Science.gov

Sample records for active radar spear

  1. SPEAR: Scalable Panels for Efficient, Affordable Radar

    DTIC Science & Technology

    2005-06-14

    folding Prime power and cooling becomes excessive 5 Example of Deployable Structure Transportation Mode Unfolded Aperture Air-Supported Radome for Wind...Deployable Structure Risks • Transportable, Lightweight, Deployable Structure • Alignment and Calibration of Deployed Structure • Wind Loading of Large...USASMDC / GTRI Array Implementation SPEAR Technical Director GTRI Industry Partners Radar System Technology (RST) Army, Navy, Air Force Missile Defense

  2. Bioactive compounds, antioxidant and binding activities and spear yield of Asparagus officinalis L.

    PubMed

    Lee, Jong Won; Lee, Jeong Hyun; Yu, In Ho; Gorinstein, Shela; Bae, Jong Hyang; Ku, Yang Gyu

    2014-06-01

    The aim of this investigation was to find a proper harvesting period and establishing fern number, which effects the spear yield, bioactive compounds and antioxidant activities of Asparagus officinalis L. Spears were harvested at 2, 4, and 6 weeks after sprouting. Control for comparison was used without harvest. Spears and total yield increased with prolonged spear harvest period. In harvest of 6 weeks long optimum spear yield was the highest and fern numbers were 5 ~ 8. Bioactive compounds (polyphenols, flavonoids, flavanols, tannins and ascorbic acid) and the levels of antioxidant activities by ferric-reducing/antioxidant power (FRAP) and cupric reducing antioxidant capacity (CUPRAC) assays in asparagus ethanol extracts significantly differed in the investigated samples and were the highest at 6 weeks harvest period (P < 0.05). The first and the second segments from the tip significantly increased with the increase of catalase (CAT). It was interesting to investigate in vitro how human serum albumin (HSA) interacts with polyphenols extracted from investigated vegetables. Therefore the functional properties of asparagus were studied by the interaction of polyphenol ethanol extracts with HSA, using 3D- FL. In conclusion, antioxidant status (bioactive compounds, binding and antioxidant activities) improved with the harvesting period and the first segment from spear tip. Appropriate harvesting is effective for higher asparagus yield and its bioactivity.

  3. Changes in phenylalanine ammonia-lyase activity and gene expression during storage of asparagus spears.

    PubMed

    Bhowmik, Pankaj K; Matsui, Toshiyuki

    2005-01-01

    A cDNA clone coding phenylalanine ammonia-lyase (PAL) was isolated from a cDNA library prepared from asparagus spears (Asparagus officinalis L. cv. Welcome) using the reverse transcription-polymerase chain reaction (RT-PCR). The partial cDNA clone encoded an mRNA of 527 bp and the derived amino acid sequence was found highly homologous to PAL from rice, maize and barley. Northern blot analysis showed an increase of pAS-PAL mRNA until 24 h at 20 degrees C, which coincided well with PAL activity and fiber development, suggesting that the increase is a response to the wounding associated with harvest.

  4. SPEAR3 Accelerator Physics Update

    SciTech Connect

    Safranek, James A.; Corbett, W.Jeff; Gierman, S.; Hettel, R.O.; Huang, X.; Nosochkov, Yuri; Sebek, Jim; Terebilo, Andrei; /SLAC

    2007-11-02

    The SPEAR3 storage ring at Stanford Synchrotron Radiation Laboratory has been delivering photon beams for three years. We will give an overview of recent and ongoing accelerator physics activities, including 500 mA fills, work toward top-off injection, long-term orbit stability characterization and improvement, fast orbit feedback, new chicane optics, low alpha optics & short bunches, low emittance optics, and MATLAB software. The accelerator physics group has a strong program to characterize and improve SPEAR3 performance

  5. Power Thresholds of SPEAR-induced Irregularities at Very High Latitudes

    NASA Astrophysics Data System (ADS)

    Wright, D. M.; Yeoman, T. K.; Robinson, T. R.; Thomas, E. C.; Baddeley, L. J.; Dhillon, R. S.

    2007-05-01

    SPEAR (Space Plasma Exploration by Active Radar) is a high power facility uniquely located to study the plasma physics and geophysics of the very high latitude magnetosphere and ionosphere. Recently, experiments have been undertaken to investigate the power thresholds required to excite field-aligned irregularities (FAIs). The artificially stimulated FAI act as intense targets in the fields of view of the CUTLASS HF coherent radar pair. Data derived using this artificial backscatter technique demonstrate that SPEAR effective radiated powers (ERPs) of the order of 1 MW or less are capable of initiating the formation of the FAI. This represents only 1/30th of the heating capability of SPEAR. Ionospheric hysteresis was also observed to occur during the experiments. This relates to the nature of the instability which leads to their excitation.

  6. SPEAR 3 INJECTION KICKER

    SciTech Connect

    Armett, Donald W.

    2002-08-20

    The design of the SPEAR 3 injection kicker system is presented. This system will include three kicker magnets and their associated pulsers. The magnet design is based on the DELTA kicker magnets, which present a low RF impedance to the beam, and are relatively straight-forward to construct. The pulsers use cascaded IGBT stages that are based on the modulator pulsers developed by a SLAC/LLNL collaboration for the NLC. Design considerations and the results of prototype tests will be discussed.

  7. SPEAR3 Commissioning

    SciTech Connect

    Harkay, K.; Sajaev, V.; Boland, M.J.; Tan, Y.E.; Krinsky, S.; Podobedov, B.; Decking, W.; Ropert, A.; Byrd, J.M.; Robin, D.; Scarvie, T.; Steier, C.; Fedurin, M.G.; Jines, P.; Chang, H.-P.; Kuo, C.-C.; Tsai, H.-J.; Yoon, M.H.; Boge, M.; Allison, S.; Bellomo, P.; /SLAC, SSRL /SOLEIL, Saint-Aubin

    2005-05-09

    The successful commissioning of the new SPEAR3 light source at the Stanford Synchrotron Radiation Laboratory (SSRL) will be reviewed. Orbit control, beam-based alignment, and an orbit interlock were commissioned. Orbit motion was characterized as a function of frequency. The linear optics was corrected for ID focusing and coupling errors. The nonlinear optics were investigated with dynamic aperture measurements as a function of energy and tune.

  8. The spectral forms of the stimulated electromagnetic emission near the 3-rd electron gyroharmonic at the SPEAR heating facility

    NASA Astrophysics Data System (ADS)

    Yurik, Roman; Tereshchenko, Evgeny; Baddeley, Lisa

    The results of the stimulated electromagnetic emission (SEE) observations of the final heating campaign with the SPEAR (Space Plasma Exploration by Active Radar) heating facility are reported. The presented observations were carried out in November 2013 on the Spitsbergen archipelago. The SEE observations were undertaken using the Polar Geophysical Institute (PGI) HF-interferometer, situated about 30~km from SPEAR at the geophysical observatory in Barensburg. The HF interferometer was modified such that it was possible to measure the polarization parameters of the received signal. The observatory also contains additional diagnostic equipment, such as magnetometers and receiving station of the RTU PGI KSC RAS, which were also utilized during the campaign. As a result of the observations the spectral forms of steady-state stimulated electromagnetic emission were obtained when the SPEAR heating facility operate in the frequency range from 4.14 MHz to 4.26 MHz (about 0.1 off the electron gyro frequency) under the day-time conditions. Lisa Baddeley’s research is supported by the Research Council of Norway/CoE under contract 223252/F50. SPEAR is supported by the Norwegian Research Council (grant 191628). The authors acknowledge Russian Foundation for Basic Research (Grant No. 13-05-12005-OFI-M) for financial support and participants of the heating campaign.

  9. SPEAR results, 1981

    SciTech Connect

    Scharre, D.L.

    1981-09-01

    New results from SPEAR on the inclusive photon spectrum at the psi' and on J/psi radiative transitions are presented. Evidence for an eta/sub c/' candidate is observed in the psi' inclusive photon spectrum at a mass M = 3592 +- 5 MeV. A new resonance, the theta(1640) which is observed to decay into eta eta, has been seen in radiative transitions from the J/psi. The spin-parity of the l(1440), previously observed in J/psi radiative transitions and originally identified as the E(1420), has been determined to be 0/sup -/.

  10. Meteor Beliefs Project: Spears of GodSpears of God

    NASA Astrophysics Data System (ADS)

    Hendrix, Howard V.; McBeath, Alastair; Gheorghe, Andrei Dorian

    2012-04-01

    A selection of genuine or supposedly sky-fallen objects from real-world sources, a mixture of weapons, tools and "magical" objects of heavenly provenance, are drawn from their re-use in the near-future science-fiction novel Spears of God by author Howard V Hendrix, with additional discussion. The book includes other meteoric and meteoritic items too, some of which have been the subject of previous Meteor Beliefs Project examinations.

  11. The SPEAR 3 Light Source

    SciTech Connect

    Corbett, W

    2003-10-03

    SPEAR 3 is an upgrade of the 18-cell SPEAR 2 storage ring to 3GeV beam energy, 18nm-radian emittance and up to 500mA circulating current. The existing arrangement of photon beam lines remains largely unchanged, but opportunities arise for additional ID and dipole radiation exit ports. For optimum beam stability, the entire tunnel floor will be excavated and replaced with reinforced concrete. The magnet/vacuum-chamber supports will be mounted on rigid steel rafts (3 per cell). The cable plant and RF drive will be installed ahead of time while the power supplies, tunnel floor and pre-assembled rafts will be installed in a 6-month shutdown beginning April, 2003.

  12. Active membrane phased array radar

    NASA Technical Reports Server (NTRS)

    Moussessian, Alina; Del Castillo, Linda; Huang, John; Sadowy, Greg; Hoffman, James; Smith, Phil; Hatake, Toshiro; Derksen, Chuck; Lopez, Bernardo; Caro, Ed

    2005-01-01

    We have developed the first membrane-based active phased array in L-band (1.26GHz). The array uses membrane compatible Transmit/Receive (T/R) modules (membrane T/R) for each antenna element. We use phase shifters within each T/R module for electronic beam steering. We will discuss the T/R module design and integration with the membrane, We will also present transmit and receive beam-steering results for the array.

  13. Supplier Performance Evaluation and Rating System (SPEARS)

    SciTech Connect

    Oged, M.; Warner, D.; Gurbuz, E.

    1993-03-01

    The SSCL Magnet Quality Assurance Department has implemented a Supplier Performance Evaluation and Rating System (SPEARS) to assess supplier performance throughout the development and production stages of the SSCL program. The main objectives of SPEARS are to promote teamwork and recognize performance. This paper examines the current implementation of SPEARS. MSD QA supports the development and production of SSCsuperconducting magnets while implementing the requirements of DOE Order 5700.6C. The MSD QA program is based on the concept of continuous improvement in quality and productivity. The QA program requires that procurement of items and services be controlled to assure conformance to specification. SPEARS has been implemented to meet DOE requirements and to enhance overall confidence in supplier performance. Key elements of SPEARS include supplier evaluation and selection as well as evaluation of furnished quality through source inspection, audit, and receipt inspection. These elements are described in this paper.

  14. The SPEAR 3 Diagnostic Beamlines

    SciTech Connect

    Corbett, W.J.; Limborg-Deprey, C.; Mok, W.Y.; Ringwall, A.; /SLAC

    2006-03-14

    SPEAR 3 has two diagnostic beam lines: an x-ray pinhole camera and a visible/UV laboratory. The pinhole camera images {approx}8 keV dipole radiation on a phosphor screen with a remote computer to capture digital images and a parallel video signal to the control room. The visible/UV beam line features an 8 mm high GlidCop ''cold finger'' to remove the x-ray core of the beam. The remaining light is deflected horizontally onto an optical bench where it is focused via reflective (Cassegrain) or refractive optics. The visible beam can be split into branch lines for a variety of experimental applications. This paper describes the experimental set up and projected use of both systems.

  15. SPEAR 3: the First Year of Operation

    SciTech Connect

    Hettel, R.O.; /SLAC

    2006-02-10

    The first electrons were accumulated in the newly completed 3-GeV SPEAR 3 storage ring on December 15, 2003, five days after the beginning of commissioning. By mid-January of 2004, 100 mA were stored, the maximum current allowed in the first phase of SPEAR 3 operation, and ring characterization and tuning continued until early March when the first photon beam line was opened for users. After the first year of operation the SPEAR 3 beam properties and ring performance had been extensively measured. These include micron stability using slow orbit feedback, an emittance coupling of {approx}0.1% and 50-h lifetimes. The performance of SPEAR 3 during its first year of commissioning and operation and the improvement plans are described.

  16. Development of Radar Control system for Multi-mode Active Phased Array Radar for atmospheric probing

    NASA Astrophysics Data System (ADS)

    Yasodha, Polisetti; Jayaraman, Achuthan; Thriveni, A.

    2016-07-01

    Modern multi-mode active phased array radars require highly efficient radar control system for hassle free real time radar operation. The requirement comes due to the distributed architecture of the active phased array radar, where each antenna element in the array is connected to a dedicated Transmit-Receive (TR) module. Controlling the TR modules, which are generally few hundreds in number, and functioning them in synchronisation, is a huge task during real time radar operation and should be handled with utmost care. Indian MST Radar, located at NARL, Gadanki, which is established during early 90's, as an outcome of the middle atmospheric program, is a remote sensing instrument for probing the atmosphere. This radar has a semi-active array, consisting of 1024 antenna elements, with limited beam steering, possible only along the principle planes. To overcome the limitations and difficulties, the radar is being augmented into fully active phased array, to accomplish beam agility and multi-mode operations. Each antenna element is excited with a dedicated 1 kW TR module, located in the field and enables to position the radar beam within 20° conical volume. A multi-channel receiver makes the radar to operate in various modes like Doppler Beam Swinging (DBS), Spaced Antenna (SA), Frequency Domain Interferometry (FDI) etc. Present work describes the real-time radar control (RC) system for the above described active phased array radar. The radar control system consists of a Spartan 6 FPGA based Timing and Control Signal Generator (TCSG), and a computer containing the software for controlling all the subsystems of the radar during real-time radar operation and also for calibrating the radar. The main function of the TCSG is to generate the control and timing waveforms required for various subsystems of the radar. Important components of the RC system software are (i) TR module configuring software which does programming, controlling and health parameter monitoring of the

  17. Mark III results from SPEAR

    SciTech Connect

    Toki, W.

    1983-11-01

    First results from the MARK III detector at SPEAR are presented based on 2.7 million J/psi decays. The eta/sub c/ is observed in three modes, J/psi ..-->.. ..gamma..eta/sub c/, (eta/sub c/ ..-->.. rho anti rho, eta..pi../sup +/..pi../sup -/, and phi phi). Using the phi phi mode, the eta/sub c/ spin-parity is determined to be 0/sup -/. The known radiative J/psi decays J/psi ..-->.. ..gamma..f(f ..-->.. ..pi../sup +/..pi../sup -/), ..gamma..eta'(eta' ..-->.. ..gamma..rho/sup 0/, eta..pi../sup +/..pi../sup -/), ..gamma..f'(f' ..-->.. kappa/sup +/kappa/sup -/), ..gamma..theta(theta ..-->.. kappa anti kappa), and ..gamma..iota(iota ..-->.. ..pi..kappa anti kappa) are observed and their branching ratios found to be in agreement with previous measurements. In the J/psi ..-->.. ..gamma..kappa/sup +/kappa/sup -/ mode a new state is observed at 2.22 GeV and in the J/psi ..-->.. ..gamma gamma..rho/sup 0/ and ..gamma..eta..pi../sup +/..pi../sup -/ modes evidence for new structures near 1.4 GeV is presented. 29 references.

  18. Study of ultra-low emittance design for SPEAR3

    SciTech Connect

    Wang, M. -H.; Huang, X.; Safranek, J.; /SLAC

    2015-09-17

    Since its 2003 construction, the SPEAR3 synchrotron light source at SLAC has continuously improved its performance by raising beam current, top-off injection, and smaller emittance. This makes SPEAR3 one of the most productive light sources in the world. Now, to further enhance the performance of SPEAR3, we are looking into the possibility of converting SPEAR3 to an ultra-low emittance storage ring within its site constraint.

  19. A new polarimetric active radar calibrator and calibration technique

    NASA Astrophysics Data System (ADS)

    Tang, Jianguo; Xu, Xiaojian

    2015-10-01

    Polarimetric active radar calibrator (PARC) is one of the most important calibrators with high radar cross section (RCS) for polarimetry measurement. In this paper, a new double-antenna polarimetric active radar calibrator (DPARC) is proposed, which consists of two rotatable antennas with wideband electromagnetic polarization filters (EMPF) to achieve lower cross-polarization for transmission and reception. With two antennas which are rotatable around the radar line of sight (LOS), the DPARC provides a variety of standard polarimetric scattering matrices (PSM) through the rotation combination of receiving and transmitting polarization, which are useful for polarimatric calibration in different applications. In addition, a technique based on Fourier analysis is proposed for calibration processing. Numerical simulation results are presented to demonstrate the superior performance of the proposed DPARC and processing technique.

  20. Doppler radar fall activity detection using the wavelet transform.

    PubMed

    Su, Bo Yu; Ho, K C; Rantz, Marilyn J; Skubic, Marjorie

    2015-03-01

    We propose in this paper the use of Wavelet transform (WT) to detect human falls using a ceiling mounted Doppler range control radar. The radar senses any motions from falls as well as nonfalls due to the Doppler effect. The WT is very effective in distinguishing the falls from other activities, making it a promising technique for radar fall detection in nonobtrusive inhome elder care applications. The proposed radar fall detector consists of two stages. The prescreen stage uses the coefficients of wavelet decomposition at a given scale to identify the time locations in which fall activities may have occurred. The classification stage extracts the time-frequency content from the wavelet coefficients at many scales to form a feature vector for fall versus nonfall classification. The selection of different wavelet functions is examined to achieve better performance. Experimental results using the data from the laboratory and real inhome environments validate the promising and robust performance of the proposed detector.

  1. Urban area navigation using active millimeter-wave radar

    NASA Astrophysics Data System (ADS)

    Corken, Richard A.; Evans, Michael A.

    2002-08-01

    An active MilliMeter Wave (MMW) system exploiting forward squinting Synthetic Aperture Radar (SAR) techniques can provide high resolution imagery. Such a radar offers a compact, all weather, day/night solution to the problem of accurate airborne navigation. Interpreting radar imagery of very cluttered urban areas is challenging, thus complicating autonomous navigation within such areas. For example, imagery is subject to effects such as layover distortions due to the height of buildings and also considerable radar shadowing. In this paper we examine the use of synthetic imagery to capture the key elements of the radar imagery. The MMW imagery can then be related to the physical models from which the synthetic imagery is generated leading to improved scene understanding. This paper describes the modeling process adopted and compares real imagery from a 35GHz forward squinting SAR radar with the synthetically generated imagery. The modeling process includes provision for terrain undulation, man-made and natural clutter regions and the ability to generate a sequence of imagery from a specified flight path. Examples presented include a representative urban area containing a variety of building structures. An important part of this research is the required fidelity of the synthetic scene model and therefore investigations into the level of detail required are also presented. Further work aims to exploit the synthetic imagery for navigational purposes through registration with the actual radar image thereby automatically locating key building structures with the imagery.

  2. Radiation Safety Considerations for Design of the SPEAR3 Storage Ring

    SciTech Connect

    Rokni, Sayed H.

    2003-03-17

    The SPEAR3 storage ring at the Stanford Synchrotron Radiation Laboratory (SSRL) is an upgrade of the existing SPEAR2 ring to a 3rd-generation storage ring with beam parameters of 3 GeV of electron beam energy, 18 nm-radian emittance and up to 500 mA of circulating current. While the existing injector will not be changed, the 234-m-circumference SPEAR2 ring components will be completely replaced with new components including C-shaped dipoles. The concrete shielding walls are to remain unchanged. This restriction, when considered in conjunction with the significant increase in the current and loss of self-shielding in the dipole magnets, requires careful study of the SPEAR3 shielding. This paper describes the methodology used for calculating the required shielding in a generic method. The criteria used for the design of shielding and beam loss estimates for various modes of beam operation are also presented. FLUKA Monte Carlo code was used extensively in generating source term data (dose rate as a function of angle for photons and neutrons) for both thin and thick targets. Attenuation profiles of neutrons and photons in concrete and lead shield materials are also presented. These data are being used to evaluate the shielding requirements for the lateral and ratchet walls. The current status of this approach will be discussed. Other issues presented include the use of active devices that are part of the radiation safety systems for the SPEAR3.

  3. Current radar responsive tag development activities at Sandia National Laboratories.

    SciTech Connect

    Plummer, Kenneth W.; Ormesher, Richard C.

    2003-09-01

    Over the past ten years, Sandia has developed RF radar responsive tag systems and supporting technologies for various government agencies and industry partners. RF tags can function as RF transmitters or radar transponders that enable tagging, tracking, and location determination functions. Expertise in tag architecture, microwave and radar design, signal analysis and processing techniques, digital design, modeling and simulation, and testing have been directly applicable to these tag programs. In general, the radar responsive tag designs have emphasized low power, small package size, and the ability to be detected by the radar at long ranges. Recently, there has been an interest in using radar responsive tags for Blue Force tracking and Combat ID (CID). The main reason for this interest is to allow airborne surveillance radars to easily distinguish U.S. assets from those of opposing forces. A Blue Force tracking capability would add materially to situational awareness. Combat ID is also an issue, as evidenced by the fact that approximately one-quarter of all U.S. casualties in the Gulf War took the form of ground troops killed by friendly fire. Because the evolution of warfare in the intervening decade has made asymmetric warfare the norm rather than the exception, swarming engagements in which U.S. forces will be freely intermixed with opposing forces is a situation that must be anticipated. Increasing utilization of precision munitions can be expected to drive fires progressively closer to engaged allied troops at times when visual de-confliction is not an option. In view of these trends, it becomes increasingly important that U.S. ground forces have a widely proliferated all-weather radar responsive tag that communicates to all-weather surveillance. The purpose of this paper is to provide an overview of the recent, current, and future radar responsive research and development activities at Sandia National Laboratories that support both the Blue Force Tracking

  4. To Spear or Not to Spear: Comparison of Saliva Collection Methods

    PubMed Central

    Talge, Nicole M.; Smith, Tiffany L.; Gunnar, Megan R.

    2008-01-01

    The eye spear, or an absorbent sponge-like material, has been proposed as a useful method of obtaining repeated saliva samples from infants and young children for cortisol determination. This brief report examines possible interference effects of different types of eye spears under conditions of relatively high and low cortisol levels, with or without the use of oral stimulant, and using two common assays. In Study 1, one type of eye spear was compared to passively collected drool using two different assays (EIA, DELFIA), across high and low concentrations of cortisol. No differences were found between methods for either assay or cortisol level, indicating that the spears are potentially a viable method of collecting saliva. Study 2 compared three other types of absorbent eye spears to passive drooling under the presence or absence of oral stimulant use. This study revealed that the degree of interference varied as a function of the specific type of eye spear that was employed; stimulant use had no effect. Taken together, the results raise important considerations to take into account when selecting collection materials and procedures in the measurement of salivary cortisol. PMID:18767029

  5. They Throw Spears: Reconciliation through Music

    ERIC Educational Resources Information Center

    Moore, Jane

    2013-01-01

    "They throw Spears" was written as part of the research for my PhD at the University of Sydney. The study was conducted in two primary schools: one in a remote area in the Northern Territory (NT) and one in an urban setting in Tasmania. It was conducted in 2009 and investigated Indigenous and non-Indigenous student, non-Indigenous…

  6. MU radar observation of the strong activity of 2006 Quadrantids

    NASA Astrophysics Data System (ADS)

    Abe, S.; Nakamura, T.; Watanabe, J.-I.; Tsutsumi, M.; Fujiwara, Y.; Ueda, M.; Yamamoto, M.-Y.; Mukai, T.

    Prominent activity of the 2006 Quadrantid meteor shower was observed from 18h through 21h UT on January 3 in Japan We carried out using a MU radar located in Shigaraki Japan which is a Mesosphere Stratosphere and Troposphere radar with a frequency and a peak power of 46 5 MHz and 1MW respectively The radar is consists of 475 Yagi antenna elements and the observation was performed in the meteor observation mode In order to calculate the ideal echo rate a response function which is the response of the radar system to a radiant in any position on the sky was considered Background activities were subtracted to estimate the Quadrantids activity with sufficient accuracy Velocity and echo height distribution were also derived Finally meteor radiant distribution RA 231 deg DEC 51 deg was calculated by using several thousands of echoes during Quadrantids activity A new system was installed to enhance the performance of the radar It consists of an Ultra Multi-channel Digital Receiving Subsystem and a Low-loss Signal Transfer Subsystem We will present the details of the 2006 Quadrantids characteristics by means of the new analysis method and the new system

  7. Ground motion improvements in SPEAR3

    NASA Astrophysics Data System (ADS)

    Safranek, James A.; Yan, Yiton T.; Dell'Orco, Domenico; Gassner, Georg; Sunilkumar, Nikita

    2016-09-01

    SPEAR3 is a third-generation synchrotron light source storage ring, about 234 meters in circumference. To meet the beam stability requirement, our goal is to ultimately achieve an orbit variation (relative to the photon beam lines) of less than 10% of the beam size, which is about 1 micron in the vertical plane. Hydrostatic leveling system (HLS) measurements show that the height of the SPEAR3 tunnel floor can vary by tens of microns daily without thermal insulation improvements. We present an analysis of the HLS data that shows that adding thermal insulation to the concrete walls of the storage ring tunnel dramatically decreased diurnal tunnel floor motion. Supported by US Department of Energy (DE-AC02-76SF00515) and the SULI program at SLAC National Laboratory

  8. Neandertal Humeri May Reflect Adaptation to Scraping Tasks, but Not Spear Thrusting

    PubMed Central

    Shaw, Colin N.; Hofmann, Cory L.; Petraglia, Michael D.; Stock, Jay T.; Gottschall, Jinger S.

    2012-01-01

    Unique compared with recent and prehistoric Homo sapiens, Neandertal humeri are characterised by a pronounced right-dominant bilateral strength asymmetry and an anteroposteriorly strengthened diaphyseal shape. Remodeling in response to asymmetric forces imposed during regular underhanded spear thrusting is the most influential explanatory hypothesis. The core tenet of the “Spear Thrusting Hypothesis”, that underhand thrusting requires greater muscle activity on the right side of the body compared to the left, remains untested. It is unclear whether alternative subsistence behaviours, such as hide processing, might better explain this morphology. To test this, electromyography was used to measure muscle activity at the primary movers of the humerus (pectoralis major (PM), anterior (AD) and posterior deltoid (PD)) during three distinct spear-thrusting tasks and four separate scraping tasks. Contrary to predictions, maximum muscle activity (MAX) and total muscle activity (TOT) were significantly higher (all values, p<.05) at the left (non-dominant) AD, PD and PM compared to the right side of the body during spear thrusting tasks. Thus, the muscle activity required during underhanded spearing tasks does not lend itself to explaining the pronounced right dominant strength asymmetry found in Neandertal humeri. In contrast, during the performance of all three unimanual scraping tasks, right side MAX and TOT were significantly greater at the AD (all values, p<.01) and PM (all values, p<.02) compared to the left. The consistency of the results provides evidence that scraping activities, such as hide preparation, may be a key behaviour in determining the unusual pattern of Neandertal arm morphology. Overall, these results yield important insight into the Neandertal behavioural repertoire that aided survival throughout Pleistocene Eurasia. PMID:22815742

  9. Neandertal humeri may reflect adaptation to scraping tasks, but not spear thrusting.

    PubMed

    Shaw, Colin N; Hofmann, Cory L; Petraglia, Michael D; Stock, Jay T; Gottschall, Jinger S

    2012-01-01

    Unique compared with recent and prehistoric Homo sapiens, Neandertal humeri are characterised by a pronounced right-dominant bilateral strength asymmetry and an anteroposteriorly strengthened diaphyseal shape. Remodeling in response to asymmetric forces imposed during regular underhanded spear thrusting is the most influential explanatory hypothesis. The core tenet of the "Spear Thrusting Hypothesis", that underhand thrusting requires greater muscle activity on the right side of the body compared to the left, remains untested. It is unclear whether alternative subsistence behaviours, such as hide processing, might better explain this morphology. To test this, electromyography was used to measure muscle activity at the primary movers of the humerus (pectoralis major (PM), anterior (AD) and posterior deltoid (PD)) during three distinct spear-thrusting tasks and four separate scraping tasks. Contrary to predictions, maximum muscle activity (MAX) and total muscle activity (TOT) were significantly higher (all values, p<.05) at the left (non-dominant) AD, PD and PM compared to the right side of the body during spear thrusting tasks. Thus, the muscle activity required during underhanded spearing tasks does not lend itself to explaining the pronounced right dominant strength asymmetry found in Neandertal humeri. In contrast, during the performance of all three unimanual scraping tasks, right side MAX and TOT were significantly greater at the AD (all values, p<.01) and PM (all values, p<.02) compared to the left. The consistency of the results provides evidence that scraping activities, such as hide preparation, may be a key behaviour in determining the unusual pattern of Neandertal arm morphology. Overall, these results yield important insight into the Neandertal behavioural repertoire that aided survival throughout Pleistocene Eurasia.

  10. Results of Dose Control and Measurement Plans Appliedfor SPEAR3 Commissioning Year (FY04)

    SciTech Connect

    Khater, Hesham; Liu, James; Prinz, Alyssa; Allan, Jim; Rokni, Sayed; /SLAC

    2007-02-12

    Dose control and measurement plans for the SPEAR3 Booster and storage ring have taken place during the SPEAR3 commissioning. The initial commissioning period (SPEAR3 start-up) covered the time period from the beginning of November 2003 to the early part of March 2004. The period from the beginning of March to the beginning of August 2004 has been mostly dedicated to the scientific program. The initial commissioning period was characterized with frequent injection and significantly higher losses. In comparison, the scientific program period was characterized with more stable beam operation with limited number of injections per day and lower beam losses. Three types of dose measurements, passive, active and special measurements, were implemented around the SPEAR3 Booster and storage ring. Based on the expected radiation hazards, several dose control measures were adopted at several stages of the commissioning. In the early stages of commissioning, areas within 4.5 m from the walls of the Booster and storage ring were designated as Radiation Areas (RA). Areas outside RA were classified as Radiologically Controlled Area (RCA). Access to these areas required less training than the radiation areas. A monthly review of the accelerator operation conditions and radiation measurement results were used to determine the changes needed for the RA classification status and associated dose control measures.

  11. Skew quad compensation for SPEAR minibeta optics

    SciTech Connect

    Wille, K.

    1984-06-01

    With the new minibeta insertion for SPEAR the betatron coupling and the perturbations of beam optics caused by the solenoid field of the MARK III detector can't be compensated by the simple coils used so far. Therefore another scheme with four skew quads arranged in two families has been chosen. Even though this scheme doesn't compensate the effect of the solenoid on the beam completely, the residual emittance coupling is much less than 1% which should be sufficient under all running conditions. The major advantage of this concept is its simplicity.

  12. Investigation of a monochromator scheme for SPEAR

    SciTech Connect

    Wille, K.; Chao, A.W.

    1984-08-01

    The possibility of mono-chromatizing SPEAR for the purpose of increasing the hadronic event rate at the narrow resonances was investigated. By using two pairs of electostatic skew quads in monochromator scheme it is found that the event rate can be increased by a factor of 2 for the mini beta optics assuming the luminosity is kept unchanged. An attempt to increase this enhancement factor by major rearrangements of the ring magnets has encountered serious optical difficulties; although enhancement factor of 8 seems possible in principle, this alternative is not recommended.

  13. SPEAR 3 Upgrade Project: A Status Report

    SciTech Connect

    Corbett, William

    2001-07-07

    The SPEAR 3 upgrade project at SSRL will replace the original FODO lattice with a 234-m, 18-cell DBA lattice with gradient dipoles. The new hardware draws heavily on PEP-II B-Factory technology: a copper vacuum chamber, IGBT power supply technology, and mode-damped rf cavities to reach beam currents up to 500 mA at 3 GeV. First article magnets, supports, girders, vacuum chambers, pumps and RF components have been fabricated and a prototype girder assembly is nearing completion. I&C systems, radiation shielding and utility upgrades are in progress. In this paper we report on the status of the main accelerator subsystems.

  14. Parasitic Cavities Losses in SPEAR-2

    SciTech Connect

    Sands, Matt

    2016-12-19

    In PEP the large number of particles in a bunch, together with the small bunch length, may cause grievous energy loss from the beam to parasitic modes in the accelerating cavities. I have recently tried to estimate the parasitic cavity in PEP, based on a paper of Keil and I have obtained the result that the loss to parasitic modes will be about 10 MeV per particle per revolution for a bunch length of about 10 cm. In this note, I bring together some of the considerations that might bear on an experimental investigation of the loss using SPEAR-2.

  15. Status of Digital Orbit Feedback for SPEAR

    SciTech Connect

    Hettel, Robert

    2003-05-30

    The present global orbit feedback system for SPEAR can adjust the electron beam position with a cycle time of 5 s. In addition, 50 Hz analog local servos stabilize the vertical photon beam position at monitors situated in the ten SSRL beamlines. The global and local systems will soon be merged into a single unified system operating from a dedicated DSP board. The goal is to acquire orbits, process the data, and correct beam position in a 1-2 ms interval to achieve a 30-50 Hz closed-loop bandwidth.

  16. Bunch Length Measurements in SPEAR3

    SciTech Connect

    Corbett, W.J.; Fisher, A.; Huang, X.; Safranek, J.; Sebek, J.; Lumpkin, A.; Sannibale, F.; Mok, W.; /Unlisted

    2007-11-28

    A series of bunch length measurements were made in SPEAR3 for two different machine optics. In the achromatic optics the bunch length increases from the low-current value of 16.6ps rms to about 30ps at 25ma/bunch yielding an inductive impedance of -0.17{Omega}. Reducing the momentum compaction factor by a factor of {approx}60 [1] yields a low-current bunch length of {approx}4ps rms. In this paper we review the experimental setup and results.

  17. Commissioning the SPEAR3 Diagnostic Beamlines

    SciTech Connect

    Corbett, W.J.; Limborg-Deprey, C.; Mok, W.Y.; Ringwall, A.; /SLAC

    2007-06-05

    SPEAR3 has two diagnostic beam lines: an x-ray pinhole camera and a visible/UV beam line. The pinhole camera images {approx}8 keV dipole synchrotron radiation (SR) incident on a phosphor screen. The visible beam line delivers conventional optical radiation to an array of cameras and diagnostic elements on a 1x3m optical bench. This paper briefly reviews the pinhole camera system while concentrating more on visible beam line power transmission calculations and streak camera data. Impedance estimates in the nominal optics and bunch length measurements in low-alpha optics are presented.

  18. Portable database driven control system for SPEAR

    SciTech Connect

    Howry, S.; Gromme, T.; King, A.; Sullenberger, M.

    1985-04-01

    The new computer control system software for SPEAR is presented as a transfer from the PEP system. Features of the target ring (SPEAR) such as symmetries, magnet groupings, etc., are all contained in a design file which is read by both people and computer. People use it as documentation; a program reads it to generate the database structure, which becomes the center of communication for all the software. Geometric information, such as element positions and lengths, and CAMAC I/O routing information is entered into the database as it is developed. Since application processes refer only to the database and since they do so only in generic terms, almost all of this software (representing more then fifteen man years) is transferred with few changes. Operator console menus (touchpanels) are also transferred with only superficial changes for the same reasons. The system is modular: the CAMAC I/O software is all in one process; the menu control software is a process; the ring optics model and the orbit model are separate processes, each of which runs concurrently with about 15 others in the multiprogramming environment of the VAX/VMS operating system. 10 refs., 1 fig.

  19. SPEAR3 Gradient Dipole Core Fabrication

    SciTech Connect

    Li, Nanyang

    2003-07-29

    Traditional means of core fabrication are to glue the laminations or weld them to form the yoke structure. These means result in good yoke assemblies for shorter (<0.6m) magnets. However, because of weld distortions or mechanical strength limitations, welding and/or gluing techniques are difficult to gain high mechanical precision for longer cores. The SPEAR3 gradient dipoles are up to 1.45m long and require distortions of <0.05mm. Therefore, the SPEAR3 gradient dipole core design incorporated an assembly technique, originally devised for the PEPII insertion quadrupoles and later adapted for the ALS gradient magnets. This technique involved fabricating a rigid frame for the core, precisely stacking and compressing the laminations using hydraulic jacks and granite surfaces and straight edges, and fixing the laminations in the frame by filling the grooves between the laminations and frame using steel loaded epoxy. Although this technique has been used in the past, it has never been fully described and published. This paper is written to provide a detailed description of the procedure and to present measurement data demonstrating the mechanical precision and stiffness of the resulting product.

  20. Periodogram Analysis on Solar Activities Based on El Campo Solar Radar Observation Data

    NASA Astrophysics Data System (ADS)

    Lin, Ye; Zhi-ning, Qu; Min, Wang; Guan-nan, Gao; Jun, Lin; Zhi-chun, Duan

    2016-10-01

    Solar radar can transmit radar waves toward the Sun actively at a specific waveband and receive the reflected waves. By analyzing the echoes, we can obtain the information of motion, magnetic field, and other properties of the solar atmosphere. The El Campo solar radar has done regular observations on the solar corona for 8 years from 1961 to 1969, to trace the variation of solar activities. We have made a periodicity analysis on the obtained data with the Lomb-Scargle periodogram algorithm, and found that there are the 200 day and 540 day periods existed in the variation of the measured solar radar cross section. In addition, we have selected the larger radar cross sections (≥ 20σ⊙) to compare with the Dst indexes. Finally, we have summarized the El Campo solar radar experiment and give a prospect for the future development of the solar radar observation.

  1. Beyond Historical Fiction: Speare's "The Witch of Blackbird Pond."

    ERIC Educational Resources Information Center

    Thuente, Mary Helen

    1985-01-01

    Reviews "The Witch of Blackbird Pond" by E. Speare to show how the full narrative power of the novel derives from the author's successful integration of two separate narrative genres: historical fiction and the folktale. (EL)

  2. Geosynchronous SAR Orbit Estimation Based on Active Radar Calibrators

    NASA Astrophysics Data System (ADS)

    Leanza, Antonio; Monti Guarnieri, Andrea; Boroquets Ibars, Antoni

    2016-08-01

    The Geosynchronous SAR (GEOSAR) is a system designed for continuous monitoring of a fixed region of the Earth. Differently from LEOSAR, the GEOSAR system requires very long times to form its Synthetic Aperture (SA). This entails the onset of several decorrelation sources, such as atmosphere propagation, orbit perturbations, clock drifts, that have to be compensated to avoid defocusing. In this paper, in particular, it is proposed a solution to cope with the phase error introduced by orbit perturbations within the SA by means of some Active Radar Calibrators (ARC) deployed at convenient positions in the illuminated area. Each ARC provides two-way pulse by pulse echo delay and carrier phase observations used to track the satellite position. The estimation follows an iterative approach whose steps are dividing the SA in sub-apertures, performing the estimation for each sub-aperture, applying the estimated orbit correction and repeating for longer sub-apertures.

  3. Active calibration target for bistatic radar cross-section measurements

    NASA Astrophysics Data System (ADS)

    Pienaar, M.; Odendaal, J. W.; Joubert, J.; Cilliers, J. E.; Smit, J. C.

    2016-05-01

    Either passive calibration targets are expensive and complex to manufacture or their bistatic radar cross section (RCS) levels are significantly lower than the monostatic RCS levels of targets such as spheres, dihedral, and trihedral corner reflectors. In this paper the performance of an active calibration target with relative high bistatic RCS values is illustrated as a reference target for bistatic RCS measurements. The reference target is simple to manufacture, operates over a wide frequency range, and can be configured to calibrate all four polarizations (VV, HH, HV, and VH). Bistatic RCS measurements of canonical targets, performed in a controlled environment, are calibrated with the reference target and the results are compared to simulated results using FEKO.

  4. Booster Synchrotron RF System Upgrade for SPEAR3

    SciTech Connect

    Park, Sanghyun; Corbett, Jeff; /SLAC

    2012-07-06

    Recent progress at the SPEAR3 includes the increase in stored current from 100 mA to 200 mA and top-off injection to allow beamlines to stay open during injection. Presently the booster injects 3.0 GeV beam to SPEAR3 three times a day. The stored beam decays to about 150 mA between the injections. The growing user demands are to increase the stored current to the design value of 500 mA, and to maintain it at a constant value within a percent or so. To achieve this goal the booster must inject once every few minutes. For improved injection efficiency, all RF systems at the linac, booster and SPEAR3 need to be phase-locked. The present booster RF system is basically a copy of the SPEAR2 RF system with 358.5 MHz and 40 kW peak RF power driving a 5-cell RF cavity for 1.0 MV gap voltage. These requirements entail a booster RF system upgrade to a scaled down version of the SPEAR3 RF system of 476.3 MHz with 1.2 MW cw klystron output power capabilities. We will analyze each subsystem option for their merits within budgetary and geometric space constraints. A substantial portion of the system will come from the decommissioned PEP-II RF stations.

  5. Study of ultra-low emittance design for Spear3 using longitudinal gradient dipole

    SciTech Connect

    Wang, M. -H.; Huang, X.; Safranek, J.

    2015-09-24

    Since its 2003 construction, the SPEAR3 synchrotron light source at SLAC has continuously improved its performance by raising beam current, top-off injection, and smaller emittance. This makes SPEAR3 one of the most productive light sources in the world. Now to further enhance the performance of SPEAR3, we are looking into the possibility of converting SPEAR3 to an ultra-low emittance storage ring within its site constraint.

  6. Polarimetric radar characteristics of storms with and without lightning activity

    NASA Astrophysics Data System (ADS)

    Mattos, Enrique V.; Machado, Luiz A. T.; Williams, Earle R.; Albrecht, Rachel I.

    2016-12-01

    This paper analyzes the cloud microphysics in different layers of storms as a function of three-dimensional total lightning density. A mobile X-band polarimetric radar and very high frequency (VHF) sources from Lightning Mapping Array (LMA) observations during the 2011/2012 Brazil spring-summer were used to determine the microphysical signatures of radar vertical profiles and lightning density. This study quantified the behavior of 5.3 million vertical profiles of the horizontal reflectivity (ZH), differential reflectivity (ZDR), specific differential phase (KDP), and correlation coefficient (ρHV). The principal changes in the polarimetric variables occurred only for VHF source rate density greater than 14 VHF sources per km2 in 4 min. These storms showed an enhanced positive KDP in the mixed 1 layer (from 0 to -15°C) probably associated with supercooled liquid water signatures, whereas regions with negative ZDR and KDP and moderate ZH in the mixed 2 layer (from -15 to -40°C) were possibly associated with the presence of conical graupel. The glaciated (above -40°C) and upper part of the mixed 2 layers showed a significant trend to negative KDP with an increase in lightning density, in agreement with vertical alignment of ice particle by the cloud electric field. A conceptual model that presents the microphysical signatures in storms with and without lightning activity was constructed. The observations documented in this study provide an understanding of how the combinations of polarimetric variables could help to identify storms with different lightning density and vice versa.

  7. The Incidence of Spearing during a High School's 1975 and 1990 Football Seasons.

    ERIC Educational Resources Information Center

    Heck, Jonathan F.

    1996-01-01

    Reports a study that examined the incidence of spearing between two high school football seasons, one before and one after a rule change banning spearing. Reviews of 18 game films of a New Jersey team from 1975 and 1990 indicated that, overall, the rule change did not have a favorable impact on the incidence of spearing. (SM)

  8. Radars in space

    NASA Technical Reports Server (NTRS)

    Delnore, Victor E.

    1990-01-01

    The capabilities of active microwave devices operating from space (typically, radar, scatterometers, interferometers, and altimeters) are discussed. General radar parameters and basic radar principles are explained. Applications of these parameters and principles are also explained. Trends in space radar technology, and where space radars and active microwave sensors in orbit are going are discussed.

  9. An Introduction to SPEAR (Seismogram Picking Error from Analyst Review)

    NASA Astrophysics Data System (ADS)

    Zeiler, C. P.; Velasco, A. A.; Anderson, D.; Pingitore, N. E.

    2008-12-01

    A grassroots initiative began in February of 2008 at the University of Texas at El Paso to understand how seismologists measure earthquakes. The Seismogram Picking Error from Analyst Review (SPEAR) project is designed to be a forum where seismologists can propose, discuss and experimentally test theories on proper procedures to identify and measure seismic phases. We outline the history of seismogram analysis and explore areas of seismogram analysis that still need to be defined. The main concern for SPEAR, at this time, is the impact of picking errors produced by merging earthquake catalogs. Our initial effort has been to establish a common data set for seismologists to pick. The preliminary studies from this data set have shown that significant bias between authors of catalogs may exist. We provide techniques to ensure that these biases can be identified and correctly managed to provide accurate mergers of earthquake measurements. The overall goal of SPEAR is to provide a repository of information to aid seismologists in comparing and sharing measurements. We want to document in the repository and explore all aspects of the picking process, from the basics of learning how to read a seismogram to complex transformations and enhancements of signals. Your participation in SPEAR will aid the seismological community to close the knowledge gaps that exist in seismogram analysis.

  10. Selected results from the Mark II at SPEAR

    SciTech Connect

    Scharre, D.L.

    1980-06-01

    Recent results on radiative transitions from the psi(3095), charmed meson decay, and the Cabibbo-suppressed decay tau ..-->.. K* ..nu../sub tau/ are reviewed. The results come primarily from the Mark II experiment at SPEAR, but preliminary results from the Crystal Ball experiment on psi radiative transitions are also discussed.

  11. Signs in Speare's "The Sign of the Beaver."

    ERIC Educational Resources Information Center

    Moseley, Ann

    1995-01-01

    Describes the use of signs in Elizabeth George Speare's "The Sign of the Beaver," in which a settler youth and a young Indian learn to communicate by signs, and how the signs reveal much about each character's culture. Summarizes the plot elements of the book, including characters who are not as sympathetic to the Indian point of view.…

  12. Observation of Beam ION Instability in Spear3

    SciTech Connect

    Teytelman, D.; Cai, Y.; Corbett, W.J.; Raubenheimer, T.O.; Safranek, J.A.; Schmerge, J.F.; Sebek, J.J.; Wang, L.; /SLAC

    2011-12-14

    Weak vertical coupled bunch instability with oscillation amplitude at {mu}m level has been observed in SPEAR3. The instability becomes stronger when there is a vacuum pressure rise by partially turning off vacuum pumps and it becomes weaker when the vertical beam emittance is increased by turning off the skew quadrupole magnets. These confirmed that the instability was driven by ions in the vacuum. The threshold of the beam ion instability when running with a single bunch train is just under 200 mA. This paper presents the comprehensive observations of the beam ion instability in SPEAR3. The effects of vacuum pressure, beam current, beam filling pattern, chromaticity, beam emittance and bunch-by-bunch feedback are investigated in great detail. In an electron accelerator, ions generated from the residual gas molecules can be trapped by the beam. Then these trapped ions interact resonantly with the beam and cause beam instability and emittance blow-up. Most existing light sources use a long single bunch train filling pattern, followed by a long gap to avoid multi-turn ion trapping. However, such a gap does not preclude ions from accumulating during one passage of the single bunch train beam, and those ions can still cause a Fast Ion Instability (FII) as predicted by Raubenheimer and Zimmermann. FII has been observed in ALS, and PLS by artificially increasing the vacuum pressure by injecting helium gas into the vacuum chamber or by turning off the ion pumps in order to observe the beam ion instability. In some existing rings, for instance B factory, the beam ion instability was observed at the beginning of the machine operation after a long period of shutdown and then it automatically disappeared when the vacuum was better. However, when the beam emittance becomes smaller, the FII can occur at nominal conditions as observed in PLS, SOLEIL and SSRF. This paper reports the observations of beam ion instabilities in SPEAR3 under different condition during a period of one

  13. The Soil Moisture Active/Passive (SMAP) Mission Radar: A Novel Conically Scanning SAR

    NASA Technical Reports Server (NTRS)

    Spencer, Michael; Chan, Samuel; Veilleux, Louise; Wheeler, Kevin

    2009-01-01

    The Soil Moisture Active/Passive (SMAP) mission is a NASA mission identified by the NRC "decadal survey" to measure both soil moisture and freeze/thaw state from space. The mission will use both active radar and passive radiometer instruments at L-Band. In order to achieve a wide swath at sufficiently high resolution for both active and passive chan-nels, an instrument architecture that uses a large rotating reflector is employed. The active radar will further utilize SAR processing in order to obtain the sub-footprint resolution necessary for the geophysical retrievals. The SMAP radar has a unique geometry where the antenna footprint is continuously rotated about nadir in a conical fashion, as opposed to the more common side-looking SAR design. In additional to the unconventional scan geometry, the SMAP radar must address the effects of Faraday rotation and radio frequency interference (RFI), both consequences of the L-Band frequency of operation.

  14. Analysis of Active Lava Flows on Kilauea Volcano, Hawaii, Using SIR-C Radar Correlation Measurements

    NASA Technical Reports Server (NTRS)

    Zebker, H. A.; Rosen, P.; Hensley, S.; Mouginis-Mark, P. J.

    1995-01-01

    Precise eruption rates of active pahoehoe lava flows on Kilauea volcano, Hawaii, have been determined using spaceborne radar data acquired by the Space Shuttle Imaging Radar-C (SIR-C). Measurement of the rate of lava flow advance, and the determination of the volume of new material erupted in a given period of time, are among the most important observations that can be made when studying a volcano.

  15. Resolutions of Problems that Occurred in SPEAR3 Magnet Production

    SciTech Connect

    Li, Nanyang

    2005-05-27

    Some problems occurred during the SPEAR3 magnet production at IHEP, China. It was very hard to find resolution from existing knowledge of those problems. It was possible that similar problems might have happen in building accelerator magnet in other institutes before, but they were not addressed in public papers. These problems were discussed and solved by engineers from both SLAC and IHEP after conducting certain experiments. Traditionally, the magnet design and measurement data have been always well documented and addressed in papers, but the production experiences have not been recorded adequately. It is the goal of this paper to record the problems and their resolutions during SPEAR3 magnet production at IHEP China, which will certainly benefit future magnet projects.

  16. The SPEAR Instrument and On-Orbit Performance

    NASA Astrophysics Data System (ADS)

    Edelstein, J.; Korpela, E. J.; Adolfo, J.; Bowen, M.; Feuerstein, M.; Hull, J.; Jelinsky, S.; Nishikida, K.; McKee, K.; Berg, P.; Chung, R.; Fischer, J.; Min, K.-W.; Oh, S.-H.; Rhee, J.-G.; Ryu, K.; Shinn, J.-H.; Han, W.; Jin, H.; Lee, D.-H.; Nam, U.-W.; Park, J.-H.; Seon, K.-I.; Yuk, I.-S.

    2006-06-01

    The SPEAR (or ``FIMS'') instrumentation has been used to conduct the first large-scale spectral mapping of diffuse cosmic far-ultraviolet (FUV; 900-1750 Å) emission, including important diagnostics of interstellar hot (104-106 K) and photoionized plasmas, H2, and dust-scattered starlight. The instrumentation's performance has allowed for the unprecedented detection of astrophysical diffuse FUV emission lines. A spectral resolution of λ/Δλ~550 and an imaging resolution of 5' is achieved on-orbit in the Short (900-1150 Å) and Long (1350-1750 Å) bandpass channels within their respective 4.0d×4.6 arcmin and 7.4d×4.3 arcmin fields of view. We describe the SPEAR imaging spectrographs, their performance, and the nature and handling of their data.

  17. Characterization of Slow Orbit Motion in the SPEAR3

    SciTech Connect

    Sunilkumar, Nikita; Gassner, Georg; Safranek, James; Yan, Yiton; /SLAC

    2012-07-09

    SPEAR3 is a third-generation synchrotron light source storage ring. The beam stability requirements are {approx}10% of the beam size, which is about 1 micron in the vertical plane. Hydrostatic level system (HLS) measurements show that the height of the SPEAR3 tunnel floor varies by tens of microns daily. We present analysis of the HLS data, including accounting for common-mode tidal motion. We discuss the results of experiments done to determine the primary driving source of ground motion. We painted the accelerator tunnel walls white; we temporarily installed Mylar over the asphalt in the center of the accelerator; and we put Mylar over a section of the tunnel walls.

  18. Monte Carlo simulation of the spear reflectometer at LANSCE

    SciTech Connect

    Smith, G.S.

    1995-12-31

    The Monte Carlo instrument simulation code, MCLIB, contains elements to represent several components found in neutron spectrometers including slits, choppers, detectors, sources and various samples. Using these elements to represent the components of a neutron scattering instrument, one can simulate, for example, an inelastic spectrometer, a small angle scattering machine, or a reflectometer. In order to benchmark the code, we chose to compare simulated data from the MCLIB code with an actual experiment performed on the SPEAR reflectometer at LANSCE. This was done by first fitting an actual SPEAR data set to obtain the model scattering-length-density profile, {Beta}(z), for the sample and the substrate. Then these parameters were used as input values for the sample scattering function. A simplified model of SPEAR was chosen which contained all of the essential components of the instrument. A code containing the MCLIB subroutines was then written to simulate this simplified instrument. The resulting data was then fit and compared to the actual data set in terms of the statistics, resolution and accuracy.

  19. Validation of a microwave radar system for the monitoring of locomotor activity in mice

    PubMed Central

    Pasquali, Vittorio; Scannapieco, Eugenio; Renzi, Paolo

    2006-01-01

    Background The general or spontaneous motor activity of animals is a useful parameter in chronobiology. Modified motion detectors can be used to monitor locomotor activity rhythms. We modified a commercial microwave-based detection device and validated the device by recording circadian and ultradian rhythms. Methods Movements were detected by microwave radar based on the Doppler effect. The equipment was designed to detect and record simultaneously 12 animals in separate cages. Radars were positioned at the bottom of aluminium bulkheads. Animal cages were positioned above the bulkheads. The radars were connected to a computer through a digital I/O board. Results The apparatus was evaluated by several tests. The first test showed the ability of the apparatus to detect the exact frequency of the standard moving object. The second test demonstrated the stability over time of the sensitivity of the radars. The third was performed by simultaneous observations of video-recording of a mouse and radar signals. We found that the radars are particularly sensitive to activities that involve a displacement of the whole body, as compared to movement of only a part of the body. In the fourth test, we recorded the locomotor activity of Balb/c mice. The results were in agreement with published studies. Conclusion Radar detectors can provide automatic monitoring of an animal's locomotor activity in its home cage without perturbing the pattern of its normal behaviour or initiating the spurt of exploration occasioned by transfer to a novel environment. Recording inside breeding cages enables long-term studies with uninterrupted monitoring. The use of electromagnetic waves allows contactless detection and freedom from interference of external stimuli. PMID:16674816

  20. Structural and Sensory Characterization of Bitter Tasting Steroidal Saponins from Asparagus Spears (Asparagus officinalis L.).

    PubMed

    Dawid, Corinna; Hofmann, Thomas

    2012-12-05

    Application of sequential solvent extraction and iterative chromatographic separation in combination with taste dilution analysis recently revealed a series of steroidal saponins as the key contributors to the typical bitter taste of white asparagus spears (Asparagus officinalis L.). Besides six previously reported saponins, (25R)-furost-5-en-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, (25R)-furostane-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, and (25S)-furostane-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, and 3-O-[{α-L-rhamnopyranosyl-(1→2)}{α-L-rhamnopyranosyl-(1→4)}-β-D-glucopyranosyl]-(25S)-spirost-5-ene-3β-ol were identified for the first time as key bitter compounds in the edible spears of white asparagus by means of LC-MS/MS, LC-TOF-MS, 1D/2D-NMR spectroscopy, and hydrolysis experiments. This paper presents the isolation, structure determination, and sensory activity of these saponins. Depending on their chemical structure, the saponins identified showed human bitter recognition thresholds between 10.9 and 199.7 μmol/L (water).

  1. Bird Activity Analysis Using Avian Radar Information in Naval Air Station airport, WA

    NASA Astrophysics Data System (ADS)

    Wang, J.; Herricks, E.

