure quotient near any of the base stations was 8.6%. Exposures close to microcell base stations were found to be generally greater than those close to macrocell base stations

Application of ground-penetrating radar at McMurdo Station, Antarctica

Energy Technology Data Exchange (ETDEWEB)

Stefano, J.E.

1992-01-01

Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

Application of ground-penetrating radar at McMurdo Station, Antarctica

Energy Technology Data Exchange (ETDEWEB)

Stefano, J.E.

1992-05-01

Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

Application of ground-penetrating radar at McMurdo Station, Antarctica

International Nuclear Information System (INIS)

Stefano, J.E.

1992-01-01

Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station

Electromagnetic fields from base stations for cellular mobile telephones. Measurements around base stations in the Oslo area

International Nuclear Information System (INIS)

Hannevik, Merete

2000-01-01

Measurements of radio frequent radiation from base station antennas for cellular mobile telephony have been performed. Measurements were performed inside the buildings in the area just behind or below antennas mounted on the wall or rooftop on buildings and on the ground below tower-mounted antennas. Except from the area 2-3 meters just in front of the antennas the electrical field levels were well below the international guidelines. (Author)

Design of an MSAT-X mobile transceiver and related base and gateway stations

Science.gov (United States)

Fang, Russell J. F.; Bhaskar, Udaya; Hemmati, Farhad; Mackenthun, Kenneth M.; Shenoy, Ajit

This paper summarizes the results of a design study of the mobile transceiver, base station, and gateway station for NASA's proposed Mobile Satellite Experiment (MSAT-X). Major ground segment system design issues such as frequency stability control, modulation method, linear predictive coding vocoder algorithm, and error control technique are addressed. The modular and flexible transceiver design is described in detail, including the core, RF/IF, modem, vocoder, forward error correction codec, amplitude-companded single sideband, and input/output modules, as well as the flexible interface. Designs for a three-carrier base station and a 10-carrier gateway station are also discussed, including the interface with the controllers and with the public-switched telephone networks at the gateway station. Functional specifications are given for the transceiver, the base station, and the gateway station.

Design of an MSAT-X mobile transceiver and related base and gateway stations

Science.gov (United States)

Fang, Russell J. F.; Bhaskar, Udaya; Hemmati, Farhad; Mackenthun, Kenneth M.; Shenoy, Ajit

1987-01-01

This paper summarizes the results of a design study of the mobile transceiver, base station, and gateway station for NASA's proposed Mobile Satellite Experiment (MSAT-X). Major ground segment system design issues such as frequency stability control, modulation method, linear predictive coding vocoder algorithm, and error control technique are addressed. The modular and flexible transceiver design is described in detail, including the core, RF/IF, modem, vocoder, forward error correction codec, amplitude-companded single sideband, and input/output modules, as well as the flexible interface. Designs for a three-carrier base station and a 10-carrier gateway station are also discussed, including the interface with the controllers and with the public-switched telephone networks at the gateway station. Functional specifications are given for the transceiver, the base station, and the gateway station.

Integration of a satellite ground support system based on analysis of the satellite ground support domain

Science.gov (United States)

Pendley, R. D.; Scheidker, E. J.; Levitt, D. S.; Myers, C. R.; Werking, R. D.

1994-11-01

This analysis defines a complete set of ground support functions based on those practiced in real space flight operations during the on-orbit phase of a mission. These functions are mapped against ground support functions currently in use by NASA and DOD. Software components to provide these functions can be hosted on RISC-based work stations and integrated to provide a modular, integrated ground support system. Such modular systems can be configured to provide as much ground support functionality as desired. This approach to ground systems has been widely proposed and prototyped both by government institutions and commercial vendors. The combined set of ground support functions we describe can be used as a standard to evaluate candidate ground systems. This approach has also been used to develop a prototype of a modular, loosely-integrated ground support system, which is discussed briefly. A crucial benefit to a potential user is that all the components are flight-qualified, thus giving high confidence in their accuracy and reliability.

Ground-Fault Characteristic Analysis of Grid-Connected Photovoltaic Stations with Neutral Grounding Resistance

Directory of Open Access Journals (Sweden)

Zheng Li

2017-11-01

Full Text Available A centralized grid-connected photovoltaic (PV station is a widely adopted method of neutral grounding using resistance, which can potentially make pre-existing protection systems invalid and threaten the safety of power grids. Therefore, studying the fault characteristics of grid-connected PV systems and their impact on power-grid protection is of great importance. Based on an analysis of the grid structure of a grid-connected PV system and of the low-voltage ride-through control characteristics of a photovoltaic power supply, this paper proposes a short-circuit calculation model and a fault-calculation method for this kind of system. With respect to the change of system parameters, particularly the resistance connected to the neutral point, and the possible impact on protective actions, this paper achieves the general rule of short-circuit current characteristics through a simulation, which provides a reference for devising protection configurations.

The Rover Environmental Monitoring Station Ground Temperature Sensor: A Pyrometer for Measuring Ground Temperature on Mars

Directory of Open Access Journals (Sweden)

Miguel Ramos

2010-10-01

Full Text Available We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS Ground Temperature Sensor (GTS, an instrument aboard NASA’s Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor’s main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight calibration system that permits sensor recalibration when sensor sensitivity has been degraded by deposition of dust over the optics. This paper provides the first results of a GTS engineering model working in a Martian-like, extreme environment.

The application of GPS time information in the telemetry ground station

International Nuclear Information System (INIS)

Zhang Songtao; Zhang Yusong; Sun Xiurui

2001-01-01

GPS time information is a kind of practicable information resource that can be shared all over the world. Now it is the most accurate wireless time information. The major of this paper is the application information of GPS time information in telemetry. The main point introduces how to make use of the GPS time information to produce GPS-IRIG-B time code for proving ground and how to send time information to related equipment in telemetry ground station

Airline Operational Control (AOC)/UAS Ground Control Station (GCS) Collaboration, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose to form a network and a set of tools that will create a shared situation awareness with Unmanned Aircraft Systems (UAS) Ground Control Stations (GCSs) and...

Space and Ground-Based Infrastructures

Science.gov (United States)

Weems, Jon; Zell, Martin

This chapter deals first with the main characteristics of the space environment, outside and inside a spacecraft. Then the space and space-related (ground-based) infrastructures are described. The most important infrastructure is the International Space Station, which holds many European facilities (for instance the European Columbus Laboratory). Some of them, such as the Columbus External Payload Facility, are located outside the ISS to benefit from external space conditions. There is only one other example of orbital platforms, the Russian Foton/Bion Recoverable Orbital Capsule. In contrast, non-orbital weightless research platforms, although limited in experimental time, are more numerous: sounding rockets, parabolic flight aircraft, drop towers and high-altitude balloons. In addition to these facilities, there are a number of ground-based facilities and space simulators, for both life sciences (for instance: bed rest, clinostats) and physical sciences (for instance: magnetic compensation of gravity). Hypergravity can also be provided by human and non-human centrifuges.

Low-cost approach for a software-defined radio based ground station receiver for CCSDS standard compliant S-band satellite communications

Science.gov (United States)

Boettcher, M. A.; Butt, B. M.; Klinkner, S.

2016-10-01

A major concern of a university satellite mission is to download the payload and the telemetry data from a satellite. While the ground station antennas are in general easy and with limited afford to procure, the receiving unit is most certainly not. The flexible and low-cost software-defined radio (SDR) transceiver "BladeRF" is used to receive the QPSK modulated and CCSDS compliant coded data of a satellite in the HAM radio S-band. The control software is based on the Open Source program GNU Radio, which also is used to perform CCSDS post processing of the binary bit stream. The test results show a good performance of the receiving system.

A Technical Approach to the Evaluation of Radiofrequency Radiation Emissions from Mobile Telephony Base Stations

Directory of Open Access Journals (Sweden)

Raimondas Buckus

2017-03-01

Full Text Available During the last two decades, the number of macrocell mobile telephony base station antennas emitting radiofrequency (RF electromagnetic radiation (EMR in residential areas has increased significantly, and therefore much more attention is being paid to RF EMR and its effects on human health. Scientific field measurements of public exposure to RF EMR (specifically to radio frequency radiation from macrocell mobile telephony base station antennas and RF electromagnetic field (EMF intensity parameters in the environment are discussed in this article. The research methodology is applied according to the requirements of safety norms and Lithuanian Standards in English (LST EN. The article presents and analyses RF EMFs generated by mobile telephony base station antennas in areas accessible to the general public. Measurements of the RF electric field strength and RF EMF power density were conducted in the near- and far-fields of the mobile telephony base station antenna. Broadband and frequency-selective measurements were performed outside (on the roof and on the ground and in a residential area. The tests performed on the roof in front of the mobile telephony base station antennas in the near-field revealed the presence of a dynamic energy interaction within the antenna electric field, which changes rapidly with distance. The RF EMF power density values on the ground at distances of 50, 100, 200, 300, 400, and 500 m from the base station are very low and are scattered within intervals of 0.002 to 0.05 μW/cm2. The results were compared with international exposure guidelines (ICNIRP.

A Technical Approach to the Evaluation of Radiofrequency Radiation Emissions from Mobile Telephony Base Stations.

Science.gov (United States)

Buckus, Raimondas; Strukčinskienė, Birute; Raistenskis, Juozas; Stukas, Rimantas; Šidlauskienė, Aurelija; Čerkauskienė, Rimantė; Isopescu, Dorina Nicolina; Stabryla, Jan; Cretescu, Igor

2017-03-01

During the last two decades, the number of macrocell mobile telephony base station antennas emitting radiofrequency (RF) electromagnetic radiation (EMR) in residential areas has increased significantly, and therefore much more attention is being paid to RF EMR and its effects on human health. Scientific field measurements of public exposure to RF EMR (specifically to radio frequency radiation) from macrocell mobile telephony base station antennas and RF electromagnetic field (EMF) intensity parameters in the environment are discussed in this article. The research methodology is applied according to the requirements of safety norms and Lithuanian Standards in English (LST EN). The article presents and analyses RF EMFs generated by mobile telephony base station antennas in areas accessible to the general public. Measurements of the RF electric field strength and RF EMF power density were conducted in the near- and far-fields of the mobile telephony base station antenna. Broadband and frequency-selective measurements were performed outside (on the roof and on the ground) and in a residential area. The tests performed on the roof in front of the mobile telephony base station antennas in the near-field revealed the presence of a dynamic energy interaction within the antenna electric field, which changes rapidly with distance. The RF EMF power density values on the ground at distances of 50, 100, 200, 300, 400, and 500 m from the base station are very low and are scattered within intervals of 0.002 to 0.05 μW/cm². The results were compared with international exposure guidelines (ICNIRP).

Preliminary PANSAT ground station software design and use of an expert system to analyze telemetry

Science.gov (United States)

Lawrence, Gregory W.

1994-03-01

The Petite Amateur Navy Satellite (PANSAT) is a communications satellite designed to be used by civilian amateur radio operators. A master ground station is being built at the Naval Postgraduate School. This computer system performs satellite commands, displays telemetry, trouble-shoots problems, and passes messages. The system also controls an open loop tracking antenna. This paper concentrates on the telemetry display, decoding, and interpretation through artificial intelligence (AI). The telemetry is displayed in an easily interpretable format, so that any user can understand the current health of the satellite and be cued as to any problems and possible solutions. Only the master ground station has the ability to receive all telemetry and send commands to the spacecraft; civilian ham users do not have access to this information. The telemetry data is decommutated and analyzed before it is displayed to the user, so that the raw data will not have to be interpreted by ground users. The analysis will use CLIPS imbedded in the code, and derive its inputs from telemetry decommutation. The program is an expert system using a forward chaining set of rules based on the expected operation and parameters of the satellite. By building the rules during the construction and design of the satellite, the telemetry can be well understood and interpreted after the satellite is launched and the designers may no longer be available to provide input to the problem.

Easy-to-Use UAV Ground Station Software for Low-Altitude Civil Operations, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose to design and develop easy-to-use Ground Control Station (GCS) software for low-altitude civil Unmanned Aerial Vehicle (UAV) operations. The GCS software...

Secure base stations

NARCIS (Netherlands)

Bosch, Peter; Brusilovsky, Alec; McLellan, Rae; Mullender, Sape J.; Polakos, Paul

2009-01-01

With the introduction of the third generation (3G) Universal Mobile Telecommunications System (UMTS) base station router (BSR) and fourth generation (4G) base stations, such as the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) Evolved Node B (eNB), it has become important to

Development of a PC-based ground support system for a small satellite instrument

Science.gov (United States)

Deschambault, Robert L.; Gregory, Philip R.; Spenler, Stephen; Whalen, Brian A.

1993-11-01

The importance of effective ground support for the remote control and data retrieval of a satellite instrument cannot be understated. Problems with ground support may include the need to base personnel at a ground tracking station for extended periods, and the delay between the instrument observation and the processing of the data by the science team. Flexible solutions to such problems in the case of small satellite systems are provided by using low-cost, powerful personal computers and off-the-shelf software for data acquisition and processing, and by using Internet as a communication pathway to enable scientists to view and manipulate satellite data in real time at any ground location. The personal computer based ground support system is illustrated for the case of the cold plasma analyzer flown on the Freja satellite. Commercial software was used as building blocks for writing the ground support equipment software. Several levels of hardware support, including unit tests and development, functional tests, and integration were provided by portable and desktop personal computers. Satellite stations in Saskatchewan and Sweden were linked to the science team via phone lines and Internet, which provided remote control through a central point. These successful strategies will be used on future small satellite space programs.

Ground receiving station (GRS) of UMS - receiving and processing the electromagnetic wave data from satellite

International Nuclear Information System (INIS)

Mohammad Syahmi Nordin; Fauziah Abdul Aziz

2007-01-01

The low resolution Automatic Picture Transmission (APT) data from the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites Advanced Very High Resolution Radiometer (AVHRR) is being received and recorded in real-time mode at ground receiving station in School of Science and Technology, Universiti Malaysia Sabah. The system is suitable for the developing and undeveloped countries in south and Southeast Asia and is said to be acceptable for engineering, agricultural, climatological and environmental applications. The system comprises a personal computer attached with a small APT receiver. The data transmission between the ground receiving station and NOAA satellites is using the electromagnetic wave. The relation for receiving and processing the electromagnetic wave in the transmission will be discussed. (Author)

Measurements of Electromagnetic Fields Emitted from Cellular Base Stations in

Directory of Open Access Journals (Sweden)

K. J. Ali

2013-05-01

Full Text Available With increasing the usage of mobile communication devices and internet network information, the entry of private telecommunications companies in Iraq has been started since 2003. These companies began to build up cellular towers to accomplish the telecommunication works but they ignore the safety conditions imposed for the health and environment that are considered in random way. These negative health effects which may cause a health risk for life beings and environment pollution. The aim of this work is to determine the safe and unsafe ranges and discuss damage caused by radiation emitted from Asia cell base stations in Shirqat city and discuses the best ways in which can be minimize its exposure level to avoid its negative health effects. Practical measurements of power density around base stations has been accomplished by using a radiation survey meter type (Radio frequency EMF Strength Meter 480846 in two ways. The first way of measurements has been accomplished at a height of 2 meters above ground for different distances from (0-300 meters .The second way is at a distance of 150 meters for different levels from (2-15 meters above ground level. The maximum measured power density is about (3 mW/m2. Results indicate that the levels of power density are far below the RF radiation exposure of USSR safety standards levels. And that means these cellular base station don't cause negative the health effect for life being if the exposure is within the acceptable international standard levels.

Satellite and ground-based sensors for the Urban Heat Island analysis in the city of Rome

DEFF Research Database (Denmark)

Fabrizi, Roberto; Bonafoni, Stefania; Biondi, Riccardo

2010-01-01

In this work, the trend of the Urban Heat Island (UHI) of Rome is analyzed by both ground-based weather stations and a satellite-based infrared sensor. First, we have developed a suitable algorithm employing satellite brightness temperatures for the estimation of the air temperature belonging...... and nighttime scenes taken between 2003 and 2006 have been processed. Analysis of the Canopy Layer Heat Island (CLHI) during summer months reveals a mean growth in magnitude of 3-4 K during nighttime and a negative or almost zero CLHI intensity during daytime, confirmed by the weather stations. © 2010...... by the authors; licensee MDPI, Basel, Switzerland. Keyword: Thermal pollution,Summer months,Advanced-along track scanning radiometers,Urban heat island,Remote sensing,Canopy layer,Atmospheric temperature,Ground based sensors,Weather information services,Satellite remote sensing,Infra-red sensor,Weather stations...

Ground-water hydrology and simulation of ground-water flow at Operable Unit 3 and surrounding region, U.S. Naval Air Station, Jacksonville, Florida

Science.gov (United States)

Davis, J.H.

1998-01-01

The Naval Air Station, Jacksonville (herein referred to as the Station), occupies 3,800 acres adjacent to the St. Johns River in Duval County, Florida. Operable Unit 3 (OU3) occupies 134 acres on the eastern side of the Station and has been used for industrial and commercial purposes since World War II. Ground water contaminated by chlorinated organic compounds has been detected in the surficial aquifer at OU3. The U.S. Navy and U.S. Geological Survey (USGS) conducted a cooperative hydrologic study to evaluate the potential for ground water discharge to the neighboring St. Johns River. A ground-water flow model, previously developed for the area, was recalibrated for use in this study. At the Station, the surficial aquifer is exposed at land surface and forms the uppermost permeable unit. The aquifer ranges in thickness from 30 to 100 feet and consists of unconsolidated silty sands interbedded with local beds of clay. The low-permeability clays of the Hawthorn Group form the base of the aquifer. The USGS previously conducted a ground-water investigation at the Station that included the development and calibration of a 1-layer regional ground-water flow model. For this investigation, the regional model was recalibrated using additional data collected after the original calibration. The recalibrated model was then used to establish the boundaries for a smaller subregional model roughly centered on OU3. Within the subregional model, the surficial aquifer is composed of distinct upper and intermediate layers. The upper layer extends from land surface to a depth of approximately 15 feet below sea level; the intermediate layer extends from the upper layer down to the top of the Hawthorn Group. In the northern and central parts of OU3, the upper and intermediate layers are separated by a low-permeability clay layer. Horizontal hydraulic conductivities in the upper layer, determined from aquifer tests, range from 0.19 to 3.8 feet per day. The horizontal hydraulic

Base Station Performance Model

OpenAIRE

Walsh, Barbara; Farrell, Ronan

2005-01-01

At present the testing of power amplifiers within base station transmitters is limited to testing at component level as opposed to testing at the system level. While the detection of catastrophic failure is possible, that of performance degradation is not. This paper proposes a base station model with respect to transmitter output power with the aim of introducing system level monitoring of the power amplifier behaviour within the base station. Our model reflects the expe...

Retrievals of formaldehyde from ground-based FTIR and MAX-DOAS observations at the Jungfraujoch station and comparisons with GEOS-Chem and IMAGES model simulations

Directory of Open Access Journals (Sweden)

B. Franco

2015-04-01

Full Text Available As an ubiquitous product of the oxidation of many volatile organic compounds (VOCs, formaldehyde (HCHO plays a key role as a short-lived and reactive intermediate in the atmospheric photo-oxidation pathways leading to the formation of tropospheric ozone and secondary organic aerosols. In this study, HCHO profiles have been successfully retrieved from ground-based Fourier transform infrared (FTIR solar spectra and UV-visible Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS scans recorded during the July 2010–December 2012 time period at the Jungfraujoch station (Swiss Alps, 46.5° N, 8.0° E, 3580 m a.s.l.. Analysis of the retrieved products has revealed different vertical sensitivity between both remote sensing techniques. Furthermore, HCHO amounts simulated by two state-of-the-art chemical transport models (CTMs, GEOS-Chem and IMAGES v2, have been compared to FTIR total columns and MAX-DOAS 3.6–8 km partial columns, accounting for the respective vertical resolution of each ground-based instrument. Using the CTM outputs as the intermediate, FTIR and MAX-DOAS retrievals have shown consistent seasonal modulations of HCHO throughout the investigated period, characterized by summertime maximum and wintertime minimum. Such comparisons have also highlighted that FTIR and MAX-DOAS provide complementary products for the HCHO retrieval above the Jungfraujoch station. Finally, tests have revealed that the updated IR parameters from the HITRAN 2012 database have a cumulative effect and significantly decrease the retrieved HCHO columns with respect to the use of the HITRAN 2008 compilation.

Elimination of Coptotermes lacteus (Froggatt) (Blattodea: Rhinotemitidae) Colonies Using Bistrifluron Bait Applied through In-Ground Bait Stations Surrounding Mounds.

Science.gov (United States)

Webb, Garry

2017-09-12

The efficacy of bistrifluron termite bait was evaluated using in-ground bait stations placed around Coptotermes lacteus mounds in south-eastern Australia during late summer and autumn (late February to late May 2012). Four in-ground bait stations containing timber billets were placed around each of twenty mounds. Once sufficient numbers of in-ground stations were infested by termites, mounds were assigned to one of four groups (one, two, three or four 120 g bait canisters or 120 to 480 g bait in total per mound) and bait canisters installed. One mound, nominally assigned treatment with two canisters ultimately had no termite interception in any of the four in-ground stations and not treated. Eighteen of the remaining 19 colonies were eliminated by 12 weeks after bait placement, irrespective of bait quantity removed (range 43 to 480 g). Measures of colony decline-mound repair capability and internal core temperature-did not accurately reflect the colony decline, as untreated colonies showed a similar pattern of decline in both repair capability and internal mound core temperature. However, during the ensuing spring-summer period, capacity to repair the mound was restored in untreated colonies and the internal core temperature profile was similar to the previous spring-summer period which indicated that these untreated colonies remained healthy.

Improving the Quality of Satellite Imagery Based on Ground-Truth Data from Rain Gauge Stations

Directory of Open Access Journals (Sweden)

Ana F. Militino

2018-03-01

Full Text Available Multitemporal imagery is by and large geometrically and radiometrically accurate, but the residual noise arising from removal clouds and other atmospheric and electronic effects can produce outliers that must be mitigated to properly exploit the remote sensing information. In this study, we show how ground-truth data from rain gauge stations can improve the quality of satellite imagery. To this end, a simulation study is conducted wherein different sizes of outlier outbreaks are spread and randomly introduced in the normalized difference vegetation index (NDVI and the day and night land surface temperature (LST of composite images from Navarre (Spain between 2011 and 2015. To remove outliers, a new method called thin-plate splines with covariates (TpsWc is proposed. This method consists of smoothing the median anomalies with a thin-plate spline model, whereby transformed ground-truth data are the external covariates of the model. The performance of the proposed method is measured with the square root of the mean square error (RMSE, calculated as the root of the pixel-by-pixel mean square differences between the original data and the predicted data with the TpsWc model and with a state-space model with and without covariates. The study shows that the use of ground-truth data reduces the RMSE in both the TpsWc model and the state-space model used for comparison purposes. The new method successfully removes the abnormal data while preserving the phenology of the raw data. The RMSE reduction percentage varies according to the derived variables (NDVI or LST, but reductions of up to 20% are achieved with the new proposal.

Cost and Performance Comparison of an Earth-Orbiting Optical Communication Relay Transceiver and a Ground-Based Optical Receiver Subnet

Science.gov (United States)

Wilson, K. E.; Wright, M.; Cesarone, R.; Ceniceros, J.; Shea, K.

2003-01-01

Optical communications can provide high-data-rate telemetry from deep-space probes with subsystems that have lower mass, consume less power, and are smaller than their radio frequency (RF) counterparts. However, because optical communication is more affected by weather than is RF communication, it requires ground station site diversity to mitigate the adverse effects of inclement weather on the link. An optical relay satellite is not affected by weather and can provide 24-hour coverage of deep-space probes. Using such a relay satellite for the deep-space link and an 8.4-GHz (X-band) link to a ground station would support high-data-rate links from small deep-space probes with very little link loss due to inclement weather. We have reviewed past JPL-funded work on RF and optical relay satellites, and on proposed clustered and linearly dispersed optical subnets. Cost comparisons show that the life cycle costs of a 7-m optical relay station based on the heritage of the Next Generation Space Telescope is comparable to that of an 8-station subnet of 10-m optical ground stations. This makes the relay link an attractive option vis-a-vis a ground station network.

A New Technique to Observe ENSO Activity via Ground-Based GPS Receivers

Science.gov (United States)

Suparta, Wayan; Iskandar, Ahmad; Singh, Mandeep Singh Jit

In an attempt to study the effects of global climate change in the tropics for improving global climate model, this paper aims to detect the ENSO events, especially El Nino phase by using ground-based GPS receivers. Precipitable water vapor (PWV) obtained from the Global Positioning System (GPS) Meteorology measurements in line with the sea surface temperature anomaly (SSTa) are used to connect their response to El Niño activity. The data gathered from four selected stations over the Southeast Asia, namely PIMO (Philippines), KUAL (Malaysia), NTUS (Singapore) and BAKO (Indonesia) for the year of 2009/2010 were processed. A strong correlation was observed for PIMO station with a correlation coefficient of -0.90, significantly at the 99 % confidence level. In general, the relationship between GPS PWV and SSTa at all stations on a weekly basis showed with a negative correlation. The negative correlation indicates that during the El Niño event, the PWV variation was in decreased trend. Decreased trend of PWV value is caused by a dry season that affected the GPS signals in the ocean-atmospheric coupling. Based on these promising results, we can propose that the ground-based GPS receiver is capable used to monitor ENSO activity and this is a new prospective method that previously unexplored.

Validation of GOME (ERS-2) NO2 vertical column data with ground-based measurements at Issyk-Kul (Kyrgyzstan)

Science.gov (United States)

Ionov, D.; Sinyakov, V.; Semenov, V.

Starting from 1995 the global monitoring of atmospheric nitrogen dioxide is carried out by the measurements of nadir-viewing GOME spectrometer aboard ERS-2 satellite. Continuous validation of that data by means of comparisons with well-controlled ground-based measurements is important to ensure the quality of GOME data products and improve related retrieval algorithms. At the station of Issyk-Kul (Kyrgyzstan) the ground-based spectroscopic observations of NO2 vertical column have been started since 1983. The station is located on the northern shore of Issyk-Kul lake, 1650 meters above the sea level (42.6 N, 77.0 E). The site is equipped with grating spectrometer for the twilight measurements of zenith-scattered solar radiation in the visible range, and applies the DOAS technique to retrieve NO2 vertical column. It is included in the list of NDSC stations as a complementary one. The present study is focused on validation of GOME NO2 vertical column data, based on 8-year comparison with correlative ground-based measurements at Issyk-Kul station in 1996-2003. Within the investigation, an agreement of both individual and monthly averaged GOME measurements with corresponding twilight ground-based observations is examined. Such agreement is analyzed with respect to different conditions (season, sun elevation), temporal/spatial criteria choice (actual overpass location, correction for diurnal variation) and data processing (GDP version 2.7, 3.0). In addition, NO2 vertical columns were integrated from simultaneous stratospheric profile measurements by NASA HALOE and SAGE-II/III satellite instruments and introduced to explain the differences with ground-based observations. In particular cases, NO2 vertical profiles retrieved from the twilight ground-based measurements at Issuk-Kul were also included into comparison. Overall, summertime GOME NO2 vertical columns were found to be systematicaly lower than ground-based data. This work was supported by International Association

Study on Vibration Reduction Method for a Subway Station in Soft Ground

Directory of Open Access Journals (Sweden)

Xian-Feng Ma

2017-01-01

Full Text Available With the rapid development of metro system in urban areas, vibration and its impact on adjacent structures caused by metro operation have drawn much attention of researches and worries relating to it have risen. This paper analyzed the vibration attenuation and the environment impact by a case study of a subway station in soft ground with adjacent laboratory building. A method of setting a compound separation barrier surrounding the station is checked and different materials used in the barrier have been tried and tested through numerical analysis. Key parameters of the material and the effects of vibration reduction are studied with the purpose that similar methodology and findings can be referenced in future practices.

Communication grounding facility

International Nuclear Information System (INIS)

Lee, Gye Seong

1998-06-01

It is about communication grounding facility, which is made up twelve chapters. It includes general grounding with purpose, materials thermal insulating material, construction of grounding, super strength grounding method, grounding facility with grounding way and building of insulating, switched grounding with No. 1A and LCR, grounding facility of transmission line, wireless facility grounding, grounding facility in wireless base station, grounding of power facility, grounding low-tenton interior power wire, communication facility of railroad, install of arrester in apartment and house, install of arrester on introduction and earth conductivity and measurement with introduction and grounding resistance.

[Level of microwave radiation from mobile phone base stations built in residential districts].

Science.gov (United States)

Hu, Ji; Lu, Yiyang; Zhang, Huacheng; Xie, Hebing; Yang, Xinwen

2009-11-01

To investigate the condition of microwave radiation pollution from mobile phone base station built in populated area. Random selected 18 residential districts where had base station and 10 residential districts where had no base stations. A TES-92 electromagnetic radiation monitor were used to measure the intensity of microwave radiation in external and internal living environment. The intensities of microwave radiation in the exposure residential districts were more higher than those of the control residential districts (p station, it would gradually weaken with the increase of the distance. The level of microwave radiation in antenna main lobe region is not certainly more higher than the side lobe direction, and the side lobe direction also is not more lower. At the same district, where there were two base stations, the electromagnetic field nestification would take place in someplace. The intensities of microwave radiation outside the exposure windows in the resident room not only changed with distance but also with the height of the floor. The intensities of microwave radiation inside the aluminum alloys security net were more lower than those of outside the aluminum alloys security net (p 0.05). Although all the measure dates on the ground around the base station could be below the primary standard in "environment electromagnetic wave hygienic standard" (GB9175-88), there were still a minorities of windows which exposed to the base station were higher, and the outside or inside of a few window was even higher beyond the primary safe level defined standard. The aluminum alloys security net can partly shield the microwave radiation from the mobile phone base station.

Elimination of Coptotermes lacteus (Froggatt (Blattodea: Rhinotemitidae Colonies Using Bistrifluron Bait Applied through In-Ground Bait Stations Surrounding Mounds

Directory of Open Access Journals (Sweden)

Garry Webb

2017-09-01

Full Text Available The efficacy of bistrifluron termite bait was evaluated using in-ground bait stations placed around Coptotermes lacteus mounds in south-eastern Australia during late summer and autumn (late February to late May 2012. Four in-ground bait stations containing timber billets were placed around each of twenty mounds. Once sufficient numbers of in-ground stations were infested by termites, mounds were assigned to one of four groups (one, two, three or four 120 g bait canisters or 120 to 480 g bait in total per mound and bait canisters installed. One mound, nominally assigned treatment with two canisters ultimately had no termite interception in any of the four in-ground stations and not treated. Eighteen of the remaining 19 colonies were eliminated by 12 weeks after bait placement, irrespective of bait quantity removed (range 43 to 480 g. Measures of colony decline—mound repair capability and internal core temperature—did not accurately reflect the colony decline, as untreated colonies showed a similar pattern of decline in both repair capability and internal mound core temperature. However, during the ensuing spring–summer period, capacity to repair the mound was restored in untreated colonies and the internal core temperature profile was similar to the previous spring–summer period which indicated that these untreated colonies remained healthy.

Evaluation of tropospheric and stratospheric ozone trends over Western Europe from ground-based FTIR network observations

Directory of Open Access Journals (Sweden)

C. Vigouroux

2008-12-01

Full Text Available Within the European project UFTIR (Time series of Upper Free Troposphere observations from an European ground-based FTIR network, six ground-based stations in Western Europe, from 79° N to 28° N, all equipped with Fourier Transform infrared (FTIR instruments and part of the Network for the Detection of Atmospheric Composition Change (NDACC, have joined their efforts to evaluate the trends of several direct and indirect greenhouse gases over the period 1995–2004. The retrievals of CO, CH₄, C₂H₆, N₂O, CHClF₂, and O₃ have been optimized. Using the optimal estimation method, some vertical information can be obtained in addition to total column amounts. A bootstrap resampling method has been implemented to determine annual partial and total column trends for the target gases. The present work focuses on the ozone results. The retrieved time series of partial and total ozone columns are validated with ground-based correlative data (Brewer, Dobson, UV-Vis, ozonesondes, and Lidar. The observed total column ozone trends are in agreement with previous studies: 1 no total column ozone trend is seen at the lowest latitude station Izaña (28° N; 2 slightly positive total column trends are seen at the two mid-latitude stations Zugspitze and Jungfraujoch (47° N, only one of them being significant; 3 the highest latitude stations Harestua (60° N, Kiruna (68° N and Ny-Ålesund (79° N show significant positive total column trends. Following the vertical information contained in the ozone FTIR retrievals, we provide partial columns trends for the layers: ground-10 km, 10–18 km, 18–27 km, and 27–42 km, which helps to distinguish the contributions from dynamical and chemical changes on the total column ozone trends. We obtain no statistically significant trends in the ground-10 km layer for five out of the six ground-based stations. We find significant positive trends for the lowermost

Communication Base Station Log Analysis Based on Hierarchical Clustering

Directory of Open Access Journals (Sweden)

Zhang Shao-Hua

2017-01-01

Full Text Available Communication base stations generate massive data every day, these base station logs play an important value in mining of the business circles. This paper use data mining technology and hierarchical clustering algorithm to group the scope of business circle for the base station by recording the data of these base stations.Through analyzing the data of different business circle based on feature extraction and comparing different business circle category characteristics, which can choose a suitable area for operators of commercial marketing.

Lightning current distribution to ground at a power line tower carrying a radio base station

NARCIS (Netherlands)

Grcev, L.; Deursen, van A.P.J.; Waes, van J.B.M.

2005-01-01

Radio base stations are often mounted on towers of power transmission lines. They are usually powered from the low-voltage network through an isolating transformer, to separate the high- and low-voltage networks. The isolating transformer ensures security at customers' premises in the case of nearby

Assessment of infrasound signals recorded on seismic stations and infrasound arrays in the western United States using ground truth sources

Science.gov (United States)

Park, Junghyun; Hayward, Chris; Stump, Brian W.

2018-06-01

Ground truth sources in Utah during 2003-2013 are used to assess the contribution of temporal atmospheric conditions to infrasound detection and the predictive capabilities of atmospheric models. Ground truth sources consist of 28 long duration static rocket motor burn tests and 28 impulsive rocket body demolitions. Automated infrasound detections from a hybrid of regional seismometers and infrasound arrays use a combination of short-term time average/long-term time average ratios and spectral analyses. These detections are grouped into station triads using a Delaunay triangulation network and then associated to estimate phase velocity and azimuth to filter signals associated with a particular source location. The resulting range and azimuth distribution from sources to detecting stations varies seasonally and is consistent with predictions based on seasonal atmospheric models. Impulsive signals from rocket body detonations are observed at greater distances (>700 km) than the extended duration signals generated by the rocket burn test (up to 600 km). Infrasound energy attenuation associated with the two source types is quantified as a function of range and azimuth from infrasound amplitude measurements. Ray-tracing results using Ground-to-Space atmospheric specifications are compared to these observations and illustrate the degree to which the time variations in characteristics of the observations can be predicted over a multiple year time period.

Multiple ground-based and satellite observations of global Pi 2 magnetic pulsations

International Nuclear Information System (INIS)

Yumoto, K.; Takahashi, K.; Sakurai, T.; Sutcliffe, P.R.; Kokubun, S.; Luehr, H.; Saito, T.; Kuwashima, M.; Sato, N.

1990-01-01

Four Pi 2 magnetic pulsations, observed on the ground at L = 1.2-6.9 in the interval from 2,300 UT on May 22 to 0300 UT on May 23, 1985, provide new evidence of a global nature of Pi 2 pulsations in the inner (L approx-lt 7) region of the magnetosphere bounded by the plasma sheet during quiet geomagnetic conditions. In the present study, magnetic data have been collected from stations distributed widely both in local time and in latitude, including conjugate stations, and from the AMPTE/CCE spacecraft located in the magnetotail. On the basis of high time resolution magnetic field data, the following characteristics of Pi 2 have been established: horizontal components, H and D, of the Pi 2 oscillate nearly antiphase and in-phase, respectively, between the high- and low-altitude stations in the midnight southern hemisphere. Both the H and D components of the Pi 2 have nearly in-phase relationships between the nightside and the dayside stations at low latitude. The Pi 2 amplitude is larger at the high-latitude station and decreases toward lower latitudes. The dominant periods of the Pi 2 are nearly identical at all stations. Although a direct coincidence between spacecraft-observed and ground-based global Pi 2 events does not exist for these events, the Pi 2 events are believed to be a forced field line oscillation of global scale, coupled with the magnetospheric cavity resonance wave in the inner magnetosphere during the substorm expansive phase

47 CFR 95.139 - Adding a small base station or a small control station.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Adding a small base station or a small control... base station or a small control station. (a) Except for a GMRS system licensed to a non-individual, one or more small base stations or a small control station may be added to a GMRS system at any point...

Frequency domain analysis of the lightning current distribution to ground at the transmission line tower with cellular phone base station

NARCIS (Netherlands)

Grcev, L.; Deursen, van A.P.J.; Waes, van J.B.M.

2003-01-01

Cellular phone base stations are often placed in the poles of power transmission lines. We consider the case when such base stations are powered from the low-voltage network. Of special concern is the current that might be led through the cable metallic shields to other customers' premises in case

Development of a Ground Test Concept Based on Multi-Rotors for In-Flight RVD Experimentation

Science.gov (United States)

2015-08-01

Linux Real-Time work station • Ad-Hoc WiFi internal network for data streaming • High pressure air compressor and compressed air filling station. 12... Air Force Research Laboratory Air Force Office of Scientific Research European Office of Aerospace Research and Development Unit 4515, APO...of screws and nuts, • the same rod is connected to a structure with a base on ground. 6 Distribution A: Approved for public release; distribution is

Observation of an Aligned Gas - Solid "Eutectic" during Controlled Directional Solidification Aboard the International Space Station - Comparison with Ground-based Studies

Science.gov (United States)

Grugel, R. N.; Anilkumar, A.

2005-01-01

Direct observation of the controlled melting and solidification of succinonitrile was conducted in the glovebox facility of the International Space Station (ISS). The experimental samples were prepared on ground by filling glass tubes, 1 cm ID and approximately 30 cm in length, with pure succinonitrile (SCN) in an atmosphere of nitrogen at 450 millibar pressure for eventual processing in the Pore Formation and Mobility Investigation (PFMI) apparatus in the glovebox facility (GBX) on board the ISS. Real time visualization during controlled directional melt back of the sample showed nitrogen bubbles emerging from the interface and moving through the liquid up the imposed temperature gradient. Over a period of time these bubbles disappear by dissolving into the melt. Translation is stopped after melting back of about 9 cm of the sample, with an equilibrium solid-liquid interface established. During controlled re-solidification, aligned tubes of gas were seen growing perpendicular to the planar solid/liquid interface, inferring that the nitrogen previously dissolved into the liquid SCN was now coming out at the solid/liquid interface and forming the little studied liquid = solid + gas eutectic-type reaction. The observed structure is evaluated in terms of spacing dimensions, interface undercooling, and mechanisms for spacing adjustments. Finally, the significance of processing in a microgravity environment is ascertained in view of ground-based results.

Space debris removal using a high-power ground-based laser

Energy Technology Data Exchange (ETDEWEB)

Monroe, D.K.

1993-12-31

The feasibility and practicality of using a ground-based laser (GBL) to remove artificial space debris is examined. Physical constraints indicate that a reactor-pumped laser (RPL) may be best suited for this mission, because of its capabilities for multimegawatt output long run-times, and near-diffraction-limited initial beams. Simulations of a laser-powered debris removal system indicate that a 5-MW RPL with a 10-meter-diameter beam director and adaptive optics capabilities can deorbit 1-kg debris from space station altitudes. Larger debris can be deorbited or transferred to safer orbits after multiple laser engagements. A ground-based laser system may be the only realistic way to access and remove some 10,000 separate objects, having velocities in the neighborhood of 7 km/sec, and being spatially distributed over some 10{sup 10} km{sup 3} of space.

The ground based plan

International Nuclear Information System (INIS)

1989-01-01

The paper presents a report of ''The Ground Based Plan'' of the United Kingdom Science and Engineering Research Council. The ground based plan is a plan for research in astronomy and planetary science by ground based techniques. The contents of the report contains a description of:- the scientific objectives and technical requirements (the basis for the Plan), the present organisation and funding for the ground based programme, the Plan, the main scientific features and the further objectives of the Plan. (U.K.)

The SPQR experiment: detecting damage to orbiting spacecraft with ground-based telescopes

Science.gov (United States)

Paolozzi, Antonio; Porfilio, Manfredi; Currie, Douglas G.; Dantowitz, Ronald F.

2007-09-01

The objective of the Specular Point-like Quick Reference (SPQR) experiment was to evaluate the possibility of improving the resolution of ground-based telescopic imaging of manned spacecraft in orbit. The concept was to reduce image distortions due to atmospheric turbulence by evaluating the Point Spread Function (PSF) of a point-like light reference and processing the spacecraft image accordingly. The target spacecraft was the International Space Station (ISS) and the point-like reference was provided by a laser beam emitted by the ground station and reflected back to the telescope by a Cube Corner Reflector (CCR) mounted on an ISS window. The ultimate objective of the experiment was to demonstrate that it is possible to image spacecraft in Low Earth Orbit (LEO) with a resolution of 20 cm, which would have probably been sufficient to detect the damage which caused the Columbia disaster. The experiment was successfully performed from March to May 2005. The paper provides an overview of the SPQR experiment.

Hook whistlers observed at low latitude ground station Varanasi

International Nuclear Information System (INIS)

Khosa, P.N.; Lalmani; Ahmed, M.M.; Singh, B.D.

1983-01-01

Employing the Haselgrove ray tracing equations and a diffusive equilibrium model of the ionosphere, the propagation characteristics of hook whistlers recorded at low-latitude ground station Varanasi (geomag. lat., 16 0 6'N) are discussed. It is shown that the two traces of the hook whistlers are caused by the VLF waves radiated from the return stroke of a lightning discharge which after penetrating the ionosphere at two different entry points, propagated to the opposite hemisphere in the whistler mode and were received at 16 geomagnetic latitude. Further the crossing of ray paths for the same frequency leads to the explanation of the hook whistler. The lower and higher cut-off frequencies are explained in terms of their deviating away from the bunch of the recorded whistler waves and crossing of ray paths for the same frequency. (Auth.)

Nonstandard usage of ASS-500 station filters for determination of ground-level air contamination

International Nuclear Information System (INIS)

Kozak, K.; Jasinska, M.; Kwiatek, W.; Mietelski, J.W.; Dutkiewicz, E.

1998-01-01

The work describes nonstandard application of filters from ASS-500 station for the determination of the element content in the samples collected by PIXE method. Determination of gamma radioactive isotopes and alpha radioactive plutonium is also reviewed. Authors conclude that ASS-500 workstation allows collection of representative samples from the ground level air. These samples are suitable for the complex analysis of industrial pollution

Atmospheric methane variability at the Peterhof station (Russia): ground-based observations and modeling

Science.gov (United States)

Makarova, Maria; Kirner, Oliver; Poberovskii, Anatoliy; Imhasin, Humud; Timofeyev, Yuriy; Virolainen, Yana; Makarov, Boris

2014-05-01

MF from the true ones were detected for the Peterhof station (0.4% for TC and -0.2% for MF). It should be also noted that the limited number of sunny days may distort the annual cycle estimated from FTIR data (comparing to true). This fact have to take into account when mean levels of CH4 TC and MF obtained from FTIR compare against climatological or averaged model data. Ground-based in situ (local) observations of CH4 mole fraction (LMF) are being performed by LGR GGA-24r-EP gas analyzer since 2013 (at the Peterhof station). The monthly averaged amplitude of LMF diurnal cycle shows variations which are similar to the temporal behavior of MF CH4 retrieved from FTIR for 2013. It is suggested that the value of the amplitude of CH4 LMF diurnal variation characterizes the intensity of methane sources for the North-western region of Russia and can be used to explain the observed features of the annual variation of FTIR MF CH4. However, to prove this statement further simultaneous FTIR and in situ measurements of CH4 should be continued. Both, FTIR observations and EMAC simulations, revealed the positive trend of CH4 over 2009-2012 of about 0.2% per year (statistically significant). FTIR data for 2013 that were taken into account led to a decrease in trend value from 0.2%/yr (2009-2012) to 0.13%/yr (2009-2013). It may indicate the end of the period of extremely high growth rates of methane in the atmosphere that have been registered by different observational systems since 2006. Acknowledgements: This study was funded by Saint-Petersburg State University (grant No.11.0.44.2010), Russian Foundation for Basic Research (grants No.12-05-00596, 14-05-897). Measurement facilities were provided by Geo Environmental Research Center "Geomodel" of Saint-Petersburg State University.

VME-based remote instrument control without ground loops

CERN Document Server

Belleman, J; González, J L

1997-01-01

New electronics has been developed for the remote control of the pick-up electrodes at the CERN Proton Synchrotron (PS). Communication between VME-based control computers and remote equipment is via full duplex point-to-point digital data links. Data are sent and received in serial format over simple twisted pairs at a rate of 1 Mbit/s, for distances of up to 300 m. Coupling transformers are used to avoid ground loops. The link hardware consists of a general-purpose VME-module, the 'TRX' (transceiver), containing four FIFO-buffered communication channels, and a dedicated control card for each remote station. Remote transceiver electronics is simple enough not to require micro-controllers or processors. Currently, some sixty pick-up stations of various types, all over the PS Complex (accelerators and associated beam transfer lines) are equipped with the new system. Even though the TRX was designed primarily for communication with pick-up electronics, it could also be used for other purposes, for example to for...

Comparison of atmospheric CO2 mole fractions and source-sink characteristics at four WMO/GAW stations in China

Science.gov (United States)

Cheng, Siyang; Zhou, Lingxi; Tans, Pieter P.; An, Xingqin; Liu, Yunsong

2018-05-01

As CO2 is a primary driving factor of climate change, the mole fraction and source-sink characteristics of atmospheric CO2 over China are constantly inferred from multi-source and multi-site data. In this paper, we compared ground-based CO2 measurements with satellite retrievals and investigated the source-sink regional representativeness at China's four WMO/GAW stations. The results indicate that, firstly, atmospheric CO2 mole fractions from ground-based sampling measurement and Greenhouse Gases Observing Satellite (GOSAT) products reveal similar seasonal variation. The seasonal amplitude of the column-averaged CO2 mole fractions is smaller than that of the ground-based CO2 at all stations. The extrema of the seasonal cycle of ground-based and column CO2 mole fractions are basically synchronous except a slight phase delay at Lin'an (LAN) station. For the two-year average, the column CO2 is lower than ground-based CO2, and both of them reveal the lowest CO2 mole fraction at Waliguan (WLG) station. The lowest (∼4 ppm) and largest (∼8 ppm) differences between the column and ground-based CO2 appear at WLG and Longfengshan (LFS) stations, respectively. The CO2 mole fraction and its difference between GOSAT and ground-based measurement are smaller in summer than in winter. The differences of summer column CO2 among these stations are also much smaller than their ground-based counterparts. In winter, the maximum of ground-based CO2 mole fractions and the greatest difference between the two (ground-based and column) datasets appear at the LFS station. Secondly, the representative areas of the monthly CO2 background mole fractions at each station were found by employing footprints and emissions. Smaller representative areas appeared at Shangdianzi (SDZ) and LFS, whereas larger ones were seen at WLG and LAN. The representative areas in summer are larger than those in winter at WLG and SDZ, but the situation is opposite at LAN and LFS. The representative areas for the

International Space Station Sustaining Engineering: A Ground-Based Test Bed for Evaluating Integrated Environmental Control and Life Support System and Internal Thermal Control System Flight Performance

Science.gov (United States)

Ray, Charles D.; Perry, Jay L.; Callahan, David M.

2000-01-01

As the International Space Station's (ISS) various habitable modules are placed in service on orbit, the need to provide for sustaining engineering becomes increasingly important to ensure the proper function of critical onboard systems. Chief among these are the Environmental Control and Life Support System (ECLSS) and the Internal Thermal Control System (ITCS). Without either, life onboard the ISS would prove difficult or nearly impossible. For this reason, a ground-based ECLSS/ITCS hardware performance simulation capability has been developed at NASA's Marshall Space Flight Center. The ECLSS/ITCS Sustaining Engineering Test Bed will be used to assist the ISS Program in resolving hardware anomalies and performing periodic performance assessments. The ISS flight configuration being simulated by the test bed is described as well as ongoing activities related to its preparation for supporting ISS Mission 5A. Growth options for the test facility are presented whereby the current facility may be upgraded to enhance its capability for supporting future station operation well beyond Mission 5A. Test bed capabilities for demonstrating technology improvements of ECLSS hardware are also described.

Ground Motion Uncertainty and Variability (single-station sigma): Insights from Euroseistest, Greece

Science.gov (United States)

Ktenidou, O. J.; Roumelioti, Z.; Abrahamson, N. A.; Cotton, F.; Pitilakis, K.

2014-12-01

Despite recent improvements in networks and data, the global aleatory uncertainty (sigma) in GMPEs is still large. One reason is the ergodic approach, where we combine data in space to make up for lack of data in time. By estimating the systematic site response, we can make site-specific GMPEs and use a lower, site-specific uncertainty: single-station sigma. In this study we use the EUROSEISTEST database (http://euroseisdb.civil.auth.gr), which has two distinct advantages: good existing knowledge of site conditions at all stations, and careful relocation of the recorded events. Constraining the site and source parameters as best we can, we minimise the within- and between-events components of the global, ergodic sigma. Following that, knowledge of the site response from empirical and theoretical approaches permits us to move on to single-station sigma. The variability per site is not clearly correlated to the site class. We show that in some cases knowledge of Vs30 is not sufficient, and that site-specific data are needed to capture the response, possibly due to 2D/3D effects from complex geometry. Our values of single-station sigma are low compared to the literature. This may be due to the good ray coverage we have in all directions for small, nearby records. Indeed, our single-station sigma values are similar to published single-path values, which means that they may correspond to a fully -rather than partially- non-ergodic approach. We find larger ground motion variability for short distances and small magnitudes. This may be related to the uncertainty in the depth affecting nearby records more, or to stress drop and causing trade-offs between the source and site terms for small magnitudes.

Ground-based observations coordinated with Viking satellite measurements

International Nuclear Information System (INIS)

Opgenoorth, H.J.; Kirkwood, S.

1989-01-01

The instrumentation and the orbit of the Viking satellite made this first Swedish satellite mission ideally suited for coordinated observations with the dense network of ground-based stations in northern Scandinavia. Several arrays of complementing instruments such as magnetometers, all-sky cameras, riometers and doppler radars monitored on a routine basis the ionosphere under the magnetospheric region passed by Viking. For a large number of orbits the Viking passages close to Scandinavia were covered by the operation of specially designed programmes at the European incoherent-scatter facility (EISCAT). First results of coordinated observations on the ground and aboard Viking have shed new light on the most spectacular feature of substorm expansion, the westward-travelling surge. The end of a substorm and the associated decay of a westward-travelling surge have been analysed. EISCAT measurements of high spatial and temporal resolution indicate that the conductivities and electric fields associated with westward-travelling surges are not represented correctly by the existing models. (author)

Definition of technology development missions for early space stations orbit transfer vehicle serving. Phase 2, task 1: Space station support of operational OTV servicing

Science.gov (United States)

1983-01-01

Representative space based orbital transfer vehicles (OTV), ground based vehicle turnaround assessment, functional operational requirements and facilities, mission turnaround operations, a comparison of ground based versus space based tasks, activation of servicing facilities prior to IOC, fleet operations requirements, maintenance facilities, OTV servicing facilities, space station support requirements, and packaging for delivery are discussed.

A method for optical ground station reduce alignment error in satellite-ground quantum experiments

Science.gov (United States)

He, Dong; Wang, Qiang; Zhou, Jian-Wei; Song, Zhi-Jun; Zhong, Dai-Jun; Jiang, Yu; Liu, Wan-Sheng; Huang, Yong-Mei

2018-03-01

A satellite dedicated for quantum science experiments, has been developed and successfully launched from Jiuquan, China, on August 16, 2016. Two new optical ground stations (OGSs) were built to cooperate with the satellite to complete satellite-ground quantum experiments. OGS corrected its pointing direction by satellite trajectory error to coarse tracking system and uplink beacon sight, therefore fine tracking CCD and uplink beacon optical axis alignment accuracy was to ensure that beacon could cover the quantum satellite in all time when it passed the OGSs. Unfortunately, when we tested specifications of the OGSs, due to the coarse tracking optical system was commercial telescopes, the change of position of the target in the coarse CCD was up to 600μrad along with the change of elevation angle. In this paper, a method of reduce alignment error between beacon beam and fine tracking CCD is proposed. Firstly, OGS fitted the curve of target positions in coarse CCD along with the change of elevation angle. Secondly, OGS fitted the curve of hexapod secondary mirror positions along with the change of elevation angle. Thirdly, when tracking satellite, the fine tracking error unloaded on the real-time zero point position of coarse CCD which computed by the firstly calibration data. Simultaneously the positions of the hexapod secondary mirror were adjusted by the secondly calibration data. Finally the experiment result is proposed. Results show that the alignment error is less than 50μrad.

Soil moisture characterization of the Valencia anchor station. Ground, aircraft measurements and simulations

DEFF Research Database (Denmark)

Lopez-Baeza, E; Antolin, M C; Balling, Jan E.

2009-01-01

In the framework of ESA SMOS Mission, the Valencia Anchor Station (VAS) has been selected as a core validation site. Its reasonable homogeneous characteristics make it appropriate to undertake the validation of SMOS Level 2 land products before attempting other more complex areas. Close to SMOS...... launch (2nd Nov. 2009), ESA defined the SMOS Validation Rehearsal Campaign Plan with the aim of testing the readiness, ensemble coordination and speed of operations, to be able to avoid as far as possible any unexpected deficiencies of the plan and procedure during the real Commissioning Phase campaigns......). Together with the ground SM measurements, other ground and meteorological measurements from the VAS area, kindly provided by other institutions, are currently been used to simulate passive microwave brightness temperature to obtain satellite "match ups" for validation purposes and to test the retrieval...

MODELING ATMOSPHERIC EMISSION FOR CMB GROUND-BASED OBSERVATIONS

Energy Technology Data Exchange (ETDEWEB)

Errard, J.; Borrill, J. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Ade, P. A. R. [School of Physics and Astronomy, Cardiff University, Cardiff CF10 3XQ (United Kingdom); Akiba, Y.; Chinone, Y. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Arnold, K.; Atlas, M.; Barron, D.; Elleflot, T. [Department of Physics, University of California, San Diego, CA 92093-0424 (United States); Baccigalupi, C.; Fabbian, G. [International School for Advanced Studies (SISSA), Trieste I-34014 (Italy); Boettger, D. [Department of Astronomy, Pontifica Universidad Catolica de Chile (Chile); Chapman, S. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, B3H 4R2 (Canada); Cukierman, A. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Delabrouille, J. [AstroParticule et Cosmologie, Univ Paris Diderot, CNRS/IN2P3, CEA/Irfu, Obs de Paris, Sorbonne Paris Cité (France); Dobbs, M.; Gilbert, A. [Physics Department, McGill University, Montreal, QC H3A 0G4 (Canada); Ducout, A.; Feeney, S. [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); Feng, C. [Department of Physics and Astronomy, University of California, Irvine (United States); and others

2015-08-10

Atmosphere is one of the most important noise sources for ground-based cosmic microwave background (CMB) experiments. By increasing optical loading on the detectors, it amplifies their effective noise, while its fluctuations introduce spatial and temporal correlations between detected signals. We present a physically motivated 3D-model of the atmosphere total intensity emission in the millimeter and sub-millimeter wavelengths. We derive a new analytical estimate for the correlation between detectors time-ordered data as a function of the instrument and survey design, as well as several atmospheric parameters such as wind, relative humidity, temperature and turbulence characteristics. Using an original numerical computation, we examine the effect of each physical parameter on the correlations in the time series of a given experiment. We then use a parametric-likelihood approach to validate the modeling and estimate atmosphere parameters from the polarbear-i project first season data set. We derive a new 1.0% upper limit on the linear polarization fraction of atmospheric emission. We also compare our results to previous studies and weather station measurements. The proposed model can be used for realistic simulations of future ground-based CMB observations.

Ground-water flow in the surficial aquifer system and potential movement of contaminants from selected waste-disposal sites at Naval Station Mayport, Florida

Science.gov (United States)

Halford, K.J.

1998-01-01

Ground-water flow through the surficial aquifer system at Naval Station Mayport near Jacksonville, Florida, was simulated with a two-layer finite-difference model as part of an investigation conducted by the U.S. Geological Survey. The model was calibrated to 229 water-level measurements from 181 wells during three synoptic surveys (July 17, 1995; July 31, 1996; and October 24, 1996). A quantifiable understanding of ground-water flow through the surficial aquifer was needed to evaluate remedial-action alternatives under consideration by the Naval Station Mayport to control the possible movement of contaminants from sites on the station. Multi-well aquifer tests, single-well tests, and slug tests were conducted to estimate the hydraulic properties of the surficial aquifer system, which was divided into three geohydrologic units?an S-zone and an I-zone separated by a marsh-muck confining unit. The recharge rate was estimated to range from 4 to 15 inches per year (95 percent confidence limits), based on a chloride-ratio method. Most of the simulations following model calibration were based on a recharge rate of 8 inches per year to unirrigated pervious areas. The advective displacement of saline pore water during the last 200 years was simulated using a particle-tracking routine, MODPATH, applied to calibrated steady-state and transient models of the Mayport peninsula. The surficial aquifer system at Naval Station Mayport has been modified greatly by natural and anthropogenic forces so that the freshwater flow system is expanding and saltwater is being flushed from the system. A new MODFLOW package (VAR1) was written to simulate the temporal variation of hydraulic properties caused by construction activities at Naval Station Mayport. The transiently simulated saltwater distribution after 200 years of displacement described the chloride distribution in the I-zone (determined from measurements made during 1993 and 1996) better than the steady-state simulation. The

Characterisation of ground motion recording stations in the Groningen gas field

Science.gov (United States)

Noorlandt, Rik; Kruiver, Pauline P.; de Kleine, Marco P. E.; Karaoulis, Marios; de Lange, Ger; Di Matteo, Antonio; von Ketelhodt, Julius; Ruigrok, Elmer; Edwards, Benjamin; Rodriguez-Marek, Adrian; Bommer, Julian J.; van Elk, Jan; Doornhof, Dirk

2018-05-01

The seismic hazard and risk analysis for the onshore Groningen gas field requires information about local soil properties, in particular shear-wave velocity ( V S). A fieldwork campaign was conducted at 18 surface accelerograph stations of the monitoring network. The subsurface in the region consists of unconsolidated sediments and is heterogeneous in composition and properties. A range of different methods was applied to acquire in situ V S values to a target depth of at least 30 m. The techniques include seismic cone penetration tests (SCPT) with varying source offsets, multichannel analysis of surface waves (MASW) on Rayleigh waves with different processing approaches, microtremor array, cross-hole tomography and suspension P-S logging. The offset SCPT, cross-hole tomography and common midpoint cross-correlation (CMPcc) processing of MASW data all revealed lateral variations on length scales of several to tens of metres in this geological setting. SCPTs resulted in very detailed V S profiles with depth, but represent point measurements in a heterogeneous environment. The MASW results represent V S information on a larger spatial scale and smooth some of the heterogeneity encountered at the sites. The combination of MASW and SCPT proved to be a powerful and cost-effective approach in determining representative V S profiles at the accelerograph station sites. The measured V S profiles correspond well with the modelled profiles and they significantly enhance the ground motion model derivation. The similarity between the theoretical transfer function from the V S profile and the observed amplification from vertical array stations is also excellent.

An analysis of spatial representativeness of air temperature monitoring stations

Science.gov (United States)

Liu, Suhua; Su, Hongbo; Tian, Jing; Wang, Weizhen

2018-05-01

Surface air temperature is an essential variable for monitoring the atmosphere, and it is generally acquired at meteorological stations that can provide information about only a small area within an r m radius ( r-neighborhood) of the station, which is called the representable radius. In studies on a local scale, ground-based observations of surface air temperatures obtained from scattered stations are usually interpolated using a variety of methods without ascertaining their effectiveness. Thus, it is necessary to evaluate the spatial representativeness of ground-based observations of surface air temperature before conducting studies on a local scale. The present study used remote sensing data to estimate the spatial distribution of surface air temperature using the advection-energy balance for air temperature (ADEBAT) model. Two target stations in the study area were selected to conduct an analysis of spatial representativeness. The results showed that one station (AWS 7) had a representable radius of about 400 m with a possible error of less than 1 K, while the other station (AWS 16) had the radius of about 250 m. The representable radius was large when the heterogeneity of land cover around the station was small.

Different Multifractal Scaling of the 0 cm Average Ground Surface Temperature of Four Representative Weather Stations over China

Directory of Open Access Journals (Sweden)

Lei Jiang

2013-01-01

Full Text Available The temporal scaling properties of the daily 0 cm average ground surface temperature (AGST records obtained from four selected sites over China are investigated using multifractal detrended fluctuation analysis (MF-DFA method. Results show that the AGST records at all four locations exhibit strong persistence features and different scaling behaviors. The differences of the generalized Hurst exponents are very different for the AGST series of each site reflecting the different scaling behaviors of the fluctuation. Furthermore, the strengths of multifractal spectrum are different for different weather stations and indicate that the multifractal behaviors vary from station to station over China.

Confirmation test on the dynamic interaction between a model reactor-building foundation and ground in the Sendai Nuclear Power Station

International Nuclear Information System (INIS)

Umezu, Hideo; Kisaki, Noboru; Shiota, Mutsumi

1982-01-01

On the site of unit 2 (planned) in the Sendai Nuclear Power Station, a model reactor-building foundation of reinforced concrete with diameter of 12 m and height of 5 m was installed. With a vibration generator, its forced vibration tests were carried out in October to December, 1980. Valuable data were able to be obtained on the dynamic interaction between the model foundation and the ground, and also the outlook for the application of theories in hard base rock was obtained. (1) The resonance frequency of the model foundation in horizontal vibration was 35 Hz in both NS and EW directions. (2) Remarkable difference was not observed in the horizontal vibration behavior between NS and EW directions, so that there is not anisotropy in the ground. (3) The model foundation was deformed nearly as a rigid body. (J.P.N.)

Geocenter variations derived from a combined processing of LEO- and ground-based GPS observations

Science.gov (United States)

Männel, Benjamin; Rothacher, Markus

2017-08-01

GNSS observations provided by the global tracking network of the International GNSS Service (IGS, Dow et al. in J Geod 83(3):191-198, 2009) play an important role in the realization of a unique terrestrial reference frame that is accurate enough to allow a detailed monitoring of the Earth's system. Combining these ground-based data with GPS observations tracked by high-quality dual-frequency receivers on-board low earth orbiters (LEOs) is a promising way to further improve the realization of the terrestrial reference frame and the estimation of geocenter coordinates, GPS satellite orbits and Earth rotation parameters. To assess the scope of the improvement on the geocenter coordinates, we processed a network of 53 globally distributed and stable IGS stations together with four LEOs (GRACE-A, GRACE-B, OSTM/Jason-2 and GOCE) over a time interval of 3 years (2010-2012). To ensure fully consistent solutions, the zero-difference phase observations of the ground stations and LEOs were processed in a common least-squares adjustment, estimating all the relevant parameters such as GPS and LEO orbits, station coordinates, Earth rotation parameters and geocenter motion. We present the significant impact of the individual LEO and a combination of all four LEOs on the geocenter coordinates. The formal errors are reduced by around 20% due to the inclusion of one LEO into the ground-only solution, while in a solution with four LEOs LEO-specific characteristics are significantly reduced. We compare the derived geocenter coordinates w.r.t. LAGEOS results and external solutions based on GPS and SLR data. We found good agreement in the amplitudes of all components; however, the phases in x- and z-direction do not agree well.

Optical studies in the holographic ground station

Science.gov (United States)

Workman, Gary L.

1991-01-01

The Holographic Group System (HGS) Facility in rooms 22 & 123, Building 4708 has been developed to provide for ground based research in determining pre-flight parameters and analyzing the results from space experiments. The University of Alabama, Huntsville (UAH) has researched the analysis aspects of the HGS and reports their findings here. Some of the results presented here also occur in the Facility Operating Procedure (FOP), which contains instructions for power up, operation, and powerdown of the Fluid Experiment System (FES) Holographic Ground System (HGS) Test Facility for the purpose of optically recording fluid and/or crystal behavior in a test article during ground based testing through the construction of holograms and recording of videotape. The alignment of the optical bench components, holographic reconstruction and and microscopy alignment sections were also included in the document for continuity even though they are not used until after optical recording of the test article) setup of support subsystems and the Automated Holography System (AHS) computer. The HGS provides optical recording and monitoring during GCEL runs or development testing of potential FES flight hardware or software. This recording/monitoring can be via 70mm holographic film, standard videotape, or digitized images on computer disk. All optical bench functions necessary to construct holograms will be under the control of the AHS personal computer (PC). These include type of exposure, time intervals between exposures, exposure length, film frame identification, film advancement, film platen evacuation and repressurization, light source diffuser introduction, and control of realtime video monitoring. The completed sequence of hologram types (single exposure, diffuse double exposure, etc.) and their time of occurrence can be displayed, printed, or stored on floppy disk posttest for the user.

Summary of astronaut inputs on automation and robotics for Space Station Freedom

Science.gov (United States)

Weeks, David J.

1990-01-01

Astronauts and payload specialists present specific recommendations in the form of an overview that relate to the use of automation and robotics on the Space Station Freedom. The inputs are based on on-orbit operations experience, time requirements for crews, and similar crew-specific knowledge that address the impacts of automation and robotics on productivity. Interview techniques and specific questionnaire results are listed, and the majority of the responses indicate that incorporating automation and robotics to some extent and with human backup can improve productivity. Specific support is found for the use of advanced automation and EVA robotics on the Space Station Freedom and for the use of advanced automation on ground-based stations. Ground-based control of in-flight robotics is required, and Space Station activities and crew tasks should be analyzed to assess the systems engineering approach for incorporating automation and robotics.

Validation of OMI UV measurements against ground-based measurements at a station in Kampala, Uganda

Science.gov (United States)

Muyimbwa, Dennis; Dahlback, Arne; Stamnes, Jakob; Hamre, Børge; Frette, Øyvind; Ssenyonga, Taddeo; Chen, Yi-Chun

2015-04-01

We present solar ultraviolet (UV) irradiance data measured with a NILU-UV instrument at a ground site in Kampala (0.31°N, 32.58°E), Uganda for the period 2005-2014. The data were analyzed and compared with UV irradiances inferred from the Ozone Monitoring Instrument (OMI) for the same period. Kampala is located on the shores of lake Victoria, Africa's largest fresh water lake, which may influence the climate and weather conditions of the region. Also, there is an excessive use of worn cars, which may contribute to a high anthropogenic loading of absorbing aerosols. The OMI surface UV algorithm does not account for absorbing aerosols, which may lead to systematic overestimation of surface UV irradiances inferred from OMI satellite data. We retrieved UV index values from OMI UV irradiances and validated them against the ground-based UV index values obtained from NILU-UV measurements. The UV index values were found to follow a seasonal pattern similar to that of the clouds and the rainfall. OMI inferred UV index values were overestimated with a mean bias of about 28% under all-sky conditions, but the mean bias was reduced to about 8% under clear-sky conditions when only days with radiation modification factor (RMF) greater than 65% were considered. However, when days with RMF greater than 70, 75, and 80% were considered, OMI inferred UV index values were found to agree with the ground-based UV index values to within 5, 3, and 1%, respectively. In the validation we identified clouds/aerosols, which were present in 88% of the measurements, as the main cause of OMI inferred overestimation of the UV index.

Gsm 1900Umts Printed Monopole Antenna For Mobile Base Station

Directory of Open Access Journals (Sweden)

Nyi Nyi Lwin

2015-08-01

Full Text Available In this paper printed rectangular monopole antenna which is basically printed microstrip patch antenna with partial ground plane is designed for mobile base station. The substrate FR4 with a relative permittivity of 4.4 and thickness 1.8 is used in design. In addition the printed monopole antenna is of low profile in appearance and suitable for most application. The proposed antenna can cover GSM1900 1850-1990 MHz and UMTS 1920-2170 MHz bands. Design and simulation processes are carried out with the aid of FEKO software which is used for the analysis of electromagnetic problems. Simulation results of the return loss gain and radiation patterns are presented.

Ground-based transmission line conductor motion sensor

International Nuclear Information System (INIS)

Jacobs, M.L.; Milano, U.

1988-01-01

A ground-based-conductor motion-sensing apparatus is provided for remotely sensing movement of electric-power transmission lines, particularly as would occur during the wind-induced condition known as galloping. The apparatus is comprised of a motion sensor and signal-generating means which are placed underneath a transmission line and will sense changes in the electric field around the line due to excessive line motion. The detector then signals a remote station when a conditioning of galloping is sensed. The apparatus of the present invention is advantageous over the line-mounted sensors of the prior art in that it is easier and less hazardous to install. The system can also be modified so that a signal will only be given when particular conditions, such as specific temperature range, large-amplitude line motion, or excessive duration of the line motion, are occurring

Temporal Variability of Total Ozone in the Asian Region Inferred from Ground-Based and Satellite Measurement Data

Science.gov (United States)

Visheratin, K. N.; Nerushev, A. F.; Orozaliev, M. D.; Zheng, Xiangdong; Sun, Shumen; Liu, Li

2017-12-01

This paper reports investigation data on the temporal variability of total ozone content (TOC) in the Central Asian and Tibet Plateau mountain regions obtained by conventional methods, as well as by spectral, cross-wavelet, and composite analyses. The data of ground-based observation stations located at Huang He, Kunming, and Lake Issyk-Kul, along with the satellite data obtained at SBUV/SBUV2 (SBUV merged total and profile ozone data, Version 8.6) for 1980-2013 and OMI (Ozone Monitoring Instrument) and TOU (Total Ozone Unit) for 2009-2013 have been used. The average relative deviation from the SBUV/SBUV2 data is less than 1% in Kunming and Issyk-Kul for the period of 1980-2013, while the Huang He Station is characterized by an excess of the satellite data over the ground-based information at an average deviation of 2%. According to the Fourier analysis results, the distribution of amplitudes and the periods of TOC oscillations within a range of over 14 months is similar for all series analyzed. Meanwhile, according to the cross-wavelet and composite analyses results, the phase relationships between the series may considerably differ, especially in the periods of 5-7 years. The phase of quasi-decennial oscillations in the Kunming Station is close to the 11-year oscillations of the solar cycle, while in the Huang He and Issyk-Kul stations the TOC variations go ahead of the solar cycle.

Advanced Software Ground Station and UAV Development for NLoS Control Using Mobile Communications

Directory of Open Access Journals (Sweden)

Amr AbdElHamid

2015-01-01

Full Text Available Over the last decades, Unmanned Aerial Systems (UASs have gained much attention due to their various applications in different sections. However, their communication range is limited to utilized communication equipment. Therefore, utilization of GSM channels opens a new prospect towards long distance UAV missions and mobile command and control centers. This paper demonstrates new design and development of a small-scale UAV and a Ground Control Station (GCS using GSM bidirectional communications for Non-Line of Sight (NLoS long range control. GCSs are considered the front end node in UAV guidance process. Therefore, the proposed GCS employs a two-layer framework to consider all ground pilot requirements. Moreover, a new exploitation of global weather forecast data is added to the GCS. On the other hand, the proposed airborne system utilizes a new integration of different Commercial off-the-Shelf (COTS components and excludes short range receivers. The ground and flight tests show that stable bidirectional GSM communication is established, reliable hardware integration is accomplished, real time performance is achieved, GCS functional fidelity is obtained, and low cost is maintained. Finally, some qualitative aspects of the proposed platform are presented to address the detailed features.

Depolarization ratio of polar stratospheric clouds in coastal Antarctica: comparison analysis between ground-based Micro Pulse Lidar and space-borne CALIOP observations

Directory of Open Access Journals (Sweden)

C. Córdoba-Jabonero

2013-03-01

Full Text Available Polar stratospheric clouds (PSCs play an important role in polar ozone depletion, since they are involved in diverse ozone destruction processes (chlorine activation, denitrification. The degree of that ozone reduction is depending on the type of PSCs, and hence on their occurrence. Therefore PSC characterization, mainly focused on PSC-type discrimination, is widely demanded. The backscattering (R and volume linear depolarization (δV ratios are the parameters usually used in lidar measurements for PSC detection and identification. In this work, an improved version of the standard NASA/Micro Pulse Lidar (MPL-4, which includes a built-in depolarization detection module, has been used for PSC observations above the coastal Antarctic Belgrano II station (Argentina, 77.9° S 34.6° W, 256 m a.s.l. since 2009. Examination of the MPL-4 δV feature as a suitable index for PSC-type discrimination is based on the analysis of the two-channel data, i.e., the parallel (p- and perpendicular (s- polarized MPL signals. This study focuses on the comparison of coincident δV-profiles as obtained from ground-based MPL-4 measurements during three Antarctic winters with those reported from the space-borne lidar CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellite in the same period (83 simultaneous cases are analysed for 2009–2011 austral winter times. Three different approaches are considered for the comparison analysis between both lidar profile data sets in order to test the degree of agreement: the correlation coefficient (CC, as a measure of the relationship between both PSC vertical structures; the mean differences together with their root mean square (RMS values found between data sets; and the percentage differences (BIAS, parameter also used in profiling comparisons between CALIOP and other ground-based lidar systems. All of them are examined as a function

Satellite and Ground-Based Sensors for the Urban Heat Island Analysis in the City of Rome

Directory of Open Access Journals (Sweden)

Roberto Fabrizi

2010-05-01

Full Text Available In this work, the trend of the Urban Heat Island (UHI of Rome is analyzed by both ground-based weather stations and a satellite-based infrared sensor. First, we have developed a suitable algorithm employing satellite brightness temperatures for the estimation of the air temperature belonging to the layer of air closest to the surface. UHI spatial characteristics have been assessed using air temperatures measured by both weather stations and brightness temperature maps from the Advanced Along Track Scanning Radiometer (AATSR on board ENVISAT polar-orbiting satellite. In total, 634 daytime and nighttime scenes taken between 2003 and 2006 have been processed. Analysis of the Canopy Layer Heat Island (CLHI during summer months reveals a mean growth in magnitude of 3–4 K during nighttime and a negative or almost zero CLHI intensity during daytime, confirmed by the weather stations.

User Context Aware Base Station Power Flow Model

OpenAIRE

Walsh, Barbara; Farrell, Ronan

2005-01-01

At present the testing of power amplifiers within base station transmitters is limited to testing at component level as opposed to testing at the system level. While the detection of catastrophic failure is possible, that of performance degradation is not. This paper proposes a base station model with respect to transmitter output power with the aim of introducing system level monitoring of the power amplifier behaviour within the base station. Our model reflects the expe...

Effect of earthquake and tsunami. Ground motion and tsunami observed at nuclear power station

International Nuclear Information System (INIS)

Hijikata, Katsuichirou

2012-01-01

Fukushima Daiichi and Daini Nuclear Power Stations (NPSs) were struck by the earthquake off the pacific coast in the Tohoku District, which occurred at 14:46 on March 11, 2011. Afterwards, tsunamis struck the Tohoku District. In terms of the earthquake observed at the Fukushima NPSs, the acceleration response spectra of the earthquake movement observed on the basic board of reactor buildings exceeded the acceleration response spectra of the response acceleration to the standard seismic ground motion Ss for partial periodic bands at the Fukushima Daiichi NPS. As for the Fukushima Daini NPS, the acceleration response spectra of the earthquake movement observed on the basic board of the reactor buildings was below the acceleration response spectra of the response acceleration to the standard seismic ground motion Ss. Areas inundated by Tsunami at each NPS were investigated and tsunami inversion analysis was made to build tsunami source model to reproduce tide record, tsunami height, crustal movement and inundated area, based on tsunami observation records in the wide areas from Hokkaido to Chiba prefectures. Tsunami heights of Fukushima Daiichi and Daini NPSs were recalculated as O.P. +13m and +9m respectively and tsunami peak height difference was attributed to the extent of superposition of tsunami waves of tsunami earthquake type of wave source in the area along interplane trench off the coast in the Fukushima prefecture and interplane earthquake type of wave source in rather deep interplate area off the coast in the Miyagi prefecture. (T. Tanaka)

Ground-based photo monitoring

Science.gov (United States)

Frederick C. Hall

2000-01-01

Ground-based photo monitoring is repeat photography using ground-based cameras to document change in vegetation or soil. Assume those installing the photo location will not be the ones re-photographing it. This requires a protocol that includes: (1) a map to locate the monitoring area, (2) another map diagramming the photographic layout, (3) type and make of film such...

Mojave Base Station Implementation

Science.gov (United States)

Koscielski, C. G.

1984-01-01

A 12.2 meter diameter X-Y mount antenna was reconditioned for use by the crustal dynamic project as a fixed base station. System capabilities and characteristics and key performance parameters for subsystems are presented. The implementation is completed.

An SINS/GNSS Ground Vehicle Gravimetry Test Based on SGA-WZ02

Directory of Open Access Journals (Sweden)

Ruihang Yu

2015-09-01

Full Text Available In March 2015, a ground vehicle gravimetry test was implemented in eastern Changsha to assess the repeatability and accuracy of ground vehicle SINS/GNSS gravimeter—SGA-WZ02. The gravity system developed by NUDT consisted of a Strapdown Inertial Navigation System (SINS, a Global Navigation Satellite System (GNSS remote station on test vehicle, a GNSS static master station on the ground, and a data logging subsystem. A south-north profile of 35 km along the highway in eastern Changsha was chosen and four repeated available measure lines were obtained. The average speed of a vehicle is 40 km/h. To assess the external ground gravity disturbances, precise ground gravity data was built by CG-5 precise gravimeter as the reference. Under relative smooth conditions, internal accuracy among repeated lines shows an average agreement at the level of 1.86 mGal for half wavelengths about 1.1 km, and 1.22 mGal for 1.7 km. The root-mean-square (RMS of difference between calculated gravity data and reference data is about 2.27 mGal/1.1 km, and 1.74 mGal/1.7 km. Not all of the noises caused by vehicle itself and experiments environments were eliminated in the primary results. By means of selecting reasonable filters and improving the GNSS observation conditions, further developments in ground vehicle gravimetry are promising.

Analysis of transmission speed of AX.25 Protocol implemented in satellital earth station UPTC

Directory of Open Access Journals (Sweden)

Oscar Fernando Vera Cely

2015-11-01

Full Text Available One of the important parameters for the proper functioning of satellital ground station projected on Pedagogical and Technological University of Colombia (UPTC is the efficiency in transmission speed on communications protocol. This paper shows the results of analysis of the transmission speed of the AX.25 protocol implemented in the communication system of the satellital ground station UPTC. It begins with a brief description of the implemented hardware; the behavior of the transmission rate is evaluated using a theoretical analysis based on equations to estimate this parameter in the operation of the protocol, then tests are performed using the hardware that the satellital ground station UPTC has and finally, the conclusions are presented. Based on comparison of the theoretical analysis results obtained experimentally, it became apparent that AX.25 protocol efficiency is higher when increasing the number of frames.

Schedule Optimization of Imaging Missions for Multiple Satellites and Ground Stations Using Genetic Algorithm

Science.gov (United States)

Lee, Junghyun; Kim, Heewon; Chung, Hyun; Kim, Haedong; Choi, Sujin; Jung, Okchul; Chung, Daewon; Ko, Kwanghee

2018-04-01

In this paper, we propose a method that uses a genetic algorithm for the dynamic schedule optimization of imaging missions for multiple satellites and ground systems. In particular, the visibility conflicts of communication and mission operation using satellite resources (electric power and onboard memory) are integrated in sequence. Resource consumption and restoration are considered in the optimization process. Image acquisition is an essential part of satellite missions and is performed via a series of subtasks such as command uplink, image capturing, image storing, and image downlink. An objective function for optimization is designed to maximize the usability by considering the following components: user-assigned priority, resource consumption, and image-acquisition time. For the simulation, a series of hypothetical imaging missions are allocated to a multi-satellite control system comprising five satellites and three ground stations having S- and X-band antennas. To demonstrate the performance of the proposed method, simulations are performed via three operation modes: general, commercial, and tactical.

Electron and ion temperatures: a comparison of ground-based incoherent scatter and AE-C satellite measurements

International Nuclear Information System (INIS)

Benson, R.F.; Bauer, P.; Brace, L.H.; Carlson, H.C.; Hagen, J.; Hanson, W.B.; Hoegy, W.R.; Torr, M.R.; Wickwar, V.B.

1977-01-01

The Atmosphere Exploere-C satellite (AE-C) is uniquely suited for correlative studies with ground-based stations because its on-board propulsion system enables a desired ground station overflight condition to be maintained for a period of several weeks. It also provides the first low-altitude (below 260 km) comparison of satellite and incoherent scatter electron and ion temperatures. More than 40 comparisons of remote and in situ measurements were made by using data from AE-C and four incoherent scatter stations (Arecibo, Chatanika, Millstone Hill, and St. Santin). The results indicate very good agreement between satellite and ground measurements of the ion temperature, the average satellite retarding potential analyzer temperatures differing from the average incoherent scatter temperatures by -2% at St. Santin, +3% at Millstone Hill, and +2% at Arecibo. The electron temperatures also agree well, the average satellite temperatures exceeding the average incoherent scatter temperatures by 3% at St. Santin, 2% at Arecibo, and 11% at Millstone Hill. Several temperature comparisons were made between AE-C and Chatanika. In spite of the highly variable ionosphere often encountered at this high-latitude location, good agreement was obtained between the in situ and remote measurements of electron and ion temperatures. Longitudinal variations are found to be very important in the comparisons of electron temperature in some locations. The agreement between the electron temperatures is considerably better than that found in some earlier comparisons involving satellities at higher altitudes

Analysis of large optical ground stations for deep-space optical communications

Science.gov (United States)

Garcia-Talavera, M. Reyes; Rivera, C.; Murga, G.; Montilla, I.; Alonso, A.

2017-11-01

Inter-satellite and ground to satellite optical communications have been successfully demonstrated over more than a decade with several experiments, the most recent being NASA's lunar mission Lunar Atmospheric Dust Environment Explorer (LADEE). The technology is in a mature stage that allows to consider optical communications as a high-capacity solution for future deep-space communications [1][2], where there is an increasing demand on downlink data rate to improve science return. To serve these deep-space missions, suitable optical ground stations (OGS) have to be developed providing large collecting areas. The design of such OGSs must face both technical and cost constraints in order to achieve an optimum implementation. To that end, different approaches have already been proposed and analyzed, namely, a large telescope based on a segmented primary mirror, telescope arrays, and even the combination of RF and optical receivers in modified versions of existing Deep-Space Network (DSN) antennas [3][4][5]. Array architectures have been proposed to relax some requirements, acting as one of the key drivers of the present study. The advantages offered by the array approach are attained at the expense of adding subsystems. Critical issues identified for each implementation include their inherent efficiency and losses, as well as its performance under high-background conditions, and the acquisition, pointing, tracking, and synchronization capabilities. It is worth noticing that, due to the photon-counting nature of detection, the system performance is not solely given by the signal-to-noise ratio parameter. To start with the analysis, first the main implications of the deep space scenarios are summarized, since they are the driving requirements to establish the technical specifications for the large OGS. Next, both the main characteristics of the OGS and the potential configuration approaches are presented, getting deeper in key subsystems with strong impact in the

Thoracic lymph node station recognition on CT images based on automatic anatomy recognition with an optimal parent strategy

Science.gov (United States)

Xu, Guoping; Udupa, Jayaram K.; Tong, Yubing; Cao, Hanqiang; Odhner, Dewey; Torigian, Drew A.; Wu, Xingyu

2018-03-01

Currently, there are many papers that have been published on the detection and segmentation of lymph nodes from medical images. However, it is still a challenging problem owing to low contrast with surrounding soft tissues and the variations of lymph node size and shape on computed tomography (CT) images. This is particularly very difficult on low-dose CT of PET/CT acquisitions. In this study, we utilize our previous automatic anatomy recognition (AAR) framework to recognize the thoracic-lymph node stations defined by the International Association for the Study of Lung Cancer (IASLC) lymph node map. The lymph node stations themselves are viewed as anatomic objects and are localized by using a one-shot method in the AAR framework. Two strategies have been taken in this paper for integration into AAR framework. The first is to combine some lymph node stations into composite lymph node stations according to their geometrical nearness. The other is to find the optimal parent (organ or union of organs) as an anchor for each lymph node station based on the recognition error and thereby find an overall optimal hierarchy to arrange anchor organs and lymph node stations. Based on 28 contrast-enhanced thoracic CT image data sets for model building, 12 independent data sets for testing, our results show that thoracic lymph node stations can be localized within 2-3 voxels compared to the ground truth.

Single-Station Sigma for the Iranian Strong Motion Stations

Science.gov (United States)

Zafarani, H.; Soghrat, M. R.

2017-11-01

In development of ground motion prediction equations (GMPEs), the residuals are assumed to have a log-normal distribution with a zero mean and a standard deviation, designated as sigma. Sigma has significant effect on evaluation of seismic hazard for designing important infrastructures such as nuclear power plants and dams. Both aleatory and epistemic uncertainties are involved in the sigma parameter. However, ground-motion observations over long time periods are not available at specific sites and the GMPEs have been derived using observed data from multiple sites for a small number of well-recorded earthquakes. Therefore, sigma is dominantly related to the statistics of the spatial variability of ground motion instead of temporal variability at a single point (ergodic assumption). The main purpose of this study is to reduce the variability of the residuals so as to handle it as epistemic uncertainty. In this regard, it is tried to partially apply the non-ergodic assumption by removing repeatable site effects from total variability of six GMPEs driven from the local, Europe-Middle East and worldwide data. For this purpose, we used 1837 acceleration time histories from 374 shallow earthquakes with moment magnitudes ranging from M w 4.0 to 7.3 recorded at 370 stations with at least two recordings per station. According to estimated single-station sigma for the Iranian strong motion stations, the ratio of event-corrected single-station standard deviation ( Φ ss) to within-event standard deviation ( Φ) is about 0.75. In other words, removing the ergodic assumption on site response resulted in 25% reduction of the within-event standard deviation that reduced the total standard deviation by about 15%.

REDISTRIBUTION OF BASE STATIONS LOAD IN MOBILE COMMUNICATION NETWORKS

Directory of Open Access Journals (Sweden)

Igor Ruban

2017-09-01

Full Text Available The subject matter of the article is the processes of load distribution in mobile communication networks. The object of research is the handover. The goal is to develop a method for redistributing the load between neighboring areas for mobile nodes. The considered base stations are supposed to have the signal-to-noise ratios that are equal or close. The methods that are used: methods of system analysis, methods of digital signal processing. The following results are obtained. The method that allows mobile nodes, whose signal-to-noise ratios are equal or close, to switch to a less loaded base station. This method allows the base station to launch the handover process enabling more even distribution of the load from mobile nodes among neighboring base stations in wireless and mobile networks. In the suggested modification of the method, the function assessing the bandwidth of the uplink channel is added to the base stations, as well a threshold value for using its bandwidth. Thus, when the current value of bandwidth reaches the threshold, the base station starts sending out a message to all mobile nodes and verifies free neighboring areas for switching over mobile nodes. If there are adjacent areas with a lower load, the base station notifies all potential candidates about the necessity of their switching over. The handover process is launched when the available bandwidth of the base station decreases below a certain threshold. Therefore, it is possible to optimize the operation of the WiMAX network with respect to the criterion of the total bandwidth capacity of the base stations. Besides, the results of the comparative analysis of the handover process in networks based on the WiMAX technology that are obtained using the OpNet simulation environment are presented. Conclusions.The suggested approach can be used to improve the basic software of mobile communication networks. When moving a node from one area to another one in access servers, the

HCI Lessons From PlayStation VR

OpenAIRE

Habgood, Jacob; Wilson, David; Moore, David; Alapont, Sergio

2017-01-01

PlayStation VR has quickly built up a significant user-base of over a million headsets and its own ecosystem of games across a variety of genres. These games form part of a rapidly evolving testing ground for design solutions which can usefully inform HCI design for virtual reality. This paper reviews every PlayStation VR title released in the first three months of its lifecycle in order to identify emerging themes for locomotion. These themes are discussed with respect to the lessons learned...

Benefits of rotational ground motions for planetary seismology

Science.gov (United States)

Donner, S.; Joshi, R.; Hadziioannou, C.; Nunn, C.; van Driel, M.; Schmelzbach, C.; Wassermann, J. M.; Igel, H.

2017-12-01

Exploring the internal structure of planetary objects is fundamental to understand the evolution of our solar system. In contrast to Earth, planetary seismology is hampered by the limited number of stations available, often just a single one. Classic seismology is based on the measurement of three components of translational ground motion. Its methods are mainly developed for a larger number of available stations. Therefore, the application of classical seismological methods to other planets is very limited. Here, we show that the additional measurement of three components of rotational ground motion could substantially improve the situation. From sparse or single station networks measuring translational and rotational ground motions it is possible to obtain additional information on structure and source. This includes direct information on local subsurface seismic velocities, separation of seismic phases, propagation direction of seismic energy, crustal scattering properties, as well as moment tensor source parameters for regional sources. The potential of this methodology will be highlighted through synthetic forward and inverse modeling experiments.

Ground-based multi-station spectroscopic imaging with ALIS. - Scientific highlights, project status and future prospects

Science.gov (United States)

Brändström; Gustavsson, Björn; Pellinen-Wannberg, Asta; Sandahl, Ingrid; Sergienko, Tima; Steen, Ake

2005-08-01

The Auroral Large Imaging System (ALIS) was first proposed at the ESA-PAC meeting in Lahnstein 1989. The first spectroscopic imaging station was operational in 1994, and since then up to six stations have been in simultaneous operation. Each station has a scientific-grade CCD-detector and a filter-wheel for narrow-band interference-filters with six positions. The field-of-view is around 70°. Each imager is mounted in a positioning system, enabling imaging of a common volume from several sites. This enables triangulation and tomography. Raw data from ALIS is freely available at ("http://alis.irf.se") and ALIS is open for scientific colaboration. ALIS made the first unambiguous observations of Radio-induced optical emissions at high latitudes, and the detection of water in a Leonid meteor-trail. Both rockets and satellite coordination are considered for future observations with ALIS.

Perception of mobile phone and base station risks.

Science.gov (United States)

Siegrist, Michael; Earle, Timothy C; Gutscher, Heinz; Keller, Carmen

2005-10-01

Perceptions of risks associated with mobile phones, base stations, and other sources of electromagnetic fields (EMF) were examined. Data from a telephone survey conducted in the German- and French-speaking parts of Switzerland are presented (N = 1,015). Participants assessed both risks and benefits associated with nine different sources of EMF. Trust in the authorities regulating these hazards was assessed as well. In addition, participants answered a set of questions related to attitudes toward EMF and toward mobile phone base stations. According to respondents' assessments, high-voltage transmission lines are the most risky source of EMF. Mobile phones and mobile phone base stations received lower risk ratings. Results showed that trust in authorities was positively associated with perceived benefits and negatively associated with perceived risks. People who use their mobile phones frequently perceived lower risks and higher benefits than people who use their mobile phones infrequently. People who believed they lived close to a base station did not significantly differ in their level of risks associated with mobile phone base stations from people who did not believe they lived close to a base station. Regarding risk regulation, a majority of participants were in favor of fixing limiting values based on the worst-case scenario. Correlations suggest that belief in paranormal phenomena is related to level of perceived risks associated with EMF. Furthermore, people who believed that most chemical substances cause cancer also worried more about EMF than people who did not believe that chemical substances are that harmful. Practical implications of the results are discussed.

Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

KAUST Repository

Nath, Sankar Kumar; Thingbaijam, Kiran Kumar; Adhikari, M. D.; Nayak, Avinash; Devaraj, N.; Ghosh, Soumalya K.; Mahajan, Arun K.

2013-01-01

We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

KAUST Repository

Nath, Sankar Kumar

2013-12-01

We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

Theoretical evaluation of electromagnetic emissions from GSM900 mobile telephony base stations in the West Bank and Gaza Strip-Palestine

International Nuclear Information System (INIS)

Lahham, Adnan; Abu Alkbash, Jehad; ALMasri, Hussien

2017-01-01

Theoretical assessments of power density in far-field conditions were used to evaluate the levels of environmental electromagnetic frequencies from selected GSM900 macrocell base stations in the West Bank and Gaza Strip. Assessments were based on calculating the power densities using commercially available software (RF-Map from Telstra Research Laboratories-Australia). Calculations were carried out for single base stations with multi-antenna systems and also for multiple base stations with multi-antenna systems at 1.7 m above the ground level. More than 100 power density levels were calculated at different locations around the investigated base stations. These locations include areas accessible to the general public (schools, parks, residential areas, streets and areas around kindergartens). The maximum calculated electromagnetic emission level resulted from a single site was 0.413 μW cm -2 and found at Hizma town near Jerusalem. Average maximum power density from all single sites was 0.16 μW cm -2 . The results of all calculated power density levels in 100 locations distributed over the West Bank and Gaza were nearly normally distributed with a peak value of ∼0.01% of the International Commission on Non-Ionizing Radiation Protection's limit recommended for general public. Comparison between calculated and experimentally measured value of maximum power density from a base station showed that calculations overestimate the actual measured power density by ∼27%. (authors)

Ground-based measurement of column-averaged mixing ratios of methane and carbon dioxide in the Sichuan Basin of China by a desktop optical spectrum analyzer

Science.gov (United States)

Qin, Xiu-Chun; Nakayama, Tomoki; Matsumi, Yutaka; Kawasaki, Masahiro; Ono, Akiko; Hayashida, Sachiko; Imasu, Ryoichi; Lei, Li-Ping; Murata, Isao; Kuroki, Takahiro; Ohashi, Masafumi

2018-01-01

Remote sensing of the atmospheric greenhouse gases, methane (CH4) and carbon dioxide (CO2), contributes to the understanding of global warming and climate change. A portable ground-based instrument consisting of a commercially available desktop optical spectrum analyzer and a small sun tracker has been applied to measure the column densities of atmospheric CH4 and CO2 at Yanting observation station in a mountainous paddy field of the Sichuan Basin from September to November 2013. The column-averaged dry-air molar mixing ratios, XCH4/XCO2, are compared with those retrieved by satellite observations in the Sichuan Basin and by ground-based network observations in the same latitude zone as the Yanting observation station.

Ecological Aspects of Condition of Ground Deposits in Shershnevsky Reservoir

Science.gov (United States)

Arkanova, I. A.; Denisov, S. E.; Knutarev, D. Yu

2017-11-01

The article considers the aspects of the condition of ground deposits influencing the operating conditions of the water intake facilities in the Shershnevsky reservoir being the only source of the utility and drinking water supply in Chelyabinsk. The object of the research is a section near the Sosnovskie intake stations of the Shershnevsky reservoir. Based on the hydrometric surveys of the studied section and using the Kriging method and the Surfer suite, we calculated the volume of ground deposits. As a result of the analyses, the authors have proved that ground deposits in the studied section have a technology-related nature which is connected with the annual growth of the volume of ground deposits which is inadmissible in the operating conditions of the pump stations of water intake facilities whereas ground deposits will fully block the intake windows of pump stations. In case the bed area of the Shershnevsky reservoir is not timely treated, the ground deposits here will complicate the operation of the pump stations which will result in a technological problem of the treatment facilities operation up to a transfer of the pump station premises to other territories less exposed to the deposits. The treatment of the Shershnevsky reservoir from the ground deposits accumulated in the course of time will help to considerably increase its actual capacity, which will allow one to increase water circulation paths and to improve the water quality indices. In its turn, the water quality improvement will decrease the supply of suspended solids into the water intake facilities and cut the reagent costs in the course of the treatment water works operation.

Ground-based Observations for the Upper Atmosphere at King Sejong Station, Antarctica

Science.gov (United States)

Jee, Geonhwa; Kim, Jeong-Han; Lee, Changsup; Kim, Yong Ha

2014-06-01

Since the operation of the King Sejong Station (KSS) started in Antarctic Peninsula in 1989, there have been continuous efforts to perform the observation for the upper atmosphere. The observations during the initial period of the station include Fabry-Perot Interferometer (FPI) and Michelson Interferometer for the mesosphere and thermosphere, which are no longer in operation. In 2002, in collaboration with York University, Canada, the Spectral Airglow Temperature Imager (SATI) was installed to observe the temperature in the mesosphere and lower thermosphere (MLT) region and it has still been producing the mesopause temperature data until present. The observation was extended by installing the meteor radar in 2007 to observe the neutral winds and temperature in the MLT region during the day and night in collaboration with Chungnam National University. We also installed the all sky camera in 2008 to observe the wave structures in the MLT region. All these observations are utilized to study on the physical characteristics of the MLT region and also on the wave phenomena such as the tide and gravity wave in the upper atmosphere over KSS that is well known for the strong gravity wave activity. In this article, brief introductions for the currently operating instruments at KSS will be presented with their applications for the study of the upper atmosphere

Ground-based Observations for the Upper Atmosphere at King Sejong Station, Antarctica

Directory of Open Access Journals (Sweden)

Geonhwa Jee

2014-06-01

Full Text Available Since the operation of the King Sejong Station (KSS started in Antarctic Peninsula in 1989, there have been continuous efforts to perform the observation for the upper atmosphere. The observations during the initial period of the station include Fabry-Perot Interferometer (FPI and Michelson Interferometer for the mesosphere and thermosphere, which are no longer in operation. In 2002, in collaboration with York University, Canada, the Spectral Airglow Temperature Imager (SATI was installed to observe the temperature in the mesosphere and lower thermosphere (MLT region and it has still been producing the mesopause temperature data until present. The observation was extended by installing the meteor radar in 2007 to observe the neutral winds and temperature in the MLT region during the day and night in collaboration with Chungnam National University. We also installed the all sky camera in 2008 to observe the wave structures in the MLT region. All these observations are utilized to study on the physical characteristics of the MLT region and also on the wave phenomena such as the tide and gravity wave in the upper atmosphere over KSS that is well known for the strong gravity wave activity. In this article, brief introductions for the currently operating instruments at KSS will be presented with their applications for the study of the upper atmosphere.

Theoretical Evaluation of Electromagnetic Emissions from GSM900 Mobile Telephony Base Stations in the West Bank and Gaza Strip-Palestine.

Science.gov (United States)

Lahham, Adnan; Alkbash, Jehad Abu; ALMasri, Hussien

2017-04-20

Theoretical assessments of power density in far-field conditions were used to evaluate the levels of environmental electromagnetic frequencies from selected GSM900 macrocell base stations in the West Bank and Gaza Strip. Assessments were based on calculating the power densities using commercially available software (RF-Map from Telstra Research Laboratories-Australia). Calculations were carried out for single base stations with multiantenna systems and also for multiple base stations with multiantenna systems at 1.7 m above the ground level. More than 100 power density levels were calculated at different locations around the investigated base stations. These locations include areas accessible to the general public (schools, parks, residential areas, streets and areas around kindergartens). The maximum calculated electromagnetic emission level resulted from a single site was 0.413 μW cm-2 and found at Hizma town near Jerusalem. Average maximum power density from all single sites was 0.16 μW cm-2. The results of all calculated power density levels in 100 locations distributed over the West Bank and Gaza were nearly normally distributed with a peak value of ~0.01% of the International Commission on Non-Ionizing Radiation Protection's limit recommended for general public. Comparison between calculated and experimentally measured value of maximum power density from a base station showed that calculations overestimate the actual measured power density by ~27%. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Ground based observations of Pc3-Pc5 geomagnetic pulsation power at Antarctic McMurdo station

Directory of Open Access Journals (Sweden)

C. G. Maclennan

1998-06-01

Full Text Available The two horizontal geomagnetic components and, measured by a fluxgate magnetometer at Antarctic McMurdo station (corrected geomagnetic coordinates 80.0° S, 327.5° E, are analyzed for the period May-June 1994; the spectral powers are calculated and integrated over three frequency intervals corresponding to the nominal ranges. The time dependence of those integrated powers and their correlations with northern auroral indices and solar wind speed are considered. The observations are compared with previous results reported from Terra Nova Bay station (located near McMurdo at the same corrected geomagnetic latitude during Antarctic summer intervals. The differences found between the two stations are discussed in terms of the seasonal dependence of geomagnetic field line configurations in the near cusp region.

TANGOO: A ground-based tilting-filter spectrometer for deriving the temperature in the mesopause region

Science.gov (United States)

Wildner, S.; Bittner, M.

2009-04-01

TANGOO (Tilting-filter spectrometer for Atmospheric Nocturnal Ground-based Oxygen & hydrOxyl emission measurements) is a passive, ground-based optical instrument for the purpose of a simultanously automatic long-term monitoring of OH(6-2) and O2 atm. Band (0-1) emissions (called "airglow"), yielding rotational temperatures in about 87 and 95 km, respectively. TANGOO, being a transportable and comparatively easy-to-use instrument, is the enhancement of the Argentine Airglow Spectrometer (Scheer, 1987) and shows significant improvements in the temporal resolution and throughput. It will be located on the German Enviromental Research Station "Schneefernerhaus", Zugspitze (47°,4 N, 11° E) and will start measurements in 2009. Objectives of TANGOO cover the analysis of dynamical processes such as gravity waves as well as the identification of climate signals. The observation method will be presented.

Neurobehavioral effects among inhabitants around mobile phone base stations.

Science.gov (United States)

Abdel-Rassoul, G; El-Fateh, O Abou; Salem, M Abou; Michael, A; Farahat, F; El-Batanouny, M; Salem, E

2007-03-01

There is a general concern on the possible hazardous health effects of exposure to radiofrequency electromagnetic radiations (RFR) emitted from mobile phone base station antennas on the human nervous system. To identify the possible neurobehavioral deficits among inhabitants living nearby mobile phone base stations. A cross-sectional study was conducted on (85) inhabitants living nearby the first mobile phone station antenna in Menoufiya governorate, Egypt, 37 are living in a building under the station antenna while 48 opposite the station. A control group (80) participants were matched with the exposed for age, sex, occupation and educational level. All participants completed a structured questionnaire containing: personal, educational and medical histories; general and neurological examinations; neurobehavioral test battery (NBTB) [involving tests for visuomotor speed, problem solving, attention and memory]; in addition to Eysenck personality questionnaire (EPQ). The prevalence of neuropsychiatric complaints as headache (23.5%), memory changes (28.2%), dizziness (18.8%), tremors (9.4%), depressive symptoms (21.7%), and sleep disturbance (23.5%) were significantly higher among exposed inhabitants than controls: (10%), (5%), (5%), (0%), (8.8%) and (10%), respectively (Pstation exhibited a lower performance in the problem solving test (block design) than those under the station. All inhabitants exhibited a better performance in the two tests of visuomotor speed (Digit symbol and Trailmaking B) and one test of attention (Trailmaking A) than controls. The last available measures of RFR emitted from the first mobile phone base station antennas in Menoufiya governorate were less than the allowable standard level. Inhabitants living nearby mobile phone base stations are at risk for developing neuropsychiatric problems and some changes in the performance of neurobehavioral functions either by facilitation or inhibition. So, revision of standard guidelines for public

Exposure to electromagnetic radiation from GSM and UMTS base station antennas

International Nuclear Information System (INIS)

Oliveira, C.; Carpinteiro, G.; Correia, L.M.