    2010-12-01

    The number of bird strikes on aircraft has increased sharply over recent years and airport bird hazard management has gained increasing attention in wildlife management and control. Evaluation of bird activity near airport is very critical to analyze the hazard of bird strikes. Traditional methods for bird activity analysis using visual counting provide a direct approach to bird hazard assessment. However this approach is limited to daylight and good visual conditions. Radar has been proven to be a useful and effective tool for bird detection and movement analysis. Radar eliminates observation bias and supports consistent data collection for bird activity analysis and hazard management. In this study bird activity data from the Naval Air Station Whidbey Island was collected by Accipiter Avian Radar System. Radar data was pre-processed by filtering out non-bird noises, including traffic vehicle, aircraft, insects, wind, rainfall, ocean waves and so on. Filtered data is then statistically analyzed using MATLAB programs. The results indicated bird movement dynamics in target areas near the airport, which includes (1) the daily activity varied at dawn and dusk; (2) bird activity varied by target area due to the habitat difference; and (3) both temporal and spatial movement patterns varied by bird species. This bird activity analysis supports bird hazard evaluation and related analysis and modeling to provide very useful information in airport bird hazard management planning.

  2. Effects of genetic, pre- and post-harvest factors on phenolic content and antioxidant capacity of white asparagus spears.

    PubMed

    Papoulias, Eleftherios; Siomos, Anastasios S; Koukounaras, Athanasios; Gerasopoulos, Dimitrios; Kazakis, Evangelos

    2009-12-16

    The effects of genetic, pre-harvest (season of harvest, spear diameter, spear portion and spear tip color) and post-harvest factors (storage and domestic preparation practices, e.g., peeling and cooking) on total phenolic, flavonoid and ascorbic acid content of white asparagus spears and their correlation with antioxidant capacity (DPPH and FRAP) were studied. Results showed that genetic material was important for the total phenolic content but not season of harvest, spear diameter or storage. Violet spear tips and apical spear portions showed the largest amount of total phenolics. Peeling did not affect total phenolics in fresh asparagus, whereas it reduced their content in stored asparagus, while cooking resulted in an increase in both fresh and stored asparagus. However, the soluble extract of total phenolics and flavonoids were minor and the missing significance of phenolics and flavonoids in antioxidant capacity of white asparagus spears depends on these small amounts.

  3. Effects of Genetic, Pre- and Post-Harvest Factors on Phenolic Content and Antioxidant Capacity of White Asparagus Spears

    PubMed Central

    Papoulias, Eleftherios; Siomos, Anastasios S.; Koukounaras, Athanasios; Gerasopoulos, Dimitrios; Kazakis, Evangelos

    2009-01-01

    The effects of genetic, pre-harvest (season of harvest, spear diameter, spear portion and spear tip color) and post-harvest factors (storage and domestic preparation practices, e.g., peeling and cooking) on total phenolic, flavonoid and ascorbic acid content of white asparagus spears and their correlation with antioxidant capacity (DPPH and FRAP) were studied. Results showed that genetic material was important for the total phenolic content but not season of harvest, spear diameter or storage. Violet spear tips and apical spear portions showed the largest amount of total phenolics. Peeling did not affect total phenolics in fresh asparagus, whereas it reduced their content in stored asparagus, while cooking resulted in an increase in both fresh and stored asparagus. However, the soluble extract of total phenolics and flavonoids were minor and the missing significance of phenolics and flavonoids in antioxidant capacity of white asparagus spears depends on these small amounts. PMID:20054475

  4. A new active array MST radar system with enhanced capabilities for high resolution atmospheric observations

    NASA Astrophysics Data System (ADS)

    Durga rao, Meka; Jayaraman, Achuthan; Patra, Amit; Venkat Ratnam, Madineni; Narayana Rao, T.; Kamaraj, Pandian; Jayaraj, Katta; Kmv, Prasad; Kamal Kumar, J.; Raghavendra, J.; Prasad, T. Rajendra; Thriveni, A.; Yasodha, Polisetti

    2016-07-01

    A new version of the 53-MHz MST Radar, using the 1024 solid state Transmit-Receive Modules (TRM), necessary feeder network, multi-channel receiver and a modified radar controller has been established using the existing antenna array of 1024 crossed Yagis. The new system has been configured for steering the beam on a pulse-to-pulse basis in all 360o azimuth and 20o zenith angle, providing enhanced capability to study the Mesosphere-Stratosphere-Troposphere and Ionosphere. The multi channel receiver system has been designed for Spaced Antenna (SA) and Interferometry/ Iamging applications. The new system has also been configured for radiating in circular polarization for its application in the Ionosphere Incoherent Scatter mode. The new active array MST radar at Very-High-Frequency (53-MHz) located at Gadanki (13.45°N, 79.18°E), a tropical station in India, will be used to enhance the observations of winds, turbulence during the passage of convective events over the radar site as deep convection occurs very often at tropical latitudes. The new configuration with enhanced average power, beam agility with multi-channel experiments will be a potential source for studying middle atmosphere and ionosphere. In this paper, we present the system configuration, new capabilities and the first results obtained using the new version of the MST Radar.

  5. Measurement of Beam Lifetime and Applications for SPEAR3

    SciTech Connect

    Huang, Xiaobiao; Corbett, Jeff; /SLAC

    2011-04-05

    Beam lifetime studies for the SPEAR3 storage ring are presented. The three lifetime components are separated with lifetime measurements under various combinations of beam currents and fill patterns and vertical scraper scans. Touschek lifetime is studied with rf voltage scans and with the horizontal or vertical scrapers inserted. The measurements are explained with calculations based on the calibrated lattice model. Quantum lifetime measurements are performed with reduced longitudinal and horizontal apertures, respectively, from which we deduce the radiation energy loss down to a few keV per revolution and the horizontal beam size.

  6. Implementation of Double-Waist Chicane Optics in SPEAR3

    SciTech Connect

    Corbett, J.; Cornacchia, M.; Dao, T.; Dell'Orco, D.; Rafael, F.; Harrington, D.; Hettel, R.; Huang, X.; Nosochkov, Y.; Rabedeau, T.; Rarback, H.; Ringwall, A.; Safranek, J.; Scott, B.; Sebek, J.; Tanabe, J.; Terebilo, A.; Wermelskirchen, C.; Widmeyer, M.; Yoon, Moohyun; /POSTECH

    2006-08-16

    The SPEAR3 accelerator upgrade opened up two 7.6m racetrack straights in the magnet lattice. In one of these straights, we recently added a magnetic chicane to separate two insertion device (ID) beam lines by 10mrad. A quadrupole triplet in the center creates a ''double focus'' optics with {beta}y = 1.6m at the middle of each ID, hence the term ''double-waist chicane''. The new optics also reduced {beta}y in the four matching straights adjacent to the racetrack straights to 2.5m. In this paper, we outline design features of the optics and physical implementation of the lattice.

  7. Bunch Length and Impedance Measurements at SPEAR3

    SciTech Connect

    Corbett, W.J.; Cheng, W.X.; Fisher, A.S.; Huang, X.; /SLAC

    2011-11-02

    Streak camera measurements were made at SPEAR3 to characterize longitudinal coupling impedance. For the nominal optics, data was taken at three rf voltages and a single-bunch current range of 0-20mA. Both bunchcentroid phase shift and bunch lengthening were recorded to extract values for resistive and reactive impedance. An (R+L) and a Q=1 model were then back-substituted into the Haissinski equation and compared with raw profile data. In the short bunch (low-{alpha}) mode, distribution 'bursting' was observed.

  8. Electron Beam Lifetime in SPEAR3: Measurement and Simulation

    SciTech Connect

    Corbett, J.; Huang, X.; Lee, M.; Lui, P.; Sayyar-Rodsari, B.; /Pavilon Tech., Austin

    2007-12-19

    In this paper we report on electron beam lifetime measurements as a function of scraper position, RF voltage and bunch fill pattern in SPEAR3. We then outline development of an empirical, macroscopic model using the beam-loss rate equation. By identifying the dependence of loss coefficients on accelerator and beam parameters, a numerically-integrating simulator can be constructed to compute beam decay with time. In a companion paper, the simulator is used to train a parametric, non-linear dynamics model for the system [1].

  9. Current radar-responsive tag development activities at Sandia National Laboratories

    NASA Astrophysics Data System (ADS)

    Ormesher, Richard C.; Plummer, Kenneth W.; Wells, Lars M.

    2004-08-01

    Over the past ten years, Sandia has developed RF radar responsive tag systems and supporting technologies for various government agencies and industry partners. RF tags can function as RF transmitters or radar transponders that enable tagging, tracking, and location determination functions. Expertise in tag architecture, microwave and radar design, signal analysis and processing techniques, digital design, modeling and simulation, and testing have been directly applicable to these tag programs. In general, the radar responsive tag designs have emphasized low power, small package size, and the ability to be detected by the radar at long ranges. Recently, there has been an interest in using radar responsive tags for Blue Force tracking and Combat ID (CID). The main reason for this interest is to allow airborne surveillance radars to easily distinguish U.S. assets from those of opposing forces. A Blue Force tracking capability would add materially to situational awareness. Combat ID is also an issue, as evidenced by the fact that approximately one-quarter of all U.S. casualties in the Gulf War took the form of ground troops killed by friendly fire. Because the evolution of warfare in the intervening decade has made asymmetric warfare the norm rather than the exception, swarming engagements in which U.S. forces will be freely intermixed with opposing forces is a situation that must be anticipated. Increasing utilization of precision munitions can be expected to drive fires progressively closer to engaged allied troops at times when visual de-confliction is not an option. In view of these trends, it becomes increasingly important that U.S. ground forces have a widely proliferated all-weather radar responsive tag that communicates to all-weather surveillance. The purpose of this paper is to provide an overview of the recent, current, and future radar responsive research and development activities at Sandia National Laboratories that support both the Blue Force Tracking

  10. Asparagus Spears as a Model to Study Heteroxylan Biosynthesis during Secondary Wall Development.

    PubMed

    Song, Lili; Zeng, Wei; Wu, Aimin; Picard, Kelsey; Lampugnani, Edwin R; Cheetamun, Roshan; Beahan, Cherie; Cassin, Andrew; Lonsdale, Andrew; Doblin, Monika S; Bacic, Antony

    2015-01-01

    Garden asparagus (Asparagus officinalis L.) is a commercially important crop species utilized for its excellent source of vitamins, minerals and dietary fiber. However, after harvest the tissue hardens and its quality rapidly deteriorates because spear cell walls become rigidified due to lignification and substantial increases in heteroxylan content. This latter observation prompted us to investigate the in vitro xylan xylosyltransferase (XylT) activity in asparagus. The current model system for studying heteroxylan biosynthesis, Arabidopsis, whilst a powerful genetic system, displays relatively low xylan XylT activity in in vitro microsomal preparations compared with garden asparagus therefore hampering our ability to study the molecular mechanism(s) of heteroxylan assembly. Here, we analyzed physiological and biochemical changes of garden asparagus spears stored at 4 °C after harvest and detected a high level of xylan XylT activity that accounts for this increased heteroxylan. The xylan XylT catalytic activity is at least thirteen-fold higher than that reported for previously published species, including Arabidopsis and grasses. A biochemical assay was optimized and up to seven successive Xyl residues were incorporated to extend the xylotetraose (Xyl4) acceptor backbone. To further elucidate the xylan biosynthesis mechanism, we used RNA-seq to generate an Asparagus reference transcriptome and identified five putative xylan biosynthetic genes (AoIRX9, AoIRX9-L, AoIRX10, AoIRX14_A, AoIRX14_B) with AoIRX9 having an expression profile that is distinct from the other genes. We propose that Asparagus provides an ideal biochemical system to investigate the biochemical aspects of heteroxylan biosynthesis and also offers the additional benefit of being able to study the lignification process during plant stem maturation.

  11. Asparagus Spears as a Model to Study Heteroxylan Biosynthesis during Secondary Wall Development

    PubMed Central

    Wu, Aimin; Picard, Kelsey; Lampugnani, Edwin R.; Cheetamun, Roshan; Beahan, Cherie; Cassin, Andrew; Lonsdale, Andrew; Doblin, Monika S.; Bacic, Antony

    2015-01-01

    Garden asparagus (Asparagus officinalis L.) is a commercially important crop species utilized for its excellent source of vitamins, minerals and dietary fiber. However, after harvest the tissue hardens and its quality rapidly deteriorates because spear cell walls become rigidified due to lignification and substantial increases in heteroxylan content. This latter observation prompted us to investigate the in vitro xylan xylosyltransferase (XylT) activity in asparagus. The current model system for studying heteroxylan biosynthesis, Arabidopsis, whilst a powerful genetic system, displays relatively low xylan XylT activity in in vitro microsomal preparations compared with garden asparagus therefore hampering our ability to study the molecular mechanism(s) of heteroxylan assembly. Here, we analyzed physiological and biochemical changes of garden asparagus spears stored at 4 °C after harvest and detected a high level of xylan XylT activity that accounts for this increased heteroxylan. The xylan XylT catalytic activity is at least thirteen-fold higher than that reported for previously published species, including Arabidopsis and grasses. A biochemical assay was optimized and up to seven successive Xyl residues were incorporated to extend the xylotetraose (Xyl4) acceptor backbone. To further elucidate the xylan biosynthesis mechanism, we used RNA-seq to generate an Asparagus reference transcriptome and identified five putative xylan biosynthetic genes (AoIRX9, AoIRX9-L, AoIRX10, AoIRX14_A, AoIRX14_B) with AoIRX9 having an expression profile that is distinct from the other genes. We propose that Asparagus provides an ideal biochemical system to investigate the biochemical aspects of heteroxylan biosynthesis and also offers the additional benefit of being able to study the lignification process during plant stem maturation. PMID:25894575

  12. Ground penetrating radar for asparagus detection

    NASA Astrophysics Data System (ADS)

    Seyfried, Daniel; Schoebel, Joerg

    2016-03-01

    Ground penetrating radar is a promising technique for detection of buried objects. Recently, radar has more and more been identified to provide benefits for a plurality of applications, where it can increase efficiency of operation. One of these fields is the industrial automatic harvesting process of asparagus, which is performed so far by cutting the soil ridge at a certain height including all the asparagus spears and subsequently sieving the latter out of the soil. However, the height where the soil is cut is a critical parameter, since a wrong value leads to either damage of the roots of the asparagus plants or to a reduced crop yield as a consequence of too much biomass remaining in the soil. In this paper we present a new approach which utilizes ground penetrating radar for non-invasive sensing in order to obtain information on the optimal height for cutting the soil. Hence, asparagus spears of maximal length can be obtained, while keeping the roots at the same time undamaged. We describe our radar system as well as the subsequent digital signal processing steps utilized for extracting the information required from the recorded radar data, which then can be fed into some harvesting unit for setting up the optimal cutting height.

  13. Radar observations of magnetospheric activity during extremely quiet solar wind conditions

    NASA Astrophysics Data System (ADS)

    Walker, A. D. M.; Baker, K. B.; Pinnock, M.; Dudeney, J. R.; Rash, J. P. S.

    2002-04-01

    During a period of extremely quiet solar wind conditions from 8 to 10 March 1997, strong activity was observed by the Southern Hemisphere Auroral Radar Experiment Super Dual Auroral Radar Network radars in the Antarctic premidnight ionosphere. This activity took the form of quasiperiodic flow bursts with ionospheric drift velocities exceeding 2 km s-1. Data from the Satellite Experiments Simultaneous with Antarctic Measurements (SESAME) automated geophysical observatories in Antarctica and Defense Meteorological Satellite Program and Polar satellites are used with the radar data to study the convection flow in the southern polar ionosphere at the time of these flow bursts. The study shows that the bursts occurred with an approximate period of 12 min. Their direction was westward, and they were superimposed on a background westward flow. In the premidnight sector this is interpreted as a flow associated with dipolarization of the magnetotail tail field. There is a band of strong particle precipitation associated with the flow bursts. The location suggests that they occur deep in the magnetotail and cannot be associated with any lobe reconnection. They are at a latitude near the region where a viscously driven convection cell is expected to exist, and their sense is that of the return convection flow in such a cell. The results suggest that there is an internal magnetospheric mechanism for sporadic energy release in the magnetotail that need not be associated with changes in solar wind reconnection on the magnetopause.

  14. The Planned Soil Moisture Active Passive (SMAP) Mission L-Band Radar/Radiometer Instrument

    NASA Technical Reports Server (NTRS)

    Spencer, Michael; Wheeler, Kevin; Chan, Samuel; Piepmeier, Jeffrey; Hudson, Derek; Medeiros, James

    2011-01-01

    The Soil Moisture Active/Passive (SMAP) mission is a NASA mission identified by the NRC 'decadal survey' to measure both soil moisture and freeze/thaw state from space. The mission will use both active radar and passive radiometer instruments at L-Band. In order to achieve a wide swath at sufficiently high resolution for both active and passive channels, an instrument architecture that uses a large rotating reflector is employed. The instrument system has completed the preliminary design review (PDR) stage, and detailed instrument design has begun. In addition to providing an overview of the instrument design, two recent design modifications are discussed: 1) The addition of active thermal control to the instrument spun side to provide a more stable, settable thermal environment for the radiometer electronics, and 2) A 'sequential transmit' strategy for the two radar polarization channels which allows a single high-power amplifier to be used.

  15. An Experimental Investigation of the Functional Hypothesis and Evolutionary Advantage of Stone-Tipped Spears

    PubMed Central

    Wilkins, Jayne; Schoville, Benjamin J.; Brown, Kyle S.

    2014-01-01

    Stone-tipped weapons were a significant innovation for Middle Pleistocene hominins. Hafted hunting technology represents the development of new cognitive and social learning mechanisms within the genus Homo, and may have provided a foraging advantage over simpler forms of hunting technology, such as a sharpened wooden spear. However, the nature of this foraging advantage has not been confirmed. Experimental studies and ethnographic reports provide conflicting results regarding the relative importance of the functional, economic, and social roles of hafted hunting technology. The controlled experiment reported here was designed to test the functional hypothesis for stone-tipped weapons using spears and ballistics gelatin. It differs from previous investigations of this type because it includes a quantitative analysis of wound track profiles and focuses specifically on hand-delivered spear technology. Our results do not support the hypothesis that tipped spears penetrate deeper than untipped spears. However, tipped spears create a significantly larger inner wound cavity that widens distally. This inner wound cavity is analogous to the permanent wound cavity in ballistics research, which is considered the key variable affecting the relative ‘stopping power’ or ‘killing power’ of a penetrating weapon. Tipped spears conferred a functional advantage to Middle Pleistocene hominins, potentially affecting the frequency and regularity of hunting success with important implications for human adaptation and life history. PMID:25162397

  16. Omen: identifying potential spear-phishing targets before the email is sent.

    SciTech Connect

    Wendt, Jeremy Daniel.

    2013-07-01

    We present the results of a two year project focused on a common social engineering attack method called "spear phishing". In a spear phishing attack, the user receives an email with information specifically focused on the user. This email contains either a malware-laced attachment or a link to download the malware that has been disguised as a useful program. Spear phishing attacks have been one of the most effective avenues for attackers to gain initial entry into a target network. This project focused on a proactive approach to spear phishing. To create an effective, user-specific spear phishing email, the attacker must research the intended recipient. We believe that much of the information used by the attacker is provided by the target organization's own external website. Thus when researching potential targets, the attacker leaves signs of his research in the webserver's logs. We created tools and visualizations to improve cybersecurity analysts' abilities to quickly understand a visitor's visit patterns and interests. Given these suspicious visitors and log-parsing tools, analysts can more quickly identify truly suspicious visitors, search for potential spear-phishing targeted users, and improve security around those users before the spear phishing email is sent.

  17. An experimental investigation of the functional hypothesis and evolutionary advantage of stone-tipped spears.

    PubMed

    Wilkins, Jayne; Schoville, Benjamin J; Brown, Kyle S

    2014-01-01

    Stone-tipped weapons were a significant innovation for Middle Pleistocene hominins. Hafted hunting technology represents the development of new cognitive and social learning mechanisms within the genus Homo, and may have provided a foraging advantage over simpler forms of hunting technology, such as a sharpened wooden spear. However, the nature of this foraging advantage has not been confirmed. Experimental studies and ethnographic reports provide conflicting results regarding the relative importance of the functional, economic, and social roles of hafted hunting technology. The controlled experiment reported here was designed to test the functional hypothesis for stone-tipped weapons using spears and ballistics gelatin. It differs from previous investigations of this type because it includes a quantitative analysis of wound track profiles and focuses specifically on hand-delivered spear technology. Our results do not support the hypothesis that tipped spears penetrate deeper than untipped spears. However, tipped spears create a significantly larger inner wound cavity that widens distally. This inner wound cavity is analogous to the permanent wound cavity in ballistics research, which is considered the key variable affecting the relative 'stopping power' or 'killing power' of a penetrating weapon. Tipped spears conferred a functional advantage to Middle Pleistocene hominins, potentially affecting the frequency and regularity of hunting success with important implications for human adaptation and life history.

  18. Cardio-respiratory and daily activity monitor based on FMCW Doppler radar embedded in a wheelchair.

    PubMed

    Postolache, Octavian; Girão, Pedro Silva; Postolache, Gabriela; Gabriel, Joaquim

    2011-01-01

    Unobtrusive monitoring of the cardio-respiratory and daily activity for wheelchair users became nowadays an important challenge, considering population aging phenomena and the increasing of the elderly with chronic diseases that affect their motion capabilities. This work reports the utilization of FMCW (frequency modulated continuous wave) Doppler radar sensors embedded in a manual wheelchair to measure the cardiac and respiratory activities and the physical activity of the wheelchair user. Another radar sensor is included in the system in order to quantify the motor activity through the wheelchair traveled distance, when the user performs the manual operation of the wheelchair. A conditioning circuit including active filters and a microcontroller based primary processing module was designed and implemented to deliver the information through Bluetooth communication protocol to an Android OS tablet computer. The main capabilities of the software developed using Android SDK and Java were the signal processing of Doppler radar measurement channel signals, graphical user interface, data storage and Wi-Fi data synchronization with remote physiological and physical activity database.

  19. The Spear Horizon: First spatial analysis of the Schöningen site 13 II-4.

    PubMed

    Böhner, Utz; Serangeli, Jordi; Richter, Pascale

    2015-12-01

    The Spear Horizon (Schöningen 13 II-4) from Schöningen, Lower Saxony, Germany, is one of the most important archeological sites dating to the Middle Pleistocene. Until today, the numerous finds have only been published individually, often outside of their context. Here we present for the first time the distribution map of the Spear Horizon together with a spatial analysis of the different categories of remains (flint, bones, and woods). The finds are situated in a 10 m wide belt, which runs parallel to a former lakeshore. The distribution of faunal remains correlates closely with the distribution of flint artifacts and wooden objects. We have been able to distinguish five different sectors that can be aligned with different events or activities. The greatest density of finds was evident within an area of 11 × 15 m, where most of the horse skulls were recovered. Some of the square meters contain more than 150 finds. During the excavation the profiles were continually documented and these data help us to reconstruct the shoreline of the paleo-lake with considerable accuracy. Over a distance of 60 m, the thickness and density of the organic mud and peat layers could be reconstructed in high resolution. The distribution of finds shows no preferred orientation or selection through size. The analyses only indicate small-scale dislocations and limited taphonomic alterations. The fraction of lithic artifacts with size ranges less than 2 cm are preserved, while some smaller bone fragments are missing. Most of the wooden artifacts are in-situ, but were deformed by the ice load during the Saalian ice age. While some small charcoal remains as well as a burnt artifact have been observed, there is no evidence of burnt bones. Our results allow a first insight into the formation history of the site.

  20. The Soil Moisture Active Passive (SMAP) Radar: Measurements at High Latitudes and of Surface Freeze/Thaw State

    NASA Technical Reports Server (NTRS)

    Spencer, Michael; Dunbar, Scott; Chen, Curtis

    2013-01-01

    The Soil Moisture Active/Passive (SMAP) mission is scheduled for a late 2014 launch date. The mission will use both active radar and passive radiometer instruments at L-Band in order to achieve the science objectives of measuring soil moisture and land surface freeze-thaw state. To achieve requirements for a wide swath at sufficiently high resolution for both active and passive channels, an instrument architecture that uses a large rotating reflector is employed. In this paper, focus will be placed on the radar design. The radar will employ synthetic-aperture processing to achieve a "moderate" resolution dual-pol product over a 1000 km swath. Because the radar is operating continuously, very frequent temporal coverage will be achieved at high latitudes. This data will be used to produce a surface freeze/thaw state data product.

  1. The Soil Moisture Active Passive (SMAP): Radar Measurements at High Latitudes and of Freeze/Thaw State

    NASA Technical Reports Server (NTRS)

    Spencer, Michael; Dunbar, Scott; Chen, Curtis

    2013-01-01

    The Soil Moisture Active/Passive (SMAP) mission is scheduled for a late 2014 launch date. The mission will use both active radar and passive radiometer instruments at L-Band. In order to achieve a wide swath at sufficiently high resolution for both active and passive channels, an instrument architecture that uses a large rotating reflector is employed. In this paper, a focus will be places on the radar design and associated data products at high latitudes. The radar will employ synthetic-aperture processing to achieve a "moderate" resolution dual-pol product over a 1000 km swath. Because the radar is operating continuously, very frequent temporal coverage will be achieved at high latitudes. This data will be used, among other things, to produce a surface freeze/thaw state data product.

  2. Features associated with radar micro-Doppler signatures of various human activities

    NASA Astrophysics Data System (ADS)

    Zenaldin, Matthew; Narayanan, Ram M.

    2015-05-01

    This paper presents the results of our experimental investigation into the radar micro-Doppler signatures (MDS) of various human activities both in free-space and through-wall environments. The collection of MDS signatures was divided into two categories: stationary and forward-moving. Each category of MDS signatures encompassed a variety of movements associated with it, adding up to a total of 14 human movements. Using a 6.5-GHz C-band coherent radar, the MDS of six human subjects were gathered in free-space and through-wall environments. The MDS for these cases were analyzed in detail and the general properties of the signatures were related to their associated phenomenological characteristics. Based upon the MDS, specific features for designing detectors and classifiers of human targets performing such movements are extracted.

  3. Cramer-Rao Lower Bound Evaluation for Linear Frequency Modulation Based Active Radar Networks Operating in a Rice Fading Environment

    PubMed Central

    Shi, Chenguang; Salous, Sana; Wang, Fei; Zhou, Jianjiang

    2016-01-01

    This paper investigates the joint target parameter (delay and Doppler) estimation performance of linear frequency modulation (LFM)-based radar networks in a Rice fading environment. The active radar networks are composed of multiple radar transmitters and multichannel receivers placed on moving platforms. First, the log-likelihood function of the received signal for a Rician target is derived, where the received signal scattered off the target comprises of dominant scatterer (DS) component and weak isotropic scatterers (WIS) components. Then, the analytically closed-form expressions of the Cramer-Rao lower bounds (CRLBs) on the Cartesian coordinates of target position and velocity are calculated, which can be adopted as a performance metric to access the target parameter estimation accuracy for LFM-based radar network systems in a Rice fading environment. It is found that the cumulative Fisher information matrix (FIM) is a linear combination of both DS component and WIS components, and it also demonstrates that the joint CRLB is a function of signal-to-noise ratio (SNR), target’s radar cross section (RCS) and transmitted waveform parameters, as well as the relative geometry between the target and the radar network architectures. Finally, numerical results are provided to indicate that the joint target parameter estimation performance of active radar networks can be significantly improved with the exploitation of DS component. PMID:27929433

  4. Cramer-Rao Lower Bound Evaluation for Linear Frequency Modulation Based Active Radar Networks Operating in a Rice Fading Environment.

    PubMed

    Shi, Chenguang; Salous, Sana; Wang, Fei; Zhou, Jianjiang

    2016-12-06

    This paper investigates the joint target parameter (delay and Doppler) estimation performance of linear frequency modulation (LFM)-based radar networks in a Rice fading environment. The active radar networks are composed of multiple radar transmitters and multichannel receivers placed on moving platforms. First, the log-likelihood function of the received signal for a Rician target is derived, where the received signal scattered off the target comprises of dominant scatterer (DS) component and weak isotropic scatterers (WIS) components. Then, the analytically closed-form expressions of the Cramer-Rao lower bounds (CRLBs) on the Cartesian coordinates of target position and velocity are calculated, which can be adopted as a performance metric to access the target parameter estimation accuracy for LFM-based radar network systems in a Rice fading environment. It is found that the cumulative Fisher information matrix (FIM) is a linear combination of both DS component and WIS components, and it also demonstrates that the joint CRLB is a function of signal-to-noise ratio (SNR), target's radar cross section (RCS) and transmitted waveform parameters, as well as the relative geometry between the target and the radar network architectures. Finally, numerical results are provided to indicate that the joint target parameter estimation performance of active radar networks can be significantly improved with the exploitation of DS component.

  5. Using convolutional neural networks for human activity classification on micro-Doppler radar spectrograms

    NASA Astrophysics Data System (ADS)

    Jordan, Tyler S.

    2016-05-01

    This paper presents the findings of using convolutional neural networks (CNNs) to classify human activity from micro-Doppler features. An emphasis on activities involving potential security threats such as holding a gun are explored. An automotive 24 GHz radar on chip was used to collect the data and a CNN (normally applied to image classification) was trained on the resulting spectrograms. The CNN achieves an error rate of 1.65 % on classifying running vs. walking, 17.3 % error on armed walking vs. unarmed walking, and 22 % on classifying six different actions.

  6. Active laser radar (lidar) for measurement of corresponding height and reflectance images

    NASA Astrophysics Data System (ADS)

    Froehlich, Christoph; Mettenleiter, M.; Haertl, F.

    1997-08-01

    For the survey and inspection of environmental objects, a non-tactile, robust and precise imaging of height and depth is the basis sensor technology. For visual inspection,surface classification, and documentation purposes, however, additional information concerning reflectance of measured objects is necessary. High-speed acquisition of both geometric and visual information is achieved by means of an active laser radar, supporting consistent 3D height and 2D reflectance images. The laser radar is an optical-wavelength system, and is comparable to devices built by ERIM, Odetics, and Perceptron, measuring the range between sensor and target surfaces as well as the reflectance of the target surface, which corresponds to the magnitude of the back scattered laser energy. In contrast to these range sensing devices, the laser radar under consideration is designed for high speed and precise operation in both indoor and outdoor environments, emitting a minimum of near-IR laser energy. It integrates a laser range measurement system and a mechanical deflection system for 3D environmental measurements. This paper reports on design details of the laser radar for surface inspection tasks. It outlines the performance requirements and introduces the measurement principle. The hardware design, including the main modules, such as the laser head, the high frequency unit, the laser beam deflection system, and the digital signal processing unit are discussed.the signal processing unit consists of dedicated signal processors for real-time sensor data preprocessing as well as a sensor computer for high-level image analysis and feature extraction. The paper focuses on performance data of the system, including noise, drift over time, precision, and accuracy with measurements. It discuses the influences of ambient light, surface material of the target, and ambient temperature for range accuracy and range precision. Furthermore, experimental results from inspection of buildings, monuments

  7. Using avian radar to examine relationships among avian activity, bird strikes, and meteorological factors

    USGS Publications Warehouse

    Coates, Peter S.; Casazza, Michael L.; Halstead, Brian J.; Fleskes, Joseph P.; Laughlin, James A.

    2011-01-01

    Radar systems designed to detect avian activity at airfields are useful in understanding factors that influence the risk of bird and aircraft collisions (bird strikes). We used an avian radar system to measure avian activity at Beale Air Force Base, California, USA, during 2008 and 2009. We conducted a 2-part analysis to examine relationships among avian activity, bird strikes, and meteorological and time-dependent factors. We found that avian activity around the airfield was greater at times when bird strikes occurred than on average using a permutation resampling technique. Second, we developed generalized linear mixed models of an avian activity index (AAI). Variation in AAI was first explained by seasons that were based on average migration dates of birds at the study area. We then modeled AAI by those seasons to further explain variation by meteorological factors and daily light levels within a 24-hour period. In general, avian activity increased with decreased temperature, wind, visibility, precipitation, and increased humidity and cloud cover. These effects differed by season. For example, during the spring bird migration period, most avian activity occurred before sunrise at twilight hours on clear days with low winds, whereas during fall migration, substantial activity occurred after sunrise, and birds generally were more active at lower temperatures. We report parameter estimates (i.e., constants and coefficients) averaged across models and a relatively simple calculation for safety officers and wildlife managers to predict AAI and the relative risk of bird strike based on time, date, and meteorological values. We validated model predictability and assessed model fit. These analyses will be useful for general inference of avian activity and risk assessment efforts. Further investigation and ongoing data collection will refine these inference models and improve our understanding of factors that influence avian activity, which is necessary to inform

  8. Landscape freeze/thaw retrievals from soil moisture active passive (SMAP) L-band radar measurements

    NASA Astrophysics Data System (ADS)

    Colliander, A.; Derksen, C.

    2015-12-01

    The NASA Soil Moisture Active Passive (SMAP) mission produces a daily landscape freeze/thaw product (L3_FT_A) which provides categorical (frozen, thawed, or [inverse] transitional) classification of the surface state (for land areas north of 45°N) derived from ascending and descending orbits of SMAP high-resolution L-band radar measurements. The FT retrievals are output to 3 km resolution polar and global grids with temporal revisit of 2 days or better north of ~55°N and 3 days or better north of 45°N. The algorithm classifies the land surface freeze/thaw state based on the time series of L-band radar backscatter compared to frozen and thawed reference states. This presentation will describe pre-launch L3_FT_A algorithm implementation and evaluation using NASA/SAC-D Aquarius L-band radar data, and provide an update on the current status of the SMAP L3_FT_A product. In advance of SMAP measurements, the L3_FT_A algorithm was configured and evaluated using Aquarius measurements. While the temporal (weekly) and spatial (~100 km) resolution is much coarser than SMAP, Aquarius provides L-band radar measurements at an incidence angle (normalized to 40 degrees) which is close to SMAP. Evaluation of FT retrievals derived using both Aquarius freeze/thaw references and backscatter time series as inputs identified good agreement during the fall freeze-up period with FT flag agreement (Aquarius versus in situ) exceeding the 80% SMAP mission requirement when summarized on a monthly basis. Disagreement was greater during the spring thaw transition due in part to uncertainty in characterizing the surface state from in situ measurements and backscatter sensitivity to the onset of snow melt, independent of the soil temperature beneath the snowpack. Initial challenges for SMAP derived FT retrievals include the scale difference between the Aquarius references (~100 km) and the SMAP measurements (3 km) which is particularly problematic in areas of complex topography and/or mixed

  9. Exclusive final states from photon-photon collisions at SPEAR

    SciTech Connect

    Burke, D.L.

    1981-05-01

    Studies of exclusive final states produced by the two-photon process have been made at SPEAR by the Mark II and by the Crystal Ball Collaborations. Measurements of ..pi../sup +/..pi../sup -/ and ..pi../sup 0/..pi../sup 0/ production in the mass region 500 MeV/c/sup 2/ < m/sub ..pi pi../ < 2000 MeV/c/sup 2/ are presented. These data include strong signals from the well-known f(1270) meson. The A/sub 2/(1310) has been observed via its ..pi../sup 0/ eta decay mode and its partial width to ..gamma gamma.. has been determined. A measurement of the cross section for the reaction ..gamma gamma.. ..-->.. ..pi../sup +/..pi../sup -/..pi../sup +/..pi../sup -/ is reported. This channel is found to be small just above the four pion threshold, but exhibits a large enhancement near the rho/sup 0/rho/sup 0/ threshold.

  10. Field experiments using SPEAR: a speech control system for UGVs

    NASA Astrophysics Data System (ADS)

    Chhatpar, Siddharth R.; Blanco, Chris; Czerniak, Jeffrey; Hoffman, Orin; Juneja, Amit; Pruthi, Tarun; Liu, Dongqing; Karlsen, Robert; Brown, Jonathan

    2009-05-01

    This paper reports on a Field Experiment carried out by the Human Research and Engineering Directorate at Ft. Benning to evaluate the efficacy of using speech to control an Unmanned Ground Vehicle (UGV) concurrently with a handcontroller. The SPEAR system, developed by Think-A-Move, provides speech-control of UGVs. The system picks up user-speech in the ear canal with an in-ear microphone. This property allows it to work efficiently in high-noise environments, where traditional speech systems, employing external microphones, fail. It has been integrated with an iRobot PackBot 510 with EOD kit. The integrated system allows the hand-controller to be supplemented with speech for concurrent control. At Ft. Benning, the integrated system was tested by soldiers from the Officer Candidate School. The Experiment had dual focus: 1) Quantitative measurement of the time taken to complete each station and the cognitive load on users; 2) Qualitative evaluation of ease-of-use and ergonomics through soldier-feedback. Also of significant benefit to Think-A-Move was soldier-feedback on the speech-command vocabulary employed: What spoken commands are intuitive, and how the commands should be executed, e.g., limited-motion vs. unlimited-motion commands. Overall results from the Experiment are reported in the paper.

  11. Structure of the bipolar plasma sheath generated by SPEAR I

    SciTech Connect

    Katz, I.; Jongeward, G.A.; Davis, V.A.; Mandell, M.J.; Kuharski, R.A.; Lilley, J.R. Jr. ); Raitt, W.J. ); Cooke, D.L. ); Torbert, R.B.; Larson, G.; Rau, D. )

    1989-02-01

    The Space Power Experiment Aboard Rockets I (SPEAR I) biased two 10-cm radius spheres as high as 46,000 V positive with respect to an aluminum rocket body. The experiment measured the steady state current to the spheres and the floating potential of the rocket body. Three-dimensional calculations performed using NASCAP/LEO and POLAR 2.0 show that both ion-collecting and electron-collecting sheaths were formed. The rocket body potential with respect to the ionospheric plasma adjusted to achieve a balance between the electron current collected by the spheres and the secondary electron-enhanced ion current to the rocket body. This current balance was obtained with a large ion-collecting sheath that enveloped most of the electron-collecting sheath and reduced the area for collection of ionospheric electrons. The calculated current is in agreement with the flight measurement of a steady state current of less than 1/10 A. The calculations show that the rocket body was driven thousands of volts negative with respect to the ionospheric plasma. The calculated rocket potential is within the uncertainty of that inferred from ion spectrometer data. The current flowed through the space plasma. There was almost no direct charge transport between the spheres and the rocket body.

  12. Re-Visiting SPEAR After 25 Years (Presentation material)

    SciTech Connect

    Pietryka, M.; Gaydosh, M.; King, T.; /SLAC

    2005-08-22

    The SPEAR machine was completed in 1972. It consists of a single ring about 80 meters in diameter and started its very productive life as a positron-electron collider circulating beams up to 4 GeV. Synchrotron radiation research began almost immediately parasitically, then as half the program in the 1980s, and then became the whole program in 1991. The original network surveys used optical theodolites and invar tapes to place ring monuments in their ideal positions at constant offsets from the lines of ring quadrupoles. Optical tooling techniques were used to reference the monuments and survey offset targets on fixtures attached to the magnets. For more than 20 years neither the monuments nor magnets were restored to their ideal positions; the obvious discrepancies were simply ''feathered''. In 1992 SLC technology was used for the first time to re-measure the network and map the magnets. The discovery of many multiple-millimeter problems spurred planning for a 1995 global re-alignment. In 1995, all storage ring magnets and beamlines were mapped and moved. The band of displacements from ideal was reduced from about +/- 5mm to +/- 0.5mm. Upon start-up, beam stored without correctors.

  13. Recent results from Mark II at SPEAR and PEP

    SciTech Connect

    Strait, J.

    1982-04-01

    Three results are presented: (1) The semi-leptonic branching ratio of the ..lambda../sub c/ has been measured at SPEAR to be B(..lambda../sub c//sup +/ ..-->.. e/sup +/X) = (4.5 +- 1.7)%. (2) Properties of tau-pair production have been measured at PEP at square root S = 29 GeV: sigma/sup tau tau//sigma/sup QED/ = 0.97 +- 0.05 +- 0.06; the forward-backward asymmetry is A/sub tau tau/ = (-3.5 +- 5.0)%; inclusive branching ratios are B(tau ..-->.. 1 Prong) = (86 +- 4)%, B(tau ..-->.. 3 Prongs) = (14 +- 4)%, B(tau ..-->.. 5 Prongs) < 0.6% (95% C.L.). (3) A search has been performed for the pair production of charged, point-like, spin 0 particles. The existence of such particles can be ruled out at a 90% confidence level for 3 approx. < M approx. < 10 GeV/c/sup 2/ and branching ratio into hadrons approx. < 90%.

  14. Active laser radar systems with stochastic electromagnetic beams in turbulent atmosphere.

    PubMed

    Cai, Yangjian; Korotkova, Olga; Eyyuboğlu, Halil T; Baykal, Yahya

    2008-09-29

    Propagation of stochastic electromagnetic beams through paraxial ABCD optical systems operating through turbulent atmosphere is investigated with the help of the ABCD matrices and the generalized Huygens-Fresnel integral. In particular, the analytic formula is derived for the cross-spectral density matrix of an electromagnetic Gaussian Schell-model (EGSM) beam. We applied our analysis for the ABCD system with a single lens located on the propagation path, representing, in a particular case, the unfolded double-pass propagation scenario of active laser radar. Through a number of numerical examples we investigated the effect of local turbulence strength and lens' parameters on spectral, coherence and polarization properties of the EGSM beam.

  15. Planetary radar

    NASA Technical Reports Server (NTRS)

    Taylor, R. M.

    1980-01-01

    The radar astronomy activities supported by the Deep Space Network during June, July, and August 1980 are reported. The planetary bodies observed were Venus, Mercury, and the asteroid Toro. Data were obtained at both S and X band, and the observations were considered successful.

  16. 'Fire hardening' spear wood does slightly harden it, but makes it much weaker and more brittle.

    PubMed

    Ennos, Antony Roland; Chan, Tak Lok

    2016-05-01

    It is usually assumed that 'fire hardening' the tips of spears, as practised by hunter-gatherers and early Homo spp., makes them harder and better suited for hunting. This suggestion was tested by subjecting coppiced poles of hazel to a fire-hardening process and comparing their mechanical properties to those of naturally seasoned poles. A Shore D hardness test showed that fire treatment slightly increased the hardness of the wood, but flexural and impact tests showed that it reduced the strength and work of fracture by 30% and 36%, respectively. These results suggest that though potentially slightly sharper and more durable, fire-hardened tips would actually be more likely to break off when used, as may have been the case with the earliest known wooden tool, the Clacton spear. Fire might first have been used to help sharpen the tips of spears, and fire-hardening would have been a mostly negative side effect, not its primary purpose.

  17. Soldier experiments and assessments using SPEAR speech control system for UGVs

    NASA Astrophysics Data System (ADS)

    Brown, Jonathan; Blanco, Chris; Czerniak, Jeffrey; Hoffman, Brian; Hoffman, Orin; Juneja, Amit; Ngia, Lester; Pruthi, Tarun; Liu, Dongqing

    2010-04-01

    This paper reports on a Soldier Experiment performed by the Army Research Lab's Human Research Engineering Directorate (HRED) Field Element located at the Maneuver Center of Excellence, Ft. Benning, and a Limited Use Assessment conducted by the Marine Corps Forces Pacific Command Experimentation Center (MEC) at Camp Pendleton evaluating the effectiveness of using speech commands to control an Unmanned Ground Vehicle. SPEAR, developed by Think-A-Move, Ltd., provides speech control of UGVs. SPEAR detects user speech in the ear canal with an earpiece containing an in-ear microphone. The system design provides up to 30 dB of passive noise reduction, enabling it to work well in high-noise environments, where traditional speech systems, using external microphones, fail; it also utilizes a proprietary speech recognition engine. SPEAR has been integrated with iRobot's PackBot 510 with FasTac Kit, and with Multi-Robot Operator Control Unit (MOCU), developed by SPAWAR Systems Center Pacific. These integrated systems allow speech to supplement the hand-controller for multi-modal control of different UGV functions simultaneously. HRED's experiment measured the impact of SPEAR on reducing the cognitive load placed on UGV Operators and the time to complete specific tasks. Army NCOs and Officer School Candidates participated in this experiment, which found that speech control was faster than manual control to complete tasks requiring menu navigation, as well as reducing the cognitive load on UGV Operators. The MEC assessment examined speech commands used for two different missions: Route Clearance and Cordon and Search; participants included Explosive Ordnance Disposal Technicians and Combat Engineers. The majority of the Marines thought it was easier to complete the mission scenarios with SPEAR than with only using manual controls, and that using SPEAR improved their situational awareness. Overall results of these Assessments are reported in the paper, along with possible

  18. Status of the variable momentum compaction storage ring experiment in SPEAR

    SciTech Connect

    Tran, P.; Amiry, A.; Pellegrini, C.

    1993-09-01

    Variable momentum compaction lattices have been proposed for electron-positron colliders and synchrotron radiation sources to control synchrotron tune and bunch length. To address questions of single particle stability limits, a study has been initiated to change the SPEAR lattice into a variable momentum compaction configuration for experimental investigation of the beam dynamics. In this paper, we describe a model-based method used to transform SPEAR from the injection lattice to the low momentum compaction configuration. Experimental observations of the process are reviewed.

  19. Objective Determination of Cloud Heights and Radar Reflectivities Using a Combination of Active Remote Sensors at the ARM CART Sites.

    NASA Astrophysics Data System (ADS)

    Clothiaux, Eugene E.; Ackerman, Thomas P.; Mace, Gerald G.; Moran, Kenneth P.; Marchand, Roger T.; Miller, Mark A.; Martner, Brooks E.

    2000-05-01

    The U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Program is deploying sensitive, millimeter-wave cloud radars at its Cloud and Radiation Test Bed (CART) sites in Oklahoma, Alaska, and the tropical western Pacific Ocean. The radars complement optical devices, including a Belfort or Vaisala laser ceilometer and a micropulse lidar, in providing a comprehensive source of information on the vertical distribution of hydrometeors overhead at the sites. An algorithm is described that combines data from these active remote sensors to produce an objective determination of hydrometeor height distributions and estimates of their radar reflectivities, vertical velocities, and Doppler spectral widths, which are optimized for accuracy. These data provide fundamental information for retrieving cloud microphysical properties and assessing the radiative effects of clouds on climate. The algorithm is applied to nine months of data from the CART site in Oklahoma for initial evaluation. Much of the algorithm's calculations deal with merging and optimizing data from the radar's four sequential operating modes, which have differing advantages and limitations, including problems resulting from range sidelobes, range aliasing, and coherent averaging. Two of the modes use advanced phase-coded pulse compression techniques to yield approximately 10 and 15 dB more sensitivity than is available from the two conventional pulse modes. Comparison of cloud-base heights from the Belfort ceilometer and the micropulse lidar confirms small biases found in earlier studies, but recent information about the ceilometer brings the agreement to within 20-30 m. Merged data of the radar's modes were found to miss approximately 5.9% of the clouds detected by the laser systems. Using data from only the radar's two less-sensitive conventional pulse modes would increase the missed detections to 22%-34%. A significant remaining problem is that the radar's lower-altitude data are often

  20. A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

    NASA Technical Reports Server (NTRS)

    Kelly, Kenneth C.; Huang, John

    1999-01-01

    A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L-Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

  1. A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

    NASA Technical Reports Server (NTRS)

    Kelly, Kenneth C.; Huang, John

    2000-01-01

    A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L- Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

  2. Towards Contactless Silent Speech Recognition Based on Detection of Active and Visible Articulators Using IR-UWB Radar.

    PubMed

    Shin, Young Hoon; Seo, Jiwon

    2016-10-29

    People with hearing or speaking disabilities are deprived of the benefits of conventional speech recognition technology because it is based on acoustic signals. Recent research has focused on silent speech recognition systems that are based on the motions of a speaker's vocal tract and articulators. Because most silent speech recognition systems use contact sensors that are very inconvenient to users or optical systems that are susceptible to environmental interference, a contactless and robust solution is hence required. Toward this objective, this paper presents a series of signal processing algorithms for a contactless silent speech recognition system using an impulse radio ultra-wide band (IR-UWB) radar. The IR-UWB radar is used to remotely and wirelessly detect motions of the lips and jaw. In order to extract the necessary features of lip and jaw motions from the received radar signals, we propose a feature extraction algorithm. The proposed algorithm noticeably improved speech recognition performance compared to the existing algorithm during our word recognition test with five speakers. We also propose a speech activity detection algorithm to automatically select speech segments from continuous input signals. Thus, speech recognition processing is performed only when speech segments are detected. Our testbed consists of commercial off-the-shelf radar products, and the proposed algorithms are readily applicable without designing specialized radar hardware for silent speech processing.

  3. Towards Contactless Silent Speech Recognition Based on Detection of Active and Visible Articulators Using IR-UWB Radar

    PubMed Central

    Shin, Young Hoon; Seo, Jiwon

    2016-01-01

    People with hearing or speaking disabilities are deprived of the benefits of conventional speech recognition technology because it is based on acoustic signals. Recent research has focused on silent speech recognition systems that are based on the motions of a speaker’s vocal tract and articulators. Because most silent speech recognition systems use contact sensors that are very inconvenient to users or optical systems that are susceptible to environmental interference, a contactless and robust solution is hence required. Toward this objective, this paper presents a series of signal processing algorithms for a contactless silent speech recognition system using an impulse radio ultra-wide band (IR-UWB) radar. The IR-UWB radar is used to remotely and wirelessly detect motions of the lips and jaw. In order to extract the necessary features of lip and jaw motions from the received radar signals, we propose a feature extraction algorithm. The proposed algorithm noticeably improved speech recognition performance compared to the existing algorithm during our word recognition test with five speakers. We also propose a speech activity detection algorithm to automatically select speech segments from continuous input signals. Thus, speech recognition processing is performed only when speech segments are detected. Our testbed consists of commercial off-the-shelf radar products, and the proposed algorithms are readily applicable without designing specialized radar hardware for silent speech processing. PMID:27801867

  4. Capturing the fingerprint of Etna volcano activity in gravity and satellite radar data.

    PubMed

    Del Negro, Ciro; Currenti, Gilda; Solaro, Giuseppe; Greco, Filippo; Pepe, Antonio; Napoli, Rosalba; Pepe, Susi; Casu, Francesco; Sansosti, Eugenio

    2013-10-30

    Long-term and high temporal resolution gravity and deformation data move us toward a better understanding of the behavior of Mt Etna during the June 1995 - December 2011 period in which the volcano exhibited magma charging phases, flank eruptions and summit crater activity. Monthly repeated gravity measurements were coupled with deformation time series using the Differential Synthetic Aperture Radar Interferometry (DInSAR) technique on two sequences of interferograms from ERS/ENVISAT and COSMO-SkyMed satellites. Combining spatiotemporal gravity and DInSAR observations provides the signature of three underlying processes at Etna: (i) magma accumulation in intermediate storage zones, (ii) magmatic intrusions at shallow depth in the South Rift area, and (iii) the seaward sliding of the volcano's eastern flank. Here we demonstrate the strength of the complementary gravity and DInSAR analysis in discerning among different processes and, thus, in detecting deep magma uprising in months to years before the onset of a new Etna eruption.

  5. The MU radar with active phased array system. I - Antenna and power amplifiers. II - In-house equipment

    NASA Astrophysics Data System (ADS)

    Fukao, S.; Sato, T.; Tsuda, T.; Kato, S.; Wakasugi, K.

    1985-12-01

    The MU (middle and upper atmosphere) radar of Japan, a 46.5 MHz pulse-modulated monostatic Doppler radar with an active phased array system, is described. The system's nominal beam width is 3.6 deg, and the peak radiation power is 1 MW with maximum average power of 50 kW. The system is composed of 475 crossed three-subelement Yagi antennas and an equivalent number of solid state power amplifiers. Each Yagi antenna is driven by a transmitter-receiver module with peak output power of 2.4 kW. This configuration enables very fast and almost continuous beam steering that has not been realized by other mesosphere-stratosphere-troposphere radars. The system's antenna and power amplifiers are described, as is the in-house equipment related to transmission reception, on-line data processing, and system control.

  6. Active faults in Lebanon : kinematics and interseismic behavior measured from radar interferometry (InSAR)

    NASA Astrophysics Data System (ADS)

    Lasserre, C.; Pinel-Puysségur, B.; Vergnolle, M.; Klinger, Y.; Pathier, E.

    2012-12-01

    The Levant fault system, more than 1000 km-long, marks the limit between the Arabian and Sinaï tectonic plates, extending from the Aqaba gulf in the Red Sea to Turkey. Mostly left-lateral, it forms a transpression zone in Lebanon, associating strike-slip faults such as the Yammouneh fault and thrust faults such as the Mount Lebanon thrust. This fault system in Lebanon is at the origin of large historical earthquakes during the past two thousand years (551 AD on the thrust offshore and 1837 along the Roum fault inland, 1759 along the Rashaia and Sergaya faults). We aim at characterizing the present-day behavior of active faults in Lebanon, in particular the Yammouneh fault which did not break since 1202, to contribute to a better assessment of the seismic hazard in this region. Space geodesy techniques (GPS, InSAR) allow to quantify the present-day displacements across faults (a few mm/yr during the interseismic period), and to model stress loading and relaxation processes during the seismic cycle, at the fault scale and at the regional scale. GPS campaign measurements have been made along profiles perpendicular to the Yammouneh fault. In addition, an important archive of radar images covering Lebanon (acquired by the ERS and Envisat satellites, along descending and ascending orbits) is also available. We process ERS and Envisat radar data to obtain the average interseismic velocity field across faults over the past 15-20 years. Techniques of interferograms networks processing (MuLSAR), atmospheric phase delays correction from global atmospherical models, DEM correction and time series inversion (NSBAS) are used to overcome the main remaining limitations in the measurements accuracy (low coherence, strong atmospheric delays, long wavelength deformation signal). The final goal is to propose a modelling of the surface displacement field to quantify the present-day kinematics of active fauts in Lebanon, taking into account GPS data as well as tectonic and

  7. Through-wall imaging and characterization of human activity using ultrawideband (UWB) random noise radar

    NASA Astrophysics Data System (ADS)

    Lai, Chieh-Ping; Narayanan, Ram M.

    2005-05-01

    Recent terrorist activities and law-enforcement situations involving hostage situations underscore the need for effective through-wall imaging. Current building interior imaging systems are based on short-pulse waveforms, which require specially designed antennas to subdue unwanted ringing. In addition, periodically transmitted pulses of energy are easily recognizable by the intelligent adversary who may employ appropriate countermeasures to confound detection. A coherent polarimetric random noise radar architecture is being developed based on UWB technology and software defined radio, which has great promise in its ability to covertly image obscured targets. The main advantages of the random noise radar lie in two aspects: first, random noise waveform has an ideal "thumbtack" ambiguity function, i.e., its down range and cross range resolution can be separately controlled, thus providing unambiguous high resolution imaging at any distance; second, random noise waveform is inherently low probability of intercept (LPI) and low probability of detection (LPD), i.e., it is immune from detection, jamming, and interference. Thus, it is an ideal candidate sensor for covert imaging of obscured regions in hostile environments. The coherency in the system can be exploited to field a fully-polarimetric system that can take advantage of polarization features in target recognition. Moving personnel can also be detected using Doppler processing. Simulation studies are used to analyze backscattered signals from the walls, and humans and other targets behind the walls. Real-time data processing shows human activity behind the wall and human target tracking. The high resolution provides excellent multipath and clutter rejection.

  8. Price of dissension: the private wars of Dr. Leo L Spears, 1921-1956.

    PubMed

    Rehm, W S

    1995-06-01

    Anathema to the Denver medical community, favorite of the 1950s-era sensationalist press, Leo Spears and his hospital represented the complexities of chiropratic. A dynamic achiever in the face of adversity, this 1921 Palmer School graduate built the profession's first large hospital complex and had plans for an institution that would have been among the largest healthcare facilities in existence.

  9. Flood mapping by combining the strengths of optical and Sentinel active radar remote sensing

    NASA Astrophysics Data System (ADS)

    Winsemius, H. C.; Brakenridge, G. R.; Westerhoff, R.; Huizinga, J.; Villars, N.; Bishop, C.

    2012-04-01

    Flood mapping with remote sensing plays an important role in large scale disaster management procedures. For this purpose, the Dartmouth Flood Observatory (DFO) gained experience since 1993 with the production of flood maps from optical satellite imagery and has currently established, together with NASA collaborators, a fully automated, global, near real-time service. Another consortium is also presently working on an automated, near real-time, global flood mapping procedure called the 'Global Flood Observatory' (GFO), which will make use of high resolution Sentinel data. The procedure is currently tested on Envisat active radar (ASAR) imagery. Both the DFO and GFO projects provide open data output of their data and maps. The optical and radar approaches to flood mapping each have advantages and suffer from shortcomings. Optical remote sensing via the U.S. MODIS and VIIRS sensors is constrained by cloud cover but can attain a high revisit frequency (>2 /day), whereas the Envisat ASAR is not affected by cloud cover, but uses a lower revisit frequency (generally once/3 days, depending on the location). In this contribution, we demonstrate the combination of both approaches into one flood mapping result. This results in improved flood mapping in a case study over the Chao Phraya basin (Bangkok surroundings) during the recent October-November 2011 extreme flooding. The combined map shows that during overpass, ASAR reveals flooded regions over cloud-obscured areas, which clearly follow elevated features in the landscape such as roads, embankments and railways. Meanwhile, the high frequency of delivery of the optical information ensures timely information. Also, the quite different water classification methods used for the optical and ASAR data sources show good agreement and have been successfully merged into one GIS data product. This can also be automatically generated and disseminated on a global basis.

  10. Radar imaging of winter seismic survey activity in the National Petroleum Reserve-Alaska

    USGS Publications Warehouse

    Jones, Benjamin M.; Rykhus, Russ; Lu, Zhiming; Arp, C.D.; Selkowitz, D.J.

    2008-01-01

    During the spring of 2006, Radarsat-1 synthetic aperture radar (SAR) imagery was acquired on a continual basis for the Teshekpuk Lake Special Area (TLSA), in the northeast portion of the National Petroleum Reserve, Alaska (NPR-A) in order to monitor lake ice melting processes. During data processing, it was discovered that the Radarsat-1 imagery detected features associated with winter seismic survey activity. Focused analysis of the image time series revealed various aspects of the exploration process such as the grid profile associated with the seismic line surveys as well as trails and campsites associated with the mobile survey crews. Due to the high temporal resolution of the dataset it was possible to track the progress of activities over a one month period. Spaceborne SAR imagery can provide information on the location of winter seismic activity and could be used as a monitoring tool for land and resource managers as increased petroleum-based activity occurs in the TLSA and NPR-A.

  11. TRMM radar

    NASA Technical Reports Server (NTRS)

    Okamoto, Kenichi

    1993-01-01

    The results of a conceptual design study and the performance of key components of the Bread Board Model (BBM) of the Tropical Rainfall Measuring Mission (TRMM) radar are presented. The radar, which operates at 13.8 GHz and is designed to meet TRMM mission objectives, has a minimum measurable rain rate of 0.5 mm/h with a range resolution of 250 m, a horizontal resolution of about 4 km, and a swath width of 220 km. A 128-element active phased array system is adopted to achieve contiguous scanning within the swath. The basic characteristics of BBM were confirmed by experiments. The development of EM started with the cooperation of NASDA and CRL.

  12. The Effects of High Frequency ULF Wave Activity on the Spectral Characteristics of Coherent HF Radar Returns

    NASA Astrophysics Data System (ADS)

    Wright, D. M.; Yeoman, T. K.; Woodfield, E. E.

    2003-12-01

    It is now a common practice to employ ground-based radars in order to distinguish between those regions of the Earth's upper atmosphere which are magnetically conjugate to open and closed field lines. Radar returns from ionospheric irregularities inside the polar cap and cusp regions generally exhibit large spectral widths in contrast to those which exist on closed field lines at lower latitudes. It has been suggested that the so-called Spectral Width Boundary (SWB) might act as a proxy for the open-closed field line boundary (OCFLB), which would then be an invaluable tool for investigating reconnection rates in the magnetosphere. The exact cause of the increased spectral widths observed at very high latitudes is still subject to considerable debate. Several mechanisms have been proposed. This paper compares a dusk-sector interval of coherent HF radar data with measurements made by an induction coil magnetometer located at Tromso, Norway (66° N geomagnetic). On this occasion, a series of transient regions of radar backscatter exhibiting large spectral widths are accompanied by increases in spectral power of ULF waves in the Pc1-2 frequency band. These observations would then, seem to support the possibility that high frequency magnetospheric wave activity at least contribute to the observed spectral characteristics and that such wave activity might play a significant role in the cusp and polar cap ionospheres.

  13. Probabilistic constraints from existing and future radar imaging on volcanic activity on Venus

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.

    2015-11-01

    We explore the quantitative limits that may be placed on Venus' present-day volcanic activity by radar imaging of surface landforms. The apparent nondetection of new lava flows in the areas observed twice by Magellan suggests that there is a ~60% chance that the eruption rate is ~1 km3/yr or less, using the eruption history and area/volume flow geometry of terrestrial volcanoes (Etna, Mauna Loa and Merapi) as a guide. However, if the detection probability of an individual flow is low (e.g. ~10%) due to poor resolution or quality and unmodeled viewing geometry effects, the constraint (<10 km3/yr) is not useful. Imaging at Magellan resolution or better of only ~10% of the surface area of Venus on a new mission (30 years after Magellan) would yield better than 99% chance of detecting a new lava flow, even if the volcanic activity is at the low end of predictions (~0.01 km3/yr) and is expressed through a single volcano with a stochastic eruption history. Closer re-examination of Magellan data may be worthwhile, both to search for new features, and to establish formal (location-dependent) limits on activity against which data from future missions can be tested. While Magellan-future and future-future comparisons should offer much lower detection thresholds for erupted volumes, a probabilistic approach will be required to properly understand the implications.

  14. Development of Coherent Laser Radar for Space Situational Awareness Applications

    NASA Astrophysics Data System (ADS)

    Prasad, N.; DiMarcantonio, A.

    2013-09-01

    NASA Langley Research Center (LaRC) is working on an innovative and high performance mobile coherent laser radar (ladar) system known as ExoSPEAR for space situational awareness applications in LEO and beyond. Based on continuously agile pulse doublet technology, the 100 W, nanosecond class, near-IR laser based coherent ladar is being developed for short dwell time measurements of resident space objects (RSOs). ExoSPEAR system is designed to provide rapid and precision tracking of RSOs over very long ranges. The goal is to demonstrate mm-class range resolution, mm/s class velocity resolution and microrad angular resolution with significantly reduced error-covariance in track accuracy. Precise orbit determination would help in advancing functionality of early warning systems for tracking uncooperative targets for planetary protection applications. Furthermore, improvements in resolution of micromotion measurements would enhance our understanding of astrodymanical properties of resident space objects. In this paper, salient features of the evolution and current experimental status of ExoSPEAR ladar architecture will be discussed. Performance simulations illustrating the dependence of range and velocity precision in LEO orbits on ladar power aperture product will be presented. Estimated limits on detectable optical cross sections of RSOs in LEO orbits will be analyzed.

  15. Noncontact accurate measurement of cardiopulmonary activity using a compact quadrature Doppler radar sensor.

    PubMed

    Hu, Wei; Zhao, Zhangyan; Wang, Yunfeng; Zhang, Haiying; Lin, Fujiang

    2014-03-01

    The designed sensor enables accurate reconstruction of chest-wall movement caused by cardiopulmonary activities, and the algorithm enables estimation of respiration, heartbeat rate, and some indicators of heart rate variability (HRV). In particular, quadrature receiver and arctangent demodulation with calibration are introduced for high linearity representation of chest displacement; 24-bit ADCs with oversampling are adopted for radar baseband acquisition to achieve a high signal resolution; continuous-wavelet filter and ensemble empirical mode decomposition (EEMD) based algorithm are applied for cardio/pulmonary signal recovery and separation so that accurate beat-to-beat interval can be acquired in time domain for HRV analysis. In addition, the wireless sensor is realized and integrated on a printed circuit board compactly. The developed sensor system is successfully tested on both simulated target and human subjects. In simulated target experiments, the baseband signal-to-noise ratio (SNR) is 73.27 dB, high enough for heartbeat detection. The demodulated signal has 0.35% mean squared error, indicating high demodulation linearity. In human subject experiments, the relative error of extracted beat-to-beat intervals ranges from 2.53% to 4.83% compared with electrocardiography (ECG) R-R peak intervals. The sensor provides an accurate analysis for heart rate with the accuracy of 100% for p = 2% and higher than 97% for p = 1%.

  16. Capturing the fingerprint of Etna volcano activity in gravity and satellite radar data

    PubMed Central

    Negro, Ciro Del; Currenti, Gilda; Solaro, Giuseppe; Greco, Filippo; Pepe, Antonio; Napoli, Rosalba; Pepe, Susi; Casu, Francesco; Sansosti, Eugenio

    2013-01-01

    Long-term and high temporal resolution gravity and deformation data move us toward a better understanding of the behavior of Mt Etna during the June 1995 – December 2011 period in which the volcano exhibited magma charging phases, flank eruptions and summit crater activity. Monthly repeated gravity measurements were coupled with deformation time series using the Differential Synthetic Aperture Radar Interferometry (DInSAR) technique on two sequences of interferograms from ERS/ENVISAT and COSMO-SkyMed satellites. Combining spatiotemporal gravity and DInSAR observations provides the signature of three underlying processes at Etna: (i) magma accumulation in intermediate storage zones, (ii) magmatic intrusions at shallow depth in the South Rift area, and (iii) the seaward sliding of the volcano's eastern flank. Here we demonstrate the strength of the complementary gravity and DInSAR analysis in discerning among different processes and, thus, in detecting deep magma uprising in months to years before the onset of a new Etna eruption. PMID:24169569

  17. Synthetic aperture radar image segmentation based on edge-region active contour model

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Wen, Xianbin; Xu, Haixia; Meng, Qingxia

    2016-07-01

    An energy functional is proposed based on an edge-region active contour model for synthetic aperture radar (SAR) image segmentation. The proposed energy functional not only has a desirable property to process inhomogeneous regions in SAR images, but also shows satisfactory convergence speed. Our proposed energy functional consists of two main energy terms: an edge-region term and a regularization term. The edge-region term is derived from a Gamma model and gradient term model, which can process the speckle noises and drive the motion of the curves toward desired locations. The regularization term is not only able to maintain a desired shape of the evolution curves but also has a strong smoothing curve effect and avoid the occurrence of small, isolated regions in the final segmentation. Finally, the gradient descent flow method is introduced for minimizing our energy functional. A desirable feature of the proposed method is that it is not sensitive to the contour initialization. Compared with other methods, experimental results show that the proposed approach has promising edge detection results on the synthetic and real SAR images.

  18. SPEAR 3 flight analysis: Grounding by neutral gas release, and magnetic field effects on current distribution

    NASA Astrophysics Data System (ADS)

    Mandell, M. J.; Jongeward, G. A.; Cooke, D. L.; Raitt, W. J.

    1998-01-01

    The Space Power Experiment Aboard Rockets (SPEAR) 3 experiment was launched on March 15, 1993, to test grounding devices for negative payloads. In this paper we review two aspects of the high-altitude flight data and compare them with preflight predictions. The SPEAR 3 neutral gas release experiment studied a grounding mechanism observed on previous flights during attitude control system (ACS) firings. Preflight calculations using Paschen law physics generalized to three dimensions predicted that the high rate gas release (about one order of magnitude below normal ACS) would reduce the rocket potential to within 200-300 V of plasma ground. The flight data is well fit by a value of -225V. Orientation relative to Earth's magnetic field had no effect on the floating potential or grounding operations but had a large effect on the portion of the current collected by the boom. We compare these flight measurements with preflight calculations made with the DynaPAC computer code.

  19. Radar principles

    NASA Technical Reports Server (NTRS)

    Sato, Toru

    1989-01-01

    Discussed here is a kind of radar called atmospheric radar, which has as its target clear air echoes from the earth's atmosphere produced by fluctuations of the atmospheric index of refraction. Topics reviewed include the vertical structure of the atmosphere, the radio refractive index and its fluctuations, the radar equation (a relation between transmitted and received power), radar equations for distributed targets and spectral echoes, near field correction, pulsed waveforms, the Doppler principle, and velocity field measurements.

  20. Ground penetrating radar and active seismic investigation of stratigraphically verified pyroclastic deposits

    NASA Astrophysics Data System (ADS)

    Gase, A.; Bradford, J. H.; Brand, B. D.

    2015-12-01

    We conducted ground-penetrating radar (GPR) and active seismic surveys in July and August, 2015 parallel to outcrops of the pyroclastic density current deposits of the May 18th, 1980 eruption of Mount St. Helens (MSH), Washington. The primary objective of this study is to compare geophysical properties that influence electromagnetic and elastic wave velocities with stratigraphic parameters in the un-saturated zone. The deposits of interest are composed of pumice, volcanic ash, and lava blocks comprising a wide range of intrinsic porosities and grain sizes from sand to boulders. Single-offset GPR surveys for reflection data were performed with a Sensors and Software pulseEKKO Pro 100 GPR using 50 MHz, 100 MHz, and 200 MHz antennae. GPR data processing includes time-zero correction, dewow filter, migration, elevation correction. Multi-offset acquisition with 100 MHz antennae and offsets ranging from 1 m to 16 m are used for reflection tomography to create 2 D electromagnetic wave velocity models. Seismic surveys are performed with 72 geophones spaced at two meters using a sledge hammer source with shot points at each receiver point. We couple p- wave refraction tomography with Rayleigh wave inversion to compute Vp/Vs ratios. The two geophysical datasets are then compared with stratigraphic information to illustrate the influence of lithological parameters (e.g. stratification, grain-size distribution, porosity, and sorting) on geophysical properties of unsaturated pyroclastic deposits. Future work will include joint petrophysical inversion of the multiple datasets to estimate porosity and water content in the unsaturated zone.

  1. Radar observations of high-latitude lower-thermospheric and upper-mesospheric winds and their response to geomagnetic activity

    SciTech Connect

    Johnson, R.M.

    1987-01-01

    Observations made by the Chatanika, Alaska, incoherent scatter radar during the summer months of 1976 to 1081 are analyzed to obtain high resolution lower-thermospheric neutral winds. Average winds and their tidal components are presented and compared to previous observational and model results. Upper-mesospheric neutral-wind observations obtained by the Poke Flat, Alaska Mesosphere-Stratosphere-Troposphere (MST) radar during the summer months of 1980 to 1982 are investigated statistically for evidence of variations due to geomagnetic activity. Observation of upper-mesospheric neutral winds made during two energetic Solar Proton Events (SPEs) by the Poker Flat, MST radar are presented. These results allow the low-altitude limits of magnetospheric coupling to the neutral atmosphere to be determined. Lower-thermospheric neutral winds are coupled to the ion convection driven by typical magnetospheric forcing above about 100 km. Coupling to lower atmospheric levels does not occur except during intervals of extreme disturbance of the magnetosphere-ionosphere-thermosphere system which are also accompanied by dramatically increased ionization in the high-latitude mesosphere, such as SPEs.

  2. Equatorial MU Radar project

    NASA Astrophysics Data System (ADS)

    Yamamoto, Mamoru; Hashiguchi, H.; Tsuda, Toshitaka; Yamamoto, Masayuki

    Research Institute for Sustainable Humanosphere, Kyoto University (RISH) has been studying the atmosphere by using radars. The first big facility was the MU (Middle and Upper atmosphere) radar installed in Shiga, Japan in 1984. This is one of the most powerful and multi-functional radar, and is successful of revealing importance of atmospheric waves for the dynamical vertical coupling processes. The next big radar was the Equatorial Atmosphere Radar (EAR) installed at Kototabang, West Sumatra, Indonesia in 2001. The EAR was operated under close collaboration with LAPAN (Indonesia National Institute for Aeronautics and Space), and conducted the long-term continuous observations of the equatorial atmosphere/ionosphere for more than 10 years. The MU radar and the EAR are both utilized for inter-university and international collaborative research program for long time. National Institute for Polar Research (NIPR) joined EISCAT Scientific Association together with Nagoya University, and developed the PANSY radar at Syowa base in Antarctica as a joint project with University of Tokyo. These are the efforts of radar study of the atmosphere/ionosphere in the polar region. Now we can find that Japan holds a global network of big atmospheric/ionospheric radars. The EAR has the limitation of lower sensitivity compared with the other big radars shown above. RISH now proposes a plan of Equatorial MU Radar (EMU) that is to establish the MU-radar class radar next to the EAR. The EMU will have an active phased array antenna with the 163m diameter and 1055 cross-element Yagis. Total output power of the EMU will be more than 500kW. The EMU can detect turbulent echoes from the mesosphere (60-80km). In the ionosphere incoherent-scatter observations of plasma density, drift, and temperature would be possible. Multi-channel receivers will realize radar-imaging observations. The EMU is one of the key facilities in the project "Study of coupling processes in the solar-terrestrial system

  3. Use of DOE SGP Radars in Support of ASR Modeling Activities

    SciTech Connect

    Rutledge, Steven A.

    2015-12-13

    The objective of this work was to use the DOE Southern Great Plains (SGP) precipitation radars to investigate physical characteristics of clouds and precipitation, and use this knowledge in support of DOE ASR modeling efforts. The goal was to develop an integrated data set based on the SGP instrumentation to yield statistically robust fields to aid in the task of verifying simulated cloud dynamical and microphysical fields. For this effort we relied heavily on the ARM scanning precipitation radars, X-SAPR’s and C-SAPR, and also incorporating data from wind profilers, surface disdrometers and the nearby WSR-88D radar, KVNX. Initially we lent our expertise to quality controlling the data from the newly installed ARM radars, particularly the X-band polarimetric data, and additionally assessed automatic radial velocity unfolding algorithms developed by other ASR researchers. We focused our efforts on four cases from the MC3E field campaign in 2011 and developed a dataset including microphysical information derived from hydrometeor identification and kinematic analysis using multiple-Doppler retrieval techniques. This dataset became a PI product and was released to the community in 2014. This analysis was used to investigate the source of big drops (> 5 mm) observed with disdrometers at the surface. It was found that the big drops were coincident with the strongest updrafts, suggesting they resulted from the melting of large precipitation ice, likely hail. We teamed up with W-K Tao and T. Matsui to statistically compare radar-derived observational kinematics and microphysics to WRF model output for the 25 April 2011. Comparisons highlighted some areas where the model may need improvement, such as generating too much hail and big drops, as well as overly-strong updrafts and overly-weak of downdrafts.

  4. Impacts of pesticide mixtures in European rivers as predicted by the Species Sensitivity Distribution (SSD) models and SPEAR bioindication

    NASA Astrophysics Data System (ADS)

    Jesenska, Sona; Liess, Mathias; Schäfer, Ralf; Beketov, Mikhail; Blaha, Ludek

    2013-04-01

    Species sensitivity distribution (SSD) is statistical method broadly used in the ecotoxicological risk assessment of chemicals. Originally it has been used for prospective risk assessment of single substances but nowadays it is becoming more important also in the retrospective risk assessment of mixtures, including the catchment scale. In the present work, SSD predictions (impacts of mixtures consisting of 25 pesticides; data from several catchments in Germany, France and Finland) were compared with SPEAR-pesticides, which a bioindicator index based on biological traits responsive to the effects of pesticides and post-contamination recovery. The results showed statistically significant correlations (Pearson's R, p<0.01) between SSD (predicted msPAF values) and values of SPEAR-pesticides (based on field biomonitoring observations). Comparisons of the thresholds established for the SSD and SPEAR approaches (SPEAR-pesticides=45%, i.e. LOEC level, and msPAF = 0.05 for SSD, i.e. HC5) showed that use of chronic toxicity data significantly improved the agreement between the two methods but the SPEAR-pesticides index was still more sensitive. Taken together, the validation study shows good potential of SSD models in predicting the real impacts of micropollutant mixtures on natural communities of aquatic biota.

  5. Radar micro-Doppler based human activity classification for indoor and outdoor environments

    NASA Astrophysics Data System (ADS)

    Zenaldin, Matthew; Narayanan, Ram M.

    2016-05-01

    This paper presents the results of our experimental investigation into how different environments impact the classification of human motion using radar micro-Doppler (MD) signatures. The environments studied include free space, through-thewall, leaf tree foliage, and needle tree foliage. Results on presented on classification of the following three motions: crawling, walking, and jogging. The classification task was designed how to best separate these movements. The human motion data were acquired using a monostatic coherent Doppler radar operating in the C-band at 6.5 GHz from a total of six human subjects. The received signals were analyzed in the time-frequency domain using the Short-time Fourier Transform (STFT) which was used for feature extraction. Classification was performed using a Support Vector Machine (SVM) using a Radial Basis Function (RBF). Classification accuracies in the range 80-90% were achieved to separate the three movements mentioned.

  6. Spaceborne meteorological radar studies

    NASA Technical Reports Server (NTRS)

    Meneghini, R.

    1988-01-01

    Various radar designs and methods are studied for the estimation of rainfall parameters from space. An immediate goal is to support the development of the spaceborne radar that has been proposed for the Tropical Rain Measuring Mission (TRMM). The effort is divided into two activities: a cooperative airborne rain measuring experiment with the Radio Research Laboratory of Japan (RRL), and the modelling of spaceborne weather radars. An airborne rain measuring experiment was conducted at Wallops Flight Facility in 1985 to 1986 using the dual-wavelength radar/radiometer developed by RRL. The data are presently being used to test a number of methods that are relevant to spaceborne weather radars. An example is shown of path-averaged rain rates as estimated from three methods: the standard reflectivity rain rate method (Z-R), a dual-wavelength method, and a surface reference method. The results from the experiment shows for the first time the feasibility of using attenuation methods from space. The purposes of the modelling are twofold: to understand in a quantitative manner the relationships between a particular radar design and its capability for estimating precipitation parameters and to help devise and test new methods. The models are being used to study the impact of various TRMM radar designs on the accuracy of rain rate estimation as well as to test the performance of range-profiling algorithms, the mirror-image method, and some recently devised graphical methods for the estimation of the drop size distribution.

  7. Design and Implementation of an Active Calibration System for Weather Radars

    DTIC Science & Technology

    2008-09-01

    Chassis( FPGAs ) and the LabVIEW FPGA module for programming commands that can be auto-compiled into VHDL for the CompactRIO Chassis( FPGAs ). 129 APPENDIX... sources , gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden...unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) Weather radars permit meteorological quantities such as rainfall rate and wind

  8. Planetary Radar

    NASA Technical Reports Server (NTRS)

    Neish, Catherine D.; Carter, Lynn M.

    2015-01-01

    This chapter describes the principles of planetary radar, and the primary scientific discoveries that have been made using this technique. The chapter starts by describing the different types of radar systems and how they are used to acquire images and accurate topography of planetary surfaces and probe their subsurface structure. It then explains how these products can be used to understand the properties of the target being investigated. Several examples of discoveries made with planetary radar are then summarized, covering solar system objects from Mercury to Saturn. Finally, opportunities for future discoveries in planetary radar are outlined and discussed.

  9. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1987-09-28

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

  10. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1989-01-01

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole.

  11. Modes on a short SPEAR bunch as observed with a streak camera

    SciTech Connect

    Sabersky, A.P.; Donald, M.H.R.

    1981-02-01

    The longitudinal structure of electron bunches in the storage ring SPEAR on a single pass was studied with time resolution approx. 10 ps. The measuring instrument used is an image-converter streak camera, a specialized device heretofore used mostly by laser workers. Unexpectedly, under some conditions the charge in a single RF bucket breaks up into two short sub-bunches which seem to rotate about a common center in energy-phase space. No evidence is seen for other, higher-frequency structure on the bunches.

  12. Spaceborne radar

    NASA Technical Reports Server (NTRS)

    Moore, R. K.; Eckerman, J.; Meneghini, R.; Atlas, D.; Boerner, W. M.; Cherry, S.; Clark, J. F.; Doviak, R. J.; Goldhirsh, J.; Lhermitte, R. M.

    1981-01-01

    The spaceborne radar panel considered how radar could be used to measure precipitation from satellites. The emphasis was on how radar could be used with radiometry (at microwave, visible (VIS), and infrared (IR) wavelengths) to reduce the uncertainties of measuring precipitation with radiometry alone. In addition, the fundamental electromagnetic interactions involved in the measurements were discussed to determine the key work areas for research and development to produce effective instruments. Various approaches to implementing radar systems on satellites were considered for both shared and dedicated instruments. Finally, a research and development strategy was proposed for establishing the parametric relations and retrieval algorithms required for extracting precipitation information from the radar and associated radiometric data.

  13. Beam studies at the SPEAR3 synchrotron using a digital optical mask

    SciTech Connect

    Zhang, H. D.; Fiorito, R. B.; Corbett, J.; Shkvarunets, A. G.; Tian, K.; Fisher, A.

    2016-05-01

    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500 mA circulating in the storage ring (equivalently 392 nC). Each injection pulse contains 40–80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during user operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by imaging the visible component of the synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera, makes it possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, a high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  14. Beam studies at the SPEAR3 synchrotron using a digital optical mask

    NASA Astrophysics Data System (ADS)

    Zhang, H. D.; Fiorito, R. B.; Corbett, J.; Shkvarunets, A. G.; Tian, K.; Fisher, A.

    2016-05-01

    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500 mA circulating in the storage ring (equivalently 392 nC). Each injection pulse contains 40-80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during user operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by imaging the visible component of the synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera, makes it possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, a high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  15. Optical and Radar Satellite Remote Sensing for Large Area Analysis of Landslide Activity in Southern Kyrgyzstan, Central Asia

    NASA Astrophysics Data System (ADS)

    Roessner, S.; Behling, R.; Teshebaeva, K. O.; Motagh, M.; Wetzel, H. U.

    2014-12-01

    The presented work has been investigating the potential of optical and radar satellite remote sensing for the spatio-temporal analysis of landslide activity at a regional scale along the eastern rim of the Fergana Basin representing the area of highest landslide activity in Kyrgyzstan. For this purpose a multi-temporal satellite remote sensing database has been established for a 12.000 km2 study area in Southern Kyrgyzstan containing a multitude of optical data acquired during the last 28 years as well as TerraSAR-X and ALOS-PALSAR acquired since 2007. The optical data have been mainly used for creating a multi-temporal inventory of backdated landslide activity. For this purpose an automated approach for object-oriented multi-temporal landslide detection has been developed which is based on the analysis of temporal NDVI-trajectories complemented by relief information to separate landslide-related surface changes from other land cover changes. Applying the approach to the whole study area using temporal high resolution RapidEye time series data has resulted in the automated detection of 612 landslide objects covering a total area of approx. 7.3 km². Currently, the approach is extended to the whole multi-sensor time-series database for systematic analysis of longer-term landslide occurrence at a regional scale. Radar remote sensing has been focussing on SAR Interferometry (InSAR) to detect landslide related surface deformation. InSAR data were processed by repeat-pass interferometry using the DORIS and SARScape software. To better assess ground deformation related to individual landslide objects, InSAR time-series analysis has been applied using the Small Baseline Subset (SBAS) method. Analysis of the results in combination with optical data and DEM information has revealed that most of the derived deformations are caused by slow movements in areas of already existing landslides indicating the reactivation of older slope failures. This way, InSAR analysis can

  16. 1990 Activity report for 1986-1992

    SciTech Connect

    Cantwell, K.

    1996-01-01

    As discussed in last year`s Activity Report, a fairly complete analysis of SPEAR problems was performed in concert with SLAC, and a major maintenance/improvement process was initiated in the spring of 1989. This run made it apparent that SPEAR will remain a very useful and impressive synchrotron radiation storage ring for at least a decade, given a steady maintenance and improvement program. More details about SPEAR functioning during the run, as well as SPEAR improvements, are contained in Chapter I. The formal SPEAR injector construction project was completed in November, 1990, on-time and on-budget. Although DOE was not able to provide anticipated FY90 commissioning funds, preliminary commissioning was performed and 2.3 GeV injection to SPEAR was demonstrated. A discussion of the Injector project is contained in Chapter II. Commissioning of the injector and the injector/SPEAR complex is continuing in 1991 with Users participating during the May-September period. This user participation allowed normal experimentation, so that systems could be tested critically, but with the commissioning process having higher priority than data acquisition. Another major event in 1990 was the full dedication of SPEAR to the synchrotron radiation program. Previously SPEAR was considered a high energy physics machine that was partially dedicated to synchrotron radiation. The full dedication means that the accelerator can be modified and improved for synchrotron radiation research. Despite the heavy emphasis on completing the Injector, many beam line improvements were achieved, as described in Chapter IV. Among these was the optimization of stations 6-2 and 10-2, the provision of a considerably larger hutch for Station 1-5, which contains the area detector diffractometer, and the introduction of white light capability on 10-2. The provision of good beam during the month of April made an appreciable amount of experimentation possible. These and other runs are described in Chapter VI.

  17. Multi-damage detection with embedded ultrasonic structural radar algorithm using piezoelectric wafer active sensors through advanced signal processing

    NASA Astrophysics Data System (ADS)

    Yu, Lingyu; Giurgiutiu, Victor

    2005-05-01

    The embedded ultrasonic structural radar (EUSR) algorithm was developed by using piezoelectric wafer active sensor (PWAS) array to detect defects within a large area of a thin-plate specimen. EUSR has been verified to be effective for detecting a single crack either at a broadside or at an offside position. In this research, advanced signal processing techniques were included to enhance inspection image quality and detect multiple damage. The signal processing methods include discrete wavelet transform for signal denoising, short-time Fourier transform and continuous wavelet transform for time-frequency analysis, continuous wavelet transform for frequency filtering, and Hilbert transform for envelope extraction. All these signal processing modules were implemented by developing a graphical user-friendly interface program in LabVIEW. The paper starts with an introduction of embedded ultrasonic structural radar algorithm, followed with the theoretical aspect of the phased array signal processing method. Then, the mathematical algorithms for advanced signal processing are introduced. In the end, laboratory experimental results are presented to show how efficiently the improved EUSR works. The results are analyzed and EUSR is concluded to have been improved by using the advanced signal processing techniques. The improvements include: 1) EUSR is able to provide better image of the specimen under monitoring; 2) it is able to detect multi-damage such as several cracks; 3) it is able to identify different damage types.

  18. Strombolian surface activity regimes at Yasur volcano, Vanuatu, as observed by Doppler radar, infrared camera and infrasound

    NASA Astrophysics Data System (ADS)

    Meier, K.; Hort, M.; Wassermann, J.; Garaebiti, E.

    2016-08-01

    In late 2008 we recorded a continuous multi-parameter data set including Doppler radar, infrared and infrasound data at Yasur volcano, Vanuatu. Our recordings cover a transition in explosive style from ash-rich to ash-free explosions followed again by a phase of high ash discharge. To assess the present paradigm of Strombolian behavior in this study we investigate the geophysical signature of these different explosive episodes and compare our results to observations at Stromboli volcano, Italy. To this end we characterize Yasur's surface activity in terms of material movement, temperature and excess pressure. The joint temporal trend in these data reveals smooth variations of surface activity and regime-like persistence of individual explosion forms over days. Analysis of all data types shows ash-free and ash-rich explosive styles similar to those found at Stromboli volcano. During ash-free activity low echo powers, high explosion velocities and high temperatures result from the movement of isolated hot ballistic clasts. In contrast, ash-rich episodes exhibit high echo powers, low explosion velocities and low temperatures linked to the presence of colder ash-rich plumes. Furthermore ash-free explosions cause high excess pressure signals exhibiting high frequencies opposed to low-amplitude, low-frequency signals accompanying ash-rich activity. To corroborate these findings we compare fifteen representative explosions of each explosive episode. Explosion onset velocities derived from Doppler radar and infrared camera data are in excellent agreement and consistent with overall observations in each regime. Examination of infrasound recordings likewise confirms our observations, although a weak coupling between explosion velocity and excess pressure indicates changes in wave propagation. The overall trend in explosion velocity and excess pressure however demonstrates a general correlation between explosive style and explosion intensity, and points to stability of the

  19. COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar:" ongoing research activities and mid-term results

    NASA Astrophysics Data System (ADS)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Slob, Evert; Tosti, Fabio

    2015-04-01

    This work aims at presenting the ongoing activities and mid-term results of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar.' Almost three hundreds experts are participating to the Action, from 28 COST Countries (Austria, Belgium, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Malta, Macedonia, The Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom), and from Albania, Armenia, Australia, Egypt, Hong Kong, Jordan, Israel, Philippines, Russia, Rwanda, Ukraine, and United States of America. In September 2014, TU1208 has been praised among the running Actions as 'COST Success Story' ('The Cities of Tomorrow: The Challenges of Horizon 2020,' September 17-19, 2014, Torino, IT - A COST strategic workshop on the development and needs of the European cities). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of buried objects

  20. RADAR WARNING SYSTEM,

    DTIC Science & Technology

    RADAR TRACKING, *AIRCRAFT DEFENSE SYSTEMS, RADAR EQUIPMENT, AIR TO AIR, SEARCH RADAR, GUIDED MISSILES, HIGH SPEED BOMBING, EARLY WARNING SYSTEMS, FIRE CONTROL SYSTEM COMPONENTS, AIRCRAFT, TIME, CHINA.

  1. Effect of measurement error on tests of density dependence of catchability for walleyes in northern Wisconsin angling and spearing fisheries

    USGS Publications Warehouse

    Hansen, M.J.; Beard, T.D.; Hewett, S.W.

    2005-01-01

    We sought to determine how much measurement errors affected tests of density dependence of spearing and angling catchability for walleye Sander vitreus by quantifying relationships between spearing and angling catch rates (catch/h) and walleye population density (number/acre) in northern Wisconsin lakes. The mean measurement error of spearing catch rates was 43.5 times greater than the mean measurement error of adult walleye population densities, whereas the mean measurement error of angling catch rates was only 5.6 times greater than the mean measurement error of adult walleye population densities. The bias-corrected estimate of the relationship between spearing catch rate and adult walleye population density was similar to the ordinary-least-squares regression estimate but differed significantly from the geometric mean (GM) functional regression estimate. In contrast, the bias-corrected estimate of the relationship between angling catch rate and total walleye population density was intermediate between ordinary-least-squares and GM functional regression estimates. Catch rates of walleyes in both spearing and angling fisheries were not linearly related to walleye population density, which indicated that catch rates in both fisheries were hyperstable in relation to walleye population density. For both fisheries, GM functional regression overestimated the degree of hyperdepletion in catch rates and ordinary-least-squares regression overestimated the degree of hyperstability in catch rates. However, ordinary-least-squares regression induced significantly less bias in tests of density dependence than GM functional regression, so it may be suitable for testing the degree of density dependence in fisheries for which fish population density is estimated with mark-recapture methods similar to those used in our study. ?? Copyright by the American Fisheries Society 2005.

  2. Estimating 3D variation in active-layer thickness beneath arctic streams using ground-penetrating radar

    USGS Publications Warehouse

    Brosten, T.R.; Bradford, J.H.; McNamara, J.P.; Gooseff, M.N.; Zarnetske, J.P.; Bowden, W.B.; Johnston, M.E.

    2009-01-01

    We acquired three-dimensional (3D) ground-penetrating radar (GPR) data across three stream sites on the North Slope, AK, in August 2005, to investigate the dependence of thaw depth on channel morphology. Data were migrated with mean velocities derived from multi-offset GPR profiles collected across a stream section within each of the 3D survey areas. GPR data interpretations from the alluvial-lined stream site illustrate greater thaw depths beneath riffle and gravel bar features relative to neighboring pool features. The peat-lined stream sites indicate the opposite; greater thaw depths beneath pools and shallower thaw beneath the connecting runs. Results provide detailed 3D geometry of active-layer thaw depths that can support hydrological studies seeking to quantify transport and biogeochemical processes that occur within the hyporheic zone.

  3. Parameters of optical signals registered with the AZT-33IK telescope in active Radar-Progress space experiment

    NASA Astrophysics Data System (ADS)

    Eselevich, Maksim; Khakhinov, Vitaliy; Klunko, Evgeniy

    2016-09-01

    Images of Progress cargo spacecraft (PCS) and areas around them were captured by the AZT-33IK optical telescope (Sayan Observatory of ISTP SB RAS) during sessions of the active Radar-Progress space experiment. We took images of exhaust and fuel jets when propulsion systems worked and after they were cut off, during fuel system purging. In different sessions of the experiment, PCS had different orientations relative to the telescope, thus allowing us to find some parameters of the observed phenomena. These parameters make it possible to determine instants of engine ignitions, to estimate velocities of the jets, and, if necessary, to control the geometry of the space experiment. The paper reports common features of optical signals from jets measured in these experiments.

  4. Research relative to weather radar measurement techniques

    NASA Technical Reports Server (NTRS)

    Smith, Paul L.

    1992-01-01

    This grant provides for some investigations related to weather radar measurement techniques applicable to meteorological radar systems in Thailand. Quality data are needed from those systems to support TRMM and other scientific investigations. Activities carried out during a trip to the radar facilities at Phuket are described.

  5. Recent advances in radar applications to agriculture

    NASA Technical Reports Server (NTRS)

    Morain, S. A.

    1970-01-01

    A series of remote radar sensing studies are summarized. These efforts comprise geoscience interpretations of such complex phenomena as those manifested in agricultural patterns. Considered are basic remote sensing needs in agriculture and the design and implementation of radar keys in the active microwave region as well as fine resolution radar imagery techniques for agriculture determinations and soil mapping.

  6. Optimization of the Dynamic Aperture for SPEAR3 Low-Emittance Upgrade

    SciTech Connect

    Wang, Lanfa; Huang, Xiaobiao; Nosochkov, Yuri; Safranek, James A.; Borland, Michael; /Argonne

    2012-05-30

    A low emittance upgrade is planned for SPEAR3. As the first phase, the emittance is reduced from 10nm to 7nm without additional magnets. A further upgrade with even lower emittance will require a damping wiggler. There is a smaller dynamic aperture for the lower emittance optics due to a stronger nonlinearity. Elegant based Multi-Objective Genetic Algorithm (MOGA) is used to maximize the dynamic aperture. Both the dynamic aperture and beam lifetime are optimized simultaneously. Various configurations of the sextupole magnets have been studied in order to find the best configuration. The betatron tune also can be optimized to minimize resonance effects. The optimized dynamic aperture increases more than 15% from the nominal case and the lifetime increases from 14 hours to 17 hours. It is important that the increase of the dynamic aperture is mainly in the beam injection direction. Therefore the injection efficiency will benefit from this improvement.

  7. Old Wine in New Bottles-The SPEAR Control System Upgrade

    SciTech Connect

    Rarback, Harvey

    1999-10-19

    The control systems for the SPEAR storage ring and injector were designed almost two decades ago and have worked reliably for us. Both systems are heavily dependent on the OpenVMS operating system and CAMAC. The realtime data reside in shared memory on a single computer for each control system. In order to use more modern client tools while preserving our investment in the hardware and software, we have installed an EPICS Portable Channel Access Server (CAS) on the control computers. The CAS will serve the existing realtime data as EPICS Process Variables (PVs) and allow us to use client tools like dm2k and IDL running on other workstations to more easily build new operator interfaces and develop accelerator physics programs. The CAS will also provide the infrastructure to help integrate new hardware controlled by EPICS Input/Output Controllers (IOCs).

  8. Web-based Tools for Educators: Outreach Activities of the Polar Radar for Ice Sheet Measurements (PRISM) Project

    NASA Astrophysics Data System (ADS)

    Braaten, D. A.; Holvoet, J. F.; Gogineni, S.

    2003-12-01

    The Radar Systems and Remote Sensing Laboratory at the University of Kansas (KU) has implemented extensive outreach activities focusing on Polar Regions as part of the Polar Radar for Ice Sheet Measurements (PRISM) project. The PRISM project is developing advanced intelligent remote sensing technology that involves radar systems, an autonomous rover, and communications systems to measure detailed ice sheet characteristics, and to determine bed conditions (frozen or wet) below active ice sheets in both Greenland and Antarctica. These measurements will provide a better understanding of the response of polar ice sheets to global climate change and the resulting impact the ice sheets will have on sea level rise. Many of the research and technological development aspects of the PRISM project, such as robotics, radar systems, climate change and exploration of harsh environments, can kindle an excitement and interest in students about science and technology. These topics form the core of our K-12 education and training outreach initiatives, which are designed to capture the imagination of young students, and prompt them to consider an educational path that will lead them to scientific or engineering careers. The K-12 PRISM outreach initiatives are being developed and implemented in a collaboration with the Advanced Learning Technology Program (ALTec) of the High Plains Regional Technology in Education Consortium (HPR*TEC). ALTec is associated with the KU School of Education, and is a well-established educational research center that develops and hosts web tools to enable teachers nationwide to network, collaborate, and share resources with other teachers. An example of an innovative and successful web interface developed by ALTec is called TrackStar. Teachers can use TrackStar over the Web to develop interactive, resource-based lessons (called tracks) on-line for their students. Once developed, tracks are added to the TrackStar database and can be accessed and modified

  9. COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar": first-year activities and results

    NASA Astrophysics Data System (ADS)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Slob, Evert; Tosti, Fabio

    2014-05-01

    This work aims at presenting the first-year activities and results of COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar". This Action was launched in April 2013 and will last four years. The principal aim of COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of buried objects, shape-reconstruction and estimation of geophysical parameters useful for civil engineering needs; (iv) networking for the design, realization and optimization of innovative GPR equipment; (v) comparing GPR with different NDT techniques, such as ultrasonic, radiographic, liquid-penetrant, magnetic-particle, acoustic-emission and eddy-current testing; (vi) comparing GPR technology and methodology used in civil engineering with those used in other fields; (vii) promotion of a more widespread, advanced and efficient use of GPR in civil engineering; and (viii) organization of a high-level modular training program for GPR European users. Four Working Groups (WGs) carry out the research activities. The first WG

  10. Research relative to weather radar measurement techniques

    NASA Technical Reports Server (NTRS)

    Smith, Paul L.

    1992-01-01

    Research relative to weather radar measurement techniques, which involves some investigations related to measurement techniques applicable to meteorological radar systems in Thailand, is reported. A major part of the activity was devoted to instruction and discussion with Thai radar engineers, technicians, and meteorologists concerning the basic principles of radar meteorology and applications to specific problems, including measurement of rainfall and detection of wind shear/microburst hazards. Weather radar calibration techniques were also considered during this project. Most of the activity took place during two visits to Thailand, in December 1990 and February 1992.

  11. Extended target recognition in cognitive radar networks.

    PubMed

    Wei, Yimin; Meng, Huadong; Liu, Yimin; Wang, Xiqin

    2010-01-01

    We address the problem of adaptive waveform design for extended target recognition in cognitive radar networks. A closed-loop active target recognition radar system is extended to the case of a centralized cognitive radar network, in which a generalized likelihood ratio (GLR) based sequential hypothesis testing (SHT) framework is employed. Using Doppler velocities measured by multiple radars, the target aspect angle for each radar is calculated. The joint probability of each target hypothesis is then updated using observations from different radar line of sights (LOS). Based on these probabilities, a minimum correlation algorithm is proposed to adaptively design the transmit waveform for each radar in an amplitude fluctuation situation. Simulation results demonstrate performance improvements due to the cognitive radar network and adaptive waveform design. Our minimum correlation algorithm outperforms the eigen-waveform solution and other non-cognitive waveform design approaches.

  12. Stanford Synchrotron Radiation Laboratory. Activity report for 1988

    SciTech Connect

    Cantwell, K.

    1996-01-01

    For SSRL operations, 1988 was a year of stark contrasts. The first extended PEP parasitic running since the construction of our two beam lines on that storage ring took place in November and December. Four experiments discussed below, were performed and detailed operational procedures which allowed synchrotron radiation an high energy users to coexist were established. SSRL anticipates that there will be significant amounts of beam time when PEP is run again for high energy physics. On the other hand, activity on SPEAR consisted of brief parasitic running on the VUV lines in December when the ring was operated at 1.85 GeV for colliding beam experiments. There was no dedicated SPEAR running throughout the entire calendar year. This is the first time since dedicated SPEAR operation was initiated in 1980 that there was no such running. The decision was motivated by both cost and performance factors, as discussed in Section 1 of this report. Fortunately, SLAC and SSRL have reached an agreement on SPEAR and PEP dedicated time charges which eliminates the cost volatility which was so important in the cancellation of the June-July dedicated SPEAR run. As discussed in Section 2, the 3 GeV SPEAR injector construction is proceeding on budget and on schedule. The injector will overcome the difficulties associated with the SLC-era constraint of only two injections per day. SSR and SLAC have also embarked on a program to upgrade SPEAR to achieve high reliability and performance. As a consequence, SSRL`s users may anticipate a highly effective SPEAR by 1991, at the latest. At that time, SPEAR is expected to be fully dedicated to synchrotron radiation research and operated by SSRL. Also contained in this report is a discussion of the improvements to SSRL`s experimental facilities and highlights of the experiments of the past year.

  13. Microwave radar oceanographic investigations

    NASA Technical Reports Server (NTRS)

    Jackson, F. C.

    1988-01-01

    The Radar Ocean Wave Spectrometer (ROWS) technique was developed and demonstrated for measuring ocean wave directional spectra from air and space platforms. The measurement technique was well demonstrated with data collected in a number of flight experiments involving wave spectral comparisons with wave buoys and the Surface Contour Radar (SCR). Recent missions include the SIR-B underflight experiment (1984), FASINEX (1986), and LEWEX (1987). ROWS related activity is presently concentrating on using the aircraft instrument for wave-processes investigations and obtaining the necessary support (consensus) for a satellite instrument development program. Prospective platforms include EOS and the Canadian RADARSAT.

  14. Design of an Ultra-Efficient GaN High Power Amplifier for Radar Front-Ends Using Active Harmonic Load-Pull

    NASA Technical Reports Server (NTRS)

    Thrivikraman, Tushar; Hoffman, James

    2012-01-01

    This work presents a new measurement technique, mixed-signal active harmonic load-pull (MSALP) developed by Anterverta-mw in partnership with Maury Microwave, that allows for wide-band ultra-high efficiency amplifiers to be designed using GaN technology. An overview of the theory behind active load-pull is presented and why load-pull is important for high-power device characterization. In addition, an example procedure is presented that outlines a methodology for amplifier design using this measurement system. Lastly, measured results of a 10W GaN amplifier are presented. This work aims to highlight the benefit of using this sophisticated measurement systems for to optimize amplifier design for real radar waveforms that in turn will simplify implementation of space-based radar systems

  15. ERS-1 scatterometer calibration and validation activities at ECMWF. B: From radar backscatter characteristics to wind vector solutions

    NASA Technical Reports Server (NTRS)

    Stoffelen, AD; Anderson, David L. T.; Woiceshyn, Peter M.

    1992-01-01

    Calibration and validation activities for the ERS-1 scatterometer were carried out at ECMWF (European Center for Medium range Weather Forecast) complementary to the 'Haltenbanken' field campaign off the coast of Norway. At a Numerical Weather Prediction (NWP) center a wealth of verifying data is available both in time and space. This data is used to redefine the wind retrieval procedure given the instrumental characteristics. It was found that a maximum likelihood estimation procedure to obtain the coefficients of a reformulated sigma deg to wind relationship should use radar measurements in logarithmic rather than physical space, and use winds as the wind components rather than wind speed and direction. Doing this, a much more accurate transfer function than the one currently operated by ESA was derived. Sigma deg measurement space shows no signature of a separation in an upwind solution cone and a downwind solution cone. As such signature was anticipated in ESA's wind direction ambiguity removal algorithm, reconsideration of the procedure is necessary. Despite the fact that revisions have to be made in the process of wind retrieval; a grid potential is shown for scatterometry in meteorology and climatology.

  16. SPEAR-induced field-aligned irregularities observed from bi-static HF radio scattering in the polar ionosphere

    NASA Astrophysics Data System (ADS)

    Blagoveshchenskaya, N. F.; Borisova, T. D.; Kornienko, V. A.; Kalishin, A. S.; Robinson, T. R.; Yeoman, T. K.; Wright, D. M.; Baddeley, L. J.

    2009-01-01

    Experimental results from SPEAR HF heating experiments in the polar ionosphere are examined. Bi-static scatter measurements of HF diagnostic signals were carried out on the Pori (Finland)-SPEAR-St. Petersburg path at operational frequencies of 11,755 and 15,400 kHz and the London-SPEAR-St. Petersburg path at frequencies of 12,095 and 17,700 kHz, using a Doppler spectral method. The SPEAR HF heating facility generates heater-induced artificial field-aligned small-scale irregularities (AFAIs), which can be detected by HF diagnostic bi-static radio scatter techniques at St. Petersburg at a distance of about 2000 km. In accordance with the Bragg condition, HF bi-static backscatters were sensitive to small-scale irregularities having spatial sizes of the order of 9-13 m across the geomagnetic field line. The properties and behaviour of AFAIs have been considered in the winter and summer seasons under quiet magnetic conditions and under various status of the polar ionosphere (the presence of "thick" and "thin" sporadic Es layers, different structures of the F2 layer). The experimental results obtained have shown that AFAIs can be excited in the F as well as in the E regions of the polar ionosphere. The excitation of a very intense wide-band spectral component with an abrupt increase in the spectral width up to 16-20 Hz has been found in the signals scattered from striations. Along with a wide-band component, a narrow-band spectral component can be also seen in the Doppler sonograms and in the average spectra of the signals scattered from the SPEAR-induced striations. AFAIs were excited even when the HF heater frequency was up to 0.5 MHz larger than the critical frequency. A simulation of the ray geometry for the diagnostic HF radio waves scattered from AFAIs in the polar ionosphere has been made for the geophysical conditions prevailing during experiments carried out in both the winter and summer seasons.

  17. Radar Sounder

    DTIC Science & Technology

    1988-09-01

    over the shorter time period (resulting in a multilook SAR ) with the result that spatial resolution, the usual r~ason for using SAR techniques, degrades...Field - - - ALT 21. Sea Surface Topography - - - SAR , ALT 22. Ocean Waves (sea, swell, surf) V. Good Some V. Good SAR , ALT * with additional lower freq...OLS - Operational Line-scan System radiometer (4-6 GHz?) ALT - Altimeter •* good at low microwave SAR - Synthetic Aperture frequencies Radar + over

  18. Discrimination of Infant Isolation Calls by Female Greater Spear-Nosed Bats, Phyllostomus hastatus

    PubMed Central

    BOHN, KIRSTEN M.; WILKINSON, GERALD S.; MOSS, CYNTHIA F.

    2007-01-01

    In colonial species, recognition of offspring should be under strong selection. For accurate identification to occur offspring must emit individually distinctive signals and parents must be able to discriminate between signals. Female greater spear-nosed bats (Phyllostomus hastatus) roost in stable social groups and use infant vocalizations, termed isolation calls, to locate and identify their young. In this study, we investigate both the production and perception of isolation calls in P. hastatus. First, we measured acoustic features and found that after controlling for ontogenetic effects, sufficient variation exists between pups for isolation calls to function as individual signatures. Moreover, pups from the same social group emit calls with more similar spectral and spectro-temporal features than pups from different social groups, indicating that these features are likely heritable. We used psychoacoustic experiments in the laboratory to determine if adult females could discriminate between calls from pups in the same or different social group. Females discriminated between pups when faced with a template-matching task and their performance was correlated with the salience of spectral and spectro-temporal features. We found no difference in performance when females had to discriminate between pups from the same and different social groups. These results indicate that females should be able to accurately identify their young using isolation calls. PMID:18311319

  19. Implications of the SPEAR FUV Maps on Our Understanding of the ISM

    NASA Astrophysics Data System (ADS)

    Korpela, Eric J.; Sirk, Martin; Edelstein, Jerry; Seon, Kwangil; Min, Kyoung-Wook; Han, Wonyong

    2009-08-01

    The distribution of a low-density transition temperature (104.5-105.5 K) gas in the interstellar medium conveys the character and evolution of diffuse matter in the Galaxy. This difficult to observe component of the ISM emits mainly in the far-ultraviolet (FUV) (912-1800 A˚) band. We describe spectral maps of FUV emission lines from the highly ionized species CIV and OVI likely to be the dominant cooling mechanisms of transition temperature gas in the ISM. The maps were obtained using an orbital spectrometer, SPEAR, that was launched in 2003 and has observed the FUV sky with a spectral resolution of ~550 and an angular resolution of 10'. We compare distribution of flux in these maps with three basic models of the distribution of transition temperature gas. We find that the median distribution of CIV and OVI emission is consistent with the spatial distribution and line ratios expected from a McKee-Ostriker (MO) type model of evaporative interfaces. However, the intensities are a factor of three higher than would be expected at the MO preferred parameters. Some high intensity regions are clearly associated with supernova remnants and superbubble structures. Others may indicate regions where gas is cooling through the transition temperature.

  20. COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar": ongoing research activities and third-year results

    NASA Astrophysics Data System (ADS)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Tosti, Fabio

    2016-04-01

    This work aims at disseminating the ongoing research activities and third-year results of the COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar." About 350 experts are participating to the Action, from 28 COST Countries (Austria, Belgium, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Malta, Macedonia, The Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom), and from Albania, Armenia, Australia, Colombia, Egypt, Hong Kong, Jordan, Israel, Philippines, Russia, Rwanda, Ukraine, and United States of America. In September 2014, TU1208 has been recognised among the running Actions as "COST Success Story" ("The Cities of Tomorrow: The Challenges of Horizon 2020," September 17-19, 2014, Torino, IT - A COST strategic workshop on the development and needs of the European cities). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of

  1. Agricultural and hydrological applications of radar

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T.

    1976-01-01

    Program objectives, covering a wide range of disciplines and activities in radar remote sensing, include radar systems development and analysis, data processing and display, and data interpretation in geology, geography and oceanography. Research was focused on the evaluation of radar remote sensing applications in hydrology and agriculture based on data acquired with the Microwave Active Spectrometer (MAS) system. The title, author(s) and abstract of each of the 62 technical reports generated under this contract are appended.

  2. Modulation error in active-aperture phased-array radar systems

    NASA Astrophysics Data System (ADS)

    Belcher, M. L.; Howard, R. L.; Mitchell, M. A.

    Range sidelobe (RSL) suppression is presently treated in the context of active arrays that are defined by a phased-array antenna, which is driven by either distributed solid-state element-level modules or tube-driven subarray-level transmitters and receivers. An account is given of the basic methodology for achievement of low-RSL performance in active arrays, using modulation-error compensation. Attention is given to the performance limits imposed by modulation-error decorrelation and noise-limited error characterization.

  3. Analysis of radar images of the active volcanic zone at Krafla, Iceland: The effects of look azimuth biasing

    NASA Technical Reports Server (NTRS)

    Garvin, J. B.; Williams, R. S., Jr.

    1989-01-01

    The geomorphic expression of Mid-Ocean-Ridge (MOR) volcanism in a subaerial setting occurs uniquely on Earth in Iceland, and the most recent MOR eruptive activity has been concentrated in the Northeastern Volcanic Zone in an area known as Krafla. Within the Krafla region are many of the key morphologic elements of MOR-related basaltic volcanism, as well as volcanic explosion craters, subglacial lava shields, tectonic fissure swarms known as gjar, and basaltic-andesite flows with well developed ogives (pressure-ridges). The objective was to quantify the degree to which the basic volcanic and structural features can be mapped from directional SAR imagery as a function of the look azimuth. To accomplish this, the current expression of volcanic and tectonic constructs was independently mapped within the Krafla region on the E, W, and N-looking SAR images, as well as from SPOT Panchromatic imagery acquired in 1987. The initial observations of the E, W, and N images indicates that fresh a'a lava surfaces are extremely radar bright (rough at 3 cm to meter scales) independent of look direction; this suggests that these flows do not have strong flow direction related structures at meter and cm scales, which is consistent with typical Icelandic a'a lava surfaces in general. The basic impression from a preliminary analysis of the effects of look azimuth biasing on interpretation of the geology of an active MOR volcanic zone is that up to 30 percent of the diagnostic features can be missed at any given look direction, but that having two orthogonal look direction images is probably sufficient to prevent gross misinterpretation.

  4. Cognitive Nonlinear Radar

    DTIC Science & Technology

    2013-01-01

    Devices and Method for Detecting Emplacement of Improvised Explosive Devices, U. S. Patent 7,680,599, Mar. 16, 2010. 11. Steele, D.; Rotondo, F.; Houck...Patent 7,987,068, Jul. 26, 2011. 9 14. Keller, W. Active Improvised Explosive Device (IED) Electronic Signature Detection , U. S. Patent...operate without interfering with each other. The CNR uses a narrowband, nonlinear radar target detection methodology. This methodology has the advantage

  5. Nordic Snow Radar Experiment

    NASA Astrophysics Data System (ADS)

    Lemmetyinen, Juha; Kontu, Anna; Pulliainen, Jouni; Vehviläinen, Juho; Rautiainen, Kimmo; Wiesmann, Andreas; Mätzler, Christian; Werner, Charles; Rott, Helmut; Nagler, Thomas; Schneebeli, Martin; Proksch, Martin; Schüttemeyer, Dirk; Kern, Michael; Davidson, Malcolm W. J.