2003-01-01

This paper discusses processes for measurement of GSM and UMTS signal strength on different scenarios, regarding base stations compliance evaluation with radiation exposure limits. Recommendations to minimize exposure from base station antennas' radiation are also established. Propagation models application and their importance to base stations security evaluation are analysed. An application example of the use of these models in a software tool development is given. A measurement campaign to collect real data from base stations in Lisbon is described, and propagation models applicability is discussed. Radiation reference levels were never exceeded on the analysed base stations. The worst-case detected was about five time (in terms of electric field strength) below security limits adopted by the European Union Council. Nevertheless, in general, the measured stations were at least thirteen times below limits. Scenarios where differences between measurements and limits are lower and exposure on buildings' rooftops with base stations and indoors. (author)

Mobile phone base stations-Effects on wellbeing and health.

Science.gov (United States)

Kundi, Michael; Hutter, Hans-Peter

2009-08-01

Studying effects of mobile phone base station signals on health have been discouraged by authoritative bodies like WHO International EMF Project and COST 281. WHO recommended studies around base stations in 2003 but again stated in 2006 that studies on cancer in relation to base station exposure are of low priority. As a result only few investigations of effects of base station exposure on health and wellbeing exist. Cross-sectional investigations of subjective health as a function of distance or measured field strength, despite differences in methods and robustness of study design, found indications for an effect of exposure that is likely independent of concerns and attributions. Experimental studies applying short-term exposure to base station signals gave various results, but there is weak evidence that UMTS and to a lesser degree GSM signals reduce wellbeing in persons that report to be sensitive to such exposures. Two ecological studies of cancer in the vicinity of base stations report both a strong increase of incidence within a radius of 350 and 400m respectively. Due to the limitations inherent in this design no firm conclusions can be drawn, but the results underline the urgent need for a comprehensive investigation of this issue. Animal and in vitro studies are inconclusive to date. An increased incidence of DMBA induced mammary tumors in rats at a SAR of 1.4W/kg in one experiment could not be replicated in a second trial. Indications of oxidative stress after low-level in vivo exposure of rats could not be supported by in vitro studies of human fibroblasts and glioblastoma cells. From available evidence it is impossible to delineate a threshold below which no effect occurs, however, given the fact that studies reporting low exposure were invariably negative it is suggested that power densities around 0.5-1mW/m(2) must be exceeded in order to observe an effect. The meager data base must be extended in the coming years. The difficulties of investigating

NASA space station automation: AI-based technology review

Science.gov (United States)

Firschein, O.; Georgeff, M. P.; Park, W.; Neumann, P.; Kautz, W. H.; Levitt, K. N.; Rom, R. J.; Poggio, A. A.

1985-01-01

Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures.

Ground-based search for the brightest transiting planets with the Multi-site All-Sky CAmeRA: MASCARA

Science.gov (United States)

Snellen, Ignas A. G.; Stuik, Remko; Navarro, Ramon; Bettonvil, Felix; Kenworthy, Matthew; de Mooij, Ernst; Otten, Gilles; ter Horst, Rik; le Poole, Rudolf

2012-09-01

The Multi-site All-sky CAmeRA MASCARA is an instrument concept consisting of several stations across the globe, with each station containing a battery of low-cost cameras to monitor the near-entire sky at each location. Once all stations have been installed, MASCARA will be able to provide a nearly 24-hr coverage of the complete dark sky, down to magnitude 8, at sub-minute cadence. Its purpose is to find the brightest transiting exoplanet systems, expected in the V=4-8 magnitude range - currently not probed by space- or ground-based surveys. The bright/nearby transiting planet systems, which MASCARA will discover, will be the key targets for detailed planet atmosphere observations. We present studies on the initial design of a MASCARA station, including the camera housing, domes, and computer equipment, and on the photometric stability of low-cost cameras showing that a precision of 0.3-1% per hour can be readily achieved. We plan to roll out the first MASCARA station before the end of 2013. A 5-station MASCARA can within two years discover up to a dozen of the brightest transiting planet systems in the sky.

Prototype Environmental Assessment of the impacts of siting and construction of an SPS ground receiving station

Science.gov (United States)

Hill, J.

1980-01-01

A prototype assessment of the environmental impacts of siting and constructing a Satellite Power System (SPS) Ground Receiving Station (GRS) is reported. The objectives of the study were: (1) to develop an assessment of the nonmicrowave related impacts of the reference system SPS GRS on the natural environment; (2) to assess the impacts of GRS construction and operations in the context of actual baseline data for a site in the California desert; and (3) to identify critical GRS characteristics or parameters that are most significant in terms of the natural environment.

A super base station based centralized network architecture for 5G mobile communication systems

Directory of Open Access Journals (Sweden)

Manli Qian

2015-04-01

Full Text Available To meet the ever increasing mobile data traffic demand, the mobile operators are deploying a heterogeneous network with multiple access technologies and more and more base stations to increase the network coverage and capacity. However, the base stations are isolated from each other, so different types of radio resources and hardware resources cannot be shared and allocated within the overall network in a cooperative way. The mobile operators are thus facing increasing network operational expenses and a high system power consumption. In this paper, a centralized radio access network architecture, referred to as the super base station (super BS, is proposed, as a possible solution for an energy-efficient fifth-generation (5G mobile system. The super base station decouples the logical functions and physical entities of traditional base stations, so different types of system resources can be horizontally shared and statistically multiplexed among all the virtual base stations throughout the entire system. The system framework and main functionalities of the super BS are described. Some key technologies for system implementation, i.e., the resource pooling, real-time virtualization, adaptive hardware resource allocation are also highlighted.

Development of a Ground-Based Atmospheric Monitoring Network for the Global Mercury Observation System (GMOS

Directory of Open Access Journals (Sweden)

Sprovieri F.

2013-04-01

Full Text Available Consistent, high-quality measurements of atmospheric mercury (Hg are necessary in order to better understand Hg emissions, transport, and deposition on a global scale. Although the number of atmospheric Hg monitoring stations has increased in recent years, the available measurement database is limited and there are many regions of the world where measurements have not been extensively performed. Long-term atmospheric Hg monitoring and additional ground-based monitoring sites are needed in order to generate datasets that will offer new insight and information about the global scale trends of atmospheric Hg emissions and deposition. In the framework of the Global Mercury Observation System (GMOS project, a coordinated global observational network for atmospheric Hg is being established. The overall research strategy of GMOS is to develop a state-of-the-art observation system able to provide information on the concentration of Hg species in ambient air and precipitation on the global scale. This network is being developed by integrating previously established ground-based atmospheric Hg monitoring stations with newly established GMOS sites that are located both at high altitude and sea level locations, as well as in climatically diverse regions. Through the collection of consistent, high-quality atmospheric Hg measurement data, we seek to create a comprehensive assessment of atmospheric Hg concentrations and their dependence on meteorology, long-range atmospheric transport and atmospheric emissions.

Performance evaluation of optical channel transmission between UAVs and Ground Stations

Directory of Open Access Journals (Sweden)

Hatziefremidis Antonis

2016-01-01

Full Text Available Free space optical (FSO communications links is a promising solution for the provision of high data rate point to point communications. In particular deploying FSO technology for mobile links between Unmanned Aerial Vehicles (UAVs and fixed Ground Stations (GS introduces several interesting challenges. In this paper, we investigate the ability of a mobile FSO system to operate in different atmospheric conditions. Specifically, we characterize the quality of the optical channel with a proper model in terms of Bit Error Rate (BER and average Signal to Noise Ratio (SNR and we report a detailed optical amplification model able to support a constant Quality of Service for different distances from 1 km up to 35 km at 10 Gbps with 1550 nm wavelength. An extensive comparative analysis among different FSO configurations links considering the altitude of the UAV, the wavelength and the atmospheric conditions is provided. The results show that there is degradation at the BER over a slanted path compared to a horizontal path at the same conditions.

Stratigraphic Profiles for Selected Hanford Site Seismometer Stations and Other Locations

Energy Technology Data Exchange (ETDEWEB)

Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-02-01

Stratigraphic profiles were constructed for eight selected Hanford Site seismometer stations, five Hanford Site facility reference locations, and seven regional three-component broadband seismometer stations. These profiles provide interpretations of the subsurface layers to support estimation of ground motions from past earthquakes, and the prediction of ground motions from future earthquakes. In most cases these profiles terminated at the top of the Wanapum Basalt, but at selected sites profiles were extended down to the top of the crystalline basement. The composite one-dimensional stratigraphic profiles were based primarily on previous interpretations from nearby boreholes, and in many cases the nearest deep borehole is located kilometers away.

Level of Radiofrequency (RF) Radiations from GSM Base Stations ...

African Journals Online (AJOL)

Levels of radiofrequency radiations around two global systems for mobile communication (GSM) base stations located in the vicinity of a residential quarter and workplace complex were measured. The effects of the radiofrequency radiations on albino mice placed in exposure cages and located around the base stations ...

Extended architecture for home base stations with multimedia services

NARCIS (Netherlands)

Voicu, A.; Jarnikov, D.S.

2011-01-01

This paper describes the use of mobile access points (home node base stations, femtocells) for providing TV streaming to mobile devices inside the home. The research is focused on finding commonalities between architectures of the home node base station for different technologies. The result is a

16 year climatology of cirrus clouds over a tropical station in southern India using ground and space-based lidar observations

Science.gov (United States)

Pandit, A. K.; Gadhavi, H. S.; Venkat Ratnam, M.; Raghunath, K.; Rao, S. V. B.; Jayaraman, A.

2015-06-01

16 year (1998-2013) climatology of cirrus clouds and their macrophysical (base height, top height and geometrical thickness) and optical properties (cloud optical thickness) observed using a ground-based lidar over Gadanki (13.5° N, 79.2° E), India, is presented. The climatology obtained from the ground-based lidar is compared with the climatology obtained from seven and half years (June 2006-December 2013) of Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) observations. A very good agreement is found between the two climatologies in spite of their opposite viewing geometries and difference in sampling frequencies. Nearly 50-55% of cirrus clouds were found to possess geometrical thickness less than 2 km. Ground-based lidar is found to detect more number of sub-visible clouds than CALIOP which has implications for global warming studies as sub-visible cirrus clouds have significant positive radiative forcing. Cirrus clouds with mid-cloud temperatures between -50 to -70 °C have a mean geometrical thickness greater than 2 km in contrast to the earlier reported value of 1.7 km. Trend analyses reveal a statistically significant increase in the altitude of sub-visible cirrus clouds which is consistent with the recent climate model simulations. Also, the fraction of sub-visible cirrus cloud is found to be increasing during the last sixteen years (1998 to 2013) which has implications to the temperature and water vapour budget in the tropical tropopause layer.

Epidemiological evidence for a health risk from mobile phone base stations.

Science.gov (United States)

Khurana, Vini G; Hardell, Lennart; Everaert, Joris; Bortkiewicz, Alicja; Carlberg, Michael; Ahonen, Mikko

2010-01-01

Human populations are increasingly exposed to microwave/radiofrequency (RF) emissions from wireless communication technology, including mobile phones and their base stations. By searching PubMed, we identified a total of 10 epidemiological studies that assessed for putative health effects of mobile phone base stations. Seven of these studies explored the association between base station proximity and neurobehavioral effects and three investigated cancer. We found that eight of the 10 studies reported increased prevalence of adverse neurobehavioral symptoms or cancer in populations living at distances base stations. None of the studies reported exposure above accepted international guidelines, suggesting that current guidelines may be inadequate in protecting the health of human populations. We believe that comprehensive epidemiological studies of long-term mobile phone base station exposure are urgently required to more definitively understand its health impact.

On increasing the spectral efficiency and transmissivity in the data transmission channel on the spacecraft-ground tracking station line

Science.gov (United States)

Andrianov, M. N.; Kostenko, V. I.; Likhachev, S. F.

2018-01-01

The algorithms for achieving a practical increase in the rate of data transmission on the space-craft-ground tracking station line has been considered. This increase is achieved by applying spectral-effective modulation techniques, the technology of orthogonal frequency compression of signals using millimeterrange radio waves. The advantages and disadvantages of each of three algorithms have been revealed. A significant advantage of data transmission in the millimeter range has been indicated.

Data Distribution System (DDS) and Solar Dynamic Observatory Ground Station (SDOGS) Integration Manager

Science.gov (United States)

Pham, Kim; Bialas, Thomas

2012-01-01

The DDS SDOGS Integration Manager (DSIM) provides translation between native control and status formats for systems within DDS and SDOGS, and the ASIST (Advanced Spacecraft Integration and System Test) control environment in the SDO MOC (Solar Dynamics Observatory Mission Operations Center). This system was created in response for a need to centralize remote monitor and control of SDO Ground Station equipments using ASIST control environment in SDO MOC, and to have configurable table definition for equipment. It provides translation of status and monitoring information from the native systems into ASIST-readable format to display on pages in the MOC. The manager is lightweight, user friendly, and efficient. It allows data trending, correlation, and storing. It allows using ASIST as common interface for remote monitor and control of heterogeneous equipments. It also provides failover capability to back up machines.

Ground-water discharge and base-flow nitrate loads of nontidal streams, and their relation to a hydrogeomorphic classification of the Chesapeake Bay Watershed, middle Atlantic Coast

Science.gov (United States)

Bachman, L. Joseph; Lindsey, Bruce D.; Brakebill, John W.; Powars, David S.

1998-01-01

Existing data on base-flow and groundwater nitrate loads were compiled and analyzed to assess the significance of groundwater discharge as a source of the nitrate load to nontidal streams of the Chesapeake Bay watershed. These estimates were then related to hydrogeomorphic settings based on lithology and physiographic province to provide insight on the areal distribution of ground-water discharge. Base-flow nitrate load accounted for 26 to about 100 percent of total-flow nitrate load, with a median value of 56 percent, and it accounted for 17 to 80 percent of total-flow total-nitrogen load, with a median value of 48 percent. Hydrograph separations were conducted on continuous streamflow records from 276 gaging stations within the watershed. The values for base flow thus calculated were considered an estimate of ground-water discharge. The ratio of base flow to total flow provided an estimate of the relative importance of ground-water discharge within a basin. Base-flow nitrate loads, total-flow nitrate loads, and total-flow total-nitrogen loads were previously computed from water-quality and discharge measurements by use of a regression model. Base-flow nitrate loads were available from 78 stations, total-flow nitrate loads were available from 86 stations, and total-flow total-nitrogen loads were available for 48 stations. The percentage of base-flow nitrate load to total-flow nitrate load could be computed for 57 stations, whereas the percentage of base-flow nitrate load to totalflow total-nitrogen load could be computed for 36 stations. These loads were divided by the basin area to obtain yields, which were used to compare the nitrate discharge from basins of different sizes. The results indicate that ground-water discharge is a significant source of water and nitrate to the total streamflow and nitrate load. Base flow accounted for 16 to 92 percent of total streamflow at the 276 sampling sites, with a median value of 54 percent. It is estimated that of the 50

Ground-based observations of exoplanet atmospheres

NARCIS (Netherlands)

Mooij, Ernst Johan Walter de

2011-01-01

This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

Space station accommodations for lunar base elements: A study

Science.gov (United States)

Weidman, Deene J.; Cirillo, William; Llewellyn, Charles; Kaszubowski, Martin; Kienlen, E. Michael, Jr.

1987-01-01

The results of a study conducted at NASA-LaRC to assess the impact on the space station of accommodating a Manned Lunar Base are documented. Included in the study are assembly activities for all infrastructure components, resupply and operations support for lunar base elements, crew activity requirements, the effect of lunar activities on Cape Kennedy operations, and the effect on space station science missions. Technology needs to prepare for such missions are also defined. Results of the study indicate that the space station can support the manned lunar base missions with the addition of a Fuel Depot Facility and a heavy lift launch vehicle to support the large launch requirements.

Immune System Dysregulation and Latent Herpesvirus Reactivation During Winterover at Concordia Station, Dome C, Antarctica

Science.gov (United States)

Crucian, B. E.; Feuerecker, M.; Salam, A. P.; Rybka, A.; Stowe, R. P.; Morrels, M.; Meta, S. K.; Quiriarte, H.; Quintens, Roel; Thieme, U.;

Ionospheric turbulence from ground-based and satellite VLF/LF transmitter signal observations for the Simushir earthquake (November 15, 2006

Directory of Open Access Journals (Sweden)

Pier Francesco Biagi

2012-04-01

Full Text Available

Signals from very low frequency (VLF/ low frequency (LF transmitters recorded on the ground station at Petropavlovsk-Kamchatsky and on board the French DEMETER satellite were analyzed for the Simushir earthquake (M 8.3; November 15, 2006. The period of analysis was from October 1, 2006, to January 31, 2007. The ground and satellite data were processed by a method based on the difference between the real signal at night-time and the model signal. The model for the ground observations was the monthly averaged signal amplitudes and phases, as calculated for the quiet days of every month. For the satellite data, a two-dimensional model of the signal distribution over the selected area was constructed. Preseismic effects were found several days before the earthquake, in both the ground and satellite observations.

Quantum key distribution using card, base station and trusted authority

Energy Technology Data Exchange (ETDEWEB)

Nordholt, Jane E.; Hughes, Richard John; Newell, Raymond Thorson; Peterson, Charles Glen; Rosenberg, Danna; McCabe, Kevin Peter; Tyagi, Kush T.; Dallmann, Nicholas

2017-06-14

Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trust authority. The keys can be used to set up secure communication, for authentication, for access control, or for other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.

Quantum key distribution using card, base station and trusted authority

Science.gov (United States)

Nordholt, Jane Elizabeth; Hughes, Richard John; Newell, Raymond Thorson; Peterson, Charles Glen; Rosenberg, Danna; McCabe, Kevin Peter; Tyagi, Kush T; Dallman, Nicholas

2015-04-07

Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trusted authority. The keys can be used to set up secure communication, for authentication, for access control, or for other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.

Comparisons between ground-based FTIR and MIPAS N2O and HNO3 profiles before and after assimilation in BASCOE

Directory of Open Access Journals (Sweden)

C. Vigouroux

2007-01-01

Full Text Available Within the framework of the Network for Detection of Atmospheric Composition Change (NDACC, regular ground-based Fourier transform infrared (FTIR measurements of many species are performed at several locations. Inversion schemes provide vertical profile information and characterization of the retrieved products which are therefore relevant for contributing to the validation of MIPAS profiles in the stratosphere and upper troposphere. We have focused on the species HNO3 and N2O at 5 NDACC-sites distributed in both hemispheres, i.e., Jungfraujoch (46.5° N and Kiruna (68° N for the northern hemisphere, and Wollongong (34° S, Lauder (45° S and Arrival Heights (78° S for the southern hemisphere. These ground-based data have been compared with MIPAS offline profiles (v4.61 for the year 2003, collocated within 1000 km around the stations, in the lower to middle stratosphere. To get around the spatial collocation problem, comparisons have also been made between the same ground-based FTIR data and the corresponding profiles resulting from the stratospheric 4D-VAR data assimilation system BASCOE constrained by MIPAS data. This paper discusses the results of the comparisons and the usefullness of using BASCOE profiles as proxies for MIPAS data. It shows good agreement between MIPAS and FTIR N2O partial columns: the biases are below 5% for all the stations and the standard deviations are below 7% for the three mid-latitude stations, and below 10% for the high latitude ones. The comparisons with BASCOE partial columns give standard deviations below 4% for the mid-latitude stations to less than 8% for the high latitude ones. After making some corrections to take into account the known bias due to the use of different spectroscopic parameters, the comparisons of HNO3 partial columns show biases below 3% and standard deviations below 15% for all the stations except Arrival Heights (bias of 5%, standard deviation of 21%. The results for this species, which

DMA Reference Base Station Network Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The data (15,904 records documenting 9,090 worldwide gravity base stations) were gathered by various governmental organizations (and academia) using a variety of...

Development and verification of ground-based tele-robotics operations concept for Dextre

Science.gov (United States)

Aziz, Sarmad

2013-05-01

The Special Purpose Dextreous Manipulator (Dextre) is the latest addition to the on-orbit segment of the Mobile Servicing System (MSS); Canada's contribution to the International Space Station (ISS). Launched in March 2008, the advanced two-armed robot is designed to perform various ISS maintenance tasks on robotically compatible elements and on-orbit replaceable units using a wide variety of tools and interfaces. The addition of Dextre has increased the capabilities of the MSS, and has introduced significant complexity to ISS robotics operations. While the initial operations concept for Dextre was based on human-in-the-loop control by the on-orbit astronauts, the complexities of robotic maintenance and the associated costs of training and maintaining the operator skills required for Dextre operations demanded a reexamination of the old concepts. A new approach to ISS robotic maintenance was developed in order to utilize the capabilities of Dextre safely and efficiently, while at the same time reducing the costs of on-orbit operations. This paper will describe the development, validation, and on-orbit demonstration of the operations concept for ground-based tele-robotics control of Dextre. It will describe the evolution of the new concepts from the experience gained from the development and implementation of the ground control capability for the Space Station Remote Manipulator System; Canadarm 2. It will discuss the various technical challenges faced during the development effort, such as requirements for high positioning accuracy, force/moment sensing and accommodation, failure tolerance, complex tool operations, and the novel operational tools and techniques developed to overcome them. The paper will also describe the work performed to validate the new concepts on orbit and will discuss the results and lessons learned from the on-orbit checkout and commissioning of Dextre using the newly developed tele-robotics techniques and capabilities.

OMI and Ground-Based In-Situ Tropospheric Nitrogen Dioxide Observations over Several Important European Cities during 2005–2014

Directory of Open Access Journals (Sweden)

Spiru Paraschiv

2017-11-01

Full Text Available In this work we present the evolution of tropospheric nitrogen dioxide (NO2 content over several important European cities during 2005–2014 using space observations and ground-based in-situ measurements. The NO2 content was derived using the daily observations provided by the Ozone Monitoring Instrument (OMI, while the NO2 volume mixing ratio measurements were obtained from the European Environment Agency (EEA air quality monitoring stations database. The European cities selected are: Athens (37.98° N, 23.72° E, Berlin (52.51° N, 13.41° E, Bucharest (44.43° N, 26.10° E, Madrid (40.38° N, 3.71° W, Lisbon (38.71° N, 9.13° W, Paris (48.85° N, 2.35° E, Rome (41.9° N, 12.50° E, and Rotterdam (51.91° N, 4.46° E. We show that OMI NO2 tropospheric column data can be used to assess the evolution of NO2 over important European cities. According to the statistical analysis, using the seasonal variation, we found good correlations (R > 0.50 between OMI and ground-based in-situ observations for all of the cities presented in this work. Highest correlation coefficients (R > 0.80 between ground-based monitoring stations and OMI observations were calculated for the cities of Berlin, Madrid, and Rome. Both types of observations, in-situ and remote sensing, show an NO2 negative trend for all of locations presented in this study.

Comparative international analysis of radiofrequency exposure surveys of mobile communication radio base stations

Science.gov (United States)

Rowley, Jack T; Joyner, Ken H

2012-01-01

This paper presents analyses of data from surveys of radio base stations in 23 countries across five continents from the year 2000 onward and includes over 173,000 individual data points. The research compared the results of the national surveys, investigated chronological trends and compared exposures by technology. The key findings from this data are that irrespective of country, the year and cellular technology, exposures to radio signals at ground level were only a small fraction of the relevant human exposure standards. Importantly, there has been no significant increase in exposure levels since the widespread introduction of 3G mobile services, which should be reassuring for policy makers and negate the need for post-installation measurements at ground level for compliance purposes. There may be areas close to antennas where compliance levels could be exceeded. Future potential work includes extending the study to additional countries, development of cumulative exposure distributions and investigating the possibility of linking exposure measurements to population statistics to assess the distribution of exposure levels relative to population percentiles. PMID:22377680

Comparative international analysis of radiofrequency exposure surveys of mobile communication radio base stations.

Science.gov (United States)

Rowley, Jack T; Joyner, Ken H

2012-01-01

This paper presents analyses of data from surveys of radio base stations in 23 countries across five continents from the year 2000 onward and includes over 173,000 individual data points. The research compared the results of the national surveys, investigated chronological trends and compared exposures by technology. The key findings from this data are that irrespective of country, the year and cellular technology, exposures to radio signals at ground level were only a small fraction of the relevant human exposure standards. Importantly, there has been no significant increase in exposure levels since the widespread introduction of 3G mobile services, which should be reassuring for policy makers and negate the need for post-installation measurements at ground level for compliance purposes. There may be areas close to antennas where compliance levels could be exceeded. Future potential work includes extending the study to additional countries, development of cumulative exposure distributions and investigating the possibility of linking exposure measurements to population statistics to assess the distribution of exposure levels relative to population percentiles.

Are people living next to mobile phone base stations more strained? Relationship of health concerns, self-estimated distance to base station, and psychological parameters.

Science.gov (United States)

Augner, Christoph; Hacker, Gerhard W

2009-12-01

Coeval with the expansion of mobile phone technology and the associated obvious presence of mobile phone base stations, some people living close to these masts reported symptoms they attributed to electromagnetic fields (EMF). Public and scientific discussions arose with regard to whether these symptoms were due to EMF or were nocebo effects. The aim of this study was to find out if people who believe that they live close to base stations show psychological or psychobiological differences that would indicate more strain or stress. Furthermore, we wanted to detect the relevant connections linking self-estimated distance between home and the next mobile phone base station (DBS), daily use of mobile phone (MPU), EMF-health concerns, electromagnetic hypersensitivity, and psychological strain parameters. Fifty-seven participants completed standardized and non-standardized questionnaires that focused on the relevant parameters. In addition, saliva samples were used as an indication to determine the psychobiological strain by concentration of alpha-amylase, cortisol, immunoglobulin A (IgA), and substance P. Self-declared base station neighbors (DBS base station neighbors are more strained than others. EMF-related health concerns cannot explain these findings. Further research should identify if actual EMF exposure or other factors are responsible for these results.

Bayesian hierarchical model for variations in earthquake peak ground acceleration within small-aperture arrays

KAUST Repository

Rahpeyma, Sahar

2018-04-17

Knowledge of the characteristics of earthquake ground motion is fundamental for earthquake hazard assessments. Over small distances, relative to the source–site distance, where uniform site conditions are expected, the ground motion variability is also expected to be insignificant. However, despite being located on what has been characterized as a uniform lava‐rock site condition, considerable peak ground acceleration (PGA) variations were observed on stations of a small‐aperture array (covering approximately 1 km2) of accelerographs in Southwest Iceland during the Ölfus earthquake of magnitude 6.3 on May 29, 2008 and its sequence of aftershocks. We propose a novel Bayesian hierarchical model for the PGA variations accounting separately for earthquake event effects, station effects, and event‐station effects. An efficient posterior inference scheme based on Markov chain Monte Carlo (MCMC) simulations is proposed for the new model. The variance of the station effect is certainly different from zero according to the posterior density, indicating that individual station effects are different from one another. The Bayesian hierarchical model thus captures the observed PGA variations and quantifies to what extent the source and recording sites contribute to the overall variation in ground motions over relatively small distances on the lava‐rock site condition.

Bayesian hierarchical model for variations in earthquake peak ground acceleration within small-aperture arrays

KAUST Repository

Rahpeyma, Sahar; Halldorsson, Benedikt; Hrafnkelsson, Birgir; Jonsson, Sigurjon

2018-01-01

Knowledge of the characteristics of earthquake ground motion is fundamental for earthquake hazard assessments. Over small distances, relative to the source–site distance, where uniform site conditions are expected, the ground motion variability is also expected to be insignificant. However, despite being located on what has been characterized as a uniform lava‐rock site condition, considerable peak ground acceleration (PGA) variations were observed on stations of a small‐aperture array (covering approximately 1 km2) of accelerographs in Southwest Iceland during the Ölfus earthquake of magnitude 6.3 on May 29, 2008 and its sequence of aftershocks. We propose a novel Bayesian hierarchical model for the PGA variations accounting separately for earthquake event effects, station effects, and event‐station effects. An efficient posterior inference scheme based on Markov chain Monte Carlo (MCMC) simulations is proposed for the new model. The variance of the station effect is certainly different from zero according to the posterior density, indicating that individual station effects are different from one another. The Bayesian hierarchical model thus captures the observed PGA variations and quantifies to what extent the source and recording sites contribute to the overall variation in ground motions over relatively small distances on the lava‐rock site condition.

Empirical Ground Motion Characterization of Induced Seismicity in Alberta and Oklahoma

Science.gov (United States)

Novakovic, M.; Atkinson, G. M.; Assatourians, K.

2017-12-01

We develop empirical ground-motion prediction equations (GMPEs) for ground motions from induced earthquakes in Alberta and Oklahoma following the stochastic-model-based method of Atkinson et al. (2015 BSSA). The Oklahoma ground-motion database is compiled from over 13,000 small to moderate seismic events (M 1 to 5.8) recorded at 1600 seismic stations, at distances from 1 to 750 km. The Alberta database is compiled from over 200 small to moderate seismic events (M 1 to 4.2) recorded at 50 regional stations, at distances from 30 to 500 km. A generalized inversion is used to solve for regional source, attenuation and site parameters. The obtained parameters describe the regional attenuation, stress parameter and site amplification. Resolving these parameters allows for the derivation of regionally-calibrated GMPEs that can be used to compare ground motion observations between waste water injection (Oklahoma) and hydraulic fracture induced events (Alberta), and further compare induced observations with ground motions resulting from natural sources (California, NGAWest2). The derived GMPEs have applications for the evaluation of hazards from induced seismicity and can be used to track amplitudes across the regions in real time, which is useful for ground-motion-based alerting systems and traffic light protocols.

Methane Emissions from Bangladesh: Bridging the Gap Between Ground-based and Space-borne Estimates

Science.gov (United States)

Peters, C.; Bennartz, R.; Hornberger, G. M.

2015-12-01

Gaining an understanding of methane (CH4) emission sources and atmospheric dispersion is an essential part of climate change research. Large-scale and global studies often rely on satellite observations of column CH4 mixing ratio whereas high-spatial resolution estimates rely on ground-based measurements. Extrapolation of ground-based measurements on, for example, rice paddies to broad region scales is highly uncertain because of spatio-temporal variability. We explore the use of ground-based river stage measurements and independent satellite observations of flooded area along with satellite measurements of CH4 mixing ratio to estimate the extent of methane emissions. Bangladesh, which comprises most of the Ganges Brahmaputra Meghna (GBM) delta, is a region of particular interest for studying spatio-temporal variation of methane emissions due to (1) broadscale rice cultivation and (2) seasonal flooding and atmospheric convection during the monsoon. Bangladesh and its deltaic landscape exhibit a broad range of environmental, economic, and social circumstances that are relevant to many nations in South and Southeast Asia. We explore the seasonal enhancement of CH4 in Bangladesh using passive remote sensing spectrometer CH4 products from the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) and the Atmospheric Infrared Sounder (AIRS). The seasonal variation of CH4 is compared to independent estimates of seasonal flooding from water gauge stations and space-based passive microwave water-to-land fractions from the Tropical Rainfall Measuring Mission Microwave Imager (TRMM-TMI). Annual cycles in inundation (natural and anthropogenic) and atmospheric CH4 concentrations show highly correlated seasonal signals. NOAA's HYSPLIT model is used to determine atmospheric residence time of ground CH4 fluxes. Using the satellite observations, we can narrow the large uncertainty in extrapolation of ground-based CH4 emission estimates from rice paddies

Radiation safety assessment of mobile telephone base stations

International Nuclear Information System (INIS)

Mohd Yusof Mohd Ali; Mohd Anuar Majid; Mohd Amirul Nizam

2002-01-01

Mobile telephone is fast getting popular among users and in fact it has become one of the fastest selling electronic products in the world. More base stations are expected to be built to meet such high demands and this has caused great concerned among members of the public, especially those living close to the stations, about the potential harmful health effects of radiofrequency (RF) radiation produced by such facilities. A project was initiated by MINT in early 2000 with aims to assess the radiation levels present in the areas around the base stations and to establish baseline data on the pattern and trend of the radiation emission from each different set up of the facilities. This paper highlights some basics facts about mobile telephones and preliminary findings of the project. The assessment has been carried out at 16 base station sites and the results indicate that the radiation levels present around these sites are very low. Their broadband readings vary between below the detection limit of 0.3μWatts/cm 2 to 11 μWatts/cm 2 and they are comparable to normal background radiation present in places away from any base stations. The highest level observed was 1.5% of the exposure limit recommended for members of the public. However, locations at close distance in front of the the antenna can be very serious in term of radiation exposure since the radiation level here can easily exceed the permissible exposure limit for public. Safety precaution needs to be taken when entering these areas and they should be out of bound for members of the public. (Author)

Galvanic coupling effects for module-mounting elements of ground-mounted photovoltaic power station

Directory of Open Access Journals (Sweden)

Pierozynski Boguslaw

2017-12-01

Full Text Available This communication reports on the concerns associated with possible generation of galvanic coupling effects for construction materials that are used to manufacture mounting assemblies for ground-mounted photovoltaic (PV power stations. For this purpose, six macro-corrosion galvanic cells were assembled, including: hot-dip Zn/Magnelis®-coated steel/Al and stainless steel (SS/Al cells. Corrosion experiments involved continuous, ca. three-month exposure of these couplings in 3 wt.% NaCl solution, conducted at room temperature for a stable pH value of around 8. All corrosion cells were subjected to regular assessment of galvanic current-density and potential parameters, where special consideration was given to compare the corrosion behaviour of Zn-coated steel samples with that of Magnelis®-coated electrodes. Characterization of surface condition and elemental composition for examined materials was carried-out by means of SEM and EDX spectroscopy techniques.

Measurements and modelling of base station power consumption under real traffic loads.

Science.gov (United States)

Lorincz, Josip; Garma, Tonko; Petrovic, Goran

2012-01-01

Base stations represent the main contributor to the energy consumption of a mobile cellular network. Since traffic load in mobile networks significantly varies during a working or weekend day, it is important to quantify the influence of these variations on the base station power consumption. Therefore, this paper investigates changes in the instantaneous power consumption of GSM (Global System for Mobile Communications) and UMTS (Universal Mobile Telecommunications System) base stations according to their respective traffic load. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a fully operated base station site. Measurements show the existence of a direct relationship between base station traffic load and power consumption. According to this relationship, we develop a linear power consumption model for base stations of both technologies. This paper also gives an overview of the most important concepts which are being proposed to make cellular networks more energy-efficient.

Measurements and Modelling of Base Station Power Consumption under Real Traffic Loads

Directory of Open Access Journals (Sweden)

Goran Petrovic

2012-03-01

Full Text Available Base stations represent the main contributor to the energy consumption of a mobile cellular network. Since traffic load in mobile networks significantly varies during a working or weekend day, it is important to quantify the influence of these variations on the base station power consumption. Therefore, this paper investigates changes in the instantaneous power consumption of GSM (Global System for Mobile Communications and UMTS (Universal Mobile Telecommunications System base stations according to their respective traffic load. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a fully operated base station site. Measurements show the existence of a direct relationship between base station traffic load and power consumption. According to this relationship, we develop a linear power consumption model for base stations of both technologies. This paper also gives an overview of the most important concepts which are being proposed to make cellular networks more energy-efficient.

Ground-truth aerosol lidar observations: can the Klett solutions obtained from ground and space be equal for the same aerosol case?

International Nuclear Information System (INIS)

Ansmann, Albert

2006-01-01

Upcoming multiyear satellite lidar aerosol observations need strong support by a worldwide ground-truth lidar network. In this context the question arises as to whether the ground stations can deliver the same results as obtained from space when the Klett formalism is applied to elastic backscatter lidar data for the same aerosol case. This question is investigated based on simulations of observed cases of simple and complex aerosol layering. The results show that the differences between spaceborne and ground-based observations can be as large as20% for the backscatter and extinction coefficients and the optimum estimates of the column lidar ratios. In cases with complex aerosol layering, the application of the two-layer approach can lead to similar results (space, ground) and accurate products provided that horizontally homogeneous aerosol conditions are given

Optimal base station placement for wireless sensor networks with successive interference cancellation.

Science.gov (United States)

Shi, Lei; Zhang, Jianjun; Shi, Yi; Ding, Xu; Wei, Zhenchun

2015-01-14

We consider the base station placement problem for wireless sensor networks with successive interference cancellation (SIC) to improve throughput. We build a mathematical model for SIC. Although this model cannot be solved directly, it enables us to identify a necessary condition for SIC on distances from sensor nodes to the base station. Based on this relationship, we propose to divide the feasible region of the base station into small pieces and choose a point within each piece for base station placement. The point with the largest throughput is identified as the solution. The complexity of this algorithm is polynomial. Simulation results show that this algorithm can achieve about 25% improvement compared with the case that the base station is placed at the center of the network coverage area when using SIC.

Validation of CALIPSO space-borne-derived attenuated backscatter coefficient profiles using a ground-based lidar in Athens, Greece

Directory of Open Access Journals (Sweden)

R. E. Mamouri

2009-09-01

Full Text Available We present initial aerosol validation results of the space-borne lidar CALIOP -onboard the CALIPSO satellite- Level 1 attenuated backscatter coefficient profiles, using coincident observations performed with a ground-based lidar in Athens, Greece (37.9° N, 23.6° E. A multi-wavelength ground-based backscatter/Raman lidar system is operating since 2000 at the National Technical University of Athens (NTUA in the framework of the European Aerosol Research LIdar NETwork (EARLINET, the first lidar network for tropospheric aerosol studies on a continental scale. Since July 2006, a total of 40 coincidental aerosol ground-based lidar measurements were performed over Athens during CALIPSO overpasses. The ground-based measurements were performed each time CALIPSO overpasses the station location within a maximum distance of 100 km. The duration of the ground–based lidar measurements was approximately two hours, centred on the satellite overpass time. From the analysis of the ground-based/satellite correlative lidar measurements, a mean bias of the order of 22% for daytime measurements and of 8% for nighttime measurements with respect to the CALIPSO profiles was found for altitudes between 3 and 10 km. The mean bias becomes much larger for altitudes lower that 3 km (of the order of 60% which is attributed to the increase of aerosol horizontal inhomogeneity within the Planetary Boundary Layer, resulting to the observation of possibly different air masses by the two instruments. In cases of aerosol layers underlying Cirrus clouds, comparison results for aerosol tropospheric profiles become worse. This is attributed to the significant multiple scattering effects in Cirrus clouds experienced by CALIPSO which result in an attenuation which is less than that measured by the ground-based lidar.

An aerial radiological survey of the Vermont Yankee Nuclear Power Station and surrounding area, Vernon, Vermont

International Nuclear Information System (INIS)

Reiman, R.; Bluitt, C.M.

1993-10-01

An aerial radiological survey was conducted over the Vermont Yankee Nuclear Power Station in Vernon, Vermont, during the period August 7 through August 17, 1989. The survey was conducted at an altitude of 300 feet (91 meters) over a 65-square-mile (168-square-kilometer) area centered on the power station. The purpose of the survey was to document the terrestrial gamma radiation environment of the Vermont Yankee Power Station and surrounding area. The results of the aerial survey are reported as inferred gamma radiation exposure rates at 1 meter above ground level in the form of a contour map. Outside the plant boundary, exposure rates were found to vary between 6 and 10 microroentgens per hour (μR/h) and were attributed to naturally occurring uranium, thorium, and radioactive potassium gamma emitters. The aerial data were compared to ground-based open-quotes benchmarkclose quotes exposure rate measurements and radionuclide assays of soil samples obtained within the survey boundary. The ground-based measurements were found to be in good agreement with those inferred from the aerial measuring system

An aerial radiological survey of the Yankee Rowe Nuclear Power Station and surrounding area, Rowe, Massachusetts

International Nuclear Information System (INIS)

Boyns, P.K.; Bluitt, C.M.

1993-09-01

An aerial radiological survey was conducted over the Yankee Rowe Nuclear Power Station in Rowe, Massachusetts, during the period August 17--24, 1989. The survey was conducted at an altitude of 300 feet (91 meters) over an 87-square-mile (225-square-kilometer) area centered on the power station. The purpose of the survey was to document the terrestrial gamma radiation environment of the Yankee Rowe Power Station and the surrounding area. The results of the aerial survey are reported as inferred gamma radiation exposure rates at 1 meter above ground level in the form of a contour map. Outside the plant boundary, exposure rates were found to vary between 6 and 10 microroentgens per hour (μR/h) and were attributed to naturally-occurring uranium, thorium, and radioactive potassium gamma emitters. The aerial data were compared to ground-based ''benchmark'' exposure rate measurements and radionuclide assays of soil samples obtained within the survey boundary. The ground-based measurements were found to be in good agreement with those inferred from the aerial measuring system

Relative drifts and stability of satellite and ground-based stratospheric ozone profiles at NDACC lidar stations

Directory of Open Access Journals (Sweden)

P. J. Nair

2012-06-01

Full Text Available The long-term evolution of stratospheric ozone at different stations in the low and mid-latitudes is investigated. The analysis is performed by comparing the collocated profiles of ozone lidars, at the northern mid-latitudes (Meteorological Observatory Hohenpeißenberg, Haute-Provence Observatory, Tsukuba and Table Mountain Facility, tropics (Mauna Loa Observatory and southern mid-latitudes (Lauder, with ozonesondes and space-borne sensors (SBUV(/2, SAGE II, HALOE, UARS MLS and Aura MLS, extracted around the stations. Relative differences are calculated to find biases and temporal drifts in the measurements. All measurement techniques show their best agreement with respect to the lidar at 20–40 km, where the differences and drifts are generally within ±5% and ±0.5% yr⁻¹, respectively, at most stations. In addition, the stability of the long-term ozone observations (lidar, SBUV(/2, SAGE II and HALOE is evaluated by the cross-comparison of each data set. In general, all lidars and SBUV(/2 exhibit near-zero drifts and the comparison between SAGE II and HALOE shows larger, but insignificant drifts. The RMS of the drifts of lidar and SBUV(/2 is 0.22 and 0.27% yr⁻¹, respectively at 20–40 km. The average drifts of the long-term data sets, derived from various comparisons, are less than ±0.3% yr⁻¹ in the 20–40 km altitude at all stations. A combined time series of the relative differences between SAGE II, HALOE and Aura MLS with respect to lidar data at six sites is constructed, to obtain long-term data sets lasting up to 27 years. The relative drifts derived from these combined data are very small, within ±0.2% yr⁻¹.

Adaptive downtilt for cellular base stations

NARCIS (Netherlands)

Mestrom, R.M.C.; Coenen, T.J.; Smolders, A.B.

2012-01-01

Efficiency, reconfigurability, and power consumption are paramount for future communication systems in applications such as cellular handsets, base stations and home networking systems. We present our work in the European PANAMA project which addresses the associated challenges. Our work focuses on

47 CFR 90.1331 - Restrictions on the operation of base and fixed stations.

Science.gov (United States)

2010-10-01

...-3700 MHz Band § 90.1331 Restrictions on the operation of base and fixed stations. (a)(1) Except as provided in paragraph (a)(2) of this section, base and fixed stations may not be located within 150 km of... these stations are available at http://www.fcc.gov/ib/sd/3650/. (2) Base and fixed stations may be...

Antenna unit and radio base station therewith

Science.gov (United States)

Kuwahara, Mikio; Doi, Nobukazu; Suzuki, Toshiro; Ishida, Yuji; Inoue, Takashi; Niida, Sumaru

2007-04-10

Phase and amplitude deviations, which are generated, for example, by cables connecting an array antenna of a CDMA base station and the base station, are calibrated in the baseband. The base station comprises: an antenna apparatus 1; couplers 2; an RF unit 3 that converts a receive signal to a baseband signal, converts a transmit signal to a radio frequency, and performs power control; an A/D converter 4 for converting a receive signal to a digital signal; a receive beam form unit 6 that multiplies the receive signal by semi-fixed weight; a despreader 7 for this signal input; a time-space demodulator 8 for demodulating user data; a despreader 9 for probe signal; a space modulator 14 for user data; a spreader 13 for user signal; a channel combiner 12; a Tx calibrater 11 for controlling calibration of a signal; a D/A converter 10; a unit 16 for calculation of correlation matrix for generating a probe signal used for controlling an Rx calibration system and a TX calibration system; a spreader 17 for probe signal; a power control unit 18; a D/A converter 19; an RF unit 20 for probe signal; an A/D converter 21 for signal from the couplers 2; and a despreader 22.

Data communications method for mobile network in fourth generation communications system, involves delivering decoded data to mobile station from relay station, where mobile station receives data from both relay and base stations

DEFF Research Database (Denmark)

2008-01-01

The method involves utilizing a base station (BS) (100) to transmit data to a relay station (RS) (110) and a mobile station (MS) (120), where the data includes two messages. The BS is utilized to transmit the two messages by utilizing a linear combination method, and the data is received in the RS...

33-Foot-Diameter Space Station Leading to Space Base

Science.gov (United States)

1969-01-01

This picture illustrates a concept of a 33-Foot-Diameter Space Station Leading to a Space Base. In-house work of the Marshall Space Flight Center, as well as a Phase B contract with the McDornel Douglas Astronautics Company, resulted in a preliminary design for a space station in 1969 and l970. The Marshall-McDonnel Douglas approach envisioned the use of two common modules as the core configuration of a 12-man space station. Each common module was 33 feet in diameter and 40 feet in length and provided the building blocks, not only for the space station, but also for a 50-man space base. Coupled together, the two modules would form a four-deck facility: two decks for laboratories and two decks for operations and living quarters. Zero-gravity would be the normal mode of operation, although the station would have an artificial gravity capability. This general-purpose orbital facility was to provide wide-ranging research capabilities. The design of the facility was driven by the need to accommodate a broad spectrum of activities in support of astronomy, astrophysics, aerospace medicine, biology, materials processing, space physics, and space manufacturing. To serve the needs of Earth observations, the station was to be placed in a 242-nautical-mile orbit at a 55-degree inclination. An Intermediate-21 vehicle (comprised of Saturn S-IC and S-II stages) would have launched the station in 1977.

New advanced netted ground based and topside radio diagnostics for Space Weather Program

Science.gov (United States)

Rothkaehl, Hanna; Krankowski, Andrzej; Morawski, Marek; Atamaniuk, Barbara; Zakharenkova, Irina; Cherniak, Iurii

2014-05-01

To give a more detailed and complete understanding of physical plasma processes that govern the solar-terrestrial space, and to develop qualitative and quantitative models of the magnetosphere-ionosphere-thermosphere coupling, it is necessary to design and build the next generation of instruments for space diagnostics and monitoring. Novel ground- based wide-area sensor networks, such as the LOFAR (Low Frequency Array) radar facility, comprising wide band, and vector-sensing radio receivers and multi-spacecraft plasma diagnostics should help solve outstanding problems of space physics and describe long-term environmental changes. The LOw Frequency ARray - LOFAR - is a new fully digital radio telescope designed for frequencies between 30 MHz and 240 MHz located in Europe. The three new LOFAR stations will be installed until summer 2015 in Poland. The LOFAR facilities in Poland will be distributed among three sites: Lazy (East of Krakow), Borowiec near Poznan and Baldy near Olsztyn. All they will be connected via PIONIER dedicated links to Poznan. Each site will host one LOFAR station (96 high-band+96 low-band antennas). They will most time work as a part of European network, however, when less charged, they can operate as a national network The new digital radio frequency analyzer (RFA) on board the low-orbiting RELEC satellite was designed to monitor and investigate the ionospheric plasma properties. This two-point ground-based and topside ionosphere-located space plasma diagnostic can be a useful new tool for monitoring and diagnosing turbulent plasma properties. The RFA on board the RELEC satellite is the first in a series of experiments which is planned to be launched into the near-Earth environment. In order to improve and validate the large scales and small scales ionospheric structures we will used the GPS observations collected at IGS/EPN network employed to reconstruct diurnal variations of TEC using all satellite passes over individual GPS stations and the

NASA space station automation: AI-based technology review. Executive summary

Science.gov (United States)

Firschein, O.; Georgeff, M. P.; Park, W.; Cheeseman, P. C.; Goldberg, J.; Neumann, P.; Kautz, W. H.; Levitt, K. N.; Rom, R. J.; Poggio, A. A.

1985-01-01

Research and Development projects in automation technology for the Space Station are described. Artificial Intelligence (AI) based technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics.

Characteristics of Spectral Responses for a Ground Motion from Mediterranean Earthquake – ZEGHANGHANE Station (6.3Mw in Morocco, and its Influence on the Structures

Directory of Open Access Journals (Sweden)

Ahatri Mohamed

2018-01-01

In this case, we determine the spectral response of the ground motion for ZGH station, and study his influence on the structures as well as make a comparison with the requirements of the Moroccan seismic construction regulations (RPS 2000 revised in 2011.

Aircraft monitoring by the fusion of satellite and ground ADS-B data

Science.gov (United States)

Zhang, Xuan; Zhang, Jingjing; Wu, Shufan; Cheng, Qian; Zhu, Rui

2018-02-01

The Automatic Dependent Surveillance- Broadcast (ADS-B) system is today a standard equipment on civil aircraft, transmitting periodically data packages containing information of key data such as aircraft ID, position, altitude and intention. It is designed for terrestrial based ground station to monitor air traffic flow in certain regions. Space based ADS-B is the idea to place sensitive receivers on board satellites in orbit, which can receive ADS-B packages and relay them the relevant ground stations. The terrestrial ADS-B receiver has been widely applied for airport information system, help monitor and control traffic flow, etc. However, its coverage is strongly limited by sea or mountain conditions. This paper first introduces the CubeSat mission, then discusses the integrated application of ADS-B data received from ground stations and from satellites, analyze their characteristics with statistical results of comparison, and explore the technologies to fuse these two different data resources for an integrated application. The satellite data is based on a Chinese CubeSat, STU-2C, being launched into space on Sept 25th 2015. The ADS-B data received from two different resources have shown a good complementary each other, such as to increase the coverage of space for air traffic, and to monitor the whole space in a better and complete way.

Exposure to radio waves near mobile phone base stations

International Nuclear Information System (INIS)

Mann, S.M.; Cooper, T.G.; Allen, S.G.; Blackwell, R.P.; Lowe, A.J.

2000-01-01

Measurements of power density have been made at 17 sites where people were concerned about their exposure to radio waves from mobile phone base stations and where technical data, including the frequencies and radiated powers, have been obtained from the operators. Based on the technical data, the radiated power from antennas used with macrocellular base stations in the UK appears to range from a few watts to a few tens of watts, with typical maximum powers around 80 W. Calculations based on this power indicate that compliance distances would be expected to be no more than 3.1 m for the NRPB guidelines and no more than 8.4 m for the ICNIRP public guidelines. Microcellular base stations appear to use powers no more than a few watts and would not be expected to require compliance distances in excess of a few tens of centimetres. Power density from the base stations of interest was measured at 118 locations at the 17 sites and these data were compared with calculations assuming an inverse square law dependence of power density upon distance from the antennas. It was found that the calculations overestimated the measured power density by up to four orders of magnitude at locations that were either not exposed to the main beam from antennas, or shielded by building fabric. For all locations and for distances up to 250 m from the base stations, power density at the measurement positions did not show any trend to decrease with increasing distance. The signals from other sources were frequently found to be of similar strength to the signals from the base stations of interest. Spectral measurements were obtained over the 30 MHz to 2.9 GHz range at 73 of the locations so that total exposure to radio signals could be assessed. The geometric mean total exposure arising from all radio signals at the locations considered was 2 millionths of the NRPB investigation level, or 18 millionths of the lower ICNIRP public reference level; however, the data varied over several decades. The

Survey of RF exposure levels from mobile telephone base stations in Australia.