    2016-09-01

    The objective of the Nordic Snow Radar Experiment (NoSREx) campaign was to provide a continuous time series of active and passive microwave observations of snow cover at a representative location of the Arctic boreal forest area, covering a whole winter season. The activity was a part of Phase A studies for the ESA Earth Explorer 7 candidate mission CoReH2O (Cold Regions Hydrology High-resolution Observatory). The NoSREx campaign, conducted at the Finnish Meteorological Institute Arctic Research Centre (FMI-ARC) in Sodankylä, Finland, hosted a frequency scanning scatterometer operating at frequencies from X- to Ku-band. The radar observations were complemented by a microwave dual-polarization radiometer system operating from X- to W-bands. In situ measurements consisted of manual snow pit measurements at the main test site as well as extensive automated measurements on snow, ground and meteorological parameters. This study provides a summary of the obtained data, detailing measurement protocols for each microwave instrument and in situ reference data. A first analysis of the microwave signatures against snow parameters is given, also comparing observed radar backscattering and microwave emission to predictions of an active/passive forward model. All data, including the raw data observations, are available for research purposes through the European Space Agency and the Finnish Meteorological Institute. A consolidated dataset of observations, comprising the key microwave and in situ observations, is provided through the ESA campaign data portal to enable easy access to the data.

  6. A handheld device for simultaneous detection of electrical and mechanical cardio-vascular activities with synchronized ECG and CW-Doppler radar.

    PubMed

    Muehlsteff, J; Thijs, J; Pinter, R; Morren, G; Muesch, G

    2007-01-01

    This paper presents a handheld miniaturized sensor embodiment that allows simultaneous measurement of the electrical and related mechanical cardio-vascular activity. Mechanical motion is detected with a continuous wave Doppler radar sensor and interpreted with a synchronously detected ECG. The patient's posture and activity is measured using accelerometers. Challenges of the current technical approach are the positioning of the sensors, the influence of posture and the correct interpretation of the signals. The Doppler signals are compared with phonocardiography measurements, with a focus on the challenges of this technique. There is still research in an improved modeling of the sensor setup and signal interpretation required.

  7. OBSERVATION OF THE FAR-ULTRAVIOLET CONTINUUM BACKGROUND WITH SPEAR/FIMS

    SciTech Connect

    Seon, Kwang-Il; Han, Wonyong; Shinn, Jongho; Kim, Il-Joong; Edelstein, Jerry; Korpela, Eric; Witt, Adolf; Min, Kyoung-Wook; Park, Jae-Woo

    2011-10-01

    We present the general properties of the far-ultraviolet (FUV; 1370-1710 A) continuum background over most of the sky, obtained with the Spectroscopy of Plasma Evolution from Astrophysical Radiation (SPEAR) instrument (also known as FIMS), flown aboard the STSAT-1 satellite mission. We find that the diffuse FUV continuum intensity is well correlated with N{sub HI}, 100 {mu}m, and H{alpha} intensities but anti-correlated with soft X-ray intensity. The correlation of the diffuse background with the direct stellar flux is weaker than the correlation with other parameters. The continuum spectra are relatively flat. However, a weak softening of the FUV spectra toward some sight lines, mostly at high Galactic latitudes, is found not only in direct stellar but also in diffuse background spectra. The diffuse background is relatively softer than the direct stellar spectrum. We also find that the diffuse FUV background averaged over the sky has a bit softer spectrum compared to direct stellar radiation. A map of the ratio of 1370-1520 A to 1560-1710 A band intensity shows that the sky is divided into roughly two parts. However, this map shows a lot of patchy structures on small scales. The spatial variation of the hardness ratio seems to be largely determined by the longitudinal distribution of OB-type stars in the Galactic plane. A correlation of the hardness ratio with the FUV intensity is found at high intensities but an anti-correlation is found at low intensities. We also find evidence that the FUV intensity distribution is log-normal in nature.

  8. An IGBT Driven Slotted Beam Pipe Kicker for SPEAR III Injection

    SciTech Connect

    Cassel, Richard

    2002-08-21

    The SPEAR III injection kicker system is composed of three kicker magnets, K1, K2, and K3. These magnets, along with the power modulators to drive them constitute an injection system which will be used to deflect an incoming electron beam with an energy of 3.3 GeV by an angle of 2.5 mrad for K1 and K3, and 1 mrad for K2. The pulse shape of the magnetic field in the three magnets must be matched in order to preserve a closed orbit. The pulse duration is required to be less than 780 ns, with rise and fall times of less than 375 ns, and a pulse repetition frequency of 10 Hz. The aperture of all three magnets is 60 x 34 mm in an 8 inch vacuum vessel. The magnetic length is 1.2 m for K1 and K3, and 0.6 m for K2 [1]. The magnet design employs a slotted beam pipe which is shorted at one end. A solid state IGBT based, induction type of modulator drives the magnets. Modulators for K1 and K3 consist of eight 4.5 kV, 600 A IGBTs, and eight Finemet magnet cores with four 22.5 Ohm output cables to drive 2381 A into the magnets. The modulator for K2 uses four IGBTs and cores, and 8 output cables to produce a 2619 A pulse. Cables of length greater than one half the pulse width must be used in order to avoid reflections from the shorted magnet. The design charge voltage for the modulators is 20 kV for K1 and K3. This paper describes the magnet and modulator design, as and presents test data from a prototype system.

  9. Development of a practicable non-contact bedside autonomic activation monitoring system using microwave radars and its clinical application in elderly people.

    PubMed

    Matsui, Takemi; Yoshida, Yuto; Kagawa, Masayuki; Kubota, Masayuki; Kurita, Akira

    2013-06-01

    We developed a practicable, non-contact, autonomic activation monitoring system using microwave radars without imposing any stress on monitored individuals. Recently, the rapid increase in the aging population has raised concerns in developed countries. Thus, hospitals and care facilities will need to perform long-term health monitoring of elderly patients. The system allows monitoring of geriatric autonomic dysfunctions caused by chronic diseases, such as diabetes or myocardial infarction (MI), while measuring vital signs in non-contact way. The system measures heart rate variability (HRV) of elderly people in bed using dual, 24-GHz, compact microwave radars attached beneath the bed mattress. HRV parameters (LF, HF, and LF/HF) were determined from the cardiac peak-to-peak intervals, which were detected by radars using the maximum entropy method. We tested the system on 15 elderly people with and without diabetes or MI (72-99 years old) from 7:00 p.m. to 6:00 a.m. at a special nursing home in Tokyo. LF/HF obtained by the system correlated significantly (R = 0.89; p < 0.01) with those obtained by Holter electrocardiography (ECG). Diabetic subjects showed significantly lower LF (radar) than non-diabetic (119.8 ± 57.8 for diabetic, 405.9 ± 112.6 for non-diabetic, p < 0.01). HF (radar) of post-MI subjects was significantly lower than that of non-MI (219.7 ± 131.7 for post-MI and 580.0 ± 654.6 for non-MI, p < 0.05). Previous studies using conventional ECG reveal that diabetic neuropathy decreases LF, and also MI causes parasympathetic attenuation which leads to HF reduction. Our study showed that average SDNN of post-MI patients is smaller than 50 ms which is known to have high mortality. The non-contact autonomic activation monitoring system allows a long-term health management especially during sleeping hours for elderly people at healthcare facilities.

  10. Non-contact detection of myocardium's mechanical activity by ultrawideband RF-radar and interpretation applying electrocardiography.

    PubMed

    Thiel, F; Kreiseler, D; Seifert, F

    2009-11-01

    Electromagnetic waves can propagate through the body and are reflected at interfaces between materials with different dielectric properties. Therefore the reason for using ultrawideband (UWB) radar for probing the human body in the frequency range from 100 MHz up to 10 GHz is obvious and suggests an ability to monitor the motion of organs within the human body as well as obtaining images of internal structures. The specific advantages of UWB sensors are high temporal and spatial resolutions, penetration into object, low integral power, and compatibility with established narrowband systems. The sensitivity to ultralow power signals makes them suitable for human medical applications including mobile and continuous noncontact supervision of vital functions. Since no ionizing radiation is used, and due to the ultralow specific absorption rate applied, UWB techniques permit noninvasive sensing with no potential risks. This research aims at the synergetic use of UWB sounding combined with magnetic resonance imaging (MRI) to gain complementary information for improved functional diagnosis and imaging, especially to accelerate and enhance cardiac MRI by applying UWB radar as a noncontact navigator of myocardial contraction. To this end a sound understanding of how myocardial's mechanic is rendered by reflected and postprocessed UWB radar signals must be achieved. Therefore, we have executed the simultaneous acquisition and evaluation of radar signals with signals from a high-resolution electrocardiogram. The noncontact UWB illumination was done from several radiographic standard positions to monitor selected superficial myocardial areas during the cyclic physiological myocardial deformation in three different respiratory states. From our findings we could conclude that UWB radar can serve as a navigator technique for high and ultrahigh field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it

  11. Non-contact detection of myocardium's mechanical activity by ultrawideband RF-radar and interpretation applying electrocardiography

    NASA Astrophysics Data System (ADS)

    Thiel, F.; Kreiseler, D.; Seifert, F.

    2009-11-01

    Electromagnetic waves can propagate through the body and are reflected at interfaces between materials with different dielectric properties. Therefore the reason for using ultrawideband (UWB) radar for probing the human body in the frequency range from 100 MHz up to 10 GHz is obvious and suggests an ability to monitor the motion of organs within the human body as well as obtaining images of internal structures. The specific advantages of UWB sensors are high temporal and spatial resolutions, penetration into object, low integral power, and compatibility with established narrowband systems. The sensitivity to ultralow power signals makes them suitable for human medical applications including mobile and continuous noncontact supervision of vital functions. Since no ionizing radiation is used, and due to the ultralow specific absorption rate applied, UWB techniques permit noninvasive sensing with no potential risks. This research aims at the synergetic use of UWB sounding combined with magnetic resonance imaging (MRI) to gain complementary information for improved functional diagnosis and imaging, especially to accelerate and enhance cardiac MRI by applying UWB radar as a noncontact navigator of myocardial contraction. To this end a sound understanding of how myocardial's mechanic is rendered by reflected and postprocessed UWB radar signals must be achieved. Therefore, we have executed the simultaneous acquisition and evaluation of radar signals with signals from a high-resolution electrocardiogram. The noncontact UWB illumination was done from several radiographic standard positions to monitor selected superficial myocardial areas during the cyclic physiological myocardial deformation in three different respiratory states. From our findings we could conclude that UWB radar can serve as a navigator technique for high and ultrahigh field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it

  12. Radar and Lidar Radar DEM

    NASA Technical Reports Server (NTRS)

    Liskovich, Diana; Simard, Marc

    2011-01-01

    Using radar and lidar data, the aim is to improve 3D rendering of terrain, including digital elevation models (DEM) and estimates of vegetation height and biomass in a variety of forest types and terrains. The 3D mapping of vegetation structure and the analysis are useful to determine the role of forest in climate change (carbon cycle), in providing habitat and as a provider of socio-economic services. This in turn will lead to potential for development of more effective land-use management. The first part of the project was to characterize the Shuttle Radar Topography Mission DEM error with respect to ICESat/GLAS point estimates of elevation. We investigated potential trends with latitude, canopy height, signal to noise ratio (SNR), number of LiDAR waveform peaks, and maximum peak width. Scatter plots were produced for each variable and were fitted with 1st and 2nd degree polynomials. Higher order trends were visually inspected through filtering with a mean and median filter. We also assessed trends in the DEM error variance. Finally, a map showing how DEM error was geographically distributed globally was created.

  13. New law enforcement applications of millimeter-wave radar

    NASA Astrophysics Data System (ADS)

    Currie, Nicholas C.; Ferris, David D., Jr.; McMillan, Robert W.; Wicks, Michael C.

    1997-06-01

    Recent advances in millimeter-wave (MMW) radar technologies provide new applications for law enforcement use over-and- above the venerable speed timing radar. These applications include the potential to detect weapons under clothing and to conduct surveillance through walls. Concealed Weapon Detection and covert surveillance are of high interest to both the Department of Defense in support of Small Unit Operations and the Justice Department for civilian law enforcement applications. MMW sensors are under development which should provide the needed capabilities including radiometric sensors at 95 GHz, active 95 GHz real aperture radars, active focal plane array (FPA) radars, and holographic radars. Radiometric sensors include 2D FPA systems, 1D FPA, scanned systems, and single element scanned sensors. Active FPA radars include illuminated radiometric systems and coherent radar systems. Real aperture MMW radar systems include raster scanned and conical scanned sensors. Holographic systems ruse mechanical scanners to collect coherent data over a significant solid angular sector.

  14. Comet radar explorer

    NASA Astrophysics Data System (ADS)

    Farnham, Tony; Asphaug, Erik; Barucci, Antonella; Belton, Mike; Bockelee-Morvan, Dominique; Brownlee, Donald; Capria, Maria Teresa; Carter, Lynn; Chesley, Steve; Farnham, Tony; Gaskell, Robert; Gim, Young; Heggy, Essam; Herique, Alain; Klaasen, Ken; Kofman, Wlodek; Kreslavsky, Misha; Lisse, Casey; Orosei, Roberto; Plaut, Jeff; Scheeres, Dan

    The Comet Radar Explorer (CORE) is designed to perform a comprehensive and detailed exploration of the interior, surface, and inner coma structures of a scientifically impor-tant Jupiter family comet. These structures will be used to investigate the origins of cometary nuclei, their physical and geological evolution, and the mechanisms driving their spectacular activity. CORE is a high heritage spacecraft, injected by solar electric propulsion into orbit around a comet. It is capable of coherent deep radar imaging at decameter wavelengths, high resolution stereo color imaging, and near-IR imaging spectroscopy. Its primary objective is to obtain a high-resolution map of the interior structure of a comet nucleus at a resolution of ¿100 elements across the diameter. This structure shall be related to the surface geology and morphology, and to the structural details of the coma proximal to the nucleus. This is an ideal complement to the science from recent comet missions, providing insight into how comets work. Knowing the structure of the interior of a comet-what's inside-and how cometary activity works, is required before we can understand the requirements for a cryogenic sample return mission. But more than that, CORE is fundamental to understanding the origin of comets and their evolution in time. The mission is made feasible at low cost by the use of now-standard MARSIS-SHARAD reflec-tion radar imaging hardware and data processing, together with proven flight heritage of solar electric propulsion. Radar flight heritage has been demonstrated by the MARSIS radar on Mars Express (Picardi et al., Science 2005; Plaut et al., Science 2007), the SHARAD radar onboard the Mars Reconnaissance Orbiter (Seu et al., JGR 2007), and the LRS radar onboard Kaguya (Ono et al, EPS 2007). These instruments have discovered detailed subsurface structure to depths of several kilometers in a variety of terrains on Mars and the Moon. A reflection radar deployed in orbit about a comet

  15. Radar gun hazards

    SciTech Connect

    Not Available

    1991-12-20

    Radar guns - hand-held units used by the law to nail speeders - have been in use since the early '60s. Now they've been accused of causing cancer. Police officers in several states have so far filed eight suits against the manufacturer, claiming that they have contracted rare forms of cancer, such as of the eyelid and the testicle, from frequent proximity to the devices. Spurred by concerns expressed by police groups, researchers at the Rochester Institute of Technology are conducting what they believe to be the first research of its kind in the nation. Last month psychologist John Violanti, an expert in policy psychology and health, sent out a one-page survey to 6,000 active and retired police officers in New York State, asking them about their health and their use of radar guns. Violanti says melanoma, leukemia, and lymph node cancer may be linked to these as well as other electromagnetic devices. The Food and Drug Administration earlier this year issued a warning about radar guns, telling users not to operate them closer than 6 inches from the body. But this may not be a sufficient safeguard since the instruments can give off crisscrossing wave emissions within a police vehicle. The survey will be used to help determine if it would be safer to mount the guns, which are currently either hand-held or mounted on dashboards, outside troopers' cars.

  16. Inter-seasonal surface deformations of an active rock glacier imaged with radar and lidar remote sensing; Turtmann valley, Switzerland

    NASA Astrophysics Data System (ADS)

    Kos, Andrew; Buchli, Thomas; Strozzi, Tazio; Springman, Sarah

    2013-04-01

    Inter-seasonal changes in surface deformation were imaged using a portable radar interferometer and terrestrial laser scanner during a series of three campaigns that took place in autumn 2011, summer 2012 and autumn 2012 on a rock glacier located in the Turtmann valley, Switzerland. Satellite radar interferometry (ERS 1 & 2, CosmoSkymed) indicate that accelerated downslope movement of the rock glacier commenced during the 1990s. Due to signal decorrelation associated with the satellite repeat pass time interval, continuous ground-based radar interferometry measurements were undertaken. Results show that the rock glacier accelerated significantly in Summer (Vmax = 6.0cm/25hrs), probably in response to the condition of the subsurface hydrology (e.g. post-peak spring snow melt and/or infiltration of rainfall). In autumn, the displacement velocity was reduced (Vmax = 2.0cm/25hrs). A one year surface difference of the glacier topography, derived from terrestrial laser scanning, provided insight into the rock glacier kinematics. Ongoing research is aimed at integrating surface displacement results with an extensive borehole monitoring system consisting of inclinometers and temperature sensors.

  17. Streak-Camera Measurements with High Currents in PEP-II and Variable Optics in SPEAR3

    SciTech Connect

    Cheng, Weixeng; Fisher, Alan, a Corbett, Jeff; /SLAC

    2008-06-05

    A dual-axis, synchroscan streak camera was used to measure longitudinal bunch profiles in three storage rings at SLAC: the PEP-II low- and high-energy rings, and SPEAR3. At high currents, both PEP rings exhibit a transient synchronous-phase shift along the bunch train due to RF-cavity beam loading. Bunch length and profile asymmetry were measured along the train for a range of beam currents. To avoid the noise inherent in a dual-axis sweep, we accumulated single-axis synchroscan images while applying a 50-ns gate to the microchannel plate. To improve the extinction ratio, an upstream mirror pivoting at 1 kHz was synchronized with the 2kHz MCP gate to deflect light from other bunches off the photocathode. Bunch length was also measured on the HER as a function of beam energy. For SPEAR3 we measured bunch length as a function of single-bunch current for several lattices: achromatic, low-emittance and low momentum compaction. In the first two cases, resistive and reactive impedance components can be extracted from the longitudinal bunch profiles. In the low-alpha configurations, we observed natural bunch lengths approaching the camera resolution, requiring special care to remove instrumental effects, and saw evidence of periodic bursting.

  18. Ground Penetrating Radar Images of Tephra Deposits Within the Active Crater and on the Crater Rim of Irazú Volcano, Costa Rica

    NASA Astrophysics Data System (ADS)

    Mora, R.; Kruse, S.; Alvarado, G.; Ramirez, C.

    2006-12-01

    Ground penetrating radar (GPR) is a proven tool in a variety of volcanic settings, and offers the promise of imaging strata inaccessible to outcrops or trenching. Here we examine the imaging capabilities of GPR in the complex sequence of surge and fall deposits from the 1963-1963 eruption sequence of Irazú volcano, Costa Rica. We compare radar profiles within the active crater and on the crater rim with field observations and the generalized stratigraphic section of this eruption sequence described by Alvarado (1993). The Irazú GPR transects on the active crater, collected with 100 and 200 MHz antennas, show a strong reflector that correlates well with the base of the 1963 tephra deposits. The spectral characteristics of the traces from deposits within the active crater suggest the presence of laminated zones in which layers are too fine to be resolved individually. The profiles on the crater rim illuminate changing bed thicknesses as a function of distance from the vent, as well as the patterns of post-depositional sediment transport. The diffractions associated with volcanic blocks indicate many blocks are associated with sag features in which adjacent strata are depressed more than the height of the block.

  19. Combining Satellite and Ground-Based Radar Interferometry Data to Measure Surface Deformation Associated with EGS Pumping Activities at Newberry Crater, OR Geothermal Site

    NASA Astrophysics Data System (ADS)

    Vincent, P.; Cladouhos, T. T.; Schultz, A.; Rose, K.; Urquhart, S.

    2013-12-01

    TerraSAR-X (TSX) satellite data are combined with data collected using a ground-based real aperture radar interferometer (GAMMA Remote Sensing AG Portable Radar Interferometer-2, GPRI2) to remotely image surface deformation arising from enhanced geothermal system (EGS) pumping activity at the geothermal site located off the western flank of Newberry Crater, OR. Due to the heavily forested area impeding the utility of interferometric measurements at X-band (TSX) and Ku-band (GPRI2) wavelengths, 100 aluminum radar corner reflectors (CRs) were fabricated and installed in pairs approximately 5-8 meters above the ground in 50 large trees for optimal visibility and wind stability. One CR in each pair was aimed up at the ascending orbit track look direction for TSX, and the other was simultaneously aimed at the descending orbit track look direction for TSX and to Paulina Peak 6 km to the southwest for line-of-sight to the GPRI2 antenna position. The combination of 11-day repeat orbit acquisitions from a near vertical look direction from TSX with on-demand (up to daily) acquisitions from a near horizontal look direction from the GPRI2 instrument allows for full 3D displacement vector determination for each target imaged. Standard and point-target processing techniques are used to maximize the utility of the data collected and the transient nature of the pumping activities and resulting surface deformation signals demand this high level of spatial-temporal sampling. Preliminary data quality and deformation signal results will be presented and put in context with well-log data such as pressure, volume and flow rate, as well as data from microseismic array, MT, and gravity surveys.

  20. Incidence angle normalization of radar backscatter data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NASA’s Soil Moisture Passive Active (SMAP) satellite (~2014) will include a radar system that will provide L-band multi-polarization backscatter at a constant incidence angle of 40º. During the pre-launch phase of the project there is a need for observations that will support the radar-based soil mo...

  1. Frequency Diversity for Improving Synthetic Aperture Radar Imaging

    DTIC Science & Technology

    2009-03-01

    xiii List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvi I. Introduction ...Improving Synthetic Aperture Radar Imaging I. Introduction 1.1 Research Motivation Synthetic aperture radar (SAR) is an active radio frequency (RF) imaging...PFA) begins with introduction of the linear frequency modulated (LFM) waveform. LFM is the most common waveform used in general radar applications [25

  2. Sexual Satisfaction, Performance, and Partner Response Following Voluntary Medical Male Circumcision in Zambia: The Spear and Shield Project

    PubMed Central

    Zulu, Robert; Jones, Deborah; Chitalu, Ndashi; Cook, Ryan; Weiss, Stephen

    2015-01-01

    Background: Voluntary medical male circumcision (VMMC) is an important HIV prevention strategy, particularly in regions with high HIV incidence and low rates of male circumcision. However, 88% of the Zambian male population remain uncircumcised, and of these 80% of men surveyed expressed little interest in undergoing VMMC. Methods: The Spear and Shield study (consisting of 4 weekly, 90-minute sexual risk reduction/VMMC promotion sessions) recruited and enrolled men (N = 800) who self-identified as at risk of HIV by seeking HIV testing and counseling at community health centers. Eligible men tested HIV-negative, were uncircumcised, and expressed no interest in VMMC. Participants were encouraged (but not required) to invite their female partners (N = 668) to participate in the program in a gender-concordant intervention matched to their partners’. Men completed assessments at baseline, post-intervention (about 2 months after baseline), and 6 and 12 months post-intervention; women completed assessments at baseline and post-intervention. For those men who underwent VMMC and for their partners, an additional assessment was conducted 3 months following the VMMC. The ancillary analysis in this article compared the pre- and post-VMMC responses of the 257 Zambian men who underwent circumcision during or following study participation, using growth curve analyses, as well as of the 159 female partners. Results: Men were satisfied overall with the procedure (mean satisfaction score, 8.4 out of 10), and nearly all men (96%) and women (94%) stated they would recommend VMMC to others. Approximately half of the men reported an increase or no change in erections, orgasms, and time to achieve orgasms from pre-VMMC, while one-third indicated fewer erections and orgasms and decreased time to achieve orgasms post-VMMC. Nearly half (42%) of the men, and a greater proportion (63%) of the female partners, said their sexual pleasure increased while 22% of the men reported less

  3. The proposed flatland radar

    NASA Technical Reports Server (NTRS)

    Green, J. L.; Gage, K. S.; Vanzandt, T. E.; Nastrom, G. D.

    1986-01-01

    A flexible very high frequency (VHF) stratosphere-troposphere (ST) radar configured for meteorological research is to be constructed near Urbana, Illinois. Measurement of small vertical velocities associated with synoptic-scale meteorology can be performed. A large Doppler microwave radar (CHILL) is located a few km from the site of the proposed ST radar. Since the microwave radar can measure the location and velocity of hydrometeors and the VHF ST radar can measure clear (or cloudy) air velocities, simultaneous observations by these two radars of stratiform or convective weather systems would provide valuable meteorological information.

  4. Radar Image, Hokkaido, Japan

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The southeast part of the island of Hokkaido, Japan, is an area dominated by volcanoes and volcanic caldera. The active Usu Volcano is at the lower right edge of the circular Lake Toya-Ko and near the center of the image. The prominent cone above and to the left of the lake is Yotei Volcano with its summit crater. The city of Sapporo lies at the base of the mountains at the top of the image and the town of Yoichi -- the hometown of SRTM astronaut Mamoru Mohri -- is at the upper left edge. The bay of Uchiura-Wan takes up the lower center of the image. In this image, color represents elevation, from blue at the lowest elevations to white at the highest. The radar image has been overlaid to provide more details of the terrain. Due to a processing problem, an island in the center of this crater lake is missing and will be properly placed when further SRTM swaths are processed. The horizontal banding in this image is a processing artifact that will be removed when the navigation information collected by SRTM is fully calibrated. This image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 100 by 150 kilometers

  5. The Spaceborne Imaging Radar-C, X-Band Synthetic Aperture radar (SIR-C/X-SAR) Mission Overview

    NASA Technical Reports Server (NTRS)

    Evans, D. L.; Stofan, E. R.; Farr, T.; Plaut, J.; vanZyl, J.; Kobrick, M.; Holt, B.; Way, J. B.; Ottl, H.; Schmullius, C.; Nithack, J.; Calamia, M.

    1994-01-01

    The Spaceborne Imaging Radar-C, X-Band Synthetic Aperture Radar (SIR-C/X-SAR) was launched on space shuttle Endeavour at 7:05 AM EDT, Saturday, April 9, 1994. Soon after launch, the radars were activated and began around the clock operations which lasted for the next 10 days.

  6. Space Radar Image of Long Island Optical/Radar

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This pair of images of the Long Island, New York region is a comparison of an optical photograph (top) and a radar image (bottom), both taken in darkness in April 1994. The photograph at the top was taken by the Endeavour astronauts at about 3 a.m. Eastern time on April 20, 1994. The image at the bottom was acquired at about the same time four days earlier on April 16,1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) system aboard the space shuttle Endeavour. Both images show an area approximately 100 kilometers by 40 kilometers (62 miles by 25 miles) that is centered at 40.7 degrees North latitude and 73.5 degrees West longitude. North is toward the upper right. The optical image is dominated by city lights, which are particularly bright in the densely developed urban areas of New York City located on the left half of the photo. The brightest white zones appear on the island of Manhattan in the left center, and Central Park can be seen as a darker area in the middle of Manhattan. To the northeast (right) of the city, suburban Long Island appears as a less densely illuminated area, with the brightest zones occurring along major transportation and development corridors. Since radar is an active sensing system that provides its own illumination, the radar image shows a great amount of surface detail, despite the night-time acquisition. The colors in the radar image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted and vertically received); blue represents the C-band (horizontally transmitted and vertically received). In this image, the water surface - the Atlantic Ocean along the bottom edge and Long Island Sound shown at the top edge - appears red because small waves at the surface strongly reflect the horizontally transmitted and received L-band radar signal. Networks of highways and railroad lines are clearly

  7. RADAR "SAIL" satellite concept

    NASA Astrophysics Data System (ADS)

    Aguttes, Jean Paul; Sombrin, Jacques; Conde, Eric

    1996-11-01

    The Radar SAIL concept is based on the use of a rectangular antenna lying in the dawn-dusk orbital plane with the length (along speed vector) smaller than the height. Such geometry makes it possible to place the solar cells on the back of the antenna, to use gravity gradient stabilisation, and to implement multipath-free GPS interferometric measurement of the antenna deformation thus allowing structural relaxation. Less obviously, the geometry favours the RADAR design too, by allowing grating lobes and therefore a lower density of built-in electronic in the active antenna. The antenna can be thin and packed for launch inside a cylinder-shaped bus having pyrotechnic doors for the antenna deployement and bearing the rest of the payload and the service equipment. With respect to a standard design of performant missions, cost savings come from the bus, whose functions (AOCS, power supply) are simplified, from the launch since the mass budget and the stowing configuration become compatible with medium size rockets (LLV2/3, DELTA-LITE, LM-4.), and from the active antenna built-in electronics. The RADAR SAIL concept is all the more cost effective when the mission requires a large, high and short antenna, i.e. high resolution (<5m), low frequency band (L or S or even P), high revisiting, multiple frequencies. Mission implementation and funding can be favored by the new capability to share the satellite between autonomous regional operators. Combined with ground DBF (digital beam forming) technique, the concept allows extremely simple and low cost missions providing a fixed wide swath (10 to 15 m resolution within 500km to 1000 km swath) for systematic surveillance or monitoring.

  8. Explicit characteristics of evolutionary-type plasma bubbles observed from Equatorial Atmosphere Radar during the low to moderate solar activity years 2010-2012

    NASA Astrophysics Data System (ADS)

    Ajith, K. K.; Ram, S. Tulasi; Yamamoto, M.; Yokoyama, T.; Gowtam, V. Sai; Otsuka, Y.; Tsugawa, T.; Niranjan, K.

    2015-02-01

    Using the fan sector backscatter maps of 47 MHz Equatorial Atmosphere Radar (EAR) at Kototabang (0.2°S geographic latitude, 100.3°E geographic longitude, and 10.4°S geomagnetic latitude), Indonesia, the spatial and temporal evolution of equatorial plasma bubbles (EPBs) were examined to classify the evolutionary-type EPBs from those which formed elsewhere and drifted into the field of view of radar. A total of 535 EPBs were observed during the low to moderate solar activity years 2010-2012, out of which about 210 (~39%) are of evolving type and the remaining 325 (~61%) are drifting-in EPBs. In general, both the evolving-type and drifting-in EPBs exhibit predominance during the postsunset hours of equinoxes and December solstices. Interestingly, a large number of EPBs were found to develop even a few minutes prior to the apex sunset during equinoxes. Further, the occurrence of evolving-type EPBs exhibits a clear secondary peak around midnight (2300-0100 LT), primarily, due to higher rate of occurrence during the postmidnight hours of June solstices. A significant number (~33%) of postmidnight EPBs generated during June solstices did not exhibited any clear zonal drift, while about 14% of EPBs drifted westward. Also, the westward drifting EPBs are confined only to June solstices. The responsible mechanisms for the genesis of fresh EPBs during postmidnight hours were discussed in light of equatorward meridional winds in the presence of weak westward electric fields.

  9. Weather Radar Technology Development

    DTIC Science & Technology

    1990-08-15

    uelocitV WMs ) data processing systems such as NEXRAD to have a reliable technique for removing ambiguities due to velocity aliasing. Performance of many...intended for automated implementation on radar systems such as the NEXt generation weather RADar ( NEXRAD ) system. Several research areas were addressed...with Doppler radar will soon be realized with the deployment of the NEXRAD radar systems. Some of these large scale storms can have devastating wind

  10. Radar: Human Safety Net

    ERIC Educational Resources Information Center

    Ritz, John M.

    2016-01-01

    Radar is a technology that can be used to detect distant objects not visible to the human eye. A predecessor of radar, called the telemobiloscope, was first used to detect ships in the fog in 1904 off the German coast. Many scientists have worked on the development and refinement of radar (Hertz with electromagnetic waves; Popov with determining…

  11. Lunar radar backscatter studies

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.

    1979-01-01

    The lunar surface material in the Plato area is characterized using Earth based visual, infrared, and radar signatures. Radar scattering in the lunar regolith with an existing optical scattering computer program is modeled. Mapping with 1 to 2 km resolution of the Moon using a 70 cm Arecibo radar is presented.

  12. PERFORMANCE OF THE LEAD/LIQUID ARGON SHOWER COUNTER SYSTEM OF THE MARK II DETECTOR AT SPEAR

    SciTech Connect

    Abrams, G S; Blocker, C A; Briggs, D D; Carithers, W C; Dieterle, W E; Eaton, M W; Lankford, A J; Pang, C Y; Vella, E N; Breidenbach, M; Dorfan, J M; Hanson, G; Hitlin, D G; Jenni, P; Luth, V

    1980-05-01

    The shower counter system of the SLAC-LBL Mark II detector is a large lead/liquid argon system of the type pioneered by Willis and Radekal; however, it differs in most details and is much larger than other such detectors currently in operation, It contains, for example, 8000 liters of liquid argon and 3000 channels of low noise electronics, which is about eight times the size of the system of Willis et al. in the CERN ISR. This paper reports, with little reference to design, on the operation and performance of the Mark II system during approximately a year and a half of operation at the Stanford Linear Accelerator Center's e{sup +}-e{sup -} facility, SPEAR. The design and construction of the system have previously been described and a detailed discussion of all aspects -- design, construction, operation, and performance -- is in preparation.

  13. "Tip of the spear" physical therapy during a 6-month deployment to the Persian Gulf: a preliminary report.

    PubMed

    Ziemke, G W; Koffman, R L; Wood, D P

    2001-06-01

    When a U.S. Navy aircraft carrier battle group deploys overseas, the ship's medical department is responsible for more than 10,000 personnel and their numerous musculoskeletal injuries. This paper reviews the effectiveness of having a U.S. Navy physical therapist and physical therapy technician onboard the USS Carl Vinson during its most recent deployment to the Persian Gulf. Physical therapy had 3,373 patient visits during the ship's 1998-1999 Western Pacific deployment. Having physical therapy personnel onboard resulted in fewer patient visits to sick call for musculoskeletal problems and fewer evacuations compared with other similar carrier deployments. Providing physical therapy at the "tip of the spear" is an effective, beneficial, and cost-saving landmark improvement in providing quality medical care to the fleet. The lessons learned from this experience will assist in clarifying the role of physical therapy in future military support operations and sustained deployments.

  14. Detection and Classification of Finer-Grained Human Activities Based on Stepped-Frequency Continuous-Wave Through-Wall Radar

    PubMed Central

    Qi, Fugui; Liang, Fulai; Lv, Hao; Li, Chuantao; Chen, Fuming; Wang, Jianqi

    2016-01-01

    The through-wall detection and classification of human activities are critical for anti-terrorism, security, and disaster rescue operations. An effective through-wall detection and classification technology is proposed for finer-grained human activities such as piaffe, picking up an object, waving, jumping, standing with random micro-shakes, and breathing while sitting. A stepped-frequency continuous wave (SFCW) bio-radar sensor is first used to conduct through-wall detection of finer-grained human activities; Then, a comprehensive range accumulation time-frequency transform (CRATFR) based on inverse weight coefficients is proposed, which aims to strengthen the micro-Doppler features of finer activity signals. Finally, in combination with the effective eigenvalues extracted from the CRATFR spectrum, an optimal self-adaption support vector machine (OS-SVM) based on prior human position information is introduced to classify different finer-grained activities. At a fixed position (3 m) behind a wall, the classification accuracies of six activities performed by eight individuals were 98.78% and 93.23%, respectively, for the two scenarios defined in this paper. In the position-changing experiment, an average classification accuracy of 86.67% was obtained for five finer-grained activities (excluding breathing) of eight individuals within 6 m behind the wall for the most practical scenario, a significant improvement over the 79% accuracy of the current method. PMID:27314362

  15. Doppler sodar and radar wind-profiler observations of gravity-wave activity associated with a gravity current

    SciTech Connect

    Ralph, F.M.; Venkateswaran, S.V. ); Mazaudier, C. ); Crochet, M. )

    1993-02-01

    Observations from two Doppler sodars and a radar wind profiler have been used in conjunction with data from a rawinsonde station and a mesoscale surface observation network to conduct a case study of a gravity current entering into an environment containing a nocturnal inversion and an elevated neutral layer. On the basis of synoptic and mesoscale analyses, it is concluded that the gravity current might have originated either as a scale-contracted cold front or as a gust front resulting from thunderstorm outflows observed very near the leading edge of a cold front. Despite this ambiguity, the detailed vertical structure of the gravity current itself is well resolved from the data. Moreover, the vertical velocity measurements provided by the sodars and the radar wind profiler at high time resolution have given unique information about the height structure of gravity waves excited by the gravity current. Although only wave periods, and not phase speeds or wavelengths, are directly measured, it is possible to make reasonable inferences about wave excitation mechanisms and about the influence and control of ambient stratification on wave-field characteristics. Both Kelvin-Helmholtz waves generated in the regions of high wind shear found in association with the gravity current and lee-type waves forced by the gravity current acting as an obstacle to opposing prefrontal flow are identified. It is also found that the propagation speed of the gravity current and the relative depths of the prefrontal inversion and the postfrontal cold air were not favorable for the formation of either internal bores or solitary waves at the time of day at which the gravity current was being observed. 42 refs., 18 figs., 1 tab.

  16. Radar stage uncertainty

    USGS Publications Warehouse

    Fulford, J.M.; Davies, W.J.

    2005-01-01

    The U.S. Geological Survey is investigating the performance of radars used for stage (or water-level) measurement. This paper presents a comparison of estimated uncertainties and data for radar water-level measurements with float, bubbler, and wire weight water-level measurements. The radar sensor was also temperature-tested in a laboratory. The uncertainty estimates indicate that radar measurements are more accurate than uncorrected pressure sensors at higher water stages, but are less accurate than pressure sensors at low stages. Field data at two sites indicate that radar sensors may have a small negative bias. Comparison of field radar measurements with wire weight measurements found that the radar tends to measure slightly lower values as stage increases. Copyright ASCE 2005.

  17. Detection of Marine Radar Targets

    NASA Astrophysics Data System (ADS)

    Briggs, John N.

    A radar must detect targets before it can display them. Yet manufacturers' data sheets rarely tell us what the products will detect at what range. Many of the bigger radars are Type Approved so we consult the relevant IMO performance standard A 477 (XII). Paraphrasing Section 3.1 of the draft forthcoming revision (NAV 41/6): under normal propagation conditions with the scanner at height of 15 m, in the absence of clutter, the radar is required to give clear indication of an object such as a navigational buoy having a radar cross section area (RCS) of 10 m2 at 2 n.m. and, as examples, coastlines whose ground rises to 60/6 m at ranges of 20/7 n.m., a ship of 5000 tons at any aspect at 7 n.m. and a small vessel 10 m long at 3 n.m.This helps, but suppose we must pick up a 5 m2 buoy at g km? What happens in clutter? Should we prefer S- or X-band? To answer such questions we use equations which define the performance of surveillance radars, but the textbooks and specialist papers containing them often generalize with aeronautical and defence topics, making life difficult for the nonspecialist.This paper attempts a concise and self-contained engineering account of all main factors affecting detection of passive and active targets on civil marine and vessel traffic service (VTS) radars. We develop a set of equations for X- and S-band (3 and 10 cm, centred on 9400 and 3000 MHz respectively), suited for spreadsheet calculation.Sufficient theory is sketched in to indicate where results should be valid. Some simplifications of conventional treatments have been identified.

  18. Airborne Differential Doppler Weather Radar

    NASA Technical Reports Server (NTRS)

    Meneghini, R.; Bidwell, S.; Liao, L.; Rincon, R.; Heymsfield, G.; Hildebrand, Peter H. (Technical Monitor)

    2001-01-01

    The Precipitation Radar aboard the Tropical Rain Measuring Mission (TRMM) Satellite has shown the potential for spaceborne sensing of snow and rain by means of an incoherent pulsed radar operating at 13.8 GHz. The primary advantage of radar relative to passive instruments arises from the fact that the radar can image the 3-dimensional structure of storms. As a consequence, the radar data can be used to determine the vertical rain structure, rain type (convective/stratiform) effective storm height, and location of the melting layer. The radar, moreover, can be used to detect snow and improve the estimation of rain rate over land. To move toward spaceborne weather radars that can be deployed routinely as part of an instrument set consisting of passive and active sensors will require the development of less expensive, lighter-weight radars that consume less power. At the same time, the addition of a second frequency and an upgrade to Doppler capability are features that are needed to retrieve information on the characteristics of the drop size distribution, vertical air motion and storm dynamics. One approach to the problem is to use a single broad-band transmitter-receiver and antenna where two narrow-band frequencies are spaced apart by 5% to 10% of the center frequency. Use of Ka-band frequencies (26.5 GHz - 40 GHz) affords two advantages: adequate spatial resolution can be attained with a relatively small antenna and the differential reflectivity and mean Doppler signals are directly related to the median mass diameter of the snow and raindrop size distributions. The differential mean Doppler signal has the additional property that this quantity depends only on that part of the radial speed of the hydrometeors that is drop-size dependent. In principle, the mean and differential mean Doppler from a near-nadir viewing radar can be used to retrieve vertical air motion as well as the total mean radial velocity. In the paper, we present theoretical calculations for the

  19. 2. VIEW SOUTHWEST, prime search radar tower, height finder radar ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW SOUTHWEST, prime search radar tower, height finder radar towards, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  20. Using ground-penetrating radar, topography and classification of vegetation to model the sediment and active layer thickness in a periglacial lake catchment, western Greenland

    NASA Astrophysics Data System (ADS)

    Petrone, Johannes; Sohlenius, Gustav; Johansson, Emma; Lindborg, Tobias; Näslund, Jens-Ove; Strömgren, Mårten; Brydsten, Lars

    2016-11-01

    The geometries of a catchment constitute the basis for distributed physically based numerical modeling of different geoscientific disciplines. In this paper results from ground-penetrating radar (GPR) measurements, in terms of a 3-D model of total sediment thickness and active layer thickness in a periglacial catchment in western Greenland, are presented. Using the topography, the thickness and distribution of sediments are calculated. Vegetation classification and GPR measurements are used to scale active layer thickness from local measurements to catchment-scale models. Annual maximum active layer thickness varies from 0.3 m in wetlands to 2.0 m in barren areas and areas of exposed bedrock. Maximum sediment thickness is estimated to be 12.3 m in the major valleys of the catchment. A method to correlate surface vegetation with active layer thickness is also presented. By using relatively simple methods, such as probing and vegetation classification, it is possible to upscale local point measurements to catchment-scale models, in areas where the upper subsurface is relatively homogeneous. The resulting spatial model of active layer thickness can be used in combination with the sediment model as a geometrical input to further studies of subsurface mass transport and hydrological flow paths in the periglacial catchment through numerical modeling. The data set is available for all users via the PANGAEA database, doi:10.1594/PANGAEA.845258.

  1. Analysis of synthetic aperture radar imagery

    NASA Technical Reports Server (NTRS)

    Blanchard, B. J. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. Average radar response for L-band like polarized system appeared to be related to the watershed runoff coefficients when the viewing angle was approximately 42 deg off nadir. Four requirements for radar systems used to verify applications of active microwave for water resources were identified: (1) first generation digital data will be required; (2) radar should be calibrated both internally and externally; (3) new systems should avoid radom use; and (4) images should be geometrically rectified prior to delivery to the user.

  2. Classification and modeling of human activities using empirical mode decomposition with S-band and millimeter-wave micro-Doppler radars

    NASA Astrophysics Data System (ADS)

    Fairchild, Dustin P.; Narayanan, Ram M.

    2012-06-01

    The ability to identify human movements can be an important tool in many different applications such as surveillance, military combat situations, search and rescue operations, and patient monitoring in hospitals. This information can provide soldiers, security personnel, and search and rescue workers with critical knowledge that can be used to potentially save lives and/or avoid a dangerous situation. Most research involving human activity recognition is focused on using the Short-Time Fourier Transform (STFT) as a method of analyzing the micro-Doppler signatures. Because of the time-frequency resolution limitations of the STFT and because Fourier transform-based methods are not well-suited for use with non-stationary and nonlinear signals, we have chosen a different approach. Empirical Mode Decomposition (EMD) has been shown to be a valuable time-frequency method for processing non-stationary and nonlinear data such as micro-Doppler signatures and EMD readily provides a feature vector that can be utilized for classification. For classification, the method of a Support Vector Machine (SVMs) was chosen. SVMs have been widely used as a method of pattern recognition due to their ability to generalize well and also because of their moderately simple implementation. In this paper, we discuss the ability of these methods to accurately identify human movements based on their micro-Doppler signatures obtained from S-band and millimeter-wave radar systems. Comparisons will also be made based on experimental results from each of these radar systems. Furthermore, we will present simulations of micro-Doppler movements for stationary subjects that will enable us to compare our experimental Doppler data to what we would expect from an "ideal" movement.

  3. Techniques for clutter suppression in the presence of body movements during the detection of respiratory activity through UWB radars.

    PubMed

    Lazaro, Antonio; Girbau, David; Villarino, Ramon

    2014-02-07

    This paper focuses on the feasibility of tracking the chest wall movement of a human subject during respiration from the waveforms recorded using an impulse-radio (IR) ultra-wideband radar. The paper describes the signal processing to estimate sleep apnea detection and breathing rate. Some techniques to solve several problems in these types of measurements, such as the clutter suppression, body movement and body orientation detection are described. Clutter suppression is achieved using a moving averaging filter to dynamically estimate it. The artifacts caused by body movements are removed using a threshold method before analyzing the breathing signal. The motion is detected using the time delay that maximizes the received signal after a clutter removing algorithm is applied. The periods in which the standard deviations of the time delay exceed a threshold are considered macro-movements and they are neglected. The sleep apnea intervals are detected when the breathing signal is below a threshold. The breathing rate is determined from the robust spectrum estimation based on Lomb periodogram algorithm. On the other hand the breathing signal amplitude depends on the body orientation respect to the antennas, and this could be a problem. In this case, in order to maximize the signal-to-noise ratio, multiple sensors are proposed to ensure that the backscattered signal can be detected by at least one sensor, regardless of the direction the human subject is facing. The feasibility of the system is compared with signals recorded by a microphone.

  4. Ergonomics in designing process: dialogue between designers, executors and users in the maintenance activity of radars in an oil refinery.

    PubMed

    Menegon, Fabrício Augusto; Rodrigues, Daniela da Silva; Fontes, Andréa Regina Martins; Menegon, Nilton Luiz

    2012-01-01

    This paper aims to discuss the role of ergonomics in design process using the dialogue developed by designers, implementers and users in an oil refinery. It was possible to identify the need of minimizing the postural constraints, risk of accidents, mechanical shocks and to enlarge safety perception in the access and permanency of the users at the workspace. It has been determined and validated by workers and managers to implement different deadlines depending on programming, viability and execution time for the improvements proposed. In a long-term: it was proposed the substitution of the ladders with time planning according to the maintenance program of the tanks; in a short-time: it was suggested the expansion of the existing platforms, implementation of a walkway connection provided with guardrails between the upper access of the side ladder and the repositioning of radar set and aerial aiming at the usage by workers at the workstation of the new platform. It was also elaborated eight typologies of intervention, according to the request, type of tank, material stored, and its setting place. The design process arises from ergonomics workplace analysis that presents concepts for solutions which was a mediator tool to be settled between users and implementers.

  5. Measurement of higher-order mode losses in SPEAR II by shift in synchrotron phase and increase in net cavity power

    SciTech Connect

    Not Available

    1988-01-01

    It has been estimated that the loss to higher-order cavity modes in SPEAR II will be 135 keV per cavity at 100 mA for a 10-cm bunch (sigma/sub z/ = 5 cm). This corresponds to a loss of 10 MeV for a 50-m PEP structure. The power lost to higher modes in each SPEAR II cavity at 100 mA would be 13.5 kW. A loss of this order can be measured by calorimetry. This loss is also large enough to cause a significant increase in the net rf power input into the cavities over the power input with no higher-mode excitation. In addition, the higher-mode loss can also produce a measurable shift in the synchronous phase angle. Numbers for these effects are computed in this paper.

  6. Female Partner Acceptance as a Predictor of Men's Readiness to Undergo Voluntary Medical Male Circumcision in Zambia: The Spear and Shield Project.

    PubMed

    Cook, Ryan; Jones, Deborah; Redding, Colleen A; Zulu, Robert; Chitalu, Ndashi; Weiss, Stephen M

    2016-11-01

    The World Health Organization has recommended the scale-up of voluntary medical male circumcision (VMMC) for HIV prevention in sub-Saharan Africa; however, men are often uninterested in undergoing VMMC. The Spear & Shield project enrolled 668 men and female partners from ten Zambian community health centers into parallel interventions promoting VMMC for HIV prevention or time-matched control conditions. A mediation model was utilized to examine the relationships between changes in women's acceptance of VMMC and men's readiness to undergo the procedure. Results demonstrated that, at 12 months post-intervention, a 5.9 % increase in the likelihood of undergoing VMMC among men in the experimental condition could be attributed to increased women's acceptance. From a public health perspective, involving women in VMMC promotion interventions such as the Spear & Shield project could significantly impact the demand for VMMC in Zambia.

  7. Female Partner Acceptance as a Predictor of Men's Readiness to Undergo Voluntary Medical Male Circumcision in Zambia: The Spear and Shield Project

    PubMed Central

    Cook, Ryan; Jones, Deborah; Redding, Colleen A.; Zulu, Robert; Chitalu, Ndashi; Weiss, Stephen M.

    2015-01-01

    The World Health Organization has recommended the scale-up of voluntary medical male circumcision (VMMC) for HIV prevention in sub-Saharan Africa; however, men are often uninterested in undergoing VMMC. The Spear & Shield project enrolled 668 men and female partners from ten Zambian community health centers into parallel interventions promoting VMMC for HIV prevention or time-matched control conditions. A mediation model was utilized to examine the relationships between changes in women's acceptance of VMMC and men's readiness to undergo the procedure. Results demonstrated that, at 12 months post-intervention, a 5.9 % increase in the likelihood of undergoing VMMC among men in the experimental condition could be attributed to increased women's acceptance. From a public health perspective, involving women in VMMC promotion interventions such as the Spear & Shield project could significantly impact the demand for VMMC in Zambia. PMID:25931242

  8. 30. Perimeter acquisition radar building room #318, showing radar control. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Perimeter acquisition radar building room #318, showing radar control. Console and line printers - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  9. 3. VIEW NORTHWEST, height finder radar towers, and radar tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW NORTHWEST, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  10. SMAP Radar Processing and Calibration

    NASA Technical Reports Server (NTRS)

    West, R.; Jaruwatanadilok, S.; Kwoun, O.; Chaubell, M.

    2013-01-01

    The Soil Moisture Active Passive (SMAP) mission is part of the NASA space-based Earth observation program, and consists of an L-band radar and radiometer scheduled for launch into sun synchronous orbit in late 2014. A joint effort of the Jet Propulsion Laboratory (JPL) and the Goddard Space Flight Center (GSFC), the SMAP mission draws heavily on the design and risk reduction heritage of the Hydrosphere State (Hydros) mission [1], [2]. The SMAP science and applications objectives are to: 1) understand processes that link the terrestrial water, energy and carbon cycles, 2) estimate global water and energy fluxes at the land surface, 3) quantify net carbon flux in boreal landscapes, 4) enhance weather and climate forecast skill, and 5) develop improved flood prediction and drought monitoring capability. To meet these science objectives, SMAP ground processing will combine the attributes of the radar and radiometer observations (in terms of their spatial resolution and sensitivity to soil moisture, surface roughness, and vegetation) to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Model sensitivities translate the soil moisture accuracy to a radar backscatter accuracy of 1 dB (1 sigma) at 3 km resolution and a brightness temperature accuracy of 1.3 K at 40 km resolution. This paper will describe the level 1 radar processing and calibration challenges and the choices made so far for the algorithms and software implementation.

  11. Radar Image of Galapagos Island

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image showing part of Isla Isabella in the western Galapagos Islands. It was taken by the L-band radar in HH polarization from the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar on the 40th orbit of the space shuttle Endeavour. The image is centered at about 0.5 degree south latitude and 91 degrees west longitude and covers an area of 75 by 60 kilometers (47 by 37 miles). The radar incidence angle at the center of the image is about 20 degrees.

    The western Galapagos Islands, which lie about 1,200 kilometers (750 miles) west of Ecuador in the eastern Pacific, have six active volcanoes similar to the volcanoes found in Hawaii. Since the time of Charles Darwin's visit to the area in 1835, there have been over 60 recorded eruptions of these volcanoes. This SIR-C/X-SAR image of Alcedo and Sierra Negra volcanoes shows the rougher lava flows as bright features, while ash deposits and smooth pahoehoe lava flows appear dark. A small portion of Isla Fernandina is visible in the extreme upper left corner of the image.

    The Galapagos Islands are one of the SIR-C/X-SAR supersites and data of this area will be taken several times during the flight to allow scientists to conduct topographic change studies and to search for different lava flow types, ash deposits and fault lines.

    Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes

  12. Planetary radar studies

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.; Cutts, J. A.

    1981-01-01

    A catalog of lunar and radar anomalies was generated to provide a base for comparison with Venusian radar signatures. The relationships between lunar radar anomalies and regolith processes were investigated, and a consortium was formed to compare lunar and Venusian radar images of craters. Time was scheduled at the Arecibo Observatory to use the 430 MHz radar to obtain high resolution radar maps of six areas of the lunar suface. Data from 1978 observations of Mare Serenitas and Plato are being analyzed on a PDP 11/70 computer to construct the computer program library necessary for the eventual reduction of the May 1981 and subsequent data acquisitions. Papers accepted for publication are presented.

  13. Determination of Large-Scale Cloud Ice Water Concentration by Combining Surface Radar and Satellite Data in Support of ARM SCM Activities

    SciTech Connect

    Liu, Guosheng

    2013-03-15

    water contents in support of cloud modeling activities. The approach of the study is to expand a (surface) point measurement to an (satellite) area measurement. That is, the study takes the advantage of the high quality cloud measurements (particularly cloud radar and microwave radiometer measurements) at the point of the ARM sites. We use the cloud ice water characteristics derived from the point measurement to guide/constrain a satellite retrieval algorithm, then use the satellite algorithm to derive the 3-D cloud ice water distributions within an 10° (latitude) x 10° (longitude) area. During the research period, we have developed, validated and improved our cloud ice water retrievals, and have produced and archived at ARM website as a PI-product of the 3-D cloud ice water contents using combined satellite high-frequency microwave and surface radar observations for SGP March 2000 IOP and TWP-ICE 2006 IOP over 10 deg. x 10 deg. area centered at ARM SGP central facility and Darwin sites. We have also worked on validation of the 3-D ice water product by CloudSat data, synergy with visible/infrared cloud ice water retrievals for better results at low ice water conditions, and created a long-term (several years) of ice water climatology in 10 x 10 deg. area of ARM SGP and TWP sites and then compared it with GCMs.

  14. Historical sketch: Radar geology

    NASA Technical Reports Server (NTRS)

    Macdonald, H.

    1980-01-01

    A chronological assessment is given of the broad spectra of technology associated with radar geology. Particular attention is given to the most recent developments made in the areas of microwave Earth resources applications and geologic remote sensing from aircraft and satellite. The significance of space derived radar in geologic investigations is discussed and the scientific basis for exploiting the sensitivity of radar signals to various aspects of geologic terrain is given.

  15. Sports related concussion and spinal injuries: the need for changing spearing rules at the National Capital Amateur Football Association (NCAFA).

    PubMed Central

    Pelletier, Jacques C

    2006-01-01

    Introduction Returning an athlete to play following a spinal or concussive injury remains a challenge for the health practitioner making the decision. Among the possible mechanisms responsible for such injuries in amateur football, the concept of “spearing” has attracted a great deal of attention in sport medicine. Objective The purpose of this paper is to present a review of the diagnosis and treatment of the potentially catastrophic neck and head injuries caused by spearing in Canadian amateur football and to suggest the role the chiropractic profession can have in their prevention. It proposes to follow the recommendations advocated by the National Capital Amateur Football Association (NCAFA) athletic trainers group, led by a chiropractor. Methods Information regarding the concepts and prevention of “spearing”, concussion and spinal injuries at the amateur football level in both the United States and Canada was obtained using the following computerized search methods: PubMed – MeSH (via the National Center for Biotechnology Information (NCBI); The Index to Chiropractic Literature (ICL); Google Scholar Beta. Recent (2005) information on sports related spinal injuries and concussion were obtained by attendance at the 2005 Sports Related Concussion and Spine Injury Conference. Foxborough, Massachusetts. From a total of 698 references, 63 were retained. Conclusion Literature search yields very little information regarding Canadian statistics for amateur football neck and head injuries. The author encourages such injury data collecting and proposes that original Canadian studies and statistical analyses be carried out, such as those from diverse sports groups in the United States and abroad.1, 2, 3 The NCAFA group of trainers recommends a changing of the rules for “spearing” within the league and advocates gathering of Canadian based sports injury statistics. It also recognizes the need for public presentations (of concussion/spinal injuries).5 This

  16. Saturation and hysteresis effects in ionospheric modification experiments observed by the CUTLASS and EISCAT radars

    NASA Astrophysics Data System (ADS)

    Wright, D. M.; Davies, J. A.; Yeoman, T. K.; Robinson, T. R.; Shergill, H.

    2006-03-01

    The results of high latitude ionospheric modification experiments utilising the EISCAT heating facility at Tromsø are presented. As a result of the interaction between the high power pump waves and upper hybrid waves in the ionosphere, field-aligned electron density irregularities are artificially excited. Observations of these structures with the CUTLASS coherent HF radars and the EISCAT incoherent UHF radar exhibit hysteresis effects as the heater output power is varied. These are explained in terms of the two-stage mechanism which leads to the growth of the irregularities. Experiments which involve preconditioning of the ionosphere also indicate that hysteresis could be exploited to maximise the intensity of the field-aligned irregularities, especially where the available heater power is limited.

    In addition, the saturation of the irregularity amplitude is considered. Although, the rate of irregularity growth becomes less rapid at high heater powers it does not seem to fully saturate, indicating that the amplification would continue beyond the capabilities of the Tromsø heater - currently the most powerful of its kind. It is shown that the CUTLASS radars are sensitive to irregularities produced by very low heater powers (effective radiated powers <4 MW). This fact is discussed from the perspective of a new heating facility, SPEAR, located on Spitzbergen and capable of transmitting high frequency radio waves with an effective radiated power ~10% of that of the Tromsø heater (28MW).

  17. Monitoring by holographic radar systems

    NASA Astrophysics Data System (ADS)

    Catapano, Ilaria; Crocco, Lorenzo; Affinito, Antonio; Gennarelli, Gianluca; Soldovieri, Francesco

    2013-04-01

    Nowadays, radar technology represents a significant opportunity to collect useful information for the monitoring and conservation of critical infrastructures. Radar systems exploit the non-invasive interaction between the matter and the electromagnetic waves at microwave frequencies. Such an interaction allows obtaining images of the region under test from which one can infer the presence of potential anomalies such as deformations, cracks, water infiltrations, etc. This information turns out to be of primary importance in practical scenarios where the probed structure is in a poor state of preservation and renovation works must be planned. In this framework, the aim of this contribution is to describe the potentialities of the holographic radar Rascan 4/4000, a holographic radar developed by Remote Sensing Laboratory of Bauman Moscow State Technical University, as a non-destructive diagnostic tool capable to provide, in real-time, high resolution subsurface images of the sounded structure [1]. This radar provides holograms of hidden anomalies from the amplitude of the interference signal arising between the backscattered signal and a reference signal. The performance of the holographic radar is appraised by means of several experiments. Preliminary tests concerning the imaging below the floor and inside wood structures are carried out in controlled conditions at the Electromagnetic Diagnostic Laboratory of IREA-CNR. After, with reference to bridge monitoring for security aim, the results of a measurement campaign performed on the Musmeci bridge are presented [2]. Acknowledgments This research has been performed in the framework of the "Active and Passive Microwaves for Security and Subsurface imaging (AMISS)" EU 7th Framework Marie Curie Actions IRSES project (PIRSES-GA-2010-269157). REFERENCES [1] S. Ivashov, V. Razevig, I. Vasilyev, A. Zhuravlev, T. Bechtel, L. Capineri, The holographic principle in subsurface radar technology, International Symposium to

  18. Radar Tomography of Moving Targets

    DTIC Science & Technology

    2005-09-01

    resolution limitations of CW, SAR and ISAR radar and the theory on tomographic processing. The following sections briefly review the activities...this form of logic to the case of SAR imaging. Here the cross range resolution is given by: )2/sin(4 θ λδ Δ =cr (which is approximately equivalent to...the image. The multilook technique was used to compare the range-Doppler results to the final narrowband tomographic technique. The multilook

  19. Lunar Radar Cross Section at Low Frequency

    NASA Technical Reports Server (NTRS)

    Rodriguez, P.; Kennedy, E. J.; Kossey, P.; McCarrick, M.; Kaiser, M. L.; Bougeret, J.-L.; Tokarev, Y. V.

    2002-01-01

    Recent bistatic measurements of the lunar radar cross-section have extended the spectrum to long radio wavelength. We have utilized the HF Active Auroral Research Program (HAARP) radar facility near Gakona, Alaska to transmit high power pulses at 8.075 MHz to the Moon; the echo pulses were received onboard the NASA/WIND spacecraft by the WAVES HF receiver. This lunar radar experiment follows our previous use of earth-based HF radar with satellites to conduct space experiments. The spacecraft was approaching the Moon for a scheduled orbit perturbation when our experiment of 13 September 2001 was conducted. During the two-hour experiment, the radial distance of the satellite from the Moon varied from 28 to 24 Rm, where Rm is in lunar radii.

  20. Earth Surface Change as Viewed by the Spaceborne Imaging Radar-C. X-Band Synthetic Aperture Radar (SIR-C/X-SAR) and shuttle Hand-Held Photographs

    NASA Technical Reports Server (NTRS)

    Evans, D. L.; Stofan, E. R.; Jones, T. D.; Godwin, L.

    1994-01-01

    The Spaceborne Imaging Radar-C, X-Band Synthetic Aperture Radar (SIR-C/X-SAR) was launched on space shuttle Endeavour at 7:05 AM EDT, Saturday, April 9, 1994 as part of the Space Radar Lab (SRL-1). Soon after launch, the radars were activated and began arount the clock operations which lasted for the next 10 days.

  1. Radar illusion via metamaterials

    NASA Astrophysics Data System (ADS)

    Jiang, Wei Xiang; Cui, Tie Jun

    2011-02-01

    An optical illusion is an image of a real target perceived by the eye that is deceptive or misleading due to a physiological illusion or a specific visual trick. The recently developed metamaterials provide efficient approaches to generate a perfect optical illusion. However, all existing research on metamaterial illusions has been limited to theory and numerical simulations. Here, we propose the concept of a radar illusion, which can make the electromagnetic (EM) image of a target gathered by radar look like a different target, and we realize a radar illusion device experimentally to change the radar image of a metallic target into a dielectric target with predesigned size and material parameters. It is well known that the radar signatures of metallic and dielectric objects are significantly different. However, when a metallic target is enclosed by the proposed illusion device, its EM scattering characteristics will be identical to that of a predesigned dielectric object under the illumination of radar waves. Such an illusion device will confuse the radar, and hence the real EM properties of the metallic target cannot be perceived. We designed and fabricated the radar illusion device using artificial metamaterials in the microwave frequency, and good illusion performances are observed in the experimental results.

  2. Metamaterial for Radar Frequencies

    DTIC Science & Technology

    2012-09-01

    Circuit Board RAM Radar Absorbing Material RCS Radar Cross Section SNR Signal-to-Noise Ratio SNG Single-Negative SRR Split Ring Resonator...although some can be single-negative ( SNG ). DNG refers to material with simultaneous negative real parts of the permittivity r  and permeability

  3. Synchronization in multistatic radar

    NASA Astrophysics Data System (ADS)

    Jubrink, H. G.

    1993-08-01

    This report gives a summary of multistatic radar principles and synchronization methods. Different methods are described using direct and indirect synchronization. The report also presents a general review of synchronization methods for the future. Two LORAN C receivers have been analyzed for use as local reference oscillators in multistatic radar.

  4. The PROUST radar

    NASA Technical Reports Server (NTRS)

    Bertin, F.; Glass, M.; Ney, R.; Petitdidier, M.

    1986-01-01

    The Stratosphere-Troposphere (ST) radar called PROUST works at 935 MHz using the same klystron and antenna as the coherent-scatter radar. The use of this equipment for ST work has required some important modifications of the transmitting system and the development of receiving, data processing and acquisition (1984,1985) equipment. The modifications are discussed.

  5. Noncooperative rendezvous radar system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A fire control radar system was developed, assembled, and modified. The baseline system and modified angle tracking system are described along with the performance characteristics of the baseline and modified systems. Proposed changes to provide additional techniques for radar evaluation are presented along with flight test data.

  6. Polarization Radar Processing Technology

    DTIC Science & Technology

    1989-10-01

    Oi"C FILE ( J qII RADC-TR-89-144 In-House Report October 1989 AD-A215 242 POLARIZATION RADAR PROCESSING TECHNOLOGY Kenneth C. Stiefvater, Russell D...NO. NO. NO. ACCESSION NO. 62702F 4506 11 58 11. TITLE (Include Security Classification) POLARIZATION RADAR PROCESSING TECHNOLOGY 12. PERSONAL AUTHOR(S

  7. Determination of radar MTF

    SciTech Connect

    Chambers, D.

    1994-11-15

    The ultimate goal of the Current Meter Array (CMA) is to be able to compare the current patterns detected with the array with radar images of the water surface. The internal wave current patterns modulate the waves on the water surface giving a detectable modulation of the radar cross-section (RCS). The function relating the RCS modulations to the current patterns is the Modulation Transfer Function (MTF). By comparing radar images directly with co-located CMA measurements the MTF can be determined. In this talk radar images and CMA measurements from a recent experiment at Loch Linnhe, Scotland, will be used to make the first direct determination of MTF for an X and S band radar at low grazing angles. The technical problems associated with comparing radar images to CMA data will be explained and the solution method discussed. The results suggest the both current and strain rate contribute equally to the radar modulation for X band. For S band, the strain rate contributes more than the current. The magnitude of the MTF and the RCS modulations are consistent with previous estimates when the wind is blowing perpendicular to the radar look direction.

  8. Java Radar Analysis Tool

    NASA Technical Reports Server (NTRS)

    Zaczek, Mariusz P.

    2005-01-01

    Java Radar Analysis Tool (JRAT) is a computer program for analyzing two-dimensional (2D) scatter plots derived from radar returns showing pieces of the disintegrating Space Shuttle Columbia. JRAT can also be applied to similar plots representing radar returns showing aviation accidents, and to scatter plots in general. The 2D scatter plots include overhead map views and side altitude views. The superposition of points in these views makes searching difficult. JRAT enables three-dimensional (3D) viewing: by use of a mouse and keyboard, the user can rotate to any desired viewing angle. The 3D view can include overlaid trajectories and search footprints to enhance situational awareness in searching for pieces. JRAT also enables playback: time-tagged radar-return data can be displayed in time order and an animated 3D model can be moved through the scene to show the locations of the Columbia (or other vehicle) at the times of the corresponding radar events. The combination of overlays and playback enables the user to correlate a radar return with a position of the vehicle to determine whether the return is valid. JRAT can optionally filter single radar returns, enabling the user to selectively hide or highlight a desired radar return.

  9. Fusion of radar and satellite target measurements

    NASA Astrophysics Data System (ADS)

    Moy, Gabriel; Blaty, Donald; Farber, Morton; Nealy, Carlton

    2011-06-01

    A potentially high payoff for the ballistic missile defense system (BMDS) is the ability to fuse the information gathered by various sensor systems. In particular, it may be valuable in the future to fuse measurements made using ground based radars with passive measurements obtained from satellite-based EO/IR sensors. This task can be challenging in a multitarget environment in view of the widely differing resolution between active ground-based radar and an observation made by a sensor at long range from a satellite platform. Additionally, each sensor system could have a residual pointing bias which has not been calibrated out. The problem is further compounded by the possibility that an EO/IR sensor may not see exactly the same set of targets as a microwave radar. In order to better understand the problems involved in performing the fusion of metric information from EO/IR satellite measurements with active microwave radar measurements, we have undertaken a study of this data fusion issue and of the associated data processing techniques. To carry out this analysis, we have made use of high fidelity simulations to model the radar observations from a missile target and the observations of the same simulated target, as gathered by a constellation of satellites. In the paper, we discuss the improvements seen in our tests when fusing the state vectors, along with the improvements in sensor bias estimation. The limitations in performance due to the differing phenomenology between IR and microwave radar are discussed as well.

  10. Spaceborne weather radar

    NASA Technical Reports Server (NTRS)

    Meneghini, Robert; Kozu, Toshiaki

    1990-01-01

    The present work on the development status of spaceborne weather radar systems and services discusses radar instrument complementarities, the current forms of equations for the characterization of such aspects of weather radar performance as surface and mirror-image returns, polarimetry, and Doppler considerations, and such essential factors in spaceborne weather radar design as frequency selection, scanning modes, and the application of SAR to rain detection. Attention is then given to radar signal absorption by the various atmospheric gases, rain drop size distribution and wind velocity determinations, and the characteristics of clouds, as well as the range of available estimation methods for backscattering, single- and dual-wavelength attenuation, and polarimetric and climatological characteristics.

  11. Micropower impulse radar imaging

    SciTech Connect

    Hall, M.S.

    1995-11-01

    From designs developed at the Lawrence Livermore National Laboratory (LLNL) in radar and imaging technologies, there exists the potential for a variety of applications in both public and private sectors. Presently tests are being conducted for the detection of buried mines and the analysis of civil structures. These new systems use a patented ultra-wide band (impulse) radar technology known as Micropower Impulse Radar (GPR) imaging systems. LLNL has also developed signal processing software capable of producing 2-D and 3-D images of objects embedded in materials such as soil, wood and concrete. My assignment while at LLNL has focused on the testing of different radar configurations and applications, as well as assisting in the creation of computer algorithms which enable the radar to scan target areas of different geometeries.

  12. Intelligent radar data processing

    NASA Astrophysics Data System (ADS)

    Holzbaur, Ulrich D.

    The application of artificial intelligence principles to the processing of radar signals is considered theoretically. The main capabilities required are learning and adaptation in a changing environment, processing and modeling information (especially dynamics and uncertainty), and decision-making based on all available information (taking its reliability into account). For the application to combat-aircraft radar systems, the tasks include the combination of data from different types of sensors, reacting to electronic counter-countermeasures, evaluation of how much data should be acquired (energy and radiation management), control of the radar, tracking, and identification. Also discussed are related uses such as monitoring the avionics systems, supporting pilot decisions with respect to the radar system, and general applications in radar-system R&D.

  13. 4. VIEW NORTHEAST, radar tower (unknown function), prime search radar ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW NORTHEAST, radar tower (unknown function), prime search radar tower, emergency power building, and height finder radar tower - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  14. 5. VIEW EAST, height finder radar towers, radar tower (unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW EAST, height finder radar towers, radar tower (unknown function), prime search radar tower, operations building, and central heating plant - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  15. Archive of ground penetrating radar data collected during USGS field activity 13BIM01—Dauphin Island, Alabama, April 2013

    USGS Publications Warehouse

    Forde, Arnell S.; Smith, Christopher G.; Reynolds, Billy J.

    2016-03-18

    From April 13 to 20, 2013, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS-SPCMSC) conducted geophysical and sediment sampling surveys on Dauphin Island, Alabama, as part of Field Activity 13BIM01. The objectives of the study were to quantify inorganic and organic accretion rates in back-barrier and mainland marsh and estuarine environments. Various field and laboratory methods were used to achieve these objectives, including subsurface imaging using Ground Penetrating Radar (GPR), sediment sampling, lithologic and microfossil analyses, and geochronology techniques to produce barrier island stratigraphic cross sections to help interpret the recent (last 2000 years) geologic evolution of the island.This data series report is an archive of GPR and associated Global Positioning System (GPS) data collected in April 2013 from Dauphin Island and adjacent barrier-island environments. In addition to GPR data, marsh core and vibracore data were also collected collected but are not reported (or included) in the current report. Data products, including elevation-corrected subsurface profile images of the processed GPR data, unprocessed digital GPR trace data, post-processed GPS data, Geographic Information System (GIS) files and accompanying Federal Geographic Data Committee (FGDC) metadata, can be downloaded from the Data Downloads page.

  16. Radar remote sensing in biology

    USGS Publications Warehouse

    Moore, Richard K.; Simonett, David S.

    1967-01-01

    The present status of research on discrimination of natural and cultivated vegetation using radar imaging systems is sketched. The value of multiple polarization radar in improved discrimination of vegetation types over monoscopic radars is also documented. Possible future use of multi-frequency, multi-polarization radar systems for all weather agricultural survey is noted.

  17. Radar applications overview

    NASA Astrophysics Data System (ADS)

    Greenspan, Marshall

    1996-06-01

    During the fifty years since its initial development as a means of providing early warning of airborne attacks against allied countries during World War II, radar systems have developed to the point of being highly mobile and versatile systems capable of supporting a wide variety of remote sensing applications. Instead of being tied to stationary land-based sites, radar systems have found their way into highly mobile land vehicles as well as into aircraft, missiles, and ships of all sizes. Of all these applications, however, the most exciting revolution has occurred in the airborne platform arena where advanced technology radars can be found in all shapes and sizes...ranging from the large AWACS and Joint STARS long range surveillance and targeting systems to small millimeter wave multi-spectral sensors on smart weapons that can detect and identify their targets through the use of highly sophisticated digital signal processing hardware and software. This paper presents an overview of these radar applications with the emphasis on modern airborne sensors that span the RF spectrum. It will identify and describe the factors that influence the parameters of low frequency and ultra wide band radars designed to penetrate ground and dense foliage environments and locate within them buried mines, enemy armor, and other concealed or camouflaged weapons of war. It will similarly examine the factors that lead to the development of airborne radar systems that support long range extended endurance airborne surveillance platforms designed to detect and precision-located both small high speed airborne threats as well as highly mobile time critical moving and stationary surface vehicles. The mission needs and associated radar design impacts will be contrasted with those of radar systems designed for high maneuverability rapid acquisition tactical strike warfare platforms, and shorter range cued air-to-surface weapons with integral smart radar sensors.

  18. Radar frequency radiation

    NASA Astrophysics Data System (ADS)

    Malowicki, E.

    1981-11-01

    A method is presented for the determination of radar frequency radiation power densities that the PAVE PAWS radar system could produce in its air and ground environment. The effort was prompted by the concern of the people in the vicinity of OTIS AFB MA and BEALE AFB CA about the possible radar frequency radiation hazard of the PAVE PAWS radar. The method is based on the following main assumptions that: (a) the total field can be computed as the vector summation of the individual fields due to each antenna element; (b) the individual field can be calculated using distances for which the field point is in the far field of the antenna element. An RFR computer program was coded for the RADC HE 6180 digital computer and exercised to calculate the radiation levels in the air and ground space for the present baseline and the possible Six DB and 10 DB growth systems of the PAVE PAWS radar system at OTIS AFB MA. The average radiation levels due to the surveillance fence were computed for three regions: in the air space in front of the radar, at the radar hazard fence at OTIS AFB MA and at representative ground points in the OTIS AFB vicinity. It was concluded that the radar frequency radiation of PAVE PAWS does not present a hazard to personnel provided there is no entry to the air hazard zone or to the area within the hazard fence. The method developed offers a cost effective way to determine radiation levels from a phased array radar especially in the near field and transition regions.

  19. space Radar Image of Long Valley, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    An area near Long Valley, California, was mapped by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavor on April 13, 1994, during the first flight of the radar instrument, and on October 4, 1994, during the second flight of the radar instrument. The orbital configurations of the two data sets were ideal for interferometric combination -- that is overlaying the data from one image onto a second image of the same area to create an elevation map and obtain estimates of topography. Once the topography is known, any radar-induced distortions can be removed and the radar data can be geometrically projected directly onto a standard map grid for use in a geographical information system. The 50 kilometer by 50 kilometer (31 miles by 31 miles) map shown here is entirely derived from SIR-C L-band radar (horizontally transmitted and received) results. The color shown in this image is produced from the interferometrically determined elevations, while the brightness is determined by the radar backscatter. The map is in Universal Transverse Mercator (UTM) coordinates. Elevation contour lines are shown every 50 meters (164 feet). Crowley Lake is the dark feature near the south edge of the map. The Adobe Valley in the north and the Long Valley in the south are separated by the Glass Mountain Ridge, which runs through the center of the image. The height accuracy of the interferometrically derived digital elevation model is estimated to be 20 meters (66 feet) in this image. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global

  20. A microprogrammable radar controller

    NASA Technical Reports Server (NTRS)

    Law, D. C.

    1986-01-01

    The Wave Propagation Lab. has completed the design and construction of a microprogrammable radar controller for atmospheric wind profiling. Unlike some radar controllers using state machines or hardwired logic for radar timing, this design is a high speed programmable sequencer with signal processing resources. A block diagram of the device is shown. The device is a single 8 1/2 inch by 10 1/2 inch printed circuit board and consists of three main subsections: (1) the host computer interface; (2) the microprogram sequencer; and (3) the signal processing circuitry. Each of these subsections are described in detail.

  1. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1981-01-01

    Efforts were focused on: (1) acquisition of radar data at Arecibo; (2) examination of raw data; (3) reduction of the unmodulated data to background-free, calibrated spectra; (4) integration and coherent analyses of the phase-coded data; and (5) calculation of Doppler shifts and preliminary values for echo limb-to-limb bandwidths, radar cross sections, and circular polarization ratios. Asteroids observed to data have radar properties distinct from those of the rocky terrestrial planets and those of the icy Galilean satellites.

  2. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1981-01-01

    Software to support all stages of asteroid radar observation and data analysis is developed. First-order analysis of all data in hand is complete. Estimates of radar cross sections, circular polarization ratios, and limb-to-limb echo spectral bandwidths for asteroids 7 Iris, 16 Psyche, 97 Klotho, 1862 Apollo, and 1915 Quetzalcoatl are reported. Radar observations of two previously unobserved asteroids were conducted. An Aten asteroid, 2100 Ra-Shalom, with the smallest known semimajor axis (0.83) was detected. Preliminary data reduction indicates a circular polarization ratio comparable to those of Apollo, Quetzalcoatl, and Toro.

  3. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1984-01-01

    The initial radar observations of the mainbelt asteroids 9 Metis, 27 Euterpe, and 60 Echo are examined. For each target, data are taken simultaneously in the same sense of circular polarization as transmitted as well as in the opposite (OC) sense. Estimates of the radar cross sections provide estimates of the circular polarization ratio, and the normalized OC radar cross section. The circular polarization ratio, is comparable to values measured for other large S type asteroids and for a few much smaller, Earth approaching objects, most of the echo is due to single reflection backscattering from smooth surface elements.

  4. Radar investigation of asteroids

    NASA Astrophysics Data System (ADS)

    Ostro, S. J.

    1981-11-01

    Software to support all stages of asteroid radar observation and data analysis is developed. First-order analysis of all data in hand is complete. Estimates of radar cross sections, circular polarization ratios, and limb-to-limb echo spectral bandwidths for asteroids 7 Iris, 16 Psyche, 97 Klotho, 1862 Apollo, and 1915 Quetzalcoatl are reported. Radar observations of two previously unobserved asteroids were conducted. An Aten asteroid, 2100 Ra-Shalom, with the smallest known semimajor axis (0.83) was detected. Preliminary data reduction indicates a circular polarization ratio comparable to those of Apollo, Quetzalcoatl, and Toro.

  5. Radar Remote Sensing

    NASA Technical Reports Server (NTRS)

    Rosen, Paul A.

    2012-01-01

    This lecture was just a taste of radar remote sensing techniques and applications. Other important areas include Stereo radar grammetry. PolInSAR for volumetric structure mapping. Agricultural monitoring, soil moisture, ice-mapping, etc. The broad range of sensor types, frequencies of observation and availability of sensors have enabled radar sensors to make significant contributions in a wide area of earth and planetary remote sensing sciences. The range of applications, both qualitative and quantitative, continue to expand with each new generation of sensors.

  6. To See the Unseen: A History of Planetary Radar Astronomy

    NASA Technical Reports Server (NTRS)

    Butrica, Andrew J.

    1996-01-01

    This book relates the history of planetary radar astronomy from its origins in radar to the present day and secondarily to bring to light that history as a case of 'Big Equipment but not Big Science'. Chapter One sketches the emergence of radar astronomy as an ongoing scientific activity at Jodrell Bank, where radar research revealed that meteors were part of the solar system. The chief Big Science driving early radar astronomy experiments was ionospheric research. Chapter Two links the Cold War and the Space Race to the first radar experiments attempted on planetary targets, while recounting the initial achievements of planetary radar, namely, the refinement of the astronomical unit and the rotational rate and direction of Venus. Chapter Three discusses early attempts to organize radar astronomy and the efforts at MIT's Lincoln Laboratory, in conjunction with Harvard radio astronomers, to acquire antenna time unfettered by military priorities. Here, the chief Big Science influencing the development of planetary radar astronomy was radio astronomy. Chapter Four spotlights the evolution of planetary radar astronomy at the Jet Propulsion Laboratory, a NASA facility, at Cornell University's Arecibo Observatory, and at Jodrell Bank. A congeries of funding from the military, the National Science Foundation, and finally NASA marked that evolution, which culminated in planetary radar astronomy finding a single Big Science patron, NASA. Chapter Five analyzes planetary radar astronomy as a science using the theoretical framework provided by philosopher of science Thomas Kuhn. Chapter Six explores the shift in planetary radar astronomy beginning in the 1970s that resulted from its financial and institutional relationship with NASA Big Science. Chapter Seven addresses the Magellan mission and its relation to the evolution of planetary radar astronomy from a ground-based to a space-based activity. Chapters Eight and Nine discuss the research carried out at ground

  7. Random FM-CW radar and its ECCM

    NASA Astrophysics Data System (ADS)

    Liu, Guosui; Shi, Xiangquan; Lu, Jinhui

    The principle of a random FM-CW radar system is introduced, and the range cutoff charactertistic (RCC) for the system is derived. In a fuze radar system, this radar can be used against passive jamming away from the point of range cutoff as well as against active jamming. Experimental results are presented which show that the random FM-CW radar system has RCC and ECCM properties. The system can be used as a short-range detection system, a low-altitude altimeter, and a blind landing device.

  8. Studies on Radar Sensor Networks

    DTIC Science & Technology

    2007-08-08

    through-foliage target detection using UWB radar sensor network based on real-world data; 2. Foliage clutter modeling using UWB radars; 3. Outdoor UWB...channel modeling based on field data; 4. Multi-target detection using radar sensor networks (theoretical studies); 5. SVD-QR and graph theory for MIMO...Superimposed code based channel assignment in multi-radio multi-channel wireless mesh networks. 15. SUBJECT TERMS Radar Sensor Network, UWB Radar, Sense

  9. Physical conditions in the low corona and chromosphere of solar active regions according to spectral radar measurements

    NASA Astrophysics Data System (ADS)

    Kaltman, T. I.; Bogod, V. M.; Stupishin, A. G.; Yasnov, L. V.

    2013-12-01

    The physical conditions in the low corona and chromosphere of solar active regions are studied. A diagnostics technique based on multiwave observations in the centimeter range, photospheric magnetic field extrapolation, and radioemission calculations has been applied. The calculated spatial and spectral structure of the radioemission has been compared with RATAN-600 spectral-polarization observations with a high spatial resolution. The effect of the plasma physical parameters on the emission structure character in a complex magnetic field topology in active regions is analyzed. Modeling of the spectral singularities at a quasi-periodic propagation of the radioemission is presented.

  10. Stanford Synchrotron Radiation Laboratory 1991 activity report. Facility developments January 1991--March 1992

    SciTech Connect

    Cantwell, K.; St. Pierre, M.

    1992-12-31

    SSRL is a national facility supported primarily by the Department of Energy for the utilization of synchrotron radiation for basic and applied research in the natural sciences and engineering. It is a user-oriented facility which welcomes proposals for experiments from all researchers. The synchrotron radiation is produced by the 3.5 GeV storage ring, SPEAR, located at the Stanford Linear Accelerator Center (SLAC). SPEAR is a fully dedicated synchrotron radiation facility which operates for user experiments 7 to 9 months per year. SSRL currently has 24 experimental stations on the SPEAR storage ring. There are 145 active proposals for experimental work from 81 institutions involving approximately 500 scientists. There is normally no charge for use of beam time by experimenters. This report summarizes the activity at SSRL for the period January 1, 1991 to December 31, 1991 for research. Facility development through March 1992 is included.

  11. Development of a rapid HPLC-UV method for simultaneous quantification of protodioscin and rutin in white and green asparagus spears.

    PubMed

    Lee, Eun Jin; Yoo, Kil Sun; Patil, Bhimanagouda S

    2010-01-01

    Asparagus (Asparagus officinalis L.) spears are rich in bioactive compounds such as protodioscin, a saponin, and rutin, a flavonoid. Protodioscin and rutin are routinely quantified separately, and an approach permitting simultaneous measurement would significantly improve speed of analysis. We have optimized an extraction procedure and modified a method of high-performance liquid chromatography by coupling to an ultraviolet detector to simultaneously analyze protodioscin and rutin in asparagus extracts. An acidic ethanol solvent was more efficient than methanol, acetonitrile, or water in coextraction of protodioscin and rutin. Protodioscin and rutin were detected at 210 nm, with retention times of 12.6 min and 7.9 min, respectively. The method was validated by high linear correlations between 3.13 and 1000.0 μg/mL for protodioscin (r(2)= 0.9999), and between 0.3 and 1087.5 μg/mL for rutin (r(2)= 0.9997). The limit(s) of detection and quantification for protodioscin were 1.6 μg/mL and 3.13 μg/mL, respectively, and for rutin 0.2 μg/mL and 0.3 μg/mL, respectively. White asparagus spears and the crown of the plants were revealed to be rich sources of protodioscin and contained 2.59 to 10.4 mg/g dry weight. Green asparagus spears, particularly the upper portion, were rich in rutin and contained between 1.51 and 7.29 mg/g dry weight.

  12. Laser Radar Animation

    NASA Video Gallery

    Laser and radar instruments aboard NASA aircraft provide measurements of the snow and ice surface and down to the bedrock under the ice. Lasers, with a shorter wavelength, measure the surface eleva...

  13. Multispectral imaging radar

    NASA Technical Reports Server (NTRS)

    Porcello, L. J.; Rendleman, R. A.

    1972-01-01

    A side-looking radar, installed in a C-46 aircraft, was modified to provide it with an initial multispectral imaging capability. The radar is capable of radiating at either of two wavelengths, these being approximately 3 cm and 30 cm, with either horizontal or vertical polarization on each wavelength. Both the horizontally- and vertically-polarized components of the reflected signal can be observed for each wavelength/polarization transmitter configuration. At present, two-wavelength observation of a terrain region can be accomplished within the same day, but not with truly simultaneous observation on both wavelengths. A multiplex circuit to permit this simultaneous observation has been designed. A brief description of the modified radar system and its operating parameters is presented. Emphasis is then placed on initial flight test data and preliminary interpretation. Some considerations pertinent to the calibration of such radars are presented in passing.

  14. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1983-01-01

    For 80 Sappho, 356 Liguria, 694 Ekard, and 2340 Hathor, data were taken simultaneously in the same sense of circular polarization as transmitted (SC) as well as in the opposite (OC) sense. Graphs show the average OC and SC radar echo power spectra soothed to a resolution of EFB Hz and plotted against Doppler frequency. Radar observations of the peculiar object 2201 Oljato reveal an unusual set of echo power spectra. The albedo and polarization ratio remain fairly constant but the bandwidths range from approximately 0.8 Hz to 1.4 Hz and the spectral shapes vary dramatically. Echo characteristics within any one date's approximately 2.5-hr observation period do not fluctuate very much. Laboratory measurements of the radar frequency electrical properties of particulate metal-plus-silicate mixtures can be combined with radar albedo estimates to constrain the bulk density and metal weight, fraction in a hypothetical asteroid regolith having the same particle size distribution as lab samples.

  15. Radar Cross Section Measurements

    DTIC Science & Technology

    1986-09-30

    Radar 54 17. Measured Range Sidelobe Performance of Chirp Radar 56 18. Range and Cross Range Image of Target Dror.’ŕ Vehicle 57 19. Incoherent rms...the measured range resolution, 4.9 in, closely agrees with the theoretical performance for this weighting. The measured range sidelobe performance...Interval 4.89in. 2% kHz 300 kHz 310 kHz (b) Expanded Scale + 5 ft from Target Figure 17. Measured Range Sidelobe Performance of

  16. Airborne MIMO GMTI Radar

    DTIC Science & Technology

    2011-03-31

    applications [1], [2], [3], [4]. [5]. [6]. [7]. [8]. [9]. [10]. [11]. [12]. Conventional phased array radars form a single coherent transmit beam and...intentionally left blank. 1. INTRODUCTION Conventional phased - array radars form a single coherent transmit beam and measure the backscattered response... steering vector for a SI MO array with nr"/? receiver phase centers located at positions xm + y„. This is how the MIMO virtual array arises. The waveforms

  17. The Comet Radar Explorer Mission

    NASA Astrophysics Data System (ADS)

    Asphaug, Erik; Belton, Mike; Bockelee-Morvan, Dominique; Chesley, Steve; Delbo, Marco; Farnham, Tony; Gim, Yonggyu; Grimm, Robert; Herique, Alain; Kofman, Wlodek; Oberst, Juergen; Orosei, Roberto; Piqueux, Sylvain; Plaut, Jeff; Robinson, Mark; Sava, Paul; Heggy, Essam; Kurth, William; Scheeres, Dan; Denevi, Brett; Turtle, Elizabeth; Weissman, Paul

    2014-11-01

    Missions to cometary nuclei have revealed major geological surprises: (1) Global scale layers - do these persist through to the interior? Are they a record of primary accretion? (2) Smooth regions - are they landslides originating on the surface? Are they cryovolcanic? (3) Pits - are they impact craters or sublimation pits, or rooted in the interior? Unambiguous answers to these and other questions can be obtained by high definition 3D radar reflection imaging (RRI) of internal structure. RRI can answer many of the great unknowns in planetary science: How do primitive bodies accrete? Are cometary nuclei mostly ice? What drives their spectacular activity and evolution? The Comet Radar Explorer (CORE) mission will image the detailed internal structure of the nucleus of 10P/Tempel 2. This ~16 x 8 x 7 km Jupiter Family Comet (JFC), or its parent body, originated in the outer planets region possibly millions of years before planet formation. CORE arrives post-perihelion and observes the comet’s waning activity from safe distance. Once the nucleus is largely dormant, the spacecraft enters a ~20-km dedicated Radar Mapping Orbit (RMO). The exacting design of the RRI experiment and the precise navigation of RMO will achieve a highly focused 3D radar reflection image of internal structure, to tens of meters resolution, and tomographic images of velocity and attenuation to hundreds of meters resolution, tied to the gravity model and shape. Visible imagers will produce maps of the surface morphology, albedo, color, texture, and photometric response, and images for navigation and shape determination. The cameras will also monitor the structure and dynamics of the coma, and its dusty jets, allowing their correlation in 3D with deep interior structures and surface features. Repeated global high-resolution thermal images will probe the near-surface layers heated by the Sun. Derived maps of thermal inertia will be correlated with the radar boundary response, and photometry and

  18. Active radar guides missile to its target: receptor-based targeted treatment of hepatocellular carcinoma by nanoparticulate systems.

    PubMed

    Yan, Jing-Jun; Liao, Jia-Zhi; Lin, Ju-Sheng; He, Xing-Xing

    2015-01-01

    Patients with hepatocellular carcinoma (HCC) usually present at advanced stages and do not benefit from surgical resection, so drug therapy should deserve a prominent place in unresectable HCC treatment. But chemotherapy agents, such as doxorubicin, cisplatin, and paclitaxel, frequently encounter important problems such as low specificity and non-selective biodistribution. Recently, the development of nanotechnology led to significant breakthroughs to overcome these problems. Decorating the surfaces of nanoparticulate-based drug carriers with homing devices has demonstrated its potential in concentrating chemotherapy agents specifically to HCC cells. In this paper, we reviewed the current status of active targeting strategies for nanoparticulate systems based on various receptors such as asialoglycoprotein receptor, transferrin receptor, epidermal growth factor receptor, folate receptor, integrin, and CD44, which are abundantly expressed on the surfaces of hepatocytes or liver cancer cells. Furthermore, we pointed out their merits and defects and provided theoretical references for further research.

  19. Doppler radar sensing of fish physiological motion

    NASA Astrophysics Data System (ADS)

    Hafner, Noah

    The monitoring vital of signs for fish is critical for advancing the study of trophic and energetic strategies, distributions and behavior, environmental impact, and aquaculture approaches. Presented here is a new approach for monitoring fish metabolic state without the trauma and stress associated with capture, surgical ECG, or other implanted sensing systems. Original research contributions include analysis for radar operation under water, development of radar systems for aquatic operation, and application of these systems to non invasively sense the heart and gill motion of fish. Tilapia and Sturgeon were studied to test the efficacy across varied fish body shapes and sizes, ranging from 0.1 to 1.3m in snout to tail length. Monitoring experiments were conducted with eleven tilapia and three sturgeons to assess activity level participated in these experiments, the results from which include activity level monitoring (tilapia: still or fidgeting 94% of time observed), ventilation rate (tilapia: 42 bpm, sturgeon: 145 bpm), and heart rate (tilapia: 41 bpm, sturgeon: 35 bpm). Bland-Altman analysis of radar and ECG measured heart rate indicate agreement between the two measurement techniques and the suitability of radar as an alternative to ECG. The initial steps for developing a system for practical application is also presented including designs for radar system miniaturization and discussion on further characterization steps with less constrained environments.

  20. TOPEX Project Radar Altimeter Development Requirements and Specifications, Version 6.0

    NASA Technical Reports Server (NTRS)

    Rossi, Laurence C.

    2003-01-01

    This document provides the guidelines by which the TOPEX Radar Altimeter hardware development effort for the TOPEX flight project shall be implemented and conducted. The conduct of this activity shall take maximum advantage of the efforts expended during the TOPEX Radar Altimeter Advanced Technology Model development program and other related Radar Altimeter development efforts. This document complies with the TOPEX Project Office document 633-420 (D-2218), entitled, "TOPEX Project Requirements and Constraints for the NASA Radar Altimeter" dated December 1987.

  1. Phased-array radar for airborne systems

    NASA Astrophysics Data System (ADS)

    Tahim, Raghbir S.; Foshee, James J.; Chang, Kai

    2003-09-01

    Phased array antenna systems, which support high pulse rates and high transmit power, are well suited for radar and large-scale surveillance. Sensors and communication systems can function as the eyes and ears for ballistic missile defense applications, providing early warning of attack, target detection and identification, target tracking, and countermeasure decision. In such applications, active array radar systems that contain solid-state transmitter sources and low-noise preamplifiers for transmission and reception are preferred over the conventional radar antennas, because the phased array radar offers the advantages of power management and efficiency, reliability, signal reception, beam steering target detection. The current phased array radar designs are very large, complex and expensive and less efficient because of high RF losses in the phase control circuits used for beam scan. Several thousands of phase shifters and drivers may be required for a single system thus making the system very complex and expensive. This paper describes the phased array radar system based on high power T/R modules, wide-band radiating planar antenna elements and very low loss wide-band phase control circuits (requiring reduced power levels) for beam scan. The phase shifter design is based on micro-strip feed lines perturbed by the proximity of voltage controlled piezoelectric transducer (PET). Measured results have shown an added insertion loss of less than 1 dB for a phase shift of 450 degrees from 2 to 20 GHz. The new wideband phased array radar design provides significant reduction in size cost and weight. Compared to the conventional phased array systems, the cost saving is more than 15 to 1.

  2. 66. VIEW SHOWING HOLD FOR RADAR CABLES AT RADAR SITE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    66. VIEW SHOWING HOLD FOR RADAR CABLES AT RADAR SITE, LOOKING NORTH Everett Weinreb, photographer, March 1988 - Mount Gleason Nike Missile Site, Angeles National Forest, South of Soledad Canyon, Sylmar, Los Angeles County, CA

  3. Calculations of neutron and photon source terms and attenuation profiles for the generic design of the SPEAR3 storage ring shield.

    PubMed

    Rokni, S H; Khater, H; Liu, J C; Mao, S; Vincke, H

    2005-01-01

    The FLUKA Monte Carlo particle generation and transport code was used to calculate shielding requirements for the 3 GeV, 500 mA SPEAR3 storage ring at the Stanford Synchrotron Radiation Laboratory. The photon and neutron dose equivalent source term data were simulated for a 3 GeV electron beam interacting with two typical target/shielding geometries in the ring. The targets simulated are a rectangular block of 0.7 cm thick copper and a 5 cm thick iron block, both tilted at 1 degree relative to the beam direction. Attenuation profiles for neutrons and photons in concrete and lead as a function of angle at different shield thicknesses were calculated. The first, second and equilibrium attenuation lengths of photons and neutrons in the shield materials are derived from the attenuation profiles. The source term data and the attenuation lengths were then used to evaluate the shielding requirements for the ratchet walls of all front-ends of the SPEAR3 storage ring.

  4. Radar Imaging of Mercury

    NASA Astrophysics Data System (ADS)

    Harmon, John K.

    2007-10-01

    Earth-based radar has been one of the few, and one of the most important, sources of new information about Mercury during the three decades since the Mariner 10 encounters. The emphasis during the past 15 years has been on full-disk, dual-polarization imaging of the planet, an effort that has been facilitated by the development of novel radar techniques and by improvements in radar systems. Probably the most important result of the imaging work has been the discovery and mapping of radar-bright features at the poles. The radar scattering properties of these features, and their confinement to permanently shaded crater floors, is consistent with volume backscatter from a low-loss volatile such as clean water ice. Questions remain, however, regarding the source and long-term stability of the putative ice, which underscores the need for independent confirmation by other observational methods. Radar images of the non-polar regions have also revealed a plethora of bright features, most of which are associated with fresh craters and their ejecta. Several very large impact features, with rays and other bright ejecta spreading over distances of 1,000 km or more, have been traced to source craters with diameters of 80-125 km. Among these large rayed features are some whose relative faintness suggests that they are being observed in an intermediate stage of degradation. Less extended ray/ejecta features have been found for some of the freshest medium-size craters such as Kuiper and Degas. Much more common are smaller (<40 km diameter) fresh craters showing bright rim-rings but little or no ray structure. These smaller radar-bright craters are particularly common over the H-7 quadrangle. Diffuse areas of enhanced depolarized brightness have been found in the smooth plains, including the circum-Caloris planitiae and Tolstoj Basin. This is an interesting finding, as it is the reverse of the albedo contrast seen between the radar-dark maria and the radar-bright cratered highlands

  5. Radar Imaging of Mercury

    NASA Astrophysics Data System (ADS)

    Harmon, John K.

    Earth-based radar has been one of the few, and one of the most important, sources of new information about Mercury during the three decades since the Mariner 10 encounters. The emphasis during the past 15 years has been on full-disk, dual-polarization imaging of the planet, an effort that has been facilitated by the development of novel radar techniques and by improvements in radar systems. Probably the most important result of the imaging work has been the discovery and mapping of radar-bright features at the poles. The radar scattering properties of these features, and their confinement to permanently shaded crater floors, is consistent with volume backscatter from a low-loss volatile such as clean water ice. Questions remain, however, regarding the source and long-term stability of the putative ice, which underscores the need for independent confirmation by other observational methods. Radar images of the non-polar regions have also revealed a plethora of bright features, most of which are associated with fresh craters and their ejecta. Several very large impact features, with rays and other bright ejecta spreading over distances of 1,000 km or more, have been traced to source craters with diameters of 80-125 km. Among these large rayed features are some whose relative faintness suggests that they are being observed in an intermediate stage of degradation. Less extended ray/ejecta features have been found for some of the freshest medium-size craters such as Kuiper and Degas. Much more common are smaller (<40 km diameter) fresh craters showing bright rim-rings but little or no ray structure. These smaller radar-bright craters are particularly common over the H-7 quadrangle. Diffuse areas of enhanced depolarized brightness have been found in the smooth plains, including the circum-Caloris planitiae and Tolstoj Basin. This is an interesting finding, as it is the reverse of the albedo contrast seen between the radar-dark maria and the radar-bright cratered highlands

  6. A barrier radar concept

    NASA Astrophysics Data System (ADS)

    Marshall, J.; Ball, C.; Weissman, I.

    A description is given of a low power, light-weight radar that can be quickly set up and operated on batteries for extended periods of time to detect airborne intruders. With low equipment and operating costs, it becomes practical to employ a multiplicity of such radars to provide an unbroken intrusion fence over the desired perimeter. Each radar establishes a single transmitted fan beam extending vertically from horizon to horizon. The beam is generated by a two-face array antenna built in an A-frame configuration and is shaped, through phasing of the array elements, to concentrate the transmitter power in a manner consistent with the expected operating altitude ceiling of the targets of interest. The angular width of this beam in the dimension transverse to the fan depends on the radar transmission frequency and the antenna aperture dimension, but is typically wide enough so that a target at the maximum altitude or range will require tens of seconds to pass through the beam. A large number of independent samples of radar data will thus be available to provide many opportunities for target detection.

  7. 33. Perimeter acquisition radar building room #320, perimeter acquisition radar ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. Perimeter acquisition radar building room #320, perimeter acquisition radar operations center (PAROC), contains the tactical command and control group equipment required to control the par site. Showing spacetrack monitor console - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  8. Coordinated Radar Resource Management for Networked Phased Array Radars

    DTIC Science & Technology

    2014-12-01

    Research and Development Canada Ottawa, Canada K1A 0Z4 Email: Peter.Moo@drdc-rddc.gc.ca Abstract A phased array radar has the ability to rapidly and...search and Development Canada (DRDC) Ottawa to analyse the performance of radar resource management techniques for naval radars operating in a littoral

  9. Phase modulating the Urbana radar

    NASA Technical Reports Server (NTRS)

    Herrington, L. J., Jr.; Bowhill, S. A.

    1983-01-01

    The design and operation of a switched phase modulation system for the Urbana Radar System are discussed. The system is implemented and demonstrated using a simple procedure. The radar system and circuits are described and analyzed.

  10. Tropical Rainfall Measuring Mission (TRMM) project. VI - Spacecraft, scientific instruments, and launching rocket. Part 4 - TRMM rain radar

    NASA Technical Reports Server (NTRS)

    Meneghini, Robert; Atlas, David; Awaka, Jun; Okamoto, Ken'ichi; Ihara, Toshio; Nakamura, Kenji; Kozu, Toshiaki; Manabe, Takeshi

    1990-01-01

    The basic system parameters for the Tropical Rainfall Measuring Mission (TRMM) radar system are frequency, beamwidth, scan angle, resolution, number of independent samples, pulse repetition frequency, data rate, and so on. These parameters were chosen to satisfy NASA's mission requirements. Six candidates for the TRMM rain radar were studied. The study considered three major competitive items: (1) a pulse-compression radar vs. a conventional radar; (2) an active-array radar with a solid state power amplifier vs. a passive-array radar with a traveling-wave-tube amplifier; and (3) antenna types (planar-array antenna vs. cylindrical parabolic antenna). Basic system parameters such as radar sensitivities, power consumption, weight, and size of these six types are described. Trade-off studies of these cases show that the non-pulse-compression active-array radar with a planar array is considered to be the most suitable candidate for the TRMM rain radar at 13.8 GHz.

  11. Broad perspectives in radar for ocean measurements

    NASA Technical Reports Server (NTRS)

    Jain, A.

    1978-01-01

    The various active radar implementation options available for the measurement functions of interest for the SEASAT follow-on missions were evaluated. These functions include surface feature imaging, surface pressure and vertical profile, atmospheric sounding, surface backscatter and wind speed determination, surface current location, wavelength spectra, sea surface topography, and ice/snow thickness. Some concepts for the Synthetic Aperture Imaging Radar were examined that may be useful in the design and selection of the implementation options for these missions. The applicability of these instruments for the VOIR mission was also kept under consideration.

  12. Coherent IR radar technology

    NASA Astrophysics Data System (ADS)

    Gschwendtner, A. B.; Harney, R. C.; Hull, R. J.

    Recent progress in the development of coherent IR radar equipment is reviewed, focusing on the Firepond laser radar installation and the more compact systems derived for it. The design and capabilities of Firepond as a long-range satellite-tracking device are outlined. The technological improvements necessary to make laser radar mobile are discussed: a lightweight, stable 5-10-W transmitter laser for both CW and pulsed operation, a 12-element HgCdTe detector array, an eccentric-pupil Ritchey-Chretien telescope, and a combination of near-field phase modification and anamorphic expansion to produce a fan beam of relatively uniform intensity. Sample images obtained with a prototype system are shown, and the applicability of the mobile system to range-resolved coherent DIAL measurement is found to be similar to that of a baseline DIAL system.

  13. The MST Radar Technique

    NASA Technical Reports Server (NTRS)

    Balsley, B. B.

    1985-01-01

    The past ten year have witnessed the development of a new radar technique to examine the structure and dynamics of the atmosphere between roughly 1 to 100 km on a continuous basis. The technique is known as the MST (for Mesosphere-Stratosphere-Troposphere) technique and is usable in all weather conditions, being unaffected by precipitation or cloud cover. MST radars make use of scattering from small scale structure in the atmospheric refractive index, with scales of the order of one-half the radar wavelength. Pertinent scale sizes for middle atmospheric studies typically range between a fraction of a meter and a few meters. The structure itself arises primarily from atmospheric turbulence. The technique is briefly described along with the meteorological parameters it measures.

  14. Radar Interferometric Observations of Destabilized Rockglaciers

    NASA Astrophysics Data System (ADS)

    Strozzi, Tazio; Delaloye, Reynald; Raetzo, Hugo; Wegmuller, Urs

    2010-03-01

    Analysis of ERS-1/2 Tandem SAR interferograms for inventorying mass wasting in the periglacial belt of the Valais Alps (Switzerland) has evidenced - what was not expected before - that at least 10 rockglaciers were affected by very rapid movements of about 1 cm/day in 1995-1999. Currently, the detection of the state of activity of these very rapidly moving rockglaciers is hardly feasible with satellite SAR data, because of signal decorrelation after the 35, 46 and 11 days repeat intervals of the ENVISAT, ALOS and TerraSAR-X satellites, respectively. The role of space-borne radar interferometry as an element in a warning system is thus insignificant for these very rapid landslides, but an in- situ radar imaging system can overcome some of the limitations of satellite systems. In this contribution we present results from terrestrial radar interferometric measurements of two destabilized rockglaciers performed in August 2009.

  15. Radar data smoothing filter study

    NASA Technical Reports Server (NTRS)

    White, J. V.

    1984-01-01

    The accuracy of the current Wallops Flight Facility (WFF) data smoothing techniques for a variety of radars and payloads is examined. Alternative data reduction techniques are given and recommendations are made for improving radar data processing at WFF. A data adaptive algorithm, based on Kalman filtering and smoothing techniques, is also developed for estimating payload trajectories above the atmosphere from noisy time varying radar data. This algorithm is tested and verified using radar tracking data from WFF.

  16. Systems and Methods for Radar Data Communication

    NASA Technical Reports Server (NTRS)

    Bunch, Brian (Inventor); Szeto, Roland (Inventor); Miller, Brad (Inventor)

    2013-01-01

    A radar information processing system is operable to process high bandwidth radar information received from a radar system into low bandwidth radar information that may be communicated to a low bandwidth connection coupled to an electronic flight bag (EFB). An exemplary embodiment receives radar information from a radar system, the radar information communicated from the radar system at a first bandwidth; processes the received radar information into processed radar information, the processed radar information configured for communication over a connection operable at a second bandwidth, the second bandwidth lower than the first bandwidth; and communicates the radar information from a radar system, the radar information communicated from the radar system at a first bandwidth.

  17. Spaceborne Imaging Radar Symposium

    NASA Technical Reports Server (NTRS)

    Elachi, C.

    1983-01-01

    An overview of the present state of the art in the different scientific and technological fields related to spaceborne imaging radars was presented. The data acquired with the SEASAT SAR (1978) and Shuttle Imaging Radar, SIR-A (1981) clearly demonstrated the important emphasis in the 80's is going to be on in-depth research investigations conducted with the more flexible and sophisticated SIR series instruments and on long term monitoring of geophysical phenomena conducted from free-flying platforms such as ERS-1 and RADARSAT.

  18. Spaceborne laser radar.

    NASA Technical Reports Server (NTRS)

    Flom, T.

    1972-01-01

    Development of laser systems to acquire and track targets in applications such as the rendezvous and docking of two spacecraft. A scan technique is described whereby a narrow laser beam is simultaneously scanned with an equally narrow receiver field-of-view without the aid of mechanical gimbals. Equations are developed in order to examine the maximum acquisition and tracking rates, and the maximum target range for a scanning laser radar system. A recently built prototype of a small, lightweight, low-power-consuming scanning laser radar is described.

  19. Radar Investigations of Asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1984-01-01

    Radar investigations of asteroids, including observations during 1984 to 1985 of at least 8 potential targets and continued analyses of radar data obtained during 1980 to 1984 for 30 other asteroids is proposed. The primary scientific objectives include estimation of echo strength, polarization, spectral shape, spectral bandwidth, and Doppler shift. These measurements yield estimates of target size, shape, and spin vector; place constraints on topography, morphology, density, and composition of the planetary surface; yield refined estimates of target orbital parameters; and reveals the presence of asteroidal satellites.

  20. SEASAT Synthetic Aperture Radar Data

    NASA Technical Reports Server (NTRS)

    Henderson, F. M.

    1981-01-01

    The potential of radar imagery from space altitudes is discussed and the advantages of radar over passive sensor systems are outlined. Specific reference is made to the SEASAT synthetic aperture radar. Possible applications include oil spill monitoring, snow and ice reconnaissance, mineral exploration, and monitoring phenomena in the urban environment.

  1. Side looking radar calibration study

    NASA Technical Reports Server (NTRS)

    Edwards, W. D.

    1975-01-01

    Calibration of an airborne sidelooking radar is accomplished by the use of a model that relates the radar parameters to the physical mapping situation. Topics discussed include: characteristics of the transmitters; the antennas; target absorption and reradiation; the receiver and map making or radar data processing; and the calibration process.

  2. Space Radar Image of Central Sumatra, Indonesia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of the central part of the island of Sumatra in Indonesia that shows how the tropical rainforest typical of this country is being impacted by human activity. Native forest appears in green in this image, while prominent pink areas represent places where the native forest has been cleared. The large rectangular areas have been cleared for palm oil plantations. The bright pink zones are areas that have been cleared since 1989, while the dark pink zones are areas that were cleared before 1989. These radar data were processed as part of an effort to assist oil and gas companies working in the area to assess the environmental impact of both their drilling operations and the activities of the local population. Radar images are useful in these areas because heavy cloud cover and the persistent smoke and haze associated with deforestation have prevented usable visible-light imagery from being acquired since 1989. The dark shapes in the upper right (northeast) corner of the image are a chain of lakes in flat coastal marshes. This image was acquired in October 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour. Environmental changes can be easily documented by comparing this image with visible-light data that were acquired in previous years by the Landsat satellite. The image is centered at 0.9 degrees north latitude and 101.3 degrees east longitude. The area shown is 50 kilometers by 100 kilometers (31 miles by 62 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received; green is L-band horizontally transmitted, vertically received; blue is L-band vertically transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.

  3. Space radar image of Galeras Volcano, Colombia

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This radar image of the area surrounding the Galeras volcano in southern Colombia shows the ability of a multi-frequency radar to map volcanic structures that can be dangerous to study on the ground. Galeras has erupted more than 20 times since the area was first visited by European explorers in the 1500s. Volcanic activity levels have been high in the last five years, including an eruption in January 1993 that killed nine people on a scientific expedition to the volcano summit. Galeras is the light green area near the center of the image. The active cone, with a small summit pit, is the red feature nestled against the lower right edge of the caldera (crater) wall. The city of Pasto, with a population of 300,000, is shown in orange near the bottom of the image, just 8 kilometers (5 miles) from the volcano. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/ X-SAR) aboard the space shuttle Endeavour on its 96th orbit on April 15, 1994. North is toward the upper right. The area shown is 49.1 by 36.0 kilometers (30.5 by 22.3 miles), centered at 1.2 degrees north latitude and 77.4 degrees west longitude. The radar illumination is from the top of the image. The false colors in this image were created using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted, vertically received); blue represents the C-band (horizontally transmitted, vertically received). Galeras is one of 15 volcanoes worldwide that are being monitored by the scientific community as an 'International Decade Volcano' because of the hazard that it represents to the local population.

  4. Design and testing of Ground Penetrating Radar equipment dedicated for civil engineering applications: ongoing activities in Working Group 1 of COST Action TU1208

    NASA Astrophysics Data System (ADS)

    Pajewski, Lara; Manacorda, Guido; Persico, Raffaele

    2015-04-01

    This work aims at presenting the ongoing research activities carried out in Working Group 1 'Novel GPR instrumentation' of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (www.GPRadar.eu). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Working Group 1 (WG1) of the Action focuses on the development of innovative GPR equipment dedicated for civil engineering applications. It includes three Projects. Project 1.1 is focused on the 'Design, realisation and optimisation of innovative GPR equipment for the monitoring of critical transport infrastructures and buildings, and for the sensing of underground utilities and voids.' Project 1.2 is concerned with the 'Development and definition of advanced testing, calibration and stability procedures and protocols, for GPR equipment.' Project 1.3 deals with the 'Design, modelling and optimisation of GPR antennas.' During the first year of the Action, WG1 Members coordinated between themselves to address the state of the art and open problems in the scientific fields identified by the above-mentioned Projects [1, 2]. In carrying our this work, the WG1 strongly benefited from the participation of IDS Ingegneria dei Sistemi, one of the biggest GPR manufacturers, as well as from the contribution of external experts as David J. Daniels and Erica Utsi, sharing with the Action Members their wide experience on GPR technology and methodology (First General Meeting, July 2013). The synergy with WG2 and WG4 of the Action was useful for a deep understanding of the problems, merits and limits of available GPR equipment, as well as to discuss how to quantify the reliability of GPR results. An

  5. Imaging Radar Applications in the Death Valley Region

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.