Science.gov (United States)

Henderson, S I; Bangay, M J

2006-01-01

This paper reports the results of an exposure level survey of radiofrequency electromagnetic energy originating from mobile telephone base station antennas. Measurements of CDMA800, GSM900, GSM1800, and 3G(UMTS) signals were performed at distances ranging over 50 to 500 m from 60 base stations in five Australian cities. The exposure levels from these mobile telecommunications base stations were found to be well below the general public exposure limits of the ICNIRP guidelines and the Australian radiofrequency standard (ARPANSA RPS3). The highest recorded level from a single base station was 7.8 x 10(-3) W/m(2), which translates to 0.2% of the general public exposure limit.

Error threshold inference from Global Precipitation Measurement (GPM) satellite rainfall data and interpolated ground-based rainfall measurements in Metro Manila

Science.gov (United States)

Ampil, L. J. Y.; Yao, J. G.; Lagrosas, N.; Lorenzo, G. R. H.; Simpas, J.

2017-12-01

The Global Precipitation Measurement (GPM) mission is a group of satellites that provides global observations of precipitation. Satellite-based observations act as an alternative if ground-based measurements are inadequate or unavailable. Data provided by satellites however must be validated for this data to be reliable and used effectively. In this study, the Integrated Multisatellite Retrievals for GPM (IMERG) Final Run v3 half-hourly product is validated by comparing against interpolated ground measurements derived from sixteen ground stations in Metro Manila. The area considered in this study is the region 14.4° - 14.8° latitude and 120.9° - 121.2° longitude, subdivided into twelve 0.1° x 0.1° grid squares. Satellite data from June 1 - August 31, 2014 with the data aggregated to 1-day temporal resolution are used in this study. The satellite data is directly compared to measurements from individual ground stations to determine the effect of the interpolation by contrast against the comparison of satellite data and interpolated measurements. The comparisons are calculated by taking a fractional root-mean-square error (F-RMSE) between two datasets. The results show that interpolation improves errors compared to using raw station data except during days with very small amounts of rainfall. F-RMSE reaches extreme values of up to 654 without a rainfall threshold. A rainfall threshold is inferred to remove extreme error values and make the distribution of F-RMSE more consistent. Results show that the rainfall threshold varies slightly per month. The threshold for June is inferred to be 0.5 mm, reducing the maximum F-RMSE to 9.78, while the threshold for July and August is inferred to be 0.1 mm, reducing the maximum F-RMSE to 4.8 and 10.7, respectively. The maximum F-RMSE is reduced further as the threshold is increased. Maximum F-RMSE is reduced to 3.06 when a rainfall threshold of 10 mm is applied over the entire duration of JJA. These results indicate that

Understanding the Longitudinal Variability of Equatorial Electrodynamics using integrated Ground- and Space-based Observations

Science.gov (United States)

Yizengaw, E.; Moldwin, M.; Zesta, E.

2015-12-01

The currently funded African Meridian B-Field Education and Research (AMBER) magnetometer array comprises more than thirteen magnetometers stationed globally in the vicinity of geomagnetic equator. One of the main objectives of AMBER network is to understand the longitudinal variability of equatorial electrodynamics as function of local time, magnetic activity, and season. While providing complete meridian observation in the region and filling the largest land-based gap in global magnetometer coverage, the AMBER array addresses two fundamental areas of space physics: first, the processes governing electrodynamics of the equatorial ionosphere as a function of latitude (or L-shell), local time, longitude, magnetic activity, and season, and second, ULF pulsation strength at low/mid-latitude regions and its connection with equatorial electrojet and density fluctuation. The global AMBER network can also be used to augment observations from space-based instruments, such us the triplet SWARM mission and the upcoming ICON missions. Thus, in coordination with space-based and other ground-based observations, the AMBER magnetometer network provides a great opportunity to understand the electrodynamics that governs equatorial ionosphere motions. In this paper we present the longitudinal variability of the equatorial electrodynamics using the combination of instruments onboard SWARM and C/NOFS satellites and ground-based AMBER network. Both ground- and pace-based observations show stronger dayside and evening sector equatorial electrodynamics in the American and Asian sectors compared to the African sector. On the other hand, the African sector is home to stronger and year-round ionospheric bubbles/irregularities compared to the American and Asian sectors. This raises the question if the evening sector equatorial electrodynamics (vertical drift), which is believed to be the main cause for the enhancement of Rayleigh-Taylor (RT) instability growth rate, is stronger in the

Residential exposure to radiofrequency fields from mobile phone base stations, and broadcast transmitters: a population-based survey with personal meter.

Science.gov (United States)

Viel, J F; Clerc, S; Barrera, C; Rymzhanova, R; Moissonnier, M; Hours, M; Cardis, E

2009-08-01

Both the public perceptions, and most published epidemiologic studies, rely on the assumption that the distance of a particular residence from a base station or a broadcast transmitter is an appropriate surrogate for exposure to radiofrequency fields, although complex propagation characteristics affect the beams from antennas. The main goal of this study was to characterise the distribution of residential exposure from antennas using personal exposure meters. A total of 200 randomly selected people were enrolled. Each participant was supplied with a personal exposure meter for 24 h measurements, and kept a time-location-activity diary. Two exposure metrics for each radiofrequency were then calculated: the proportion of measurements above the detection limit (0.05 V/m), and the maximum electric field strength. Residential address was geocoded, and distance from each antenna was calculated. Much of the time, the recorded field strength was below the detection level (0.05 V/m), the FM band standing apart with a proportion above the detection threshold of 12.3%. The maximum electric field strength was always lower than 1.5 V/m. Exposure to GSM and DCS waves peaked around 280 m and 1000 m from the antennas. A downward trend was found within a 10 km range for FM. Conversely, UMTS, TV 3, and TV 4&5 signals did not vary with distance. Despite numerous limiting factors entailing a high variability in radiofrequency exposure assessment, but owing to a sound statistical technique, we found that exposures from GSM and DCS base stations increase with distance in the near source zone, to a maximum where the main beam intersects the ground. We believe these results will contribute to the ongoing public debate over the location of base stations and their associated emissions.

Securing Localization With Hidden and Mobile Base Stations

DEFF Research Database (Denmark)

Capkun, Srdjan; Srivastava, Mani; Cagalj, Mario

2006-01-01

localization based on hidden and mobile base stations. Our approach enables secure localization with a broad spectrum of localization techniques: ultrasonic or radio, based on received signal strength or signal time of flight. Through several examples we show how this approach can be used to secure nodecentric...

Monitoring of Electromagnetic Radiation from Cellular Base Stations in Kuwait

International Nuclear Information System (INIS)

Al-Otaibi, A.H.; Al-Ajmi, D.; Williams, T.; McGee, D.; Dennis, J.A.; Beg, M.U.

1998-01-01

A survey of the radio frequency electromagnetic environment in Kuwait was carried out. The primary purpose of this survey was to monitor electromagnetic radiation (EMR) field strength levels emitted by cellular base stations installed and operated by the Kuwait Mobile Telecommunications Company (MTC). Measurements were made at 26 cellular-phone base stations, chosen as a representative sample to include 14 school sites, 2 residential sites, 2 hospital sites, 3 ministerial building sites, 3 commercial sites and 1 typical stand-alone site. On all the selected sites measurements were made with a spectrum analyser to determine the emission level in the frequency bands used by the base station transmitters (917-960 MHz). The results indicated that total field strength, specifically due to the MTC base stations, found in public access areas, varied generally between 0.05 and 1.13 V.m -1 . These values are in the order of between 40 and 800 times lower than the new pan-European CENELEC pre-standard ENV 50166-2 'Human Exposure to Electromagnetic Fields'. In terms of power density the highest observed value (0.34 μW.m -2 ) was more than a thousand times below the prescribed standards. (author)

Modeling of earthquake ground motion in the frequency domain

Science.gov (United States)

Thrainsson, Hjortur

In recent years, the utilization of time histories of earthquake ground motion has grown considerably in the design and analysis of civil structures. It is very unlikely, however, that recordings of earthquake ground motion will be available for all sites and conditions of interest. Hence, there is a need for efficient methods for the simulation and spatial interpolation of earthquake ground motion. In addition to providing estimates of the ground motion at a site using data from adjacent recording stations, spatially interpolated ground motions can also be used in design and analysis of long-span structures, such as bridges and pipelines, where differential movement is important. The objective of this research is to develop a methodology for rapid generation of horizontal earthquake ground motion at any site for a given region, based on readily available source, path and site characteristics, or (sparse) recordings. The research includes two main topics: (i) the simulation of earthquake ground motion at a given site, and (ii) the spatial interpolation of earthquake ground motion. In topic (i), models are developed to simulate acceleration time histories using the inverse discrete Fourier transform. The Fourier phase differences, defined as the difference in phase angle between adjacent frequency components, are simulated conditional on the Fourier amplitude. Uniformly processed recordings from recent California earthquakes are used to validate the simulation models, as well as to develop prediction formulas for the model parameters. The models developed in this research provide rapid simulation of earthquake ground motion over a wide range of magnitudes and distances, but they are not intended to replace more robust geophysical models. In topic (ii), a model is developed in which Fourier amplitudes and Fourier phase angles are interpolated separately. A simple dispersion relationship is included in the phase angle interpolation. The accuracy of the interpolation

Illumination compensation in ground based hyperspectral imaging

Science.gov (United States)

Wendel, Alexander; Underwood, James

2017-07-01

Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

An Improved Method of Pose Estimation for Lighthouse Base Station Extension.

Science.gov (United States)

Yang, Yi; Weng, Dongdong; Li, Dong; Xun, Hang

2017-10-22

In 2015, HTC and Valve launched a virtual reality headset empowered with Lighthouse, the cutting-edge space positioning technology. Although Lighthouse is superior in terms of accuracy, latency and refresh rate, its algorithms do not support base station expansion, and is flawed concerning occlusion in moving targets, that is, it is unable to calculate their poses with a small set of sensors, resulting in the loss of optical tracking data. In view of these problems, this paper proposes an improved pose estimation algorithm for cases where occlusion is involved. Our algorithm calculates the pose of a given object with a unified dataset comprising of inputs from sensors recognized by all base stations, as long as three or more sensors detect a signal in total, no matter from which base station. To verify our algorithm, HTC official base stations and autonomous developed receivers are used for prototyping. The experiment result shows that our pose calculation algorithm can achieve precise positioning when a few sensors detect the signal.

Engineering graphics data entry for space station data base

Science.gov (United States)

Lacovara, R. C.

1986-01-01

The entry of graphical engineering data into the Space Station Data Base was examined. Discussed were: representation of graphics objects; representation of connectivity data; graphics capture hardware; graphics display hardware; site-wide distribution of graphics, and consolidation of tools and hardware. A fundamental assumption was that existing equipment such as IBM based graphics capture software and VAX networked facilities would be exploited. Defensible conclusions reached after study and simulations of use of these systems at the engineering level are: (1) existing IBM based graphics capture software is an adequate and economical means of entry of schematic and block diagram data for present and anticipated electronic systems for Space Station; (2) connectivity data from the aforementioned system may be incorporated into the envisioned Space Station Data Base with modest effort; (3) graphics and connectivity data captured on the IBM based system may be exported to the VAX network in a simple and direct fashion; (4) graphics data may be displayed site-wide on VT-125 terminals and lookalikes; (5) graphics hard-copy may be produced site-wide on various dot-matrix printers; and (6) the system may provide integrated engineering services at both the engineering and engineering management level.

Development of Base Transceiver Station Selection Algorithm for ...

African Journals Online (AJOL)

TEMS) equipment was carried out on the existing BTSs, and a linear algorithm optimization program based on the spectral link efficiency of each BTS was developed, the output of this site optimization gives the selected number of base station sites ...

Whistler-triggered chorus emissions observed during daytime at low latitude ground station Jammu

Science.gov (United States)

Pratap Patel, Ravindra; Singh, K. K.; Singh, A. K.; Singh, R. P.

In this paper, we present whistler-triggered chorus emission recorded during daytime at low latitude ground station Jammu (geomag. Lat. = 22 degree 26 minute N; L = 1.17) during the period from 1996 to 2003. After analysis of the eight years collected data, we found out 29 events, which are definitely identified as chorus emission triggered by whistlers. During the observation period the magnetic activity is high. Analysis shows that the whistlers have propagated along the geomagnetic field line having L-values lying between L = 1.9 and 4.4. These waves could have propagated along the geomagnetic field lines either in ducted mode or pro-longitudinal mode. The measured relative intensity of the triggered emission and whistler wave is approximately the same and also varies from one event to another. It is proposed that these waves are generated through a process of wave-particle interaction and wave-wave interactions. Related parameters of this interaction are computed for different L-value and wave amplitude. With the help of dynamic spectra of these emissions, the proposed mechanisms are explained.

Method of sharing mobile unit state information between base station routers

NARCIS (Netherlands)

Bosch, H.G.P.; Mullender, Sape J.; Polakos, Paul Anthony; Rajkumar, Ajay; Sundaram, Ganapathy S.

2007-01-01

The present invention provides a method of operating a first base station router. The method may include transmitting state information associated with at least one inactive mobile unit to at least one second base station router. The state information is usable to initiate an active session with the

Method of sharing mobile unit state information between base station routers

NARCIS (Netherlands)

Bosch, H.G.P.; Mullender, Sape J.; Polakos, Paul Anthony; Rajkumar, Ajay; Sundaram, Ganapathy S.

2010-01-01

The present invention provides a method of operating a first base station router. The method may include transmitting state information associated with at least one inactive mobile unit to at least one second base station router. The state information is usable to initiate an active session with the

Tissue Engineering of Cartilage on Ground-Based Facilities

Science.gov (United States)

Aleshcheva, Ganna; Bauer, Johann; Hemmersbach, Ruth; Egli, Marcel; Wehland, Markus; Grimm, Daniela

2016-06-01

Investigations under simulated microgravity offer the opportunity for a better understanding of the influence of altered gravity on cells and the scaffold-free three-dimensional (3D) tissue formation. To investigate the short-term influence, human chondrocytes were cultivated for 2 h, 4 h, 16 h, and 24 h on a 2D Fast-Rotating Clinostat (FRC) in DMEM/F-12 medium supplemented with 10 % FCS. We detected holes in the vimentin network, perinuclear accumulations of vimentin after 2 h, and changes in the chondrocytes shape visualised by F-actin staining after 4 h of FRC-exposure. Scaffold-free cultivation of chondrocytes for 7 d on the Random Positioning Machine (RPM), the FRC and the Rotating Wall Vessel (RWV) resulted in spheroid formation, a phenomenon already known from spaceflight experiments with chondrocytes (MIR Space Station) and thyroid cancer cells (SimBox/Shenzhou-8 space mission). The experiments enabled by the ESA-CORA-GBF programme gave us an optimal opportunity to study gravity-related cellular processes, validate ground-based facilities for our chosen cell system, and prepare long-term experiments under real microgravity conditions in space

Some unusual discrete VLF emissions observed at a low-latitude ground station at Agra

Directory of Open Access Journals (Sweden)

B. Singh

1997-08-01

Full Text Available A detailed analysis of the VLF emissions data obtained during occasional whistler campaigns at the low-latitude ground station Agra (geomagnetic latitude 17°1' N, L = 1.15 has yielded some unusual discrete VLF emissions of the rising type. These include (1 emissions occurring at time intervals increasing in ge ommetrical progression, (2 emissions occuring simulta neously in different frequency ranges and (3 emissions observed during daytime. In the present study, the observed characteristics of these emissions are described and interpreted. It is shown that the increasing time delay between different components of the emissions match closely with the propagation time delays between different hops of a whistler of dispersion 19 s1/2, the unusual occurrence of the emissions in two different frequency ranges approximately at the same time may possibly be linked with their generation at two different locations, and the occurrence of emissions during daytime may be due to propagation under the influence of equatorial anomaly.

A facility for training Space Station astronauts

Science.gov (United States)

Hajare, Ankur R.; Schmidt, James R.

1992-01-01

The Space Station Training Facility (SSTF) will be the primary facility for training the Space Station Freedom astronauts and the Space Station Control Center ground support personnel. Conceptually, the SSTF will consist of two parts: a Student Environment and an Author Environment. The Student Environment will contain trainers, instructor stations, computers and other equipment necessary for training. The Author Environment will contain the systems that will be used to manage, develop, integrate, test and verify, operate and maintain the equipment and software in the Student Environment.

Developments of space station; Uchu station no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, H. [National Space Development Agency of Japan, Tokyo (Japan)

1996-03-05

This paper introduces the Japanese experiment module (JEM) in developing a space station. The JEM consists of systems of a pressurizing section, an exposure section, a pressurizing portion of a supply section, a manipulator and an exposure portion of the supply section. The pressurizing section circulates and controls air so that crews can perform experiments under pressurized environment. The exposure section is a part in which experiments are carried out under exposure environment. The supply section runs between a station and the ground, with required devices loaded on it. The manipulator performs attaching a payload for the exposure section and replaces experimental samples. The JEM undergoes a schedule of fabricating an engineering model, testing for a certification a prototype flight model, and putting the model on a flight. The pressurizing section, exposure section and manipulator are at the stage of system tests. Surveillance of the JEM and control of the experiments are carried out at the Tsukuba Space Center. The Center is composed of a space experiment building, a zero-gravity environment testing building, an astronaut training building, a space station operating building, and a space station testing building. 7 figs., 2 tabs.

Tropospheric nitrogen dioxide column retrieval based on ground-based zenith-sky DOAS observations

Science.gov (United States)

Tack, F. M.; Hendrick, F.; Pinardi, G.; Fayt, C.; Van Roozendael, M.

2013-12-01

A retrieval approach has been developed to derive tropospheric NO2 vertical column amounts from ground-based zenith-sky measurements of scattered sunlight. Zenith radiance spectra are observed in the visible range by the BIRA-IASB Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument and analyzed by the DOAS technique, based on a least-squares spectral fitting. In recent years, this technique has shown to be a well-suited remote sensing tool for monitoring atmospheric trace gases. The retrieval algorithm is developed and validated based on a two month dataset acquired from June to July 2009 in the framework of the Cabauw (51.97° N, 4.93° E) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). Once fully operational, the retrieval approach can be applied to observations from stations of the Network for the Detection of Atmospheric Composition Change (NDACC). The obtained tropospheric vertical column amounts are compared with the multi-axis retrieval from the BIRA-IASB MAX-DOAS instrument and the retrieval from a zenith-viewing only SAOZ instrument (Système d'Analyse par Observations Zénithales), owned by Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS). First results show a good agreement for the whole time series with the multi-axis retrieval (R = 0.82; y = 0.88x + 0.30) as well as with the SAOZ retrieval (R = 0.85; y = 0.76x + 0.28 ). Main error sources arise from the uncertainties in the determination of tropospheric and stratospheric air mass factors, the stratospheric NO2 abundances and the residual amount in the reference spectrum. However zenith-sky measurements have been commonly used over the last decades for stratospheric monitoring, this study also illustrates the suitability for retrieval of tropospheric column amounts. As there are long time series of zenith-sky acquisitions available, the developed approach offers new perspectives with regard to the use of observations from the NDACC

Ground-based measurements of the vertical E-field in mountainous regions and the "Austausch" effect

Science.gov (United States)

Yaniv, Roy; Yair, Yoav; Price, Colin; Mkrtchyan, Hripsime; Lynn, Barry; Reymers, Artur

2017-06-01

Past measurements of the atmospheric vertical electric field (Ez or potential gradient) at numerous land stations showed a strong response of the daily electric field to a morning local effect known as ;Austausch; - the transport of electrical charges due to increased turbulence. In mountainous regions, nocturnal charge accumulation, followed by an attachment process to aerosols near the surface in valleys, known as the electrode effect, is lifted as a charged aerosol layer by anabatic (upslope) winds during the morning hours due to solar heating. Ground-based measurements during fair weather days were conducted at three mountain stations in Israel and Armenia. We present results of the mean diurnal variation of Ez and make comparisons with the well-known Carnegie curve and with past measurements of Ez on mountains. We report a good agreement between the mean diurnal curves of Ez at various mountain stations and the time of local sunrise when the Ez is found to increase. We attribute this morning maximum to the Austausch (or exchange) layer effect. We support our findings with conduction and turbulent current measurements showing high values of ions and charged aerosols being transported by winds from morning to noon local time, and by model simulations showing the convergence of winds in the early morning hours toward the mountain peak.

Probabilistic seismic hazard assessment for Point Lepreau Generating Station

Energy Technology Data Exchange (ETDEWEB)

Mullin, D. [New Brunswick Power Corp., Point Lepreau Generating Station, Lepreau, New Brunswick (Canada); Lavine, A. [AMEC Foster Wheeler Environment and Infrastructure Americas, Oakland, California (United States); Egan, J. [SAGE Engineers, Oakland, California (United States)

2015-09-15

A Probabilistic Seismic Hazard Assessment (PSHA) has been performed for the Point Lepreau Generating Station (PLGS). The objective is to provide characterization of the earthquake ground shaking that will be used to evaluate seismic safety. The assessment is based on the current state of knowledge of the informed scientific and engineering community regarding earthquake hazards in the site region, and includes two primary components-a seismic source model and a ground motion model. This paper provides the methodology and results of the PLGS PSHA. The implications of the updated hazard information for site safety are discussed in a separate paper. (author)

Probabilistic seismic hazard assessment for Point Lepreau Generating Station

Energy Technology Data Exchange (ETDEWEB)

Mullin, D., E-mail: dmullin@nbpower.com [New Brunswick Power Corporation, Point Lepreau Generating Station, Point Lepreau, NB (Canada); Lavine, A., E-mail: alexis.lavine@amecfw.com [AMEC Foster Wheeler Environment & Infrastructure Americas, Oakland, CA (United States); Egan, J., E-mail: jegan@sageengineers.com [SAGE Engineers, Oakland, CA (United States)

2015-07-01

A Probabilistic Seismic Hazard Assessment (PSHA) has been performed for the Point Lepreau Generating Station (PLGS). The objective is to provide characterization of the earthquake ground shaking that will be used to evaluate seismic safety. The assessment is based on the current state of knowledge of the informed scientific and engineering community regarding earthquake hazards in the site region, and includes two primary components--a seismic source model and a ground motion model. This paper provides the methodology and results of the PLGS PSHA. The implications of the updated hazard information for site safety are discussed in a separate paper. (author)

Monitoring Method and Apparatus Using Asynchronous, One-Way Transmission from Sensor to Base Station

Science.gov (United States)

Jensen, Scott L. (Inventor); Drouant, George J. (Inventor)

2013-01-01

A monitoring system is disclosed, which includes a base station and at least one sensor unit that is separate from the base station. The at least one sensor unit resides in a dormant state until it is awakened by the triggering of a vibration-sensitive switch. Once awakened, the sensor may take a measurement, and then transmit to the base station the measurement. Once data is transmitted from the sensor to the base station, the sensor may return to its dormant state. There may be various sensors for each base station and the various sensors may optionally measure different quantities, such as current, voltage, single-axis and/or three-axis magnetic fields.

A Ground-Based Study on Extruder Standoff Distance for the 3D Printing in Zero Gravity Technology Demonstration Mission

Science.gov (United States)

Prater, T. J.; Bean, Q. A.; Werkheiser, N. J.; Beshears, R. D.; Rolin, T. D.; Rabenberg, E. M.; Soohoo, H. A.; Ledbetter, F. E., III; Bell, S. C.

2017-01-01

Analysis of phase I specimens produced as part of the 3D printing in zero G technology demonstration mission exhibited some differences in structure and performance for specimens printed onboard the International Space Station (ISS) and specimens produced on the ground with the same printer prior to its launch. This study uses the engineering test unit for the printer, identical to the unit on ISS, to conduct a ground-based investigation of the impact of the distance between the extruder tip and the build tray on material outcomes. This standoff distance was not held constant for the phase I flight prints and is hypothesized to be a major source of the material variability observed in the phase I data set.

Development of a Ground-Based Analog to the Advanced Resistive Exercise Device Aboard the International Space Station

Science.gov (United States)

Newby, Nathaniel J.; Scott-Pandorf, M. M.; Caldwell, E.; DeWitt, J.K.; Fincke, R.; Peters, B.T.

2010-01-01

NASA and Wyle engineers constructed a Horizontal Exercise Fixture (HEF) that was patented in 2006. Recently modifications were made to HEF with the goal of creating a device that mimics squat exercise on the Advanced Resistive Exercise Device (ARED) and can be used by bed rest subjects who must remain supine during exercise. This project posed several engineering challenges, such as how best to reproduce the hip motions (we used a sled that allowed hip motion in the sagittal plane), how to counterweight the pelvis against gravity (we used a pulley and free-weight mechanism), and how to apply large loads (body weight plus squat load) to the shoulders while simultaneously supporting the back against gravity (we tested a standard and a safety bar that allowed movement in the subject s z-axis, both of which used a retractable plate for back support). METHODS An evaluation of the HEF was conducted with human subjects (3F, 3M), who performed sets of squat exercises of increasing load from 10-repetition maximum (RM) up to 1-RM. Three pelvic counterweight loads were tested along with each of the two back-support squat bars. Data collection included 3-dimensional ground reaction forces (GRF), muscle activation (EMG), body motion (video-based motion capture), and subjective comments. These data were compared with previous ground-based ARED study data. RESULTS All subjects in the evaluation were able to perform low- to high-loading squats on the HEF. Four of the 6 subjects preferred a pelvic counterweight equivalent to 60 percent of their body weight. Four subjects preferred the standard squat bar, whereas 2 female subjects preferred the safety bar. EMG data showed muscle activation in the legs and low back typical of squat motion. GRF trajectories and eccentric-concentric loading ratios were similar to ARED. CONCLUSION: Squat exercise performed on HEF approximated squat exercise on ARED.

Optimalisasi Kinerja (Internet Protocol) Ip Clock Pada Jaringan Base Transceiver Station (Bts)

OpenAIRE

Budiyanto, Setiyo; Saputra, Apipi

2016-01-01

Pada sistem komunikasi GSM (Global System for Mobile), BTS (Base Transceiver Station) merupakan jantung dari sebuah cell site layanan telekomunikasi. BTS merupakan perangkat pemancar dan penerima yang menangani akses radio dan berinteraksi langsung dengan Mobile Station (MS) melalui air interface. Sebuah optimasi kinerja ip clock pada base transceiver station (BTS) metode untuk sinkronisasi jaringan untuk jam global yang berasal dari jam GPS diakuisisi oleh sejumlah BTS. IP clock didistribusi...

Prospect and problems of gas based power stations of NTPC

International Nuclear Information System (INIS)

Suryanarayana, A.

1993-01-01

The policy of the Government of India concerning utilisation of natural gas resources of the country has undergone changes over the last few years. The government decided in 1985 to allocate natural gas for power generation and in the year 1986 approved the setting up of the first series of three gas based combined cycle power projects of National Thermal Power Corporation (NTPC). The problems of gas power stations of NTPC are discussed. These are high cost of generation, completion of transmission line works to match with the commissioning of gas power stations, high price of natural gas, and fixation of tariff for sale of power from gas based power stations. (N.B.)

QoS-Aware Resource Allocation for Network Virtualization in an Integrated Train Ground Communication System

Directory of Open Access Journals (Sweden)

Li Zhu

2018-01-01

Full Text Available Urban rail transit plays an increasingly important role in urbanization processes. Communications-Based Train Control (CBTC Systems, Passenger Information Systems (PIS, and Closed Circuit Television (CCTV are key applications of urban rail transit to ensure its normal operation. In existing urban rail transit systems, different applications are deployed with independent train ground communication systems. When the train ground communication systems are built repeatedly, limited wireless spectrum will be wasted, and the maintenance work will also become complicated. In this paper, we design a network virtualization based integrated train ground communication system, in which all the applications in urban rail transit can share the same physical infrastructure. In order to better satisfy the Quality of Service (QoS requirement of each application, this paper proposes a virtual resource allocation algorithm based on QoS guarantee, base station load balance, and application station fairness. Moreover, with the latest achievement of distributed convex optimization, we exploit a novel distributed optimization method based on alternating direction method of multipliers (ADMM to solve the virtual resource allocation problem. Extensive simulation results indicate that the QoS of the designed integrated train ground communication system can be improved significantly using the proposed algorithm.

Ground motion estimation for the elevated bridges of the Kyushu Shinkansen derailment caused by the foreshock of the 2016 Kumamoto earthquake based on the site-effect substitution method

Science.gov (United States)

Hata, Yoshiya; Yabe, Masaaki; Kasai, Akira; Matsuzaki, Hiroshi; Takahashi, Yoshikazu; Akiyama, Mitsuyoshi

2016-12-01

An earthquake of JMA magnitude 6.5 (first event) hit Kumamoto Prefecture, Japan, at 21:26 JST, April 14, 2016. Subsequently, an earthquake of JMA magnitude 7.3 (second event) hit Kumamoto and Oita Prefectures at 01:46 JST, April 16, 2016. An out-of-service Kyushu Shinkansen train carrying no passengers traveling on elevated bridges was derailed by the first event. This was the third derailment caused by an earthquake in the history of the Japanese Shinkansen, after one caused by the 2004 Mid-Niigata Prefecture Earthquake and another triggered by the 2011 Tohoku Earthquake. To analyze the mechanism of this third derailment, it is crucial to evaluate the strong ground motion at the derailment site with high accuracy. For this study, temporary earthquake observations were first carried out at a location near the bridge site; these observations were conducted because although the JMA Kumamoto Station site and the derailment site are closely located, the ground response characteristics at these sites differ. Next, empirical site amplification and phase effects were evaluated based on the obtained observation records. Finally, seismic waveforms during the first event at the bridge site of interest were estimated based on the site-effect substitution method. The resulting estimated acceleration and velocity waveforms for the derailment site include much larger amplitudes than the waveforms recorded at the JMA Kumamoto and MLIT Kumamoto station sites. The reliability of these estimates is confirmed by the finding that the same methods reproduce strong ground motions at the MLIT Kumamoto Station site accurately. These estimated ground motions will be useful for reasonable safety assessment of anti-derailment devices on elevated railway bridges.[Figure not available: see fulltext.

Estimation of High-Frequency Earth-Space Radio Wave Signals via Ground-Based Polarimetric Radar Observations

Science.gov (United States)

Bolen, Steve; Chandrasekar, V.

2002-01-01

Expanding human presence in space, and enabling the commercialization of this frontier, is part of the strategic goals for NASA's Human Exploration and Development of Space (HEDS) enterprise. Future near-Earth and planetary missions will support the use of high-frequency Earth-space communication systems. Additionally, increased commercial demand on low-frequency Earth-space links in the S- and C-band spectra have led to increased interest in the use of higher frequencies in regions like Ku and Ka-band. Attenuation of high-frequency signals, due to a precipitating medium, can be quite severe and can cause considerable disruptions in a communications link that traverses such a medium. Previously, ground radar measurements were made along the Earth-space path and compared to satellite beacon data that was transmitted to a ground station. In this paper, quantitative estimation of the attenuation along the propagation path is made via inter-comparisons of radar data taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and ground-based polarimetric radar observations. Theoretical relationships between the expected specific attenuation (k) of spaceborne measurements with ground-based measurements of reflectivity (Zh) and differential propagation phase shift (Kdp) are developed for various hydrometeors that could be present along the propagation path, which are used to estimate the two-way path-integrated attenuation (PIA) on the PR return echo. Resolution volume matching and alignment of the radar systems is performed, and a direct comparison of PR return echo with ground radar attenuation estimates is made directly on a beam-by-beam basis. The technique is validated using data collected from the TExas and Florida UNderflights (TEFLUN-B) experiment and the TRMM large Biosphere-Atmosphere experiment in Amazonia (LBA) campaign. Attenuation estimation derived from this method can be used for strategiC planning of communication systems for

[Electormagnetic field of the mobile phone base station: case study].

Science.gov (United States)

Bieńkowski, Paweł; Zubrzak, Bartłomiej; Surma, Robert

2011-01-01

The paper presents changes in the electromagnetic field intensity in a school building and its surrounding after the mobile phone base station installation on the roof of the school. The comparison of EMF intensity measured before the base station was launched (electromagnetic background measurement) and after starting its operation (two independent control measurements) is discussed. Analyses of measurements are presented and the authors also propose the method of the electromagnetic field distribution adjustment in the area of radiation antennas side lobe to reduce the intensity of the EMF level in the base station proximity. The presented method involves the regulation of the inclination. On the basis of the measurements, it was found that the EMF intensity increased in the building and its surroundings, but the values measured with wide margins meet the requirements of the Polish law on environmental protection.

On the effectiveness of single and multiple base station sleep modes in cellular networks

OpenAIRE

Marsan, Marco Ajmone; Chiaraviglio, Luca; Ciullo, Delia; Meo, Michela

2013-01-01

In this paper we study base station sleep modes that, by reducing power consumption in periods of low traffic, improve the energy efficiency of cellular access networks. We assume that when some base stations enter sleep mode, radio coverage and service provisioning are provided by the base stations that remain active, so as to guarantee that service is available over the whole area at all times. This may be an optimistic assumption in the case of the sparse base station layouts typical of ru...

47 CFR 90.656 - Responsibilities of base station licensees of Specialized Mobile Radio systems.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Responsibilities of base station licensees of... Bands § 90.656 Responsibilities of base station licensees of Specialized Mobile Radio systems. (a) The licensees of base stations that provide Specialized Mobile Radio service on a commercial basis of the use of...

Mobile phone base stations and adverse health effects: phase 1 of a population-based, cross-sectional study in Germany.

Science.gov (United States)

Blettner, M; Schlehofer, B; Breckenkamp, J; Kowall, B; Schmiedel, S; Reis, U; Potthoff, P; Schüz, J; Berg-Beckhoff, G

2009-02-01

The aim of this first phase of a cross-sectional study from Germany was to investigate whether proximity of residence to mobile phone base stations as well as risk perception is associated with health complaints. The researchers conducted a population-based, multi-phase, cross-sectional study within the context of a large panel survey regularly carried out by a private research institute in Germany. In the initial phase, reported on in this paper, 30,047 persons from a total of 51,444 who took part in the nationwide survey also answered questions on how mobile phone base stations affected their health. A list of 38 health complaints was used. A multiple linear regression model was used to identify predictors of health complaints including proximity of residence to mobile phone base stations and risk perception. Of the 30,047 participants (response rate 58.6%), 18.7% of participants were concerned about adverse health effects of mobile phone base stations, while an additional 10.3% attributed their personal adverse health effects to the exposure from them. Participants who were concerned about or attributed adverse health effects to mobile phone base stations and those living in the vicinity of a mobile phone base station (500 m) reported slightly more health complaints than others. A substantial proportion of the German population is concerned about adverse health effects caused by exposure from mobile phone base stations. The observed slightly higher prevalence of health complaints near base stations can not however be fully explained by attributions or concerns.

Observations of Earth space by self-powered stations in Antarctica.

Science.gov (United States)

Mende, S B; Rachelson, W; Sterling, R; Frey, H U; Harris, S E; McBride, S; Rosenberg, T J; Detrick, D; Doolittle, J L; Engebretson, M; Inan, U; Labelle, J W; Lanzerotti, L J; Weatherwax, A T

2009-12-01

Coupling of the solar wind to the Earth magnetosphere/ionosphere is primarily through the high latitude regions, and there are distinct advantages in making remote sensing observations of these regions with a network of ground-based observatories over other techniques. The Antarctic continent is ideally situated for such a network, especially for optical studies, because the larger offset between geographic and geomagnetic poles in the south enables optical observations at a larger range of magnetic latitudes during the winter darkness. The greatest challenge for such ground-based observations is the generation of power and heat for a sizable ground station that can accommodate an optical imaging instrument. Under the sponsorship of the National Science Foundation, we have developed suitable automatic observing platforms, the Automatic Geophysical Observatories (AGOs) for a network of six autonomous stations on the Antarctic plateau. Each station housed a suite of science instruments including a dual wavelength intensified all-sky camera that records the auroral activity, an imaging riometer, fluxgate and search-coil magnetometers, and ELF/VLF and LM/MF/HF receivers. Originally these stations were powered by propane fuelled thermoelectric generators with the fuel delivered to the site each Antarctic summer. A by-product of this power generation was a large amount of useful heat, which was applied to maintain the operating temperature of the electronics in the stations. Although a reasonable degree of reliability was achieved with these stations, the high cost of the fuel air lift and some remaining technical issues necessitated the development of a different type of power unit. In the second phase of the project we have developed a power generation system using renewable energy that can operate automatically in the Antarctic winter. The most reliable power system consists of a type of wind turbine using a simple permanent magnet rotor and a new type of power

78 FR 6344 - Certain Wireless Communications Base Stations and Components Thereof Notice of Receipt of...

Science.gov (United States)

2013-01-30

... INTERNATIONAL TRADE COMMISSION Certain Wireless Communications Base Stations and Components.... International Trade Commission has received a complaint entitled Certain Wireless Communications Base Stations... communications base stations and components thereof. The complaint names as respondents Telefonaktiebolaget LM...

National surveys of radiofrequency field strengths from radio base stations in Africa

Science.gov (United States)

Joyner, Ken H.; Van Wyk, Marthinus J.; Rowley, Jack T.

2014-01-01

The authors analysed almost 260 000 measurement points from surveys of radiofrequency (RF) field strengths near radio base stations in seven African countries over two time frames from 2001 to 2003 and 2006 to 2012. The results of the national surveys were compared, chronological trends investigated and potential exposures compared by technology and with frequency modulation (FM) radio. The key findings from thes data are that irrespective of country, the year and mobile technology, RF fields at a ground level were only a small fraction of the international human RF exposure recommendations. Importantly, there has been no significant increase in typical measured levels since the introduction of 3G services. The mean levels in these African countries are similar to the reported levels for countries of Asia, Europe and North America using similar mobile technologies. The median level for the FM services in South Africa was comparable to the individual but generally lower than the combined mobile services. PMID:24044904

National surveys of radiofrequency field strengths from radio base stations in Africa

International Nuclear Information System (INIS)

Joyner, K. H.; Van Wyk, M. J.; Rowley, J. T.

2014-01-01

The authors analysed almost 260 000 measurement points from surveys of radiofrequency (RF) field strengths near radio base stations in seven African countries over two time frames from 2001 to 2003 and 2006 to 2012. The results of the national surveys were compared, chronological trends investigated and potential exposures compared by technology and with frequency modulation (FM) radio. The key findings from these data are that irrespective of country, the year and mobile technology, RF fields at a ground level were only a small fraction of the international human RF exposure recommendations. Importantly, there has been no significant increase in typical measured levels since the introduction of 3G services. The mean levels in these African countries are similar to the reported levels for countries of Asia, Europe and North America using similar mobile technologies. The median level for the FM services in South Africa was comparable to the individual but generally lower than the combined mobile services. (authors)

Lunar base thermoelectric power station study

Science.gov (United States)

Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, G.; Brooks, Michael D.; Heshmatpour, Ben

2006-01-01

Under NASA's Project Prometheus, the Nuclear Systems Program, the Jet Propulsion Laboratory, Pratt & Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) program, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing and the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as the lunar base power station where kilowatts of power are required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this mission. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed and well as transport issues for this concept. The goal of the study was to review the entire life cycle of the unit to assess its technical problems and technology

78 FR 13895 - Certain Wireless Communications Base Stations and Components Thereof; Institution of...

Science.gov (United States)

2013-03-01

... the sale within the United States after importation of certain wireless communications base stations... United States after importation of certain wireless communications base stations and components thereof... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-871] Certain Wireless Communications Base...

Site selection model for new metro stations based on land use

Science.gov (United States)

Zhang, Nan; Chen, Xuewu

2015-12-01

Since the construction of metro system generally lags behind the development of urban land use, sites of metro stations should adapt to their surrounding situations, which was rarely discussed by previous research on station layout. This paper proposes a new site selection model to find the best location for a metro station, establishing the indicator system based on land use and combining AHP with entropy weight method to obtain the schemes' ranking. The feasibility and efficiency of this model has been validated by evaluating Nanjing Shengtai Road station and other potential sites.

Sail GTS ground system analysis: Avionics system engineering

Science.gov (United States)

Lawton, R. M.

1977-01-01

A comparison of two different concepts for the guidance, navigation and control test set signal ground system is presented. The first is a concept utilizing a ground plate to which crew station, avionics racks, electrical power distribution system, master electrical common connection assembly and marshall mated elements system grounds are connected by 4/0 welding cable. An alternate approach has an aluminum sheet interconnecting the signal ground reference points between the crew station and avionics racks. The comparison analysis quantifies the differences between the two concepts in terms of dc resistance, ac resistance and inductive reactance. These parameters are figures of merit for ground system conductors in that the system with the lowest impedance is the most effective in minimizing noise voltage. Although the welding cable system is probably adequate, the aluminum sheet system provides a higher probability of a successful system design.

Earthquake strong ground motion studies at the Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Wong, Ivan; Silva, W.; Darragh, R.; Stark, C.; Wright, D.; Jackson, S.; Carpenter, G.; Smith, R.; Anderson, D.; Gilbert, H.; Scott, D.

1989-01-01

Site-specific strong earthquake ground motions have been estimated for the Idaho National Engineering Laboratory assuming that an event similar to the 1983 M s 7.3 Borah Peak earthquake occurs at epicentral distances of 10 to 28 km. The strong ground motion parameters have been estimated based on a methodology incorporating the Band-Limited-White-Noise ground motion model coupled with Random Vibration Theory. A 16-station seismic attenuation and site response survey utilizing three-component portable digital seismographs was also performed for a five-month period in 1989. Based on the recordings of regional earthquakes, the effects of seismic attenuation in the shallow crust and along the propagation path and local site response were evaluated. This data combined with a detailed geologic profile developed for each site based principally on borehole data, was used in the estimation of the strong ground motion parameters. The preliminary peak horizontal ground accelerations for individual sites range from approximately 0.15 to 0.35 g. Based on the authors analysis, the thick sedimentary interbeds (greater than 20 m) in the basalt section attenuate ground motions as speculated upon in a number of previous studies

Space station evolution: Planning for the future

Science.gov (United States)

Diaz, Alphonso V.; Askins, Barbara S.

1987-06-01

The need for permanently manned presence in space has been recognized by the United States and its international partners for many years. The development of this capability was delayed due to the concurrent recognition that reusable earth-to-orbit transportation was also needed and should be developed first. While the decision to go ahead with a permanently manned Space Station was on hold, requirements for the use of the Station were accumulating as ground-based research and the data from unmanned spacecraft sparked the imagination of both scientists and entrepreneurs. Thus, by the time of the Space Station implementation decision in the early 1980's, a variety of disciplines, with a variety of requirements, needed to be accommodated on one Space Station. Additional future requirements could be forecast for advanced missions that were still in the early planning stages. The logical response was the development of a multi-purpose Space Station with the ability to evolve on-orbit to new capabilities as required by user needs and national or international decisions, i.e., to build an evolutionary Space Station. Planning for evolution is conducted in parallel with the design and development of the baseline Space Station. Evolution planning is a strategic management process to facilitate change and protect future decisions. The objective is not to forecast the future, but to understand the future options and the implications of these on today's decisions. The major actions required now are: (1) the incorporation of evolution provisions (hooks and scars) in the baseline Space Station; and (2) the initiation of an evolution advanced development program.

Space station evolution: Planning for the future

Science.gov (United States)

Diaz, Alphonso V.; Askins, Barbara S.

1987-01-01

The need for permanently manned presence in space has been recognized by the United States and its international partners for many years. The development of this capability was delayed due to the concurrent recognition that reusable earth-to-orbit transportation was also needed and should be developed first. While the decision to go ahead with a permanently manned Space Station was on hold, requirements for the use of the Station were accumulating as ground-based research and the data from unmanned spacecraft sparked the imagination of both scientists and entrepreneurs. Thus, by the time of the Space Station implementation decision in the early 1980's, a variety of disciplines, with a variety of requirements, needed to be accommodated on one Space Station. Additional future requirements could be forecast for advanced missions that were still in the early planning stages. The logical response was the development of a multi-purpose Space Station with the ability to evolve on-orbit to new capabilities as required by user needs and national or international decisions, i.e., to build an evolutionary Space Station. Planning for evolution is conducted in parallel with the design and development of the baseline Space Station. Evolution planning is a strategic management process to facilitate change and protect future decisions. The objective is not to forecast the future, but to understand the future options and the implications of these on today's decisions. The major actions required now are: (1) the incorporation of evolution provisions (hooks and scars) in the baseline Space Station; and (2) the initiation of an evolution advanced development program.

Evaluation of the National Solar Radiation Database (NSRDB) Using Ground-Based Measurements

Science.gov (United States)

Xie, Y.; Sengupta, M.; Habte, A.; Lopez, A.

2017-12-01

Solar resource is essential for a wide spectrum of applications including renewable energy, climate studies, and solar forecasting. Solar resource information can be obtained from ground-based measurement stations and/or from modeled data sets. While measurements provide data for the development and validation of solar resource models and other applications modeled data expands the ability to address the needs for increased accuracy and spatial and temporal resolution. The National Renewable Energy Laboratory (NREL) has developed and regular updates modeled solar resource through the National Solar Radiation Database (NSRDB). The recent NSRDB dataset was developed using the physics-based Physical Solar Model (PSM) and provides gridded solar irradiance (global horizontal irradiance (GHI), direct normal irradiance (DNI), and diffuse horizontal irradiance) at a 4-km by 4-km spatial and half-hourly temporal resolution covering 18 years from 1998-2015. A comprehensive validation of the performance of the NSRDB (1998-2015) was conducted to quantify the accuracy of the spatial and temporal variability of the solar radiation data. Further, the study assessed the ability of NSRDB (1998-2015) to accurately capture inter-annual variability, which is essential information for solar energy conversion projects and grid integration studies. Comparisons of the NSRDB (1998-2015) with nine selected ground-measured data were conducted under both clear- and cloudy-sky conditions. These locations provide a high quality data covering a variety of geographical locations and climates. The comparison of the NSRDB to the ground-based data demonstrated that biases were within +/- 5% for GHI and +/-10% for DNI. A comprehensive uncertainty estimation methodology was established to analyze the performance of the gridded NSRDB and includes all sources of uncertainty at various time-averaged periods, a method that is not often used in model evaluation. Further, the study analyzed the inter

Electromagnetic Radiation Exposure from Cellular Base Station: A ...

African Journals Online (AJOL)

Electromagnetic Radiation Exposure from Cellular Base Station: A Concern for Public ... as well as safety guidelines relating to exposure of non-ionizing radiation. Global System for Mobile Communication (GSM) operators claimed that their ...

From city’s station to station city. An integrative spatial approach to the (redevelopment of station areas

Directory of Open Access Journals (Sweden)

Ana Luísa Martins da Conceição

2014-12-01

Full Text Available Since its origin, the railway station has had a complicated relationship with the city, demanding periodical updates, particularly regarding spatial issues. With the aim of improving the liveability of station areas, current redevelopment projects are reconceptualising them as balanced transport ‘nodes’ and ‘places’ in the city. However, the proposed spatial solutions do not fully support the sought after economic, social and environmental performances. These intentions continue to be predominantly bounded with the (abstract planological level, not finding appropriate translation at the (concrete spatial design level. Further, the interdisciplinary nature of the highly complex planning and design processes of station areas, which should contribute to enhance the performance of their spaces, reinforces constraints and relegates architecture to a marginal role in this quest. It is thus necessary to understand how architecture can contribute to the improvement of the spatial performance of contemporary stations areas, supporting their current reconceptualization. To gain this understanding, the research explored the factors which influence the spatial definition and performance of European High Speed Train station areas, using “design research” and “research by design”. Via a theoretical integrative framework, synthesized from knowledge developed by architecture and other sciences, case studies of ‘through’ stations were analysed and compared. Six cases, encapsulating the most recurrent relative positions of the railway (infrastructure and the station building towards the(ir direct built environment, were chosen out of a large sample. For each category (cases with railway tracks at (a ground level, (b elevated level and (c underground level, two cases, featuring an adapted station building and a newly built one, were studied. Their physical and functional characteristics were mapped at several scales and moments (in history, as

System of wireless base stations employing shadow prices for power load balancing

NARCIS (Netherlands)

2011-01-01

In one aspect, a system is provided. In one embodiment, the system includes a plurality of wireless base stations that are located in a contiguous spatial coverage region of a cellular communication system. Each wireless base station that is configured to generate a coverage pilot beam to enable

Hydrogeology, simulated ground-water flow, and ground-water quality, Wright-Patterson Air Force Base, Ohio

Science.gov (United States)

Dumouchelle, D.H.; Schalk, C.W.; Rowe, G.L.; De Roche, J.T.

1993-01-01

Ground water is the primary source of water in the Wright-Patterson Air Force Base area. The aquifer consists of glacial sands and gravels that fill a buried bedrock-valley system. Consolidated rocks in the area consist of poorly permeable Ordovician shale of the Richmondian stage, in the upland areas, the Brassfield Limestone of Silurian age. The valleys are filled with glacial sediments of Wisconsinan age consisting of clay-rich tills and coarse-grained outwash deposits. Estimates of hydraulic conductivity of the shales based on results of displacement/recovery tests range from 0.0016 to 12 feet per day; estimates for the glacial sediments range from less than 1 foot per day to more than 1,000 feet per day. Ground water flow from the uplands towards the valleys and the major rivers in the region, the Great Miami and the Mad Rivers. Hydraulic-head data indicate that ground water flows between the bedrock and unconsolidated deposits. Data from a gain/loss study of the Mad River System and hydrographs from nearby wells reveal that the reach of the river next to Wright-Patterson Air Force Base is a ground-water discharge area. A steady-state, three-dimensional ground-water-flow model was developed to simulate ground-water flow in the region. The model contains three layers and encompasses about 100 square miles centered on Wright-Patterson Air Force Base. Ground water enters the modeled area primarily by river leakage and underflow at the model boundary. Ground water exits the modeled area primarily by flow through the valleys at the model boundaries and through production wells. A model sensitivity analysis involving systematic changes in values of hydrologic parameters in the model indicates that the model is most sensitive to decreases in riverbed conductance and vertical conductance between the upper two layers. The analysis also indicates that the contribution of water to the buried-valley aquifer from the bedrock that forms the valley walls is about 2 to 4

Investigation of ground-water contamination at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

Science.gov (United States)

Vroblesky, Don A.; Casey, Clifton C.

2007-01-01

The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used newly developed sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report uses data from a new type of pore-water sampler developed for this investigation and other methods to examine the subsurface contamination beneath the drainage ditch. Analysis of ground water from the samplers indicated that chlorobenzenes (maximum detected concentration of 160 micrograms per liter) are present in the ground water beneath the ditch. The concentrations of dissolved oxygen in the samples (less than 0.05-0.4 milligram per liter) showed that the ground water beneath and near the ditch is anaerobic, indicating that substantial chlorobenzene biodegradation in the aquifer beneath the ditch is unlikely. Probable alternative mechanisms of chlorobenzene removal in the ground water beneath the drainage ditch include sorption onto the organic-rich sediment and contaminant depletion by cattails through uptake, sorption, and localized soil aeration.

Study of the active layer at the Spanish Antarctic station “Gabriel de Castilla”, Deception Island, Antarctica

International Nuclear Information System (INIS)

Pablo, M.A. de; Molina, A.; Recio, C.; Ramos, M.; Goyanes, G.; Ropero, M.A.

2017-01-01

The degradation of permanent frozen ground (permafrost) and the increase in the thickness of the active layer may be caused both by natural processes (such as global climate change) and by anthropic activity, which changes the natural environmental conditions that allow its existence, as has been widely reported to occur in the northern polar and subpolar regions. In the case of Antarctica, some scientific research stations are located in areas with permafrost, such as the Spanish Antarctic station “Gabriel de Castilla” on Deception Island. In the place where the station is located, an important increase in erosion has been observed in recent years, including the excavation of new gullies and the erosion of the coastal cliffs. In order to develop an initial analysis of the possible effects of the station on the permafrost degradation, ground temperature has been monitored since 2012 and the thickness and of the active layer and the temperature, both inside and beneath the station, have also been sporadically measured. Here we show the results and discuss how the station reduces the freezing of the ground during the winter when the station is closed and facilitates the warming of the ground during the living periods of the station in the Antarctic summer. Those initial results and conclusions make necessary to continue the study of the permafrost and the active layer in the station site by systematic monitoring of the ground temperature and the thickness of the active layer. [es

Some unusual discrete VLF emissions observed at a low-latitude ground station at Agra

Directory of Open Access Journals (Sweden)

B. Singh

Full Text Available A detailed analysis of the VLF emissions data obtained during occasional whistler campaigns at the low-latitude ground station Agra (geomagnetic latitude 17°1' N, L = 1.15 has yielded some unusual discrete VLF emissions of the rising type. These include (1 emissions occurring at time intervals increasing in ge ommetrical progression, (2 emissions occuring simulta neously in different frequency ranges and (3 emissions observed during daytime. In the present study, the observed characteristics of these emissions are described and interpreted. It is shown that the increasing time delay between different components of the emissions match closely with the propagation time delays between different hops of a whistler of dispersion 19 s^1/2, the unusual occurrence of the emissions in two different frequency ranges approximately at the same time may possibly be linked with their generation at two different locations, and the occurrence of emissions during daytime may be due to propagation under the influence of equatorial anomaly.

Modal-pushover-based ground-motion scaling procedure

Science.gov (United States)

Kalkan, Erol; Chopra, Anil K.

2011-01-01

Earthquake engineering is increasingly using nonlinear response history analysis (RHA) to demonstrate the performance of structures. This rigorous method of analysis requires selection and scaling of ground motions appropriate to design hazard levels. This paper presents a modal-pushover-based scaling (MPS) procedure to scale ground motions for use in a nonlinear RHA of buildings. In the MPS method, the ground motions are scaled to match to a specified tolerance, a target value of the inelastic deformation of the first-mode inelastic single-degree-of-freedom (SDF) system whose properties are determined by the first-mode pushover analysis. Appropriate for first-mode dominated structures, this approach is extended for structures with significant contributions of higher modes by considering elastic deformation of second-mode SDF systems in selecting a subset of the scaled ground motions. Based on results presented for three actual buildings-4, 6, and 13-story-the accuracy and efficiency of the MPS procedure are established and its superiority over the ASCE/SEI 7-05 scaling procedure is demonstrated.

Finite element analysis of an underground protective test station subjected to severe ground motion

International Nuclear Information System (INIS)

Burchett, S.N.; Milloy, J.A.; Von Riesemann, W.A.

1974-01-01

A recoverable test station, to be used at a location very close to the detonation point of an underground nuclear test, was designed and tested. The design required that the station survive the very severe free-field stress and that the acceleration of the station be limited to a tolerable level. The predicted magnitude and time history of the free-field stress and acceleration indicated that the volcanic tuff medium and the materials of the proposed structure would exhibit nonlinear behavior, so that a transient dynamic analysis of a composite type structure involving nonlinear materials and large deformations was necessary. Parameter studies using a linear elastic dynamic finite element technique were first done to gain an understanding of the effect of the material properties and to study the response of various configurations of the protective structure to the transient loading. Based upon the results of these parameter studies and upon fielding considerations, a tentative design was chosen. This design was then evaluated using a newly developed finite element computer program. The results obtained from this analysis are compared to the field test results. (U.S.)

Primary Dendrite Array Morphology: Observations from Ground-based and Space Station Processed Samples

Science.gov (United States)

Tewari, Surendra; Rajamure, Ravi; Grugel, Richard; Erdmann, Robert; Poirier, David

2012-01-01

Influence of natural convection on primary dendrite array morphology during directional solidification is being investigated under a collaborative European Space Agency-NASA joint research program, "Microstructure Formation in Castings of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST)". Two Aluminum-7 wt pct Silicon alloy samples, MICAST6 and MICAST7, were directionally solidified in microgravity on the International Space Station. Terrestrially grown dendritic monocrystal cylindrical samples were remelted and directionally solidified at 18 K/cm (MICAST6) and 28 K/cm (MICAST7). Directional solidification involved a growth speed step increase (MICAST6-from 5 to 50 micron/s) and a speed decrease (MICAST7-from 20 to 10 micron/s). Distribution and morphology of primary dendrites is currently being characterized in these samples, and also in samples solidified on earth under nominally similar thermal gradients and growth speeds. Primary dendrite spacing and trunk diameter measurements from this investigation will be presented.

IMPROVED ALGORITHM FOR CALCULATING COMPLEX NON-EQUIPOTENTIAL GROUNDING DEVICES OF ELECTRICAL INSTALLATIONS TAKING INTO ACCOUNT CONDUCTIVITY OF NATURAL GROUNDINGS

Directory of Open Access Journals (Sweden)

K. A. Starkov

2017-08-01

Full Text Available Purpose. The method of natural concentrated groundings substitution by the set of electrodes taking them into account in the algorithm of electric characteristics calculation for complicated grounding connections of electric installation is offered. An equivalent model as a set of linear electrodes is chosen in accordance with two criteria: leakage resistance and potentials on the ground surface. Methodology. We have applied induced potential method and methods for computing branched electrical circuits with distributed parameters. Results. We have obtained the algorithm for calculating complex non-equipotential grounding connections, which makes it possible to obtain refined values of the potential distribution in the electric stations and substations with outdoor switchgear. Originality. For the first time, we have taking into account the conductivity of natural concentrated grounds by a set of vertical and horizontal electrodes based on equivalent electrical characteristics applied to a two-layer ground. Practical value. The using of the proposed calculation algorithm in the electric grids of JSC «Kharkivoblenergo» made it possible to determine the values of the potential distribution at short circuit in electrical substation taking into account the influence of the conductivity of natural concentrated groundings.

An aerial radiological survey of the Seabrook Nuclear Station and surrounding area, Seabrook, New Hampshire, July 1988

International Nuclear Information System (INIS)

1989-09-01

An aerial radiological survey was conducted over the Seabrook Nuclear Station, Seabrook, New Hampshire, during the period 6 July through 14 July 1988. The purpose of the 247-square-kilometer (96-square-mile) survey was to document the terrestrial gamma environment of the station and surrounding area. An exposure rate contour map at 1 meter above ground level (AGL) was constructed from the gamma data and overlaid on an aerial photograph and map of the area. Exposure rates measured in the area typically ranged form 9 to 12 microroentgens per hour (μR/h). In areas where water shielded the earth, lower exposure rates were measured. Ground-based exposure rate measurements and soil samples were obtained to support the aerial data. Oblique aerial photographs of the station were also acquired during the survey. 9 refs., 5 figs., 1 tab

Research on Single Base-Station Distance Estimation Algorithm in Quasi-GPS Ultrasonic Location System

Energy Technology Data Exchange (ETDEWEB)

Cheng, X C; Su, S J; Wang, Y K; Du, J B [Instrument Department, College of Mechatronics Engineering and Automation, National University of Defense Technology, ChangSha, Hunan, 410073 (China)

2006-10-15

In order to identify each base-station in quasi-GPS ultrasonic location system, a unique pseudo-random code is assigned to each base-station. This article primarily studies the distance estimation problem between Autonomous Guide Vehicle (AGV) and single base-station, and then the ultrasonic spread-spectrum distance measurement Time Delay Estimation (TDE) model is established. Based on the above model, the envelope correlation fast TDE algorithm based on FFT is presented and analyzed. It shows by experiments that when the m sequence used in the received signal is as same as the reference signal, there will be a sharp correlation value in their envelope correlation function after they are processed by the above algorithm; otherwise, the will be no prominent correlation value. So, the AGV can identify each base-station easily.

Research on Single Base-Station Distance Estimation Algorithm in Quasi-GPS Ultrasonic Location System

International Nuclear Information System (INIS)

Cheng, X C; Su, S J; Wang, Y K; Du, J B

2006-01-01

In order to identify each base-station in quasi-GPS ultrasonic location system, a unique pseudo-random code is assigned to each base-station. This article primarily studies the distance estimation problem between Autonomous Guide Vehicle (AGV) and single base-station, and then the ultrasonic spread-spectrum distance measurement Time Delay Estimation (TDE) model is established. Based on the above model, the envelope correlation fast TDE algorithm based on FFT is presented and analyzed. It shows by experiments that when the m sequence used in the received signal is as same as the reference signal, there will be a sharp correlation value in their envelope correlation function after they are processed by the above algorithm; otherwise, the will be no prominent correlation value. So, the AGV can identify each base-station easily

Polycapillary based μXRF station for 3D colour tomography

Science.gov (United States)

Hampai, D.; Cherepennikov, Yu. M.; Liedl, A.; Cappuccio, G.; Capitolo, E.; Iannarelli, M.; Azzutti, C.; Gladkikh, Yu. P.; Marcelli, A.; Dabagov, S. B.

2018-04-01

The "Rainbow X-Ray" (RXR) experimental station at XLab Frascati of the Frascati's National Laboratories (LNF) INFN is a dedicated station for X-ray fluorescence studies based on the use of polycapillary lenses in a confocal geometry. The flexible RXR layout allows investigating specimens of the dimensions ranging from several millimeters up to half meter and weighting up to several tens of kilograms. Compared to similar existing XRF stations, apart of the possibility for investigating large samples, the main advantage of this equipment is the detection system with two spectrometers optimized to work separately at high and at low X-ray energies. The confocal geometry combined with a 3-axes fine motion system makes possible 3D μXRF elemental tomographic acquisitions (colour tomography). At present this station in operation at high XRF energies is used for cultural heritage and geological applications. We present and discuss here the analytical performances of this experimental station pointing out the advantages in different application areas.

Base Station Antenna Pattern Distortion in Practical Urban Deployment Scenarios

DEFF Research Database (Denmark)

Rodriguez Larrad, Ignacio; Nguyen, Huan Cong; Sørensen, Troels Bundgaard

2014-01-01

In real urban deployments, base station antennas are typically not placed in free space conditions. Therefore, the radiation pattern can be affected by mounting structures and nearby obstacles located in the proximity of the antenna (near-field), which are often not taken into consideration. Also...... presents a combination of near-field and far-field simulations aimed to provide an overview of the distortion experienced by the base station antenna pattern in two different urban deployment scenarios: rooftop and telecommunications tower. The study illustrates how, in comparison with the near...

Scaling earthquake ground motions for performance-based assessment of buildings

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.; Hamburger, R.O.

2011-01-01

The impact of alternate ground-motion scaling procedures on the distribution of displacement responses in simplified structural systems is investigated. Recommendations are provided for selecting and scaling ground motions for performance-based assessment of buildings. Four scaling methods are studied, namely, (1)geometric-mean scaling of pairs of ground motions, (2)spectrum matching of ground motions, (3)first-mode-period scaling to a target spectral acceleration, and (4)scaling of ground motions per the distribution of spectral demands. Data were developed by nonlinear response-history analysis of a large family of nonlinear single degree-of-freedom (SDOF) oscillators that could represent fixed-base and base-isolated structures. The advantages and disadvantages of each scaling method are discussed. The relationship between spectral shape and a ground-motion randomness parameter, is presented. A scaling procedure that explicitly considers spectral shape is proposed. ?? 2011 American Society of Civil Engineers.

Assessment of Radiofrequency Radiation Distribution around Mobile Base Stations in Makurdi, Benue State

OpenAIRE

J.T. Iortile; E.H. Agba

2014-01-01

The radiofrequency field levels of selected MTN and ZAIN base stations in Makurdi were measured using electromagnetic field tester (EMF 827, Lutron). Measurements were done at distances of approximately 5.00, 10.00, 15.00 and 20.00 metres for each base station at the North, South, West, and East directions. Results shows that the average magnetic field levels of MTN and ZAIN base station ranged between 0.09 μT to 0.15 μT. The mean electric field values for eye, brain and muscles ranged betwee...

Public safety assessment of electromagnetic radiation exposure from mobile base stations.

Science.gov (United States)

Alhekail, Z O; Hadi, M A; Alkanhal, M A

2012-09-01

Exposure of the general public to electromagnetic radiation originating from randomly selected GSM/WCDMA base stations in Riyadh, Kingdom of Saudi Arabia has been assessed in the context of the International Commission on Non-Ionising Radiation Protection (ICNIRP) guidelines. The purpose of the measurement was to record the maximum power density of signals to estimate possible worst case exposure at each measurement location. These power density measurements were carried out at 60 mobile base stations located in different regions of the city. For each of these sites, three sectors were operational, yielding a total of 180 sectors. Two positions were identified per site with the greatest power density values. Exposures from these base stations were generally found to be in the range of 0.313 to 0.00000149% of the ICNIRP general public reference level, and the greatest exposure near any of the base stations was 21.96 mW m(-2) for a wideband measurement in the 75-3000 MHz frequency range. Analysis of the measured data reveals several trends for different mobile bands with respect to maximum exposure in those locations. Additionally, a simplified calculation method for the electromagnetic fields was used to compare calculated and the measured data. It was determined, on the basis of both results of the measurements and calculations carried out for these selected base stations, that members of the public would not be exposed to in excess of a small fraction of the ICNIRP guidelines at any of those sites. These are first such measurements to be made in the Middle East and provide assurance that exposures in this region of the world do not seem to be any greater than elsewhere.

Hanford Ground-Water Data Base management guide

International Nuclear Information System (INIS)

Rieger, J.T.; Mitchell, P.J.; Muffett, D.M.; Fruland, R.M.; Moore, S.B.; Marshall, S.M.

1990-02-01

This guide describes the Hanford Ground-Water Data Base (HGWDB), a computerized data base used to store hydraulic head, sample analytical, temperature, geologic, and well-structure information for ground-water monitoring wells on the Hanford Site. These data are stored for the purpose of data retrieval for report generation and also for historical purposes. This guide is intended as an aid to the data base manager and the various staff authorized to enter and verify data, maintain the data base, and maintain the supporting software. This guide focuses on the structure of the HGWDB, providing a fairly detailed description of the programs, files, and parameters. Data-retrieval instructions for the general user of the HGWDB will be found in the HGWDB User's Manual. 6 figs

Measurements of MIMO Indoor Channels at 1800 MHz with Multiple Indoor and Outdoor Base Stations

Directory of Open Access Journals (Sweden)

Jaldén Niklas

2007-01-01

Full Text Available This paper proposes several configurations for multiple base stations in indoor MIMO systems and compares their performance. The results are based on channel measurements realized with a MIMO testbed. The receiver was moved along several routes and floors on an office building. Both outdoor and indoor locations are considered for the transmitters or base stations, which allow the analysis of not only indoor but also outdoor-to-indoor environment. The use of 2 base stations with different system level combinations of the two is analyzed. We show that the configuration with base station selection provides almost as good performance as a full water-filling scheme when the 2 base stations are placed at different locations. Also the spatial correlation properties for the different configurations are analyzed and the importance of considering path loss when evaluating capacity is highlighted.

Greening radio access networks using distributed base station architectures

DEFF Research Database (Denmark)

Kardaras, Georgios; Soler, José; Dittmann, Lars

2010-01-01

Several actions for developing environmentally friendly technologies have been taken in most industrial fields. Significant resources have also been devoted in mobile communications industry. Moving towards eco-friendly alternatives is primarily a social responsibility for network operators....... However besides this, increasing energy efficiency represents a key factor for reducing operating expenses and deploying cost effective mobile networks. This paper presents how distributed base station architectures can contribute in greening radio access networks. More specifically, the advantages...... energy saving. Different subsystems have to be coordinated real-time and intelligent network nodes supporting complicated functionalities are necessary. Distributed base station architectures are ideal for this purpose mainly because of their high degree of configurability and self...

Programmable Ultra-Lightweight System Adaptable Radio Satellite Base Station

Science.gov (United States)

Varnavas, Kosta; Sims, Herb

2015-01-01

With the explosion of the CubeSat, small sat, and nanosat markets, the need for a robust, highly capable, yet affordable satellite base station, capable of telemetry capture and relay, is significant. The Programmable Ultra-Lightweight System Adaptable Radio (PULSAR) is NASA Marshall Space Flight Center's (MSFC's) software-defined digital radio, developed with previous Technology Investment Programs and Technology Transfer Office resources. The current PULSAR will have achieved a Technology Readiness Level-6 by the end of FY 2014. The extensibility of the PULSAR will allow it to be adapted to perform the tasks of a mobile base station capable of commanding, receiving, and processing satellite, rover, or planetary probe data streams with an appropriate antenna.

The Engineering Strong Ground Motion Network of the National Autonomous University of Mexico

Science.gov (United States)

Velasco Miranda, J. M.; Ramirez-Guzman, L.; Aguilar Calderon, L. A.; Almora Mata, D.; Ayala Hernandez, M.; Castro Parra, G.; Molina Avila, I.; Mora, A.; Torres Noguez, M.; Vazquez Larquet, R.

2014-12-01

The coverage, design, operation and monitoring capabilities of the strong ground motion program at the Institute of Engineering (IE) of the National Autonomous University of Mexico (UNAM) is presented. Started in 1952, the seismic instrumentation intended initially to bolster earthquake engineering projects in Mexico City has evolved into the largest strong ground motion monitoring system in the region. Today, it provides information not only to engineering projects, but also to the near real-time risk mitigation systems of the country, and enhances the general understanding of the effects and causes of earthquakes in Mexico. The IE network includes more than 100 free-field stations and several buildings, covering the largest urban centers and zones of significant seismicity in Central Mexico. Of those stations, approximately one-fourth send the observed acceleration to a processing center in Mexico City continuously, and the rest require either periodic visits for the manual recovery of the data or remote interrogation, for later processing and cataloging. In this research, we document the procedures and telecommunications systems used systematically to recover information. Additionally, we analyze the spatial distribution of the free-field accelerographs, the quality of the instrumentation, and the recorded ground motions. The evaluation criteria are based on the: 1) uncertainty in the generation of ground motion parameter maps due to the spatial distribution of the stations, 2) potential of the array to provide localization and magnitude estimates for earthquakes with magnitudes greater than Mw 5, and 3) adequacy of the network for the development of Ground Motion Prediction Equations due to intra-plate and intra-slab earthquakes. We conclude that the monitoring system requires a new redistribution, additional stations, and a substantial improvement in the instrumentation and telecommunications. Finally, we present an integral plan to improve the current network

Ion cyclotron waves: Direct compariosn between ground-based measurements and observations in the source region

International Nuclear Information System (INIS)

Perraut, S.; Gendrin, R.; Roux, A.; de Villedary, C.

1984-01-01

Simultaneous measurements of ion cyclotron waves (ICW's) were performed on GEOS spacecraft and in the vicinity of their magnetic footprints with the French Mobile station. The detailed comparison between the two sets of data shown that while ICW's having F + gyrofrequency at the equator, generally propagate to the ground, only 50% of those generated above F/sub He/ can reach the ground station. It is shown that these results are in good agreement with the conclusions that Rauch and Roux [1982] drew on the basis of measurements reported by Young et al 1981]. In an He + -rich plasma, ICW's with F>F/sub He/ suffer a reflection where the frequency locally matches the local bi-ion hybrid frequency. We extend the calculations of Rauch and Roux and calculate, as a function of the He + concentration, the tunneling of ICW's through the stopband induced by the presence of minor He + ions. It is shown that the transmission coefficient strongly depends upon the wave frequency for a given He + abundance ratio. The results obtained are shown to be supported by existing observations

Research on Application of Automatic Weather Station Based on Internet of Things

Science.gov (United States)

Jianyun, Chen; Yunfan, Sun; Chunyan, Lin

2017-12-01

In this paper, the Internet of Things is briefly introduced, and then its application in the weather station is studied. A method of data acquisition and transmission based on NB-iot communication mode is proposed, Introduction of Internet of things technology, Sensor digital and independent power supply as the technical basis, In the construction of Automatic To realize the intelligent interconnection of the automatic weather station, and then to form an automatic weather station based on the Internet of things. A network structure of automatic weather station based on Internet of things technology is constructed to realize the independent operation of intelligent sensors and wireless data transmission. Research on networking data collection and dissemination of meteorological data, through the data platform for data analysis, the preliminary work of meteorological information publishing standards, networking of meteorological information receiving terminal provides the data interface, to the wisdom of the city, the wisdom of the purpose of the meteorological service.

Daily snow depth measurements from 195 stations in the United States

Energy Technology Data Exchange (ETDEWEB)

Allison, L.J. [ed.] [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Easterling, D.R.; Jamason, P.; Bowman, D.P.; Hughes, P.Y.; Mason, E.H. [National Oceanic and Atmospheric Administration, Asheville, NC (United States). National Climatic Data Center

1997-02-01

This document describes a database containing daily measurements of snow depth at 195 National Weather Service (NWS) first-order climatological stations in the United States. The data have been assembled and made available by the National Climatic Data Center (NCDC) in Asheville, North Carolina. The 195 stations encompass 388 unique sampling locations in 48 of the 50 states; no observations from Delaware or Hawaii are included in the database. Station selection criteria emphasized the quality and length of station records while seeking to provide a network with good geographic coverage. Snow depth at the 388 locations was measured once per day on ground open to the sky. The daily snow depth is the total depth of the snow on the ground at measurement time. The time period covered by the database is 1893--1992; however, not all station records encompass the complete period. While a station record ideally should contain daily data for at least the seven winter months (January through April and October through December), not all stations have complete records. Each logical record in the snow depth database contains one station`s daily data values for a period of one month, including data source, measurement, and quality flags.

Enhancing base station connectivity with directional information of movement

Directory of Open Access Journals (Sweden)

Eugene Kim

2016-09-01

Full Text Available High-performance smartphones with various sensor capabilities, including the inertial measurement unit, allow us to have higher freedom to localize our movements and utilize them for other applications. In this paper, we present a simple method to estimate the heading of a user using only a digital compass, accelerometer, and gyroscope. Several experiments were conducted using an Apple iPhone. In addition, we also present an algorithm to reduce the number of handover attempts in a dense base station environment. A series of simulations were conducted on OPNET in various emulated environments to present the effectiveness of the proposed method. The simulation results show that our proposed algorithm effectively reduces the ping-pong effect in a dense base station environment.

Energy Sharing Framework for Microgrid-Powered Cellular Base Stations

KAUST Repository

Farooq, Muhammad Junaid; Ghazzai, Hakim; Kadri, Abdullah; Elsawy, Hesham; Alouini, Mohamed-Slim

2017-01-01

Cellular base stations (BSs) are increasingly becoming equipped with renewable energy generators to reduce operational expenditures and carbon footprint of wireless communications. Moreover, advancements in the traditional electricity grid allow two

Estimating atmospheric visibility using synergy of MODIS data and ground-based observations

Science.gov (United States)

Komeilian, H.; Mohyeddin Bateni, S.; Xu, T.; Nielson, J.

2015-05-01

Dust events are intricate climatic processes, which can have adverse effects on human health, safety, and the environment. In this study, two data mining approaches, namely, back-propagation artificial neural network (BP ANN) and supporting vector regression (SVR), were used to estimate atmospheric visibility through the synergistic use of Moderate Resolution Imaging Spectroradiometer (MODIS) Level 1B (L1B) data and ground-based observations at fourteen stations in the province of Khuzestan (southwestern Iran), during 2009-2010. Reflectance and brightness temperature in different bands (from MODIS) along with in situ meteorological data were input to the models to estimate atmospheric visibility. The results show that both models can accurately estimate atmospheric visibility. The visibility estimates from the BP ANN network had a root-mean-square error (RMSE) and Pearson's correlation coefficient (R) of 0.67 and 0.69, respectively. The corresponding RMSE and R from the SVR model were 0.59 and 0.71, implying that the SVR approach outperforms the BP ANN.

Recent Advances in Observations of Ground-level Auroral Kilometric Radiation

Science.gov (United States)

Labelle, J. W.; Ritter, J.; Pasternak, S.; Anderson, R. R.; Kojima, H.; Frey, H. U.

2011-12-01

Recently LaBelle and Anderson [2011] reported the first definitive observations of AKR at ground level, confirmed through simultaneous measurements on the Geotail spacecraft and at South Pole Station, Antarctica. The initial observations consisted of three examples recorded in 2004. An Antarctic observing site is critical for observing ground level AKR which is obscured by man-made broadcast signals at northern hemisphere locations. Examination of 2008 austral winter radio data from Antarctic Automatic Geophysical Observatories (AGOs) of the Polar Experiment Network for Geospace Upper-atmosphere Investigations (PENGUIn) network and South Pole Station reveals 37 ground level AKR events on 23 different days, 30 of which are confirmed by correlation with AKR observed with the Geotail spacecraft. The location of the Geotail spacecraft appears to be a significant factor enabling coincident measurements. Six of the AKR events are detected at two or three ground-level observatories separated by approximately 500 km, suggesting that the events illuminate an area comparable to a 500-km diameter. For 14 events on ten nights, photometer and all-sky imager data from South Pole and AGOs were examined; in ten cases, locations of auroral arcs could be determined at the times of the events. In eight of those cases, the AKR was detected at observatories poleward of the auroral arcs, and in the other two cases the aurora was approximately overhead at the observatory where AKR was detected. These observations suggest that the AKR signals may be ducted to ground level along magnetic field lines rather than propagating directly from the AKR source region of approximately 5000 km altitude. Correlations between structures in the AKR and intensifications of auroral arcs are occasionally observed but are rare. The ground-level AKR events have a local time distribution similar to that of AKR observed from satellites, peaking in the pre-midnight to midnight sector. This data base of >30

Monitoring of nuclear power stations

International Nuclear Information System (INIS)

Ull, E.; Labudda, H.J.

1987-01-01

The purpose of the invention is to create a process for undelayed automated detection and monitoring of accidents in the operation of nuclear power stations. According to the invention, this problem is solved by the relevant local measurements, such as radiation dose, components and type of radiation and additional relevant meteorological parameters being collected by means of wellknown data collection platforms, these being transmitted via transmission channels by means of satellites to suitable worldwide situated receiving stations on the ground, being processed there and being evaluated to recognise accidents. The local data collection platforms are used in the immediate vicinity of the nuclear power station. The use of aircraft, ships and balloons as data collection systems is also intended. (HWJ)

Measurements of total and tropospheric ozone from IASI: comparison with correlative satellite, ground-based and ozonesonde observations

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A. Boynard

2009-08-01

Full Text Available In this paper, we present measurements of total and tropospheric ozone, retrieved from infrared radiance spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI, which was launched on board the MetOp-A European satellite in October 2006. We compare IASI total ozone columns to Global Ozone Monitoring Experiment-2 (GOME-2 observations and ground-based measurements from the Dobson and Brewer network for one full year of observations (2008. The IASI total ozone columns are shown to be in good agreement with both GOME-2 and ground-based data, with correlation coefficients of about 0.9 and 0.85, respectively. On average, IASI ozone retrievals exhibit a positive bias of about 9 DU (3.3% compared to both GOME-2 and ground-based measurements. In addition to total ozone columns, the good spectral resolution of IASI enables the retrieval of tropospheric ozone concentrations. Comparisons of IASI tropospheric columns to 490 collocated ozone soundings available from several stations around the globe have been performed for the period of June 2007–August 2008. IASI tropospheric ozone columns compare well with sonde observations, with correlation coefficients of 0.95 and 0.77 for the [surface–6 km] and [surface–12 km] partial columns, respectively. IASI retrievals tend to overestimate the tropospheric ozone columns in comparison with ozonesonde measurements. Positive average biases of 0.15 DU (1.2% and 3 DU (11% are found for the [surface–6 km] and for the [surface–12 km] partial columns respectively.

Two-way laser ranging and time transfer experiments between LOLA and an Earth-based satellite laser ranging station

Science.gov (United States)

Mao, D.; Sun, X.; Neumann, G. A.; Barker, M. K.; Mazarico, E. M.; Hoffman, E.; Zagwodzki, T. W.; Torrence, M. H.; Mcgarry, J.; Smith, D. E.; Zuber, M. T.

2017-12-01

Satellite Laser Ranging (SLR) has established time-of-flight measurements with mm precision to targets orbiting the Earth and the Moon using single-ended round-trip laser ranging to passive optical retro-reflectors. These high-precision measurements enable advances in fundamental physics, solar system dynamics. However, the received signal strength suffers from a 1/R4 decay, which makes it impractical for measuring distances beyond the Moon's orbit. On the other hand, for a two-way laser transponder pair, where laser pulses are both transmitted to and received from each end of the laser links, the signal strength at both terminals only decreases by 1/R2, thus allowing a greater range of distances to be covered. The asynchronous transponder concept has been previously demonstrated by a test in 2005 between the Mercury Laser Altimeter (MLA) aboard the MESSENGER (MErcury Surface, Space ENvironment, Geochemistry, and Ranging) spacecraft and NASA's Goddard Geophysical and Astronomical Observatory (GGAO) at a distance of ˜0.16 AU. In October 2013, regular two-way transponder-type range measurements were obtained over 15 days between the Lunar Laser Communication Demonstration (LLCD) aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft and NASA's ground station at White Sands, NM. The Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO) provides us a unique capability to test time-transfer beyond near Earth orbit. Here we present results from two-way transponder-type experiments between LOLA and GGAO conducted in March 2014 and 2017. As in the time-transfer by laser link (T2L2) experiments between a ground station and an earth-orbiting satellite, LOLA and GGAO ranged to each other simultaneously in these two-way tests at lunar distance. We measured the time-of-flight while cross-referencing the spacecraft clock to the ground station time. On May 4th, 2017, about 20 minutes of two-way measurements were collected. The

Applying spaceborne reflectivity measurements for calculation of the solar ultraviolet radiation at ground level

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P. N. den Outer

2012-12-01

Full Text Available Long-term analysis of cloud effects on ultraviolet (UV radiation on the ground using spaceborne observations requires the use of instruments that have operated consecutively. The longest data record can be built from the reflectivity measurements produced by the instruments Total Ozone Mapping Spectrometers (TOMS flown on Nimbus 7 from 1979 to 1992, TOMS on Earth Probe from 1996 to 2005, and the Ozone Monitoring Instrument (OMI flown on EOS Aura since 2004. The reflectivity data produced by TOMS on Earth Probe is only included until 2002. A comparison is made with cloud effects inferred from ground-based pyranometer measurements at over 83 World Radiation Data Centre stations. Modelled UV irradiances utilizing the standard reflectivity are compared with measurements of UV irradiances at eight European low-elevation stations. The reflectivity data of the two TOMS instruments shows a consistent agreement, and the required corrections are of low percentage, i.e. 2–3%. In contrast, the reflectivity product of OMI requires correction of 7–10%, and a solar angle dependency therein is more pronounced. These corrections were inferred from a comparison with pyranometer data, and tested using the UV measurements. The average reduction of UV radiation due to clouds for all sites together indicates a small trend: a diminishing cloudiness, in line with ground-based UV observations. Uncorrected implementation of the reflectivity data would have indicated the opposite.

An optimal area was established for reflectivity data for the calculation of daily sums of UV radiation. It measures approximately 1.25° in latitudinal direction for square-shaped areas overhead the ground-based UV stations. Such an area can be traversed within 5 to 7 h at the average wind speeds found for the West European continent.

PSC and volcanic aerosol routine observations in Antarctica by UV-visible ground-based spectrometry

Science.gov (United States)

Sarkissian, A.; Pommereau, J. P.; Goutail, F.

1994-01-01

Polar statospheric clouds (PSC) and stratospheric aerosol can be observed by ground-based UV-visible spectrometry by looking at the variation of the color of the sky during twilight. A radiative transfer model shows that reddenings are caused by high altitude (22-28 km) thin layers of scatterers, while low altitude (12-20 km) thick ones result in blueings. The color index method applied on 4 years of observations at Dumont d'Urville (67 deg S), from 1988 to 1991, shows that probably because the station is located at the edge of the vortex, dense PSC are uncommon. More unexpected is the existence of a systematic seasonal variation of the color of the twilight sky - bluer at spring - which reveals the formation of a dense scattering layer at or just above the tropopause at the end of the winter. Large scattering layers are reported above the station in 1991, first in August around 12-14 km, later in September at 22-24 km. They are attributed to volcanic aerosol from Mt Hudson and Mt Pinatubo respectively, which erupted in 1991. Inspection of the data shows that the lowest entered rapidly into the polar vortex but not the highest which remained outside, demonstrating that the vortex was isolated at 22-26 km.

Mobile phone base stations and early childhood cancers: case-control study.

Science.gov (United States)

Elliott, Paul; Toledano, Mireille B; Bennett, J; Beale, L; de Hoogh, K; Best, N; Briggs, D J

2010-06-22

To investigate the risk of early childhood cancers associated with the mother's exposure to radiofrequency from and proximity to macrocell mobile phone base stations (masts) during pregnancy. Case-control study. Cancer registry and national birth register data in Great Britain. 1397 cases of cancer in children aged 0-4 from national cancer registry 1999-2001 and 5588 birth controls from national birth register, individually matched by sex and date of birth (four controls per case). Incidence of cancers of the brain and central nervous system, leukaemia, and non-Hodgkin's lymphomas, and all cancers combined, adjusted for small area measures of education level, socioeconomic deprivation, population density, and population mixing. Mean distance of registered address at birth from a macrocell base station, based on a national database of 76,890 base station antennas in 1996-2001, was similar for cases and controls (1107 (SD 1131) m v 1073 (SD 1130) m, P=0.31), as was total power output of base stations within 700 m of the address (2.89 (SD 5.9) kW v 3.00 (SD 6.0) kW, P=0.54) and modelled power density (-30.3 (SD 21.7) dBm v -29.7 (SD 21.5) dBm, P=0.41). For modelled power density at the address at birth, compared with the lowest exposure category the adjusted odds ratios were 1.01 (95% confidence interval 0.87 to 1.18) in the intermediate and 1.02 (0.88 to 1.20) in the highest exposure category for all cancers (P=0.79 for trend), 0.97 (0.69 to 1.37) and 0.76 (0.51 to 1.12), respectively, for brain and central nervous system cancers (P=0.33 for trend), and 1.16 (0.90 to 1.48) and 1.03 (0.79 to 1.34) for leukaemia and non-Hodgkin's lymphoma (P=0.51 for trend). There is no association between risk of early childhood cancers and estimates of the mother's exposure to mobile phone base stations during pregnancy.

A study of El Niño-Southern oscillation impacts to the South China Sea region using ground-based GPS receiver

International Nuclear Information System (INIS)

Suparta, Wayan; Iskandar, Ahmad; Singh, Mandeep Singh Jit; Ali, Mohd Alauddin Mohd; Yatim, Baharudin; Tangang, Fredolin

2013-01-01

We observe an ENSO activity by using ground-based GPS receiver as an effort to study the effects of global warming and climate change in the tropical region. The precipitable water vapor (PWV) derived from Global Positioning System (GPS) meteorology in line with the sea surface temperature anomaly (SSTa) is used to indicate their response on ENSO activities. The PWV data used in this study was taken from the station at Universiti Malaysia Sabah, Kota Kinabalu (UMSK) over 2011, together with NTUS station (in the Singapore), PIMO (in Philippines) and BAKO (in Indonesia) are also compared. The relationship between PWV and SSTa at all stations on weekly basis exhibited modest with correlation coefficients between −0.30 and −0.78 significantly at the 99% confidence level. The negative correlation indicates that during a La Niña phase, the PWV is increased when the sea surface temperatures getting cold causes warm air mass in the central Pacific moved to west Pacific. The increased of PWV causes the GPS signals will be getting slower.

A study of El Niño-Southern oscillation impacts to the South China Sea region using ground-based GPS receiver

Science.gov (United States)

Suparta, Wayan; Iskandar, Ahmad; Singh Jit Singh, Mandeep; Alauddin Mohd Ali, Mohd; Yatim, Baharudin; Tangang, Fredolin

2013-04-01

We observe an ENSO activity by using ground-based GPS receiver as an effort to study the effects of global warming and climate change in the tropical region. The precipitable water vapor (PWV) derived from Global Positioning System (GPS) meteorology in line with the sea surface temperature anomaly (SSTa) is used to indicate their response on ENSO activities. The PWV data used in this study was taken from the station at Universiti Malaysia Sabah, Kota Kinabalu (UMSK) over 2011, together with NTUS station (in the Singapore), PIMO (in Philippines) and BAKO (in Indonesia) are also compared. The relationship between PWV and SSTa at all stations on weekly basis exhibited modest with correlation coefficients between -0.30 and -0.78 significantly at the 99% confidence level. The negative correlation indicates that during a La Niña phase, the PWV is increased when the sea surface temperatures getting cold causes warm air mass in the central Pacific moved to west Pacific. The increased of PWV causes the GPS signals will be getting slower.

Foundation Investigation for Ground Based Radar Project-Kwajalein Island, Marshall Islands

Science.gov (United States)

1990-04-01

iL_ COPY MISCELLANEOUS PAPER GL-90-5 i iFOUNDATION INVESTIGATION FOR GROUND BASED RADAR PROJECT--KWAJALEIN ISLAND, MARSHALL ISLANDS by Donald E...C!assification) Foundatioa Investigation for Ground Based Radar Project -- Kwajalein Island, Marshall Islands 12. PERSONAL AUTHOR(S) Yule, Donald E...investigation for the Ground Based Radar Project -- Kwajalein Island, Marshall Islands , are presented.- eophysical tests comprised of surface refrac- tion

Impact of Base Station Cooperation on Cell Planning

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Ian Dexter Garcia

2010-01-01

Full Text Available Base station cooperation (BSC has been identified as a key radio access technology for next-generation cellular networks such as LTE-Advanced. BSC impacts cell planning, which is the methodical selection of base station (BS sites, and BS equipment configuration for cost-effective cellular networks. In this paper, the impact of BSC on cell plan parameters (coverage, traffic, handover, and cost, as well as additional cell planning steps required for BSC are discussed. Results show that BSC maximizes its gains over noncooperation (NC in a network wherein interference from cooperating BSs is the main limitation. Locations exist where NC may produce higher throughputs, therefore dynamic or semistatic switching between BSC and NC, called fractional BSC, is recommended. Because of interference from noncooperating BSs, the gains of BSC over NC are upper bounded, and diminishes at greater intersite distances because of noise. This encourages smaller cell sizes, higher transmit powers, and dynamic clustering of cooperative BSs.

EME assessments using telstra's mobile base station field intensity plotter

International Nuclear Information System (INIS)

Wood, M.; Hurren, S.; Vinnal, E.; Armstrong, M.

2001-01-01

Public interest in the potential health issues arising from mobile phone base stations has highlighted the importance of having accessible and easy to understand information on electromagnetic energy (EME) emission levels. A range of groups including residents, community groups, businesses, schools, site owners and local governments are often interested in knowing what EME levels a particular base station is capable of producing and how these compare to safety standards regulated by the Australian Communications Authority (ACA). Performing the complex mathematical calculations to predict these levels requires significant expertise, is time consuming and relatively costly. A new software tool, born out of Telstra's EME Research and Development Program, is set to revolutionise EME assessments by facilitating the provision of this information in a more timely, standardised and cost effective manner. Telstra has taken the decision to commercialise the software, which is a world first, because of expressions of interest from other carriers, EME assessment specialists, government agencies and regulatory organisations both in Australia and overseas. Significantly, the software should improve the flow of easy to understand and accurate information on emission levels from base stations. Copyright (2001) Australasian Radiation Protection Society Inc

Evaluation of stability of foundation ground during earthquake, (5)

International Nuclear Information System (INIS)

Nishi, Koh-ichi; Kanatani, Mamoru

1987-01-01

The Central Research Institute of Electric Power Industry advances the research on the method of evaluating foundation grounds from the standpoint of developing in-situ ground survey testing method and the method of evaluating mechanical properties in the studies on the technology for siting nuclear power stations on Quaternary grounds. The newly developed analytical technique on ground stability by the results of the analytical method for equivalent linear response was already reported. In this paper, the analytical method for nonlinear response to investigate into the more detailed behavior of ground due to strong earthquake motion is reported. In particular, the constitutive relation based on elastoplasticity was newly proposed in order to represent the deformation behavior during cyclic loading, and the examples of its application to the response of horizontally leveled sandy ground to earthquake are described. The dialatancy characteristics of soil are constituted by yield function, plastic potential functioin and hardening function. The material constants in proposed constitutive relation are easily determined by laboratory tests. One-dimensional response analysis was conducted, using the constitutive relation. (Kako, I.)

Assessment of radiofrequency/microwave radiation emitted by the antennas of rooftop-mounted mobile phone base stations

International Nuclear Information System (INIS)

Keow, M. A.; Radiman, S.

2006-01-01

Radiofrequency (RF) and microwave (MW) radiation exposures from the antennas of rooftop-mounted mobile telephone base stations have become a serious issue in recent years due to the rapidly evolving technologies in wireless telecommunication systems. In Malaysia, thousands of mobile telephone base stations have been erected all over the country, most of which are mounted on the rooftops. In view of public concerns, measurements of the RF/MW levels emitted by the base stations were carried out in this study. The values were compared with the exposure limits set by several organisations and countries. Measurements were performed at 200 sites around 47 mobile phone base stations. It was found that the RF/MW radiation from these base stations were well below the maximum exposure limits set by various agencies. (authors)

Smos Land Product Validation Activities at the Valencia Anchor Station

Science.gov (United States)

Lopez-Baeza, Ernesto

ABSTRACT Soil moisture is a key parameter controlling the exchanges between the land surface and the atmosphere. In spite of being important for weather and climate modeling, this parameter is not well observed at a global scale. The SMOS (Soil Moisture and Ocean Salinity) Mission was designed by the European Space Agency (ESA) to measure soil moisture over continental surfaces as well as surface salinity over the oceans. Since 2001, the Valencia Anchor Station is currently being prepared for the validation of SMOS land products, namely soil moisture content and vegetation water content. The site has recently been selected by the Mission as a core validation site, mainly due to the reasonable homogeneous characteristics of the area which make it appropriate to undertake the validation of SMOS Level 2 land products during the Mission Commissioning Phase, before attempting more complex areas. Close to SMOS launch, ESA has defined and designed a SMOS V alidation Rehearsal C ampaign P lan which purpose is to repeat the Commissioning Phase execution with all centers, all tools, all participants, all structures, all data available, assuming all tools and structures are ready and trying to produce as close as possible the post-launch conditions. The aim is to test the readiness, the ensemble coordination and the speed of operations, and to avoid as far as possible any unexpected deficiencies of the plan and procedure during the real C ommissioning P hase campaigns. For the rehearsal activity, a control area of 10 x 10 km2 has been chosen at the Valencia Anchor Station study area where a network of ground soil moisture measuring stations is being set up based on the definition of homogeneous physio-hydrological units, attending to climatic, soil type, lithology, geology, elevation, slope and vegetation cover conditions. These stations are linked via a wireless communication system to a master post accessible via internet. The ground soil moisture stations will also be used

Design of a base station for MEMS CCR localization in an optical sensor network.

Science.gov (United States)

Park, Chan Gook; Jeon, Hyun Cheol; Kim, Hyoun Jin; Kim, Jae Yoon

2014-05-08

This paper introduces a design and implementation of a base station, capable of positioning sensor nodes using an optical scheme. The base station consists of a pulse laser module, optical detectors and beam splitter, which are mounted on a rotation-stage, and a Time to Digital Converter (TDC). The optical pulse signal transmitted to the sensor node with a Corner Cube Retro-reflector (CCR) is reflected to the base station, and the Time of Flight (ToF) data can be obtained from the two detectors. With the angle and flight time data, the position of the sensor node can be calculated. The performance of the system is evaluated by using a commercial CCR. The sensor nodes are placed at different angles from the base station and scanned using the laser. We analyze the node position error caused by the rotation and propose error compensation methods, namely the outlier sample exception and decreasing the confidence factor steadily using the recursive least square (RLS) methods. Based on the commercial CCR results, the MEMS CCR is also tested to demonstrate the compatibility between the base station and the proposed methods. The result shows that the localization performance of the system can be enhanced with the proposed compensation method using the MEMS CCR.

Design of a Base Station for MEMS CCR Localization in an Optical Sensor Network

Directory of Open Access Journals (Sweden)

Chan Gook Park

2014-05-01

Full Text Available This paper introduces a design and implementation of a base station, capable of positioning sensor nodes using an optical scheme. The base station consists of a pulse laser module, optical detectors and beam splitter, which are mounted on a rotation-stage, and a Time to Digital Converter (TDC. The optical pulse signal transmitted to the sensor node with a Corner Cube Retro-reflector (CCR is reflected to the base station, and the Time of Flight (ToF data can be obtained from the two detectors. With the angle and flight time data, the position of the sensor node can be calculated. The performance of the system is evaluated by using a commercial CCR. The sensor nodes are placed at different angles from the base station and scanned using the laser. We analyze the node position error caused by the rotation and propose error compensation methods, namely the outlier sample exception and decreasing the confidence factor steadily using the recursive least square (RLS methods. Based on the commercial CCR results, the MEMS CCR is also tested to demonstrate the compatibility between the base station and the proposed methods. The result shows that the localization performance of the system can be enhanced with the proposed compensation method using the MEMS CCR.

Method for analysis the complex grounding cables system

International Nuclear Information System (INIS)

Ackovski, R.; Acevski, N.

2002-01-01

A new iterative method for the analysis of the performances of the complex grounding systems (GS) in underground cable power networks with coated and/or uncoated metal sheathed cables is proposed in this paper. The analyzed grounding system consists of the grounding grid of a high voltage (HV) supplying transformer station (TS), middle voltage/low voltage (MV/LV) consumer TSs and arbitrary number of power cables, connecting them. The derived method takes into consideration the drops of voltage in the cable sheets and the mutual influence among all earthing electrodes, due to the resistive coupling through the soil. By means of the presented method it is possible to calculate the main grounding system performances, such as earth electrode potentials under short circuit fault to ground conditions, earth fault current distribution in the whole complex grounding system, step and touch voltages in the nearness of the earthing electrodes dissipating the fault current in the earth, impedances (resistances) to ground of all possible fault locations, apparent shield impedances to ground of all power cables, e.t.c. The proposed method is based on the admittance summation method [1] and is appropriately extended, so that it takes into account resistive coupling between the elements that the GS. (Author)

Space Station Engineering and Technology Development. Proceedings of the Panel on Program Performance and Onboard Mission Control

Science.gov (United States)

1985-01-01

An ad-hoc committee was asked to review the following questions relevant to the space station program: (1) onboard maintainability and repair; (2) in-space research and technology program and facility plans; (3) solar thermodynamic research and technology development program planning; (4) program performance (cost estimating, management, and cost avoidance); (5) onboard versus ground-based mission control; and (6) technology development road maps from IOC to the growth station. The objective of these new assignments is to provide NASA with advice on ways and means for improving the content, performance, and/or effectiveness of these elements of the space station program.

Modular space station, phase B extension. Program operations plan

Science.gov (United States)

1971-01-01

An organized approach is defined for establishing the most significant requirements pertaining to mission operations, information management, and computer program design and development for the modular space station program. The operations plan pertains to the space station and experiment module program elements and to the ground elements required for mission management and mission support operations.

Magnetic field measurements near stand-alone transformer stations.

Science.gov (United States)

Kandel, Shaiela; Hareuveny, Ronen; Yitzhak, Nir-Mordechay; Ruppin, Raphael

2013-12-01

Extremely low-frequency (ELF) magnetic field (MF) measurements around and above three stand-alone 22/0.4-kV transformer stations have been performed. The low-voltage (LV) cables between the transformer and the LV switchgear were found to be the major source of strong ELF MFs of limited spatial extent. The strong fields measured above the transformer stations support the assessment method, to be used in future epidemiological studies, of classifying apartments located right above the transformer stations as highly exposed to MFs. The results of the MF measurements above the ground around the transformer stations provide a basis for the assessment of the option of implementing precautionary procedures.

A Pseudorange Measurement Scheme Based on Snapshot for Base Station Positioning Receivers.

Science.gov (United States)

Mo, Jun; Deng, Zhongliang; Jia, Buyun; Bian, Xinmei

2017-12-01

Digital multimedia broadcasting signal is promised to be a wireless positioning signal. This paper mainly studies a multimedia broadcasting technology, named China mobile multimedia broadcasting (CMMB), in the context of positioning. Theoretical and practical analysis on the CMMB signal suggests that the existing CMMB signal does not have the meter positioning capability. So, the CMMB system has been modified to achieve meter positioning capability by multiplexing the CMMB signal and pseudo codes in the same frequency band. The time difference of arrival (TDOA) estimation method is used in base station positioning receivers. Due to the influence of a complex fading channel and the limited bandwidth of receivers, the regular tracking method based on pseudo code ranging is difficult to provide continuous and accurate TDOA estimations. A pseudorange measurement scheme based on snapshot is proposed to solve the problem. This algorithm extracts the TDOA estimation from the stored signal fragments, and utilizes the Taylor expansion of the autocorrelation function to improve the TDOA estimation accuracy. Monte Carlo simulations and real data tests show that the proposed algorithm can significantly reduce the TDOA estimation error for base station positioning receivers, and then the modified CMMB system achieves meter positioning accuracy.

Experimental research of variable rotation speed ICE-based electric power station

Directory of Open Access Journals (Sweden)

Dar’enkov Andrey

2017-01-01

Full Text Available Developing variable rotation speed ICE-based stand-alone electric power stations which can supply distant regions and autonomous objects with electricity are of scientific interest due to the insufficient study. The relevance of developing such electric power stations is determined by their usage is to provide a significant fuel saving as well as increase ICE motor service life. The article describes the electric station of autonomous objects with improved fuel economy. The article describes multivariate characteristic. Multivariate characteristic shows the optimal frequency of rotation of the internal combustion engine. At this rotational speed there is the greatest fuel economy.

Improving correlations between MODIS aerosol optical thickness and ground-based PM 2.5 observations through 3D spatial analyses

Science.gov (United States)

Hutchison, Keith D.; Faruqui, Shazia J.; Smith, Solar

The Center for Space Research (CSR) continues to focus on developing methods to improve correlations between satellite-based aerosol optical thickness (AOT) values and ground-based, air pollution observations made at continuous ambient monitoring sites (CAMS) operated by the Texas commission on environmental quality (TCEQ). Strong correlations and improved understanding of the relationships between satellite and ground observations are needed to formulate reliable real-time predictions of air quality using data accessed from the moderate resolution imaging spectroradiometer (MODIS) at the CSR direct-broadcast ground station. In this paper, improvements in these correlations are demonstrated first as a result of the evolution in the MODIS retrieval algorithms. Further improvement is then shown using procedures that compensate for differences in horizontal spatial scales between the nominal 10-km MODIS AOT products and CAMS point measurements. Finally, airborne light detection and ranging (lidar) observations, collected during the Texas Air Quality Study of 2000, are used to examine aerosol profile concentrations, which may vary greatly between aerosol classes as a result of the sources, chemical composition, and meteorological conditions that govern transport processes. Further improvement in correlations is demonstrated with this limited dataset using insights into aerosol profile information inferred from the vertical motion vectors in a trajectory-based forecast model. Analyses are ongoing to verify these procedures on a variety of aerosol classes using data collected by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (Calipso) lidar.

BigBOSS: The Ground-Based Stage IV BAO Experiment

Energy Technology Data Exchange (ETDEWEB)

Schlegel, David; Bebek, Chris; Heetderks, Henry; Ho, Shirley; Lampton, Michael; Levi, Michael; Mostek, Nick; Padmanabhan, Nikhil; Perlmutter, Saul; Roe, Natalie; Sholl, Michael; Smoot, George; White, Martin; Dey, Arjun; Abraham, Tony; Jannuzi, Buell; Joyce, Dick; Liang, Ming; Merrill, Mike; Olsen, Knut; Salim, Samir

2009-04-01

The BigBOSS experiment is a proposed DOE-NSF Stage IV ground-based dark energy experiment to study baryon acoustic oscillations (BAO) and the growth of structure with an all-sky galaxy redshift survey. The project is designed to unlock the mystery of dark energy using existing ground-based facilities operated by NOAO. A new 4000-fiber R=5000 spectrograph covering a 3-degree diameter field will measure BAO and redshift space distortions in the distribution of galaxies and hydrogen gas spanning redshifts from 0.2< z< 3.5. The Dark Energy Task Force figure of merit (DETF FoM) for this experiment is expected to be equal to that of a JDEM mission for BAO with the lower risk and cost typical of a ground-based experiment.

SOUTH RAMP DEVIATED ALIGNMENT 3.01.X AREA GROUND SUPPORT ANALYSIS (STATION 71+07.10 TO 71+44.10)

International Nuclear Information System (INIS)

M.J. Mrugala

2000-01-01

The purpose of the analysis is to provide a basis for ensuring safe conditions in the Case VI area. The scope of this analysis is to analyze and recommend future action for a section of the South Ramp with a deviated alignment, here referred to as Case VI 3.01.X area. This area is located between Stations 71+07.10 to 71+44.10 in the South Ramp of the ESF (Exploratory Studies Facility) Main Loop tunnel. The scope of the analysis includes accomplishing the following goals: (1) Document the as-built configuration including existing voids and installed ground support; (2) Document the geotechnical properties of the rock mass and structural features; and (3) Evaluate the stability and develop recommendations for future action

Optimization and Feasibility Analysis of Satellite Earth Station Power System Using Homer

Directory of Open Access Journals (Sweden)

Hassen T. Dorrah

2012-06-01

Full Text Available Satellite earth stations which located in remote areas are one of many applications powered by the renewable energy sources. Ground system consists of ground station and control centers working together to support the spacecraft and the data user. Earth station consists of major subsystems, transmitter, receiver, antenna, tracking equipment, terrestrial interface equipment and power supply. Power subsystem is an important part that required for supplying the earth station with electrical power to continue communicating with its remote sensing satellite. This paper deals with simulation and optimal sizing of earth station power system using HOMER software. A combination of two energy sources (solar, and wind to provide a continuous electric power production is used to determine the optimum system operation. Three system configurations are compared with respect to the total net present cost (NPC and levelized cost of energy (COE. Also, economical study will be analyzed for energy demand and sensitivity analysis will be performed.

Ground-water contamination at Wurtsmith Air Force Base, Michigan

Science.gov (United States)

Stark, J.R.; Cummings, T.R.; Twenter, F.R.

1983-01-01

A sand and gravel aquifer of glacial origin underlies Wurtsmith Air Force Base in northeastern lower Michigan. The aquifer overlies a thick clay layer at an average depth of 65 feet. The water table is about 10 feet below land surface in the western part of the Base and about 25 feet below land surface in the eastern part. A ground-water divide cuts diagonally across the Base from northwest to southeast. South of the divide, ground water flows to the Au Sable River; north of the divide, it flows to Van Etten Creek and Van Etten Lake. Mathematical models were used to aid in calculating rates of groundwater flow. Rates range from about 0.8 feet per day in the eastern part of the Base to about 0.3 feet per day in the western part. Models also were used as an aid in making decisions regarding purging of contaminated water from the aquifer. In 1977, trichloroethylene was detected in the Air Force Base water-supply system. It had leaked from a buried storage tank near Building 43 in the southeastern part of the Base and moved northeastward under the influence of the natural ground-water gradient and the pumping of Base water-supply wells. In the most highly contaminated part of the plume, concentrations are greater than 1,000 micrograms per liter. Current purge pumping is removing some of the trichloroethylene, and seems to have arrested its eastward movement. Pumping of additional purge wells could increase the rate of removal. Trichloroethylene has also been detected in ground water in the vicinity of the Base alert apron, where a plume from an unknown source extends northeastward off Base. A smaller, less well-defined area of contamination also occurs just north of the larger plume. Trichloroethylene, identified near the waste-treatment plant, seepage lagoons, and the northern landfill area, is related to activities and operations in these areas. Dichloroethylene and trichloroethylene occur in significant quantities westward of Building 43, upgradient from the major

Applications of power beaming from space-based nuclear power stations. [Laser beaming to airplanes; microwave beaming to ground

Energy Technology Data Exchange (ETDEWEB)

Powell, J.R.; Botts, T.E.; Hertzberg, A.

1981-01-01

Power beaming from space-based reactor systems is examined using an advanced compact, lightweight Rotating Bed Reactor (RBR). Closed Brayton power conversion efficiencies in the range of 30 to 40% can be achieved with turbines, with reactor exit temperatures on the order of 2000/sup 0/K and a liquid drop radiator to reject heat at temperatures of approx. 500/sup 0/K. Higher RBR coolant temperatures (up to approx. 3000/sup 0/K) are possible, but gains in power conversion efficiency are minimal, due to lower expander efficiency (e.g., a MHD generator). Two power beaming applications are examined - laser beaming to airplanes and microwave beaming to fixed ground receivers. Use of the RBR greatly reduces system weight and cost, as compared to solar power sources. Payback times are a few years at present prices for power and airplane fuel.

Radiation Measurement from Mobile Base Stations at a University Campus in Malaysia

OpenAIRE

Md. R. Islam; Othman O. Khalifa; Liakot Ali; Amir Azli; Mohd Zulkarnain

2006-01-01

The tremendous growth of telecommunication industry results the number of hand phone users increases everyday. In order to support the growing number of users, the mobile base stations can be seen in almost everywhere. This scenario has created uncomfortable feelings to the people that they may be affected by the radiations from antennas. A measurement was done at student hostels and office premises near to base stations in International Islamic University Malaysia, Gombak campus. Measured va...

Statistical analysis of electromagnetic radiation measurements in the vicinity of GSM/UMTS base station antenna masts.

Science.gov (United States)

Koprivica, Mladen; Neskovic, Natasa; Neskovic, Aleksandar; Paunovic, George

2014-01-01

As a result of dense installations of public mobile base station, additional electromagnetic radiation occurs in the living environment. In order to determine the level of radio-frequency radiation generated by base stations, extensive electromagnetic field strength measurements were carried out for 664 base station locations. Base station locations were classified into three categories: indoor, masts and locations with installations on buildings. Having in mind the large percentage (47 %) of sites with antenna masts, a detailed analysis of this location category was performed, and the measurement results were presented. It was concluded that the total electric field strength in the vicinity of base station antenna masts in no case exceeded 10 V m(-1), which is quite below the International Commission on Non-Ionizing Radiation Protection reference levels. At horizontal distances >50 m from the mast bottom, the median and maximum values were <1 and 2 V m(-1), respectively.

Statistical analysis of electromagnetic radiation measurements in the vicinity of GSM/UMTS base station antenna masts

International Nuclear Information System (INIS)

Koprivica, M.; Neskovic, N.; Neskovic, A.; Paunovic, G.

2014-01-01

As a result of dense installations of public mobile base station, additional electromagnetic radiation occurs in the living environment. In order to determine the level of radio-frequency radiation generated by base stations, extensive electromagnetic field strength measurements were carried out for 664 base station locations. Base station locations were classified into three categories: indoor, masts and locations with installations on buildings. Having in mind the large percentage (47 %) of sites with antenna masts, a detailed analysis of this location category was performed, and the measurement results were presented. It was concluded that the total electric field strength in the vicinity of base station antenna masts in no case exceeded 10 V m -1 , which is quite below the International Commission on Non-Ionizing Radiation Protection reference levels. At horizontal distances >50 m from the mast bottom, the median and maximum values were -1 , respectively. (authors)

Lunar base mission technology issues and orbital demonstration requirements on space station

Science.gov (United States)

Llewellyn, Charles P.; Weidman, Deene J.

1992-01-01

The International Space Station has been the object of considerable design, redesign, and alteration since it was originally proposed in early 1984. In the intervening years the station has slowly evolved to a specific design that was thoroughly reviewed by a large agency-wide Critical Evaluation Task Force (CETF). As space station designs continue to evolve, studies must be conducted to determine the suitability of the current design for some of the primary purposes for which the station will be used. This paper concentrates on the technology requirements and issues, the on-orbit demonstration and verification program, and the space station focused support required prior to the establishment of a permanently manned lunar base as identified in the National Commission on Space report. Technology issues associated with the on-orbit assembly and processing of the lunar vehicle flight elements are also discussed.

A modular Space Station/Base electrical power system - Requirements and design study.

Science.gov (United States)

Eliason, J. T.; Adkisson, W. B.

1972-01-01

The requirements and procedures necessary for definition and specification of an electrical power system (EPS) for the future space station are discussed herein. The considered space station EPS consists of a replaceable main power module with self-contained auxiliary power, guidance, control, and communication subsystems. This independent power source may 'plug into' a space station module which has its own electrical distribution, control, power conditioning, and auxiliary power subsystems. Integration problems are discussed, and a transmission system selected with local floor-by-floor power conditioning and distribution in the station module. This technique eliminates the need for an immediate long range decision on the ultimate space base power sources by providing capability for almost any currently considered option.

47 CFR 0.434 - Data bases and lists of authorized broadcast stations and pending broadcast applications.

Science.gov (United States)

2010-10-01

... stations and pending broadcast applications. 0.434 Section 0.434 Telecommunication FEDERAL COMMUNICATIONS... Commission § 0.434 Data bases and lists of authorized broadcast stations and pending broadcast applications... broadcast stations, pending applications for such stations, and rulemaking proceedings involving amendments...

Airborne relay-based regional positioning system.

Science.gov (United States)

Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

2015-05-28

Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations.

Automatic Classification of Station Quality by Image Based Pattern Recognition of Ppsd Plots

Science.gov (United States)

Weber, B.; Herrnkind, S.

2017-12-01

The number of seismic stations is growing and it became common practice to share station waveform data in real-time with the main data centers as IRIS, GEOFON, ORFEUS and RESIF. This made analyzing station performance of increasing importance for automatic real-time processing and station selection. The value of a station depends on different factors as quality and quantity of the data, location of the site and general station density in the surrounding area and finally the type of application it can be used for. The approach described by McNamara and Boaz (2006) became standard in the last decade. It incorporates a probability density function (PDF) to display the distribution of seismic power spectral density (PSD). The low noise model (LNM) and high noise model (HNM) introduced by Peterson (1993) are also displayed in the PPSD plots introduced by McNamara and Boaz allowing an estimation of the station quality. Here we describe how we established an automatic station quality classification module using image based pattern recognition on PPSD plots. The plots were split into 4 bands: short-period characteristics (0.1-0.8 s), body wave characteristics (0.8-5 s), microseismic characteristics (5-12 s) and long-period characteristics (12-100 s). The module sqeval connects to a SeedLink server, checks available stations, requests PPSD plots through the Mustang service from IRIS or PQLX/SQLX or from GIS (gempa Image Server), a module to generate different kind of images as trace plots, map plots, helicorder plots or PPSD plots. It compares the image based quality patterns for the different period bands with the retrieved PPSD plot. The quality of a station is divided into 5 classes for each of the 4 bands. Classes A, B, C, D define regular quality between LNM and HNM while the fifth class represents out of order stations with gain problems, missing data etc. Over all period bands about 100 different patterns are required to classify most of the stations available on the

The southern ozone hole as observed at Belgrano station

OpenAIRE

SILBERGLEIT, VIRGINIA

2000-01-01

The thinning of the stratosphere ozone layer in the Antarctic region is studied by considering ground-based observations at Belgrano Station (78.0°S; 38.8°W). Gumbel's first distribution of extreme values is used to evaluate the highest depletion of the Southern ozone hole for the spring months of 1998. According to the present study we predict that the expected largest yearly deviation of the ozone layer density during 1998 would be (109 ± 15)DU. This result agrees remarkably well with the m...

Space Station data management system architecture

Science.gov (United States)

Mallary, William E.; Whitelaw, Virginia A.

1987-01-01

Within the Space Station program, the Data Management System (DMS) functions in a dual role. First, it provides the hardware resources and software services which support the data processing, data communications, and data storage functions of the onboard subsystems and payloads. Second, it functions as an integrating entity which provides a common operating environment and human-machine interface for the operation and control of the orbiting Space Station systems and payloads by both the crew and the ground operators. This paper discusses the evolution and derivation of the requirements and issues which have had significant effect on the design of the Space Station DMS, describes the DMS components and services which support system and payload operations, and presents the current architectural view of the system as it exists in October 1986; one-and-a-half years into the Space Station Phase B Definition and Preliminary Design Study.

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...

DETERMINING UNDISTURBED GROUND TEMPERATURE AS PART OF SHALLOW GEOTHERMAL RESOURCES ASSESSMENT

Directory of Open Access Journals (Sweden)

Tomislav Kurevija

2010-12-01

Full Text Available The undisturbed ground temperature is one of the key thermogeological parameters for the assessment and utilization of shallow geothermal resources. Geothermal energy is the type of energy which is stored in the ground where solar radiation has no effect. The depth at which the undisturbed ground temperature occurs, independent of seasonal changes in the surface air temperature, is functionally determined by climate parameters and thermogeological properties. In deeper layers, the increase of ground temperature depends solely on geothermal gradient. Determining accurate values of undisturbed ground temperature and depth of occurrence is crucial for the correct sizing of a borehole heat exchanger as part of the ground-source heat pump system, which is considered the most efficient technology for utilising shallow geothermal resources. The purpose of this paper is to define three specific temperature regions, based on the measured ground temperature data collected from the main meteorological stations in Croatia. The three regions are: Northern Croatia, Adriatic region, and the regions of Lika and Gorski Kotar.

New Applications for Detecting Natural Hazards Using Ground and Space-Based GNSS-Derived Ionospheric Measurements

Science.gov (United States)

Komjathy, A.; Butala, M.; Verkhoglyadova, O. P.; Wilson, B. D.; Iijima, B.; Akopian, V.; Mannucci, A.

2012-12-01

The NASA Jet Propulsion Laboratory (JPL) and University of Southern California (USC) have jointly developed the Global Assimilative Ionospheric Model (GAIM) to monitor space weather, study storm effects, and provide ionospheric calibration for various customers including NASA flight projects. JPL/USC GAIM is a physics-based 3D data assimilation model using 4DVAR and Kalman filter approaches to solve for ion and electron density states and other key ionospheric drivers. The JPL/USC GAIM technologies, now operating in real-time and post-processing modes, can routinely accept as input ground GPS TEC data from 1200+ sites including streaming and hourly GPS stations, occultation links from CHAMP, SAC-C, COSMIC and C/NOFS satellites, UV limb and nadir scans. In the presentation, first we will discuss recent advances in our assimilating ground-based GPS, C/NOFS and COSMIC occultation measurements using our GAIM system characterizing the ionosphere in 3D. We will elaborate on our improved space-based bias estimation techniques to generate high precision calibrated TEC measurements to be assimilated into GAIM. We will discuss the benefits of adding GLONASS measurements to our GIM and GAIM processing technologies. New and upcoming applications and first results will be shown for estimating very high precision TEC perturbations using real-time and post-processed GNSS observations from GEONET and IGS networks. We will demonstrate initial steps on how to integrate this GNSS ionosphere-based technology into a global tsunami warning system. Additional potential applications might include the remote sensing of ionospheric TEC perturbations generated by other natural hazards such as earthquakes and volcanic eruptions and human-made events such as nuclear tests.

Experiments Using a Ground-Based Electrostatic Levitator and Numerical Modeling of Melt Convection for the Iron-Cobalt System in Support of Space Experiments

Science.gov (United States)

Lee, Jonghyun; SanSoucie, Michael P.

2017-08-01

Materials research is being conducted using an electromagnetic levitator installed in the International Space Station. Various metallic alloys were tested to elucidate unknown links among the structures, processes, and properties. To accomplish the mission of these space experiments, several ground-based activities have been carried out. This article presents some of our ground-based supporting experiments and numerical modeling efforts. Mass evaporation of Fe50Co50, one of flight compositions, was predicted numerically and validated by the tests using an electrostatic levitator (ESL). The density of various compositions within the Fe-Co system was measured with ESL. These results are being served as reference data for the space experiments. The convection inside a electromagnetically-levitated droplet was also modeled to predict the flow status, shear rate, and convection velocity under various process parameters, which is essential information for designing and analyzing the space experiments of some flight compositions influenced by convection.

Study of the active layer at the Spanish Antarctic station “Gabriel de Castilla”, Deception Island, Antarctica; Análisis del estado de la capa activa en el emplazamiento de la base antártica española Gabriel de Castilla, Isla Decepción, Antártida.

Energy Technology Data Exchange (ETDEWEB)

Pablo, M.A. de; Molina, A.; Recio, C.; Ramos, M.; Goyanes, G.; Ropero, M.A.

2017-09-01

The degradation of permanent frozen ground (permafrost) and the increase in the thickness of the active layer may be caused both by natural processes (such as global climate change) and by anthropic activity, which changes the natural environmental conditions that allow its existence, as has been widely reported to occur in the northern polar and subpolar regions. In the case of Antarctica, some scientific research stations are located in areas with permafrost, such as the Spanish Antarctic station “Gabriel de Castilla” on Deception Island. In the place where the station is located, an important increase in erosion has been observed in recent years, including the excavation of new gullies and the erosion of the coastal cliffs. In order to develop an initial analysis of the possible effects of the station on the permafrost degradation, ground temperature has been monitored since 2012 and the thickness and of the active layer and the temperature, both inside and beneath the station, have also been sporadically measured. Here we show the results and discuss how the station reduces the freezing of the ground during the winter when the station is closed and facilitates the warming of the ground during the living periods of the station in the Antarctic summer. Those initial results and conclusions make necessary to continue the study of the permafrost and the active layer in the station site by systematic monitoring of the ground temperature and the thickness of the active layer. [Spanish] La degradación de los suelos congelados (permafrost) y el aumento de espesor de la capa activa pueden deberse tanto a factores naturales, como antrópicos (edificaciones, carreteras, cimentaciones, etc.) que modifican las condiciones naturales y, por tanto, sus características termo-mecánicas, tal y como ha sido profusamente estudiado en el hemisferio Norte. En el caso de la Antártida, algunas bases se encuentran en zonas de permafrost, como es el caso de la base espa

Operation feedback of hydrogen filling station

International Nuclear Information System (INIS)

Pregassame, S.; Barral, K.; Allidieres, L.; Charbonneau, T.; Lacombe, Y.

2004-01-01

One of the technical challenges of hydrogen technology is the development of hydrogen infrastructures which satisfy either safety requirements and reliability of filling processes. AIR LIQUIDE realized an hydrogen filling station in Sassenage (France) operational since September 2003. This station is able to fill 3 buses a day up to 350bar by equilibrium with high pressure buffers. In parallel with commercial stations, the group wanted to create a testing ground in real conditions running with several objectives: validate on a full scale bench a simulation tool able to predict the temperature of both gas and cylinder's materials during filling processes; define the best filling procedures in order to reach mass, temperature and filling time targets; analyse the temperature distribution and evolution inside the cylinder; get a general knowledge about hydrogen stations from safety and reliability point of view; operate the first full scale refuelling station in France. The station is also up-graded for 700bar filling from either a liquid hydrogen source or a gas booster, with cold filling possibility. This paper presents the results concerning 350bar filling : thermal effects, optimal filling procedures and influence of parameters such as climatic conditions are discussed. (author)

Statistical analysis of electromagnetic radiation measurements in the vicinity of indoor microcell GSM/UMTS base stations in Serbia.

Science.gov (United States)

Koprivica, Mladen; Petrić, Majda; Nešković, Nataša; Nešković, Aleksandar

2016-01-01

To determine the level of radiofrequency radiation generated by base stations of Global System for Mobile Communications and Universal Mobile Telecommunication System, extensive electromagnetic field strength measurements were carried out in the vicinity of 664 base station locations. These were classified into three categories: indoor, masts, and locations with installations on buildings. Although microcell base stations with antennas installed indoors typically emit less power than outdoor macrocell base stations, the fact that people can be found close to antennas requires exposure originating from these base stations to be carefully considered. Measurement results showed that maximum recorded value of electric field strength exceeded International Commission on Non-Ionizing Radiation Protection reference levels at 7% of indoor base station locations. At the same time, this percentage was much lower in the case of masts and installations on buildings (0% and 2.5%, respectively). © 2015 Wiley Periodicals, Inc.

Observations of magnetohydrodynamic waves on the ground and on a satellite

International Nuclear Information System (INIS)

Lanzerotti, L.J.; Fukunishi, H.; Maclennan, C.G.; Cahill, L.J. Jr.

1976-01-01

A comparison is made of magnetohydrodynamic waves observed near the equator on Explorer 45 and at an array of ground stations in the northern hemisphere and at their conjugate station at Siple, Antartica. The data comparisons strongly support the notion that the observed waves can be considered odd mode standing waves in the magnetosphere. This conclusion has important implications for the interpretation of single-point satellite and/or ground measurements of ULF plasma wave phenomena in the magnetosphere. Further, the data comparisons strongly suggest that the overall ULF (approx.5-30 mHz) power levels are quite similar in the magnetosphere and on the ground, at least during the intervals studied

Aerial radiological survey of the Rancho Seco Nuclear Generating Station, Clay Station, California, 18 January 1980 to 1 February 1980

International Nuclear Information System (INIS)

1980-11-01

An airborne radiological survey of 260 km 2 area centered over the Rancho Seco Nuclear Generating Station was made 18 January through 1 February 1980. Detected radioisotopes and their associated gamma ray exposure rates were consistent with that expected from normal background emitters, except directly over the station. Count rates observed at 90 m altitude were converted to exposure rates at 1 m above the ground and are presented in the form of an isopleth map

The 136 MHZ/400 MHz earth station antenna-noise temperature prediction program for RAE-B

Science.gov (United States)

Taylor, R. E.; Fee, J. J.; Chin, M.

1972-01-01

A simulation study was undertaken to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low noise periods. Antenna noise temperatures will be predicted for selected earth-based ground stations which will support RAE-B. Telemetry data acquisition will be at 400 MHz; tracking support at 136 MHz will be provided by the Goddard Range and Range Rate (RARR) stations. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973.

Fire Stations

Data.gov (United States)

Department of Homeland Security — Fire Stations in the United States Any location where fire fighters are stationed or based out of, or where equipment that such personnel use in carrying out their...

Overview of Boundary Layer Clouds Using Satellite and Ground-Based Measurements

Science.gov (United States)

Xi, B.; Dong, X.; Wu, P.; Qiu, S.

2017-12-01

A comprehensive summary of boundary layer clouds properties based on our few recently studies will be presented. The analyses include the global cloud fractions and cloud macro/micro- physical properties based on satellite measurements using both CERES-MODIS and CloudSat/Caliposo data products,; the annual/seasonal/diurnal variations of stratocumulus clouds over different climate regions (mid-latitude land, mid-latitude ocean, and Arctic region) using DOE ARM ground-based measurements over Southern great plain (SGP), Azores (GRW), and North slope of Alaska (NSA) sites; the impact of environmental conditions to the formation and dissipation process of marine boundary layer clouds over Azores site; characterizing Arctice mixed-phase cloud structure and favorable environmental conditions for the formation/maintainess of mixed-phase clouds over NSA site. Though the presentation has widely spread topics, we will focus on the representation of the ground-based measurements over different climate regions; evaluation of satellite retrieved cloud properties using these ground-based measurements, and understanding the uncertainties of both satellite and ground-based retrievals and measurements.

Evidence of rock slope breathing using ground-based InSAR

Science.gov (United States)

Rouyet, Line; Kristensen, Lene; Derron, Marc-Henri; Michoud, Clément; Blikra, Lars Harald; Jaboyedoff, Michel; Lauknes, Tom Rune

2017-07-01

Ground-Based Interferometric Synthetic Aperture Radar (GB-InSAR) campaigns were performed in summer 2011 and 2012 in the Romsdalen valley (Møre & Romsdal county, western Norway) in order to assess displacements on Mannen/Børa rock slope. Located 1 km northwest, a second GB-InSAR system continuously monitors the large Mannen rockslide. The availability of two GB-InSAR positions creates a wide coverage of the rock slope, including a slight dataset overlap valuable for validation. A phenomenon of rock slope breathing is detected in a remote and hard-to-access area in mid-slope. Millimetric upward displacements are recorded in August 2011. Analysis of 2012 GB-InSAR campaign, combined with the large dataset from the continuous station, shows that the slope is affected by inflation/deflation phenomenon between 5 and 10 mm along the line-of-sight. The pattern is not homogenous in time and inversions of movement have a seasonal recurrence. These seasonal changes are confirmed by satellite InSAR observations and can possibly be caused by hydrogeological variations. In addition, combination of GB-InSAR results, in situ measurements and satellite InSAR analyses contributes to a better overview of movement distribution over the whole area.

Nutritional status assessment in semiclosed environments: ground-based and space flight studies in humans

Science.gov (United States)

Smith, S. M.; Davis-Street, J. E.; Rice, B. L.; Nillen, J. L.; Gillman, P. L.; Block, G.

2001-01-01

Adequate nutrition is critical during long-term spaceflight, as is the ability to easily monitor dietary intake. A comprehensive nutritional status assessment profile was designed for use before, during and after flight. It included assessment of both dietary intake and biochemical markers of nutritional status. A spaceflight food-frequency questionnaire (FFQ) was developed to evaluate intake of key nutrients during spaceflight. The nutritional status assessment protocol was evaluated during two ground-based closed-chamber studies (60 and 91 d; n = 4/study), and was implemented for two astronauts during 4-mo stays on the Mir space station. Ground-based studies indicated that the FFQ, administered daily or weekly, adequately estimated intake of key nutrients. Chamber subjects maintained prechamber energy intake and body weight. Astronauts tended to eat 40--50% of WHO-predicted energy requirements, and lost >10% of preflight body mass. Serum ferritin levels were lower after the chamber stays, despite adequate iron intake. Red blood cell folate concentrations were increased after the chamber studies. Vitamin D stores were decreased by > 40% on chamber egress and after spaceflight. Mir crew members had decreased levels of most nutritional indices, but these are difficult to interpret given the insufficient energy intake and loss of body mass. Spaceflight food systems can provide adequate intake of macronutrients, although, as expected, micronutrient intake is a concern for any closed or semiclosed food system. These data demonstrate the utility and importance of nutritional status assessment during spaceflight and of the FFQ during extended-duration spaceflight.

Determination of exposure due to mobile phone base stations in an epidemiological study

International Nuclear Information System (INIS)

Neitzke, H. P.; Osterhoff, J.; Peklo, K.; Voigt, H.

2007-01-01

To investigate a supposed relationship between exposure by mobile phone base stations and well-being, an epidemiological cross sectional study is carried out within the German Mobile Telecommunication Research Program. In a parallel project, a method for the classification of electromagnetic exposure due to mobile phone base stations has been developed. This is based on the results of measurements of high frequency immissions in the interior of more than 1100 rooms and at outdoor locations, the calculation of the emissions of mobile phone antennas under free space propagation conditions and empirically determined transmission factors for the propagation of electromagnetic waves in different types of residential areas for passage of walls and windows. Standard tests (correlation-test, kappa-test, Bland-Altman-Plot, analysis of sensitivity and specificity) show that the method for computational exposure assessment developed in this project is applicable for a first classification of exposures due to mobile phone base stations in epidemiological studies. (authors)

Types of Lightning Discharges that Abruptly Terminate Enhanced Fluxes of Energetic Radiation and Particles Observed at Ground Level

International Nuclear Information System (INIS)

Chilingarian, A.; Khanikyants, Y.; Pokhsraryan, D.; Soghomonyan, S.; Mareev, E.; Rakov, V.

2017-01-01

We present ground-based measurements of thunderstorm-related enhancements of fluxes of energetic radiation and particles that are abruptly terminated by lightning discharges. All measurements were performed at an altitude of 3200 m above sea level on Mt. Aragats (Armenia). Lightning signatures were recorded using a network of five electric field mills, three of which were placed at the Aragats station, one at the Nor Amberd station (12.8 km from Aragats), and one at the Yerevan station (39 km from Aragats), and a wideband electric field measuring system with a useful frequency bandwidth of 50 Hz to 12 MHZ. It appears that the flux-enhancement termination is associated with close (within 10 km or so of the particle detector) -CGs and normal polarity ICs; that is, with lightning types which reduce the upward-directed electric field below the cloud and, hence, suppress the acceleration of electrons toward the ground. (author)

Investigation of the exposure level of electromagnetic fields produced by mobile telephone base stations

International Nuclear Information System (INIS)

Abukassem, I.; Kharita, M. H.

2010-12-01

The aim of this work is to investigate the real values of microwave level distribution and propagation in the locality around samples of mobile phone base station, and to compare the results with the exposure restriction limits recommenced by the International Commission on Non Ionizing Radiation Protection (ICNIRP). Measurements were performed using special meters for microwaves; the first (Narda SRM-3000) is used for electromagnetic waves frequency spectrum scanning and the second (NARDA) emr 300) determine the level of electric and magnetic fields and the power density of these waves nearby any sort of transmitters. Samples of different kinds of mobile phone base station were chosen to cover important zones of Damascus, and the region around each base station was also scanned in the emission direction and according to accessibility into the studies positions. Results showed that the signal level in all measured points is lower than the ICNIRP restriction level, but for few points the detected microwave level has relatively important values. The signal level inside building situated partially in the emission direction of the base station transmitters decreases stepwise and walls reduce considerably the signal intensity. To realize these kind of field studies in the best way and obtain the maximum profits for all people, the properties and operating system of transmitters used in mobile phone base station must be known, and therefore, it is very important to achieve a transparent collaboration between research laboratory and mobile phone company. (author)

Hanford ground-water data base management guide and user's manual

International Nuclear Information System (INIS)

Mitchell, P.J.; Argo, R.S.; Bradymire, S.L.; Newbill, C.A.

1985-05-01

This management guide and user's manual is a working document for the computerized Hanford Ground-water Data Base maintained by the Geosciences Research and Engineering Department at Pacific Northwest Laboratory for the Hanford Ground-Water Surveillance Program. The program is managed by the Occupational and Environmental Protection Department for the US Department of Energy. The data base is maintained to provide rapid access to data that are rountinely collected from ground-water monitoring wells at the Hanford site. The data include water levels, sample analyses, geologic descriptions and well construction information of over 3000 existing or destroyed wells. These data are used to monitor water quality and for the evaluation of ground-water flow and pollutant transport problems. The management guide gives instructions for maintenance of the data base on the Digital Equipment Corporation PDP 11/70 Computer using the CIRMIS (Comprehensive Information Retrieval and Model Input Sequence) data base management software developed at Pacific Northwest Laboratory. Maintenance activities include inserting, modifying and deleting data, making back-up copies of the data base, and generating tables for annual monitoring reports. The user's guide includes instructions for running programs to retrieve the data in the form of listings of graphical plots. 3 refs

Landsat Data Continuity Mission (LDCM) space to ground mission data architecture

Science.gov (United States)

Nelson, Jack L.; Ames, J.A.; Williams, J.; Patschke, R.; Mott, C.; Joseph, J.; Garon, H.; Mah, G.

2012-01-01

The Landsat Data Continuity Mission (LDCM) is a scientific endeavor to extend the longest continuous multi-spectral imaging record of Earth's land surface. The observatory consists of a spacecraft bus integrated with two imaging instruments; the Operational Land Imager (OLI), built by Ball Aerospace & Technologies Corporation in Boulder, Colorado, and the Thermal Infrared Sensor (TIRS), an in-house instrument built at the Goddard Space Flight Center (GSFC). Both instruments are integrated aboard a fine-pointing, fully redundant, spacecraft bus built by Orbital Sciences Corporation, Gilbert, Arizona. The mission is scheduled for launch in January 2013. This paper will describe the innovative end-to-end approach for efficiently managing high volumes of simultaneous realtime and playback of image and ancillary data from the instruments to the reception at the United States Geological Survey's (USGS) Landsat Ground Network (LGN) and International Cooperator (IC) ground stations. The core enabling capability lies within the spacecraft Command and Data Handling (C&DH) system and Radio Frequency (RF) communications system implementation. Each of these systems uniquely contribute to the efficient processing of high speed image data (up to 265Mbps) from each instrument, and provide virtually error free data delivery to the ground. Onboard methods include a combination of lossless data compression, Consultative Committee for Space Data Systems (CCSDS) data formatting, a file-based/managed Solid State Recorder (SSR), and Low Density Parity Check (LDPC) forward error correction. The 440 Mbps wideband X-Band downlink uses Class 1 CCSDS File Delivery Protocol (CFDP), and an earth coverage antenna to deliver an average of 400 scenes per day to a combination of LGN and IC ground stations. This paper will also describe the integrated capabilities and processes at the LGN ground stations for data reception using adaptive filtering, and the mission operations approach fro- the LDCM

STRUVE arc and EUPOS® stations

Science.gov (United States)

Lasmane, Ieva; Kaminskis, Janis; Balodis, Janis; Haritonova, Diana

2013-04-01

The Struve Geodetic Arc was developed in Years 1816 to 1855, 200 years ago. Historic information on the points of the Struve Geodetic Arc are included in the UNESCO World Heritage list in 2005. Nevertheless, the sites of many points are still not identified nor included in the data bases nowadays. Originally STRUVE arc consisted of 258 main triangles with 265 triangulation points. Currently 34 of the original station points are identified and included in the in the UNESCO World Heritage list. identified original measurement points of the Meridian Arc are located in Sweden (7 points), Norway (15), Finland (83), Russia (1), Estonia (22), Latvia (16), Lithuania (18), Belorussia (28), Ukraine (59) and Moldova (27). In Year 2002 was initiated another large coverage project - European Position Determination System "EUPOS®". Currently there are about 400 continuously operating GNSS (Global Navigation Satellite Systems) stations covering EU countries Estonia, Latvia, Lithuania, Poland, Czech Republic, Slovakia, Hungary, Bulgaria, Romania and East European countries Ukraine and Moldavia. EUPOS® network is a ground based GNSS augmentation system widely used for geodesy, land surveying, geophysics and navigation. It gives the opportunity for fast and accurate position determination never available before. It is an honorable task to use the EUPOS® system for research of the Struve triangulation former sites. Projects with Struve arc can popularize geodesy, geo-information and its meaning in nowadays GIS and GNSS systems. Struve Arc and its points is unique cooperation cross-border object which deserve special attention because of their natural beauty and historical value for mankind. GNSS in geodesy discovers a powerful tool for the verification and validation of the height values of geodetic leveling benchmarks established historically almost 200 years ago. The differential GNSS and RTK methods appear very useful to identify vertical displacement of landscape by means of

Engineering uses of physics-based ground motion simulations

Science.gov (United States)

Baker, Jack W.; Luco, Nicolas; Abrahamson, Norman A.; Graves, Robert W.; Maechling, Phillip J.; Olsen, Kim B.

2014-01-01

This paper summarizes validation methodologies focused on enabling ground motion simulations to be used with confidence in engineering applications such as seismic hazard analysis and dynmaic analysis of structural and geotechnical systems. Numberical simullation of ground motion from large erthquakes, utilizing physics-based models of earthquake rupture and wave propagation, is an area of active research in the earth science community. Refinement and validatoin of these models require collaboration between earthquake scientists and engineering users, and testing/rating methodolgies for simulated ground motions to be used with confidence in engineering applications. This paper provides an introduction to this field and an overview of current research activities being coordinated by the Souther California Earthquake Center (SCEC). These activities are related both to advancing the science and computational infrastructure needed to produce ground motion simulations, as well as to engineering validation procedures. Current research areas and anticipated future achievements are also discussed.

Principle and Design of a Single-phase Inverter-Based Grounding System for Neutral-to-ground Voltage Compensation in Distribution Networks

DEFF Research Database (Denmark)

Wang, Wen; Yan, Lingjie; Zeng, Xiangjun

2017-01-01

Neutral-to-ground overvoltage may occur in non-effectively grounded power systems because of the distributed parameters asymmetry and resonance between Petersen coil and distributed capacitances. Thus, the constraint of neutral-to-ground voltage is critical for the safety of distribution networks....... In this paper, an active grounding system based on single-phase inverter and its control parameter design method is proposed to achieve this objective. Relationship between its output current and neutral-to-ground voltage is derived to explain the principle of neutral-to-ground voltage compensation. Then...

Atmospheric mercury concentrations observed at ground-based monitoring sites globally distributed in the framework of the GMOS network

Directory of Open Access Journals (Sweden)

F. Sprovieri

2016-09-01

Full Text Available Long-term monitoring of data of ambient mercury (Hg on a global scale to assess its emission, transport, atmospheric chemistry, and deposition processes is vital to understanding the impact of Hg pollution on the environment. The Global Mercury Observation System (GMOS project was funded by the European Commission (http://www.gmos.eu and started in November 2010 with the overall goal to develop a coordinated global observing system to monitor Hg on a global scale, including a large network of ground-based monitoring stations, ad hoc periodic oceanographic cruises and measurement flights in the lower and upper troposphere as well as in the lower stratosphere. To date, more than 40 ground-based monitoring sites constitute the global network covering many regions where little to no observational data were available before GMOS. This work presents atmospheric Hg concentrations recorded worldwide in the framework of the GMOS project (2010–2015, analyzing Hg measurement results in terms of temporal trends, seasonality and comparability within the network. Major findings highlighted in this paper include a clear gradient of Hg concentrations between the Northern and Southern hemispheres, confirming that the gradient observed is mostly driven by local and regional sources, which can be anthropogenic, natural or a combination of both.

Additional examination on station blackout caused by tsunami in Fukushima Daiichi NPS

International Nuclear Information System (INIS)

Yamauchi, Daisuke; Date, Kenji; Mizokami, Masato; Honda, Takeshi; Nozaki, Kenichiro; Mizokami, Shinya; Endo, Ryohei

2017-01-01

This study is additional examination to verify in a more reliable way the assessment that the emergency AC power supply was lost due to tsunami at Fukushima Daiichi Nuclear Power Station. It confirmed the relationship between the path length of tsunami intrusion reaching each power supply facility and the function loss time. As a result of examination, it was confirmed that as the path length of the tsunami intrusion reaching each power supply facility was longer, the function loss time tended to be later. So, conventional assessment that the function of each power supply facility was lost due to the run-up and flooding of tsunami has become more probable. For facilities, where the overall trend and the loss time of function were divergent, it was found that there were scenarios that could reasonably be explained. Based on the fact that the Fukushima Daiichi Nuclear Power Station lost power due to the tsunami, Kashiwazaki-Kariwa Nuclear Power Station carries out various safety measures. First of all, as the measures to prevent accidents caused by tsunami, the following have been applied: (1) prevention of the inflow of tsunamis into premises, (2) water prevention of the areas installed with important equipment, (3) securement of seawater at the time of backwashing, (4) storage of portable equipment at high ground, (5) installation of tsunami surveillance cameras. To prepare for the loss of power supply, this station implemented power supply facilities such as generator cars and distribution boards, as well as the placement of power supply cars at high ground. (A.O.)

Ground-Based Global Positioning System (GPS) Meteorology Integrated Precipitable Water Vapor (IPW)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Ground-Based Global Positioning System (GPS) Meteorology Integrated Precipitable Water Vapor (IPW) data set measures atmospheric water vapor using ground-based...

Developmental state and perspectives of USSR power stations, espec. nuclear power stations

International Nuclear Information System (INIS)

1983-01-01

According to the resolutions of the 25th and 26th party congresses of the CPSU, the Soviet electric and thermal energy economy envisages as the mainstreams in development: Energy projects based on nuclear fuel, i.e. nuclear power stations (NPS), nuclear heat- and -power stations (NHPS) and nuclear heat stations (NHS); fuel-energy complexes: Ekibastuz, Kansk-Achinsk, West-Siberian complex (Tyumen); power stations utilizing non-conventional regenerative energy sources, i.e. solar, geothermal, MHD power stations. Further down, an overview is given on the developmental perspectives of nuclear-heat and nuclear-power economy and on the development of energy management based on fossil fuels. (orig./UA) [de

Assesment of Carbon Credits for Power Generation Systems at GSM Base Station Site

OpenAIRE

Ani, Vincent Anayochukwu; Ani, Emmanuel Onyeka

2016-01-01

Electricity production is often a source of CO2 emissions, for instance when fossil fuel is combusted in power plants. Therefore the root cause of pollution coming from telecommunication industry is the source of energy (diesel genset) the network operators used in running their Base station sites. Energy consumption of using diesel to power base station by telecom networks is a contributor to global greenhouse gas (GHG) emissions. This paper presents the comparative carbon credits of hybrid ...

Strong ground motion of the 2016 Kumamoto earthquake

Science.gov (United States)

Aoi, S.; Kunugi, T.; Suzuki, W.; Kubo, H.; Morikawa, N.; Fujiwara, H.

2016-12-01

The 2016 Kumamoto earthquake that is composed of Mw 6.1 and Mw 7.1 earthquakes respectively occurred in the Kumamoto region at 21:26 on April 14 and 28 hours later at 1:25 on April 16, 2016 (JST). These earthquakes are considered to rupture mainly the Hinagu fault zone for the Mw 6.1 event and the Futagawa fault zone for the Mw 7.1 event, respectively, where the Headquarter for Earthquake Research Promotion performed the long-term evaluation as well as seismic hazard assessment prior to the 2016 Kumamoto earthquake. Strong shakings with seismic intensity 7 in the JMA scale were observed at four times in total: Mashiki town for the Mw 6.1 and Mw 7.1 events, Nishihara village for the Mw 7.1 event, and NIED/KiK-net Mashiki (KMMH16) for the Mw 7.1 event. KiK-net Mashiki (KMMH16) recorded peak ground acceleration more than 1000 cm/s/s, and Nishihara village recorded peak ground velocity more than 250 cm/s. Ground motions were observed wider area for the Mw 7.1 event than the Mw 6.1 event. Peak ground accelerations and peak ground velocities of K-NET/KiK-net stations are consistent with the ground motion prediction equations by Si and Midorikawa (1999). Peak ground velocities at longer distance than 200 km attenuate slowly, which can be attributed to the large Love wave with a dominant period around 10 seconds. 5%-damped pseudo spectral velocity of the Mashiki town shows a peak at period of 1-2 s that exceeds ground motion response of JR Takatori of the 1995 Kobe earthquake and the Kawaguchi town of the 2004 Chuetsu earthquake. 5%-damped pseudo spectral velocity of the Nishihara village shows 350 cm/s peak at period of 3-4 s that is similar to the several stations in Kathmandu basin by Takai et al. (2016) during the 2015 Gorkha earthquake in Nepal. Ground motions at several stations in Oita exceed the ground motion prediction equations due to an earthquake induced by the Mw 7.1 event. Peak ground accelerations of K-NET Yufuin (OIT009) records 90 cm/s/s for the Mw 7

A Full Cost Analysis of the Replacement of Naval Base, Guantanamo Bay's Marine Ground Defense Force by the Fleet Antiterrorism Security Team

National Research Council Canada - National Science Library

Ordona, Placido

2000-01-01

... of these diminishing resources. One such initiative is the restructuring of the Marine security presence at Naval Station, Guantanamo Bay, Cuba, through the replacement of the 350 man Marine Ground Defense Force with a smaller...

Ground-Laboratory to In-Space Atomic Oxygen Correlation for the PEACE Polymers

Science.gov (United States)

Stambler, Arielle H.; Inoshita, Karen E.; Roberts, Lily M.; Barbagallo, Claire E.; de Groh, Kim K.; Banks, Bruce A.

2009-01-01

The Materials International Space Station Experiment 2 (MISSE 2) Polymer Erosion and Contamination Experiment (PEACE) polymers were exposed to the environment of low Earth orbit (LEO) for 3.95 years from 2001 to 2005. There were forty-one different PEACE polymers, which were flown on the exterior of the International Space Station (ISS) in order to determine their atomic oxygen erosion yields. In LEO, atomic oxygen is an environmental durability threat, particularly for long duration mission exposures. Although space flight experiments, such as the MISSE 2 PEACE experiment, are ideal for determining LEO environmental durability of spacecraft materials, ground-laboratory testing is often relied upon for durability evaluation and prediction. Unfortunately, significant differences exist between LEO atomic oxygen exposure and atomic oxygen exposure in ground-laboratory facilities. These differences include variations in species, energies, thermal exposures and radiation exposures, all of which may result in different reactions and erosion rates. In an effort to improve the accuracy of ground-based durability testing, ground-laboratory to in-space atomic oxygen correlation experiments have been conducted. In these tests, the atomic oxygen erosion yields of the PEACE polymers were determined relative to Kapton H using a radio-frequency (RF) plasma asher (operated on air). The asher erosion yields were compared to the MISSE 2 PEACE erosion yields to determine the correlation between erosion rates in the two environments. This paper provides a summary of the MISSE 2 PEACE experiment; it reviews the specific polymers tested as well as the techniques used to determine erosion yield in the asher, and it provides a correlation between the space and ground-laboratory erosion yield values. Using the PEACE polymers' asher to in-space erosion yield ratios will allow more accurate in-space materials performance predictions to be made based on plasma asher durability evaluation.

The Mediterranean Oscillation Teleconnection Index: Station-Based versus Principal Component Paradigms

Directory of Open Access Journals (Sweden)

Francisco Criado-Aldeanueva

2013-01-01

Full Text Available Two different paradigms of the Mediterranean Oscillation (MO teleconnection index have been compared in this work: station-based definitions obtained by the difference of some climate variable between two selected points in the eastern and western basins (i.e., Algiers and Cairo, Gibraltar and Israel, Marseille and Jerusalem, or south France and Levantine basin and the principal component (PC approach in which the index is obtained as the time series of the first mode of normalised sea level pressure anomalies across the extended Mediterranean region. Interannual to interdecadal precipitation (P, evaporation (E, E-P, and net heat flux have been correlated with the different MO indices to compare their relative importance in the long-term variability of heat and freshwater budgets over the Mediterranean Sea. On an annual basis, the PC paradigm is the most effective tool to assess the effect of the large-scale atmospheric forcing in the Mediterranean Sea because the station-based indices exhibit a very poor correlation with all climatic variables and only influence a reduced fraction of the basin. In winter, the station-based indices highly improve their ability to represent the atmospheric forcing and results are fairly independent of the paradigm used.

Automation for a base station stability testing

OpenAIRE

Punnek, Elvis

2016-01-01

This Batchelor’s thesis was commissioned by Oy LM Ericsson Ab Oulu. The aim of it was to help to investigate and create a test automation solution for the stability testing of the LTE base station. The main objective was to create a test automation for a predefined test set. This test automation solution had to be created for specific environments and equipment. This work included creating the automation for the test cases and putting them to daily test automation jobs. The key factor...

Neural network based inspection of voids and karst conduits in hydro-electric power station tunnels using GPR

Science.gov (United States)

Kilic, Gokhan; Eren, Levent

2018-04-01

This paper reports on the fundamental role played by Ground Penetrating Radar (GPR), alongside advanced processing and presentation methods, during the tunnel boring project at a Dam and Hydro-Electric Power Station. It identifies from collected GPR data such issues as incomplete grouting and the presence of karst conduits and voids and provides full details of the procedures adopted. In particular, the application of collected GPR data to the Neural Network (NN) method is discussed.

Objective structured clinical examination "Death Certificate" station - Computer-based versus conventional exam format.

Science.gov (United States)

Biolik, A; Heide, S; Lessig, R; Hachmann, V; Stoevesandt, D; Kellner, J; Jäschke, C; Watzke, S

2018-04-01

One option for improving the quality of medical post mortem examinations is through intensified training of medical students, especially in countries where such a requirement exists regardless of the area of specialisation. For this reason, new teaching and learning methods on this topic have recently been introduced. These new approaches include e-learning modules or SkillsLab stations; one way to objectify the resultant learning outcomes is by means of the OSCE process. However, despite offering several advantages, this examination format also requires considerable resources, in particular in regards to medical examiners. For this reason, many clinical disciplines have already implemented computer-based OSCE examination formats. This study investigates whether the conventional exam format for the OSCE forensic "Death Certificate" station could be replaced with a computer-based approach in future. For this study, 123 students completed the OSCE "Death Certificate" station, using both a computer-based and conventional format, half starting with the Computer the other starting with the conventional approach in their OSCE rotation. Assignment of examination cases was random. The examination results for the two stations were compared and both overall results and the individual items of the exam checklist were analysed by means of inferential statistics. Following statistical analysis of examination cases of varying difficulty levels and correction of the repeated measures effect, the results of both examination formats appear to be comparable. Thus, in the descriptive item analysis, while there were some significant differences between the computer-based and conventional OSCE stations, these differences were not reflected in the overall results after a correction factor was applied (e.g. point deductions for assistance from the medical examiner was possible only at the conventional station). Thus, we demonstrate that the computer-based OSCE "Death Certificate" station

Assessment of natural attenuation of ground-water contamination at sites FT03, LF13, and WP14/LF15, Dover Air Force Base, Delaware

Science.gov (United States)

Barbaro, Jeffrey R.

2002-01-01

Water-quality, aquifer-sediment, and hydro-logic data were used to assess the effectiveness of natural attenuation of ground-water contamination at Fire Training Area Three, the Rubble Area Landfill, the Liquid Waste Disposal Landfill, and the Receiver Station Landfill in the East Management Unit of Dover Air Force Base, Delaware. These sites, which are contaminated with chlorinated solvents and fuel hydrocarbons, are under-going long-term monitoring to determine if natural attenuation continues to sufficiently reduce contaminant concentrations to meet regulatory requirements. This report is the first assessment of the effectiveness of natural attenuation at these sites since long-term monitoring began in 1999, and follows a preliminary investigation done in 1995?96. This assessment was done by the U.S. Geological Survey in cooperation with the U.S. Air Force.Since 1995?96, additional information has been collected and used in the current assessment. The conclusions in this report are based primarily on ground-water samples collected from January through March 2000. Previous analytical results from selected wells, available geologic and geo-physical well logs, and newly acquired information such as sediment organic-carbon measurements, hydraulic-conductivity measurements determined from slug tests on wells in the natural attenuation study area, and water-level measurements from surficial-aquifer wells also were used in this assessment. This information was used to: (1) calculate retardation factors and estimate contaminant migration velocities, (2) improve estimates of ground-water flow directions and inferred contaminant migration pathways, (3) better define the areal extent of contamination and the proximity of contaminants to discharge areas and the Base boundary, (4) develop a better under-standing of the vertical variability of contaminant concentrations and redox conditions, (5) evaluate the effects of temporal changes on concentrations in the plumes and

Predictors of suicide and suicide attempt in subway stations: a population-based ecological study.

Science.gov (United States)

Niederkrotenthaler, Thomas; Sonneck, Gernot; Dervic, Kanita; Nader, Ingo W; Voracek, Martin; Kapusta, Nestor D; Etzersdorfer, Elmar; Mittendorfer-Rutz, Ellenor; Dorner, Thomas

2012-04-01

Suicidal behavior on the subway often involves young people and has a considerable impact on public life, but little is known about factors associated with suicides and suicide attempts in specific subway stations. Between 1979 and 2009, 185 suicides and 107 suicide attempts occurred on the subway in Vienna, Austria. Station-specific suicide and suicide attempt rates (defined as the frequency of suicidal incidents per time period) were modeled as the outcome variables in bivariate and multivariate Poisson regression models. Structural station characteristics (presence of a surveillance unit, train types used, and construction on street level versus other construction), contextual station characteristics (neighborhood to historical sites, size of the catchment area, and in operation during time period of extensive media reporting on subway suicides), and passenger-based characteristics (number of passengers getting on the trains per day, use as meeting point by drug users, and socioeconomic status of the population in the catchment area) were used as the explanatory variables. In the multivariate analyses, subway suicides increased when stations were served by the faster train type. Subway suicide attempts increased with the daily number of passengers getting on the trains and with the stations' use as meeting points by drug users. The findings indicate that there are some differences between subway suicides and suicide attempts. Completed suicides seem to vary most with train type used. Suicide attempts seem to depend mostly on passenger-based characteristics, specifically on the station's crowdedness and on its use as meeting point by drug users. Suicide-preventive interventions should concentrate on crowded stations and on stations frequented by risk groups.

Simulation of Ground-Water Flow and Effects of Ground-Water Irrigation on Base Flow in the Elkhorn and Loup River Basins, Nebraska

Science.gov (United States)

Peterson, Steven M.; Stanton, Jennifer S.; Saunders, Amanda T.; Bradley, Jesse R.

2008-01-01

Irrigated agriculture is vital to the livelihood of communities in the Elkhorn and Loup River Basins in Nebraska, and ground water is used to irrigate most of the cropland. Concerns about the sustainability of ground-water and surface-water resources have prompted State and regional agencies to evaluate the cumulative effects of ground-water irrigation in this area. To facilitate understanding of the effects of ground-water irrigation, a numerical computer model was developed to simulate ground-water flow and assess the effects of ground-water irrigation (including ground-water withdrawals, hereinafter referred to as pumpage, and enhanced recharge) on stream base flow. The study area covers approximately 30,800 square miles, and includes the Elkhorn River Basin upstream from Norfolk, Nebraska, and the Loup River Basin upstream from Columbus, Nebraska. The water-table aquifer consists of Quaternary-age sands and gravels and Tertiary-age silts, sands, and gravels. The simulation was constructed using one layer with 2-mile by 2-mile cell size. Simulations were constructed to represent the ground-water system before 1940 and from 1940 through 2005, and to simulate hypothetical conditions from 2006 through 2045 or 2055. The first simulation represents steady-state conditions of the system before anthropogenic effects, and then simulates the effects of early surface-water development activities and recharge of water leaking from canals during 1895 to 1940. The first simulation ends at 1940 because before that time, very little pumpage for irrigation occurred, but after that time it became increasingly commonplace. The pre-1940 simulation was calibrated against measured water levels and estimated long-term base flow, and the 1940 through 2005 simulation was calibrated against measured water-level changes and estimated long-term base flow. The calibrated 1940 through 2005 simulation was used as the basis for analyzing hypothetical scenarios to evaluate the effects of

Space Station Initial Operational Concept (IOC) operations and safety view - Automation and robotics for Space Station

Science.gov (United States)

Bates, William V., Jr.

1989-01-01

The automation and robotics requirements for the Space Station Initial Operational Concept (IOC) are discussed. The amount of tasks to be performed by an eight-person crew, the need for an automated or directed fault analysis capability, and ground support requirements are considered. Issues important in determining the role of automation for the IOC are listed.

The automated ground network system

Science.gov (United States)

Smith, Miles T.; Militch, Peter N.

1993-01-01

The primary goal of the Automated Ground Network System (AGNS) project is to reduce Ground Network (GN) station life-cycle costs. To accomplish this goal, the AGNS project will employ an object-oriented approach to develop a new infrastructure that will permit continuous application of new technologies and methodologies to the Ground Network's class of problems. The AGNS project is a Total Quality (TQ) project. Through use of an open collaborative development environment, developers and users will have equal input into the end-to-end design and development process. This will permit direct user input and feedback and will enable rapid prototyping for requirements clarification. This paper describes the AGNS objectives, operations concept, and proposed design.

Novel Base Station MIMO Antennas with Enhanced Spectral Efficiencies Using Angular Reuse

Directory of Open Access Journals (Sweden)

Miguel Mora-Andreu

2015-01-01

Full Text Available The true polarization diversity (TPD technique is combined with the spatial diversity technique in novel MIMO antenna array geometries with a large number of elements. The use of a large number of elements requires some angular reuse within the array for polarization diversity. With designs compatible with existing base station antenna array configurations, the novel geometries with combining diversity schemes are shown to be able to achieve near the maximum spectral efficiencies. True polarization diversity (TPD schemes are found to be an excellent complement to more conventional spatial diversity schemes for obtaining optimum MIMO array performance in base station antennas.

Ground Contact Analysis for Korea’s Fictitious Lunar Orbiter Mission

Directory of Open Access Journals (Sweden)

Young-Joo Song

2013-12-01

Full Text Available In this research, the ground contact opportunity for the fictitious low lunar orbiter is analyzed to prepare for a future Korean lunar orbiter mission. The ground contact opportunity is basically derived from geometrical relations between the typical ground stations at the Earth, the relative positions of the Earth and Moon, and finally, the lunar orbiter itself. Both the cut-off angle and the orbiter’s Line of Sight (LOS conditions (weather orbiter is located at near or far side of the Moon seen from the Earth are considered to determine the ground contact opportunities. Four KOMPSAT Ground Stations (KGSs are assumed to be Korea’s future Near Earth Networks (NENs to support lunar missions, and world-wide separated Deep Space Networks (DSNs are also included during the contact availability analysis. As a result, it is concluded that about 138 times of contact will be made between the orbiter and the Daejeon station during 27.3 days of prediction time span. If these contact times are converted into contact duration, the duration is found to be about 8.55 days, about 31.31% of 27.3 days. It is discovered that selected four KGSs cannot provide continuous tracking of the lunar orbiter, meaning that international collaboration is necessary to track Korea’s future lunar orbiter effectively. Possible combinations of world-wide separated DSNs are also suggested to compensate for the lack of contact availability with only four KGSs, as with primary and backup station concepts. The provided algorithm can be easily modified to support any type of orbit around the Moon, and therefore, the presented results could aid further progress in the design field of Korea’s lunar orbiter missions.

Enhanced science capability on the International Space Station

Science.gov (United States)

Felice, Ronald R.; Kienlen, Mike

2002-12-01

, providing, in part, science solid state recorders and instrument command management sub-systems. This, together with just one direct-to-ground based X-Band station co-located with a science payload operations center provides for a direct data path to ground, bypassing NASA institutions. The science center exists to receive user service requests, perform required constraint checks necessary for safe instrument operations, and to disseminate user science data. Payload commands can be up-linked directly or, if required, relayed through the existing NASA institution. The concept is modular for the downlink Earth terminals; in that multiple downlink X-band ground stations can be utilized throughout the world. This has applications for Earth science data direct to regional centers similar to those services provided by the EOS Terra spacecraft. However, for the purposes of this concept, just one downlink site was selected in order to define the worst-case data acquisition scenario necessary to ascertain concept feasibility. The paper demonstrates that the concept is feasible and can lead to a design that significantly reduces operational dependency on the NASA institutions and astronauts while significantly increasing ISS science operational efficiency and access.

Mobile phone base stations and adverse health effects: phase 1 of a population-based, cross-sectional study in Germany

DEFF Research Database (Denmark)

Blettner, M; Schlehofer, B; Breckenkamp, J

2009-01-01

OBJECTIVE: The aim of this first phase of a cross-sectional study from Germany was to investigate whether proximity of residence to mobile phone base stations as well as risk perception is associated with health complaints. METHODS: The researchers conducted a population-based, multi-phase, cross......-sectional study within the context of a large panel survey regularly carried out by a private research institute in Germany. In the initial phase, reported on in this paper, 30,047 persons from a total of 51,444 who took part in the nationwide survey also answered questions on how mobile phone base stations...... affected their health. A list of 38 health complaints was used. A multiple linear regression model was used to identify predictors of health complaints including proximity of residence to mobile phone base stations and risk perception. RESULTS: Of the 30,047 participants (response rate 58.6%), 18...

East–West GEO Satellite Station-Keeping with Degraded Thruster Response

Directory of Open Access Journals (Sweden)

Stoian Borissov

2015-09-01

Full Text Available The higher harmonic terms of Earth’s gravitational potential slowly modify the nominal longitude of geostationary Earth orbit (GEO satellites, while the third-body presence (Moon and Sun mainly affects their latitude. For this reason, GEO satellites periodically need to perform station-keeping maneuvers, namely, east–west and north–south maneuvers to compensate for longitudinal and latitudinal variations, respectively. During the operational lifetime of GEO satellites, the thrusters’ response when commanded to perform these maneuvers slowly departs from the original nominal impulsive behavior. This paper addresses the practical problem of how to perform reliable east–west station-keeping maneuvers when thruster response is degraded. The need for contingency intervention from ground-based satellite operators is reduced by breaking apart the scheduled automatic station-keeping maneuvers into smaller maneuvers. Orbital alignment and attitude are tracked on-board during and in between sub-maneuvers, and any off nominal variations are corrected for with subsequent maneuvers. These corrections are particularly important near the end of the lifetime of GEO satellites, where thruster response is farthest from nominal performance.

Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

International Nuclear Information System (INIS)

Casey, Leslie A.

2014-01-01

This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

Energy Technology Data Exchange (ETDEWEB)

Casey, Leslie A.

2014-01-13

This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

The COROT ground-based archive and access system

Science.gov (United States)

Solano, E.; González-Riestra, R.; Catala, C.; Baglin, A.

2002-01-01

A prototype of the COROT ground-based archive and access system is presented here. The system has been developed at LAEFF and it is based on the experience gained at Laboratorio de Astrofisica Espacial y Fisica Fundamental (LAEFF) with the INES (IUE Newly Extracted System) Archive.

A detrimental soil disturbance prediction model for ground-based timber harvesting

Science.gov (United States)

Derrick A. Reeves; Matthew C. Reeves; Ann M. Abbott; Deborah S. Page-Dumroese; Mark D. Coleman

2012-01-01

Soil properties and forest productivity can be affected during ground-based harvest operations and site preparation. The degree of impact varies widely depending on topographic features and soil properties. Forest managers who understand site-specific limits to ground-based harvesting can alter harvest method or season to limit soil disturbance. To determine the...

Effects of mid-latitude ionosphere observed from ground-based ionosonde data obtained at Alma-Ata station during strong geomagnetic storms

International Nuclear Information System (INIS)

Gordienko, G.I.; Vodynnikov, V.V.; Yakovets, A.E.

2006-01-01

The ionospheric effects of fourteen great geomagnetic storms occurred in the 1986-2005 time period observed over Alma-Ata (43.25 N , 76.92 E ) were studied experimentally using ground-based ionosonde. The observations showed a number of unusual (for the Alma-Ata location) ionospheric phenomena during the active phase of geomagnetic storms, along with a negative phase in the ionospheric F2-layer disturbance an anomalous formation of the E, E2, and F1 layers at nighttime, and the appearance of aurora-type sporadic E layers were found. Processes of interaction of energetic neutrals with the upper atmosphere modeled by Bauske et al. (1997) for magnetically distributed condition seem to explain the phenomena of ionization of F1 and E region at night. (author)

Space station operations task force. Panel 4 report: Management integration

Science.gov (United States)

1987-01-01

The Management Integration Panel of the Space Station Operations Task Force was chartered to provide a structure and ground rules for integrating the efforts of the other three panels and to address a number of cross cutting issues that affect all areas of space station operations. Issues addressed include operations concept implementation, alternatives development and integration process, strategic policy issues and options, and program management emphasis areas.

Ozone ground-based measurements by the GASCOD near-UV and visible DOAS system

Science.gov (United States)

Giovanelli, G.; Bonasoni, P.; Cervino, M.; Evangelisti, F.; Ravegnani, F.

1994-01-01

GASCOD, a near-ultraviolet and visible differential optical spectrometer, was developed at CNR's FISBAT Institute in Bologna, Italy, and first tested at Terra Nova Bay station in Antarctica (74.6 deg S, 164.6 deg E) during the summer expeditions 1988-1990 of PNRA (PNRA is the national research program in Antarctica, 'Programma Nazionale di Ricerche in Atartide'). A comparison with coincident O3 total column measurements taken in the same Antarctic area is presented, as is another comparison performed in Italy. Also introduced is an updated model for solar zenith measurements taken from a ground-based, upward-looking GASCOD spectrometer, which was employed for the 1991-92 winter campaign at Aer-Ostersund in Sweden (63.3 deg N, 13.1 deg E) during AESOE (European Arctic Stratospheric Ozone Experiment). The GASCOD can examine the spectra from 300 to 700 nm, in 50 nm steps, by moving the spectrometer's grating. At present, it takes measurements of solar zenith radiation in the 310-342 nm range for O3 and in the 405-463 nm range for NO2.

Analyzing mobile WiMAX base station deployment under different frequency planning strategies

Science.gov (United States)

Salman, M. K.; Ahmad, R. B.; Ali, Ziad G.; Aldhaibani, Jaafar A.; Fayadh, Rashid A.

2015-05-01

The frequency spectrum is a precious resource and scarce in the communication markets. Therefore, different techniques are adopted to utilize the available spectrum in deploying WiMAX base stations (BS) in cellular networks. In this paper several types of frequency planning techniques are illustrated, and a comprehensive comparative study between conventional frequency reuse of 1 (FR of 1) and fractional frequency reuse (FFR) is presented. These techniques are widely used in network deployment, because they employ universal frequency (using all the available bandwidth) in their base station installation/configuration within network system. This paper presents a network model of 19 base stations in order to be employed in the comparison of the aforesaid frequency planning techniques. Users are randomly distributed within base stations, users' resource mapping and their burst profile selection are based on the measured signal to interference plus-noise ratio (SINR). Simulation results reveal that the FFR has advantages over the conventional FR of 1 in various metrics. 98 % of downlink resources (slots) are exploited when FFR is applied, whilst it is 81 % at FR of 1. Data rate of FFR has been increased to 10.6 Mbps, while it is 7.98 Mbps at FR of 1. The spectral efficiency is better enhanced (1.072 bps/Hz) at FR of 1 than FFR (0.808 bps/Hz), since FR of 1 exploits all the Bandwidth. The subcarrier efficiency shows how many data bits that can be carried by subcarriers under different frequency planning techniques, the system can carry more data bits under FFR (2.40 bit/subcarrier) than FR of 1 (1.998 bit/subcarrier). This study confirms that FFR can perform better than conventional frequency planning (FR of 1) which made it a strong candidate for WiMAX BS deployment in cellular networks.

Study on dynamic behavior of large-scale foundation on soft ground, (6)

International Nuclear Information System (INIS)

Sawada, Yoshihiro; Yajima, Hiroshi; Esashi, Yasuyuki; Sakurai, Akio

1983-01-01

Generally, the earthquake motion in the basements of buildings and foundations shows smaller amplitude than that on ground surface. As the cause, there are two interpretations, the interaction of ground and structures and the input loss of earthquake motion due to the restriction by foundations. It is important to urgently clarify this problem in case of the aseismatic design of nuclear power stations at the location of Quaternary ground. For the purpose, the observation of earthquakes was performed with simple flat foundations and in the surrounding ground, in which the effect of locking and upper structures was negligible. The obtained data were compared with the theoretical solutions according to the above two interpretations, thus it was attempted to clarify the mechanism of restricting earthquake motion by foundations. The foundations were a foundation of 30 cm diameter and 2 cm thickness made by improving the superweak ground with nearly zero N-value by cement mixing treatment and a large concrete base of 90 x 45 x 21 m constructed in sandy gravellayer. The mecahnism of restricting vibration was due to the reflection effect of input energy at the boundary between rigid bases and the soft ground right under them, and it can be estimated by multiple reflection theory. (Kako, I.)

Applicability of an exposure model for the determination of emissions from mobile phone base stations

DEFF Research Database (Denmark)

Breckenkamp, J; Neitzke, H P; Bornkessel, C

2008-01-01

Applicability of a model to estimate radiofrequency electromagnetic field (RF-EMF) strength in households from mobile phone base stations was evaluated with technical data of mobile phone base stations available from the German Net Agency, and dosimetric measurements, performed in an epidemiologi......Applicability of a model to estimate radiofrequency electromagnetic field (RF-EMF) strength in households from mobile phone base stations was evaluated with technical data of mobile phone base stations available from the German Net Agency, and dosimetric measurements, performed...... in an epidemiological study. Estimated exposure and exposure measured with dosemeters in 1322 participating households were compared. For that purpose, the upper 10th percentiles of both outcomes were defined as the 'higher exposed' groups. To assess the agreement of the defined 'higher' exposed groups, kappa...... coefficient, sensitivity and specificity were calculated. The present results show only a weak agreement of calculations and measurements (kappa values between -0.03 and 0.28, sensitivity between 7.1 and 34.6). Only in some of the sub-analyses, a higher agreement was found, e.g. when measured instead...

Space Station technology testbed: 2010 deep space transport

Science.gov (United States)

Holt, Alan C.

1993-01-01

A space station in a crew-tended or permanently crewed configuration will provide major R&D opportunities for innovative, technology and materials development and advanced space systems testing. A space station should be designed with the basic infrastructure elements required to grow into a major systems technology testbed. This space-based technology testbed can and should be used to support the development of technologies required to expand our utilization of near-Earth space, the Moon and the Earth-to-Jupiter region of the Solar System. Space station support of advanced technology and materials development will result in new techniques for high priority scientific research and the knowledge and R&D base needed for the development of major, new commercial product thrusts. To illustrate the technology testbed potential of a space station and to point the way to a bold, innovative approach to advanced space systems' development, a hypothetical deep space transport development and test plan is described. Key deep space transport R&D activities are described would lead to the readiness certification of an advanced, reusable interplanetary transport capable of supporting eight crewmembers or more. With the support of a focused and highly motivated, multi-agency ground R&D program, a deep space transport of this type could be assembled and tested by 2010. Key R&D activities on a space station would include: (1) experimental research investigating the microgravity assisted, restructuring of micro-engineered, materials (to develop and verify the in-space and in-situ 'tuning' of materials for use in debris and radiation shielding and other protective systems), (2) exposure of microengineered materials to the space environment for passive and operational performance tests (to develop in-situ maintenance and repair techniques and to support the development, enhancement, and implementation of protective systems, data and bio-processing systems, and virtual reality and

SISTEM PAKAR TROUBLESHOOTING BASE TRANSCEIVER STATION UNTUK EFISIENSI KINERJA TEKNISI (STUDI KASUS : PT.KMS TELECOM PEKANBARU

Directory of Open Access Journals (Sweden)

Yogi Yunefri

2016-02-01

Full Text Available AbstrakBase Transceiver Station (BTS terdiri dari modul-modul yang memiliki indikator alarm untuk mengindikasikan adanya error pada komponen dalam sistemnya. Kurangnya tenaga ahli alarm BTS, menyebabkan para operator harus terlebih dahulu membuka buletin atau referensi lainnya untuk mengetahui penanganan dari tiap alarm sehingga tidak terjadi kesalahan fatal. Keterbatasan itulah yang menyebabkan PT.KMS Pekanbaru cukup kesulitan untuk melakukan troubleshooting dengan cepat.Kata Kunci : Base Transceiver Station, expert systems, TelecomunicationAbstractBase Transceiver Station ( BTS consists From the module - The module has an alarm indicator to indicate an error review their hearts IN Component system. Lack Expert BTS alarm , the operator causes the first Must Opens bulletin Other references to review the handling From each alarm know that NOT fatal error occurred.The limitations that cause PT.KMS Pekanbaru Quite difficult to review conduct tips Quick WITH .Keywords: Base Transceiver Station, expert systems, Telecomunication

Ground-Based Telescope Parametric Cost Model

Science.gov (United States)

Stahl, H. Philip; Rowell, Ginger Holmes

2004-01-01

A parametric cost model for ground-based telescopes is developed using multi-variable statistical analysis, The model includes both engineering and performance parameters. While diameter continues to be the dominant cost driver, other significant factors include primary mirror radius of curvature and diffraction limited wavelength. The model includes an explicit factor for primary mirror segmentation and/or duplication (i.e.. multi-telescope phased-array systems). Additionally, single variable models based on aperture diameter are derived. This analysis indicates that recent mirror technology advances have indeed reduced the historical telescope cost curve.

KSC ADVANCED GROUND BASED FIELD MILL V1

Data.gov (United States)

National Aeronautics and Space Administration — The Advanced Ground Based Field Mill (AGBFM) network consists of 34 (31 operational) field mills located at Kennedy Space Center (KSC), Florida. The field mills...

A numerical study on the allowed sulpher content in fuel used by the power stations in Kuwait

International Nuclear Information System (INIS)

Ramadan, A. A.; AlsSdairawi, M.; AlHajraf, S.

2006-01-01

In Kuwait, most of the power stations use fuel oil as the prime source of energy. The sulphur content (S%) of the fuel used as well as other factors have a direct impact on the ground level concentration of sulphur dioxide (SO 2 ) released by the power stations into the atmosphere. The SO 2 ground level concentration has to meet the standards set by Kuwait Environmental Public Authority (KEPA). In this communication we present numerical results obtained using the Inustrial Sources Complex Short Team (ISC-ST) numerical model. The model calculated the SO 2 concentration resulting from existing power stations assuming a) zero background SO 2 concentration and b) entire reliance on Heavy Fuel Oil (HFO). Different scenarios represented by different S and, i.e. 0.5, 0.75, 1, 1.5, 2, 3, and 4% were simulated. For all power stations, the annual SO 2 concentrations for fuels with low sulphur content do not pose any risk on urban populations. Bubyan Islan and Subiya are considred ideal locations for future power stations. The majority of the pollutants around Kuwait City results from emissions from Doha East and Doha West power stations. The results are expected to benefit Kuwait Petroleum Corporation in improving the quality of the fuel produced for consumption by the power stations in Kuwait in order to maintain an acceptable ground level of SO 2 .(Author)

PC-based control of the internal target station at the Nuclotron

Energy Technology Data Exchange (ETDEWEB)

Kilman, J [and others

1996-12-31

A PC-based control system of the internal target at the Nuclotron is described. The system is based on CAMAC-control of the step motor of the station and screen representation of information about needed beam parameters and space-time position of targets relative to a beam. 6 refs.; 4 figs.

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz.

Science.gov (United States)

Vermeeren, G; Gosselin, M C; Kühn, S; Kellerman, V; Hadjem, A; Gati, A; Joseph, W; Wiart, J; Meyer, F; Kuster, N; Martens, L

2010-09-21

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz

International Nuclear Information System (INIS)

Vermeeren, G; Joseph, W; Martens, L; Gosselin, M C; Kuehn, S; Kuster, N; Kellerman, V; Meyer, F; Hadjem, A; Gati, A; Wiart, J

2010-01-01

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz

Energy Technology Data Exchange (ETDEWEB)

Vermeeren, G; Joseph, W; Martens, L [Ghent University-INTEC/IBBT, Gaston Crommenlaan 8 box 201, B-9050 Ghent (Belgium); Gosselin, M C; Kuehn, S; Kuster, N [IT' IS Foundation, Zurich (Switzerland); Kellerman, V; Meyer, F [EMSS, Stellenbosch (South Africa); Hadjem, A; Gati, A; Wiart, J, E-mail: Gunter.Vermeeren@intec.UGent.b [Orange Labs, Paris (France)

2010-09-21

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

Biomass burning aerosols characterization from ground based and profiling measurements

Science.gov (United States)

Marin, Cristina; Vasilescu, Jeni; Marmureanu, Luminita; Ene, Dragos; Preda, Liliana; Mihailescu, Mona

2018-04-01

The study goal is to assess the chemical and optical properties of aerosols present in the lofted layers and at the ground. The biomass burning aerosols were evaluated in low level layers from multi-wavelength lidar measurements, while chemical composition at ground was assessed using an Aerosol Chemical Speciation Monitor (ACSM) and an Aethalometer. Classification of aerosol type and specific organic markers were used to explore the potential to sense the particles from the same origin at ground base and on profiles.

Ambient Noise Green's Function Simulation of Long-Period Ground Motions for Reverse Faulting

Science.gov (United States)

Miyake, H.; Beroza, G. C.

2009-12-01

Long-time correlation of ambient seismic noise has been demonstrated as a useful tool for strong ground motion prediction [Prieto and Beroza, 2008]. An important advantage of ambient noise Green's functions is that they can be used for ground motion simulation without resorting to either complex 3-D velocity structure to develop theoretical Green’s functions, or aftershock records for empirical Green’s function analysis. The station-to-station approach inherent to ambient noise Green’s functions imposes some limits to its application, since they are band-limited, applied at the surface, and for a single force. We explore the applicability of this method to strong motion prediction using the 2007 Chuetsu-oki, Japan, earthquake (Mw 6.6, depth = 9 km), which excited long-period ground motions in and around the Kanto basin almost 200 km from the epicenter. We test the performance of ambient noise Green's function for long-period ground motion simulation. We use three components of F-net broadband data at KZK station, which is located near the source region, as a virtual source, and three components of six F-net stations in and around the Kanto basin to calculate the response. An advantage to applying this approach in Japan is that ambient-noise sources are active in diverse directions. The dominant period of the ambient noise for the F-net datasets is mostly 7 s over the year, and amplitudes are largest in winter. This period matches the dominant periods of the Kanto and Niigata basins. For the 9 components of the ambient noise Green’s functions, we have confirmed long-period components corresponding to Love wave and Rayleigh waves that can be used for simulation of the 2007 Chuetsu-oki earthquake. The relative amplitudes, phases, and durations of the ambient noise Green’s functions at the F-net stations in and around the Kanto basin respect to F-net KZK station are fairly well matched with those of the observed ground motions for the 2007 Chuetsu

Control Method of Single-phase Inverter Based Grounding System in Distribution Networks

DEFF Research Database (Denmark)

Wang, Wen; Yan, L.; Zeng, X.

2016-01-01

of neutral-to-ground voltage is critical for the safety of distribution networks. An active grounding system based on single-phase inverter is proposed to achieve this objective. Relationship between output current of the system and neutral-to-ground voltage is derived to explain the principle of neutral......The asymmetry of the inherent distributed capacitances causes the rise of neutral-to-ground voltage in ungrounded system or high resistance grounded system. Overvoltage may occur in resonant grounded system if Petersen coil is resonant with the distributed capacitances. Thus, the restraint...

Radio frequency electromagnetic field compliance assessment of multi-band and MIMO equipped radio base stations.

Science.gov (United States)

Thors, Björn; Thielens, Arno; Fridén, Jonas; Colombi, Davide; Törnevik, Christer; Vermeeren, Günter; Martens, Luc; Joseph, Wout

2014-05-01

In this paper, different methods for practical numerical radio frequency exposure compliance assessments of radio base station products were investigated. Both multi-band base station antennas and antennas designed for multiple input multiple output (MIMO) transmission schemes were considered. For the multi-band case, various standardized assessment methods were evaluated in terms of resulting compliance distance with respect to the reference levels and basic restrictions of the International Commission on Non-Ionizing Radiation Protection. Both single frequency and multiple frequency (cumulative) compliance distances were determined using numerical simulations for a mobile communication base station antenna transmitting in four frequency bands between 800 and 2600 MHz. The assessments were conducted in terms of root-mean-squared electromagnetic fields, whole-body averaged specific absorption rate (SAR) and peak 10 g averaged SAR. In general, assessments based on peak field strengths were found to be less computationally intensive, but lead to larger compliance distances than spatial averaging of electromagnetic fields used in combination with localized SAR assessments. For adult exposure, the results indicated that even shorter compliance distances were obtained by using assessments based on localized and whole-body SAR. Numerical simulations, using base station products employing MIMO transmission schemes, were performed as well and were in agreement with reference measurements. The applicability of various field combination methods for correlated exposure was investigated, and best estimate methods were proposed. Our results showed that field combining methods generally considered as conservative could be used to efficiently assess compliance boundary dimensions of single- and dual-polarized multicolumn base station antennas with only minor increases in compliance distances. © 2014 Wiley Periodicals, Inc.

Environmental aspects of airbrone radioactive effluent from a coal-fired power station

International Nuclear Information System (INIS)

Song Miaofa; Fu Rongchu; Lu Zhizhao

1987-01-01

The authors determined the contents of natural uranium and thorium in coal and tunnel ash samples taken from a large coal-fired power station in the nearby area. The hourly climate data in 1980 are analysed and the atmospheric stability is cataloged by Pasquill-Turner method. Wind direction-atmospheric stability-wind velocity combined probabilities and rain-wind direction probabilities are calculated. The near ground air pollution concentrations, the ground depositions and the distributions of U and Th presented in airborne effluent (fly ash) within an area round the station with a radius of 60 km are also estimated. In the calculations, some factors such as wind velocity in the higher atmosphere, plume rise, still wind and decrease of air pollution concentration by the ground deposition (especially the wet deposition porduced by rain) have been considered. Some corrections necessary for the factors described above are also made. It is shown that the maximum annual average air pollution concentration (U max = 1.95 x 10 -7 mg.m -3 , Th max = 3.45 x 10 -7 mg.m -3 ) appears at the point 1 km away from the source in the fan SE. In the area round the station with a radius shorter than 10 km, the ground deposition is mainly by the wet deposition, but, where the radius longer than 10 km, the dry deposition must be taken into account

Modeling continuous seismic velocity changes due to ground shaking in Chile

Science.gov (United States)

Gassenmeier, Martina; Richter, Tom; Sens-Schönfelder, Christoph; Korn, Michael; Tilmann, Frederik

2015-04-01

In order to investigate temporal seismic velocity changes due to earthquake related processes and environmental forcing, we analyze 8 years of ambient seismic noise recorded by the Integrated Plate Boundary Observatory Chile (IPOC) network in northern Chile between 18° and 25° S. The Mw 7.7 Tocopilla earthquake in 2007 and the Mw 8.1 Iquique earthquake in 2014 as well as numerous smaller events occurred in this area. By autocorrelation of the ambient seismic noise field, approximations of the Green's functions are retrieved. The recovered function represents backscattered or multiply scattered energy from the immediate neighborhood of the station. To detect relative changes of the seismic velocities we apply the stretching method, which compares individual autocorrelation functions to stretched or compressed versions of a long term averaged reference autocorrelation function. We use time windows in the coda of the autocorrelations, that contain scattered waves which are highly sensitive to minute changes in the velocity. At station PATCX we observe seasonal changes in seismic velocity as well as temporary velocity reductions in the frequency range of 4-6 Hz. The seasonal changes can be attributed to thermal stress changes in the subsurface related to variations of the atmospheric temperature. This effect can be modeled well by a sine curve and is subtracted for further analysis of short term variations. Temporary velocity reductions occur at the time of ground shaking usually caused by earthquakes and are followed by a recovery. We present an empirical model that describes the seismic velocity variations based on continuous observations of the local ground acceleration. Our hypothesis is that not only the shaking of earthquakes provokes velocity drops, but any small vibrations continuously induce minor velocity variations that are immediately compensated by healing in the steady state. We show that the shaking effect is accumulated over time and best described by

Robustness of a TETRA base station receiver against intentional EMI

NARCIS (Netherlands)

van de Beek, G.S.; Leferink, Frank Bernardus Johannes

2015-01-01

Terrestrial trunked radio (TETRA) is a digital radio standard that was developed to meet the needs of professional mobile radio systems. TETRA is vulnerable to intentional electromagnetic interference (EMI) because of the wireless link. The EMI can easily be front door coupled to the base station

Back Radiation Suppression through a Semitransparent Ground Plane for a mm-Wave Patch Antenna

KAUST Repository

Klionovski, Kirill

2017-06-21

Omnidirectional radiation pattern with minimum backward radiation is highly desirable for base station antennas to minimize the multipath effects. Semitransparent ground planes have been used to reduce the backward radiation, but mostly with complicated non-uniform impedance distribution. In this work, we propose, for the first time, a round semitransparent ground plane of radius 0.8 λ with uniform impedance distribution that can improve the front-to-back ratio of a wideband patch antenna by 11.6 dB as compared to a similar sized metallic ground plane. The value of uniform impedance is obtained through analytical optimization by using asymptotic expressions in the Kirchhoff approximation of the radiation pattern of a toroidal wave scattered by a round semitransparent ground plane. The semitransparent ground plane has been realized using a low-cost carbon paste on a Kapton film. Experimental results match closely with those of simulations and validate the overall concept.

Ground-water flow in the surficial aquifer system and potential movement of contaminants from selected waste-disposal sites at Cecil Field Naval Air Station, Jacksonville, Florida

Science.gov (United States)

Halford, K.J.

1998-01-01

As part of the Installation Restoration Program, Cecil Field Naval Air Station, Jacksonville, Florida, is considering remedialaction alternatives to control the possible movement of contaminants from sites that may discharge to the surface. This requires a quantifiable understanding of ground-water flow through the surficial aquifer system and how the system will respond to any future stresses. The geologic units of interest in the study area consist of sediments of Holocene to Miocene age that extend from land surface to the base of the Hawthorn Group. The hydrogeology within the study area was determined from gamma-ray and geologists? logs. Ground-water flow through the surficial aquifer system was simulated with a seven-layer, finite-difference model that extended vertically from the water table to the top of the Upper Floridan aquifer. Results from the calibrated model were based on a long-term recharge rate of 6 inches per year, which fell in the range of 4 to 10 inches per year, estimated using stream hydrograph separation methods. More than 80 percent of ground-water flow circulates within the surficial-sand aquifer, which indicates that most contaminant movement also can be expected to move through the surficial-sand aquifer alone. The surficial-sand aquifer is the uppermost unit of the surficial aquifer system. Particle-tracking results showed that the distances of most flow paths were 1,500 feet or less from a given site to its discharge point. For an assumed effective porosity of 20 percent, typical traveltimes are 40 years or less. At all of the sites investigated, particles released 10 feet below the water table had shorter traveltimes than those released 40 feet below the water table. Traveltimes from contaminated sites to their point of discharge ranged from 2 to 300 years. The contributing areas of the domestic supply wells are not very extensive. The shortest traveltimes for particles to reach the domestic supply wells from their respective

Internet-to-orbit gateway and virtual ground station: A tool for space research and scientific outreach

Science.gov (United States)

Jaffer, Ghulam; Nader, Ronnie; Koudelka, Otto

2011-09-01

Students in higher education, and scientific and technological researchers want to communicate with the International Space Station (ISS), download live satellite images, and receive telemetry, housekeeping and science/engineering data from nano-satellites and larger spacecrafts. To meet this need the Ecuadorian Civilian Space Agency (EXA) has recently provided the civilian world with an internet-to-orbit gateway (Hermes-A/Minotaur) Space Flight Control Center (SFCC) available for public use. The gateway has a maximum range of tracking and detection of 22,000 km and sensitivity such that it can receive and discriminate the signals from a satellite transmitter with power˜0.1 W. The capability is enough to receive the faintest low-earth-orbit (LEO) satellites. This gateway virtually connects participating internet clients around the world to a remote satellite ground station (GS), providing a broad community for multinational cooperation. The goal of the GS is to lower financial and engineering barriers that hinder access to science and engineering data from orbit. The basic design of the virtual GS on a user side is based on free software suites. Using these and other software tools the GS is able to provide access to orbit for a multitude of users without each having to go through the costly setups. We present the design and implementation of the virtual GS in a higher education and scientific outreach settings. We also discuss the basic architecture of the single existing system and the benefits of a proposed distributed system. Details of the software tools and their applicability to synchronous round-the-world tracking, monitoring and processing performed by students and teams at Graz University of Technology, Austria, EXA-Ecuador, University of Michigan, USA and JAXA who have participated in various mission operations and have investigated real-time satellite data download and image acquisition and processing. Students and other remote users at these

GSM base station electromagnetic radiation and oxidative stress in rats.

Science.gov (United States)

Yurekli, Ali Ihsan; Ozkan, Mehmed; Kalkan, Tunaya; Saybasili, Hale; Tuncel, Handan; Atukeren, Pinar; Gumustas, Koray; Seker, Selim

2006-01-01

The ever increasing use of cellular phones and the increasing number of associated base stations are becoming a widespread source of nonionizing electromagnetic radiation. Some biological effects are likely to occur even at low-level EM fields. In this study, a gigahertz transverse electromagnetic (GTEM) cell was used as an exposure environment for plane wave conditions of far-field free space EM field propagation at the GSM base transceiver station (BTS) frequency of 945 MHz, and effects on oxidative stress in rats were investigated. When EM fields at a power density of 3.67 W/m2 (specific absorption rate = 11.3 mW/kg), which is well below current exposure limits, were applied, MDA (malondialdehyde) level was found to increase and GSH (reduced glutathione) concentration was found to decrease significantly (p < 0.0001). Additionally, there was a less significant (p = 0.0190) increase in SOD (superoxide dismutase) activity under EM exposure.

Silicon carbide optics for space and ground based astronomical telescopes

Science.gov (United States)

Robichaud, Joseph; Sampath, Deepak; Wainer, Chris; Schwartz, Jay; Peton, Craig; Mix, Steve; Heller, Court

2012-09-01

Silicon Carbide (SiC) optical materials are being applied widely for both space based and ground based optical telescopes. The material provides a superior weight to stiffness ratio, which is an important metric for the design and fabrication of lightweight space telescopes. The material also has superior thermal properties with a low coefficient of thermal expansion, and a high thermal conductivity. The thermal properties advantages are important for both space based and ground based systems, which typically need to operate under stressing thermal conditions. The paper will review L-3 Integrated Optical Systems - SSG’s (L-3 SSG) work in developing SiC optics and SiC optical systems for astronomical observing systems. L-3 SSG has been fielding SiC optical components and systems for over 25 years. Space systems described will emphasize the recently launched Long Range Reconnaissance Imager (LORRI) developed for JHU-APL and NASA-GSFC. Review of ground based applications of SiC will include supporting L-3 IOS-Brashear’s current contract to provide the 0.65 meter diameter, aspheric SiC secondary mirror for the Advanced Technology Solar Telescope (ATST).

No halt to the construction of Muelheim-Kaerlich nuclear power station

International Nuclear Information System (INIS)

Anon.

1975-01-01

The grounds upon which the judgment of Koblenz Administrative Court (Verwaltungsgericht) of 1-8-1975 - 7 L 14/75 - was based are now available. In this decision, the action of the city of Neuwied for restitution of the action to set aside (motion to stay the immediate execution of) the First Partial License for the construction of the 1,200 MW nuclear power station at Muelheim-Kaerlich was dismissed. The costs of the administrative procedures, including the extra-judicial costs of the persons summoned to appear in court, are imposed upon the applicant. The value in litigation of the procedures following the motion to stay proceedings was fixed at 50,000 DM. The sometimes contradictory grounds of paragraph II are given in full wording and commented upon. (orig./AK) [de

Development of a Space Station Operations Management System

Science.gov (United States)

Brandli, A. E.; McCandless, W. T.

To enhance the productivity of operations aboard the Space Station, a means must be provided to augment, and frequently to supplant, human effort in support of mission operations and management, both on the ground and onboard. The Operations Management System (OMS), under development at the Johnson Space Center, is one such means. OMS comprises the tools and procedures to facilitate automation of station monitoring, control, and mission planning tasks. OMS mechanizes, and hence rationalizes, execution of tasks traditionally performed by mission planners, the mission control center team, onboard System Management software, and the flight crew.

Development of a Space Station Operations Management System

Science.gov (United States)

Brandli, A. E.; Mccandless, W. T.

1988-01-01

To enhance the productivity of operations aboard the Space Station, a means must be provided to augment, and frequently to supplant, human effort in support of mission operations and management, both on the ground and onboard. The Operations Management System (OMS), under development at the Johnson Space Center, is one such means. OMS comprises the tools and procedures to facilitate automation of station monitoring, control, and mission planning tasks. OMS mechanizes, and hence rationalizes, execution of tasks traditionally performed by mission planners, the mission control center team, onboard System Management software, and the flight crew.

Stratospheric NO2 vertical profile retrieved from ground-based Zenith-Sky DOAS observations at Kiruna, Sweden

Science.gov (United States)

Gu, Myojeong; Enell, Carl-Fredrik; Hendrick, François; Pukite, Janis; Van Roozendael, Michel; Platt, Ulrich; Raffalski, Uwe; Wagner, Thomas

2014-05-01

Stratospheric NO2 destroys ozone and acts as a buffer against halogen-catalyzed ozone loss through the formation of reservoir species (ClONO2, BrONO2). Since the importance of both mechanisms depends on the altitude, the investigation of stratospheric NO2 vertical distribution can provide more insight into the role of nitrogen compounds in the destruction of ozone. Here we present stratospheric NO2 vertical profiles retrieved from twilight ground-based zenith-sky DOAS observations at Kiruna, Sweden (68.84°N, 20.41°E) covering 1997 - 2013 periods. This instrument observes zenith scattered sunlight. The sensitivity for stratospheric trace gases is highest during twilight due to the maximum altitude of the scattering profile and the light path through the stratosphere, which vary with the solar zenith angle. The profiling algorithm, based on the Optimal Estimation Method, has been developed by IASB-BIRA and successfully applied at other stations (Hendrick et al., 2004). The basic principle behind this profiling approach is that during twilight, the mean Rayleigh scattering altitude scans the stratosphere rapidly, providing height-resolved information on the absorption by stratospheric NO2. In this study, the long-term evolution of the stratospheric NO2 profile at polar latitude will be investigated. Hendrick, F., B. Barret, M. Van Roozendael, H. Boesch, A. Butz, M. De Mazière, F. Goutail, C. Hermans, J.-C. Lambert, K. Pfeilsticker, and J.-P. Pommereau, Retrieval of nitrogen dioxide stratospheric profiles from ground-based zenith-sky UV-visible observations: Validation of the technique through correlative comparisons, Atmospheric Chemistry and Physics, 4, 2091-2106, 2004

[Study on atmospheric VOCs in Gongga Mountain base station].

Science.gov (United States)

Zhang, Jun-Ke; Wang, Yue-Si; Wu, Fang-Kun; Sun, Jie

2012-12-01

Volatile organic compounds (VOCs) play important roles in the atmosphere as precursors of secondary air pollutants. The regional background concentrations and variation characteristics of VOCs in the atmosphere of southwestern China were studied. Meanwhile, a receptor model based on principal component analysis (PCA) was used to identify the major sources of VOCs. Weekly samples were collected in 2007 in the Gongga Mountain base station and analyzed with a three-stage preconcentration method coupled with GC-MS. The annual mean concentration of TVOCs and NMHCs were 9.40 x 10(-9) +/- 4.55 x 10(-9) and 7.73 x 10(-9) +/- 4.43 x 10(-9), respectively. Aromatic hydrocarbons provided the largest contribution to TVOCs (37.3%), follow by alkanes (30.0%) and halogenated hydrocarbons (19.8%), the smallest contribution was from alkenes (12.9%). Three major sources were resolved by the receptor model, traffic sources, biogenic sources and combustion sources. The seasonal variation of TVOCs in this area was obviously, and the order was autumn > winter > spring > summer. TVOCs concentration in autumn was very significantly higher than that in summer (P station emission characteristic.

Analysis of Synchronization Impairments for Cooperative Base Stations Using OFDM

Directory of Open Access Journals (Sweden)

Konstantinos Manolakis

2015-01-01

Full Text Available Base station cooperation is envisioned as a key technology for future cellular networks, as it has the potential to eliminate intercell interference and to enhance spectral efficiency. To date, there is still lack of understanding of how imperfect carrier and sampling frequency synchronization between transmitters and receivers limit the potential gains and what the actual system requirements are. In this paper, OFDM signal model is established for multiuser multicellular networks, describing the joint effect of multiple carrier and sampling frequency offsets. It is shown that the impact of sampling offsets is much smaller than the impact of carrier frequency offsets. The model is extended to the downlink of base-coordinated networks and closed-form expressions are derived for the mean power of users’ self-signal, interuser, and intercarrier interference, whereas it is shown that interuser interference is the main source of degradation. The SIR is inverse to the base stations’ carrier frequency variance and to the square of time since the last precoder update, whereas it grows with the number of base stations and drops with the number of users. Through user selection, the derived SIR upper bound can be approached. Finally, system design recommendations for meeting synchronization requirements are provided.

A precise time synchronization method for 5G based on radio-over-fiber network with SDN controller

Science.gov (United States)

He, Linkuan; Wei, Baoguo; Yang, Hui; Yu, Ao; Wang, Zhengyong; Zhang, Jie

2018-02-01

There is an increasing demand on accurate time synchronization with the growing bandwidth of network service for 5G. In 5G network, it's necessary for base station to achieve accurate time synchronization to guarantee the quality of communication. In order to keep accuracy time for 5G network, we propose a time synchronization system for satellite ground station based on radio-over-fiber network (RoFN) with software defined optical network (SDON) controller. The advantage of this method is to improve the accuracy of time synchronization of ground station. The IEEE 1588 time synchronization protocol can solve the problems of high cost and lack of precision. However, in the process of time synchronization, distortion exists during the transmission of digital time signal. RoF uses analog optical transmission links and therefore analog transmission can be implemented among ground stations instead of digital transmission, which means distortion and bandwidth waste in the process of digital synchronization can be avoided. Additionally, the thought of SDN, software defined network, can optimize RoFN with centralized control and simplifying base station. Related simulation had been carried out to prove its superiority.

Design and construction of Minokawai hydro-power station; Minokawai suiryoku hatsudensho no sekkei to seko

Energy Technology Data Exchange (ETDEWEB)

Kudo, A; Murakami, H; Hatano, K [Kansai Electric Power Co. Inc., Osaka (Japan)

1994-09-05

Minokawai power station is a plant with low head and large water quantity (output: 23.4MW) that utilizes Imawatari dam down the Kiso river. In constructing this power station, vertical drilling of about 33m in depth was executed in soft sedimentary rock area with uniaxial compression strength of 100kgf/cm{sup 2} or so. This report describes the geological condition in the drilling area and the outline of design and execution of corresponding landslide preventions. The drilling area mainly consists of tuff-containing sandstone and conglomerate with several weak layers such as lignite layers, and its stratum slopes gently from the mountain side to the river side. When the landslide preventions were designed, it was especially considered to secure stability of the drilling surface of earth filling as well as to control shear deformation along the lignite layer. Based on the two-dimensional elasto-plastic FEM analysis, structural design of landslide prevention walls and reinforcing methods using ground anchors and lock-bolts were determined. Construction works have been proceeded with as the ground behavior has been measured and controlled by setting many instruments such as insertion-type clinometers on the landslide preventions and the back ground. 2 refs., 18 figs., 5 tabs.

Fire Stations - 2007

Data.gov (United States)

Kansas Data Access and Support Center — Fire Station Locations in Kansas Any location where fire fighters are stationed at or based out of, or where equipment that such personnel use in carrying out their...

Fire Stations - 2009

Data.gov (United States)

Kansas Data Access and Support Center — Fire Stations in Kansas Any location where fire fighters are stationed or based out of, or where equipment that such personnel use in carrying out their jobs is...

Remote sensing of GHG over Paris megacity and Orléans forest using ground-based QualAir FTS and TCCON-Orléans

Science.gov (United States)

Te, Y.; Jeseck, P.; Da Costa, J.; Deutscher, N. M.; Warneke, T.; Notholt, J.

2012-04-01

In a growing world with more than 7 billion inhabitants and big emerging countries such as China, Brazil and India, emissions of anthropogenic pollutants are increasing continuously. Monitoring and control of atmospheric pollutants in megacities have become a major challenge for scientists and public health authorities in environmental research area. The QualAir platform at University Pierre et Marie Curie (UPMC), is an innovating experimental research platform dedicated to survey greenhouse gases (GHGs) and urban air quality. As one of the major instruments of the QualAir platform, the ground-based Fourier transform spectrometer (QualAir FTS, IFS 125HR model) analyses the composition of the urban atmosphere of Paris, which is the third European megacity. The continuous monitoring of atmospheric pollutants is essential to improve the understanding of urban air pollution processes. Associated with a sun-tracker, the QualAir remote sensing FTS operates in solar infrared absorption and enables to monitor many trace gases, and to follow up their variability in the Ile-de-France region. A description of the QualAir FTS will be given. Concentrations of atmospheric GHG, especially CO2 and CH4, are retrieved by the radiative transfer model PROFFIT. Located in the centre of Paris, the QualAir FTS can provide new and complementary urban measurements as compared to unpolluted ground-based stations of existing networks (NDACC and TCCON). The work made by LPMAA to join the TCCON network will also be presented. TCCON-Orléans is a ground-based FTS of the TCCON network located in the forest of Orléans (100 km south of Paris). Preliminary comparisons of GHGs measurements from both sites will be shown. Such ground-based information will help to better characterize regional GHGs, especially regarding anthropogenic emissions and trends.

Surface-Water, Water-Quality, and Ground-Water Assessment of the Municipio of Mayaguez, Puerto Rico, 1999-2002

Science.gov (United States)

Rodríguez-Martínez, Jesús; Santiago-Rivera, Luis; Guzman-Rios, Senen; Gómez-Gómez, Fernando; Oliveras-Feliciano, Mario L.

2004-01-01

The surface-water assessment portion of this study focused on analysis of low-flow characteristics in local streams and rivers, because the supply of safe drinking water was a critical issue during recent dry periods. Low-flow characteristics were evaluated at one continuous-record gaging station based on graphical curve-fitting techniques and log-Pearson Type III frequency curves. Estimates of low-flow characteristics for 20 partial-record stations were generated using graphical-correlation techniques. Flow-duration characteristics for the continuous- and partial-record stations were estimated using the relation curves developed for the low-flow study. Stream low-flow statistics document the general hydrology under current land use, water-use, and climatic conditions. A survey of streams and rivers utilized 37 sampling stations to evaluate the sanitary quality of about 165 miles of stream channels. River and stream samples for fecal coliform and fecal streptococcus analyses were collected on two occasions at base-flow conditions. Bacteriological analyses indicate that a significant portion of the stream reaches within the municipio of Mayaguez may have fecal coliform bacteria concentrations above the water-quality goal (standard) established by the Puerto Rico Environmental Quality Board (Junta de Calidad Ambiental de Puerto Rico) for inland surface waters. Sources of fecal contamination may include: illegal discharge of sewage to storm-water drains, malfunctioning sanitary sewer ejectors, clogged and leaking sewage pipes, septic tank leakage, unfenced livestock, and runoff from livestock pens. Long-term fecal coliform data from five sampling stations located within or in the vicinity of the municipio of Mayaguez have been in compliance with the water-quality goal for fecal coliform concentration established in July 1990. Geologic, topographic, soil, hydrogeologic, and streamflow data were compiled into a database and used to divide the municipio of Mayaguez into

Exposure level from selected base station tower around Kuala Nerus

African Journals Online (AJOL)

Health risk due to RF radiation exposure from base station tower (BST) has been debated for years leading to public concerns. Thus, this preliminary study aims to measure, evaluate and analyze the exposure level on three selected BST around Kuala Nerus. The measurement of exposure level in terms of voltage ...

Investigation on the real-time prediction of ground motions using seismic records observed in deep boreholes

Science.gov (United States)

Miyakoshi, H.; Tsuno, S.

2013-12-01

The present method of the EEW system installed in the railway field of Japan predicts seismic ground motions based on the estimated earthquake information about epicentral distances and magnitudes using initial P-waves observed on the surface. In the case of local earthquakes beneath the Tokyo Metropolitan Area, however, a method to directly predict seismic ground motions using P-waves observed in deep boreholes could issue EEWs more simply and surely. Besides, a method to predict seismic ground motions, using S-waves observed in deep boreholes and S-wave velocity structures beneath seismic stations, could show planar distributions of ground motions for train operation control areas in the aftermath of earthquakes. This information is available to decide areas in which the emergency inspection of railway structures should be performed. To develop those two methods, we investigated relationships between peak amplitudes on the surface and those in deep boreholes, using seismic records of KiK-net stations in the Kanto Basin. In this study, we used earthquake accelerograms observed in boreholes whose depths are deeper than the top face of Pre-Neogene basement and those on the surface at 12 seismic stations of KiK-net. We selected 243 local earthquakes whose epicenters are located around the Kanto Region. Those JMA magnitudes are in the range from 4.5 to 7.0. We picked the on-set of P-waves and S-waves using a vertical component and two horizontal components, respectively. Peak amplitudes of P-waves and S-waves were obtained using vertical components and vector sums of two horizontal components, respectively. We estimated parameters which represent site amplification factors beneath seismic stations, using peak amplitudes of S-waves observed in the deep borehole and those on the surface, to minimize the residuals between calculations by the theoretical equation and observations. Correlation coefficients between calculations and observations are high values in the range

Soyuz-TM-based interim Assured Crew Return Vehicle (ACRV) for the Space Station Freedom

Science.gov (United States)

Semenov, Yu. P.; Babkov, Oleg I.; Timchenko, Vladimir A.; Craig, Jerry W.

1993-01-01

The concept of using the available Soyuz-TM Assured Crew Return Vehicle (ACRV) spacecraft for the assurance of the safety of the Space Station Freedom (SSF) crew after the departure of the Space Shuttle from SSF was proposed by the NPO Energia and was accepted by NASA in 1992. The ACRV will provide the crew with the capability to evacuate a seriously injured/ill crewmember from the SSF to a ground-based care facility under medically tolerable conditions and with the capability for a safe evacuation from SSF in the events SSF becomes uninhabitable or the Space Shuttle flights are interrupted for a time that exceeds SSF ability for crew support and/or safe operations. This paper presents the main results of studies on Phase A (including studies on the service life of ACRV; spacecraft design and operations; prelaunch processing; mission support; safety, reliability, maintenance and quality and assurance; landing, and search/rescue operations; interfaces with the SSF and with Space Shuttle; crew accommodation; motion of orbital an service modules; and ACRV injection by the Expendable Launch Vehicles), along with the objectives of further work on the Phase B.

AFSC/ABL: ShoreZone Ground Stations, web-posted database in ArcGIS

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The web-posted Alaska Shore Station Database is a compilation of hundreds of intertidal sites that were visited and evaluated throughout the coastal waters of...

Integrated base stations and a method of transmitting data units in a communications system for mobile devices

NARCIS (Netherlands)

Bosch, H.G.P.; Mullender, Sape J.; Narlikar, G.J.; Samuel, L.G.; Yagati, L.N.

2006-01-01

Integrated base stations and a method of transmitting data units in a communications system for mobile devices. In one embodiment, an integrated base station includes a communications processor having a protocol stack configured with a media access control layer and a physical layer.

A large-scale measurement of electromagnetic fields near GSM base stations in Guangxi, China for risk communication.

Science.gov (United States)

Wu, Tongning; Shao, Qing; Yang, Lei; Qi, Dianyuan; Lin, Jun; Lin, Xiaojun; Yu, Zongying

2013-06-01

Radiofrequency (RF) electromagnetic field (EMF) exposure from wireless telecommunication base station antennae can lead to debates, conflicts or litigations among the adjacent residents if inappropriately managed. This paper presents a measurement campaign for the GSM band EMF exposure in the vicinity of 827 base station sites (totally 6207 measurement points) in Guangxi, China. Measurement specifications are designed for risk communication with the residents who previously complained of over-exposure. The EMF power densities with the global positioning system coordinate at each measured point were recorded. Compliance with the International Commission on Non-Ionizing Radiation Protection guidelines and Chinese environmental EMF safety standards was studied. The results show that the GSM band EMF level near the base stations is very low. The measurement results and the EMF risk communication procedures positively influence public perception of the RF EMF exposure from the base stations and promote the exchange of EMF exposure-related knowledge.

Single-station 6C beamforming

Science.gov (United States)

Nakata, N.; Hadziioannou, C.; Igel, H.

2017-12-01

Six-component measurements of seismic ground motion provide a unique opportunity to identify and decompose seismic wavefields into different wave types and incoming azimuths, as well as estimate structural information (e.g., phase velocity). By using the relationship between the transverse component and vertical rotational motion for Love waves, we can find the incident azimuth of the wave and the phase velocity. Therefore, when we scan the entire range of azimuth and slownesses, we can process the seismic waves in a similar way to conventional beamforming processing, without using a station array. To further improve the beam resolution, we use the distribution of amplitude ratio between translational and rotational motions at each time sample. With this beamforming, we decompose multiple incoming waves by azimuth and phase velocity using only one station. We demonstrate this technique using the data observed at Wettzell (vertical rotational motion and 3C translational motions). The beamforming results are encouraging to extract phase velocity at the location of the station, apply to oceanic microseism, and to identify complicated SH wave arrivals. We also discuss single-station beamforming using other components (vertical translational and horizontal rotational components). For future work, we need to understand the resolution limit of this technique, suitable length of time windows, and sensitivity to weak motion.

Astrid-2 and ground-based observations of the auroral bulge in the middle of the nightside convection throat

Directory of Open Access Journals (Sweden)

G. T. Marklund

2001-06-01

Full Text Available Results concerning the electrodynamics of the nightside auroral bulge are presented based on simultaneous satellite and ground-based observations. The satellite data include Astrid-2 measurements of electric fields, currents and particles from a midnight auroral oval crossing and Polar UVI images of the large-scale auroral distribution. The ground-based observations include STARE and SuperDARN electric fields and magnetic records from the Greenland and MIRACLE magnetometer network, the latter including stations from northern Scandinavia north to Svalbard. At the time of the Astrid-2 crossing the ground-based data reveal intense electrojet activity, both to the east and west of the Astrid-2 trajectory, related to the Polar observations of the auroral bulge but not necessarily to a typical substorm. The energetic electron fluxes measured by Astrid-2 across the auroral oval were generally weak being consistent with a gap observed in the auroral luminosity distribution. The electric field across the oval was directed westward, intensifying close to the poleward boundary followed by a decrease in the polar cap. The combined observations suggests that Astrid-2 was moving close to the separatrix between the dusk and dawn convection cells in a region of low conductivity. The constant westward direction of the electric field across the oval indicates that current continuity was maintained, not by polarisation electric fields (as in a Cowling channel, but solely by localized up- and downward field-aligned currents in good agreement with the Astrid-2 magnetometer data. The absence of a polarisation electric field and thus of an intense westward closure current between the dawn and dusk convection cells is consistent with the relatively weak precipitation and low conductivity in the convection throat. Thus, the Cowling current model is not adequate for describing the electrodynamics of the nightside auroral bulge treated here.Key words. Ionosphere (auroral

Sounding rocket experiments during the IMS period at Syowa Station, Antarctica

International Nuclear Information System (INIS)

Hirasawa, T.; Nagata, T.

1979-01-01

During IMS Period, 19 sounding rockets were launched into auroras at various stages of polar substorms from Syowa Station (Geomag. lat. = -69.6 0 , Geomag. log. = 77.1 0 ), Antarctica. Through the successful rocket flights, the significant physical quantities in auroras were obtained: 19 profiles of electron density and temperature, 11 energy spectra of precipitating electrons, 15 frequency spectra of VLF and HF plasma waves and 4 vertical profiles of electric and magnetic fields. These rocket data have been analyzed and compared with the coordinated ground-based observation data for studies of polar substorms. (author)

A Technical Approach to the Evaluation of Radiofrequency Radiation Emissions from Mobile Telephony Base Stations

OpenAIRE

Buckus, Raimondas; Struk?inskien?, Birute; Raistenskis, Juozas; Stukas, Rimantas; ?idlauskien?, Aurelija; ?erkauskien?, Rimant?; Isopescu, Dorina Nicolina; Stabryla, Jan; Cretescu, Igor

2017-01-01

During the last two decades, the number of macrocell mobile telephony base station antennas emitting radiofrequency (RF) electromagnetic radiation (EMR) in residential areas has increased significantly, and therefore much more attention is being paid to RF EMR and its effects on human health. Scientific field measurements of public exposure to RF EMR (specifically to radio frequency radiation) from macrocell mobile telephony base station antennas and RF electromagnetic field (EMF) intensity p...

High energy astrophysics with ground-based gamma ray detectors

International Nuclear Information System (INIS)

Aharonian, F; Buckley, J; Kifune, T; Sinnis, G

2008-01-01

Recent advances in ground-based gamma ray astronomy have led to the discovery of more than 70 sources of very high energy (E γ ≥ 100 GeV) gamma rays, falling into a number of source populations including pulsar wind nebulae, shell type supernova remnants, Wolf-Rayet stars, giant molecular clouds, binary systems, the Galactic Center, active galactic nuclei and 'dark' (yet unidentified) galactic objects. We summarize the history of TeV gamma ray astronomy up to the current status of the field including a description of experimental techniques and highlight recent astrophysical results. We also discuss the potential of ground-based gamma ray astronomy for future discoveries and describe possible directions for future instrumental developments

Transient Simulations in Hydropower Stations Based on a Novel Turbine Boundary

Directory of Open Access Journals (Sweden)

Yanna Liu

2016-01-01

Full Text Available Most accidents in hydropower stations happened during transient processes; thus, simulation of these processes is important for station design and safety operation. This study establishes a mathematical model of the transient process in hydropower stations and presents a new method to calculate the hydraulic turbine boundary based on an error function of the rotational speed. The mathematical derivation shows that the error function along the equal-opening characteristic curve is monotonic and has opposite signs at the two sides, which means that a unique solution exists to make the error function null. Thus, iteration of the transient simulation is unique and monotonous, which avoids iterative convergence or false solution and improves the solution efficiency compared with traditional methods. Simulation of an engineering case illustrates that the results obtained by the error function are reasonable. Then, the accuracy and feasibility of the mathematical model using the proposed solution are verified by comparison with model and field tests.

Throughput of Cellular Systems with Conferencing Mobiles and Cooperative Base Stations

Directory of Open Access Journals (Sweden)

Somekh O

2008-01-01

Full Text Available This paper considers an enhancement to multicell processing for the uplink of a cellular system, whereby the mobile stations are allowed to exchange messages on orthogonal channels of fixed capacity (conferencing. Both conferencing among mobile stations in different cells and in the same cell (inter- and intracell conferencing, resp. are studied. For both cases, it is shown that a rate-splitting transmission strategy, where part of the message is exchanged on the conferencing channels and then transmitted cooperatively to the base stations, is capacity achieving for sufficiently large conferencing capacity. In case of intercell conferencing, this strategy performs convolutional pre-equalization of the signal encoding the common messages in the spatial domain, where the number of taps of the finite-impulse response equalizer depends on the number of conferencing rounds. Analysis in the low signal-to-noise ratio regime and numerical results validate the advantages of conferencing as a complementary technology to multicell processing.

A plan for location calibration of IMS stations and near Kazakhstan

International Nuclear Information System (INIS)

Richards, P.G.; Kim, W.-Yo.; Khalturin, V.I.

2001-01-01

For purposes of monitoring compliance with the Comprehensive Nuclear Test-Ban Treaty, it is desirable to be able to locate seismic events routinely to within an uncertainty not greater than 1000 square km. From more than five years of experience with publication of the Reviewed Event Bulletin (REB) by the Prototype International Data Centre (PIDC), resulting in estimated locations for more than 100,000 seismic events, it is apparent that improved location accuracy is needed in order to reduce uncertainties below 1000 square km. In this paper, we outline a three-year program of applied research which commenced in March 2000 and which has the goal of achieving improved REB locations based upon data to be contributed to the International Data Centre from 30 IMS stations in Eastern Asia. Our first efforts will focus on the four IMS seismographic stations in Kazakhstan (AKT, BRV, KUR, MAK), together with IMS stations ZAL in Russia and AAK in Kyrgyzstan. Following the recommendations of two 'IMS Location Calibration Workshops' held in Oslo, Norway, in 1999 and 2000, our approach is to generate station-specific travel times for each observable seismic phase, as a function of distance and azimuth (and depth, where possible). Such travel times are obtained on the basis of (i) early studies based mainly on earthquake data (e.g. Nersesov and Rautian, 1964), (ii) Deep Seismic Sounding, and (iii) recent studies of nuclear and chemical explosions. We are also using (iv) an empirical approach in which phases are picked at IMS stations, for so-called Ground Truth events whose location is known quite accurately on the basis of additional data, obtained for example from local and regional networks. (author)

An evaluation of IASI-NH3 with ground-based Fourier transform infrared spectroscopy measurements

Directory of Open Access Journals (Sweden)

E. Dammers

2016-08-01

Full Text Available Global distributions of atmospheric ammonia (NH3 measured with satellite instruments such as the Infrared Atmospheric Sounding Interferometer (IASI contain valuable information on NH3 concentrations and variability in regions not yet covered by ground-based instruments. Due to their large spatial coverage and (bi-daily overpasses, the satellite observations have the potential to increase our knowledge of the distribution of NH3 emissions and associated seasonal cycles. However the observations remain poorly validated, with only a handful of available studies often using only surface measurements without any vertical information. In this study, we present the first validation of the IASI-NH3 product using ground-based Fourier transform infrared spectroscopy (FTIR observations. Using a recently developed consistent retrieval strategy, NH3 concentration profiles have been retrieved using observations from nine Network for the Detection of Atmospheric Composition Change (NDACC stations around the world between 2008 and 2015. We demonstrate the importance of strict spatio-temporal collocation criteria for the comparison. Large differences in the regression results are observed for changing intervals of spatial criteria, mostly due to terrain characteristics and the short lifetime of NH3 in the atmosphere. The seasonal variations of both datasets are consistent for most sites. Correlations are found to be high at sites in areas with considerable NH3 levels, whereas correlations are lower at sites with low atmospheric NH3 levels close to the detection limit of the IASI instrument. A combination of the observations from all sites (Nobs = 547 give a mean relative difference of −32.4 ± (56.3 %, a correlation r of 0.8 with a slope of 0.73. These results give an improved estimate of the IASI-NH3 product performance compared to the previous upper-bound estimates (−50 to +100 %.

Solar energy prediction and verification using operational model forecasts and ground-based solar measurements

International Nuclear Information System (INIS)

Kosmopoulos, P.G.; Kazadzis, S.; Lagouvardos, K.; Kotroni, V.; Bais, A.

2015-01-01

The present study focuses on the predictions and verification of these predictions of solar energy using ground-based solar measurements from the Hellenic Network for Solar Energy and the National Observatory of Athens network, as well as solar radiation operational forecasts provided by the MM5 mesoscale model. The evaluation was carried out independently for the different networks, for two forecast horizons (1 and 2 days ahead), for the seasons of the year, for varying solar elevation, for the indicative energy potential of the area, and for four classes of cloud cover based on the calculated clearness index (k_t): CS (clear sky), SC (scattered clouds), BC (broken clouds) and OC (overcast). The seasonal dependence presented relative rRMSE (Root Mean Square Error) values ranging from 15% (summer) to 60% (winter), while the solar elevation dependence revealed a high effectiveness and reliability near local noon (rRMSE ∼30%). An increment of the errors with cloudiness was also observed. For CS with mean GHI (global horizontal irradiance) ∼ 650 W/m"2 the errors are 8%, for SC 20% and for BC and OC the errors were greater (>40%) but correspond to much lower radiation levels (<120 W/m"2) of consequently lower energy potential impact. The total energy potential for each ground station ranges from 1.5 to 1.9 MWh/m"2, while the mean monthly forecast error was found to be consistently below 10%. - Highlights: • Long term measurements at different atmospheric cases are needed for energy forecasting model evaluations. • The total energy potential at the Greek sites presented ranges from 1.5 to 1.9 MWh/m"2. • Mean monthly energy forecast errors are within 10% for all cases analyzed. • Cloud presence results of an additional forecast error that varies with the cloud cover.

Evaluation of stability of foundation ground during earthquake, (1)

International Nuclear Information System (INIS)

Nishi, Koichi; Kanatani, Mamoru; Matsui, Ietaka; Touma, Jun-ichi

1986-01-01

The Central Research Institute of Electric Power Industry has advanced the research on the new location technology for nuclear power stations in order to cope with the lack of sites expected in near future. The sites on rock mass are usually used for nuclear power stations, but the location on quaternary ground, particularly on gravel ground, is one of such new technology, to which attention has been paid. It has been pointed out that this location has the advantage in the earthquake response of reactor buildings and equipment, and the prospect to ensure the stability by lowering underground water level and pile penetration has been obtained, therefore, the possibility of its realization is high. At present, the research aiming at the establishment of the method of evaluating foundation ground stability is in progress, and it is expected that the quantitative evaluation means for the aseismatic stability of quaternary ground is obtained. In this paper, the analysis techniques for forecasting the amount of subsidence at the time of earthquakes occurring accompanying the generation of excessive pore water pressure and its disappearance are reported. Also the applicability of the forecasting techniques was experimentally verified. (Kako, I.)

A computer-based system for environmental impact assessment (EIA) applications to energy power stations in Turkey: CEDINFO

Energy Technology Data Exchange (ETDEWEB)

Say, Nuriye Peker; Yuecel, Muzaffer [Cukurova University, Adana (Turkey). Department of Landscape Architecture; Yilmazer, Mehmet [Bogazici University, Kandilli, Istanbul (Turkey). Kandilli Observatory and Earthquake Research Institute

2007-12-15

Environmental impact assessment (EIA) is a tool for decision makers to take into account the possible effects of a proposed project on the environment and is also a process for collecting the data related to a project design and project area. Different techniques are used for the EIA process. In recent years, including the design and development of databases, classification systems, computer models and expert systems have been used extensively in impact assessment studies. Knowledge-based systems referred to as expert systems and different computer-based systems are an emerging technology in information processing and are becoming increasingly useful tools in different applications areas including EIA studies. Their use for EIA has been quite limited in developing countries, because of the constraints on resources, particularly in expertise and data. In this study, a knowledge-based software - CEDINFO - developed by authors was introduced. CEDINFO to be used for EIA practices on energy-generating stations was designed based on the legal EIA process in Turkey. According to the EIA Regulation enacted in Turkey in 1993, energy-generating stations (thermal power station, hydraulic station, nuclear station) in different categories require mandatory EIA reports duly approved by The Ministry of Environment and Forestry before their construction. CEDINFO primarily aims to provide educational support for EIA practices and decision-makers on energy-generating stations. (author)

A computer-based system for environmental impact assessment (EIA) applications to energy power stations in Turkey: CEDINFO

Energy Technology Data Exchange (ETDEWEB)

Nuriye Peker Say; Muzaffer Yucel; Mehmet Yilmazer [Cukurova University, Adana (Turkey). Department of Landscape Architecture

2007-12-15

Environmental impact assessment (EIA) is a tool to enable decision makers to account for the possible effects of a proposed project on the environment and is also a process for collecting the data related to a project design and project area. Different techniques are used for the EIA process. In recent years, including the design and development of databases, classification systems, computer models and expert systems have been used extensively in impact assessment studies. Knowledge-based systems referred to as expert systems and different computer-based systems are an emerging technology in information processing and are becoming increasingly useful tools in different applications areas including EIA studies. Their use for EIA has been quite limited in developing countries, because of the constraints on resources, particularly in expertise and data. In this study, a knowledge-based software CEDINFO developed by authors was introduced. CEDINFO to be used for EIA practices on energy-generating stations was designed based on the legal EIA process in Turkey. According to the EIA Regulation enacted in Turkey in 1993, energy-generating stations (thermal power stations, hydroelectric power stations, nuclear power stations) in different categories require mandatory EIA reports duly approved by The Ministry of Environment and Forestry before their construction. CEDINFO primarily aims to provide educational support for EIA practices and decision-makers on energy-generating stations. 23 refs., 5 figs., 2 tabs.

A computer-based system for environmental impact assessment (EIA) applications to energy power stations in Turkey: CEDINFO

International Nuclear Information System (INIS)

Say, Nuriye Peker; Yuecel, Muzaffer; Yilmazer, Mehmet

2007-01-01

Environmental impact assessment (EIA) is a tool for decision makers to take into account the possible effects of a proposed project on the environment and is also a process for collecting the data related to a project design and project area. Different techniques are used for the EIA process. In recent years, including the design and development of databases, classification systems, computer models and expert systems have been used extensively in impact assessment studies. Knowledge-based systems referred to as expert systems and different computer-based systems are an emerging technology in information processing and are becoming increasingly useful tools in different applications areas including EIA studies. Their use for EIA has been quite limited in developing countries, because of the constraints on resources, particularly in expertise and data. In this study, a knowledge-based software-CEDINFO-developed by authors was introduced. CEDINFO to be used for EIA practices on energy-generating stations was designed based on the legal EIA process in Turkey. According to the EIA Regulation enacted in Turkey in 1993, energy-generating stations (thermal power station, hydraulic station, nuclear station) in different categories require mandatory EIA reports duly approved by The Ministry of Environment and Forestry before their construction. CEDINFO primarily aims to provide educational support for EIA practices and decision-makers on energy-generating stations

Ground-based Observations and Atmospheric Modelling of Energetic Electron Precipitation Effects on Antarctic Mesospheric Chemistry

Science.gov (United States)

Newnham, D.; Clilverd, M. A.; Horne, R. B.; Rodger, C. J.; Seppälä, A.; Verronen, P. T.; Andersson, M. E.; Marsh, D. R.; Hendrickx, K.; Megner, L. S.; Kovacs, T.; Feng, W.; Plane, J. M. C.

2016-12-01

The effect of energetic electron precipitation (EEP) on the seasonal and diurnal abundances of nitric oxide (NO) and ozone in the Antarctic middle atmosphere during March 2013 to July 2014 is investigated. Geomagnetic storm activity during this period, close to solar maximum, was driven primarily by impulsive coronal mass ejections. Near-continuous ground-based atmospheric measurements have been made by a passive millimetre-wave radiometer deployed at Halley station (75°37'S, 26°14'W, L = 4.6), Antarctica. This location is directly under the region of radiation-belt EEP, at the extremity of magnetospheric substorm-driven EEP, and deep within the polar vortex during Austral winter. Superposed epoch analyses of the ground based data, together with NO observations made by the Solar Occultation For Ice Experiment (SOFIE) onboard the Aeronomy of Ice in the Mesosphere (AIM) satellite, show enhanced mesospheric NO following moderate geomagnetic storms (Dst ≤ -50 nT). Measurements by co-located 30 MHz riometers indicate simultaneous increases in ionisation at 75-90 km directly above Halley when Kp index ≥ 4. Direct NO production by EEP in the upper mesosphere, versus downward transport of NO from the lower thermosphere, is evaluated using a new version of the Whole Atmosphere Community Climate Model incorporating the full Sodankylä Ion Neutral Chemistry Model (WACCM SIC). Model ionization rates are derived from the Polar orbiting Operational Environmental Satellites (POES) second generation Space Environment Monitor (SEM 2) Medium Energy Proton and Electron Detector instrument (MEPED). The model data are compared with observations to quantify the impact of EEP on stratospheric and mesospheric odd nitrogen (NOx), odd hydrogen (HOx), and ozone.

Energy-Saving Optimization of Water Supply Pumping Station Life Cycle Based on BIM Technology

Science.gov (United States)

Qun, Miao; Wang, Jiayuan; Liu, Chao

2017-12-01

In the urban water supply system, pump station is the main unit of energy consumption. In the background of pushing forward the informatization in China, using BIM technology in design, construction and operations of water supply pumping station, can break through the limitations of the traditional model and effectively achieve the goal of energy conservation and emissions reduction. This work researches the way to solve energy-saving optimization problems in the process of whole life cycle of water supply pumping station based on BIM technology, and put forward the feasible strategies of BIM application in order to realize the healthy and sustainable development goals by establishing the BIM model of water supply pumping station of Qingdao Guzhenkou water supply project.

A Bayesian and Physics-Based Ground Motion Parameters Map Generation System

Science.gov (United States)

Ramirez-Guzman, L.; Quiroz, A.; Sandoval, H.; Perez-Yanez, C.; Ruiz, A. L.; Delgado, R.; Macias, M. A.; Alcántara, L.

2014-12-01

We present the Ground Motion Parameters Map Generation (GMPMG) system developed by the Institute of Engineering at the National Autonomous University of Mexico (UNAM). The system delivers estimates of information associated with the social impact of earthquakes, engineering ground motion parameters (gmp), and macroseismic intensity maps. The gmp calculated are peak ground acceleration and velocity (pga and pgv) and response spectral acceleration (SA). The GMPMG relies on real-time data received from strong ground motion stations belonging to UNAM's networks throughout Mexico. Data are gathered via satellite and internet service providers, and managed with the data acquisition software Earthworm. The system is self-contained and can perform all calculations required for estimating gmp and intensity maps due to earthquakes, automatically or manually. An initial data processing, by baseline correcting and removing records containing glitches or low signal-to-noise ratio, is performed. The system then assigns a hypocentral location using first arrivals and a simplified 3D model, followed by a moment tensor inversion, which is performed using a pre-calculated Receiver Green's Tensors (RGT) database for a realistic 3D model of Mexico. A backup system to compute epicentral location and magnitude is in place. A Bayesian Kriging is employed to combine recorded values with grids of computed gmp. The latter are obtained by using appropriate ground motion prediction equations (for pgv, pga and SA with T=0.3, 0.5, 1 and 1.5 s ) and numerical simulations performed in real time, using the aforementioned RGT database (for SA with T=2, 2.5 and 3 s). Estimated intensity maps are then computed using SA(T=2S) to Modified Mercalli Intensity correlations derived for central Mexico. The maps are made available to the institutions in charge of the disaster prevention systems. In order to analyze the accuracy of the maps, we compare them against observations not considered in the

Estimating Ground-Level PM2.5 by Fusing Satellite and Station Observations: A Geo-Intelligent Deep Learning Approach

Science.gov (United States)

Li, Tongwen; Shen, Huanfeng; Yuan, Qiangqiang; Zhang, Xuechen; Zhang, Liangpei

2017-12-01

Fusing satellite observations and station measurements to estimate ground-level PM2.5 is promising for monitoring PM2.5 pollution. A geo-intelligent approach, which incorporates geographical correlation into an intelligent deep learning architecture, is developed to estimate PM2.5. Specifically, it considers geographical distance and spatiotemporally correlated PM2.5 in a deep belief network (denoted as Geoi-DBN). Geoi-DBN can capture the essential features associated with PM2.5 from latent factors. It was trained and tested with data from China in 2015. The results show that Geoi-DBN performs significantly better than the traditional neural network. The out-of-sample cross-validation R2 increases from 0.42 to 0.88, and RMSE decreases from 29.96 to 13.03 μg/m3. On the basis of the derived PM2.5 distribution, it is predicted that over 80% of the Chinese population live in areas with an annual mean PM2.5 of greater than 35 μg/m3. This study provides a new perspective for air pollution monitoring in large geographic regions.

Locating techniques for nuclear power stations

International Nuclear Information System (INIS)

Hayashi, Masao

1983-01-01

The basic thought in locating nuclear power stations is to examine carefully the suitability of sites and the safety of plants, and in the end, to perfect the safety of public. In Japan, effort is exerted to obtain the trust of local people by carrying out investigation, research and examination from respective standpoints of the government, institutes and industries. The author has engaged in the standardization of the investigation, test and analysis regarding the aseismatic capability of ground, the verifying project in Tadotsu of the coupled vibration of ground and structures, the evaluation of the performance of large vibration tables, the future concept of new locating procedure and so on in the last more than ten years. The technological classification of ground, the technological meaning of active faults, the procedure of the aseismatic design of plants, the difference of earthquake input force according to various locating methods, 12 rules regarding the attenuation of vibration of ground, and the concept of new locating method in the 21st century are explained. As the new locating techniques applicable to central Japan, diluvial ground location, floating location in tunnels, underground location, offshore location and so on must be promoted. (Kako, I.)

UMTS base station-like exposure, well-being, and cognitive performance.

Science.gov (United States)

Regel, Sabine J; Negovetic, Sonja; Röösli, Martin; Berdiñas, Veronica; Schuderer, Jürgen; Huss, Anke; Lott, Urs; Kuster, Niels; Achermann, Peter

2006-08-01

Radio-frequency electromagnetic fields (RF EMF) of mobile communication systems are widespread in the living environment, yet their effects on humans are uncertain despite a growing body of literature. We investigated the influence of a Universal Mobile Telecommunications System (UMTS) base station-like signal on well-being and cognitive performance in subjects with and without self-reported sensitivity to RF EMF. We performed a controlled exposure experiment (45 min at an electric field strength of 0, 1, or 10 V/m, incident with a polarization of 45 degrees from the left back side of the subject, weekly intervals) in a randomized, double-blind crossover design. A total of 117 healthy subjects (33 self-reported sensitive, 84 nonsensitive subjects) participated in the study. We assessed well-being, perceived field strength, and cognitive performance with questionnaires and cognitive tasks and conducted statistical analyses using linear mixed models. Organ-specific and brain tissue-specific dosimetry including uncertainty and variation analysis was performed. In both groups, well-being and perceived field strength were not associated with actual exposure levels. We observed no consistent condition-induced changes in cognitive performance except for two marginal effects. At 10 V/m we observed a slight effect on speed in one of six tasks in the sensitive subjects and an effect on accuracy in another task in nonsensitive subjects. Both effects disappeared after multiple end point adjustment. In contrast to a recent Dutch study, we could not confirm a short-term effect of UMTS base station-like exposure on well-being. The reported effects on brain functioning were marginal and may have occurred by chance. Peak spatial absorption in brain tissue was considerably smaller than during use of a mobile phone. No conclusions can be drawn regarding short-term effects of cell phone exposure or the effects of long-term base station-like exposure on human health.

SCIENTIFIC EFFICIENCY OF GROUND-BASED TELESCOPES

International Nuclear Information System (INIS)

Abt, Helmut A.

2012-01-01

I scanned the six major astronomical journals of 2008 for all 1589 papers that are based on new data obtained from ground-based optical/IR telescopes worldwide. Then I collected data on numbers of papers, citations to them in 3+ years, the most-cited papers, and annual operating costs. These data are assigned to four groups by telescope aperture. For instance, while the papers from telescopes with an aperture >7 m average 1.29 more citations than those with an aperture of 2 to 7 m) telescopes. I wonder why the large telescopes do so relatively poorly and suggest possible reasons. I also found that papers based on archival data, such as the Sloan Digital Sky Survey, produce 10.6% as many papers and 20.6% as many citations as those based on new data. Also, the 577.2 papers based on radio data produced 36.3% as many papers and 33.6% as many citations as the 1589 papers based on optical/IR telescopes.

A large-scale measurement of electromagnetic fields near GSM base stations in Guangxi, China for risk communication

International Nuclear Information System (INIS)

Wu, T.; Shao, Q.; Yang, L.; Qi, D.; Lin, J.; Lin, X.; Yu, Z.

2013-01-01

Radiofrequency (RF) electromagnetic field (EMF) exposure from wireless telecommunication base station antennae can lead to debates, conflicts or litigations among the adjacent residents if inappropriately managed. This paper presents a measurement campaign for the GSM band EMF exposure in the vicinity of 827 base station sites (totally 6207 measurement points) in Guangxi, China. Measurement specifications are designed for risk communication with the residents who previously complained of over-exposure. The EMF power densities with the global positioning system coordinate at each measured point were recorded. Compliance with the International Commission on Non-Ionizing Radiation Protection guidelines and Chinese environmental EMF safety standards was studied. The results show that the GSM band EMF level near the base stations is very low. The measurement results and the EMF risk communication procedures positively influence public perception of the RF EMF exposure from the base stations and promote the exchange of EMF exposure-related knowledge. (authors)

Automatic Scheduling and Planning (ASAP) in future ground control systems

Science.gov (United States)

Matlin, Sam

1988-01-01

This report describes two complementary approaches to the problem of space mission planning and scheduling. The first is an Expert System or Knowledge-Based System for automatically resolving most of the activity conflicts in a candidate plan. The second is an Interactive Graphics Decision Aid to assist the operator in manually resolving the residual conflicts which are beyond the scope of the Expert System. The two system designs are consistent with future ground control station activity requirements, support activity timing constraints, resource limits and activity priority guidelines.

Ground-Based VIS/NIR Reflectance Spectra of 25143 Itokawa: What Hayabusa will See and How Ground-Based Data can Augment Analyses

Science.gov (United States)

Vilas, Faith; Abell, P. A.; Jarvis, K. S.

2004-01-01

Planning for the arrival of the Hayabusa spacecraft at asteroid 25143 Itokawa includes consideration of the expected spectral information to be obtained using the AMICA and NIRS instruments. The rotationally-resolved spatial coverage the asteroid we have obtained with ground-based telescopic spectrophotometry in the visible and near-infrared can be utilized here to address expected spacecraft data. We use spectrophotometry to simulate the types of data that Hayabusa will receive with the NIRS and AMICA instruments, and will demonstrate them here. The NIRS will cover a wavelength range from 0.85 m, and have a dispersion per element of 250 Angstroms. Thus, we are limited in coverage of the 1.0 micrometer and 2.0 micrometer mafic silicate absorption features. The ground-based reflectance spectra of Itokawa show a large component of olivine in its surface material, and the 2.0 micrometer feature is shallow. Determining the olivine to pyroxene abundance ratio is critically dependent on the attributes of the 1.0- and 2.0 micrometer features. With a cut-off near 2,1 micrometer the longer edge of the 2.0- feature will not be obtained by NIRS. Reflectance spectra obtained using ground-based telescopes can be used to determine the regional composition around space-based spectral observations, and possibly augment the longer wavelength spectral attributes. Similarly, the shorter wavelength end of the 1.0 micrometer absorption feature will be partially lost to the NIRS. The AMICA filters mimic the ECAS filters, and have wavelength coverage overlapping with the NIRS spectral range. We demonstrate how merging photometry from AMICA will extend the spectral coverage of the NIRS. Lessons learned from earlier spacecraft to asteroids should be considered.

Performance Based Criteria for Ship Collision and Grounding

DEFF Research Database (Denmark)

Pedersen, Preben Terndrup

2009-01-01

The paper outlines a probabilistic procedure whereby the maritime industry can develop performance based rules to reduce the risk associated with human, environmental and economic costs of collision and grounding events and identify the most economic risk control options associated with prevention...

Effect of electromagnetic radiations from mobile phone base stations on general health and salivary function

OpenAIRE

Singh, Kushpal; Nagaraj, Anup; Yousuf, Asif; Ganta, Shravani; Pareek, Sonia; Vishnani, Preeti

2016-01-01

Objective: Cell phones use electromagnetic, nonionizing radiations in the microwave range, which some believe may be harmful to human health. The present study aimed to determine the effect of electromagnetic radiations (EMRs) on unstimulated/stimulated salivary flow rate and other health-related problems between the general populations residing in proximity to and far away from mobile phone base stations. Materials and Methods: A total of four mobile base stations were randomly selected from...

Unidirectional Magneto-Electric Dipole Antenna for Base Station: A Review

Science.gov (United States)

Idayachandran, Govindanarayanan; Nakkeeran, Rangaswamy

2018-04-01

Unidirectional base station antenna design using Magneto-Electric Dipole (MED) has created enormous interest among the researchers due to its excellent radiation characteristics like low back radiation, symmetrical radiation at E-plane and H-plane compared to conventional patch antenna. Generally, dual polarized antennas are used to increase channel capacity and reliability of the communication systems. In order to serve the evolving mobile communication standards like long term evolution LTE and beyond, unidirectional dual polarized MED antenna are required to have broad impedance bandwidth, broad half power beamwidth, high port isolation, low cross polarization level, high front to back ratio and high gain. In this paper, the critical electrical requirements of the base station antenna and frequently used frequency bands for modern mobile communication have been presented. It is followed by brief review on broadband patch antenna and discussion on complementary antenna concepts. Finally, the performance of linearly polarized and dual polarized magneto-electric dipole antennas along with their feeding techniques are discussed and summarized. Also, design and modeling of developed MED antenna is presented.

Managing NASA's International Space Station Logistics and Maintenance Program

Science.gov (United States)

Butina, Anthony

2001-01-01

The International Space Station's Logistics and Maintenance program has had to develop new technologies and a management approach for both space and ground operations. The ISS will be a permanently manned orbiting vehicle that has no landing gear, no international borders, and no organizational lines - it is one Station that must be supported by one crew, 24 hours a day, 7 days a week, 365 days a year. It flies partially assembled for a number of years before it is finally completed in 2006. It has over 6,000 orbital replaceable units (ORU), and spare parts which number into the hundreds of thousands, from 127 major US vendors and 70 major international vendors. From conception to operation, the ISS requires a unique approach in all aspects of development and operations. Today the dream is coming true; hardware is flying and hardware is failing. The system has been put into place to support the Station for both space and ground operations. It started with the basic support concept developed for Department of Defense systems, and then it was tailored for the unique requirements of a manned space vehicle. Space logistics is a new concept that has wide reaching consequences for both space travel and life on Earth. This paper discusses what type of organization has been put into place to support both space and ground operations and discusses each element of that organization. In addition, some of the unique operations approaches this organization has had to develop is discussed.

Analysis of the effect of mobile phone base station antenna loading on localized SAR and its consequences for measurements.

Science.gov (United States)

Hansson, Björn; Thors, Björn; Törnevik, Christer

2011-12-01

In this work, the effect of antenna element loading on the localized specific absorption rate (SAR) has been analyzed for base station antennas. The analysis was conducted in order to determine whether localized SAR measurements of large multi-element base station antennas can be conducted using standardized procedures and commercially available equipment. More specifically, it was investigated if the antenna shifting measurement procedure, specified in the European base station exposure assessment standard EN 50383, will produce accurate localized SAR results for base station antennas larger than the specified measurement phantom. The obtained results show that SAR accuracy is affected by the presence of lossy material within distances of one wavelength from the tested antennas as a consequence of coupling and redistribution of transmitted power among the antenna elements. It was also found that the existing standardized phantom is not optimal for SAR measurements of large base station antennas. A new methodology is instead proposed based on a larger, box-shaped, whole-body phantom. Copyright © 2011 Wiley Periodicals, Inc.

Space station common module network topology and hardware development

Science.gov (United States)

Anderson, P.; Braunagel, L.; Chwirka, S.; Fishman, M.; Freeman, K.; Eason, D.; Landis, D.; Lech, L.; Martin, J.; Mccorkle, J.

1990-01-01

Conceptual space station common module power management and distribution (SSM/PMAD) network layouts and detailed network evaluations were developed. Individual pieces of hardware to be developed for the SSM/PMAD test bed were identified. A technology assessment was developed to identify pieces of equipment requiring development effort. Equipment lists were developed from the previously selected network schematics. Additionally, functional requirements for the network equipment as well as other requirements which affected the suitability of specific items for use on the Space Station Program were identified. Assembly requirements were derived based on the SSM/PMAD developed requirements and on the selected SSM/PMAD network concepts. Basic requirements and simplified design block diagrams are included. DC remote power controllers were successfully integrated into the DC Marshall Space Flight Center breadboard. Two DC remote power controller (RPC) boards experienced mechanical failure of UES 706 stud-mounted diodes during mechanical installation of the boards into the system. These broken diodes caused input to output shorting of the RPC's. The UES 706 diodes were replaced on these RPC's which eliminated the problem. The DC RPC's as existing in the present breadboard configuration do not provide ground fault protection because the RPC was designed to only switch the hot side current. If ground fault protection were to be implemented, it would be necessary to design the system so the RPC switched both the hot and the return sides of power.

Empirical model for mean temperature for Indian zone and estimation of precipitable water vapor from ground based GPS measurements

Directory of Open Access Journals (Sweden)

C. Suresh Raju

2007-10-01

Full Text Available Estimation of precipitable water (PW in the atmosphere from ground-based Global Positioning System (GPS essentially involves modeling the zenith hydrostatic delay (ZHD in terms of surface Pressure (P_s and subtracting it from the corresponding values of zenith tropospheric delay (ZTD to estimate the zenith wet (non-hydrostatic delay (ZWD. This further involves establishing an appropriate model connecting PW and ZWD, which in its simplest case assumed to be similar to that of ZHD. But when the temperature variations are large, for the accurate estimate of PW the variation of the proportionality constant connecting PW and ZWD is to be accounted. For this a water vapor weighted mean temperature (T_m has been defined by many investigations, which has to be modeled on a regional basis. For estimating PW over the Indian region from GPS data, a region specific model for T_m in terms of surface temperature (T_s is developed using the radiosonde measurements from eight India Meteorological Department (IMD stations spread over the sub-continent within a latitude range of 8.5°–32.6° N. Following a similar procedure T_m-based models are also evolved for each of these stations and the features of these site-specific models are compared with those of the region-specific model. Applicability of the region-specific and site-specific T_m-based models in retrieving PW from GPS data recorded at the IGS sites Bangalore and Hyderabad, is tested by comparing the retrieved values of PW with those estimated from the altitude profile of water vapor measured using radiosonde. The values of ZWD estimated at 00:00 UTC and 12:00 UTC are used to test the validity of the models by estimating the PW using the models and comparing it with those obtained from radiosonde data. The region specific T_m-based model is found to be in par with if not better than a

Ground Control Point - Wireless System Network for UAV-based environmental monitoring applications

Science.gov (United States)

Mejia-Aguilar, Abraham

2016-04-01

In recent years, Unmanned Aerial Vehicles (UAV) have seen widespread civil applications including usage for survey and monitoring services in areas such as agriculture, construction and civil engineering, private surveillance and reconnaissance services and cultural heritage management. Most aerial monitoring services require the integration of information acquired during the flight (such as imagery) with ground-based information (such as GPS information or others) for improved ground truth validation. For example, to obtain an accurate 3D and Digital Elevation Model based on aerial imagery, it is necessary to include ground-based information of coordinate points, which are normally acquired with surveying methods based on Global Position Systems (GPS). However, GPS surveys are very time consuming and especially for longer time series of monitoring data repeated GPS surveys are necessary. In order to improve speed of data collection and integration, this work presents an autonomous system based on Waspmote technologies build on single nodes interlinked in a Wireless Sensor Network (WSN) star-topology for ground based information collection and later integration with surveying data obtained by UAV. Nodes are designed to be visible from the air, to resist extreme weather conditions with low-power consumption. Besides, nodes are equipped with GPS as well as Inertial Measurement Unit (IMU), accelerometer, temperature and soil moisture sensors and thus provide significant advantages in a broad range of applications for environmental monitoring. For our purpose, the WSN transmits the environmental data with 3G/GPRS to a database on a regular time basis. This project provides a detailed case study and implementation of a Ground Control Point System Network for UAV-based vegetation monitoring of dry mountain grassland in the Matsch valley, Italy.

A simple decay-spectroscopy station at CRIS-ISOLDE

Energy Technology Data Exchange (ETDEWEB)

Lynch, K.M., E-mail: kara.marie.lynch@cern.ch [KU Leuven, Instituut voor Kern, en Stralingsfysica, BE-3001 Leuven (Belgium); EP Department, CERN, CH-1211 Geneva 23 (Switzerland); Cocolios, T.E. [KU Leuven, Instituut voor Kern, en Stralingsfysica, BE-3001 Leuven (Belgium); School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Althubiti, N. [School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Farooq-Smith, G.J. [KU Leuven, Instituut voor Kern, en Stralingsfysica, BE-3001 Leuven (Belgium); School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Gins, W. [KU Leuven, Instituut voor Kern, en Stralingsfysica, BE-3001 Leuven (Belgium); Smith, A.J. [School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom)

2017-02-01

A new decay-spectroscopy station (DSS2.0) has been designed by the CRIS collaboration for use at the radioactive ion beam facility, ISOLDE. With the design optimised for both charged-particle and γ-ray detection, the DDS2.0 allows high-efficiency decay spectroscopy to be performed. The DSS2.0 complements the existing decay-spectroscopy system at the CRIS experiment, and together provide the ability to perform laser-assisted nuclear decay spectroscopy on both ground state and long-lived isomeric species. This paper describes the new decay-spectroscopy station and presents the characterisation studies that have recently been performed.

Assessment of MTI Water Temperature Retrievals with Ground Truth from the Comanche Peak Steam Electric Station Cooling Lake

International Nuclear Information System (INIS)

Kurzeja, R.J.

2002-01-01

Surface water temperatures calculated from Multispectral Thermal Imager (MTI) brightness temperatures and the robust retrieval algorithm, developed by the Los Alamos National Laboratory (LANL), are compared with ground truth measurements at the Squaw Creek reservoir at the Comanche Peak Steam Electric Station near Granbury Texas. Temperatures calculated for thirty-four images covering the period May 2000 to March 2002 are compared with water temperatures measured at 10 instrumented buoy locations supplied by the Savannah River Technology Center. The data set was used to examine the effect of image quality on temperature retrieval as well as to document any bias between the sensor chip arrays (SCA's). A portion of the data set was used to evaluate the influence of proximity to shoreline on the water temperature retrievals. This study found errors in daytime water temperature retrievals of 1.8 C for SCA 2 and 4.0 C for SCA 1. The errors in nighttime water temperature retrievals were 3.8 C for SCA 1. Water temperature retrievals for nighttime appear to be related to image quality with the largest positive bias for the highest quality images and the largest negative bias for the lowest quality images. The daytime data show no apparent relationship between water temperature retrieval error and image quality. The average temperature retrieval error near open water buoys was less than corresponding values for the near-shore buoys. After subtraction of the estimated error in the ground truth data, the water temperature retrieval error was 1.2 C for the open-water buoys compared to 1.8 C for the near-shore buoys. The open-water error is comparable to that found at Nauru

A novel technique for extracting clouds base height using ground based imaging

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E. Hirsch

2011-01-01

Full Text Available The height of a cloud in the atmospheric column is a key parameter in its characterization. Several remote sensing techniques (passive and active, either ground-based or on space-borne platforms and in-situ measurements are routinely used in order to estimate top and base heights of clouds. In this article we present a novel method that combines thermal imaging from the ground and sounded wind profile in order to derive the cloud base height. This method is independent of cloud types, making it efficient for both low boundary layer and high clouds. In addition, using thermal imaging ensures extraction of clouds' features during daytime as well as at nighttime. The proposed technique was validated by comparison to active sounding by ceilometers (which is a standard ground based method, to lifted condensation level (LCL calculations, and to MODIS products obtained from space. As all passive remote sensing techniques, the proposed method extracts only the height of the lowest cloud layer, thus upper cloud layers are not detected. Nevertheless, the information derived from this method can be complementary to space-borne cloud top measurements when deep-convective clouds are present. Unlike techniques such as LCL, this method is not limited to boundary layer clouds, and can extract the cloud base height at any level, as long as sufficient thermal contrast exists between the radiative temperatures of the cloud and its surrounding air parcel. Another advantage of the proposed method is its simplicity and modest power needs, making it particularly suitable for field measurements and deployment at remote locations. Our method can be further simplified for use with visible CCD or CMOS camera (although nighttime clouds will not be observed.

Preliminary Assessment of Radiofrequency Radiation Exposure Level, From Mobile Base Stations in Ajaokuta and Environs, Kogi State, Nigeria

International Nuclear Information System (INIS)

Ushie, P. O.; Nwankwo, U.J.V.; Osahun, O. D.; Ayinmode, B.

2013-01-01

We present the result of a preliminary assessment of radio-frequency radiation exposure from selected mobile base stations in Ajaokuta environs using radio frequency (RF) meter (electromoge meter). The Power density of RF radiation within a radial distance of 125m was measured. Although values fluctuated due to the influence of unavoidable factors suspected to be interferences from other electromagnetic sources around reference base stations, we show from analysis that radiation exposure level is far below the standard limit (10W/cm 2 or 10 7 μW/m 2 ) set by the International Commission on Non-ionizing Radiation Protection (ICNIRP) regulatory agencies. The assessment was done in about ten (10) base stations in Ajaokuta, Kogi state. The position and elevation of the base stations were noted using a global positioning system (GPS) to ascertain the position of such stations on the world map. It was discovered that the limit of exposure to radio frequency radiation set by International Commission on Non-ionizing, Radiation Protection (ICNIRP) of 900MHz band expressed in the same unit as 10W/cm 2 or 10 7 μW/m 2 was not exceeded, the values were also influenced by some inevitable factors. Positions of most of the stations are sited close to homes.

Investigation of Ground-Water Contamination at Solid Waste Management Unit 12, Naval Weapons Station Charleston, North Charleston, South Carolina

Science.gov (United States)

Vroblesky, Don A.; Casey, Clifton C.; Petkewich, Matthew D.; Lowery, Mark A.; Conlon, Kevin J.; Harrelson, Larry G.

2007-01-01

The U.S. Geological Survey and the Naval Facilities Engineering Command Southeast investigated natural and engineered remediation of chlorinated volatile organic compound ground-water contamination at Solid Waste Management Unit 12 at the Naval Weapons Station Charleston, North Charleston, South Carolina. The primary contaminants of interest are tetrachloroethene, 1,1,1-trichloroethane, trichloroethene, cis-1,2-dichloroethene, vinyl chloride, 1,1-dichloroethane, and 1,1-dichloroethene. In general, the hydrogeology of Solid Waste Management Unit 12 consists of a surficial aquifer, composed of sand to clayey sand, overlain by dense clay that extends from about land surface to a depth of about 8 to 10 feet and substantially limits local recharge. During some months in the summer, evapotranspiration and limited local recharge result in ground-water level depressions in the forested area near wells 12MW-12S and 12MW-17S, seasonally reflecting the effects of evapotranspiration. Changes in surface-water levels following Hurricane Gaston in 2004 resulted in a substantial change in the ground-water levels at the site that, in turn, may have caused lateral shifting of the contaminant plume. Hydraulic conductivity, determined by slug tests, is higher along the axis of the plume in the downgradient part of the forests than adjacent to the plume, implying that there is some degree of lithologic control on the plume location. Hydraulic conductivity, hydraulic gradient, sulfur-hexafluoride measurements, and historical data indicate that ground-water flow rates are substantially slower in the forested area relative to upgradient areas. The ground-water contamination, consisting of chlorinated volatile organic compounds, extends eastward in the surficial aquifer from the probable source area near a former underground storage tank. Engineered remediation approaches include a permeable reactive barrier and phytoremediation. The central part of the permeable reactive barrier along the

Chilean Antarctic Stations on King George Island

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Katsutada Kaminuma

2000-07-01

Full Text Available The purpose of my visit to Chilean Antarctic Stations was to assess the present status of geophysical observations and research, as the South Shetland Island, West Antarctica, where the stations are located, are one of the most active tectonic regions on the Antarctic plate. The Instituto Antartico Chileno (INACH kindly gave me a chance to stay in Frei/Escudero Bases as an exchange scientist under the Antarctic Treaty for two weeks in January 2000. I stayed in Frei Base as a member of a geological survey group named "Tectonic Evolution of the Antarctic Peninsula" which was organized by Prof. F. Herve, University of Chile, from January 05 to 19,2000. All my activity in the Antarctic was organized by INACH. During my stay in Frei Base, I also visited Bellingshausen (Russian, Great Wall (China and Artigas (Uruguay stations. All these stations are located within walking distance of Frei Base. King Sejong Station (Korea, located 10km east from Frei Base, and Jubany Base (Argentine, another 6km south-east from King Sejong Station, were also visited with the aid of a zodiac boat that was kindly operated for us by King Sejong Station. All stations except Escudero Base carry out meteorological observations. The seismological observations in Frei Base are operated by Washington State University of the U. S. monitoring of earthquake activity and three-component geomagnetic observations are done at King Sejong and Great Wall stations. Earth tide is monitored at Artigas Base. Continuous monitoring of GPS and gravity change are planned at King Sejong Station in the near future. Scientific research activities of each country in the area in the 1999/2000 Antarctic summer season were studied and the logistic ability of all stations was also assessed for our future international cooperation.