    1996-01-01

    Death Valley has had a long history as a testbed for remote sensing techniques (Gillespie, this conference). Along with visible-near infrared and thermal IR sensors, imaging radars have flown and orbited over the valley since the 1970's, yielding new insights into the geologic applications of that technology. More recently, radar interferometry has been used to derive digital topographic maps of the area, supplementing the USGS 7.5' digital quadrangles currently available for nearly the entire area. As for their shorter-wavelength brethren, imaging radars were tested early in their civilian history in Death Valley because it has a variety of surface types in a small area without the confounding effects of vegetation. In one of the classic references of these early radar studies, in a semi-quantitative way the response of an imaging radar to surface roughness near the radar wavelength, which typically ranges from about 1 cm to 1 m was explained. This laid the groundwork for applications of airborne and spaceborne radars to geologic problems in and regions. Radar's main advantages over other sensors stems from its active nature- supplying its own illumination makes it independent of solar illumination and it can also control the imaging geometry more accurately. Finally, its long wavelength allows it to peer through clouds, eliminating some of the problems of optical sensors, especially in perennially cloudy and polar areas.

  6. Interception of LPI Radar Signals

    DTIC Science & Technology

    1991-11-01

    AD-A246 315!I! I!! II I’ IIi INTERCEPTION OF LPI RADAR SIGNALS (U) by Jim P.Y. Lee DEFENCE RESEARCH ESTABLISHMENT OTTAWA TECHNICAL NOTE 91-23 Canadd...November 1991Ottawa 92-041269’ 2 2 18 II.2t1111111I 111111! !_ 1+1 efrc nadonds INTERCEPTION OF LPI RADAR SIGNALS (U) by Jim P.Y. Lee Radar E"Sect&ion... radar may employ against current EW receivers. The general conclusion is that it is possible to design a LPI radar which is effective against current

  7. Synthetic Aperture Radar Interferometry

    NASA Technical Reports Server (NTRS)

    Rosen, P. A.; Hensley, S.; Joughin, I. R.; Li, F.; Madsen, S. N.; Rodriguez, E.; Goldstein, R. M.

    1998-01-01

    Synthetic aperture radar interferometry is an imaging technique for measuring the topography of a surface, its changes over time, and other changes in the detailed characteristics of the surface. This paper reviews the techniques of interferometry, systems and limitations, and applications in a rapidly growing area of science and engineering.

  8. Netted LPI RADARs

    DTIC Science & Technology

    2011-09-01

    Characteristics ALQ-172 B-52G/H Self- protection Track/search radar jamming, steerable jam beams , software programmable, phased array antenna ...bore sight: knowing the pattern of the antenna’s gain, two or more intercepts within the antenna main beam are sufficient to determine the...14 a. Low Level Antenna Sidelobes .............14 b. Antenna Scan Patterns ...................18 4. Carrier Frequency Selection

  9. Rain radar instrument definition

    NASA Astrophysics Data System (ADS)

    Vincent, Nicolas; Chenebault, J.; Suinot, Noel; Mancini, Paolo L.

    1996-12-01

    As a result of a pre-phase a study, founded by ESA, this paper presents the definition of a spaceborne Rain Radar, candidate instrument for earth explorer precipitation mission. Based upon the description of user requirements for such a dedicated mission, a mission analysis defines the most suitable space segment. At system level, a parametric analysis compares pros and cons of instrument concepts associated with rain rate retrieval algorithms in order to select the most performing one. Several trade-off analysis at subsystem level leads then to the definition of the proposed design. In particular, as pulse compression is implemented in order to increase the radar sensitivity, the selected method to achieve a pulse response with a side-lobe level below--60 dB is presented. Antenna is another critical rain radar subsystem and several designs are com pared: direct radiating array, single or dual reflector illuminated by single or dual feed arrays. At least, feasibility of centralized amplification using TWTA is compared with criticality of Tx/Rx modules for distributed amplification. Mass and power budgets of the designed instrument are summarized as well as standard deviations and bias of simulated rain rate retrieval profiles. The feasibility of a compliant rain radar instrument is therefore demonstrated.

  10. Frequency Diverse Array Radar

    DTIC Science & Technology

    2010-09-01

    the methods for electronic scanning of antenna systems. Techniques that have been studied in this connection include frequency variation, phase shift...an array antenna instantaneously into a desired direction where no mechanical mechanism is involved in the scanning process. Electronic scanning... methods including phase scanning, time delay scanning, and frequency scanning have been used in various radar applications; however new and cheaper

  11. Passive MIMO Radar Detection

    DTIC Science & Technology

    2013-09-01

    Hypothesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 3.3.3 Dependence on SNR...71 4.3.3 Dependence on SNR and DNR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 4.4 Interpretations...described as a passive radar network. The topology of such networks is described as bistatic, multistatic, or multiple-input multiple-output, depending on

  12. Passive bistatic radar analysis

    NASA Astrophysics Data System (ADS)

    O'Hagan, Daniel W.; Kuschel, H.; Schiller, Joachim

    2009-06-01

    Passive Bistatic Radar (PBR) research is at its zenith with several notable PBR systems currently operational, or available for deployment. Such PBRs include the Manastash Ridge Radar (MRR) developed for and by academia; Silent Sentry developed as a commercial concern by Lockheed Martin; and Homeland Alerter (HA100) also a commercial system developed by Thales. However at present, despite the existence of numerous PBR prototypes, take up of commercial passive radar technology remains slow. This is due in part to technology immaturity, in part to politics, and particularly due to the fact that monostatic radars perform so well. If PBRs are to enjoy longevity as a viable technology then it is imperative that they address certain niche application areas, with the aforementioned MRR being one prime example of this. The focus of this paper will be an analysis of a PBR system that utilised FM radio signals of opportunity to detect aircraft targets with an RCS generally not lower than 20 m2. The paper will demonstrate the theoretical detection coverage of an FM based PBR operating in a severe interference environment.

  13. Impulse radar studfinder

    DOEpatents

    McEwan, T.E.

    1995-10-10

    An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes. 9 figs.

  14. Impulse radar studfinder

    DOEpatents

    McEwan, Thomas E.

    1995-01-01

    An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes.

  15. Spear Phishing Attack Detection

    DTIC Science & Technology

    2011-03-24

    types: Windows Portable Executable and Common Object File Format (PE/ COFF ), Adobe Reader, and Microsoft Excel, Word, and PowerPoint. SPEAD’s malware...in PE/ COFF malware detection with an overall accuracy of 99.68% and an accuracy of 98.2% where new malware is involved. Additionally, SPEAD is...viii 4.2.2 Comparing File Detection Metrics ................................................ 73 4.2.2.1 PE/ COFF Malware Detection Results

  16. Toward A Research Framework to Bridge Cross-platform Error Characterization of Spaceborne Passive/Active Sensors using NOAA/NSSL Ground Radar-based National Mosaic QPE Products over CONUS

    NASA Astrophysics Data System (ADS)

    Kirstetter, P.; Hong, Y.; Gourley, J. J.; Cao, Q.; Schwaller, M.; Petersen, W. A.; Zhang, J.; Anagnostou, E. N.; Maggioni, V.; Seyyedi, H.; Chen, S.

    2012-12-01

    A characterization of the error associated to satellite rainfall estimates arises as major information for applications in evolving from deterministic to probabilistic frameworks. We focus here on the error structure of TRMM Precipitation Radar (PR) and Microwave Imager (TMI) quantitative precipitation estimation (QPE) at ground, a major issue for applications of derived products in rainfall estimation from space, water budget studies and hydrological modeling. Due to the variety of sources of error in spaceborne QPE the problem is addressed by comparison of satellite QPEs with reference values derived from ground-based measurements using NOAA/NSSL Ground Radar-based National Mosaic QPE (NMQ). Investigations have been carried out at fine scale (e.g. instantaneous and 5 km for PR) on the basis of several month data samples that explore the effects of regional climatology of the southern part of US. A significant effort has been carried out to derive a trustworthy reference rainfall from bias-corrected NMQ at fine spatial and temporal scales. A comparison framework has been developed to examine the consistency of the ground and space-based sensors in term of precipitation detection, characterization (e.g. convective, stratiform) and quantification. Specific error factors for passive (e.g. surface conditions for TMI) and active (e.g. attenuation of the radar signal, non uniform beam filling for PR) sensors are investigated. Systematic biases and random errors quantified at the satellite estimation scale are useful for satellite-based rainfall products. This cross-platform error characterization will ultimately act as a bridge to intercalibrate active and passive microwave measurements from the GPM core satellite to the constellation satellites.

  17. Space Radar Image of Reunion Island

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the volcanic island of Reunion, about 700 km (434 miles) east of Madagascar in the southwest Indian Ocean. The southern half of the island is dominated by the active volcano, Piton de la Fournaise. This is one of the world's most active volcanoes, with more than 100 eruptions in the last 300 years. The most recent activity occurred in the vicinity of Dolomieu Crater, shown in the lower center of the image within a horseshoe-shaped collapse zone. Recent lava flows appear in shades of red, purple and orange. Light green areas are heavily vegetated forest, while much of the purple area near the coast is farmland. The radar illumination is from the left side of the image and dramatically emphasizes the precipitous cliffs at the edges of the central canyons of the island. These canyons are remnants from the collapse of formerly active parts of the volcanoes that built the island. This image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on October 5, 1994. The image is centered at 21.2 degrees south latitude, 55.6 degrees east longitude. The area shown is approximately 50 km by 80 km (31 miles by 50 miles). North is toward the upper right. Colors are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, vertically received; green is L-band horizontally transmitted, vertically received; and blue is C-band horizontally transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth.

  18. Progress in coherent laser radar

    NASA Technical Reports Server (NTRS)

    Vaughan, J. M.

    1986-01-01

    Considerable progress with coherent laser radar has been made over the last few years, most notably perhaps in the available range of high performance devices and components and the confidence with which systems may now be taken into the field for prolonged periods of operation. Some of this increasing maturity was evident at the 3rd Topical Meeting on Coherent Laser Radar: Technology and Applications. Topics included in discussions were: mesoscale wind fields, nocturnal valley drainage and clear air down bursts; airborne Doppler lidar studies and comparison of ground and airborne wind measurement; wind measurement over the sea for comparison with satellite borne microwave sensors; transport of wake vortices at airfield; coherent DIAL methods; a newly assembled Nd-YAG coherent lidar system; backscatter profiles in the atmosphere and wavelength dependence over the 9 to 11 micrometer region; beam propagation; rock and soil classification with an airborne 4-laser system; technology of a global wind profiling system; target calibration; ranging and imaging with coherent pulsed and CW system; signal fluctuations and speckle. Some of these activities are briefly reviewed.

  19. Space Radar Image of Mt. Etna, Italy

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The summit of the Mount Etna volcano on the island of Sicily, Italy, one of the most active volcanoes in the world, is shown near the center of this radar image. Lava flows of different ages and surface roughness appear in shades of purple, green, yellow and pink surrounding the four small craters at the summit. Etna is one of the best-studied volcanoes in the world and scientists are using this radar image to identify and distinguish a variety of volcanic features. Etna has erupted hundreds of times in recorded history, with the most recent significant eruption in 1991-1993. Scientists are studying Etna as part of the international 'Decade Volcanoes' project, because of its high level of activity and potential threat to local populations. This image was acquired on October 11, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. The image is centered at 37.8 degrees North latitude and 15.1 degrees East longitude and covers an area of 51.2 kilometers by 22.6 kilometers (31.7 miles by 14.0 miles).

  20. Evaluation of radar imagery for geological and cartographic applications

    USGS Publications Warehouse

    Moore, Gerald K.; Sheehan, Cynthia A.

    1981-01-01

    The House/Senate conference report on H.R. 4930 (96th Congress), the Department of the Interior and Related Agencies Appropriations bill, 1980, stated that the U.S. Geological Survey should "begin the use of side-looking airborne radar imagery for topographic and geological mapping, and geological resource surveys in promising areas, particularly Alaska." In response to this mandate, the Survey acquired radar data and began scientific studies to analyze and interpret these data. About 70 percent of the project funding was used to acquire radar imagery and to evaluate Alaskan applications. Results of these studies indicate that radar images have a unique incremental value for certain geologic and cartographic applications but that the images are best suited for use as supplemental information sources or as primary data sources in areas of persistent cloud cover.The value of radar data is greatest for geologic mapping and resource surveys, particularly for mineral and petroleum exploration, where the objective is to locate any single feature or group of features that may control the occurrences of these resources. Radar images are considered by oil and gas companies to be worth the cost of data acquisition within a limited area of active exploration.Radar images also have incremental value for geologic site studies and hazard mapping. The need in these cases is TO inventory all geologic hazards to human life, property, resources, and the environment. For other geologic applications, radar images have a relatively small incremental value over a combination of Landsat images and aerial photographs.The value of radar images for cartographic applications is minimal, except when they are used as a substitute for aerial photographs and topographic maps in persistently cloud-covered areas. If conventional data sources are not available, radar images provide useful information on terrain relief, landforms, drainage patterns, and land cover. Screen less lithography is a low

  1. Space Radar Image of Raco Biomass Map

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This biomass map of the Raco, Michigan, area was produced from data acquired by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard space shuttle Endeavour. Biomass is the amount of plant material on an area of Earth's surface. Radar can directly sense the quantity and organizational structure of the woody biomass in the forest. Science team members at the University of Michigan used the radar data to estimate the standing biomass for this Raco site in the Upper Peninsula of Michigan. Detailed surveys of 70 forest stands will be used to assess the accuracy of these techniques. The seasonal growth of terrestrial plants, and forests in particular, leads to the temporary storage of large amounts of carbon, which could directly affect changes in global climate. In order to accurately predict future global change, scientists need detailed information about current distribution of vegetation types and the amount of biomass present around the globe. Optical techniques to determine net biomass are frustrated by chronic cloud-cover. Imaging radar can penetrate through cloud-cover with negligible signal losses. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German

  2. Space Radar Image of San Francisco, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of San Francisco, California, taken on October 3,1994. The image is about 40 kilometers by 55 kilometers (25 miles by 34 miles) with north toward the upper right. Downtown San Francisco is visible in the center of the image with the city of Oakland east (to the right) across San Francisco Bay. Also visible in the image is the Golden Gate Bridge (left center) and the Bay Bridge connecting San Francisco and Oakland. North of the Bay Bridge is Treasure Island. Alcatraz Island appears as a small dot northwest of Treasure Island. This image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on orbit 56. The image is centered at 37 degrees north latitude, 122degrees west longitude. This single-frequency SIR-C image was obtained by the L-band (24 cm) radar channel, horizontally transmitted and received. Portions of the Pacific Ocean visible in this image appear very dark as do other smooth surfaces such as airport runways. Suburban areas, with the low-density housing and tree-lined streets that are typical of San Francisco, appear as lighter gray. Areas with high-rise buildings, such as those seen in the downtown areas, appear in very bright white, showing a higher density of housing and streets which run parallel to the radar flight track. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: the L-band (24 cm), C-band (6 cm) and X-band (3cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes

  3. An MSK Radar Waveform

    NASA Technical Reports Server (NTRS)

    Quirk, Kevin J.; Srinivasan, Meera

    2012-01-01

    The minimum-shift-keying (MSK) radar waveform is formed by periodically extending a waveform that separately modulates the in-phase and quadrature- phase components of the carrier with offset pulse-shaped pseudo noise (PN) sequences. To generate this waveform, a pair of periodic PN sequences is each passed through a pulse-shaping filter with a half sinusoid impulse response. These shaped PN waveforms are then offset by half a chip time and are separately modulated on the in-phase and quadrature phase components of an RF carrier. This new radar waveform allows an increase in radar resolution without the need for additional spectrum. In addition, it provides self-interference suppression and configurable peak sidelobes. Compared strictly on the basis of the expressions for delay resolution, main-lobe bandwidth, effective Doppler bandwidth, and peak ambiguity sidelobe, it appears that bi-phase coded (BPC) outperforms the new MSK waveform. However, a radar waveform must meet certain constraints imposed by the transmission and reception of the modulation, as well as criteria dictated by the observation. In particular, the phase discontinuity of the BPC waveform presents a significant impediment to the achievement of finer resolutions in radar measurements a limitation that is overcome by using the continuous phase MSK waveform. The phase continuity, and the lower fractional out-of-band power of MSK, increases the allowable bandwidth compared with BPC, resulting in a factor of two increase in the range resolution of the radar. The MSK waveform also has been demonstrated to have an ambiguity sidelobe structure very similar to BPC, where the sidelobe levels can be decreased by increasing the length of the m-sequence used in its generation. This ability to set the peak sidelobe level is advantageous as it allows the system to be configured to a variety of targets, including those with a larger dynamic range. Other conventionally used waveforms that possess an even greater

  4. Radar Target Recognition Using Bispectrum Correlation

    DTIC Science & Technology

    2007-06-01

    21 2. Inverse Synthetic Aperture Radar ...................................................22 3. Range Profiles...characteristics need to be stored. 2. Inverse Synthetic Aperture Radar We often identify things based on pictures and Synthetic Aperture Radar (SAR) is an...By taking multiple discrete measurements while translating the radar , a larger effective aperture can be created. Inverse Synthetic Aperture Radar

  5. 51. View of upper radar scanner switch in radar scanner ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. View of upper radar scanner switch in radar scanner building 105 from upper catwalk level showing emanating waveguides from upper switch (upper one-fourth of photograph) and emanating waveguides from lower radar scanner switch in vertical runs. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  6. Radar cross-sectional study using noise radar

    NASA Astrophysics Data System (ADS)

    Freundorfer, A. P.; Siddiqui, J. Y.; Antar, Y. M. M.

    2015-05-01

    A noise radar system is proposed with capabilities to measure and acquire the radar cross-section (RCS) of targets. The proposed system can cover a noise bandwidth of near DC to 50 GHz. The noise radar RCS measurements were conducted for selective targets like spheres and carpenter squares with and without dielectric bodies for a noise band of 400MHz-5000MHz. The bandwidth of operation was limited by the multiplier and the antennae used.

  7. 41. Perimeter acquisition radar building radar element and coaxial display, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. Perimeter acquisition radar building radar element and coaxial display, with drawing of typical antenna section. Drawing, from left to right, shows element, aluminum ground plane, cable connectors and hardware, cable, and back-up ring. Grey area is the concrete wall - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  8. Kuiper Belt Mapping Radar

    NASA Technical Reports Server (NTRS)

    Freeman, A.; Nilsen, E.

    2001-01-01

    Since their initial discovery in 1992, to date only a relatively small number of Kuiper Belt Objects (KBO's) have been discovered. Current detection techniques rely on frame-to-frame comparisons of images collected by optical telescopes such as Hubble, to detect KBO's as they move against the background stellar field. Another technique involving studies of KBO's through occultation of known stars has been proposed. Such techniques are serendipitous, not systematic, and may lead to an inadequate understanding of the size, range, and distribution of KBO's. In this paper, a future Kuiper Belt Mapping Radar is proposed as a solution to the problem of mapping the size distribution, extent, and range of KBO's. This approach can also be used to recover radar albedo and object rotation rates. Additional information is contained in the original extended abstract.

  9. RADAR Reveals Titan Topography

    NASA Technical Reports Server (NTRS)

    Kirk, R. L.; Callahan, P.; Seu, R.; Lorenz, R. D.; Paganelli, F.; Lopes, R.; Elachi, C.

    2005-01-01

    The Cassini Titan RADAR Mapper is a K(sub u)-band (13.78 GHz, lambda = 2.17 cm) linear polarized RADAR instrument capable of operating in synthetic aperture (SAR), scatterometer, altimeter and radiometer modes. During the first targeted flyby of Titan on 26 October, 2004 (referred to as Ta) observations were made in all modes. Evidence for topographic relief based on the Ta altimetry and SAR data are presented here. Additional SAR and altimetry observations are planned for the T3 encounter on 15 February, 2005, but have not been carried out at this writing. Results from the T3 encounter relevant to topography will be included in our presentation. Data obtained in the Ta encounter include a SAR image swath

  10. Floor-plan radar

    NASA Astrophysics Data System (ADS)

    Falconer, David G.; Ueberschaer, Ronald M.

    2000-07-01

    Urban-warfare specialists, law-enforcement officers, counter-drug agents, and counter-terrorism experts encounter operational situations where they must assault a target building and capture or rescue its occupants. To minimize potential casualties, the assault team needs a picture of the building's interior and a copy of its floor plan. With this need in mind, we constructed a scale model of a single- story house and imaged its interior using synthetic-aperture techniques. The interior and exterior walls nearest the radar set were imaged with good fidelity, but the distal ones appear poorly defined and surrounded by ghosts and artifacts. The latter defects are traceable to beam attenuation, wavefront distortion, multiple scattering, traveling waves, resonance phenomena, and other effects not accounted for in the traditional (noninteracting, isotropic point scatterer) model for radar imaging.

  11. Observability of NEIALs with the Sondrestrom and Poker Flat incoherent scatter radars

    NASA Astrophysics Data System (ADS)

    Michell, R. G.; Samara, M.

    2013-12-01

    We present coordinated optical and radar observations using the Poker Flat Incoherent Scatter Radar (PFISR) in Alaska and the Sondrestrom radar in Greenland. Several cases were examined where intense, similar-looking dynamic auroral structures were observed in the magnetic zenith. The presence or absence of Naturally Enhanced Ion Acoustic Lines (NEIALs) was investigated in both sets of radar data. In all cases, the aurora exhibited small-scale (∼0.1-1 km), dynamic features that were observed with both all-sky and narrow-field of view (19°) imagers. In all of the cases examined, the PFISR radar observed NEIALs while the Sondrestrom radar did not, despite similar auroral morphology. The main difference between the radars, namely the probing wave number, provides strong evidence for a limiting spatial scale of between 10 and 15 cm for the enhanced wave activity responsible for NEIALs. This has implications for constraining the models of NEIAL generation mechanisms.

  12. Spaceborne Radar Study

    DTIC Science & Technology

    1974-06-28

    If comm beam contact is lost, the instrumentation data are sent via the omnichannel transmitter on command of the ground station. There are six ways...comm’beam) at all times except when comm beam contact is lost. A two-way omnidirectional (backup) command link is provided for initial stabilization...via either the oomm beam or the omnichannel . Satellite instrumentation data are sent to the ground station following every radar signal transmission

  13. Shuttle imaging radar experiment

    USGS Publications Warehouse

    Elachi, C.; Brown, W.E.; Cimino, J.B.; Dixon, T.; Evans, D.L.; Ford, J.P.; Saunders, R.S.; Breed, C.; Masursky, H.; McCauley, J.F.; Schaber, G.; Dellwig, L.; England, A.; MacDonald, H.; Martin-Kaye, P.; Sabins, F.

    1982-01-01

    The shuttle imaging radar (SIR-A) acquired images of a variety of the earth's geologic areas covering about 10 million square kilometers. Structural and geomorphic features such as faults, folds, outcrops, and dunes are clearly visible in both tropical and arid regions. The combination of SIR-A and Seasat images provides additional information about the surface physical properties: topography and roughness. Ocean features were also observed, including large internal waves in the Andaman Sea. Copyright ?? 1982 AAAS.

  14. Weather Radar Studies.

    DTIC Science & Technology

    2014-09-26

    and Doppler weather radar data from the National Center for Atmospheric Research JAWS program and the National .Severe Storms Laboratory, are being...Atmospheric Research JAWS program and the National Severe Storms Laboratory, are being analyzed to develop low-altitude wind-shear detection algorithms...pictures, and dusted for fingerprints. The wind sensors, rain gauge, and antenna were destroyed but the DCP, solar panel, and other site components

  15. The Radar Roadmap

    DTIC Science & Technology

    2013-01-01

    LIMITATION OF ABSTRACT Same as Report ( SAR ) 18. NUMBER OF PAGES 25 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c...ABSTRACT Same as Report ( SAR ) 18. NUMBER OF PAGES 25 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE...object bistatic radars. The former allows high resolution without the use of pulse compression techniques and the latter promises cheaper systems by

  16. Imaging synthetic aperture radar

    DOEpatents

    Burns, Bryan L.; Cordaro, J. Thomas

    1997-01-01

    A linear-FM SAR imaging radar method and apparatus to produce a real-time image by first arranging the returned signals into a plurality of subaperture arrays, the columns of each subaperture array having samples of dechirped baseband pulses, and further including a processing of each subaperture array to obtain coarse-resolution in azimuth, then fine-resolution in range, and lastly, to combine the processed subapertures to obtain the final fine-resolution in azimuth. Greater efficiency is achieved because both the transmitted signal and a local oscillator signal mixed with the returned signal can be varied on a pulse-to-pulse basis as a function of radar motion. Moreover, a novel circuit can adjust the sampling location and the A/D sample rate of the combined dechirped baseband signal which greatly reduces processing time and hardware. The processing steps include implementing a window function, stabilizing either a central reference point and/or all other points of a subaperture with respect to doppler frequency and/or range as a function of radar motion, sorting and compressing the signals using a standard fourier transforms. The stabilization of each processing part is accomplished with vector multiplication using waveforms generated as a function of radar motion wherein these waveforms may be synthesized in integrated circuits. Stabilization of range migration as a function of doppler frequency by simple vector multiplication is a particularly useful feature of the invention; as is stabilization of azimuth migration by correcting for spatially varying phase errors prior to the application of an autofocus process.

  17. Goldstone solar system radar

    NASA Technical Reports Server (NTRS)

    Jurgens, Raymond F.

    1991-01-01

    Caltech/Jet Propulsion Laboratory (JPL) radar astronomers made use of the Very Large Array (VLA) at Socorro, NM, during February 1990, to receive radio echoes from the planet Venus. The transmitter was the 70 meter antenna at the Goldstone complex northwest of Barstow, CA. These observations contain new information about the roughness of Venus at cm to decimeter scales and are complementary to information being obtained by the Magellan spacecraft. Asteroid observations are also discussed.

  18. Weather Radar Studies.

    DTIC Science & Technology

    1985-03-31

    National Center for Atmospheric Research JAWS program and the National Severe Storms Laboratory are being analyzed to develop low-altitude wind shear...public through low-altitude wind shear aviation weather products the National Technical Information Service, NEXR I turbulence., Springfield, VA 22161. 19...were analyzed preliminarily to determine wind shear characteristics in the Memphis area. Doppler weather radar data from the National Center for

  19. Space Radar Image of Tuva, Central Asia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image shows part of the remote central Asian region of Tuva, an autonomous republic of the Russian Federation. Tuva is a mostly mountainous region that lies between western Mongolia and southern Siberia. This image shows the area just south of the republic's capital of Kyzyl. Most of the red, pink and blue areas in the image are agricultural fields of a large collective farming complex that was developed during the era of the Soviet Union. Traditional agricultural activity in the region, still active in remote areas, revolves around practices of nomadic livestock herding. White areas on the image are north-facing hillsides, which develop denser forests than south-facing slopes. The river in the upper right is one of the two major branches of the Yenesey River. Tuva has received some notoriety in recent years due to the intense interest of the celebrated Caltech physicist Dr. Richard Feynman, chronicled in the book 'Tuva or Bust' by Ralph Leighton. The image was acquired by Spaceborne Imaging Radar-C/X-Band SyntheticAperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour onOctober 1, 1994. The image is 56 kilometers by 74 kilometers (35 miles by 46 miles) and is centered at 51.5 degrees north latitude, 95.1 degrees east longitude. North is toward the upper right. The colors are assigned to different radar fequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted andreceived; green is L-band, horizontally transmitted and vertically received; and blue is C-band, horizontally transmitted and verticallyreceived. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to PlanetEarth program.

  20. Radar clutter classification

    NASA Astrophysics Data System (ADS)

    Stehwien, Wolfgang

    1989-11-01

    The problem of classifying radar clutter as found on air traffic control radar systems is studied. An algorithm based on Bayes decision theory and the parametric maximum a posteriori probability classifier is developed to perform this classification automatically. This classifier employs a quadratic discriminant function and is optimum for feature vectors that are distributed according to the multivariate normal density. Separable clutter classes are most likely to arise from the analysis of the Doppler spectrum. Specifically, a feature set based on the complex reflection coefficients of the lattice prediction error filter is proposed. The classifier is tested using data recorded from L-band air traffic control radars. The Doppler spectra of these data are examined; the properties of the feature set computed using these data are studied in terms of both the marginal and multivariate statistics. Several strategies involving different numbers of features, class assignments, and data set pretesting according to Doppler frequency and signal to noise ratio were evaluated before settling on a workable algorithm. Final results are presented in terms of experimental misclassification rates and simulated and classified plane position indicator displays.

  1. Motion measurement for synthetic aperture radar

    SciTech Connect

    Doerry, Armin W.

    2015-01-01

    Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3-D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract AC04-94AL85000.

  2. Space Radar Image of Los Angeles, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    -C/X-SAR, scientists will be able to discern these areas even more clearly. Space Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: the L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  3. High-resolution instrumentation radar

    NASA Astrophysics Data System (ADS)

    Dydbal, Robert B.; Hurlbut, Keith H.; Mori, Tsutomu T.

    1987-03-01

    An instrumentation radar that uses a chirp waveform to achieve high-range resolution is described. High-range-resolution instrumentation radars evaluate the target response to operational waveforms used in high-performance radars and/or obtain a display of the individual target scattering mechanisms to better understand the scattering process. This particular radar was efficiently constructed from a combination of commercially available components and in-house fabricated circuitry. This instrumentation radar operates at X-band and achieves a 4.9-in-range resolution. A key feature of the radar is the combination of amplitude weighting with a high degree of waveform fidelity to achieve a very good range sidelobe performance. This range sidelobe performance is important to avoid masking lower level target returns in the range sidelobes of higher target returns.

  4. Space Radar Image of Chernobyl

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of the Chernobyl nuclear power plant and its surroundings, centered at 51.17 north latitude and 30.15 west longitude. The image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on its 16th orbit on October 1, 1994. The area is located on the northern border of the Ukraine Republic and was produced by using the L-band (horizontally transmitted and received) polarization. The differences in the intensity are due to differences in vegetation cover, with brighter areas being indicative of more vegetation. These data were acquired as part of a collaboration between NASA and the National Space Agency of Ukraine in Remote Sensing and Earth Sciences. NASA has included several sites provided by the Ukrainian space agency as targets of opportunity during the second flight of SIR-C/X-SAR. The Ukrainian space agency also plans to conduct airborne surveys of these sites during the mission. The Chernobyl nuclear power plant is located toward the top of the image near the Pripyat River. The 12-kilometer (7.44-mile)-long cooling pond is easily distinguishable as an elongated dark shape in the center near the top of the image. The reactor complex is visible as the bright area to the extreme left of the cooling pond and the city of Chernobyl is the bright area just below the cooling pond next to the Pripyat River. The large dark area in the bottom right of the image is the Kiev Reservoir just north of Kiev. Also visible is the Dnieper River, which feeds into the Kiev Reservoir from the top of the image. The Soviet government evacuated 116,000 people within 30 kilometers (18.6 miles) of the Chernobyl reactor after the explosion and fire on April 26, 1986. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight

  5. High-resolution three-dimensional imaging radar

    NASA Technical Reports Server (NTRS)

    Cooper, Ken B. (Inventor); Chattopadhyay, Goutam (Inventor); Siegel, Peter H. (Inventor); Dengler, Robert J. (Inventor); Schlecht, Erich T. (Inventor); Mehdi, Imran (Inventor); Skalare, Anders J. (Inventor)

    2010-01-01

    A three-dimensional imaging radar operating at high frequency e.g., 670 GHz, is disclosed. The active target illumination inherent in radar solves the problem of low signal power and narrow-band detection by using submillimeter heterodyne mixer receivers. A submillimeter imaging radar may use low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform. Three-dimensional images are generated through range information derived for each pixel scanned over a target. A peak finding algorithm may be used in processing for each pixel to differentiate material layers of the target. Improved focusing is achieved through a compensation signal sampled from a point source calibration target and applied to received signals from active targets prior to FFT-based range compression to extract and display high-resolution target images. Such an imaging radar has particular application in detecting concealed weapons or contraband.

  6. Space Radar Image of Bahia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    . The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI) with the Deutsche Forschungsanstalt fuer luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  7. Radar-aeolian roughness project

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Dobrovolskis, A.; Gaddis, L.; Iversen, J. D.; Lancaster, N.; Leach, Rodman N.; Rasnussen, K.; Saunders, S.; Vanzyl, J.; Wall, S.

    1991-01-01

    The objective is to establish an empirical relationship between measurements of radar, aeolian, and surface roughness on a variety of natural surfaces and to understand the underlying physical causes. This relationship will form the basis for developing a predictive equation to derive aeolian roughness from radar backscatter. Results are given from investigations carried out in 1989 on the principal elements of the project, with separate sections on field studies, radar data analysis, laboratory simulations, and development of theory for planetary applications.

  8. Radar studies of bird migration

    NASA Technical Reports Server (NTRS)

    Williams, T. C.; Williams, J. M.

    1974-01-01

    Observations of bird migration with NASA radars were made at Wallops Island, Va. Simultaneous observations were made at a number of radar sites in the North Atlantic Ocean in an effort to discover what happened to those birds that were observed leaving the coast of North America headed toward Bermuda, the Caribbean and South America. Transatlantic migration, utilizing observations from a large number of radars is discussed. Detailed studies of bird movements at Wallops Island are presented.

  9. Radar Studies of Aviation Hazards

    DTIC Science & Technology

    1994-05-31

    4. TITLE AND SURTITLE S. FUNDING NUMBERS RADAR STUDIES OF AVIATION HAZARDS F1 9628-93- C -0054 _____________ __PE63707F 6. AUTHOR(S) PR278 1...foilowing processing steps have been adopted: a. acquire single scan radar data, b. distinguish individual storms, c . eliminate spurious data for...occurred only with radar reflectivities above 40 dBZ at the -10° C level and cloud tops above the -200C level. Lightning occurred only when tops extended

  10. Active microwave remote sensing research program plan. Recommendations of the Earth Resources Synthetic Aperture Radar Task Force. [application areas: vegetation canopies, surface water, surface morphology, rocks and soils, and man-made structures

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A research program plan developed by the Office of Space and Terrestrial Applications to provide guidelines for a concentrated effort to improve the understanding of the measurement capabilities of active microwave imaging sensors, and to define the role of such sensors in future Earth observations programs is outlined. The focus of the planned activities is on renewable and non-renewable resources. Five general application areas are addressed: (1) vegetation canopies, (2) surface water, (3) surface morphology, (4) rocks and soils, and (5) man-made structures. Research tasks are described which, when accomplished, will clearly establish the measurement capabilities in each area, and provide the theoretical and empirical results needed to specify and justify satellite systems using imaging radar sensors for global observations.

  11. Underwater probing with laser radar

    NASA Technical Reports Server (NTRS)

    Carswell, A. I.; Sizgoric, S.

    1975-01-01

    Recent advances in laser and electro optics technology have greatly enhanced the feasibility of active optical probing techniques aimed at the remote sensing of water parameters. This paper describes a LIDAR (laser radar) that has been designed and constructed for underwater probing. The influence of the optical properties of water on the general design parameters of a LIDAR system is considered. Discussion of the specific details in the choice of the constructed LIDAR is given. This system utilizes a cavity dumped argon ion laser transmitter capable of 50 watt peak powers, 10 nanosecond pulses and megahertz pulse repetition rates at 10 different wavelengths in the blue green region of the spectrum. The performance of the system, in proving various types of water, is demonstrated by summarizing the results of initial laboratory and field experiments.

  12. Application of Interferometric Radars to Planetary Geologic Studies

    NASA Technical Reports Server (NTRS)

    Mouginis-Mark, P. J.; Rosen, P.; Freeman, A.

    2005-01-01

    Radar interferometry is rapidly becoming one of the major applications of radar systems in Earth orbit. So far the 2000 flight of the Shuttle Radar Topographic Mission (SRTM) is the only dedicated U.S. radar to be flown for the collection of interferometric data, but enough has been learned from this mission and from the use of foreign partner radars (ERS-1/2, Radarsat, ENIVISAT and JERS-1) for the potential planetary applications of this technique to be identified. A recent workshop was organized by the Jet Propulsion Laboratory and the Southern California Earthquake Center (SCEC), and was held at Oxnard, CA, from October 20th - 22nd, 2004. At this meeting, the major interest was in terrestrial radar systems, but approx. 20 or the approx. 250 attendees also discussed potential applications of interferometric radar for the terrestrial planets. The primary foci were for the detection of planetary water, the search for active tectonism and volcanism and the improved topographic mapping. This abstract provides a summary of these planetary discussions at the Oxnard meeting.

  13. Reconfigurable L-Band Radar

    NASA Technical Reports Server (NTRS)

    Rincon, Rafael F.

    2008-01-01

    The reconfigurable L-Band radar is an ongoing development at NASA/GSFC that exploits the capability inherently in phased array radar systems with a state-of-the-art data acquisition and real-time processor in order to enable multi-mode measurement techniques in a single radar architecture. The development leverages on the L-Band Imaging Scatterometer, a radar system designed for the development and testing of new radar techniques; and the custom-built DBSAR processor, a highly reconfigurable, high speed data acquisition and processing system. The radar modes currently implemented include scatterometer, synthetic aperture radar, and altimetry; and plans to add new modes such as radiometry and bi-static GNSS signals are being formulated. This development is aimed at enhancing the radar remote sensing capabilities for airborne and spaceborne applications in support of Earth Science and planetary exploration This paper describes the design of the radar and processor systems, explains the operational modes, and discusses preliminary measurements and future plans.

  14. Python-ARM Radar Toolkit

    SciTech Connect

    Jonathan Helmus, Scott Collis

    2013-03-17

    The Python-ARM Radar Toolkit (Py-ART) is a collection of radar quality control and retrieval codes which all work on two unifying Python objects: the PyRadar and PyGrid objects. By building ingests to several popular radar formats and then abstracting the interface Py-ART greatly simplifies data processing over several other available utilities. In addition Py-ART makes use of Numpy arrays as its primary storage mechanism enabling use of existing and extensive community software tools.

  15. The 3D laser radar vision processor system

    NASA Technical Reports Server (NTRS)

    Sebok, T. M.

    1990-01-01

    Loral Defense Systems (LDS) developed a 3D Laser Radar Vision Processor system capable of detecting, classifying, and identifying small mobile targets as well as larger fixed targets using three dimensional laser radar imagery for use with a robotic type system. This processor system is designed to interface with the NASA Johnson Space Center in-house Extra Vehicular Activity (EVA) Retriever robot program and provide to it needed information so it can fetch and grasp targets in a space-type scenario.

  16. Millimeter Wave Cloud Radar (MMCR) Handbook

    SciTech Connect

    KB Widener; K Johnson

    2005-01-30

    The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.

  17. Space Radar Image of Manaus, Brazil

    NASA Technical Reports Server (NTRS)

    1999-01-01

    These two images were created using data from the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). On the left is a false-color image of Manaus, Brazil acquired April 12, 1994, onboard space shuttle Endeavour. In the center of this image is the Solimoes River just west of Manaus before it combines with the Rio Negro to form the Amazon River. The scene is around 8 by 8 kilometers (5 by 5 miles) with north toward the top. The radar image was produced in L-band where red areas correspond to high backscatter at HH polarization, while green areas exhibit high backscatter at HV polarization. Blue areas show low backscatter at VV polarization. The image on the right is a classification map showing the extent of flooding beneath the forest canopy. The classification map was developed by SIR-C/X-SAR science team members at the University of California,Santa Barbara. The map uses the L-HH, L-HV, and L-VV images to classify the radar image into six categories: Red flooded forest Green unflooded tropical rain forest Blue open water, Amazon river Yellow unflooded fields, some floating grasses Gray flooded shrubs Black floating and flooded grasses Data like these help scientists evaluate flood damage on a global scale. Floods are highly episodic and much of the area inundated is often tree-covered. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those

  18. Synthetic aperture radar interferometry of Okmok volcano, Alaska: radar observations

    USGS Publications Warehouse

    Lu, Zhong; Mann, Dörte; Freymueller, Jeffrey T.; Meyer, David

    2000-01-01

    ERS-1/ERS-2 synthetic aperture radar interferometry was used to study the 1997 eruption of Okmok volcano in Alaska. First, we derived an accurate digital elevation model (DEM) using a tandem ERS-1/ERS-2 image pair and the preexisting DEM. Second, by studying changes in interferometric coherence we found that the newly erupted lava lost radar coherence for 5-17 months after the eruption. This suggests changes in the surface backscattering characteristics and was probably related to cooling and compaction processes. Third, the atmospheric delay anomalies in the deformation interferograms were quantitatively assessed. Atmospheric delay anomalies in some of the interferograms were significant and consistently smaller than one to two fringes in magnitude. For this reason, repeat observations are important to confidently interpret small geophysical signals related to volcanic activities. Finally, using two-pass differential interferometry, we analyzed the preemptive inflation, coeruptive deflation, and posteruptive inflation and confirmed the observations using independent image pairs. We observed more than 140 cm of subsidence associated with the 1997 eruption. This subsidence occurred between 16 months before the eruption and 5 months after the eruption, was preceded by ∼18 cm of uplift between 1992 and 1995 centered in the same location, and was followed by ∼10 cm of uplift between September 1997 and 1998. The best fitting model suggests the magma reservoir resided at 2.7 km depth beneath the center of the caldera, which was ∼5 km from the eruptive vent. We estimated the volume of the erupted material to be 0.055 km3 and the average thickness of the erupted lava to be ∼7.4 m. Copyright 2000 by the American Geophysical Union.

  19. Removing interfering clutter associated with radar pulses that an airborne radar receives from a radar transponder

    DOEpatents

    Ormesher, Richard C.; Axline, Robert M.

    2008-12-02

    Interfering clutter in radar pulses received by an airborne radar system from a radar transponder can be suppressed by developing a representation of the incoming echo-voltage time-series that permits the clutter associated with predetermined parts of the time-series to be estimated. These estimates can be used to estimate and suppress the clutter associated with other parts of the time-series.

  20. Space Radar Image of Hampton Roads, Virginia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the Hampton Roads, Virginia region, where the James River (upper left center) flows into the Chesapeake Bay. The city of Norfolk is the bright area on the peninsula in the lower center. Norfolk is home to a large naval base, part of which can be seen as the bright white port facilities near the center of the image. The cities of Hampton and Newport News occupy the peninsula in the upper right of the image. The dark blue areas on this peninsula are the runways of Langley Air Force Base, which also houses NASA's Langley Research Center. Forested areas, including suburbs, appear as green on the image. Cities appear as green, white and orange. The purple areas along the shorelines are wetlands; blue areas are cleared for agricultural use. Faint ship wakes can be seen in the water behind ships entering and leaving Hampton Roads. Scientists are using radar images like this one to study delicate coastal environments and the effects of urbanization and other human activities on the ecosystem and landscape. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on October 5, 1994. The image is centered at 36.9 degrees north latitude, 76.4 degrees west longitude. North is towards the upper right. The area shown is 37 kilometers by 29 kilometers (23 miles by 18 miles). Colors are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received; green is L-band horizontally transmitted, vertically received; blue is C-band horizontally transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's ongoing Mission to Planet Earth program.

  1. Planetary radar studies. [radar mapping of the Moon and radar signatures of lunar and Venus craters

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.; Cutts, J. A.

    1981-01-01

    Progress made in studying the evolution of Venusian craters and the evolution of infrared and radar signatures of lunar crater interiors is reported. Comparison of radar images of craters on Venus and the Moon present evidence for a steady state Venus crater population. Successful observations at the Arecibo Observatory yielded good data on five nights when data for a mix of inner and limb areas were acquired. Lunar craters with radar bright ejects are discussed. An overview of infrared radar crater catalogs in the data base is included.

  2. UWB Impulse Radar Characterization and Processing Techniques

    DTIC Science & Technology

    2004-12-01

    S/B s’améliore de façon à peu près linéaire . L’intégration d’environ 80 impulsions donne lieu à un rapport S/B maximal d’environ 35 dB, avec une...défense Canada (RDDC) a un programme de recherche active sur bien des aspects des systèmes radar à bande ultra-large (UWB), y compris la simulation

  3. Broadview Radar Altimetry Toolbox

    NASA Astrophysics Data System (ADS)

    Mondéjar, Albert; Benveniste, Jérôme; Naeije, Marc; Escolà, Roger; Moyano, Gorka; Roca, Mònica; Terra-Homem, Miguel; Friaças, Ana; Martinho, Fernando; Schrama, Ernst; Ambrózio, Américo; Restano, Marco

    2016-07-01

    The universal altimetry toolbox, BRAT (Broadview Radar Altimetry Toolbox) which can read all previous and current altimetry missions' data, incorporates now the capability to read the upcoming Sentinel-3 L1 and L2 products. ESA endeavoured to develop and supply this capability to support the users of the future Sentinel-3 SAR Altimetry Mission. BRAT is a collection of tools and tutorial documents designed to facilitate the processing of radar altimetry data. This project started in 2005 from the joint efforts of ESA (European Space Agency) and CNES (Centre National d'Études Spatiales), and it is freely available at http://earth.esa.int/brat. The tools enable users to interact with the most common altimetry data formats. The BratGUI is the front-end for the powerful command line tools that are part of the BRAT suite. BRAT can also be used in conjunction with MATLAB/IDL (via reading routines) or in C/C++/Fortran via a programming API, allowing the user to obtain desired data, bypassing the data-formatting hassle. BRAT can be used simply to visualise data quickly, or to translate the data into other formats such as NetCDF, ASCII text files, KML (Google Earth) and raster images (JPEG, PNG, etc.). Several kinds of computations can be done within BRAT involving combinations of data fields that the user can save for posterior reuse or using the already embedded formulas that include the standard oceanographic altimetry formulas. The Radar Altimeter Tutorial, that contains a strong introduction to altimetry, shows its applications in different fields such as Oceanography, Cryosphere, Geodesy, Hydrology among others. Included are also "use cases", with step-by-step examples, on how to use the toolbox in the different contexts. The Sentinel-3 SAR Altimetry Toolbox shall benefit from the current BRAT version. While developing the toolbox we will revamp of the Graphical User Interface and provide, among other enhancements, support for reading the upcoming S3 datasets and

  4. Broadview Radar Altimetry Toolbox

    NASA Astrophysics Data System (ADS)

    Escolà, Roger; Garcia-Mondejar, Albert; Moyano, Gorka; Roca, Mònica; Terra-Homem, Miguel; Friaças, Ana; Martinho, Fernando; Schrama, Ernst; Naeije, Marc; Ambrozio, Americo; Restano, Marco; Benveniste, Jérôme

    2016-04-01

    The universal altimetry toolbox, BRAT (Broadview Radar Altimetry Toolbox) which can read all previous and current altimetry missions' data, incorporates now the capability to read the upcoming Sentinel-3 L1 and L2 products. ESA endeavoured to develop and supply this capability to support the users of the future Sentinel-3 SAR Altimetry Mission. BRAT is a collection of tools and tutorial documents designed to facilitate the processing of radar altimetry data. This project started in 2005 from the joint efforts of ESA (European Space Agency) and CNES (Centre National d'Etudes Spatiales), and it is freely available at http://earth.esa.int/brat. The tools enable users to interact with the most common altimetry data formats. The BratGUI is the front-end for the powerful command line tools that are part of the BRAT suite. BRAT can also be used in conjunction with MATLAB/IDL (via reading routines) or in C/C++/Fortran via a programming API, allowing the user to obtain desired data, bypassing the data-formatting hassle. BRAT can be used simply to visualise data quickly, or to translate the data into other formats such as NetCDF, ASCII text files, KML (Google Earth) and raster images (JPEG, PNG, etc.). Several kinds of computations can be done within BRAT involving combinations of data fields that the user can save for posterior reuse or using the already embedded formulas that include the standard oceanographic altimetry formulas. The Radar Altimeter Tutorial, that contains a strong introduction to altimetry, shows its applications in different fields such as Oceanography, Cryosphere, Geodesy, Hydrology among others. Included are also "use cases", with step-by-step examples, on how to use the toolbox in the different contexts. The Sentinel-3 SAR Altimetry Toolbox shall benefit from the current BRAT version. While developing the toolbox we will revamp of the Graphical User Interface and provide, among other enhancements, support for reading the upcoming S3 datasets and

  5. Space Radar Image of Glascow, Missouri

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false-color L-band image of an area near Glasgow, Missouri, centered at about 39.2 degrees north latitude and 92.8 degrees west longitude. The image was acquired using the L-band radar channel (horizontally transmitted and received and horizontally transmitted/vertically received) polarizations combined. The data were acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on orbit 50 on October 3,1994. The area shown is approximately 37 kilometers by 25 kilometers (23 miles by 16 miles). The radar data, coupled with pre-flood aerial photography and satellite data and post-flood topographic and field data, are being used to evaluate changes associated with levee breaks in landforms, where deposits formed during the widespread flooding in 1993 along the Missouri and Mississippi Rivers. The distinct radar scattering properties of farmland, sand fields and scoured areas will be used to inventory floodplains along the Missouri River and determine the processes by which these areas return to preflood conditions. The image shows one such levee break near Glasgow, Missouri. In the upper center of the radar image, below the bend of the river, is a region covered by several meters of sand, shown as dark regions. West (left) of the dark areas, a gap in the levee tree canopy shows the area where the levee failed. Radar data such as these can help scientists more accurately assess the potential for future flooding in this region and how that might impact surrounding communities. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific

  6. Interferometric radar measurements

    NASA Astrophysics Data System (ADS)

    Smith, Ronald A.; Shipman, Mark; Holder, E. J.; Williams, James K.

    2002-08-01

    The United States Army Space and Missile Defense Command (USASMDC) has interest in a technology demonstration that capitalizes on investment in fire control and smart interceptor technologies that have matured beyond basic research. The concept SWORD (Short range missile defense With Optimized Radar Distribution) consists of a novel approach utilizing a missile interceptor and interferometric fire control radar. A hit-to-kill, closed-loop, command guidance scheme is planned that takes advantage of extremely accurate target and interceptor state vectors derived via the fire control radar. The fire control system has the capability to detect, track, and classify multiple threats in a tactical regime as well as simultaneously provide command guidance updates to multiple missile interceptors. The missile interceptor offers a cost reduction potential as well as an enhancement to the kinematics range and lethality over existing SHORAD systems. Additionally, the Radio Frequency (RF) guidance scheme offers increased battlefield weather performance. The Air Defense (AD) community, responding to current threat capabilities and trends, has identified an urgent need to have a capability to counter proliferated, low cost threats with a low cost-per-kill weapon system. The SWORD system will offer a solution that meets this need. The SWORD critical technologies will be identified including a detailed description of each. Validated test results and basic principles of operation will be presented to prove the merit of past investments. The Deputy Assistant Secretary of the Army for Research and Technology (DAS(R&T) has a three- year Science and Technology Program to evaluate the errors and proposed mitigation techniques associated with target spectral dispersion and range gate straddle. Preliminary bench-top experiment results will be presented in this paper.

  7. Venus - First Radar Test

    NASA Technical Reports Server (NTRS)

    1990-01-01

    After traveling more than 1.5 billion kilometers (948 million miles), the Magellan spacecraft was inserted into orbit around Venus on Aug. 10, 1990. This mosaic consists of adjacent pieces of two Magellan image strips obtained on Aug. 16 in the first radar test. The radar test was part of a planned In Orbit Checkout sequence designed to prepare the Magellan spacecraft and radar to begin mapping after Aug. 31. The strip on the left was returned to the Goldstone Deep Space Network station in California; the strip to the right was received at the DSN in Canberra, Australia. A third station that will be receiving Magellan data is located near Madrid, Spain. Each image strip is 20 km (12 miles) wide and 16,000 km (10,000 miles) long. This mosaic is a small portion 80 km (50 miles) long. This image is centered at 21 degrees north latitude and 286.8 degrees east longitude, southeast of a volcanic highland region called Beta Regio. The resolution of the image is about 120 meters (400 feet), 10 times better than previous images of the same area of Venus, revealing many new geologic features. The bright line trending northwest southeast across the center of the image is a fracture or fault zone cutting the volcanic plains. In the upper left corner of the image, a multiple ring circular feature of probable volcanic origin can be seen, approximately 4.27 km (2.65 miles) across. The bright and dark variations seen in the plains surrounding these features correspond to volcanic lava flows of varying ages. The volcanic lava flows in the southern half of the image have been cut by north south trending faults. This area is similar geologically to volcanic deposits seen on Earth at Hawaii and the Snake River Plains in Idaho.

  8. Doppler radar flowmeter

    DOEpatents

    Petlevich, Walter J.; Sverdrup, Edward F.

    1978-01-01

    A Doppler radar flowmeter comprises a transceiver which produces an audio frequency output related to the Doppler shift in frequency between radio waves backscattered from particulate matter carried in a fluid and the radiated radio waves. A variable gain amplifier and low pass filter are provided for amplifying and filtering the transceiver output. A frequency counter having a variable triggering level is also provided to determine the magnitude of the Doppler shift. A calibration method is disclosed wherein the amplifier gain and frequency counter trigger level are adjusted to achieve plateaus in the output of the frequency counter and thereby allow calibration without the necessity of being able to visually observe the flow.

  9. Weather Radar Studies

    DTIC Science & Technology

    1988-03-31

    Reflectivity Core Recognition 68 IV-10 Middle-Level Precursor Recognition 69 IV-l I Early Microburst Hazard Declaration 70 IV-12 Example of Results from...Denver Test Bed 106 V-I Selected Product Types 14 V-2 Encoded Map Size (in ELMs ) for Terminal Map Data Set 119 V-3 Encoded Map Size (in ELMs ) for En...Route Data Sets 119 V-4 Encoded Map Size (in ELMs ) for Terminal Map Data Set 125 xiii WEATHER RADAR STUDIES 1. INTRODUCTION The principal areas of

  10. Radar Exploration of Cometary Nuclei

    NASA Astrophysics Data System (ADS)

    Gim, Yonggyu; Heggy, E.; Belton, M.; Weissman, P.; Asphaug, E.

    2012-10-01

    We have developed a mission formulation, based on the use of previously flown planetary radar sounding techniques, to image the 3D internal structure of the nucleus of a Jupiter-family comet (JFC). Believed to originate in the outer solar system and to be delivered recently to the inner solar system from the Kuiper Belt, JFCs are among the most primitive bodies accessible by spacecraft, and are indicated in the 2010 Decadal Survey as primary targets for primitive bodies sample return. We consider a sounder design operating at dual frequencies, 5 and 15 MHz center frequencies with 1 and 10 MHz bandwidths, respectively. Operating from close orbit about the nucleus of a spinning comet nucleus, CORE obtains a dense network of echoes that are used to image its interior structure to 10 m and to map the dielectric properties inside the nucleus to better than 200 m throughout. Clear images of internal structure and dielectric composition will reveal how the nucleus was formed and how it has evolved. Radiometric tracking of the spacecraft orbit will provide an interior mass distribution that constrains the radar-based models of interior composition. High-resolution visible and infrared color images provide surface and exterior boundary conditions for interior models and hypotheses. They present the geology and morphology of the nucleus surface at meter-scales, and the time-evolving activity, structure, and composition of the inner coma. By making global yet detailed connections from interior to exterior, the data from CORE will provide answers to fundamental questions about the earliest stages of planetesimal evolution and planet formation, will be an important complement to the Rosetta mission science, and will lay the foundation for comet nucleus sample return.

  11. Use of radar image texture in geologic mapping

    NASA Technical Reports Server (NTRS)

    Farr, T. G.

    1983-01-01

    Large slope angle radar and small slope angle radar techniques are discussed. The techniques are developed to aid in the geologic interpretation of synthetic aperture radar (SAR) images. The application presented is for heavy vegetation and where very little other data can be obtained directly from remote sensing images. To understand the relationships between image texture, topography, lithology, geomorphology, and climate improves, textural information from SAR images are used for the identification of rock types to discriminate units. An active program is to integrate textural information from radar images directly with backscatter data from the same images, and with compositional information derived from visible near infrared sensors such as LANDSAT is explored. The role of quantitative textural information in this type of multisensor analysis which promises to be significant is outlined.

  12. Radar Imaging and Feature Extraction

    DTIC Science & Technology

    2007-11-02

    aperture radar (ISAR) autofocus and imaging, synthetic aperture radar (SAR) autofocus and motion compensation, superresolution SAR image formation... superresolution image formation, and two parametric methods, MCRELAX (Motion Compensation RELAX) and MCCLEAN (Motion Compensation CLEAN), for simultaneous target...Direction Estimation) together with WRELAX) algorithm is proposed for the superresolution time delay estimation.

  13. Millimeter radar improves target identification

    NASA Astrophysics Data System (ADS)

    McAulay, Alastair D.

    2011-06-01

    Recently developed millimeter wave radar has advantages for target identification over conventional microwave radar which typically use lower frequencies. We describe the pertinent features involved in the construction of the new millimeter wave radar, the pseudo-optical cavity source and the quasi-optical duplexer. The long wavelength relative to light allows the radar beam to penetrate through most weather because the wavelength is larger than the particle size for dust, drizzle rain, fog. Further the mm wave beam passes through an atmospheric transmission window that provides a dip in attenuation. The higher frequency than conventional radar provides higher Doppler frequencies, for example, than X-band radar. We show by simulation that small characteristic vibrations and slow turns of an aircraft become visible so that the Doppler signature improves identification. The higher frequency also reduces beam width, which increases transmit and receive antenna gains. For the same power the transmit beam extends to farther range and the increase in receive antenna gain increases signal to noise ratio for improved detection and identification. The narrower beam can also reduce clutter and reject other noise more readily. We show by simulation that the radar can be used at lower elevations over the sea than conventional radar.

  14. Radar Control Optimal Resource Allocation

    DTIC Science & Technology

    2015-07-13

    Dartmouth, Nova Scotia, Canada by the McMaster University Intelligent PIXel (IPIX) X-band Polarimetric Coherent Radar during the OHGR - Dartmouth...Distribution is unlimited Wind Direction N Figure 7: Radar data collection site at OHGR, Nova Scotia. Source:[15] to having a significant wave height of 0.7 m

  15. High-resolution instrumentation radar

    NASA Astrophysics Data System (ADS)

    Dybdal, Robert B.; Hurlbut, Keith H.; Mori, Tsutomu T.

    1986-09-01

    The development of an instrumentation radar that uses a chirp waveform to achieve high range resolution is described. Such range resolution capability is required for two reasons: (1) to evaluate the response of targets to the operational waveforms used in high-performance radars; and (2) to obtain a means of separating the individual mechanisms that comprise the target scattering response to better understand the scattering process. This particular radar was efficiently constructed from a combination of commercially available components and in-house-fabricated circuitry. This instrumentation radar operates at X-band and achieves a 4.9-in. range resolution. A key feature of the radar is its ability to combine amplitude weighting with a high degree of waveform fidelity, with the result being very good range sidelobe performance.

  16. A radar image time series

    NASA Technical Reports Server (NTRS)

    Leberl, F.; Fuchs, H.; Ford, J. P.

    1981-01-01

    A set of ten side-looking radar images of a mining area in Arizona that were aquired over a period of 14 yr are studied to demonstrate the photogrammetric differential-rectification technique applied to radar images and to examine changes that occurred in the area over time. Five of the images are rectified by using ground control points and a digital height model taken from a map. Residual coordinate errors in ground control are reduced from several hundred meters in all cases to + or - 19 to 70 m. The contents of the radar images are compared with a Landsat image and with aerial photographs. Effects of radar system parameters on radar images are briefly reviewed.

  17. Shuttle Imaging Radar - Geologic applications

    NASA Technical Reports Server (NTRS)

    Macdonald, H.; Bridges, L.; Waite, W.; Kaupp, V.

    1982-01-01

    The Space Shuttle, on its second flight (November 12, 1981), carried the first science and applications payload which provided an early demonstration of Shuttle's research capabilities. One of the experiments, the Shuttle Imaging Radar-A (SIR-A), had as a prime objective to evaluate the capability of spaceborne imaging radars as a tool for geologic exploration. The results of the experiment will help determine the value of using the combination of space radar and Landsat imagery for improved geologic analysis and mapping. Preliminary analysis of the Shuttle radar imagery with Seasat and Landsat imagery from similar areas provides evidence that spaceborne radars can significantly complement Landsat interpretation, and vastly improve geologic reconnaissance mapping in those areas of the world that are relatively unmapped because of perpetual cloud cover.

  18. Low-brightness quantum radar

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco

    2015-05-01

    One of the major scientific thrusts from recent years has been to try to harness quantum phenomena to dramatically increase the performance of a wide variety of classical information processing devices. These advances in quantum information science have had a considerable impact on the development of standoff sensors such as quantum radar. In this paper we analyze the theoretical performance of low-brightness quantum radar that uses entangled photon states. We use the detection error probability as a measure of sensing performance and the interception error probability as a measure of stealthiness. We compare the performance of quantum radar against a coherent light sensor (such as lidar) and classical radar. In particular, we restrict our analysis to the performance of low-brightness standoff sensors operating in a noisy environment. We show that, compared to the two classical standoff sensing devices, quantum radar is stealthier, more resilient to jamming, and more accurate for the detection of low reflectivity targets.

  19. Radar SLAM using visual features

    NASA Astrophysics Data System (ADS)

    Callmer, Jonas; Törnqvist, David; Gustafsson, Fredrik; Svensson, Henrik; Carlbom, Pelle

    2011-12-01

    A vessel navigating in a critical environment such as an archipelago requires very accurate movement estimates. Intentional or unintentional jamming makes GPS unreliable as the only source of information and an additional independent supporting navigation system should be used. In this paper, we suggest estimating the vessel movements using a sequence of radar images from the preexisting body-fixed radar. Island landmarks in the radar scans are tracked between multiple scans using visual features. This provides information not only about the position of the vessel but also of its course and velocity. We present here a navigation framework that requires no additional hardware than the already existing naval radar sensor. Experiments show that visual radar features can be used to accurately estimate the vessel trajectory over an extensive data set.

  20. Space Radar Image of Kilauea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a deformation map of the south flank of Kilauea volcano on the big island of Hawaii, centered at 19.5 degrees north latitude and 155.25 degrees west longitude. The map was created by combining interferometric radar data -- that is data acquired on different passes of the space shuttle which are then overlayed to obtain elevation information -- acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar during its first flight in April 1994 and its second flight in October 1994. The area shown is approximately 40 kilometers by 80 kilometers (25 miles by 50 miles). North is toward the upper left of the image. The colors indicate the displacement of the surface in the direction that the radar instrument was pointed (toward the right of the image) in the six months between images. The analysis of ground movement is preliminary, but appears consistent with the motions detected by the Global Positioning System ground receivers that have been used over the past five years. The south flank of the Kilauea volcano is among the most rapidly deforming terrains on Earth. Several regions show motions over the six-month time period. Most obvious is at the base of Hilina Pali, where 10 centimeters (4 inches) or more of crustal deformation can be seen in a concentrated area near the coastline. On a more localized scale, the currently active Pu'u O'o summit also shows about 10 centimeters (4 inches) of change near the vent area. Finally, there are indications of additional movement along the upper southwest rift zone, just below the Kilauea caldera in the image. Deformation of the south flank is believed to be the result of movements along faults deep beneath the surface of the volcano, as well as injections of magma, or molten rock, into the volcano's 'plumbing' system. Detection of ground motions from space has proven to be a unique capability of imaging radar technology. Scientists hope to use deformation data acquired by SIR-C/X-SAR and future imaging

  1. Mars Radar Observations with the Goldstone Solar System Radar

    NASA Technical Reports Server (NTRS)

    Haldemann, A. F. C.; Jurgens, R. F.; Larsen, K. W.; Arvidson, R. E.; Slade, M. A.

    2002-01-01

    The Goldstone Solar System Radar (GSSR) has successfully collected radar echo data from Mars over the past 30 years. As such, the GSSR has played a role as a specific mission element within Mars exploration. The older data provided local elevation information for Mars, along with radar scattering information with global resolution. Since the upgrade to the 70-m Deep Space Network (DSN) antenna at Goldstone completed in 1986, Mars data has been collected during all but the 1997 Mars opposition. Radar data, and non-imaging delay-Doppler data in particular, requires significant data processing to extract elevation, reflectivity and roughness of the reflecting surface. The spatial resolution of these experiments is typically some 20 km in longitude by some 150 km in latitude. The interpretation of these parameters while limited by the complexities of electromagnetic scattering, do provide information directly relevant to geophysical and geomorphic analyses of Mars. The usefulness of radar data for Mars exploration has been demonstrated in the past. Radar data were critical in assessing the Viking Lander 1 site as well as, more recently, the Pathfinder landing site. In general, radar data have not been available to the Mars exploration community at large. A project funded initially by the Mars Exploration Directorate Science Office at the Jet Propulsion Laboratory (JPL), and later funded by NASA's Mars Data Analysis Program has reprocessed to a common format a decade's worth of raw GSSR Mars delay-Doppler data in aid of landing site characterization for the Mars Program. These data will soon be submitted to the Planetary Data System (PDS). The radar data used were obtained between 1988 and 1995 by the GSSR, and comprise some 63 delay-Doppler radar tracks. Of these, 15 have yet to be recovered from old 9-track tapes, and some of the data may be permanently lost.

  2. Autonomous system for initializing synthetic aperture radar seeker acquisition

    SciTech Connect

    Hamilton, P.C.

    1993-08-03

    A method is described of guiding a missile having an active seeker including a synthetic aperture radar operating in a squint mode to a target aircraft having a search radar therein the maximum range of active seeker acquisition being within said missile's maneuver capability to intercept, and the maximum range of active seeker acquisition not exceeding the capability of the active seeker, said method comprising the steps of: launching said missile in response to detection of the search radar; implementing a passive seeker mode of operation to passively guide said missile towards said target aircraft in a manner to avoid detection of said missile by said target aircraft; transferring from said passive seeker mode to an active seeker mode in response to detected shutdown of said search radar; maneuvering said missile to execute a turn angle away from said target aircraft such that the search field of said synthetic aperture radar sweeps through an entire target uncertainty volume, said turn angle being within a first preselected limit and a second preselected limit such that said target aircraft does not cross over said missile's terminal flight path; and intercepting said target aircraft within a lethal range of said missile.

  3. The HYDROS Radiometer/Radar Instrument

    NASA Technical Reports Server (NTRS)

    Spencer, Michael W.; Njoku, Eni; Entekhabi, Dara; Doiron, Terence; Piepmeier, Jeffrey; Girard, Ralph

    2004-01-01

    The science objectives of the HYDROS mission are to provide frequent, global measurements of surface soil moisture and surface freeze/thaw state. In order to adequately measure these geophysical quantities, the key instrument requirements were determined by the HYDROS science team to be: 1) Dual-polarization L-Band passive radiometer measurements at 40 km resolution, 2) Dual-polarization L-Band active radar measurements at 3 km resolution, and 3) A wide swath to insure global three day refresh time for these measurements (1000 km swath at the selected orbit altitude of 670 km). As a solution to this challenging set of instrument requirements, a relatively large, 6 meter, conically-scanning reflector antenna architecture was selected for the instrument design. The deployable mesh antenna is shared by both the radiometer and radar electronics by employing a single L-Band feed.

  4. Rendezvous radar for the orbital maneuvering vehicle

    NASA Technical Reports Server (NTRS)

    Locke, John W.; Olds, Keith A.; Quaid, Thomas

    1991-01-01

    The Rendezvous Radar Set (RRS) was designed at Motorola's Strategic Electronics Division in Chandler, Arizona, to be a key subsystem aboard NASA's Orbital Maneuvering Vehicle (OMV). The unmanned OMV, which was under development at TRW's Federal Systems Division in Redondo Beach, California, was designed to supplement the Shuttle's satellite delivery, retrieval, and maneuvering activities. The RRS was to be used to locate and then provide the OMV with vectoring information to the target satellite (or Shuttle or Space Station) to aid the OMV in making a minimum fuel consumption approach and rendezvous. The OMV development program was halted by NASA in 1990 just as parts were being ordered for the RRS engineering model. The paper presented describes the RRS design and then discusses new technologies, either under development or planned for development at Motorola, that can be applied to radar or alternative sensor solutions for the Automated Rendezvous and Capture problem.

  5. Methods And System Suppressing Clutter In A Gain-Block, Radar-Responsive Tag System

    DOEpatents

    Ormesher, Richard C.; Axline, Robert M.

    2006-04-18

    Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing reverses the direction, in time, of the received waveform's linear frequency modulation. The tag retransmits the remodulated pulses. The radar uses a reversed-chirp de-ramp pulse to process the tag's echo. The invention applies to radar systems compatible with coherent gain-block tags. The invention provides a marked reduction in the strength of residual clutter echoes on each and every echo pulse received by the radar. SAR receiver processing effectively whitens passive-clutter signatures across the range dimension. Clutter suppression of approximately 14 dB is achievable for a typical radar system.

  6. Ground Penetrating Radar Technologies in Ukraine

    NASA Astrophysics Data System (ADS)

    Pochanin, Gennadiy P.; Masalov, Sergey A.

    2014-05-01

    projects on the delineation of a diamond deposit in Karelia, on the localisation of unauthorized penetrations in product pipelines, and others. Since 2007, in close cooperation with researchers from V. N. Karazin Kharkiv National University (www.univer.kharkov.ua/en) and Kharkiv National Automobile and Highway University (www.khadi.kharkov.ua), we have been developing a GPR to monitor road conditions. The main objective is the creation of an equipment suitable to determine the strength characteristics of pavements. A GPR allowing to measure thicknesses of asphalt pavement layers with an accuracy better than 3 mm has already been created; it was transferred to services responsible for maintaining roads in good condition. Specific standards and guidelines for the use of GPR has not been adopted in Ukraine, yet. GPRs are rarely used by public services. Nevertheless, recently the Ukrainian government has funded several projects on GPR technologies. Ukrainians seek to maintain old and to establish new relationships with colleagues around the world. We were partners of the Ultrawideband Radar Working Group, which developed the standard "IEEE P1672 TM Ultrawideband Radar Definitions." LLC "Transient Technologies" has cooperation agreements with more than a dozen of GPR companies all over the world. A group of scientists from IRE is working in cooperation with researchers from Italy, Holland, Turkey, Brazil, Russia and Ukraine on the project of FP-7-PEOPLE-2010-IRSES no 269157 "Active and Passive Microwaves for Security and Subsurface Imaging" (for more details, please visit www.irea.cnr.it/en/index.php?option=com_k2&view=item&id=342:progetto-amiss&Itemid=165). In recent years, many representative companies have appeared, offering GPRs of foreign production on the market of Ukraine. The authors acknowledge COST for funding Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar," supporting this work.

  7. 47 CFR 80.273 - Radar standards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7):...

  8. 47 CFR 80.273 - Radar standards.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7):...

  9. FIRE_CI2_ETL_RADAR

    Atmospheric Science Data Center

    2015-11-25

    FIRE_CI2_ETL_RADAR Project Title:  FIRE II CIRRUS Discipline:  ... Platform:  Ground Station Instrument:  Radar Spatial Coverage:  (37.06, -95.34) Spatial ... Search Guide Documents:  ETL_RADAR Guide Readme Files:  Readme ETL_RADAR (PS) ...

  10. 47 CFR 80.273 - Radar standards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7):...

  11. RADAR OBSERVATION CONDITIONS OF POOR VISIBILITY,

    DTIC Science & Technology

    Ship navigational radar is an effective means for revealing above-water objects in conditions of poor visibility. A radar image of the surrounding...radar observation and with the competent operation of the set, radar is a reliable means of detection of encountered vessels in conditions of poor

  12. Radar, Insect Population Ecology, and Pest Management

    NASA Technical Reports Server (NTRS)

    Vaughn, C. R. (Editor); Wolf, W. (Editor); Klassen, W. (Editor)

    1979-01-01

    Discussions included: (1) the potential role of radar in insect ecology studies and pest management; (2) the potential role of radar in correlating atmospheric phenomena with insect movement; (3) the present and future radar systems; (4) program objectives required to adapt radar to insect ecology studies and pest management; and (5) the specific action items to achieve the objectives.

  13. Evaluation of meteorological airborne Doppler radar

    NASA Technical Reports Server (NTRS)

    Hildebrand, P. H.; Mueller, C. K.

    1984-01-01

    This paper will discuss the capabilities of airborne Doppler radar for atmospheric sciences research. The evaluation is based on airborne and ground based Doppler radar observations of convective storms. The capability of airborne Doppler radar to measure horizontal and vertical air motions is evaluated. Airborne Doppler radar is shown to be a viable tool for atmospheric sciences research.

  14. Large phased-array radars

    SciTech Connect

    Brookner, D.E.

    1988-12-15

    Large phased-array radars can play a very important part in arms control. They can be used to determine the number of RVs being deployed, the type of targeting of the RVs (the same or different targets), the shape of the deployed objects, and possibly the weight and yields of the deployed RVs. They can provide this information at night as well as during the day and during rain and cloud covered conditions. The radar can be on the ground, on a ship, in an airplane, or space-borne. Airborne and space-borne radars can provide high resolution map images of the ground for reconnaissance, of anti-ballistic missile (ABM) ground radar installations, missile launch sites, and tactical targets such as trucks and tanks. The large ground based radars can have microwave carrier frequencies or be at HF (high frequency). For a ground-based HF radar the signal is reflected off the ionosphere so as to provide over-the-horizon (OTH) viewing of targets. OTH radars can potentially be used to monitor stealth targets and missile traffic.

  15. Space radar image of Mauna Loa, Hawaii

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This image of the Mauna Loa volcano on the Big Island of Hawaii shows the capability of imaging radar to map lava flows and other volcanic structures. Mauna Loa has erupted more than 35 times since the island was first visited by westerners in the early 1800s. The large summit crater, called Mokuaweoweo Caldera, is clearly visible near the center of the image. Leading away from the caldera (towards top right and lower center) are the two main rift zones shown here in orange. Rift zones are areas of weakness within the upper part of the volcano that are often ripped open as new magma (molten rock) approaches the surface at the start of an eruption. The most recent eruption of Mauna Loa was in March and April 1984, when segments of the northeast rift zones were active. If the height of the volcano was measured from its base on the ocean floor instead of from sea level, Mauna Loa would be the tallest mountain on Earth. Its peak (center of the image) rises more than 8 kilometers (5 miles) above the ocean floor. The South Kona District, known for cultivation of macadamia nuts and coffee, can be seen in the lower left as white and blue areas along the coast. North is toward the upper left. The area shown is 41.5 by 75 kilometers (25.7 by 46.5 miles), centered at 19.5 degrees north latitude and 155.6 degrees west longitude. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/ X-SAR) aboard the space shuttle Endeavour on its 36th orbit on October 2, 1994. The radar illumination is from the left of the image. The colors in this image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted, vertically received); blue represents the C-band (horizontally transmitted, vertically received). The resulting color combinations in this radar image are caused by differences in surface roughness of the lava flows. Smoother flows

  16. SPace Radar Image of Fort Irwin, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This image of Fort Irwin in California's Mojave Desert compares interferometric radar signatures topography -- data that were obtained by multiple imaging of the same region to produce three-dimensional elevation maps -- as it was obtained on October 7-8, 1994 by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar aboard the space shuttle Endeavour. Data were acquired using the L-band (24 centimeter wavelength) and C-band (6 centimeter wavelength). The image covers an area about 25 kilometers by 70 kilometers (15.5 miles by 43 miles). North is to the lower right of the image. The color contours shown are proportional to the topographic elevation. With a wavelength one-fourth that of the L-band, the results from the C-band cycle through the color contours four times faster for a given elevation change. Detailed comparisons of these multiple frequency data over different terrain types will provide insights in the future into wavelength-dependent effects of penetration and scattering on the topography measurement accuracy. Fort Irwin is an ideal site for such detailed digital elevation model comparisons because a number of high precision digital models of the area already exist from conventional measurements as well as from airborne interferometric SAR data. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human

  17. Space Radar Image of Raco Vegetation Map

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a vegetation map of the Raco, Michigan area produced from data acquired by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard space shuttle Endeavour. The radar image, taken on April 9, 1994, has been used by science team members at the University of Michigan to produce detailed map of land cover. This image is centered at 46.4 degrees north latitude and 84.9 degrees west longitude. The imaged area is approximately 24 by 32 kilometers (15 by 20 miles). The Raco airport, which is a decommissioned military base, is easily identified by its triangular runway structure. An edge of Lake Superior, approximately 44 kilometers (27 miles) west of Sault Sainte Marie, appears in the top right of the image. In this land cover map each 30- by 30-meter (98- by 98-foot) spot is identified as either a water surface, bare ground, short vegetation, deciduous forest, lowland conifers or upland conifers. Different types of ground cover have different effects on Earth's chemical, water and energy cycles. By cataloguing ground cover in an area, scientists expect to better understand the processes of these cycles in a specific area. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio

  18. Space Radar Image of Cape Cod, Massachusetts

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image shows the famous 'hook' of Cape Cod, Massachusetts. The Cape, which juts out into the Atlantic Ocean about 100 kilometers (62 miles) southeast of Boston, actually consists of sandy debris left behind by the great continental ice sheets when they last retreated from southern New England about 20,000 years ago. Today's landscape consists of sandy forests, fields of scrub oak and other bushes and grasses, salt marshes, freshwater ponds, as well as the famous beaches and sand dunes. In this image, thickly forested areas appear green, marshes are dark blue, ponds and sandy areas are black, and developed areas are mostly pink. The dark L-shape in the lower center is the airport runways in Hyannis, the Cape's largest town. The dark X-shape left of the center is Otis Air Force Base. The Cape Cod Canal, above and left of center, connects Buzzards Bay on the left with Cape Cod Bay on the right. The northern tip of the island of Martha's Vineyard is seen in the lower left. The tip of the Cape, in the upper right, includes the community of Provincetown, which appears pink, and the protected National Seashore areas of sand dunes that parallel the Atlantic coast east of Provincetown. Scientists are using radar images like this one to study delicate coastal environments and the effects of human activities on the ecosystem and landscape. This image was acquired by Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on April 15, 1994. The image is 81.7 kilometers by 43.1 kilometers (50.7 miles by 26.7 miles) and is centered at 41.8 degrees north latitude, 70.3 degrees west longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted, vertically received; and blue is C-band, horizontally transmitted and received. SIR

  19. Study on the shipboard radar reconnaissance equipment azimuth benchmark method

    NASA Astrophysics Data System (ADS)

    Liu, Zhenxing; Jiang, Ning; Ma, Qian; Liu, Songtao; Wang, Longtao

    2015-10-01

    The future naval battle will take place in a complex electromagnetic environment. Therefore, seizing the electromagnetic superiority has become the major actions of the navy. Radar reconnaissance equipment is an important part of the system to obtain and master battlefield electromagnetic radiation source information. Azimuth measurement function is one of the main function radar reconnaissance equipments. Whether the accuracy of direction finding meets the requirements, determines the vessels successful or not active jamming, passive jamming, guided missile attack and other combat missions, having a direct bearing on the vessels combat capabilities . How to test the performance of radar reconnaissance equipment, while affecting the task as little as possible is a problem. This paper, based on radar signal simulator and GPS positioning equipment, researches and experiments on one new method, which povides the azimuth benchmark required by the direction-finding precision test anytime anywhere, for the ships at jetty to test radar reconnaissance equipment performance in direction-finding. It provides a powerful means for the naval radar reconnaissance equipments daily maintenance and repair work[1].

  20. Radar Backscatter Saturation with Forest Biomass: Facts and Myths

    NASA Astrophysics Data System (ADS)

    Saatchi, S. S.

    2012-12-01

    In recent years, climate change policies and scientific research created a widespread interest in quantify the carbon stock and changes of global forests extending from forest patches to national and regional scales. However, because of the large spatial extent of forests, their heterogeneity from structural and species diversity causing meters to kilometer scales variations, their complex dynamics causing landscape scale differences in changes of biomass, and their continues degradation from human activities, the quantification of forest biomass from conventional inventory data alone has become a major challenge. Remote sensing techniques with Lidar and Radar are considered to be the most efficient way of estimating forest biomass at large scales and with uncertainty comparable to estimation from inventory plots. Radar backscatter and interferometric based estimation of forest biomass has been studied extensively and considered as dedicated spaceborne options of monitoring and quantifying forest biomass. However, the literature on the radar-based estimation techniques of biomass has been misleading in defining the sensitivity and lack of sensitivity, so called saturation effect of radar measurements. In this paper, I provide results from a combination of observations and model simulations to demonstrate the physical nature of the loss of sensitivity of radar backscatter to biomass, examine the biophysical that impact the sensitivity, extend the results to other radar measurements including polarimetric and interferometric modes.

  1. Output tube emission characteristics of operational radars

    NASA Astrophysics Data System (ADS)

    Matheson, R. J.; Smilley, J. D.; Falcon, G. D.; Lawrence, V. S.

    1982-01-01

    Measurement of the emission spectra and other characteristics of many radars operating in the government frequency bands is described. The emission spectra of 19 different types of radars, selected to show the different emission spectrum characteristics produced by a variety of radar output tube technologies are presented. The radars include examples of ground based search, airport surveillance, weather, and height finding radars operating in L band, S band, or C band. The RSMS, contained within a mobile van, is described, along with the measurement techniques used for obtaining radar emission characteristics. The emission limits imposed by the Radar Spectrum Engineering Criteria (RSEC) are displayed with each emission spectrum.

  2. Principles and applications of imaging radar. Manual of remote sensing: Third edition, Volume 2

    SciTech Connect

    Henderson, F.M.; Lewis, A.J.

    1998-12-31

    This second volume in the Third Edition of the Manual of Remote Sensing offers a current and comprehensive survey of the theory, methods, and applications of imaging radar for geoscientists, engineers and application scientists interested in the advantages of radar remote sensing. Produced under the auspices of the American Society for Photogrammetry and Remote Sensing, it brings together contributions from experts around the world to discuss the basic principles of imaging radars and trace the research activity--past, present, and future--across the many sciences where radar remote sensing may be applied. This book offers an invaluable snapshot of radar remote sensing technology, including radargrammetry, radar polarimetry and interferometry and its uses. It combines technical and procedural coverage of systems, data interpretation, and other fundamentals with generous coverage of practical applications in agriculture; forestry; soil moisture monitoring; geology; geomorphology and hydrology; oceanography; land use, land cover mapping and archeology.

  3. Rapid and stable measurement of respiratory rate from Doppler radar signals using time domain autocorrelation model.

    PubMed

    Sun, Guanghao; Matsui, Takemi

    2015-01-01

    Noncontact measurement of respiratory rate using Doppler radar will play a vital role in future clinical practice. Doppler radar remotely monitors the tiny chest wall movements induced by respiration activity. The most competitive advantage of this technique is to allow users fully unconstrained with no biological electrode attachments. However, the Doppler radar, unlike other contact-type sensors, is easily affected by the random body movements. In this paper, we proposed a time domain autocorrelation model to process the radar signals for rapid and stable estimation of the respiratory rate. We tested the autocorrelation model on 8 subjects in laboratory, and compared the respiratory rates detected by noncontact radar with reference contact-type respiratory effort belt. Autocorrelation model showed the effects of reducing the random body movement noise added to Doppler radar's respiration signals. Moreover, the respiratory rate can be rapidly calculated from the first main peak in the autocorrelation waveform within 10 s.

  4. Antarctic meteor observations using the Davis MST and meteor radars

    NASA Astrophysics Data System (ADS)

    Holdsworth, David A.; Murphy, Damian J.; Reid, Iain M.; Morris, Ray J.

    2008-07-01

    This paper presents the meteor observations obtained using two radars installed at Davis (68.6°S, 78.0°E), Antarctica. The Davis MST radar was installed primarily for observation of polar mesosphere summer echoes, with additional transmit and receive antennas installed to allow all-sky interferometric meteor radar observations. The Davis meteor radar performs dedicated all-sky interferometric meteor radar observations. The annual count rate variation for both radars peaks in mid-summer and minimizes in early Spring. The height distribution shows significant annual variation, with minimum (maximum) peak heights and maximum (minimum) height widths in early Spring (mid-summer). Although the meteor radar count rate and height distribution variations are consistent with a similar frequency meteor radar operating at Andenes (69.3°N), the peak heights show a much larger variation than at Andenes, while the count rate maximum-to-minimum ratios show a much smaller variation. Investigation of the effects of the temporal sampling parameters suggests that these differences are consistent with the different temporal sampling strategies used by the Davis and Andenes meteor radars. The new radiant mapping procedure of [Jones, J., Jones, W., Meteor radiant activity mapping using single-station radar observations, Mon. Not. R. Astron. Soc., 367(3), 1050-1056, doi: 10.1111/j.1365-2966.2006.10025.x, 2006] is investigated. The technique is used to detect the Southern delta-Aquarid meteor shower, and a previously unknown weak shower. Meteoroid speeds obtained using the Fresnel transform are presented. The diurnal, annual, and height variation of meteoroid speeds are presented, with the results found to be consistent with those obtained using specular meteor radars. Meteoroid speed estimates for echoes identified as Southern delta-Aquarid and Sextantid meteor candidates show good agreement with the theoretical pre-atmospheric speeds of these showers (41 km s -1 and 32 km s -1

  5. The Clementine bistatic radar experiment.

    PubMed

    Nozette, S; Lichtenberg, C L; Spudis, P; Bonner, R; Ort, W; Malaret, E; Robinson, M; Shoemaker, E M

    1996-11-29

    During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, beta, for selected lunar areas. Observations of the lunar south pole yield a same-sense polarization enhancement around beta = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole.

  6. Gyroklystron-Powered WARLOC Radar

    NASA Astrophysics Data System (ADS)

    Danly, B. G.; Cheung, W. J.; Gregers-Hansen, V.; Linde, G.; Ngo, M.

    2003-12-01

    A high-power, coherent, W-band (94 GHz) millimeter-wave radar has been developed at the Naval Research Laboratory. This radar, named WARLOC, employs a 100 kW peak power, 10 kW average power gyro-klystron as the final power amplifier, an overmoded transmission line system, and a quasi-optical duplexer, together with a high gain antenna, four-channel receiver, and state-of-the-art signal processing. The gyro-amplifiers and the implementation in the WARLOC radar will be described.

  7. The Clementine Bistatic Radar Experiment

    NASA Technical Reports Server (NTRS)

    Nozette, S.; Lichtenberg, C. L.; Spudis, P.; Bonner, R.; Ort, W.; Malaret, E.; Robinson, M.; Shoemaker, E. M.

    1996-01-01

    During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, beta, for selected lunar areas. Observations of the lunar south pole yield a same-sense polarization enhancement around beta = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole.

  8. The Clementine bistatic radar experiment

    USGS Publications Warehouse

    Nozette, S.; Lichtenberg, C.L.; Spudis, P.; Bonner, R.; Ort, W.; Malaret, E.; Robinson, M.; Shoemaker, E.M.

    1996-01-01

    During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, ??, for selected lunar areas. Observations of the lunar south pole yield a same- sense polarization enhancement around ?? = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole.

  9. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1982-01-01

    The dual polarization CW radar system which permits simultaneous reception in the same rotational sense of circular polarization as transmitted (i.e., the "SC" sense) and in the opposite ("OC") sense, was used to observe five previously unobserved asteroids: 2 Pallas, 8 Flora, 22 Kalliope, 132 Aethra, and 471 Papagena. Echoes from Pallas and Flora were easily detected in the OC sense on each of several nights. Weighted mean echo power spectra also show marginally significant responses in the SC sense. An approximately 4.5 standard deviation signal was obtained for Aethra. The Doppler shift of the peak is about 10 Hz higher than that predicted from the a priori trial ephemeris. Calculations are performed to determine whether this frequency offset can be reconciled dynamically with optical positions reported for Aethra.

  10. Radar investigation of asteroids

    NASA Astrophysics Data System (ADS)

    Ostro, S. J.

    1981-07-01

    Radar investigations were conducted of selected minor planets, including: (1) observations during 1981-82 of 10 potential targets (2 Pallas, 8 Flora, 12 Victoria, 15 Eunomia, 19 Fortuna, 22 Kalliope, 132 Aethra, 219 Thusnelda, 433 Eros, and 2100 Ra-Shalom); and (2) continued analyses of observational data obtained during 1980-81 for 10 other asteroids (4 Vesta, 7 Iris, 16 Psyche, 75 Eurydike, 97 Klotho, 216 Kleopatra, 1685 Toro, 1862 Apollo, 1865 Cerberus, and 1915 Quetzalcoatl). Scientific objectives include estimation of echo strength, polarization, spectral shape, spectral bandwidth, and Doppler shift. These measurements: (1) yield estimates of target size, shape, and spin vector; (2) place constraints on topography, morphology, and composition of the planetary surface; (3) yield refined estimates of target orbital parameters; (4) reveal the presence of asteroidal satellites.

  11. Measurement of backscattering from sea with an airborne radar at L band

    NASA Astrophysics Data System (ADS)

    Luo, Xianyun; Zhang, Zhongzhi; Yin, Zhiying; Sun, Fang; Kang, Shifeng; Wang, Laibu; Yu, Yunchao; Wen, Fangru

    1998-08-01

    Measurements of electromagnetic backscattering from sea surface at L band have been done with airborne side-looking radar system. Several flights are made for various sea states. Coherent radar data ta HH polarization and some truth data such as wave height, wind velocity and direction, temperature of sea water are recorded. Corner reflectors and active backscattering coefficient can be derived from the radar data and the cinematic data. The result presented in this paper include scattering coefficient and statistical analysis of radar echo with typical probability distribution functions such as Rayleigh, Weibull, Log-normal and K distribution.

  12. The DESDynI Synthetic Aperture Radar Array-Fed Reflector Antenna

    NASA Technical Reports Server (NTRS)

    Chamberlain, Neil; Ghaemi, Hirad; Giersch, Louis; Harcke, Leif; Hodges, Richard; Hoffman, James; Johnson, William; Jordan, Rolando; Khayatian, Behrouz; Rosen, Paul; Sadowy, Gregory; Shaffer, Scott; Shen, Yuhsyen; Veilleux, Louise; Wu, Patrick

    2010-01-01

    DESDynI is a mission being developed by NASA with radar and lidar instruments for Earth-orbit remote sensing. This paper focuses on the design of a largeaperture antenna for the radar instrument. The antenna comprises a deployable reflector antenna and an active switched array of patch elements fed by transmit/ receive modules. The antenna and radar architecture facilitates a new mode of synthetic aperture radar imaging called 'SweepSAR'. A system-level description of the antenna is provided, along with predictions of antenna performance.

  13. Studies on Radar and Non-radar Sensor Networks

    DTIC Science & Technology

    2006-06-15

    selection based on specific applications. References [1] Q . Liang, "Waveform Design and Diversity in Radar Sensor Networks: Theoretical Analysis and...Application to Automatic Target Recognition," submitted to IEEE Trans on Aerospace and Electronic Systems. [2] Q . Liang, "Waveform Design and Diversity in...Sensor Networks, June 2006, New York. [3] Q . Liang, "Radar Sensor Networks: Algorithms for Waveform Design and Diversity with Appli- cation to ATR with

  14. Historical aspects of radar atmospheric dynamics

    NASA Technical Reports Server (NTRS)

    Kato, Susumu

    1989-01-01

    A review of the history of radar techniques which have been applied to atmospheric observation is given. The author starts with ionosphere observation with the ionosonde, symbolizing as it does the earliest history of radar observation, and proceeds to later developments in radar observation such as the use of partial reflection, meteor, and incoherent scatter radars. Mesosphere stratosphere troposphere (MST) radars are discussed in terms of lower atmosphere observation.

  15. Space Radar Image of Mississippi Delta

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a radar image of the Mississippi River Delta where the river enters into the Gulf of Mexico along the coast of Louisiana. This multi-frequency image demonstrates the capability of the radar to distinguish different types of wetlands surfaces in river deltas. This image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on October 2, 1995. The image is centered on latitude 29.3 degrees North latitude and 89.28 degrees West longitude. The area shown is approximately 63 kilometers by 43 kilometers (39 miles by 26 miles). North is towards the upper right of the image. As the river enters the Gulf of Mexico, it loses energy and dumps its load of sediment that it has carried on its journey through the mid-continent. This pile of sediment, or mud, accumulates over the years building up the delta front. As one part of the delta becomes clogged with sediment, the delta front will migrate in search of new areas to grow. The area shown on this image is the currently active delta front of the Mississippi. The migratory nature of the delta forms natural traps for oil and the numerous bright spots along the outside of the delta are drilling platforms. Most of the land in the image consists of mud flats and marsh lands. There is little human settlement in this area due to the instability of the sediments. The main shipping channel of the Mississippi River is the broad red stripe running northwest to southeast down the left side of the image. The bright spots within the channel are ships. The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band vertically transmitted, vertically received; green is C-band vertically transmitted, vertically received; blue is X-band vertically transmitted, vertically received. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars

  16. Fly eye radar or micro-radar sensor technology

    NASA Astrophysics Data System (ADS)

    Molchanov, Pavlo; Asmolova, Olga

    2014-05-01

    To compensate for its eye's inability to point its eye at a target, the fly's eye consists of multiple angularly spaced sensors giving the fly the wide-area visual coverage it needs to detect and avoid the threats around him. Based on a similar concept a revolutionary new micro-radar sensor technology is proposed for detecting and tracking ground and/or airborne low profile low altitude targets in harsh urban environments. Distributed along a border or around a protected object (military facility and buildings, camp, stadium) small size, low power unattended radar sensors can be used for target detection and tracking, threat warning, pre-shot sniper protection and provides effective support for homeland security. In addition it can provide 3D recognition and targets classification due to its use of five orders more pulses than any scanning radar to each space point, by using few points of view, diversity signals and intelligent processing. The application of an array of directional antennas eliminates the need for a mechanical scanning antenna or phase processor. It radically decreases radar size and increases bearing accuracy several folds. The proposed micro-radar sensors can be easy connected to one or several operators by point-to-point invisible protected communication. The directional antennas have higher gain, can be multi-frequency and connected to a multi-functional network. Fly eye micro-radars are inexpensive, can be expendable and will reduce cost of defense.

  17. Graphene-enabled electrically switchable radar-absorbing surfaces.

    PubMed

    Balci, Osman; Polat, Emre O; Kakenov, Nurbek; Kocabas, Coskun

    2015-03-20

    Radar-absorbing materials are used in stealth technologies for concealment of an object from radar detection. Resistive and/or magnetic composite materials are used to reduce the backscattered microwave signals. Inability to control electrical properties of these materials, however, hinders the realization of active camouflage systems. Here, using large-area graphene electrodes, we demonstrate active surfaces that enable electrical control of reflection, transmission and absorption of microwaves. Instead of tuning bulk material property, our strategy relies on electrostatic tuning of the charge density on an atomically thin electrode, which operates as a tunable metal in microwave frequencies. Notably, we report large-area adaptive radar-absorbing surfaces with tunable reflection suppression ratio up to 50 dB with operation voltages <5 V. Using the developed surfaces, we demonstrate various device architectures including pixelated and curved surfaces. Our results provide a significant step in realization of active camouflage systems in microwave frequencies.

  18. Graphene-enabled electrically switchable radar-absorbing surfaces

    NASA Astrophysics Data System (ADS)

    Balci, Osman; Polat, Emre O.; Kakenov, Nurbek; Kocabas, Coskun

    2015-03-01

    Radar-absorbing materials are used in stealth technologies for concealment of an object from radar detection. Resistive and/or magnetic composite materials are used to reduce the backscattered microwave signals. Inability to control electrical properties of these materials, however, hinders the realization of active camouflage systems. Here, using large-area graphene electrodes, we demonstrate active surfaces that enable electrical control of reflection, transmission and absorption of microwaves. Instead of tuning bulk material property, our strategy relies on electrostatic tuning of the charge density on an atomically thin electrode, which operates as a tunable metal in microwave frequencies. Notably, we report large-area adaptive radar-absorbing surfaces with tunable reflection suppression ratio up to 50 dB with operation voltages <5 V. Using the developed surfaces, we demonstrate various device architectures including pixelated and curved surfaces. Our results provide a significant step in realization of active camouflage systems in microwave frequencies.

  19. Radar Scans of the Saturn Rings

    NASA Astrophysics Data System (ADS)

    West, Richard D.; Janssen, Michael A.; Cuzzi, Jeffrey N.; Anderson, Yanhua; Hamilton, Gary; Cassini Radar Team

    2016-10-01

    The Cassini mission is now heading into its last year of observations. Part of the mission plan includes orbits that bring the spacecraft close to Saturn's rings prior to deorbiting into Saturn's atmosphere. These orbits are providing a unique opportunity to obtain backscatter measurements and relatively high-resolution brightness temperature measurements from the rings. We plan to scan the rings with the radar central beam and obtain backscatter measurements as a function of radial distance with some variation of incidence angle. Active mode radar scans are planned for four of the final high inclination orbits that bring the spacecraft close to the rings. These radar observations will be designed to sweep the A through C rings with varying bandwidth chirps selected to optimize the tradeoff between radial resolution and measurement variance. Pulse compression will deliver radial resolutions varying from about 200 m to around 4 km depending on the bandwidth used. These measurements will provide a 1-D profile of backscatter obtained at 2.2 cm wavelength that will complement similar passive profiles obtained at optical, infrared, and microwave wavelengths. This presentation will summarize the detailed designs and tradeoffs made for these observations. Such measurements will further constrain and inform models of the composition and structure of the ring particle distributions. This work is supported by the NASA Cassini Program at JPL - CalTech.

  20. Space Radar Image of Kilauea, Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Data acquired on April 13, 1994 and on October 4, 1994 from the X-band Synthetic Aperture Radar on board the space shuttle Endeavour were used to generate interferometric fringes, which were overlaid on the X-SAR image of Kilauea. The volcano is centered in this image at 19.58 degrees north latitude and 155.55 degrees west longitude. The image covers about 9 kilometers by 13 kilometers (5.6 miles by 8 miles). The X-band fringes correspond clearly to the expected topographic image. The yellow line indicates the area below which was used for the three-dimensional image using altitude lines. The yellow rectangular frame fences the area for the final topographic image. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR. The Instituto Ricerca Elettromagnetismo Componenti Elettronici (IRECE) at the University of Naples was a partner in interferometry analysis.

  1. Space Radar Image of Kilauea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This three-dimensional image of the volcano Kilauea was generated based on interferometric fringes derived from two X-band Synthetic Aperture Radar data takes on April 13, 1994 and October 4, 1994. The altitude lines are based on quantitative interpolation of the topographic fringes. The level difference between neighboring altitude lines is 20 meters (66 feet). The ground area covers 12 kilometers by 4 kilometers (7.5 miles by 2.5 miles). The altitude difference in the image is about 500 meters (1,640 feet). The volcano is located around 19.58 degrees north latitude and 155.55 degrees west longitude. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR. The Instituto Ricerca Elettromagnetismo Componenti Elettronici (IRECE) at the University of Naples was a partner in the interferometry analysis.

  2. Space Radar Image of Central Java, Indonesia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The summits of two large volcanoes in Central Java, Indonesia are shown in the center of this radar image. Lava flows of different ages and surface roughness appear in shades of green and yellow surrounding the summit of Mt. Merbabu (mid-center) and Mt. Merapi (lower center). Mt. Merapi erupted on November 28, 1994 about six weeks after this image was taken. The eruption killed more than 60 people and forced the evacuation of more than 6,000 others. Thousands of other residents were put on alert due to the possibility of volcanic debris mudflows, called lahars, that threatened nearby towns. Mt. Merapi is located approximately 40 kilometers (25 miles) north of Yogyakarta, the capital of Central Java. The older volcano at the top of the image is unnamed. Lake Rawapening is the dark blue feature in the upper right. The light blue area southeast of the lake is the city of Salatiga. Directly south of Salatiga and southeast of Mt. Merapi is the city of Boyolali. Scientists are studying Mt. Merapi as part of the international 'Decade Volcanoes' project, because of its recent activity and potential threat to local populations. The radar data are being used to identify and distinguish a variety of volcanic features. This image was acquired on October 10, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. The image is centered at 7.5 degrees South latitude and 110.5 degrees East longitude and covers an area of 33 kilometers by 65 kilometers (20 miles by 40 miles).

  3. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  4. NASA Radar Images Asteroid Toutatis

    NASA Video Gallery

    This 64-frame movie of asteroid Toutatis was generated from data by Goldstone's Solar System Radar on Dec. 12 and 13, 2012. In the movie clips, the rotation of the asteroid appears faster than it o...

  5. Advanced Borehole Radar for Hydrogeology

    NASA Astrophysics Data System (ADS)

    Sato, M.

    2014-12-01

    Ground Penetrating Radar is a useful tool for monitoring the hydrogeological environment. We have developed GPR systems which can be applied to these purposes, and we will demonstrate examples borehole radar measurements. In order to have longer radar detection range, frequency lower than100MHz has been normally adopted in borehole radar. Typical subsurface fractures of our interests have a few mm aperture and radar resolution is much poorer than a few cm in this frequency range. We are proposing and demonstrating to use radar polarimetry to solve this problem. We have demonstrated that a full-polarimetry borehole radar can be used for characterization of subsurface fractures. Together with signal processing for antenna characteristic compensation to equalize the signal by a dipole antenna and slot antennas, we could demonstrate that polarimetric borehole radar can estimate the surface roughness of subsurface fractures, We believe the surface roughness is closely related to water permeability through the fractures. We then developed a directional borehole radar, which uses optical field sensor. A dipole antenna in a borehole has omni-directional radiation pattern, and we cannot get azimuthal information about the scatterers. We use multiple dipole antennas set around the borehole axis, and from the phase differences, we can estimate the 3-diemnational orientation of subsurface structures. We are using optical electric field sensor for receiver of borehole radar. This is a passive sensor and connected only with optical fibers and does not require any electric power supply to operate the receiver. It has two major advantages; the first one is that the receiver can be electrically isolated from other parts, and wave coupling to a logging cable is avoided. Then, secondary, it can operate for a long time, because it does not require battery installed inside the system. It makes it possible to set sensors in fixed positions to monitor the change of environmental

  6. Solar Radar Astronomy with LOFAR

    NASA Astrophysics Data System (ADS)

    Rodriguez, P.

    2003-04-01

    A new approach to the study of the Sun's corona and its dynamical processes is possible with radar investigations in the frequency range of about 10-50 MHz. The range of electron densities of the solar corona is such that radio waves at these frequencies can provide diagnostic radar echoes of large scale phenomena such as coronal mass ejections (CMEs). We expect that the frequency shift imposed on the echo signal by an earthward-moving CME will provide a direct measurement of the velocity, thereby providing a good estimate of the arrival time at Earth. It is known that CMEs are responsible for the largest geomagnetic storms at Earth, which are capable of causing power grid blackouts, satellite electronic upsets, and degradation of radio communications circuits. Thus, having accurate forecasts of potential CME-initiated geomagnetic storms is of practical space weather interest. New high power transmitting arrays are becoming available, along with proposed modifications to existing research facilities, that will allow the use of radio waves to study the solar corona by the radar echo technique. Of particular interest for such solar radar investigations is the bistatic configuration with the Low Frequency Array (LOFAR). The LOFAR facility will have an effective receiving area of about 1 square km at solar radar frequencies. Such large effective area will provide the receiving antenna gain needed for detailed investigations of solar coronal dynamics. Conservative estimates of the signal-to-noise ratio for solar radar echoes as a function of the integration time required to achieve a specified detection level (e.g., ~ 5 dB) indicate that time resolutions of 10s of seconds can be achieved. Thus, we are able to resolve variations in the solar radar cross section on time scales which will provide new information on the plasma dynamical processes associated with the solar corona, such as CMEs. It is the combination of high transmitted power and large effective receiving

  7. Space Radar Image of Kiluchevskoi, Volcano, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of the area of Kliuchevskoi volcano, Kamchatka, Russia, which began to erupt on September 30, 1994. Kliuchevskoi is the blue triangular peak in the center of the image, towards the left edge of the bright red area that delineates bare snow cover. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 88th orbit on October 5, 1994. The image shows an area approximately 75 kilometers by 100 kilometers (46 miles by 62 miles) that is centered at 56.07 degrees north latitude and 160.84 degrees east longitude. North is toward the bottom of the image. The radar illumination is from the top of the image. The Kamchatka volcanoes are among the most active volcanoes in the world. The volcanic zone sits above a tectonic plate boundary, where the Pacific plate is sinking beneath the northeast edge of the Eurasian plate. The Endeavour crew obtained dramatic video and photographic images of this region during the eruption, which will assist scientists in analyzing the dynamics of the recent activity. The colors in this image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted and vertically received); blue represents the C-band (horizontally transmitted and vertically received). In addition to Kliuchevskoi, two other active volcanoes are visible in the image. Bezymianny, the circular crater above and to the right of Kliuchevskoi, contains a slowly growing lava dome. Tolbachik is the large volcano with a dark summit crater near the upper right edge of the red snow covered area. The Kamchatka River runs from right to left across the bottom of the image. The current eruption of Kliuchevskoi included massive ejections of gas, vapor and ash, which reached altitudes of 15,000 meters (50,000 feet). Melting snow mixed with volcanic ash triggered mud flows on the

  8. Space Radar Image of Kliuchevskoi, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-band seasonal image of the Maly Semlyachik volcano, which is part of the Karymsky volcano group on Kamchatka peninsula, Russia. The image is centered at 54.2 degrees north latitude and 159.6 degrees east longitude. This image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on April 9, 1994, during the first flight of the radar system, and on September 30, 1994, during the second flight. The image channels have been assigned the following colors: red corresponds to data acquired on April 9; green corresponds to data acquired on September 30; and blue corresponds to the ratio between data from April 9 and September 30, 1994. Kamchatka is twice as large as England, Scotland and Wales combined and is home to approximately 470,000 residents. The region is characterized by a chain of volcanoes stretching 800 kilometers (500 miles) across the countryside. Many of the volcanoes, including the active Maly Semlyachik volcano in this image, have erupted during this century. But the most active period in creating the three characteristic craters of this volcano goes back 20,000, 12,000 and 2,000 years ago. The highest summit of the oldest crater reaches about 1,560 meters (1,650 feet). The radar images reveal the geological structures of craters and lava flows in order to improve scientists' knowledge of these sometimes vigorously active volcanoes. This seasonal composite also highlights the ecological differences that have occurred between April and October 1994. In April the whole area was snow-covered and, at the coast, an ice sheet extended approximately 5 kilometers (3 miles) into the sea. The area shown surrounding the volcano is covered by low vegetation much like scrub. Kamchatka also has extensive forests, which belong to the northern frontier of Taiga, the boreal forest ecosystem. This region plays an important role in the world's carbon cycle. Trees require 60 years to

  9. The NASA Polarimetric Radar (NPOL)

    NASA Technical Reports Server (NTRS)

    Petersen, Walter A.; Wolff, David B.

    2013-01-01

    Characteristics of the NASA NPOL S-band dual-polarimetric radar are presented including its operating characteristics, field configuration, scanning capabilities and calibration approaches. Examples of precipitation science data collections conducted using various scan types, and associated products, are presented for different convective system types and previous field campaign deployments. Finally, the NASA NPOL radar location is depicted in its home base configuration within the greater Wallops Flight Facility precipitation research array supporting NASA Global Precipitation Measurement Mission ground validation.

  10. Radar Imaging and Target Identification

    DTIC Science & Technology

    2009-02-09

    Methods in Wave Propagation, Vaxjo, Swe- den. • February 19, 2008, "Radar Imaging", math colloquium, Brigham- Young University. • January 31, 2008...manuscript, namely "Radar detection using sparsely distributed 19 apertures in urban environments", Ling Wang, II- Young Son, Trond Varslot, C. Evren...Coinmun. COM- 20, pp. 774-780, 1972. [24] M. Tomlinson, "New automatic equalizer employing modulo arithmetic," Electron. Lett. 7, pp. 138-139, 1971

  11. Synthetic Aperture Radar Simulation Study

    DTIC Science & Technology

    1984-03-01

    multilook are discussed. A chapter is devoted to elevation and planimetric data bases. In addition, six- teen pictures of SAR images from Hughes Aircraft, as...scans. Figure 5.4-1 is a photograph ot two SAR displays. The tirst display is made up ot six subscans and has a multilook ot one. Note that tading is...dentfi by block number) * Synthetic Aperture Radar ( SAR ) Simulation Study Radar Simulation Data Bases 5/~t. 4th.- Computer Image Generation Display 20

  12. Representing radar QPE and QPF uncertainties using radar ensembles

    NASA Astrophysics Data System (ADS)

    Sempere-Torres, D.; Llort, X.; Roca, J.; Pegram, G.

    2009-09-01

    In the last years, new comprehension of the physics underlying the radar measurements as well as new technological advancements have allowed radar community to propose better algorithms and methodologies and significant advancements have been achieved in improving Quantitative Precipitation Estimates (QPE) and Quantitative Precipitation forecasting (QPF) by radar. Thus the study of the 2D uncertainties field associated to these estimates has become an important subject, specially to enhance the use of radar QPE and QPF in hydrological studies, as well as in providing a reference for satellite precipitations measurements. In this context the use of radar-based rainfall ensembles (i.e. equiprobable rainfall field scenarios generated to be compatible with the observations/forecasts and with the inferred structure of the uncertainties) has been seen as an extremely interesting tool to represent their associated uncertainties. The generation of such radar ensembles requires first the full characterization of the 3D field of associated uncertainties (2D spatial plus temporal), since rainfall estimates show an error structure highly correlated in space and time. A full methodology to deal with this kind of radar-based rainfall ensembles is presented. Given a rainfall event, the 2D uncertainty fields associated to the radar estimates are defined for every time step using a benchmark, or reference field, based on the best available estimate of the rainfall field. This benchmark is built using an advanced non parametric interpolation of a dense raingauge network able to use the spatial structure provided by the radar observations, and is confined to the region in which this combination could be taken as a reference measurement (Velasco-Forero et al. 2008, doi:10.1016/j.advwatres.2008.10.004). Then the spatial and temporal structures of these uncertainty fields are characterized and a methodology to generate consistent multiple realisations of them is used to generate the

  13. Space Radar Image of North Sea, Germany

    NASA Technical Reports Server (NTRS)

    1994-01-01

    swiftly than is currently possible. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  14. Space Radar Image of Altona, Manitoba, Canada

    NASA Technical Reports Server (NTRS)

    1994-01-01

    the magenta indicate differences in the degree of soil moisture change and differences in surface roughness. This seasonal composite demonstrates the sensitivity of radar to changes in agricultural surface conditions such as soil moisture, tillage, cropping and harvesting. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  15. Radar Studies on Kamb Ice Stream

    NASA Astrophysics Data System (ADS)

    Pettersson, R.; Osterhouse, D. J.; Mulhausen, A.; Welch, B. C.; Strandli, C. W.; Jacobel, R. W.

    2006-12-01

    by comparison with ground-based radar data we collected in the late 1980's. These studies depict changes in the horizontal strain rate as ice passes around the sticky spot. Bed topography, rheological properties and internal layer characteristics will all provide constraints to models describing the evolution and possible future of ice flow in KIS. Two profiles crossing from the actively-flowing region of highly reflective bed into the northern margin of KIS (defined by strong velocity gradients) show continuous internal stratigraphy across the margin, indicating that substantial volumes of ice are still flowing across the margin into KIS in this area. A 250 km long longitudinal profile has also been acquired following a flow line down stream KIS and then crossing the margin up to Siple Dome summit. Along the profile we have traced internal layers to the KIS north margin. On the Siple Dome side, we have also traced internal stratigraphy to the site for the ice core drilled at Siple Dome summit, allowing us to date the internal layers. However the high shear that has taken place across this margin prevents us from convincingly tying layers in the ice stream to the dated Siple Dome stratigraphy.

  16. Hydrologic applications of weather radar

    NASA Astrophysics Data System (ADS)

    Seo, Dong-Jun; Habib, Emad; Andrieu, Hervé; Morin, Efrat

    2015-12-01

    By providing high-resolution quantitative precipitation information (QPI), weather radars have revolutionized hydrology in the last two decades. With the aid of GIS technology, radar-based quantitative precipitation estimates (QPE) have enabled routine high-resolution hydrologic modeling in many parts of the world. Given the ever-increasing need for higher-resolution hydrologic and water resources information for a wide range of applications, one may expect that the use of weather radar will only grow. Despite the tremendous progress, a number of significant scientific, technological and engineering challenges remain to realize its potential. New challenges are also emerging as new areas of applications are discovered, explored and pursued. The purpose of this special issue is to provide the readership with some of the latest advances, lessons learned, experiences gained, and science issues and challenges related to hydrologic applications of weather radar. The special issue features 20 contributions on various topics which reflect the increasing diversity as well as the areas of focus in radar hydrology today. The contributions may be grouped as follows: Radar QPE (Kwon et al.; Hall et al.; Chen and Chandrasekar; Seo and Krajewski; Sandford).

  17. Coded continuous wave meteor radar

    NASA Astrophysics Data System (ADS)

    Vierinen, Juha; Chau, Jorge L.; Pfeffer, Nico; Clahsen, Matthias; Stober, Gunter

    2016-03-01

    The concept of a coded continuous wave specular meteor radar (SMR) is described. The radar uses a continuously transmitted pseudorandom phase-modulated waveform, which has several advantages compared to conventional pulsed SMRs. The coding avoids range and Doppler aliasing, which are in some cases problematic with pulsed radars. Continuous transmissions maximize pulse compression gain, allowing operation at lower peak power than a pulsed system. With continuous coding, the temporal and spectral resolution are not dependent on the transmit waveform and they can be fairly flexibly changed after performing a measurement. The low signal-to-noise ratio before pulse compression, combined with independent pseudorandom transmit waveforms, allows multiple geographically separated transmitters to be used in the same frequency band simultaneously without significantly interfering with each other. Because the same frequency band can be used by multiple transmitters, the same interferometric receiver antennas can be used to receive multiple transmitters at the same time. The principles of the signal processing are discussed, in addition to discussion of several practical ways to increase computation speed, and how to optimally detect meteor echoes. Measurements from a campaign performed with a coded continuous wave SMR are shown and compared with two standard pulsed SMR measurements. The type of meteor radar described in this paper would be suited for use in a large-scale multi-static network of meteor radar transmitters and receivers. Such a system would be useful for increasing the number of meteor detections to obtain improved meteor radar data products.

  18. Development of High Altitude UAV Weather Radars for Hurricane Research

    NASA Technical Reports Server (NTRS)

    Heymsfield, Gerald; Li, Li-Hua

    2005-01-01

    precipitation, the surface return over a single 360 degree sweep over -25 h-diameter region provides information on the surface wind speed and direction within the scan circle. In precipitation regions, the conical scan with appropriate mapping and analysis provides the 3D structure of reflectivity beneath the plane and the horizontal winds. The use of conical scanning in hurricanes has recently been demonstrated for measuring inner core winds with the IWRAP system flying on the NOAA P3's. In this presentation, we provide a description of the URAD system hardware, status, and future plans. In addition to URAD, NASA SBIR activity is supporting a Phase I study by Remote Sensing Solutions and the University of Massachusetts for a dual-frequency IWRAP for a high altitude UAV that utilizes solid state transmitters at 14 and 35 GHz, the same frequencies that are planned for the radar on the Global Precipitation System satellite. This will be discussed elsewhere at the meeting.

  19. Observations of the marine environment from spaceborne side-looking real aperture radars

    NASA Technical Reports Server (NTRS)

    Kalmykov, A. I.; Velichko, S. A.; Tsymbal, V. N.; Kuleshov, Yu. A.; Weinman, J. A.; Jurkevich, I.

    1993-01-01

    Real aperture, side looking X-band radars have been operated from the Soviet Cosmos-1500, -1602, -1766 and Ocean satellites since 1984. Wind velocities were inferred from sea surface radar scattering for speeds ranging from approximately 2 m/s to those of hurricane proportions. The wind speeds were within 10-20 percent of the measured in situ values, and the direction of the wind velocity agreed with in situ direction measurements within 20-50 deg. Various atmospheric mesoscale eddies and tropical cyclones were thus located, and their strengths were inferred from sea surface reflectivity measurements. Rain cells were observed over both land and sea with these spaceborne radars. Algorithms to retrieve rainfall rates from spaceborne radar measurements were also developed. Spaceborne radars have been used to monitor various marine hazards. For example, information derived from those radars was used to plan rescue operations of distressed ships trapped in sea ice. Icebergs have also been monitored, and oil spills were mapped. Tsunamis produced by underwater earthquakes were also observed from space by the radars on the Cosmos 1500 series of satellites. The Cosmos-1500 satellite series have provided all weather radar imagery of the earths surface to a user community in real time by means of a 137.4 MHz Automatic Picture Transmission channel. This feature enabled the radar information to be used in direct support of Soviet polar maritime activities.

  20. RFI Mitigation and Detection for the SMAP Radar

    NASA Technical Reports Server (NTRS)

    Chan, Samuel; Fischman, Mark; Spencer, Michael

    2011-01-01

    The planned Soil Moisture Active Passive (SMAP) mission will use both active radar and passive radiometer instruments at L-Band to measure and monitor both soilmoisture and freeze/thaw state globally. The frequency band allocated for the SMAP radar is shared with the Global Navigation Satellite Systems and ground-basedradiolocation services. Signals from those users present significant sources of anthropogenic radio frequency interference (RFI) which contaminate the radarmeasurements. To mitigate RFI, the radar is designed with tunable operating frequency, which allows the center frequency to be tuned to avoid RFI. The filtering scheme in the receiver is configured to get a high level of RFI suppression. To meet the high accuracy measurement requirements, RFI detection and correction will be required during ground data processing. Some candidate algorithms have been evaluated, and they have been tested against simulated SMAP data derived from the PALSAR data.

  1. Laser radar observation of the polar stratospheric aerosol layer

    NASA Technical Reports Server (NTRS)

    Iwasaka, Y.; Hirasawa, T.; Fukunishi, H.; Fujiwara, M.; Fujii, R.; Miyaoka, H.

    1985-01-01

    The polar stratosphere has been speculated to be an active sink region of various stratospheric materials; ozone, water vapor, NOX, aerosol particles and so on, but this process is not theoretically and/or observationally made clear. The observation of the polar stratospheric aerosol layer using laser radar certainly contributes to the study of the global transport of these stratospheric minor constituents. In addition to this, from the viewpoint of aerosol science, there may be many interesting phenomena which cannot be found in the stratosphere at mid and low latitudes; the effect of precipitation of high energy molecules and atoms, of very cold winter stratosphere, of very cold mesopause in summer. Laser radar observation is one of the main activities of the Antarctic Middle Atmosphere (AMA) project at Syowa Station (69.00 deg S, 39.35 deg E), Antarctica since May 1983. Laser radar measurement at Syowa Station is discussed in detail.

  2. Online clustering algorithms for radar emitter classification.

    PubMed

    Liu, Jun; Lee, Jim P Y; Senior; Li, Lingjie; Luo, Zhi-Quan; Wong, K Max

    2005-08-01

    Radar emitter classification is a special application of data clustering for classifying unknown radar emitters from received radar pulse samples. The main challenges of this task are the high dimensionality of radar pulse samples, small sample group size, and closely located radar pulse clusters. In this paper, two new online clustering algorithms are developed for radar emitter classification: One is model-based using the Minimum Description Length (MDL) criterion and the other is based on competitive learning. Computational complexity is analyzed for each algorithm and then compared. Simulation results show the superior performance of the model-based algorithm over competitive learning in terms of better classification accuracy, flexibility, and stability.

  3. Space Radar Image of Manaus, Brazil

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This false-color L-band image of the Manaus region of Brazil was acquired by the Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on orbit 46 of the mission. The area shown is approximately 8 kilometers by 40 kilometers (5 by 25 miles). At the top of the image are the Solimoes and Rio Negro rivers just before they combine at Manaus to form the Amazon River. The image is centered at about 3 degrees south latitude, and 61 degrees west longitude. The false colors are created by displaying three L-band polarization channels; red areas correspond to high backscatter at HH polarization, while green areas exhibit high backscatter at HV polarization. Blue areas show low returns at VV polarization; hence the bright blue colors of the smooth river surfaces. Using this coloring scheme, green areas in the image are heavily forested, while blue areas are either cleared forest or open water. The yellow and red areas are flooded forest. Between Rio Solimoes and Rio Negro a road can be seen running from some cleared areas (visible as blue rectangles north of Rio Solimoes) north towards a tributary of Rio Negro. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio

  4. All-digital radar architecture

    NASA Astrophysics Data System (ADS)

    Molchanov, Pavlo A.

    2014-10-01

    All digital radar architecture requires exclude mechanical scan system. The phase antenna array is necessarily large because the array elements must be co-located with very precise dimensions and will need high accuracy phase processing system for aggregate and distribute T/R modules data to/from antenna elements. Even phase array cannot provide wide field of view. New nature inspired all digital radar architecture proposed. The fly's eye consists of multiple angularly spaced sensors giving the fly simultaneously thee wide-area visual coverage it needs to detect and avoid the threats around him. Fly eye radar antenna array consist multiple directional antennas loose distributed along perimeter of ground vehicle or aircraft and coupled with receiving/transmitting front end modules connected by digital interface to central processor. Non-steering antenna array allows creating all-digital radar with extreme flexible architecture. Fly eye radar architecture provides wide possibility of digital modulation and different waveform generation. Simultaneous correlation and integration of thousands signals per second from each point of surveillance area allows not only detecting of low level signals ((low profile targets), but help to recognize and classify signals (targets) by using diversity signals, polarization modulation and intelligent processing. Proposed all digital radar architecture with distributed directional antenna array can provide a 3D space vector to the jammer by verification direction of arrival for signals sources and as result jam/spoof protection not only for radar systems, but for communication systems and any navigation constellation system, for both encrypted or unencrypted signals, for not limited number or close positioned jammers.

  5. Cassini RADAR Observations of Saturn's Largest Moon, Titan

    NASA Astrophysics Data System (ADS)

    Hayes, A. G., Jr.; Mastrogiuseppe, M.; Lunine, J. I.; Lorenz, R. D.; Wall, S. D.; Stiles, B. W.; Kirk, R. L.; Elachi, C.; Hofgartner, J. D.; Birch, S. P.; Le Gall, A. A.; Poggiali, V.; Zebker, H. A.

    2015-12-01

    The Cassini RADAR is a versatile instrument capable of operating in imaging, altimetry, scatterometry, radiometry, and, most recently, sounding modes. Despite vastly different material properties and environmental conditions, Titan's methane-based hydrologic system drives climatic and geologic processes that result in morphologic features with striking similarity to terrestrial counterparts, including vast equatorial dune fields, well-organized channel networks that route material through erosional and depositional landscapes defining source-to-sink sediment transport systems, and, perhaps most astonishingly, lakes and seas filled with liquid hydrocarbons. Using its various operating modes, the Cassini RADAR has provided a wealth of information regarding Titan's active surface-atmosphere system. In Synthetic Aperture Radar (SAR) mode, the RADAR has unveiled Titan's surface by producing backscatter maps with pixel scales of ~300 m. In altimetry mode, the RADAR has shown the elevation profile of surface features, including the liquid elevation of Titan's lakes and seas, revealed the roughness characteristics of the surface, and constrained the global shape. Most recently, the altimetry mode has doubled as a radar sounder that has successfully probed the depth and absorptivity of the lakes and seas. Data from the scatterometry and radiometry modes have been used to constrain material properties, including dielectric constants and volume scattering fractions, surface texture, and derive seasonal and diurnal temperature variations. Collectively, these datasets have revealed Titan's strange yet familiar nature, and demonstrated that it is one of the most compelling targets in our solar system. During our presentation, we will summarize these capabilities and review some of the most specular discoveries made by the Cassini RADAR.

  6. Wrist Pulse Rate Monitor Using Self-Injection-Locked Radar Technology

    PubMed Central

    Wang, Fu-Kang; Tang, Mu-Cyun; Su, Sheng-Chao; Horng, Tzyy-Sheng

    2016-01-01

    To achieve sensitivity, comfort, and durability in vital sign monitoring, this study explores the use of radar technologies in wearable devices. The study first detected the respiratory rates and heart rates of a subject at a one-meter distance using a self-injection-locked (SIL) radar and a conventional continuous-wave (CW) radar to compare the sensitivity versus power consumption between the two radars. Then, a pulse rate monitor was constructed based on a bistatic SIL radar architecture. This monitor uses an active antenna that is composed of a SIL oscillator (SILO) and a patch antenna. When attached to a band worn on the subject’s wrist, the active antenna can monitor the pulse on the subject’s wrist by modulating the SILO with the associated Doppler signal. Subsequently, the SILO’s output signal is received and demodulated by a remote frequency discriminator to obtain the pulse rate information. PMID:27792176

  7. Wrist Pulse Rate Monitor Using Self-Injection-Locked Radar Technology.

    PubMed

    Wang, Fu-Kang; Tang, Mu-Cyun; Su, Sheng-Chao; Horng, Tzyy-Sheng

    2016-10-26

    To achieve sensitivity, comfort, and durability in vital sign monitoring, this study explores the use of radar technologies in wearable devices. The study first detected the respiratory rates and heart rates of a subject at a one-meter distance using a self-injection-locked (SIL) radar and a conventional continuous-wave (CW) radar to compare the sensitivity versus power consumption between the two radars. Then, a pulse rate monitor was constructed based on a bistatic SIL radar architecture. This monitor uses an active antenna that is composed of a SIL oscillator (SILO) and a patch antenna. When attached to a band worn on the subject's wrist, the active antenna can monitor the pulse on the subject's wrist by modulating the SILO with the associated Doppler signal. Subsequently, the SILO's output signal is received and demodulated by a remote frequency discriminator to obtain the pulse rate information.

  8. Space Radar Image of Long Valley, California in 3-D

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This three-dimensional perspective view of Long Valley, California was created from data taken by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar on board the space shuttle Endeavour. This image was constructed by overlaying a color composite SIR-C radar image on a digital elevation map. The digital elevation map was produced using radar interferometry, a process by which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The interferometry data were acquired on April 13,1994 and on October 3, 1994, during the first and second flights of the SIR-C/X-SAR instrument. The color composite radar image was taken in October and was produced by assigning red to the C-band (horizontally transmitted and vertically received) polarization; green to the C-band (vertically transmitted and received) polarization; and blue to the ratio of the two data sets. Blue areas in the image are smooth and yellow areas are rock outcrops with varying amounts of snow and vegetation. The view is looking north along the northeastern edge of the Long Valley caldera, a volcanic collapse feature created 750,000 years ago and the site of continued subsurface activity. Crowley Lake is the large dark feature in the foreground. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are

  9. Radar Mosaic of Africa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is an image of equatorial Africa, centered on the equator at longitude 15degrees east. This image is a mosaic of almost 4,000 separate images obtained in 1996 by the L-band imaging radar onboard the Japanese Earth Resources Satellite. Using radar to penetrate the persistent clouds prevalent in tropical forests, the Japanese Earth Resources Satellite was able for the first time to image at high resolution this continental scale region during single flooding seasons. The area shown covers about 7.4 million square kilometers (2.8 million square miles) of land surface, spans more than 5,000 kilometers(3,100 miles) east and west and some 2,000 kilometers (1,240 miles) north and south. North is up in this image. At the full resolution of the mosaic (100 meters or 330 feet), this image is more than 500 megabytes in size, and was processed from imagery totaling more than 60 gigabytes.

    Central Africa was imaged twice in 1996, once between January and March, which is the major low-flood season in the Congo Basin, and once between October and November, which is the major high-flood season in the Congo Basin. The red color corresponds to the data from the low-flood season, the green to the high-flood season, and the blue to the 'texture' of the low-flood data. The forests appear green as a result, the flooded and palm forests, as well as urban areas, appear yellow, the ocean and lakes appear black, and savanna areas appear blue, black or green, depending on the savanna type, surface topography and other factors. The areas of the image that are black and white were mapped only between January and March 1996. In these areas, the black areas are savanna or open water, the gray are forests, and the white areas are flooded forests or urban areas. The Congo River dominates the middle of the image, where the nearby forests that are periodically flooded by the Congo and its tributaries stand out as yellow. The Nile River flows north from Lake Victoria in the middle right of

  10. Space Radar Image of Oetzal, Austria

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This image is a false-color composite of Oetzal, Austria located in the Central Alps centered at 46.8 degrees north latitude, 10.70 degrees east longitude, at the border between Switzerland (top), Italy (left) and Austria (right and bottom). The area shown is 50 kilometers (30 miles) south of Innsbruck, Austria. This image was acquired by the Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 14th orbit. Oetztal is a SIR-C/X-SAR hydrology supersite. Approximately one quarter of this image is covered by glaciers, the largest of which, Gepatschferner, is visible as a triangular yellow patch in the center of the scene. The summits of the main peaks reach elevations between 3,500 and 3,768 meters (11,500 and 12,362 feet) above sea level. The tongues of the glaciers are descending from elevated plateaus down into narrow valleys which were formed during the last ice age. This color image was produced in C-band using multi-polarization information (red=CHV, green=CVV,blue=CVV/CHV). The blue areas are lakes (Gepatsch dam at center right; Lake Muta at top right) and glacier ice. The yellow areas are slopes facing the radar and areas of dry snow. Purple corresponds to slopes facing away from the radar. Yellow in the valley bottom corresponds to tree covered areas. There is 30 to 50 centimeters (12 to 20 inches) of dry, fresh snow on the glaciers, and about 10 centimeters (4 inches) in the valley at the city of Vent, Austria (center). At these data were taken, the weather was cold, with snow and thick fog. The entire area would appear white to an optical sensor because it is all covered under a winter snowpack. Researchers are interested in Oetztal because knowing how glaciers shrink and grow over time is an important indication of climatic change. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth (MTPE). The radars illuminate Earth with

  11. Space Radar Image of Mammoth Mountain, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This false-color composite radar image of the Mammoth Mountain area in the Sierra Nevada Mountains, California, was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on its 67th orbit on October 3, 1994. The image is centered at 37.6 degrees north latitude and 119.0 degrees west longitude. The area is about 39 kilometers by 51 kilometers (24 miles by 31 miles). North is toward the bottom, about 45 degrees to the right. In this image, red was created using L-band (horizontally transmitted/vertically received) polarization data; green was created using C-band (horizontally transmitted/vertically received) polarization data; and blue was created using C-band (horizontally transmitted and received) polarization data. Crawley Lake appears dark at the center left of the image, just above or south of Long Valley. The Mammoth Mountain ski area is visible at the top right of the scene. The red areas correspond to forests, the dark blue areas are bare surfaces and the green areas are short vegetation, mainly brush. The purple areas at the higher elevations in the upper part of the scene are discontinuous patches of snow cover from a September 28 storm. New, very thin snow was falling before and during the second space shuttle pass. In parallel with the operational SIR-C data processing, an experimental effort is being conducted to test SAR data processing using the Jet Propulsion Laboratory's massively parallel supercomputing facility, centered around the Cray Research T3D. These experiments will assess the abilities of large supercomputers to produce high throughput Synthetic Aperture Radar processing in preparation for upcoming data-intensive SAR missions. The image released here was produced as part of this experimental effort. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR)are part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed

  12. Space Radar Image of Weddell Sea Ice

    NASA Technical Reports Server (NTRS)

    1994-01-01

    -ice growth perhaps 5 to 10 centimeters (2 to 4 inches) thick. The more extensive dark zones are covered by a slightly thicker layer of smooth, level ice up to 70 centimeters (28 inches) thick. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR.

  13. Space Radar Image of Flevoland, Netherlands

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a three-frequency false color image of Flevoland, The Netherlands, centered at 52.4 degrees north latitude, 5.4 degrees east longitude. This image was acquired by the Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard space shuttle Endeavour on April 14, 1994. It was produced by combining data from the X-band, C-band and L-band radars. The area shown is approximately 25 kilometers by 28 kilometers (15-1/2 by 17-1/2 miles). Flevoland, which fills the lower two-thirds of the image, is a very flat area that is made up of reclaimed land that is used for agriculture and forestry. At the top of the image, across the canal from Flevoland, is an older forest shown in red; the city of Harderwijk is shown in white on the shore of the canal. At this time of the year, the agricultural fields are bare soil, and they show up in this image in blue. The changes in the brightness of the blue areas are equal to the changes in roughness. The dark blue areas are water and the small dots in the canal are boats. This SIR-C/X-SAR supersite is being used for both calibration and agricultural studies. Several soil and crop ground-truth studies will be conducted during the shuttle flight. In addition, about 10calibration devices and 10 corner reflectors have been deployed to calibrate and monitor the radar signal. One of these transponders can be seen as a bright star in the lower right quadrant of the image. This false-color image was made using L-band total power in the red channel, C-band total power in the green channel, and X-band VV polarization in the blue channel. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be

  14. Space Radar Image of Houston, Texas

    NASA Technical Reports Server (NTRS)

    1994-01-01

    -C/X-band Synthetic Aperture Radar(SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI) with the Deutsche Forschungsanstalt fuer luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  15. Bistatic synthetic aperture radar

    NASA Astrophysics Data System (ADS)

    Yates, Gillian

    Synthetic aperture radar (SAR) allows all-weather, day and night, surface surveillance and has the ability to detect, classify and geolocate objects at long stand-off ranges. Bistatic SAR, where the transmitter and the receiver are on separate platforms, is seen as a potential means of countering the vulnerability of conventional monostatic SAR to electronic countermeasures, particularly directional jamming, and avoiding physical attack of the imaging platform. As the receiving platform can be totally passive, it does not advertise its position by RF emissions. The transmitter is not susceptible to jamming and can, for example, operate at long stand-off ranges to reduce its vulnerability to physical attack. This thesis examines some of the complications involved in producing high-resolution bistatic SAR imagery. The effect of bistatic operation on resolution is examined from a theoretical viewpoint and analytical expressions for resolution are developed. These expressions are verified by simulation work using a simple 'point by point' processor. This work is extended to look at using modern practical processing engines for bistatic geometries. Adaptations of the polar format algorithm and range migration algorithm are considered. The principal achievement of this work is a fully airborne demonstration of bistatic SAR. The route taken in reaching this is given, along with some results. The bistatic SAR imagery is analysed and compared to the monostatic imagery collected at the same time. Demonstrating high-resolution bistatic SAR imagery using two airborne platforms represents what I believe to be a European first and is likely to be the first time that this has been achieved outside the US (the UK has very little insight into US work on this topic). Bistatic target characteristics are examined through the use of simulations. This also compares bistatic imagery with monostatic and gives further insight into the utility of bistatic SAR.

  16. Radar ''Sail'' satellite concept and design

    NASA Astrophysics Data System (ADS)

    Aguttes, Jean.-Paul; Sombrin, Jacques; Conde, Eric; Chaubet, Michel; Sebbag, Isabelle; Bousquet, Pierre

    2000-05-01

    The RADAR SAIL concept is based on the use of a rectangular antenna lying in the dawn-dusk orbital plane with the length (along speed vector) smaller than the height. Such geometry makes it possible to place the solar cells on the back of the antenna, to use gravity gradient stabilisation, and (optionally) to implement multipath-free GPS interferometric measurement of the antenna deformation thus allowing structural relaxation. Less obviously, the geometry favours the RADAR design too, by allowing grating lobes and therefore a lower density of built-in electronic in the active antenna. The antenna can be thin and packed for launch inside a cylinder-shaped bus having pyrotechnic doors for the antenna deployment and bearing the rest of the payload and the service equipment. With respect to a standard design of high performance missions, cost savings come from the bus, whose functions (AOCS, power supply) are simplified, from the launch since the mass budget and the stowing configuration become compatible with medium size rockets (LLV2/3, DELTA-LITE, LM-4…), and from the active antenna built-in electronics. Moreover, long satellite life-time can be achieved (10 years instead of 5). The RADAR SAIL concept is all the more cost effective when the mission requires a large, high and short antenna, i.e. high resolution (<5 m), low frequency band (L or S or even P), high revisiting, multiple frequencies. Mission implementation and funding can be favored by the new capability to share the satellite between autonomous regional operators. Combined with ground DBF (digital beam forming) technique, the concept allows extremely simple and low cost missions providing a fixed wide swath (10 to 15 m resolution within 500 km to 1000 km swath) for systematic surveillance or monitoring.

  17. Interdisciplinary Earth Science Applications Using Satellite Radar Altimetry

    NASA Astrophysics Data System (ADS)

    Kuo, C.; Shum, C.; Lee, H.; Dai, C.; Yi, Y.

    2012-12-01

    Satellite altimetry was conceived as a space geodetic concept for ocean surface topography mapping in the NASA-sponsored 1969 Williamstown, MA Conference, and was tested as part of the passive and active radar payload (S192), along with a radiometer and a scatterometer, on Skylab-1 in May 14, 1973. Since then, numerous radar and laser satellite altimetry missions orbiting/flying-by the Earth, Mars, Mercury, Titan and the Moon have been launched, evolving from the original scientific objective of marine gravity field mapping to a geodetic tool to address interdisciplinary Earth and planetary sciences. The accuracy of the radar altimeter has improved from 0.9 m RMS for the S-192 Skylab Ku-band compressed-pulse altimeter, to 2 cm RMS (2 second average) for the dual-frequency pulse-limited radar altimetry and associated sensors onboard TOPEX/POSEIDON. Satellite altimetry has evolved into a unique cross-disciplinary geodetic tool in addressing contemporary Earth science problems including sea-level rise, large-scale general ocean circulation, ice-sheet mass balance, terrestrial hydrology, and bathymetry. Here we provide a concise review and describe specific results on the additional recent innovative and unconventional applications of interdisciplinary science research using satellite radar altimetry, including geodynamics, land subsidence, snow depth, wetland and cold region hydrology.

  18. Technology: Photonics illuminates the future of radar

    NASA Astrophysics Data System (ADS)

    McKinney, Jason D.

    2014-03-01

    The first implementation of a fully photonics-based coherent radar system shows how photonic methods for radio-frequency signal generation and measurement may facilitate the development of software-defined radar systems. See Letter p.341

  19. Obstacle penetrating dynamic radar imaging system

    DOEpatents

    Romero, Carlos E.; Zumstein, James E.; Chang, John T.; Leach, Jr.. Richard R.

    2006-12-12

    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  20. Meteorological radar facility. Part 1: System design

    NASA Technical Reports Server (NTRS)

    Brassaw, L. L., Jr.; Hamren, S. D.; Mullins, W. H.; Schweitzer, B. P.

    1976-01-01

    A compilation of information regarding systems design of space shuttles used in meteorological radar probes is presented. Necessary radar equipment is delineated, while space system elements, calibration techniques, antenna systems and other subsystems are reviewed.

  1. German Radar Observation Shuttle Experiment (ROSE)

    NASA Technical Reports Server (NTRS)

    Sleber, A. J.; Hartl, P.; Haydn, R.; Hildebrandt, G.; Konecny, G.; Muehlfeld, R.

    1984-01-01

    The success of radar sensors in several different application areas of interest depends on the knowledge of the backscatter of radar waves from the targets of interest, the variance of these interaction mechanisms with respect to changing measurement parameters, and the determination of the influence of he measuring systems on the results. The incidence-angle dependency of the radar cross section of different natural targets is derived. Problems involved by the combination of data gained with different sensors, e.g., MSS-, TM-, SPOTand SAR-images are analyzed. Radar cross-section values gained with ground-based radar spectrometers and spaceborne radar imaging, and non-imaging scatterometers and spaceborne radar images from the same areal target are correlated. The penetration of L-band radar waves into vegetated and nonvegetated surfaces is analyzed.

  2. Fiber optic coherent laser radar 3d vision system

    SciTech Connect

    Sebastian, R.L.; Clark, R.B.; Simonson, D.L.

    1994-12-31

    Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic of coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  3. Multifrequency radar imaging of ash plumes: an experiment at Stromboli

    NASA Astrophysics Data System (ADS)

    Donnadieu, Franck; Freret-Lorgeril, Valentin; Delanoë, Julien; Vinson, Jean-Paul; Peyrin, Frédéric; Hervier, Claude; Caudoux, Christophe; Van Baelen, Joël; Latchimy, Thierry

    2016-04-01

    Volcanic ash emissions in the atmosphere are hazardous to aviation while ash fallout affects people and human activities and may cause damage to infrastructures and economic losses. In the framework of the French Government Laboratory of Excellence ClerVolc initiative, an experiment was carried out on Stromboli volcano (Italy), between 28 September and 4 October 2015. The aim was to retrieve various physical properties of the ash plumes, especially the mass loading parameters which are critical for the modelling of ash dispersal. We used a complementary set of cutting edge techniques recording in different bands of the electromagnetic spectrum. The innovative instrument setup consisted in three radars, hyperspectral thermal infrared and dual-band UV cameras, a mini DOAS-Flyspec and a multigas sensor. A drone equipped with differential GPS was flown near the ash plumes with several sensors including SO2, CO2 and particle counter. We mainly focus on radar measurements of over 200 ash plumes and present some preliminary comparisons at three frequencies. The BASTA Doppler radar at 95 GHz, originally designed for atmospheric studies, was deployed at about 2.2 km in slant distance from the eruptive craters. It was configured to observe volumes above one of the active craters with a spatio-temporal resolution of 12.5 m and 1 s. From the same location, a 1.2 GHz volcano Doppler radar (VOLDORAD) was recording the signature of ballistics and small lapilli at 0.15 s in 60 m-deep volumes. In addition, a commercial 24 GHz micro rain Doppler radar (MRR) simultaneously recorded activity from the Rochette station, at 400 to 650 m from the active craters with a sampling rate of 10 s and a resolution of 25 m. The latter was pointing almost perpendicularly to the other radar beams. Reflectivity factors were measured inside the ash plume above the source vent by the BASTA radar (3 mm wavelength) spanning -9 to +21 dBZ. Fallout could sometimes be tracked during several minutes within

  4. Space Radar Image of Kliuchevskoi Volcano, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of the Kliuchevskoi volcano, Kamchatka, Russia, which began to erupt on September 30, 1994. Kliuchevskoi is the bright white peak surrounded by red slopes in the lower left portion of the image. The image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on its 25th orbit on October 1, 1994. The image shows an area approximately 30 kilometers by 60 kilometers (18.5 miles by 37 miles) that is centered at 56.18 degrees north latitude and 160.78 degrees east longitude. North is toward the top of the image. The Kamchatka volcanoes are among the most active volcanoes in the world. The volcanic zone sits above a tectonic plate boundary, where the Pacific plate is sinking beneath the northeast edge of the Eurasian plate. The Endeavour crew obtained dramatic video and photographic images of this region during the eruption, which will assist scientists in analyzing the dynamics of the current activity. The colors in this image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted and vertically received); blue represents the C-band (horizontally transmitted and vertically received). The Kamchatka River runs from left to right across the image. An older, dormant volcanic region appears in green on the north side of the river. The current eruption included massive ejections of gas, vapor and ash, which reached altitudes of 20,000 meters (65,000 feet). New lava flows are visible on the flanks of Kliuchevskoi, appearing yellow/green in the image, superimposed on the red surfaces in the lower center. Melting snow triggered mudflows on the north flank of the volcano, which may threaten agricultural zones and other settlements in the valley to the north. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars

  5. Space Radar Image of Kilauea, Hawaii

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This color composite C-band and L-band image of the Kilauea volcano on the Big Island of Hawaii was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) flying on space shuttle Endeavour. The city of Hilo can be seen at the top. The image shows the different types of lava flows around the crater Pu'u O'o. Ash deposits which erupted in 1790 from the summit of Kilauea volcano show up as dark in this image, and fine details associated with lava flows which erupted in 1919 and 1974 can be seen to the south of the summit in an area called the Ka'u Desert. In addition, the other historic lava flows created in 1881 and 1984 from Mauna Loa volcano (out of view to the left of this image) can be easily seen despite the fact that the surrounding area is covered by forest. Such information will be used to map the extent of such flows, which can pose a hazard to the subdivisions of Hilo. Highway 11 is the linear feature running from Hilo to the Kilauea volcano. The Kilauea volcano has been almost continuously active for more than the last 11 years. Field teams that were on the ground specifically to support these radar observations report that there was vigorous surface activity about 400 meters (one-quarter mile) inland from the coast. A moving lava flow about 200 meters (660 feet) in length was observed at the time of the shuttle overflight, raising the possibility that subsequent images taken during this mission will show changes in the landscape. This image is centered at 19.2 degrees north latitude and 155.2 degrees west longitude. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific

  6. Space Radar Image of Colombian Volcano

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a radar image of a little known volcano in northern Colombia. The image was acquired on orbit 80 of space shuttle Endeavour on April 14, 1994, by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The volcano near the center of the image is located at 5.6 degrees north latitude, 75.0 degrees west longitude, about 100 kilometers (65 miles) southeast of Medellin, Colombia. The conspicuous dark spot is a lake at the bottom of an approximately 3-kilometer-wide (1.9-mile) volcanic collapse depression or caldera. A cone-shaped peak on the bottom left (northeast rim) of the caldera appears to have been the source for a flow of material into the caldera. This is the northern-most known volcano in South America and because of its youthful appearance, should be considered dormant rather than extinct. The volcano's existence confirms a fracture zone proposed in 1985 as the northern boundary of volcanism in the Andes. The SIR-C/X-SAR image reveals another, older caldera further south in Colombia, along another proposed fracture zone. Although relatively conspicuous, these volcanoes have escaped widespread recognition because of frequent cloud cover that hinders remote sensing imaging in visible wavelengths. Four separate volcanoes in the Northern Andes nations ofColombia and Ecuador have been active during the last 10 years, killing more than 25,000 people, including scientists who were monitoring the volcanic activity. Detection and monitoring of volcanoes from space provides a safe way to investigate volcanism. The recognition of previously unknown volcanoes is important for hazard evaluations because a number of major eruptions this century have occurred at mountains that were not previously recognized as volcanoes. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of

  7. Radar Observation of Insects - Mosquitoes

    NASA Technical Reports Server (NTRS)

    Frost, E.; Downing, J.

    1979-01-01

    Tests were conducted at several sites over the coastal lowlands of New Jersey and over a region of high plains and low mountains in Oklahoma. In one area, a salt marsh in New Jersey, extensive ground tests were combined with laboratory data on expected insect backscatter to arrive at an extremely convincing model of the insect origin of most Dot Angels. A great deal of insight was studied from radar on the buildup and dispersal of insect swarms, since radar can follow where other means of trapping and observation cannot. Data on large-scale behavior as a function of wind and topography are presented. Displayed techniques which show individual or small swarm motion within some larger cloud or mass, or which can show the overall motion over great distances were developed. The influence of wind and terrain on insect motion and dispersal is determined from radar data.

  8. Scanning ARM Cloud Radar Handbook

    SciTech Connect

    Widener, K; Bharadwaj, N; Johnson, K

    2012-06-18

    The scanning ARM cloud radar (SACR) is a polarimetric Doppler radar consisting of three different radar designs based on operating frequency. These are designated as follows: (1) X-band SACR (X-SACR); (2) Ka-band SACR (Ka-SACR); and (3) W-band SACR (W-SACR). There are two SACRs on a single pedestal at each site where SACRs are deployed. The selection of the operating frequencies at each deployed site is predominantly determined by atmospheric attenuation at the site. Because RF attenuation increases with atmospheric water vapor content, ARM's Tropical Western Pacific (TWP) sites use the X-/Ka-band frequency pair. The Southern Great Plains (SGP) and North Slope of Alaska (NSA) sites field the Ka-/W-band frequency pair. One ARM Mobile Facility (AMF1) has a Ka/W-SACR and the other (AMF2) has a X/Ka-SACR.

  9. Data acquisition system for Doppler radar vital-sign monitor.

    PubMed

    Vergara, Alexander M; Lubecke, Victor M

    2007-01-01

    Automatic gain control (AGC) units increase the dynamic range of a system to compensate for the limited dynamic range of analog to digital converters. This problem is compounded in wireless systems in which large changes in signal strength are effects of a changing environment. These issues are evident in the direct-conversion Doppler radar vital-sign monitor. Utilizing microwave radar signals reflecting off a human subject, a two-channel quadrature receiver can detect periodic movement resulting from cardio-pulmonary activity. The quadrature signal is analyzed using an arctangent demodulation that extracts vital phase information. A data acquisition (DAQ) system is proposed to deal with issues inherent in arctangent demodulation of a quadrature radar signal.

  10. Radar observations of near-Earth asteroids from Arecibo Observatory

    NASA Astrophysics Data System (ADS)

    Rivera-Valentin, Edgard G.; Taylor, Patrick A.; Rodriguez-Ford, Linda A.; Zambrano Marin, Luisa Fernanda; Virkki, Anne; Aponte Hernandez, Betzaida

    2016-10-01

    The Arecibo S-Band (2.38 GHz, 12.6 cm, 1 MW) planetary radar system at the 305-m William E. Gordon Telescope in Arecibo, Puerto Rico is the most active and most sensitive planetary radar facility in the world. Since October 2015, we have detected 56 near-Earth asteroids, of which 17 are classified as potentially hazardous to Earth and 22 are compliant with the Near-Earth Object Human Space Flight Accessible Target Study (NHATS) as possible future robotic- or human-mission destinations. We will present a sampling of the asteroid zoo observed by the Arecibo radar since the 2015 DPS meeting. This includes press-noted asteroids 2015 TB145, the so-called "Great Pumpkin", and 2003 SD220, the so-called "Christmas Eve asteroid".

  11. probing the atmosphere with high power, high resolution radars

    NASA Technical Reports Server (NTRS)

    Hardy, K. R.; Katz, I.

    1969-01-01

    Observations of radar echoes from the clear atmosphere are presented and the scattering mechanisms responsible for the two basic types of clear-air echoes are discussed. The commonly observed dot echo originates from a point in space and usually shows little variation in echo intensity over periods of about 0.1 second. The second type of clear-air radar echo appears diffuse in space, and signal intensities vary considerably over periods of less than 0.1 second. The echoes often occur in thin horizontal layers or as boundaries of convective activity; these are characterized by sharp gradients of refractive index. Some features of clear-air atmospheric structures as observed with radar are presented. These structures include thin stable inversions, convective thermals, Benard convection cells, breaking gravity waves, and high tropospheric layers which are sufficiently turbulent to affect aircraft.

  12. Radar operation in a hostile electromagnetic environment

    SciTech Connect

    Doerry, Armin Walter

    2014-03-01

    Radar ISR does not always involve cooperative or even friendly targets. An adversary has numerous techniques available to him to counter the effectiveness of a radar ISR sensor. These generally fall under the banner of jamming, spoofing, or otherwise interfering with the EM signals required by the radar sensor. Consequently mitigation techniques are prudent to retain efficacy of the radar sensor. We discuss in general terms a number of mitigation techniques.

  13. Goldstone solar system radar signal processing

    NASA Technical Reports Server (NTRS)

    Jurgens, R. F.; Satorius, E.; Sanchez, O.

    1992-01-01

    A performance analysis of the planetary radar data acquisition system is presented. These results extend previous computer simulation analysis and are facilitated by the development of a simple analytical model that predicts radar system performance over a wide range of operational parameters. The results of this study are useful to both the radar systems designer and the science investigator in establishing operational radar data acquisition parameters which result in the best systems performance for a given set of input conditions.

  14. Goldstone solar system radar signal processing

    NASA Technical Reports Server (NTRS)

    Jurgens, R.; Satorius, E.; Sanchez, O.

    1992-01-01

    A performance analysis of the planetary radar data acquisition system is presented. These results extend previous computer simulation analysis and are facilitated by the development of a simple analytical model that predicts radar system performance over a wide range of operational parameters. The results of this study are useful to both the radar system designer and the science investigator in establishing operational radar data acquisition parameters which result in the best systems performance for a given set of input conditions.

  15. An MSK Waveform for Radar Applications

    NASA Technical Reports Server (NTRS)

    Quirk, Kevin J.; Srinivasan, Meera

    2009-01-01

    We introduce a minimum shift keying (MSK) waveform developed for use in radar applications. This waveform is characterized in terms of its spectrum, autocorrelation, and ambiguity function, and is compared with the conventionally used bi-phase coded (BPC) radar signal. It is shown that the MSK waveform has several advantages when compared with the BPC waveform, and is a better candidate for deep-space radar imaging systems such as NASA's Goldstone Solar System Radar.

  16. SAR Ambiguity Study for the Cassini Radar

    NASA Technical Reports Server (NTRS)

    Hensley, Scott; Im, Eastwood; Johnson, William T. K.

    1993-01-01

    The Cassini Radar's synthetic aperture radar (SAR) ambiguity analysis is unique with respect to other spaceborne SAR ambiguity analyses owing to the non-orbiting spacecraft trajectory, asymmetric antenna pattern, and burst mode of data collection. By properly varying the pointing, burst mode timing, and radar parameters along the trajectory this study shows that the signal-to-ambiguity ratio of better than 15 dB can be achieved for all images obtained by the Cassini Radar.

  17. FMCW Radar Jamming Techniques and Analysis

    DTIC Science & Technology

    2013-09-01

    discussed. 14. SUBJECT TERMS FMCW Radar , LPI , Jamming, Electronic Warfare 15. NUMBER OF PAGES 103 16. PRICE CODE 17. SECURITY CLASSIFICATION...Among the many variations of LPI radar systems, Frequency-Modulated Continuous Wave ( FMCW ) radar has not only the ability to avoid detection, but... LPI radars and possible electronic protection (EP) mechanisms that may be implemented in the FMCW emitter. The research questions can be summarized

  18. Possible Effects on the Stability of the West Antarctic Ice Sheet (WAIS) and Associated Sea-level Rise From Active-Recent Subglacial Volcanism Interpreted from Aeromagnetic and Radar Ice-sounding Observations

    NASA Astrophysics Data System (ADS)

    Behrendt, J. C.

    2009-12-01

    Aeromagnetic profiles (>10,000 km) acquired in the early 1960s over the West Antarctic Ice Sheet (WAIS) combined with coincident aeromagnetic and radar ice sounding in 1978-79 indicated numerous high-amplitude, shallow-source, magnetic anomalies over a very extensive area of the volcanically active West Antarctic rift system interpreted as caused by subglacial volcanic rocks. These early aerogeophysical surveys defined this area as >500,000 km2. Five-kilometer spaced coincident aeromagnetic and radar ice sounding surveys since 1990 provide three dimensional characterization of the magnetic field and bed topography beneath the ice sheet. These 5-50-km width, semicircular magnetic anomalies range from 100->1000 nT as observed ~1 km over the 2-3 km thick ice. Behrendt et al, (2005, 2008) interpreted these anomalies as indicating >1000 "volcanic centers". requiring high remanent normal (and at least 10% reversed) magnetizations in the present field direction. These data have shown that >80% of the anomaly sources at the bed of the WAIS, have been modified by the moving ice into which they were injected, requiring a younger age than the WAIS (about 25 Ma). Behrendt et al., (1994; 2007) conservatively estimated >1 x 106 km3 volume of volcanic sources to account for the area of the "volcanic center" anomalies. Although exposed volcanoes surrounding the WAIS extend in age to ~34 m.y., Mt Erebus, (<1 Ma) Mt. Melbourne, (<0.26 Ma), and Mt. Takahae (<0.1 Ma) are examples of exposed active volcanoes in the WAIS area. However, the great volume of volcanic centers is buried beneath the WAIS. If only a very small percentage of these >1000 volcanic, magnetic-anomaly sources are active today, or in the recent past, in the drainage area of the WAIS, subglacial volcanism may still have a significant effect on the dynamics of the WAIS. Interpreted active subglacial volcanism is revealed by aerogeophysical data reported by Blankenship et al., (1993, Mt. Casertz), and Corr and Vaughan

  19. Portable receiver for radar detection

    DOEpatents

    Lopes, Christopher D.; Kotter, Dale K.

    2008-10-14

    Various embodiments are described relating to a portable antenna-equipped device for multi-band radar detection. The detection device includes a plurality of antennas on a flexible substrate, a detection-and-control circuit, an indicator and a power source. The antenna may include one or more planar lithographic antennas that may be fabricated on a thin-film substrate. Each antenna may be tuned to a different selection frequency or band. The antennas may include a bolometer for radar detection. Each antenna may include a frequency selective surface for tuning to the selection frequency.

  20. Synthetic Aperture Radar Oceanographic Investigations.

    DTIC Science & Technology

    1987-03-01

    Shuchman, P.G. Teleki, S.V. Hsiao, O.H. Shemdin , and W.E. Brown, Synthetic Aperture Radar Imaging of Ocean Waves : Comparison with Wave Measurements, J... Shemdin , Synthetic Aperture Radar Imaging of Ocean Waves during the Marineland Experiment, IEEE J. Oceanic Eg., OE-8, pp. 83-90, 1983. 12. R.A...If the surface reflectivity is assumed to be spatially un- section. are computed from the wave height spectrum as correlated, i.e. follows . (x. Y. t

  1. 46 CFR 130.310 - Radar.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse....

  2. 46 CFR 15.815 - Radar observers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Radar observers. 15.815 Section 15.815 Shipping COAST... Computations § 15.815 Radar observers. (a) Each person in the required complement of deck officers, including the master, on inspected vessels of 300 gross tons or over which are radar equipped, shall hold...

  3. 46 CFR 167.40-40 - Radar.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Radar. 167.40-40 Section 167.40-40 Shipping COAST GUARD... Requirements § 167.40-40 Radar. All mechanically propelled vessels of 1,600 gross tons and over in ocean or coastwise service must be fitted with a marine radar system for surface navigation. Facilities for...

  4. 46 CFR 169.726 - Radar reflector.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Radar reflector. 169.726 Section 169.726 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.726 Radar reflector. Each nonmetallic vessel less than 90 feet in length must exhibit a radar reflector of suitable size and design while underway. Markings...

  5. 46 CFR 169.726 - Radar reflector.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Radar reflector. 169.726 Section 169.726 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.726 Radar reflector. Each nonmetallic vessel less than 90 feet in length must exhibit a radar reflector of suitable size and design while underway. Markings...

  6. 46 CFR 130.310 - Radar.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse....

  7. 46 CFR 15.815 - Radar observers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Radar observers. 15.815 Section 15.815 Shipping COAST... Computations § 15.815 Radar observers. (a) Each person in the required complement of deck officers, including the master, on inspected vessels of 300 gross tons or over which are radar equipped, shall hold...

  8. 46 CFR 167.40-40 - Radar.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Radar. 167.40-40 Section 167.40-40 Shipping COAST GUARD... Requirements § 167.40-40 Radar. All mechanically propelled vessels of 1,600 gross tons and over in ocean or coastwise service must be fitted with a marine radar system for surface navigation. Facilities for...

  9. 46 CFR 167.40-40 - Radar.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Radar. 167.40-40 Section 167.40-40 Shipping COAST GUARD... Requirements § 167.40-40 Radar. All mechanically propelled vessels of 1,600 gross tons and over in ocean or coastwise service must be fitted with a marine radar system for surface navigation. Facilities for...

  10. 46 CFR 11.480 - Radar observer.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Radar observer. 11.480 Section 11.480 Shipping COAST... ENDORSEMENTS Professional Requirements for National Deck Officer Endorsements § 11.480 Radar observer. (a) This section contains the requirements that an applicant must meet to qualify as a radar observer. (b) If...

  11. 46 CFR 169.726 - Radar reflector.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Radar reflector. 169.726 Section 169.726 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.726 Radar reflector. Each nonmetallic vessel less than 90 feet in length must exhibit a radar reflector of suitable size and design while underway. Markings...

  12. 46 CFR 169.726 - Radar reflector.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Radar reflector. 169.726 Section 169.726 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.726 Radar reflector. Each nonmetallic vessel less than 90 feet in length must exhibit a radar reflector of suitable size and design while underway. Markings...

  13. 46 CFR 11.480 - Radar observer.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Radar observer. 11.480 Section 11.480 Shipping COAST... ENDORSEMENTS Professional Requirements for Deck Officers § 11.480 Radar observer. (a) This section contains the requirements that an applicant must meet to qualify as a radar observer. (Part 15 of this chapter specifies...

  14. 46 CFR 15.815 - Radar observers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Radar observers. 15.815 Section 15.815 Shipping COAST... Computations § 15.815 Radar observers. (a) Each person in the required complement of deck officers, including the master, on inspected vessels of 300 GRT or over which are radar equipped, must hold an...

  15. 46 CFR 15.815 - Radar observers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Radar observers. 15.815 Section 15.815 Shipping COAST... Computations § 15.815 Radar observers. (a) Each person in the required complement of deck officers, including the master, on inspected vessels of 300 gross tons or over which are radar equipped, shall hold...

  16. 46 CFR 130.310 - Radar.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse....

  17. 46 CFR 130.310 - Radar.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse....

  18. 46 CFR 167.40-40 - Radar.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Radar. 167.40-40 Section 167.40-40 Shipping COAST GUARD... Requirements § 167.40-40 Radar. All mechanically propelled vessels of 1,600 gross tons and over in ocean or coastwise service must be fitted with a marine radar system for surface navigation. Facilities for...

  19. 46 CFR 167.40-40 - Radar.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Radar. 167.40-40 Section 167.40-40 Shipping COAST GUARD... Requirements § 167.40-40 Radar. All mechanically propelled vessels of 1,600 gross tons and over in ocean or coastwise service must be fitted with a marine radar system for surface navigation. Facilities for...

  20. 46 CFR 15.815 - Radar observers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Radar observers. 15.815 Section 15.815 Shipping COAST... Computations § 15.815 Radar observers. (a) Each person in the required complement of deck officers, including the master, on inspected vessels of 300 gross tons or over which are radar equipped, shall hold...

  1. 46 CFR 130.310 - Radar.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse....

  2. 46 CFR 169.726 - Radar reflector.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Radar reflector. 169.726 Section 169.726 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.726 Radar reflector. Each nonmetallic vessel less than 90 feet in length must exhibit a radar reflector of suitable size and design while underway. Markings...

  3. 46 CFR 184.404 - Radars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface...

  4. 46 CFR 184.404 - Radars.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface...

  5. Comparison of radar data versus rainfall data.

    PubMed

    Espinosa, B; Hromadka, T V; Perez, R

    2015-01-01

    Doppler radar data are increasingly used in rainfall-runoff synthesis studies, perhaps due to radar data availability, among other factors. However, the veracity of the radar data are often a topic of concern. In this paper, three Doppler radar outcomes developed by the United States National Weather Service at three radar sites are examined and compared to actual rain gage data for two separate severe storm events in order to assess accuracy in the published radar estimates of rainfall. Because the subject storms were very intense rainfall events lasting approximately one hour in duration, direct comparisons between the three radar gages themselves can be made, as well as a comparison to rain gage data at a rain gage location subjected to the same storm cells. It is shown that topographic interference with the radar outcomes can be a significant factor leading to differences between radar and rain gage readings, and that care is needed in calibrating radar outcomes using available rain gage data in order to interpolate rainfall estimates between rain gages using the spatial variation observed in the radar readings. The paper establishes and describes•the need for "ground-truthing" of radar data, and•possible errors due to topographic interference.

  6. 46 CFR 121.404 - Radars.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... has determined that a radar is not necessary due to the vessel's route and local weather conditions... 46 Shipping 4 2012-10-01 2012-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all...

  7. 46 CFR 184.404 - Radars.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface...

  8. 46 CFR 184.404 - Radars.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface...

  9. 46 CFR 121.404 - Radars.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... has determined that a radar is not necessary due to the vessel's route and local weather conditions... 46 Shipping 4 2014-10-01 2014-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all...

  10. 46 CFR 121.404 - Radars.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... has determined that a radar is not necessary due to the vessel's route and local weather conditions... 46 Shipping 4 2013-10-01 2013-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all...

  11. 46 CFR 121.404 - Radars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... has determined that a radar is not necessary due to the vessel's route and local weather conditions... 46 Shipping 4 2010-10-01 2010-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all...

  12. 46 CFR 121.404 - Radars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... has determined that a radar is not necessary due to the vessel's route and local weather conditions... 46 Shipping 4 2011-10-01 2011-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all...

  13. 46 CFR 184.404 - Radars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface...

  14. Radar geomorphology of coastal and wetland environments

    NASA Technical Reports Server (NTRS)

    Lewis, A. J.; Macdonald, H. C.

    1973-01-01

    Details regarding the collection of radar imagery over the past ten years are considered together with the geomorphic, geologic, and hydrologic data which have been extracted from radar imagery. Recent investigations were conducted of the Louisiana swamp marsh and the Oregon coast. It was found that radar imagery is a useful tool to the scientist involved in wetland research.

  15. Asteroid Radar V18.0

    NASA Astrophysics Data System (ADS)

    Neese, C.; Benner, L. A. M.; Ostro, S. J.

    2012-06-01

    This data set is intended to include all published groundbased asteroid radar detections. The file is based on the collection of asteroid radar detections established by Steven J. Ostro and currently maintained by Lance A.M. Benner. The file includes disc-integrated radar properties extracted from the published papers.

  16. Efficient Ways to Learn Weather Radar Polarimetry

    ERIC Educational Resources Information Center

    Cao, Qing; Yeary, M. B.; Zhang, Guifu

    2012-01-01

    The U.S. weather radar network is currently being upgraded with dual-polarization capability. Weather radar polarimetry is an interdisciplinary area of engineering and meteorology. This paper presents efficient ways to learn weather radar polarimetry through several basic and practical topics. These topics include: 1) hydrometeor scattering model…

  17. Tracking radar studies of bird migration

    NASA Technical Reports Server (NTRS)

    Williams, T. C.; Williams, J. M.; Teal, J. M.; Kanwisher, J. W.

    1972-01-01

    The application of tracking radar for determining the flight paths of migratory birds is discussed. The effects produced by various meteorological parameters are described. Samples of radar scope presentations obtained during tracking studies are presented. The characteristics of the radars and their limitations are examined.

  18. Compressive Sensing for Radar and Radar Sensor Networks

    DTIC Science & Technology

    2013-12-02

    27] Hong-Sam Le, Qilian Liang, “Joint Multi-target Identification and Classification in Cognitive Radar Sensor Networks,” International Journal of Wireless Information Networks , vol...Networks," International Journal of Wireless Information Networks , vol. 18, no. 2, pp. 100-107, 2011. 8. Sukhvinder Singh, Qilian Liang, Dechang

  19. Space Radar Image of Karisoke & Virunga Volcanoes

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false-color composite of Central Africa, showing the Virunga volcano chain along the borders of Rwanda, Zaire and Uganda. This area is home to the endangered mountain gorillas. The image was acquired on October 3, 1994, on orbit 58 of the space shuttle Endeavour by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR). In this image red is the L-band (horizontally transmitted, vertically received) polarization; green is the C-band (horizontally transmitted and received) polarization; and blue is the C-band (horizontally transmitted and received) polarization. The area is centered at about 2.4 degrees south latitude and 30.8 degrees east longitude. The image covers an area 56 kilometers by 70 kilometers (35 miles by 43 miles). The dark area at the top of the image is Lake Kivu, which forms the border between Zaire (to the right) and Rwanda (to the left). In the center of the image is the steep cone of Nyiragongo volcano, rising 3,465 meters (11,369 feet) high, with its central crater now occupied by a lava lake. To the left are three volcanoes, Mount Karisimbi, rising 4,500 meters (14,800 feet) high; Mount Sabinyo, rising 3,600 meters (12,000 feet) high; and Mount Muhavura, rising 4,100 meters (13,500 feet) high. To their right is Nyamuragira volcano, which is 3,053 meters (10,017 feet) tall, with radiating lava flows dating from the 1950s to the late 1980s. These active volcanoes constitute a hazard to the towns of Goma, Zaire and the nearby Rwandan refugee camps, located on the shore of Lake Kivu at the top left. This radar image highlights subtle differences in the vegetation of the region. The green patch to the center left of the image in the foothills of Karisimbi is a bamboo forest where the mountain gorillas live. The vegetation types in this area are an important factor in the habitat of mountain gorillas. Researchers at Rutgers University in New Jersey and the Dian Fossey Gorilla Fund in London will use this data to produce

  20. Space Radar Image of Taal Volcano, Philippines

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of Taal volcano, near Manila on the island of Luzon in the Philippines. The black area in the center is Taal Lake, which nearly fills the 30-kilometer-diameter (18-mile) caldera. The caldera rim consists of deeply eroded hills and cliffs. The large island in Taal Lake, which itself contains a crater lake, is known as Volcano Island. The bright yellow patch on the southwest side of the island marks the site of an explosion crater that formed during a deadly eruption of Taal in 1965. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 78th orbit on October 5, 1994. The image shows an area approximately 56 kilometers by 112 kilometers (34 miles by 68 miles) that is centered at 14.0 degrees north latitude and 121.0 degrees east longitude. North is toward the upper right of the image. The colors in this image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted and vertically received); blue represents the C-band (horizontally transmitted and vertically received). Since 1572, Taal has erupted at least 34 times. Since early 1991, the volcano has been restless, with swarms of earthquakes, new steaming areas, ground fracturing, and increases in water temperature of the lake. Volcanologists and other local authorities are carefully monitoring Taal to understand if the current activity may foretell an eruption. Taal is one of 15 'Decade Volcanoes' that have been identified by the volcanology community as presenting large potential hazards to population centers. The bright area in the upper right of the image is the densely populated city of Manila, only 50 kilometers (30 miles) north of the central crater. Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth