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Sample records for superdarn hokkaido radar

  1. SuperDARN scalar radar equations

    CERN Document Server

    Berngardt, O I; Potekhin, A P

    2016-01-01

    The quadratic scalar radar equations are obtained for SuperDARN radars that are suitable for the analysis and interpretation of experimental data. The paper is based on a unified approach to the obtaining radar equations for the monostatic and bistatic sounding with use of hamiltonian optics and ray representation of scalar Green's function and without taking into account the polarization effects. The radar equation obtained is the sum of several terms corresponding to the propagation and scattering over the different kinds of trajectories, depending on their smoothness and the possibility of reflection from the ionosphere. It is shown that the monostatic sounding in the media with significant refraction, unlike the case of refraction-free media, should be analyzed as a combination of monostatic and bistatic scattering. This leads to strong dependence of scattering amplitude on background ionospheric density due to focusing mechanism and appearance of new (bistatic) areas of effective scattering with signific...

  2. Evidence of Polar Mesosphere Summer Echoes Observed by SuperDARN SANAE HF Radar in Antarctica

    OpenAIRE

    Olakunle Ogunjobi; Venkataraman Sivakumar; Judy Ann Elizabeth Stephenson; and William Tafon Sivla

    2015-01-01

    We report on the polar mesosphere summer echoes (PMSE) occurrence probability over SANAE (South African National Antarctic Expedition) IV, for the first time. A matching coincidence method is described and implemented for PMSE extraction from SuperDARN (Super Dual Auroral Radar Network) HF radar. Several SuperDARN-PMSE characteristics are studied during the summer period from years 2005 - 2007. The seasonal and interannual SuperDARN-PMSE variations in relation to the mesospheric neutral winds...

  3. Joint observations of a traveling ionospheric disturbance with the Paratunka OMTI camera and the Hokkaido HF radar

    Directory of Open Access Journals (Sweden)

    A. Koustov

    2009-06-01

    Full Text Available On 10 September 2007 between 10:00 and 14:00 UT, the OMTI all-sky imager at Paratunka (Kamchatka, Russia, GLAT~52° observed the onset and south-western progression of a localized depletion region in the airglow intensity. The perturbation, while being stretched in the NW-SE direction, crossed the entire field of view of the camera. During the event, the Hokkaido SuperDARN HF radar was monitoring echoes in the Paratunka longitudinal sector. It was detecting a localized band of ground scatter echoes progressing equatorward synchronously with the motion of the optical perturbation. It is suggested that both features resulted from the onset and south-western progression of a localized region with enhanced electric field that influenced the distribution of the plasma density in the ionosphere. Modeling of the HF ground scatter dynamics based on numerical ray tracing demonstrated qualitative consistency with the observations.

  4. First observations of polar mesosphere summer echoes by SuperDARN Zhongshan radar

    Science.gov (United States)

    Liu, E. X.; Hu, H. Q.; Hosokawa, K.; Liu, R. Y.; Wu, Z. S.; Xing, Z. Y.

    2013-11-01

    We report the first observations of PMSE by SuperDARN Zhongshan radar in Antarctica and present a statistical analysis of PMSE from 2010 to 2012. The seasonal variations of occurrence are consistent with those before, with an obvious enhancement at the beginning of summer and a maximum several days after summer solstice. The special features of diurnal variations were observed because of high geomagnetic latitude of Zhongshan Station, which is that the maximum is near local midnight and the secondary maximum appears 1-2 h after the local noon. The results proved that the auroral particle precipitation plays a fairly important role in the PMSE occurrence.

  5. PMSE long term observations using SuperDARN SANAE HF radar measurements

    Directory of Open Access Journals (Sweden)

    Olakunle Ogunjobi

    2017-01-01

    Full Text Available It is known that the presence of nanometre-scale ice particles and neutral air turbulence in the Polar summer mesosphere modify the D-region plasma, resulting in strong backscatter. These strong backscatters are referred to as Polar Mesosphere Summer Echoes (PMSE. Although studies on PMSE have been ongoing for over three decades, aspects revealed by various instruments are still the subject of discussion. As a sequel to the paper by Ogunjobi et al. (2015, we report on the long term trends and variations in PMSE occurrence probability from Super Dual Auroral Radar Network (SuperDARN high frequency (HF radar measurements over the South African National Antarctic Expedition IV (SANAE IV. In this current paper, a simple multiple-filter technique is employed to obtain the occurrence probability rate for SuperDARN-PMSE during the summer periods for the years 1998 - 2007. The SuperDARN-PMSE occurrence probability rate in relation to geomagnetic activity is examined. The mesospheric neutral winds and temperature trends during these periods, are further studied and presented in this paper. Both the monthly and diurnal variations in occurrence are consistent with previous reports, confirming the presence of PMSE from SuperDARN SANAE IV radar measurements and the influence of pole to pole mesospheric transport circulation. The special mesospheric mean flow observed prior to the year 2002 is ascribed to the influence of solar activity. The SuperDARN-PMSE occurrence probability peaks with lowered geomagnetic activity. These present results support the hypothesis that the particle precipitation also plays an important role in SuperDARN-PMSE occurrence.

  6. Comparison of D-region Doppler drift winds measured by the SuperDARN Finland HF radar over an annual cycle using the Kiruna VHF meteor radar

    Directory of Open Access Journals (Sweden)

    N. F. Arnold

    Full Text Available The SuperDARN chain of oblique HF radars has provided an opportunity to generate a unique climatology of horizontal winds near the mesopause at a number of high latitude locations, via the Doppler shifted echoes from sources of ionisation in the D-region. Ablating meteor trails form the bulk of these targets, but other phenomena also contribute to the observations. Due to the poor vertical resolution of the radars, care must be taken to reduce possible biases from sporadic-E layers and Polar Mesospheric Summer echoes that can affect the effective altitude of the geophysical parameters being observed. Second, there is strong theoretical and observational evidence to suggest that the radars are picking up echoes from the backward looking direction that will tend to reduce the measured wind strengths. The effect is strongly frequency dependent, resulting in a 20% reduction at 12 MHz and a 50% reduction at 10 MHz. A comparison of the climatologies observed by the Super-DARN Finland radar between September 1999 and September 2000 and that obtained from the adjacent VHF meteor radar located at Kiruna is also presented. The agreement between the two instruments was very good. Extending the analysis to the SuperDARN Iceland East radar indicated that the principles outlined above could be applied successfully to the rest of the SuperDARN network.

    Key words. Ionosphere (ionosphere-atmosphere interactions; instruments and techniques – Meteorology and atmospheric dynamics (waves and tides

  7. A long-term comparison of wind and tide measurements in the upper mesosphere recorded with an imaging Doppler interferometer and SuperDARN radar at Halley, Antarctica

    Directory of Open Access Journals (Sweden)

    R. E. Hibbins

    2008-03-01

    Full Text Available Data from a near co-located imaging Doppler interferometer (IDI and SuperDARN radar recorded since 1996 have been analysed in a consistent manner to compare the derived mean winds and tides in the upper mesosphere. By comparing only days when both techniques were recording good quality meridional wind data it is shown that the SuperDARN radar winds and tides correlate best with the IDI height bin 90–95 km. On timescales of one hour the winds derived from the IDI have a much greater associated variance and correlate poorly with the SuperDARN winds. Regression analysis reveals that the observed SuperDARN daily mean meridional wind strength is approximately 65% that recorded by the IDI, in good quantitative agreement with previous studies which have shown contamination to SuperDARN derived winds due to the significant back lobe of the radar radiation pattern. Climatologically the two techniques observe similar monthly mean winds with the SuperDARN meridional winds suppressed compared to the IDI which tends to record winds more poleward than those derived by the SuperDARN radar during the summer months, and to be slightly more equatorward during the winter. The 12-h tidal amplitude and phase derived from both techniques are in good agreement, whereas the 24-h tides are seen much more strongly in the SuperDARN radar, especially in wintertime, with poor phase agreement. Long term comparison of the two techniques reveals a tendency for the IDI meridional winds to be more poleward during solar maximum especially during summer time; an effect which is not reproduced in the meridional winds derived from the SuperDARN radar. These results are discussed in the context of previous studies to independently determine the veracity of each technique, and to highlight the circumstances where data derived from these two techniques can be used to draw reliable conclusions from comparative studies based on geographically distributed pairs of instruments.

  8. Sources and Characteristics of Medium Scale Traveling Ionospheric Disturbances Observed by SuperDARN Radars in the North American Sector

    Science.gov (United States)

    Frissell, N. A.; Baker, J. B.; Ruohoniemi, J. M.; Greenwald, R. A.; Gerrard, A. J.; Miller, E. S.; West, M. L.

    2015-12-01

    Medium Scale Traveling Ionospheric Disturbances (MSTIDs) are wave-like perturbations of the F-region ionosphere with horizontal wavelengths on the order of several hundred kilometers, and periods between 15 - 60 min. In SuperDARN radar data, MSTID signatures are manifested as quasi-periodic enhancements of ground backscatter (i.e. skip focusing) which propagate through the radar field-of-view. At high latitudes, SuperDARN observations of MSTIDs have generally been attributed to atmospheric gravity waves (AGWs) launched by auroral sources (e.g. Joule heating). However, recent studies with newer mid-latitude radars have shown MSTIDs are routinely observed in the subauroral ionosphere as well. To develop a more complete picture of MSTID activity, we have surveyed observations from four high latitude and six mid latitude SuperDARN radars located in the North American sector collected between 2011 and 2015 during the months of November to May. Consistent with previous SuperDARN MSTID studies, all radars observed MSTIDs with horizontal wavelengths between ~250 - 500 km and horizontal velocities between ~100 - 250 m/s. The majority of the MSTIDs were observed to propagate in a predominantly southward direction, with bearings ranging from ~135 ̊ - 250 ̊ geographic azimuth. This is highly suggestive of high latitude auroral sources; however, no apparent correlation with geomagnetic or space weather activity could be identified. Rather, comparison of the SuperDARN MSTID time-series data with northern hemisphere geopotential data from the European Center for Medium Range Weather Forecasting (ECMWF) operational model reveals a strong correlation of MSTID activity with dynamics in the polar vortex structure on two primary time scales. First, a seasonal effect manifests as enhanced MSTID activity from November through January, followed by a depressed period from February to May. This appears to correspond with the seasonal development and later decay of the polar vortex. A

  9. On determining the noon polar cap boundary from SuperDARN HF radar backscatter characteristics

    Directory of Open Access Journals (Sweden)

    M. Pinnock

    Full Text Available Previous work has shown that ionospheric HF radar backscatter in the noon sector can be used to locate the footprint of the magnetospheric cusp particle precipitation. This has enabled the radar data to be used as a proxy for the location of the polar cap boundary, and hence measure the flow of plasma across it to derive the reconnection electric field in the ionosphere. This work used only single radar data sets with a field of view limited to ~2 h of local time. In this case study using four of the SuperDARN radars, we examine the boundary determined over 6 h of magnetic local time around the noon sector and its relationship to the convection pattern. The variation with longitude of the latitude of the radar scatter with cusp characteristics shows a bay-like feature. It is shown that this feature is shaped by the variation with longitude of the poleward flow component of the ionospheric plasma and may be understood in terms of cusp ion time-of-flight effects. Using this interpretation, we derive the time-of-flight of the cusp ions and find that it is consistent with approximately 1 keV ions injected from a subsolar reconnection site. A method for deriving a more accurate estimate of the location of the open-closed field line boundary from HF radar data is described.

    Key words: Ionosphere (ionosphere–magnetosphere interactions; plasma convection · Magnetospheric physics (magnetopause · cusp · and boundary layers

  10. Mapping ionospheric backscatter measured by the SuperDARN HF radars – Part 1: A new empirical virtual height model

    Directory of Open Access Journals (Sweden)

    T. K. Yeoman

    2008-05-01

    Full Text Available Accurately mapping the location of ionospheric backscatter targets (density irregularities identified by the Super Dual Auroral Radar Network (SuperDARN HF radars can be a major problem, particularly at far ranges for which the radio propagation paths are longer and more uncertain. Assessing and increasing the accuracy of the mapping of scattering locations is crucial for the measurement of two-dimensional velocity structures on the small and meso-scale, for which overlapping velocity measurements from two radars need to be combined, and for studies in which SuperDARN data are used in conjunction with measurements from other instruments. The co-ordinates of scattering locations are presently estimated using a combination of the measured range and a model virtual height, assuming a straight line virtual propagation path. By studying elevation angle of arrival information of backscatterred signals from 5 years of data (1997–2001 from the Saskatoon SuperDARN radar we have determined the actual distribution of the backscatter target locations in range-virtual height space. This has allowed the derivation of a new empirical virtual height model that allows for a more accurate mapping of the locations of backscatter targets.

  11. Evidence of Polar Mesosphere Summer Echoes Observed by SuperDARN SANAE HF Radar in Antarctica

    Directory of Open Access Journals (Sweden)

    Olakunle Ogunjobi

    2015-01-01

    Full Text Available We report on the polar mesosphere summer echoes (PMSE occurrence probability over SANAE (South African National Antarctic Expedition IV, for the first time. A matching coincidence method is described and implemented for PMSE extraction from SuperDARN (Super Dual Auroral Radar Network HF radar. Several SuperDARN-PMSE characteristics are studied during the summer period from years 2005 - 2007. The seasonal and interannual SuperDARN-PMSE variations in relation to the mesospheric neutral winds are studied and presented in this paper. The occurrence probability of SuperDARN-PMSE on the day-to-day scale show, predominantly, diurnal variation, with a broader peak between 12 - 14 LT and distinct minimum of 22 LT. The SuperDARN-PMSE occurrence probability rate is high in the summer solstice. Seasonal variations show a connection between the SuperDARN-PMSE occurrence probability rate and mesospheric temperature from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry. The seasonal trend for both meridional and zonal winds is very stable year-to-year. Analysis of the neutral wind variations indicates the importance of pole-to-pole circulations in SuperDARN-PMSE generation.

  12. PCN magnetic index and average convection velocity in the polar cap inferred from SuperDARN radar measurements

    Science.gov (United States)

    Fiori, R. A. D.; Koustov, A. V.; Boteler, D.; Makarevich, R. A.

    2009-07-01

    The relationship between the polar cap north (PCN) magnetic index and the average convection velocity of the plasma flow across the polar cap is investigated using data from both the Rankin Inlet (RKN) polar cap Super Dual Auroral Radar Network (SuperDARN) radar and the entire SuperDARN network. Correlation between the PCN index and the average velocity, determined from the median RKN line of sight (LOS) velocity, maximizes near magnetic noon and midnight when the radar field of view is roughly aligned with the noon-midnight meridian. For observations between 1000 and 1100 MLT, a roughly linear increase of the average velocity was found for a PCN index between 0 and 2, but the rate of increase is ˜2 times faster than in previous publications in which the average velocity was estimated from DMSP ion drift measurements. Comparisons between the PCN index with the cross-polar cap velocity estimated from (1) SuperDARN convection maps and (2) median RKN LOS velocities show similar trends. Both the average cross-polar cap velocity (estimated by two methods) and the cross-polar cap potential show a tendency for saturation at PCN > 2. No significant seasonal change in the nature of the relationships was found.

  13. Studies of medium scale travelling ionospheric disturbances using TIGER SuperDARN radar sea echo observations

    Directory of Open Access Journals (Sweden)

    L.-S. He

    2004-12-01

    Full Text Available

    Seasonal and diurnal variations in the direction of propagation of medium-scale travelling ionospheric disturbances (MSTIDs have been investigated by analyzing sea echo returns detected by the TIGER SuperDARN radar located in Tasmania (43.4° S, 147.2° E geographic; –54.6°Λ. A strong dependency on local time was found, as well as significant seasonal variations. Generally, the propagation direction has a northward (i.e. equatorward component. In the early morning hours the direction of propagation is quite variable throughout the year. It then becomes predominantly northwest and changes to northeast around 09:00 LT. In late fall and winter it changes back to north/northwest around 15:00 LT. During the other seasons, northward propagation is very obvious near dawn and dusk, but no significant northward propagation is observed at noon.

    It is suggested that the variable propagation direction in the morning is related to irregular magnetic disturbances that occur at this local time. The changes in the MSTID propagation directions near dawn and dusk are generally consistent with changes in ionospheric electric fields occurring at these times and is consistent with dayside MSTIDs being generated by the Lorentz force.

    Key words. Ionosphere (ionospheric disturbances; wave propagation; ionospheric irregularities; signal processing

  14. SuperDARN CUTLASS Finland radar observations of high-latitude magnetic reconnections under northward interplanetary magnetic field (IMF) conditions

    Institute of Scientific and Technical Information of China (English)

    ZHANG QingHe; LIU RuiYuan; YANG HuiGen; HU HongQiao; ZHANG BeiChen; DUNLOP Malcolm; LESTER Mark; BOGDANOVA Yulia; WALSH Andrew

    2012-01-01

    A number of backscatter power enhancement events with “equatorward-moving radar auroral forms” in the high-latitude ionosphere were observed by SuperDARN CUTLASS Finland radar when the IMF was northward during 09:00 -10:00 UT on 26 March 2004.These events were also associated with sunward flow enhancements at each location in the Northern Hemisphere which were shown in ionospheric convections measured by the SuperDARN radars.These are typical features of high-latitude (lobe) magnetic reconnections.The durations of the velocity enhancements imply that the evolution time of the lobe reconnections is about 8-16 min from their origin at the reconnection site to their addition to the magnetotail lobe again.In additional,the Double Star TC-1 spacecraft was moving from magnetosheath into magnetosphere,and crossing the magnetopause near the subsolar region during this interval,and observed typical low-latitude magnetic reconnection signatures.This infers that the dayside high- and low-latitude reconnections may occur simultaneously.

  15. Investigation of Third Gyro-harmonic Heating at HAARP Using Stimulated Radio Emissions, the MUIR and SuperDARN Radars

    Science.gov (United States)

    Mahmoudian, Alireza; Bernhardt, Paul; Ruohoniemi, J. Michael; Isham, Brett; Watkins, Brenton; Scales, Wayne

    2016-07-01

    Use of high frequency (HF) heating experiments has been extended in recent years as a useful methodology for plasma physicists wishing to remotely study the properties and behavior of the ionosphere as well as nonlinear plasma processes. Our recent work using high latitude heating experiments has lead to several important discoveries that have enabled assessment of active geomagnetic conditions, determination of minor ion species and their densities, ion mass spectrometry, electron temperature measurements in the heating ionosphere, as well a deeper understanding of physical processes associated with electron acceleration and formation of field aligned irregularities. The data recorded during two campaigns at HAARP in 2011 and 2012 will be presented. Several diagnostic instruments have been used to detect HAARP heater-generated ionospheric irregularities and plasma waves. These diagnostics include an ionosonde, MUIR (Modular UHF Ionospheric Radar at 446 MHz), SuperDARN HF backscatter radar and ground-based SEE receivers. Variation of the wideband/ narrowband SEE features, SuperDARN echoes, and enhanced ion lines were studied with pump power variation, pump frequency stepping near 3fce as well as changing beam angle relative to the magnetic zenith. In particular, formation of field-aligned irregularities (FAIs) and upper hybrid (UH) waves through oscillating two-stream instability (OSTI) and resonance instability is studied. During heating, Narrowband SEE (NSEE) showed enhancements that correlated with the enhanced MUIR radar ion lines. IA MSBS (Magnetized Stimulated Brillouin Scatter) lines are much narrower than Wideband SEE (WSEE) lines and as a result electron temperature calculated using NSEE line offset has potential to be more accurate. This technique may therefore complement the electron temperature calculation using ISR spectra. Strength of IA MSBS lines correlate with EHIL in the MUIR spectrum during HF pump frequency variation near 3fce. Therefore, NSEE

  16. Simultaneous PMC and PMSE observations with a ground-basedlidar and SuperDARN HF radar over Syowa Station, Antarctica

    Science.gov (United States)

    Suzuki, Hidehiko; Nakamura, Takuji; Tsutsumi, Masaki; Kawahara, Takuya D.; Ogawa, Tadahiko; Tomikawa, Yoshihiro; Ejiri, Mitsumu K.; Sessai Yukimatu, Akira; Abo, Makoto

    2012-07-01

    A Rayleigh-Raman lidar system had been installed by the 52nd JapaneseAntarctic Research Expedition on February, 2011 at Syowa Station Antarctica(69.0°S, 39.5°E). Polar Mesospheric Cloud (PMC) was detected by the lidar at22:30UT (+3hr for LT) on Feb 4th, 2011, the first day of a routineoperation. This event is the first time to detect PMC over Syowa Station bya lidar. In the same night, SuperDARN HF radar with oblique incidence beamsalso detected Polar Mesosphere Summer Echoes (PMSEs) during 21:30UT to23:00UT. Although these signals were detected at different times andlocations, PMC motion estimated using horizontal wind velocities obtained bya collocated MF radar strongly suggests that they have a common origin (i.e.ice particle). We consider that this event occurred in the end of PMCactivity period at Syowa Station in the austral summer season (2010-2011),since the lidar did not detected any PMC signals on other days in February,2011. This is consistent with satellite-born PMC observations by AIM/CIPSand atmospheric temperature observations by AURA/MLS instruments.

  17. Real-Time Ionospheric Plasma Density Estimates in the Polar Cap using Simultaneous Dual Frequency Doppler Measurements at the SuperDARN McMurdo Radar

    Science.gov (United States)

    Spaleta, J.; Bristow, W. A.

    2012-12-01

    SuperDARN radars estimate plasma drift velocities from the Doppler shift observed on signals scattered from field-aligned density irregularities. The radars operate in the range of 8 MHz to 20 MHz and have ray paths covering a wide range of elevation angles, in order to maximize the range over which the scattering conditions are satisfied. Upward-propagating electromagnetic signals in this frequency range can be significantly refracted by the ionospheric plasma. The propagation paths of the refracted signals are bent earthward and at some point along this refracted path propagate perpendicular to the local magnetic field and scatter on the field-aligned density irregularities. The refraction results from gradients of the index of refraction in the ionospheric plasma. The index inside the ionosphere is lower than its free-space value, which depresses the measured line of sight velocity relative to the actual velocity of the plasma. One way to account for the depression of the measured velocity is to estimate the index of refraction in the scattering region by making multiple velocities measurements at different operating frequencies. Together with the appropriate plasma dispersion relations, multiple frequency measurements can be used to construct relations for the index of refraction, plasma density and the line of sight velocity correction factor as functions of frequency weighted measured velocity differences. Recent studies have used frequency-switching events spanning many days during traditional SuperDARN radar operation to build a statistical estimate for index of refraction, which is insensitive to the real-time spatial dynamics of the ionosphere. This statistical approach has motivated the development of a new mode of radar operation that provides simultaneous dual frequency measurements in order to resolve the temporal and spatial dynamics of the index of refraction calculations. Newly-developed multi-channel capabilities available in the SuperDARN radar

  18. Direct determination of IMF B-Y-related cusp current systems, using SuperDARN radar and multiple ground magnetometer data: A link to theory on cusp current origin

    DEFF Research Database (Denmark)

    Amm, O.; Engebretson, M.J.; Greenwald, R.A.

    1999-01-01

    We analyze an ionospheric "enhanced convection event" in the cusp on November 13, 1996, at 1900 UT, by using data of the SuperDARN radar, and of the IMAGE, Greenland, MACCS and CANOPUS magnetometer arrays; and from other magnetometer stations. The event occurs similar to 20 minutes after a transi......We analyze an ionospheric "enhanced convection event" in the cusp on November 13, 1996, at 1900 UT, by using data of the SuperDARN radar, and of the IMAGE, Greenland, MACCS and CANOPUS magnetometer arrays; and from other magnetometer stations. The event occurs similar to 20 minutes after...

  19. Statistical characteristics of Doppler spectral width as observed by the conjugate SuperDARN radars

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    K. Hosokawa

    Full Text Available We performed a statistical analysis of the occurrence distribution of Doppler spectral width around the day-side high-latitude ionosphere using data from the conjugate radar pair composed of the CUTLASS Iceland-East radar in the Northern Hemisphere and the SENSU Syowa-East radar in the Southern Hemisphere. Three types of spectral width distribution were identified: (1 an exponential-like distribution in the lower magnetic latitudes (below 72°, (2 a Gaussian-like distribution around a few degrees magnetic latitude, centered on 78°, and (3 another type of distribution in the higher magnetic latitudes (above 80°. The first two are considered to represent the geophysical regimes such as the LLBL and the cusp, respectively, because they are similar to the spectral width distributions within the LLBL and the cusp, as classified by Baker et al. (1995. The distribution found above 80° magnetic latitude has been clarified for the first time in this study. This distribution has similarities to the exponential-like distribution in the lower latitude part, although clear differences also exist in their characteristics. These three spectral width distributions are commonly identified in conjugate hemispheres. The latitudinal transition from one distribution to another exhibits basically the same trend between two hemispheres. There is, however, an interhemispheric difference in the form of the distribution around the cusp latitudes, such that spectral width values obtained from Syowa-East are larger than those from Iceland-East. On the basis of the spectral width characteristics, the average locations of the cusp and the open/closed field line boundary are estimated statistically.

    Key words. Ionosphere (ionosphere-magnetosphere inter-actions; plasma convection – Magnetospheric physics (magnetopause, cusp, and boundary layers

  20. Simultaneous PMC and PMSE observations with a ground-based lidar and SuperDARN HF radar at Syowa Station, Antarctica

    Directory of Open Access Journals (Sweden)

    H. Suzuki

    2013-10-01

    Full Text Available A Rayleigh–Raman lidar system was installed in January 2011 at Syowa Station, Antarctica (69.0° S, 39.6° E. Polar mesospheric clouds (PMCs were detected by lidar at around 22:30 UTC (LT −3 h on 4 February 2011, which was the first day of observation. This was the first detection of PMCs over Syowa Station by lidar. On the same day, a Super Dual Auroral Radar Network (SuperDARN HF radar with oblique-incidence beams detected polar mesospheric summer echoes (PMSE between 21:30 and 23:00 UTC. This event is regarded as the last PMC activity around Syowa Station during the austral summer season (2010–2011, since no other PMC signals were detected by lidar in February 2011. This is consistent with results of PMC and mesopause temperature observations by satellite-born instruments of AIM (Aeronomy of Ice in the Mesosphere/CIPS (Cloud Imaging and Particle Size and AURA/MLS (Microwave Limb Sounder and horizontal wind measurements taken by a separate MF radar. Doppler velocity of PMSE observed by the HF radar showed motion toward Syowa Station (westward. This westward motion is consistent with the wind velocities obtained by the MF radar. However, the PMSE region showed horizontal motion from a north-to-south direction during the PMC event. This event indicates that the apparent horizontal motion of the PMSE region can deviate from neutral wind directions and observed Doppler velocities.

  1. Simultaneous PMC and PMSE observations with a ground-based lidar and SuperDARN HF radar at Syowa Station, Antarctica

    Science.gov (United States)

    Suzuki, H.; Nakamura, T.; Ejiri, M. K.; Ogawa, T.; Tsutsumi, M.; Abo, M.; Kawahara, T. D.; Tomikawa, Y.; Yukimatu, A. S.; Sato, N.

    2013-10-01

    A Rayleigh-Raman lidar system was installed in January 2011 at Syowa Station, Antarctica (69.0° S, 39.6° E). Polar mesospheric clouds (PMCs) were detected by lidar at around 22:30 UTC (LT -3 h) on 4 February 2011, which was the first day of observation. This was the first detection of PMCs over Syowa Station by lidar. On the same day, a Super Dual Auroral Radar Network (SuperDARN) HF radar with oblique-incidence beams detected polar mesospheric summer echoes (PMSE) between 21:30 and 23:00 UTC. This event is regarded as the last PMC activity around Syowa Station during the austral summer season (2010-2011), since no other PMC signals were detected by lidar in February 2011. This is consistent with results of PMC and mesopause temperature observations by satellite-born instruments of AIM (Aeronomy of Ice in the Mesosphere)/CIPS (Cloud Imaging and Particle Size) and AURA/MLS (Microwave Limb Sounder) and horizontal wind measurements taken by a separate MF radar. Doppler velocity of PMSE observed by the HF radar showed motion toward Syowa Station (westward). This westward motion is consistent with the wind velocities obtained by the MF radar. However, the PMSE region showed horizontal motion from a north-to-south direction during the PMC event. This event indicates that the apparent horizontal motion of the PMSE region can deviate from neutral wind directions and observed Doppler velocities.

  2. A Statistical study of the Doppler spectral width of high-latitude ionospheric F-region echoes recorded with SuperDARN coherent HF radars

    Directory of Open Access Journals (Sweden)

    J.-P. Villain

    Full Text Available The HF radars of the Super Dual Auroral Radar Network (SuperDARN provide measurements of the E × B drift of ionospheric plasma over extended regions of the high-latitude ionosphere. We have conducted a statistical study of the associated Doppler spectral width of ionospheric F-region echoes. The study has been conducted with all available radars from the Northern Hemisphere for 2 specific periods of time. Period 1 corresponds to the winter months of 1994, while period 2 covers October 1996 to March 1997. The distributions of data points and average spectral width are presented as a function of Magnetic Latitude and Magnetic Local Time. The databases are very consistent and exhibit the same features. The most stringent features are: a region of very high spectral width, collocated with the ionospheric LLBL/cusp/mantle region; an oval shaped region of high spectral width, whose equator-ward boundary matches the poleward limit of the Holzworth and Meng auroral oval. A simulation has been conducted to evaluate the geometrical and instrumental effects on the spectral width. It shows that these effects cannot account for the observed spectral features. It is then concluded that these specific spectral width characteristics are the signature of ionospheric/magnetospheric coupling phenomena.

    Key words. Ionosphere (auroral ionosphere; ionosphere-magnetosphere interactions; ionospheric irregularities

  3. Observations of storm time midlatitude ion-neutral coupling using SuperDARN radars and NATION Fabry-Perot interferometers

    Science.gov (United States)

    Joshi, P. P.; H. Baker, J. B.; Ruohoniemi, J. M.; Makela, J. J.; Fisher, D. J.; Harding, B. J.; Frissell, N. A.; Thomas, E. G.

    2015-10-01

    Ion drag is known to play an important role in driving neutral thermosphere circulation at auroral latitudes, especially during the main phase of geomagnetic storms. During the recovery phase, the neutrals are known to drive the ions and generate ionospheric electric fields and currents via the disturbance dynamo mechanism. At midlatitudes, the precise interplay between ions and neutrals is less understood largely because of the paucity of measurements that have been available. In this work, we investigate ion-neutral coupling at middle latitudes using colocated ion drift velocity measurements obtained from Super Dual Auroral Radar Network radars and neutral wind velocity and temperature measurements obtained from the North American Thermosphere Ionosphere Observing Network (NATION) Fabry-Perot interferometers. We examine one recent storm period on 2-3 October 2013 during both the main phase and late recovery phase. By using ion-neutral momentum exchange theory and a time-lagged correlation analysis, we analyze the coupling time scales and dominant driving mechanisms. We observe that during the main phase the neutrals respond to the ion convection on a time scale of ˜84 min which is significantly faster than what would be expected from local ion drag momentum forcing alone. This suggests that other storm time influences are important for driving the neutrals during the main phase, such as Joule heating. During the late recovery phase, the neutrals are observed to drive the ion convection without any significant time delay, consistent with the so-called "neutral fly wheel effect" or disturbance dynamo persisting well into the late recovery phase.

  4. The accuracy of using the spectral width boundary measured in off-meridional SuperDARN HF radar beams as a proxy for the open-closed field line boundary

    Science.gov (United States)

    Chisham, G.; Freeman, M. P.; Sotirelis, T.; Greenwald, R. A.

    2005-10-01

    Determining reliable proxies for the ionospheric signature of the open-closed field line boundary (OCB) is crucial for making accurate measurements of magnetic reconnection. This study compares the latitudes of spectral width boundaries (SWBs) measured by different beams of the Goose Bay radar of the Super Dual Auroral Radar Network (SuperDARN), with the latitudes of OCBs determined using the low-altitude Defense Meteorological Satellite Program (DMSP) spacecraft, in order to determine whether the accuracy of the SWB as a proxy for the ionospheric projection of the OCB depends on the line-of-sight direction of the radar beam. The latitudes of SWBs and OCBs were identified using automated algorithms applied to 5 years (1997 2001) of data measured in the 1000 1400 magnetic local time (MLT) range. Six different Goose Bay radar beams were used, ranging from those aligned in the geomagnetic meridional direction to those aligned in an almost zonal direction. The results show that the SWB is a good proxy for the OCB in near-meridionally-aligned beams but becomes progressively more unreliable for beams greater than 4 beams away from the meridional direction. We propose that SWBs are identified at latitudes lower than the OCB in the off-meridional beams due to the presence of high spectral width values that result from changes in the orientation of the beams with respect to the gradient in the large-scale ionospheric convection pattern. Keywords. Ionosphere (Instruments and techniques; Plasma convection) Magnetospheric physics (Magnetopause, cusp and boundary layers)

  5. SuperDARN convection and Sondrestrom plasma drift

    Directory of Open Access Journals (Sweden)

    L. Xu

    Full Text Available Plasma convection measurements by the Goose Bay and Stokkseyri SuperDARN radar pair and the Sondrestrom incoherent scatter radar are compared in three different ways, by looking at the line-of-sight (l-o-s velocities, by comparing the SuperDARN vectors and corresponding Sondrestrom l-o-s velocities and by comparing the end products of the instruments, the convection maps. All three comparisons show overall reasonable agreement of the convection measurements though the data spread is significant and for some points a strong disagreement is obvious. The convection map comparison shows a tendency for the SuperDARN velocities to be often less than the Sondrestrom drifts for strong flows (velocities > 1000 m/s and larger for weak flows (velocities < 500 m/s. On average, both effects do not exceed 35%. Data indicate that inconsistencies between the two data sets occur largely at times of fast temporal variations of the plasma drift and for strongly irregular flow ac-cording to the SuperDARN convection maps. These facts indicate that the observed discrepancies are in many cases a result of the different spatial and temporal resolutions of the instruments.

    Key words. Ionosphere (ionospheric irregularities; plasma convection; polar ionosphere

  6. Comparison of DMSP cross-track ion drifts and SuperDARN line-of-sight velocities

    Directory of Open Access Journals (Sweden)

    R. A. Drayton

    2005-10-01

    Full Text Available Cross-track ion drifts measured by the DMSP satellites are compared with line-of-sight SuperDARN HF velocities in approximately the same directions. Good overall agreement is found for a data set comprising of 209 satellite passes over the field of view of nine SuperDARN radars in both the Northern and Southern Hemispheres. The slope of the best linear fit line relating the SuperDARN and DMSP velocities is of the order of 0.7 with a tendency for SuperDARN velocities to be smaller. The agreement implies that the satellite and radar data can be merged into a common set provided that spatial and temporal variations of the velocity as measured by both instruments are smooth.

    Keywords. Ionosphere (Ionospheric irregularities; Plasma convection; Auroral ionosphere

  7. 1993 Hokkaido, Japan Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On July 12, 1993, a magnitude 7.6 Ms (7.7 Mw) (HRV) earthquake at 13:17 UT in the Sea of Japan near Hokkaido caused a back-arc tsunami that caused damage in all of...

  8. Detection of Transionospheric SuperDARN HF Waves by the Radio Receiver Instrument on the enhanced Polar Outflow Probe Satellite

    Science.gov (United States)

    Gillies, R. G.; Yau, A. W.; James, H. G.; Hussey, G. C.; McWilliams, K. A.

    2014-12-01

    The enhanced Polar Outflow Probe (ePOP) Canadian small-satellite was launched in September 2013. Included in this suite of eight scientific instruments is the Radio Receiver Instrument (RRI). The RRI has been used to measure VLF and HF radio waves from various ground and spontaneous ionospheric sources. The first dedicated ground transmission that was detected by RRI was from the Saskatoon Super Dual Auroral Radar Network (SuperDARN) radar on Nov. 7, 2013 at 14 MHz. Several other passes over the Saskatoon SuperDARN radar have been recorded since then. Ground transmissions have also been observed from other radars, such as the SPEAR, HAARP, and SURA ionospheric heaters. However, the focus of this study will be on the results obtained from the SuperDARN passes. An analysis of the signal recorded by the RRI provides estimates of signal power, Doppler shift, polarization, absolute time delay, differential mode delay, and angle of arrival. By comparing these parameters to similar parameters derived from ray tracing simulations, ionospheric electron density structures may be detected and measured. Further analysis of the results from the other ground transmitters and future SuperDARN passes will be used to refine these results.

  9. Sapporo, Hokkaido, Japan

    Science.gov (United States)

    1992-01-01

    The city of Sapporo on the northernmost of the Japanese Home Island of Hokkaido (43.5N, 141.5E), host to the 1986 Winter Olympic Games is situated along the margin of a large valley which extends across the island from the Sea of Japan to the Pacific Ocean. The Valley is largely cultivated (the lighter green of the cultivated land distinguishes it from the gray urban development of Sapporo), but much of the island remains heavily forested.

  10. Temporal and spatial resolved SuperDARN line of sight velocity measurements corrected for plasma index of refraction using Bayesian inference

    Science.gov (United States)

    Spaleta, J.; Bristow, W. A.; Klein, J.

    2015-04-01

    Recent work by Gillies et al. (2012, 2009, 2010) has sought an explanation for the SuperDARN line-of-sight velocity underestimate of ionospheric plasma velocity. The reason for the underestimation is thought to be from the modification of the measured Doppler shift of the backscattered signal due to phase refractive index of the ionospheric plasma in the scattering region. Presented here is an analysis technique to estimate the plasma drift velocity, correcting for the index of the refraction of the scattering medium. The technique requires dual frequency SuperDARN observations and calculates velocity from the phase of the SuperDARN autocorrelation function (ACF). Both plasma velocity and plasma density are treated as independent unknowns, and self-consistent error estimates are generated for each. This new technique was employed at the McMurdo radar, resulting in estimates of plasma velocity on scales relevant to existing SuperDARN data products. The McMurdo dual frequency analysis also provides a new SuperDARN data product, an estimate for the plasma density in the ionospheric region derived wholly from SuperDARN backscatter.

  11. On the SuperDARN cross polar cap potential saturation effect

    Directory of Open Access Journals (Sweden)

    A. V. Koustov

    2009-10-01

    Full Text Available Variation of the cross polar cap potential (CPCP with the interplanetary electric field (IEF, the merging electric field EKL, the Polar Cap North (PCN magnetic index, and the solar wind-magnetosphere coupling function EC of Newell et al. (2007 is investigated by considering convection data collected by the Super Dual Auroral Radar Network (SuperDARN in the Northern Hemisphere. Winter and summer observations are considered separately. All variations considered show close to linear trend at small values of the parameters and tendency for the saturation at large values. The threshold values starting from which the non-linearity was evident were estimated to be IEF*~EKL*~3 mV/m, PCN*~3–4, and EC*~1.5×104. The data indicate that saturation starts at larger values of the above parameters and reaches larger (up to 10 kV saturation levels during summer. Conclusions are supported by a limited data set of simultaneous SuperDARN observations in the Northern (summer and Southern (winter Hemispheres. It is argued that the SuperDARN CPCP saturation levels and the thresholds for the non-linearity to be seen are affected by the method of the CPCP estimates.

  12. First results of HF radio science with e-POP RRI and SuperDARN

    Science.gov (United States)

    Perry, G. W.; James, H. G.; Gillies, R. G.; Howarth, A.; Hussey, G. C.; McWilliams, K. A.; White, A.; Yau, A. W.

    2017-01-01

    The first results from coordinated experiments between the Radio Receiver Instrument (RRI) on the Enhanced Polar Outflow Probe (e-POP) and the Super Dual Auroral Radar Network (SuperDARN) Saskatoon high frequency (HF) radar are examined for a conjunction on 8 July 2014. e-POP, a payload on the CAScade, Smallsat and IOnospheric Polar Explorer spacecraft, was located at 380 km altitude, approximately 10° north (geographic) and 2° west of Saskatoon, Canada, moving in a southeast direction. We use a matched filter technique to extract individual received SuperDARN pulses from the RRI data stream. The pulses show characteristics of propagation through the F region ionosphere: they are heavily dispersed, they show significant pulse-to-pulse variability in magnitude, and there is clear evidence that they experienced multipath propagation. We calculate the polarization parameters of the pulses and use them to identify magnetoionic phenomena such as mode-splitting and single-mode fading. These first RRI results provide compelling insight into HF radio wave propagation and show RRI's potential to significantly advance radio science.

  13. First SuperDARN polar mesosphere summer echoes observed at SANAE IV, Antarctica

    Science.gov (United States)

    Ogunjobi, Olakunle; Sivakumar, Venkataraman; Judy; Stephenson, A. E.

    For over 3 decades studies on Polar mesosphere summer echo (PMSE) is ongoing. Its causative mechanism in the Antarctic and Arctic mesopause altitude is yet to be completely understood and is partly due to few observations from Antarctica. Also important were the varied influencing factors across the observable locations. For the first time, we report the PMSE occurrence probability rates over South African National Antarctic Expedition IV (SANAE IV). A comparison is made with observation from SANAE IV magnetic conjugate vicinity, Goose Bay in Arctic region. Here, a new matching coincidence method allowing filtration of possible contaminating echoes is described and implemented for extraction of PMSE during the 2005-2007 summers. In this method, Riometer and Super Dual Auroral Radar Network (SuperDARN) measurements from SANAE IV location are matched to obtain PMSE occurrence probability rate. Whereas the seasonal and diurnal variations followed the known features of PMSE, the percentage difference in probability occurrence rate is found to be remarkable. The SANAE IV probability rate is found to be high for the summer months reaching about 50% peak around the summer solstice. When the coincidence algorithm is relaxed, we found a substantial 30% increase in PMSE occurrence rate at SANAE IV. At this time, about 100% peak is found for Goose Bay. The contribution from the ionospheric D region electron density enhancements to SuperDARN PMSE occurrence rates at locations under auroral regions will be presented.

  14. Origin of the SuperDARN broad Doppler spectra:simultaneous observation with Oersted satellite magnetometer

    Directory of Open Access Journals (Sweden)

    K. Hosokawa

    2004-01-01

    Full Text Available We perform a case study of a favorable conjunction of an overpass of the Oersted satellite with the field-of-view of the SuperDARN Syowa East radar during an interval of the southward IMF Bz. At the time, the radar observed an L-shell aligned boundary in the spectral width around the dayside ionosphere. Simultaneously, high-frequency (0.2–5Hz magnetic field fluctuations were observed by the Oersted satellite's high-time resolution magnetometer. These magnetic field fluctuations are considered to be Alfvén waves possibly associated with the particle which precipitates into the dayside high-latitude ionosphere when magnetic reconnection occurs. It has been theoretically predicted that the time-varying electric field is the dominant physical process to expand the broad HF radar Doppler spectra. Our observation clearly demonstrates that the boundary between narrow and broad spectral widths is corresponding well to the boundary in the level of the fluctuations, which supports the previous theoretical prediction. A close relationship between electric and magnetic field fluctuations and particle precipitations during southward IMF conditions has been confirmed by many authors. The present observation allows us to suggest that the boundary between narrow and broad Doppler spectral widths observed in the dayside ionosphere is connected with the signature of the open/closed field line boundary, such as the cusp particle precipitations via electric and magnetic field fluctuations for the case of the negative IMF Bz conditions.

    Key words. Ionosphere (ionosphere-magnetosphere interactions; plasma convection. Magnetospheric physics (magnetopause, cusp, and boundary layers

  15. A statistical approach for identifying the ionospheric footprint of magnetospheric boundaries from SuperDARN observations

    Directory of Open Access Journals (Sweden)

    G. Lointier

    2008-02-01

    Full Text Available Identifying and tracking the projection of magnetospheric regions on the high-latitude ionosphere is of primary importance for studying the Solar Wind-Magnetosphere-Ionosphere system and for space weather applications. By its unique spatial coverage and temporal resolution, the Super Dual Auroral Radar Network (SuperDARN provides key parameters, such as the Doppler spectral width, which allows the monitoring of the ionospheric footprint of some magnetospheric boundaries in near real-time. In this study, we present the first results of a statistical approach for monitoring these magnetospheric boundaries. The singular value decomposition is used as a data reduction tool to describe the backscattered echoes with a small set of parameters. One of these is strongly correlated with the Doppler spectral width, and can thus be used as a proxy for it. Based on this, we propose a Bayesian classifier for identifying the spectral width boundary, which is classically associated with the Polar Cap boundary. The results are in good agreement with previous studies. Two advantages of the method are: the possibility to apply it in near real-time, and its capacity to select the appropriate threshold level for the boundary detection.

  16. A Preliminary Comparison Between SuperDARN Flow Vectors and Equivalent Ionospheric Currents From the GIMA, Greenland, MACCS, THEMIS, CARISMA, and CANMOS Ground Magnetometer Arrays

    Science.gov (United States)

    Kivelson, M. G.; Amm, O.; Weygand, J. M.; Bristow, W. A.; Angelopoulos, V.; Beheshti, B.; Steinmetz, E. S.; Engebretson, M. J.; Murr, D.; Viljanen, A.; Pulkkinen, A.; Gleisner, H.; Mann, I.; Russell, C.

    2009-12-01

    With data from the GIMA, Greenland, MACCs, CARISMA, and CANMOS, and THEMIS ground magnetometer arrays, we obtain maps of equivalent ionospheric currents (EIC) over North America using the state-of-art technique based on SECS (spherical elementary currents systems) developed by Amm and Viljanen [1999] . The EIC maps can be calculated with the same time resolution as the magnetometer data, which is 10 sec. The results thus show in detail the dynamic evolution of the currents over the whole THEMIS ground network. The EIC maps can further be compared and quantitatively combined with near simultaneous images of the THEMIS all sky imager mosaics, SuperDARN RADAR data, and THEMIS spacecraft data. We find using 5 full days of SuperDARN flow vector data obtained during the northern hemisphere winter that the flows, in general, are antiparallel to the EICs. The largest differences from the antiparallel direction appear to occur during moderate to quiet geomagnetic conditions in the midnight sector. These differences are most likely the result of non-uniform conductivity in the ionosphere that influences the EIC direction.

  17. Hokkaido Nansei-Oki Tsunami, July 12, 1993

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An earthquake occurred off the west coast of Hokkaido and the small offshore island of Okushiri in the Sea of Japan. In two to five minutes the tsunami, one of the...

  18. Magnetic local time, substorm, and particle precipitation-related variations in the behaviour of SuperDARN Doppler spectral widths

    Directory of Open Access Journals (Sweden)

    M. L. Parkinson

    2004-12-01

    Full Text Available Super Dual Auroral Radar Network (DARN radars often detect a distinct transition in line-of-sight Doppler velocity spread, or spectral width, from <50ms–1 at lower latitude to >200ms–1 at higher latitude. They also detect a similar boundary, namely the range at which ionospheric scatter with large spectral width suddenly commences (i.e. without preceding scatter with low spectral width. The location and behaviour of the spectral width boundary (SWB (and scatter boundary and the open-closed magnetic field line boundary (OCB are thought to be closely related. The location of the nightside OCB can be inferred from the poleward edge of the auroral oval determined using energy spectra of precipitating particles measured on board Defence Meteorology Satellite Program (DMSP satellites. Observations made with the Halley SuperDARN radar (75.5° S, 26.6° W, geographic; –62.0°Λ and the Tasman International Geospace Environment Radar (TIGER (43.4° S, 147.2° E; –54.5°Λ are used to compare the location of the SWB with the DMSP-inferred OCB during 08:00 to 22:00 UT on 1 April 2000. This study interval was chosen because it includes several moderate substorms, whilst the Halley radar provided almost continuous high-time resolution measurements of the dayside SWB location and shape, and TIGER provided the same in the nightside ionosphere. The behaviour of the day- and nightside SWB can be understood in terms of the expanding/contracting polar cap model of high-latitude convection change, and the behaviour of the nightside SWB can also be organised according to substorm phase. Previous comparisons with DMSP OCBs have proven that the radar SWB is often a reasonable proxy for the OCB from dusk to just past midnight (Chisham et al., 2004. However, the present case study actually suggests that the nightside SWB is often a better proxy for the poleward edge of Pedersen conductance enhanced by hot particle precipitation in the

  19. The Precision Expandable Radar Calibration Sphere (PERCS) With Applications for Laser Imaging and Ranging

    Science.gov (United States)

    2008-09-01

    HF facilities such as HAARP in Alaska, EISCAT in Norway, and Arecibo in Puerto Rico; (3) the chain of high latitude SuperDARN radars used for auroral...DF arrays, ground HF transmitters such as the Navy relocatable over the horizon radar (ROTHR) and the Air Force/Navy HAARP system would be employed...United States and Australia; (2) high power HF facilities such as HAARP in Alaska, EISCAT in Norway, and Arecibo in Puerto Rico; (3) the chain of high

  20. High-latitude poynting flux from combined Iridium and SuperDARN data

    Directory of Open Access Journals (Sweden)

    C. L. Waters

    2004-09-01

    Full Text Available Field-aligned currents convey stress between the magnetosphere and ionosphere, and the associated low altitude magnetic and electric fields reflect the flow of electromagnetic energy to the polar ionosphere. We introduce a new technique to measure the global distribution of high latitude Poynting flux, S||, by combining electric field estimates from the Super Dual Auroral Radar Network (SuperDARN with magnetic perturbations derived using magnetometer data from the Iridium satellite constellation. Spherical harmonic methods are used to merge the data sets and calculate S|| for any magnetic local time (MLT from the pole to 60° magnetic latitude (MLAT. The effective spatial resolutions are 2° MLAT, 2h MLT, and the time resolution is about one hour due to the telemetry rate of the Iridium magnetometer data. The technique allows for the assessment of high-latitude net S|| and its spatial distribution on one hour time scales with two key advantages: (1 it yields the net S|| including the contribution of neutral winds; and (2 the results are obtained without recourse to estimates of ionosphere conductivity. We present two examples, 23 November 1999, 14:00-15:00 UT, and 11 March 2000, 16:00-17:00 UT, to test the accuracy of the technique and to illustrate the distributions of S|| that it gives. Comparisons with in-situ S|| estimates from DMSP satellites show agreement to a few mW/m2 and in the locations of S|| enhancements to within the technique's resolution. The total electromagnetic energy flux was 50GW for these events. At auroral latitudes, S|| tends to maximize in the morning and afternoon in regions less than 5° in MLAT by two hours in MLT having S||=10 to 20mW/m2 and total power up to 10GW. The power poleward of the Region 1 currents is about one

  1. SuperDARN studies of the ionospheric convection response to a northward turning of the interplanetary magnetic field

    Directory of Open Access Journals (Sweden)

    J. R. Taylor

    Full Text Available The response of the dayside ionospheric flow to a sharp change in the direction of the interplanetary magnetic field (IMF measured by the WIND spacecraft from negative Bz and positive By, to positive Bz and small By, has been studied using SuperDARN radar, DMSP satellite, and ground magnetometer data. In response to the IMF change, the flow underwent a transition from a distorted twin-cell flow involving antisunward flow over the polar cap, to a multi-cell flow involving a region of sunward flow at high latitudes near noon. The radar data have been studied at the highest time resolution available (~2 min to determine how this transition took place. It is found that the dayside flow responded promptly to the change in the IMF, with changes in radar and magnetic data starting within a few minutes of the estimated time at which the effects could first have reached the dayside ionosphere. The data also indicate that sunward flows appeared promptly at the start of the flow change (within ~2 min, localised initially in a small region near noon at the equatorward edge of the radar backscatter band. Subsequently the region occupied by these flows expanded rapidly east-west and poleward, over intervals of ~7 and ~14 min respectively, to cover a region at least 2 h wide in local time and 5° in latitude, before rapid evolution ceased in the noon sector. In the lower latitude dusk sector the evolution extended for a further ~6 min before quasi-steady conditions again prevailed within the field-of-view. Overall, these observations are shown to be in close conformity with expectations based on prior theoretical discussion, except for the very prompt appearance of sunward flows after the onset of the flow change.

    Key words. Ionosphere (Auroral ionosphere · Magnetospheric physics (Magnetopause · cusp · and boundary layers; Magnetosphere · ionosphere interaction

  2. PMSE long term observations using SuperDARN SANAE HF radar measurements

    National Research Council Canada - National Science Library

    Olakunle Ogunjobi; Venkataraman Sivakumar; Judy Ann Elizabeth Stephenson; Zolile Mtumela

    2017-01-01

    .... These strong backscatters are referred to as Polar Mesosphere Summer Echoes (PMSE). Although studies on PMSE have been ongoing for over three decades, aspects revealed by various instruments are still the subject of discussion...

  3. Geothermal gradients map of Hokkaido; Hokkaido no chion kobaizu ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Akita, F.; Matsunami, T.; Wakahama, H. [Hokkaido Geological Survey, Sapporo (Japan)

    1997-06-15

    This paper outlines the newly prepared geothermal gradient map (GGM) of Hokkaido which is important for survey on geothermal and hot spring resources. The temperature data of 687 wells were compiled by data collection and field survey. The geothermal gradient was calculated from the ratio of the temperature difference between the bottom (deepest well log) and the ground surface (10degC) to a bottom depth. GGM was prepared using data of 85 wells which show real geothermal temperatures through conductive temperature profiles, or SBHT (static bottom hole temperature) calculation is possible. Geological profiles were classified into three types based on base rocks. The thermal structure of GGM was clearly divided into a high geothermal gradient over 10degC/100m, and a low one within 3degC/100m. The former showed active volcano and high geothermal areas, while the latter showed a volcanic front arc area. This underground temperature structure relates to the formation process of volcanos and the origin of magma, and is also similar to the trend of a crust thermal flow rate. The geothermal gradient increases with a decrease in Curie point depth. 26 refs., 10 figs., 2 tabs.

  4. The Vision and Challenges of Hokkaido Pharmaceutical University's Affiliated Pharmacy.

    Science.gov (United States)

    Norose, Takahiko; Manabe, Tomohiro; Furuta, Seiichi; Watanabe, Kazuhiro

    2016-01-01

    Hokkaido Pharmaceutical University (HPU), according to its educational mission, seeks to "develop medical professionals who contribute to community medicine", and it has produced more than 6300 graduates since 1974. With recent medical advancements and a progressively aging society, the role of the pharmacist in community medicine has diversified and is increasing in importance. Therefore, in April 2012, the Hokkaido Pharmaceutical University Affiliated Pharmacy was established as a for-profit business of the Educational Foundation of the Hokkaido University of Science, the parent body of HPU. The pharmacy is located near the Sapporo station; it is operated by six pharmacists and four clerks, and supported by three faculty members who are engaged in providing HPU student education such as on-site clinical training, in addition to their pharmacy duties such as home care pharmaceutics. For the first two years it was open, the pharmacy focused on the establishment of pharmacy administration and fiscal consolidation. In April 2015, the Pharmacy Management Committee set the pharmacy's future vision, as well as its mid-term strategy, which consists of the four main components of pharmacy practices, education, research, and social contribution, in order for the pharmacy to serve as a model of community pharmacy.

  5. HF radar transmissions that deviate from great-circle paths: new insight from e-POP RRI

    Science.gov (United States)

    Perry, G. W.; Miller, E. S.; James, H. G.; Howarth, A. D.; St-Maurice, J. P.; Yau, A. W.

    2016-12-01

    Significant deviations of SuperDARN radar transmissions from their expected great-circle paths have been detected at ionospheric altitudes using the Radio Receiver Instrument (RRI) on the Enhanced Polar Outflow Probe (e-POP). Experiments between SuperDARN Rankin Inlet and e-POP RRI were conducted at similar local times over consecutive days. Customized experiment modes which incorporated the agile frequency switching capabilities of each system were used. The RRI measurements show deviations of radar transmissions from their expected paths by as much as 2 or 3 SuperDARN beam widths, equivalent to 6° - 10° in bearing from Rankin Inlet. The deviations displayed a dependence on the radar carrier frequency and a day-to-day variability, suggesting that the deviations were transient in nature. We will discuss the deviations in the context of 3D ray trace modeling and measurements from the Resolute Bay Incoherent Scatter Radar - North (RISR-N). The latter provided diagnostic information of the ionosphere along the ray path between RRI and Rankin Inlet during the experiments.

  6. First imaging and identification of a noctilucent cloud from multiple sites in Hokkaido (43.2-44.4°N), Japan

    Science.gov (United States)

    Suzuki, Hidehiko; Sakanoi, Kazuyo; Nishitani, Nozomu; Ogawa, Tadahiko; Ejiri, Mitsumu K.; Kubota, Minoru; Kinoshita, Takenori; Murayama, Yasuhiro; Fujiyoshi, Yasushi

    2016-11-01

    Simultaneous imaging observations of a noctilucent cloud (NLC) from five sites in Hokkaido, Japan (43.17-45.36°N), were successfully carried out using digital cameras in the early hours of the morning (around 02:00 LST) on June 21, 2015. This is the first NLC event that has been captured from multiple sites in Japan. The simultaneous images obtained from multiple sites made it possible to calculate the exact altitude (=83.9 ± 0.1 km) and spatial distribution (47.5-50.0°N and 143.0-147.5°E) of the NLC by triangulation and image correlation methods. Based on a comparison of atmospheric parameters of the upper mesosphere provided by satellites and a middle-frequency (MF) radar in northern Hokkaido (Wakkanai) with the cloud distribution obtained from the Aeronomy of Ice in the Mesosphere satellite, this particular event is considered to be the result of southward advection of the NLC from a higher-latitude (i.e., colder) region. Anomalies in the upper mesospheric temperature of the northern hemispheric summer in 2015 were examined using AURA satellite data, because this is the first NLC event that has been identified in Japan. However, no remarkable temperature variations relative to other years were found in upper mesosphere. Based on a comparison between the NLC period and the record of sky conditions archived by the Japan Meteorological Agency, a high percentage of cloud (especially low-level) cover during the summer in Hokkaido cannot be ruled out as a possible reason why the NLC had not previously been sighted in Hokkaido.[Figure not available: see fulltext.

  7. Genetic uniformity of Echinococcus multilocularis collected from different intermediate host species in Hokkaido, Japan.

    Science.gov (United States)

    Okamoto, Munehiro; Oku, Yuzaburo; Kurosawa, Tsutomu; Kamiya, Masao

    2007-02-01

    DNA from several isolates of Taenia taeniaeformis and Echinococcus multilocularis were digested with restriction enzymes and hybridized with digoxigenated oligonucleotide probe (CAC)5. Within the six wild isolates of Taenia taeniaeformis from Norway rats in Hokkaido, although several bands were common among isolates, fingerprinting patterns were specific to each isolate. In the case of E. multilocularis, regardless of hosts from which each isolate has been isolated, the five isolates collected from Hokkaido, showed the same fingerprinting pattern. These results indicate that there was very little genetic difference among these isolates. Although the fingerprinting pattern of E. multilocularis from St. Lawrence Is. was similar to that of the Hokkaido isolates, some bands were different from those in the Hokkaido isolates. Echinococcus multilocularis in Hokkaido seems to be closely-related genetically to that from St. Lawrence Is.

  8. Pulsed flows at the high-altitude cusp poleward boundary, and associated ionospheric convection and particle signatures, during a Cluster - FAST - SuperDARN- Søndrestrøm conjunction under a southwest IMF

    Directory of Open Access Journals (Sweden)

    C. J. Farrugia

    2004-09-01

    Full Text Available Particle and magnetic field observations during a magnetic conjunction Cluster 1-FAST-Søndrestrøm within the field of view of SuperDARN radars on 21 January 2001 allow us to draw a detailed, comprehensive and self-consistent picture at three heights of signatures associated with transient reconnection under a steady south-westerly IMF (clock angle ≈130°. Cluster 1 was outbound through the high altitude (~12RE exterior northern cusp tailward of the bifurcation line (geomagnetic Bx>0 when a solar wind dynamic pressure release shifted the spacecraft into a boundary layer downstream of the cusp. The centerpiece of the investigation is a series of flow bursts observed there by the spacecraft, which were accompanied by strong field perturbations and tailward flow deflections. Analysis shows these to be Alfvén waves. We interpret these flow events as being due to a sequence of reconnected flux tubes, with field-aligned currents in the associated Alfvén waves carrying stresses to the underlying ionosphere, a view strengthened by the other observations. At the magnetic footprint of the region of Cluster flow bursts, FAST observed an ion energy-latitude disperison of the stepped cusp type, with individual cusp ion steps corresponding to individual flow bursts. Simultaneously, the SuperDARN Stokkseyri radar observed very strong poleward-moving radar auroral forms (PMRAFs which were conjugate to the flow bursts at Cluster. FAST was traversing these PMRAFs when it observed the cusp ion steps. The Søndrestrøm radar observed pulsed ionospheric flows (PIFs just poleward of the convection reversal boundary. As at Cluster, the flow was eastward (tailward, implying a coherent eastward (tailward motion of the hypothesized open flux tubes. The joint Søndrestrøm and FAST observations indicate that the open/closed field line boundary was equatorward of the convection reversal boundary by ~2°. The unprecedented accuracy

  9. Three-dimensional analysis of the magnetic structure in Hokkaido, Japan; Hokkaido no sanjigen jiki kozo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Makino, M. [Geological Survey of Japan, Tsukuba (Japan)

    1996-10-01

    The magnetic structure in Hokkaido was quantitatively analyzed by the magnetic anomaly distribution. This paper describes its characteristics. Detection of structural boundaries and 3-D analysis of double-layer structure were conducted for the regional magnetic data in a region with about 500 km square. There was not so large difference in patterns of magnetic anomaly distribution between the case that the direction of magnetization was set at 45{degree} to the west during the geomagnetic conversion according to Segawa and Oshima and the case that it was set as same as the current geomagnetic direction. The method of Blakely and Simpson was useful to detect the boundaries of magnetic structures. The structural boundaries obtained were more linear than the iso-magnetic contour lines. A new method has been conceived in which the approximation of 3-D magnetic structure analysis can be deduced, and the irregularity of magnetic basement can be determined by the repeated calculation. In practice, this method was applied to the magnetic data in the whole Hokkaido. The calculation was stably converged. It was found that the magnetic structure obtained in the Kamuikotan/Ishikari-Kitakami magnetic belt exhibited a fault structure having steep slopes accompanied by the basin structure in the western boundaries. 19 refs., 6 figs.

  10. [Cooperation with drug addiction rehabilitation center in Hokkaido area].

    Science.gov (United States)

    Ashizawa, Takeshi

    2012-10-01

    There are about sixty therapeutic communities for drug dependence called DARC (Drug Addiction Rehabilitation Center) that is the only rehabilitation facilities managed by staffs recovered from drug dependence to use the method of twelve steps in Japan. DARC plays an important role to resolve problems of drug dependence. The subject matter of this paper concerns how medical services should cooperate with DARC. A few studies had pointed out that DARC had some outstanding problems. But there have been no studies based on longitudinal observations. I have been cooperating with DARC in Hokkaido area (HDARC) for seven years. I reported the prognosis and the employment in the users of HDARC, as well as the foundation and the management of HDARC. I explained my policies that I did not prescribe benzodiazepine and its analogs, and that I did not urinalysis to detect illicit drugs. I discussed the meaning of recovered counselors, therapeutic communities for drug dependence and drug court in Japan.

  11. Arctic and Antarctic polar mesosphere summer echoes observed with oblique incidence HF radars: analysis using simultaneous MF and VHF radar data

    Directory of Open Access Journals (Sweden)

    T. Ogawa

    2004-12-01

    Full Text Available Polar mesosphere summer echoes (PMSEs have been well studied using vertical incidence VHF radars at northern high-latitudes. In this paper, two PMSE events detected with the oblique incidence SuperDARN HF radars at Hankasalmi, Finland (62.3° N and Syowa Station, Antarctica (69.0° S, are analyzed, together with simultaneous VHF and medium-frequency (MF radar data. Altitude resolutions of the HF radars in the mesosphere and the lower thermosphere are too poor to know exact PMSE altitudes. However, a comparison of Doppler velocity from the HF radar and neutral wind velocity from the MF radar shows that PMSEs at the HF band appeared at altitudes within 80-90km, which are consistent with those from previous vertical incidence HF-VHF radar results. The HF-VHF PMSE occurrences exhibit a semidiurnal behavior, as observed by other researchers. It is found that in one event, PMSEs occurred when westward semidiurnal winds with large amplitude at 85-88km altitudes attained a maximum. When the HF-VHF PMSEs were observed at distances beyond 180km from MF radar sites, the MF radars detected no appreciable signatures of echo enhancement.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides

  12. Nitrous oxide fluxes from upland soils in central Hokkaido, Japan

    Institute of Scientific and Technical Information of China (English)

    MU Zhijian; Sonoko D. KIMURA; Yo TOMA; Ryusuke HATANO

    2008-01-01

    Nitrous oxide (N2O) fluxes from soils were measured using the closed chamber method during the snow-free seasons (middle April to early November), for three years, in a total of 11 upland crop fields in central Hokkaido, Japan. The annual mean N2O fluxes ranged fluxes showed a large temporal variation with peak emissions generally occurring following fertilization and heavy rainfall events around harvesting in autumn. No clear common factor regulating instantaneous N2O fluxes was found at any of the study sites. Instead,instantaneous N2O fluxes at different sites were affected by different soil variables. The cumulative N2O emissions during the study period within each year varied from 0.15 to 7.05 kgN/hm2 for different sites, which accounted for 0.33% to 5.09% of the applied fertilizer N. No obvious relationship was observed between cumulative N2O emission and applied fertilizer N rate (P>0.4). However,the cumulative N2O emission was significantly correlated with gross mineralized N as estimated by CO2 emissions from bare soils divided by C/N ratios of each soil, and with soil mineral N pool (I.e., the sum of gross mineralized N and fertilizer N) (P<0.001).

  13. Quantum radar

    CERN Document Server

    Lanzagorta, Marco

    2011-01-01

    This book offers a concise review of quantum radar theory. Our approach is pedagogical, making emphasis on the physics behind the operation of a hypothetical quantum radar. We concentrate our discussion on the two major models proposed to date: interferometric quantum radar and quantum illumination. In addition, this book offers some new results, including an analytical study of quantum interferometry in the X-band radar region with a variety of atmospheric conditions, a derivation of a quantum radar equation, and a discussion of quantum radar jamming.This book assumes the reader is familiar w

  14. Load leveling efforts of The Hokkaido Electric Power Co. Inc.; Hokkaido Denryoku no fuka heijunka eno torikumi ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The Hokkaido Electric Power Co., Inc., aiming to enhance power generation efficiency through power load levelling, strives to expand and substantiate its electricity billing menu and to popularize and encourage the use of levelling-oriented apparatuses and systems most of which are designed for utilizing midnight power. The billing menu has in it a snow-melting power which is cut off for load levelling during the peak demand time zone. For domestic use, a time zone-specified lighting system named Dream Eight is created, which is one of the billing systems dependent upon time zone. Introduced therein for industrial use is a demand/supply adjustment contract system. Furthermore, in compliance with the amended Electricity Business Law that came into force in 1995, efforts are under way for revising the period wherein power is to be supplied for melting snow, expanding the scope of application of the power supply system dependent upon time zone, and newly introducing a heat accumulation assisted peak adjustment contract system and an operation adjustment contract system. As for business efforts in relation to load levelling, the company proposes household electrical systems centering about 200V high-efficiency apparatuses, electric water warmer contributing to the enhancement of year-round load levelling, popularization and reinforcement of electric snow melting systems, and power utilizing technologies capable of meeting local demands raised for example by agriculture and fishery.

  15. Prevalence of human T-lymphotropic virus type 1 carriers among pregnant women in Hokkaido, Japan.

    Science.gov (United States)

    Yamada, Takahiro; Togashi, Takehiro; Tsutsumi, Hiroyuki; Imamura, Masahiro; Okubo, Hitoshi; Okabe, Mihiro; Takamuro, Noriko; Tashiro, Kunio; Yano, Koichi; Yamamoto, Nagafumi; Hirakawa, Yukiko; Minakami, Hisanori

    2014-08-01

    As there is a risk of MTCT of HTLV-1, the HSGP HTLV-1 MTCT was organized in 2011. To determine how many pregnant women are infected with HTLV-1 in Hokkaido, which is the northernmost and the second largest island in Japan with a population of 5,467,000 and 39,392 newborns in 2011, the HSGP HTLV-1 MTCT asked all facilities that may care for pregnant women in Hokkaido in July 2013 to provide information on the number of pregnant women who underwent screening for anti-HTLV-1 antibody using particle agglutination or chemiluminescent enzyme immunoassay, and the numbers of those with positive, equivocal, and negative test results in the screening and confirmation tests using western blotting or PCR methods in 2012, respectively. A total of 111 facilities participated in this study and provided information on 33,617 pregnant women who underwent screening in 2012, corresponding to approximately 85% of all pregnant women who gave birth in Hokkaido in 2012. Of 81 candidates for a confirmation test because of positive (n = 77) or equivocal (n = 4) results on screening, 63 (78%) underwent the confirmation test and, finally, 34 (0.1%) and 33,563 (99.8%) women were judged to be HTLV-1 carriers and non-carriers, respectively. It was concluded that the prevalence rate of HTLV-1 carriers was low, one per 1000 pregnant women in Hokkaido. Approximately 40 infants are born yearly to mothers infected with HTLV-1 in Hokkaido.

  16. Radar Chart

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Radar Chart collection is an archived product of summarized radar data. The geographic coverage is the 48 contiguous states of the United States. These hourly...

  17. Detecting Seismicity Rate Transients in the Hokkaido Corner

    Science.gov (United States)

    Llenos, A. L.; McGuire, J. J.; Ogata, Y.

    2009-12-01

    Transient aseismic processes alter the stress state of a region and can cause seismicity rate anomalies in space and time detectable by models such as the Epidemic Type Aftershock Sequence (ETAS) model (Ogata, 1988). The presence of such anomalies in subduction zones can therefore indicate stress changes are occurring due to processes such as afterslip or slow slip events. The Hokkaido corner in northeastern Japan is a good region to investigate these anomalies and their relationship to frictional conditions on the plate interface. This area consists of several asperities that rupture in great earthquakes such as the 2003 M8.3 Tokachi-oki earthquake. The abundance of high quality seismic and geodetic data for that event have led to the development of detailed coseismic and postseismic slip models (e.g., Yamanaka and Kikuchi, 2003; Miyazaki et al., 2004), from which stress changes can be inferred and compared to spatial and temporal variations in seismicity rate behavior. For example, an analysis of central Japan seismicity suggests that high aftershock productivities tend to cluster on the updip boundaries of major asperities (Ogata, 2005). Elevated stressing rates due to afterslip can also cause increased levels of background seismicity on the fault patches where afterslip is occurring. Therefore, mapping where these anomalies occur can lead to a better understanding of where and how stress is accumulating on the megathrust. We have developed a method that can directly map seismicity rate anomalies to the stressing rate changes due to aseismic processes. Because aftershocks often obscure changes in the background seismicity caused by these processes, we combine two models commonly used to estimate the time dependence of underlying driving mechanisms, the stochastic ETAS model and the physically based rate- and state-dependent friction model (Dieterich, 1994), into a single seismicity rate model that can explain both aftershock activity as well as changes in

  18. Radar Fundamentals, Presentation

    OpenAIRE

    Jenn, David

    2008-01-01

    Topics include: introduction, radar functions, antennas basics, radar range equation, system parameters, electromagnetic waves, scattering mechanisms, radar cross section and stealth, and sample radar systems.

  19. Radar Fundamentals, Presentation

    OpenAIRE

    Jenn, David

    2008-01-01

    Topics include: introduction, radar functions, antennas basics, radar range equation, system parameters, electromagnetic waves, scattering mechanisms, radar cross section and stealth, and sample radar systems.

  20. Radar equations for modern radar

    CERN Document Server

    Barton, David K

    2012-01-01

    Based on the classic Radar Range-Performance Analysis from 1980, this practical volume extends that work to ensure applicability of radar equations to the design and analysis of modern radars. This unique book helps you identify what information on the radar and its environment is needed to predict detection range. Moreover, it provides equations and data to improve the accuracy of range calculations. You find detailed information on propagation effects, methods of range calculation in environments that include clutter, jamming and thermal noise, as well as loss factors that reduce radar perfo

  1. Crustal temperature structure derived from a ground temperature gradient chart of Hokkaido; Hokkaido no chion kobaizu kara motometa chikakunai ondo kozo

    Energy Technology Data Exchange (ETDEWEB)

    Okubo, Y. [Geological Survey of Japan, Tsukuba (Japan); Akita, F. [Hokkaido Geological Survey, Sapporo (Japan); Nagumo, S. [Oyo Corp., Tokyo (Japan)

    1997-05-27

    The Hokkaido Underground Resources Investigation Institute has prepared in 1995 a detailed temperature gradient chart that shows local anomalies around volcanoes. This paper describes an attempt to derive crustal temperature structure of Hokkaido from the above data. The model was hypothesized as a primary model in which no thermal convection exists. In volcanic and geothermal areas which show a temperature gradient of more than 100 {degree}C km {sup -1}, a solidus temperature is reached at a depth shallower than 10 km. Below the volcanic chain forming the Chishima arc, a partially melted region exists in a width of about 100 km. Most of the areas in the southern Hokkaido have the temperature reached the solidus temperature in the crust. On the other hand, in most of the areas of the forefront side, no solidus temperature is reached in the crust. In the temperature structure of a cross section crossing almost orthogonally with the volcanic front passing through Mt. Daisetsu, a high temperature area reaches to a shallow portion beneath Mt. Daisetsu, where the depth at which the solidus temperature is reached is 10 km or shallower. The range of area where the solidus depth is shallower than 10 km has a south-west width of about 40 km. This means that a partially melted area with a size of 40 km in the horizontal direction exists at a depth of several kilometers. 20 refs., 3 figs.

  2. Investigation of third gyro-harmonic heating at HAARP using stimulated radio emissions and the MUIR and Kodiak radars

    Science.gov (United States)

    Mahmoudian, A.; Scales, W. A.; Watkins, B. J.; Bernhardt, P. A.; Isham, B.; Vega-Cancel, O.; Ruohoniemi, J. M.

    2017-01-01

    This paper presents data from two campaigns at the High Frequency Active Auroral Research Program facility (HAARP) in 2011 and 2012. The measurements of stimulated radio emissions (often called stimulated electromagnetic emissions or SEE) were conducted 15 km from the HAARP site. The potential of Narrowband SEE (NSEE) as a new diagnostic tool to monitor artificial irregularities excited during HF-pump heating of the ionosphere is the main goal of this paper. This has been investigated using well established diagnostics including the Modular UHF Ionospheric Radar (MUIR) and Kodiak SuperDARN radars as well as Wideband SEE (WSEE). The measured data using these three diagnostics were compared to characterize the ionospheric parameters and study the plasma irregularities generated in the interaction region. Variation of the wideband/narrowband SEE features, SuperDARN echoes, and HF-enhanced ion lines (EHIL) were studied with pump power variation, pump frequency stepping near the third electron gyro-frequency (3fce) as well as changing beam angle relative to the magnetic zenith. In particular, electrostatic plasma waves and associated irregularities excited near the reflection resonance layer as well as the upper-hybrid resonance layer are investigated. The time evolution and growth rate of these irregularities are studied using the experimental observations. Close alignment of narrowband SEE (NSEE) with wideband SEE (WSEE) and EHIL was observed. SuperDARN radar echoes and WSEE also showed alignment as in previous investigations. Correlations between these three measurements underscore potential diagnostics by utilizing the NSEE spectrum to estimate ionospheric parameters such as electron temperature.

  3. Thermal structure and intermediate-depth seismicity in the Tohoku-Hokkaido subduction zones

    Energy Technology Data Exchange (ETDEWEB)

    Van Keken, P.E. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Earth and Environmental Sciences; Kita, S.; Nakajima, J. [Tohoku Univ., Sendai (Japan). Research Center for Prediction of Earthquakes and Volcanic Eruptions

    2012-07-01

    The cause of intermediate-depth (>40 km) seismicity in subduction zones is not well understood. The viability of proposed mechanisms, which include dehydration embrittlement, shear instabilities and the presence of fluids in general, depends significantly on local conditions, including pressure, temperature and composition. The wellinstrumented and well-studied subduction zone below Northern Japan (Tohoku and Hokkaido) provides an excellent testing ground to study the conditions under which intermediate-depth seismicity occurs. This study combines new finite element models that predict the dynamics and thermal structure of the Japan subduction system with a high-precision hypocenter data base. The upper plane of seismicity is principally contained in the crustal portion of the subducting slab and appears to thin and deepen within the crust at depths >80 km. The disappearance of seismicity overlaps in most of the region with the predicted phase change of blueschist to hydrous eclogite, which forms a major dehydration front in the crust. The correlation between the thermally predicted blueschist-out boundary and the disappearance of seismicity breaks down in the transition from the northern Japan to Kurile arc below western Hokkaido. Adjusted models that take into account the seismically imaged modified upper mantle structure in this region fail to adequately recover the correlation that is seen below Tohoku and eastern Hokkaido. We conclude that the thermal structure below Western Hokkaido is significantly affected by timedependent, 3-D dynamics of the slab. This study generally supports the role of fluids in the generation of intermediate-depth seismicity. (orig.)

  4. Planetary Radar

    Science.gov (United States)

    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.

  5. Finland HF and Esrange MST radar observations of polar mesosphere summer echoes

    Directory of Open Access Journals (Sweden)

    T. Ogawa

    Full Text Available Peculiar near range echoes observed in summer with the SuperDARN HF radar in Finland are presented. The echoes were detected at four frequencies of 9, 11, 13 and 15 MHz at slant ranges of 105–250 km for about 100 min. Interferometer measurements indicate that the echoes are returned from 80–100 km altitudes with elevation angles of 20°–60°. Echo power (< 16 dB, Doppler velocity (between –30 and + 30 ms-1 and spectral width (< 60 ms-1 fluctuate with periods of several to 20 min, perhaps due to short–period atmospheric gravity waves. When the HF radar detected the echoes, a vertical incidence MST radar, located at Esrange in Sweden (650 km north of the HF radar site, observed polar mesosphere summer echoes (PMSE at altitudes of 80–90 km. This fact suggests that the near range HF echoes are PMSE at HF band, although both radars did not probe a common volume. With increasing radar frequency, HF echo ranges are closer to the radar site and echo power becomes weaker. Possible mechanisms to explain these features are discussed.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides; instruments and techniques

  6. Validation of the CUTLASS HF radar gravity wave observing capability using EISCAT CP-1 data

    Directory of Open Access Journals (Sweden)

    N. F. Arnold

    Full Text Available Quasi-periodic fluctuations in the returned ground-scatter power from the SuperDARN HF radars have been linked to the passage of medium-scale gravity waves. We have applied a technique that extracts the first radar range returns from the F-region to study the spatial extent and characteristics of these waves in the CUTLASS field-of-view. Some ray tracing was carried out to test the applicability of this method. The EISCAT radar facility at Tromsø is well within the CUTLASS field-of-view for these waves and provides a unique opportunity to assess independently the ability of the HF radars to derive gravity wave information. Results from 1st March, 1995, where the EISCAT UHF radar was operating in its CP-1 mode, demonstrate that the radars were in good agreement, especially if one selects the electron density variations measured by EISCAT at around 235 km. CUTLASS and EISCAT gravity wave observations complement each other; the former extends the spatial field of view considerably, whilst the latter provides detailed vertical information about a range of ionospheric parameters.

    Key words. Ionosphere (ionosphere – atmosphere interactions · Meteorology and atmospheric dynamics (thermospheric dynamics · Radio science (ionospheric propagations

  7. Convertible source system of thermal neutron and X-ray at Hokkaido University electron linac facility

    Science.gov (United States)

    Kamiyama, T.; Hara, K. Y.; Taira, H.; Sato, H.

    2016-11-01

    The convertible source system for the neutron and the X-ray imagings was installed in the 45MeV electron linear accelerator facility at Hokkaido University. The source system is very useful for a complementary imaging. The imaging measurements for a sample were performed with both beams by using a vacuum tube type image intensifier. The enhanced contrast was obtained from the dataset of the radiograms measured with the neutron and X-ray beams.

  8. Tick surveillance for relapsing fever spirochete Borrelia miyamotoi in Hokkaido, Japan.

    Directory of Open Access Journals (Sweden)

    Ai Takano

    Full Text Available During 2012-2013, a total of 4325 host-seeking adult ticks belonging to the genus Ixodes were collected from various localities of Hokkaido, the northernmost island of Japan. Tick lysates were subjected to real-time PCR assay to detect borrelial infection. The assay was designed for specific detection of the Relapsing fever spirochete Borrelia miyamotoi and for unspecific detection of Lyme disease-related spirochetes. Overall prevalence of B. miyamotoi was 2% (71/3532 in Ixodes persulcatus, 4.3% (5/117 in Ixodes pavlovskyi and 0.1% (1/676 in Ixodes ovatus. The prevalence in I. persulcatus and I. pavlovskyi ticks were significantly higher than in I. ovatus. Co-infections with Lyme disease-related spirochetes were found in all of the tick species. During this investigation, we obtained 6 isolates of B. miyamotoi from I. persulcatus and I. pavlovskyi by culture in BSK-M medium. Phylogenetic trees of B. miyamotoi inferred from each of 3 housekeeping genes (glpQ, 16S rDNA, and flaB demonstrated that the Hokkaido isolates were clustered with Russian B. miyamotoi, but were distinguishable from North American and European B. miyamotoi. A multilocus sequence analysis using 8 genes (clpA, clpX, nifS, pepX, pyrG, recG, rplB, and uvrA suggested that all Japanese B. miyamotoi isolates, including past isolates, were genetically clonal, although these were isolated from different tick and vertebrate sources. From these results, B. miyamotoi-infected ticks are widely distributed throughout Hokkaido. Female I. persulcatus are responsible for most human tick-bites, thereby I. persulcatus is likely the most important vector of indigenous relapsing fever from tick bites in Hokkaido.

  9. Asymmetric distribution of the ionospheric electric potential in the opposite hemispheres as inferred from the SuperDARN observations and FAC-based convection model

    DEFF Research Database (Denmark)

    Lukianova, R.; Hanuise, C.; Christiansen, Freddy

    2008-01-01

    -altitude satellites. Both the solar and auroral precipitation contributions are included in order to derive the ionospheric conductance. Taking into account the electrodynamic coupling of the opposite hemispheres, the model allows one to obtain the convection patterns developed simultaneously in both hemispheres......We compare the SuperDARN convection patterns with the predictions of a new numerical model of the global distribution of ionospheric electric potentials. The model utilizes high-precision statistical maps of field-aligned currents (FAC) derived from measurements made by polar-orbiting low...... for given input parameters. SuperDARN, with its database containing global northern and southern convection maps, provides the unique opportunity to compare the model predictions of electric fields with observations. In the present study we focus on the effect of significant interhemispheric asymmetry...

  10. Weather Radar Stations

    Data.gov (United States)

    Department of Homeland Security — These data represent Next-Generation Radar (NEXRAD) and Terminal Doppler Weather Radar (TDWR) weather radar stations within the US. The NEXRAD radar stations are...

  11. Bistatic radar

    CERN Document Server

    Willis, Nick

    2004-01-01

    Annotation his book is a major extension of a chapter on bistatic radar written by the author for the Radar Handbook, 2nd edition, edited by Merrill Skolnik. It provides a history of bistatic systems that points out to potential designers the applications that have worked and the dead-ends not worth pursuing. The text reviews the basic concepts and definitions, and explains the mathematical development of relationships, such as geometry, Ovals of Cassini, dynamic range, isorange and isodoppler contours, target doppler, and clutter doppler spread.Key Features * All development and analysis are

  12. Radar detection

    CERN Document Server

    DiFranco, Julius

    2004-01-01

    This book presents a comprehensive tutorial exposition of radar detection using the methods and techniques of mathematical statistics. The material presented is as current and useful to today's engineers as when the book was first published by Prentice-Hall in 1968 and then republished by Artech House in 1980. The book is divided into six parts.

  13. Quaternary forest and climate history of Hokkaido, Japan, from marine sediments

    Science.gov (United States)

    Igarashi, Yaeko

    Pollen data from Quaternary marine sediments deposited in central Hokkaido, northern Japan provide insight into northeast Asian vegetation and climatic changes over the last few million years. During the Early Pleistocene, coniferous forest, dominated by Picea and Cryptomeria japonica, and taiga composed of Larix and Picea developed under cool/wet and cold/dry climates, respectively. Strong climatic contrasts are inferred from Late Pleistocene interglacial and glacial pollen assemblages which precede the last glacial cycle. In the former, cool temperate broad-leaf forest, mainly composed of Fagus, reflects a warmer and wetter climate than now. In the latter, taiga similar to that now found in northern Sakhalin apparently flourished in Hokkaido. The composition of pollen assemblages correlated with Oxygen Isotope Stage 5, changed from cool temperate forest of Quercus, Ulmus and Juglans (Substage 5e), to Picea-Larix taiga (Substage 5d), cool temperate forest of Quercus and Ulmus (Substage 5c) and Picea-Abies forest (Substage 5b). Compared with present conditions, climate during Stage 5 in northern Japan apparently fluctuated from warmer/wetter to colder/drier. Taiga composed of Picea, Pinus and Larix indicating colder/dry conditions during Stage 4, was replaced by Picea-Abies forest and Picea-Larix taiga in Stage 3, suggesting relatively cool and cold/dry environments. Taiga and mixed forest with taiga and cool temperate components characterize Stage 2. Holocene forests with Juglans-Betula and Quercus-Juglans were succeeded by Picea and Abies during the early Holocene warm interval ˜7000 BP. Subsequently, Quercus-Ulmus and Abies-Alnus assemblages reflect climatic deterioration. 'Pan-mixed' forest has been developed in Hokkaido since 2000 BP.

  14. Flux closure during a substorm observed by Cluster, Double Star, IMAGE FUV, SuperDARN, and Greenland magnetometers

    Directory of Open Access Journals (Sweden)

    S. E. Milan

    2006-03-01

    Full Text Available We examine magnetic flux closure during an extended substorm interval on 29 August 2004 involving a two-stage onset and subsequent re-intensifications. Cluster and Double Star provide observations of magnetotail dynamics, while the corresponding auroral evolution, convection response, and substorm current wedge development are monitored by IMAGE FUV, SuperDARN, and the Greenland magnetometer chain, respectively. The first stage of onset is associated with the reconnection of closed flux in the plasma sheet; this is accompanied by a short-lived auroral intensification, a modest substorm current wedge magnetic bay, but no significant ionospheric convection enhancement. The second stage follows the progression of reconnection to the open field lines of the lobes; accompanied by prolonged auroral bulge and westward-travelling surge development, enhanced magnetic bays and convection. We find that the tail dynamics are highly influenced by ongoing dayside creation of open flux, leading to flux pile-up in the near-tail and a step-wise down-tail motion of the tail reconnection site. In all, 5 dipolarizations are observed, each associated with the closure of ~0.1 GWb of flux. Very simple calculations indicate that the X-line should progress down-tail at a speed of 20 km s-1, or 6 RE between each dipolarization.

  15. Molecular survey of rickettsial agents in feral raccoons (Procyon lotor) in Hokkaido, Japan.

    Science.gov (United States)

    Sashika, Mariko; Abe, Go; Matsumoto, Kotaro; Inokuma, Hisashi

    2010-09-01

    Rickettsial infection in feral raccoons (Procyon lotor) in Hokkaido, Japan was analyzed by molecular methods. Genus-specific nested polymerase chain reaction (PCR) analysis based on the Rickettsia citrate synthase (gltA) gene showed that 13 of 699 raccoons (1.9%) examined were positive for Rickettsia. Twelve of the 13 partial gltA sequence amplicons were successfully analyzed. The nucleotide sequence of one amplicon was identical to both Rickettsia heilongjiangensis and R. japonica, one was identical to R. felis, and the rest to R. helvetica. This is the first report on the detection of rickettsial agents in peripheral blood of raccoons.

  16. Upper boundary of the Pacific plate subducting beneath Hokkaido, Japan, estimated from ScSp phase

    OpenAIRE

    Osada, Kinue; Yoshizawa, Kazunori; YOMOGIDA, Kiyoshi

    2010-01-01

    Three-dimensional geometry of the upper boundary of the Pacific plate subducting beneath Hokkaido, Japan, was obtained using the ScSp phase: the phase converted from ScS (S wave reflected at the core-mantle boundary) to P wave at the plate boundary. Taking the advantage of a dense seismic network, "Hi-net", recently deployed across the Japanese islands, we applied several seismic array analyses to the recorded waveform data for a large nearby deep earthquake, in order to enhance very weak ScS...

  17. Physics education of Japanese national colleges of technology in local community of Hokkaido

    Science.gov (United States)

    Kushino, Akihiro; Matsui, Hidenori

    2014-03-01

    The national colleges of technology in Japan, called KOSEN, were established about 50 years ago aiming to educate 15 to 20 years old students to become engineers who were necessary in period of high economic growth of Japan. In present, environment surrounding us has changed. Examples are low birth rate in Japan and the great earthquake in Tohoku area. There are 4 KOSENs in Hokkaido and we jointly make many efforts to contribute to local community in science. We present our efforts in physics education.

  18. Development of the Experimental Photo-Nuclear Reaction Database in Hokkaido University

    Science.gov (United States)

    Makinaga, A.

    2015-10-01

    Nuclear databases are important tools to apply nuclear phenomena to various fields of nuclear engineering. It is now recognized that the databases must be further developed for photo-nuclear reaction data for nuclear security, safety and nonproliferation applications. Hokkaido University Nuclear Reaction Data Centre (JCPRG) has contributed to the Experimental Nuclear Reaction Data Library (EXFOR) which is developed by the International Network of Nuclear Reaction Data Centres under coordination by IAEA. We report here on the recent compilation of the nuclear data files for the photonuclear reaction.

  19. ON THE LATE OCCURRENCE OF DRIFT ICE RETREAT FROM THE HOKKAIDO COAST IN THE 1992/93 SEA ICE SEASON

    OpenAIRE

    トヨタ, タケノブ; カミヒラ, エツロウ; Takenobu, TOYOTA; Etsuro, KAMIHIRA

    1994-01-01

    The 1992/93 sea ice season in the Sea of Okhotsk was characterized by the record-breaking late appearance and late disappearance of drift ice off the Hokkaido coast. The 1992/93 winter season was rather warm and the arrival of drift ice off the Hokkaido coast was a few weeks later than normal. The averaged amount of drift ice in sight at Kitamiesashi, Omu, Mombetsu, and Abashiri was half of normal. Nevertheless the last dates of drift ice at the four observatories were all in early May, about...

  20. Limitations of Radar Coordinates

    OpenAIRE

    Bini, Donato; Lusanna, Luca; Mashhoon, Bahram

    2004-01-01

    The construction of a radar coordinate system about the world line of an observer is discussed. Radar coordinates for a hyperbolic observer as well as a uniformly rotating observer are described in detail. The utility of the notion of radar distance and the admissibility of radar coordinates are investigated. Our results provide a critical assessment of the physical significance of radar coordinates.

  1. Seasonal changes in spermatogenesis and peripheral testosterone concentration in raccoons (Procyon lotor) in Hokkaido.

    Science.gov (United States)

    Okuyama, Minami W; Shimozuru, Michito; Takahashi, Nobuhiro; Fukui, Daisuke; Nakamura, Ryohei; Tsubota, Toshio

    2012-06-01

    Feral raccoons (Procyon lotor) have been increasing in number since 1979 and are currently subject to pest control in Hokkaido. One of the reasons for the increase in numbers is thought to be the high reproductive potential of raccoons, but little is known about their reproduction. The main aim of this study was to clarify seasonal changes in spermatogenesis and peripheral testosterone concentration of raccoons in Hokkaido. In the present study, external characteristics and histology of the testis and epididymis and the plasma testosterone concentration were investigated in 68 feral, male raccoons culled for pest control and once a month in one live, captive male. The feral males exhibited seasonal changes in spermatogenesis, showing active spermatogenesis in autumn, winter and spring (October-June) with noted spermatogenesis and inactive spermatogenesis in summer (July-September) with lower mean levels of spermatozoa in the cauda epididymis. Even in the inactive period, spermatozoa were observed in about half of the individuals (14/26); therefore, individuals producing spermatozoa existed every month throughout the year. Testosterone concentrations were significantly high in the winter mating season. In the captive male, the testosterone concentrations were low from June to August, and spermatozoa could not be observed from July to September. These results suggest that raccoons exhibit seasonality of reproduction, but the time and duration of spermatogenetic decline varies widely among individuals. This individual variation in the inactive period is a feature of male raccoon reproduction and is unique among seasonally breeding mammals.

  2. P wave azimuthal and radial anisotropy of the Hokkaido subduction zone

    Science.gov (United States)

    Niu, Xiongwei; Zhao, Dapeng; Li, Jiabiao; Ruan, Aiguo

    2016-04-01

    We present the first three-dimensional P wave radial anisotropy tomography of the Hokkaido subduction zone, as well as P wave azimuthal anisotropy and S wave tomography, which are determined by inverting 298,430 P wave and 233,934 S wave arrival times from 14,245 local earthquakes recorded by 344 seismic stations. Our results reveal significant velocity heterogeneity, seismic anisotropy, and upwelling flows beneath the study region. In the mantle wedge, prominent low-velocity (low-V) anomalies exhibit trench-normal fast-velocity directions (FVDs) and a negative radial anisotropy (i.e., vertical velocity > horizontal velocity), which may reflect upwelling mantle flows. Fan-shaped FVDs are found at depths of 65-90 km, and a detailed 3-D mantle flow pattern is revealed, which may be caused by a combination of oblique subduction of the Pacific plate and collision of the Kuril arc with the Honshu arc beneath southern Hokkaido. The radial anisotropy changes at ~100 km depth, which may reflect variations in temperature and fluid conditions there. The subducting Pacific slab exhibits a positive radial anisotropy (i.e., horizontal velocity > vertical velocity), which may reflect the original fossil anisotropy when the Pacific plate formed at the mid-ocean ridge.

  3. Nitrogen digestion and urea recycling in Hokkaido native horses fed hay-based diets.

    Science.gov (United States)

    Obitsu, Taketo; Hata, Hiroshi; Taniguchi, Kohzo

    2015-02-01

    Nitrogen (N) digestion and urea-N metabolism in Hokkaido native horses fed roughage-based diets containing different types and levels of protein sources were studied. Horses (173 ± 4.8 kg) fitted with an ileum cannula were fed four diets consisting of 100% timothy hay (TH), 88% TH and 12% soybean meal (SBM), 79% TH and 21% SBM, and 51% TH and 49% alfalfa hay at 2.2% of body weight. Dietary protein content varied from 5% to 15% of dry matter. Apparent N digestibilities in the pre-cecum and total tract for the TH diet were lower than those for other diets. However, the proportion of post-ileum N digestion to N intake was not affected by the diets. Urea-N production was linearly related to N intake, but gut urea-N entry was not affected by the diets. The proportion of gut urea-N entry to urea-N production tended to be higher for the TH diet (57%) than the two SBM diets (39%). Anabolic use of urea-N entering the gut was not affected by the diets (20-36% of gut urea-N entry). These results indicate that urea-N recycling provides additional N sources for microbial fermentation in the hindgut of Hokkaido native horses fed low-quality roughages.

  4. Transcriptome analysis of predator- and prey-induced phenotypic plasticity in the Hokkaido salamander (Hynobius retardatus).

    Science.gov (United States)

    Matsunami, Masatoshi; Kitano, Jun; Kishida, Osamu; Michimae, Hirofumi; Miura, Toru; Nishimura, Kinya

    2015-06-01

    Predator- and prey-induced phenotypic plasticity is widely observed among amphibian species. Although ecological factors inducing diverse phenotypic responses have been extensively characterized, we know little about the molecular bases of variation in phenotypic plasticity. Larvae of the Hokkaido salamander, Hynobius retardatus, exhibit two distinct morphs: the presence of their prey, Rana pirica tadpoles, induces a broad-headed attack morph, and the presence of predatory dragonfly nymphs (Aeshna nigroflava) induces a defence morph with enlarged external gills and a high tail. To compare the genes involved in predator- and prey-induced phenotypic plasticity, we carried out a de novo transcriptome analysis of Hokkaido salamander larvae exposed to either prey or predator individuals. First, we found that the number of genes involved in the expression of the defence morph was approximately five times the number involved in the expression of the attack morph. This result is consistent with the fact that the predator-induced plasticity involves more drastic morphological changes than the prey-induced plasticity. Second, we found that particular sets of genes were upregulated during the induction of both the attack and defence morphs, but others were specific to the expression of one or the other morph. Because both shared and unique molecular mechanisms were used in the expression of each morph, the evolution of a new plastic phenotype might involve both the co-option of pre-existing molecular mechanisms and the acquisition of novel regulatory mechanisms.

  5. RADAR PPI Scope Overlay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — RADAR PPI Scope Overlays are used to position a RADAR image over a station at the correct resolution. The archive maintains several different RADAR resolution types,...

  6. Towards the azimuthal characteristics of ionospheric and seismic effects of "Chelyabinsk" meteorite fall according to the data from coherent radar, GPS and seismic networks

    CERN Document Server

    Berngardt, O I; Kutelev, K A; Zherebtsov, G A; Dobrynina, A A; Shestakov, N V; Zagretdinov, R V; Bakhtiyarov, V F; Kusonsky, O A

    2015-01-01

    We present the results of a study of the azimuthal characteristics of ionospheric and seismic effects of the meteorite 'Chelyabinsk', based on the data from the network of GPS receivers, coherent decameter radar EKB SuperDARN and network of seismic stations. It is shown, that 6-14 minutes after the bolide explosion, GPS network observed the cone-shaped wavefront of TIDs that is interpreted as a ballistic acoustic wave. The typical TIDs propagation velocity were observed 661+/-256m/s, which corresponds to the expected acoustic wave speed for 240km height. 14 minutes after the bolide explosion, at distances of 200km we observed the emergence and propagation of a TID with spherical wavefront, that is interpreted as gravitational mode of internal acoustic waves. The propagation velocity of this TID was 337+/-89m/s which corresponds to the propagation velocity of these waves in similar situations. At EKB SuperDARN radar, we observed TIDs in the sector of azimuthal angles close to the perpendicular to the meteorite...

  7. Advances in bistatic radar

    CERN Document Server

    Willis, Nick

    2007-01-01

    Advances in Bistatic Radar updates and extends bistatic and multistatic radar developments since publication of Willis' Bistatic Radar in 1991. New and recently declassified military applications are documented. Civil applications are detailed including commercial and scientific systems. Leading radar engineers provide expertise to each of these applications. Advances in Bistatic Radar consists of two major sections: Bistatic/Multistatic Radar Systems and Bistatic Clutter and Signal Processing. Starting with a history update, the first section documents the early and now declassified military

  8. Radar-to-Radar Interference Suppression for Distributed Radar Sensor Networks

    OpenAIRE

    Wen-Qin Wang; Huaizong Shao

    2014-01-01

    Radar sensor networks, including bi- and multi-static radars, provide several operational advantages, like reduced vulnerability, good system flexibility and an increased radar cross-section. However, radar-to-radar interference suppression is a major problem in distributed radar sensor networks. In this paper, we present a cross-matched filtering-based radar-to-radar interference suppression algorithm. This algorithm first uses an iterative filtering algorithm to suppress the radar-to-radar ...

  9. LOCAL INITIATIVES FOR SUSTAINABLE DEVELOPMENT IN RURAL HOKKAIDO: A CASE STUDY OF SAMANI

    Directory of Open Access Journals (Sweden)

    Devon Dublin

    2013-01-01

    Full Text Available The paper presents the results of a field investigation about sustainable development of Samani town—a rural area in Hidaka region, Hokkaido, Japan. Local activities, business, environmental, social and economic challenges that affect the town as well as the advantages were investigated. The research was done by means of field visits, questionnaires and interviews involving the local people and government. The main economic sectors: olivine industry, fishery, agriculture and tourism were targeted as well as the government sector and the local high school with a particular focus on rural-urban migration. Samani has quite unique natural features on hand but a few strong comprehensive challenges on the other hand. The authors focused on the citizens opinions and positions which were based on the uniqueness of Samani and their own local activities and initiatives for the sustainable development of the town in the future which can be replicated in other rural communities around the world.

  10. Seasonal and diurnal variability in historical warming due to the urbanization of Hokkaido, Japan

    Science.gov (United States)

    Sugimoto, Shiori; Sato, Tomonori; Sasaki, Tomonori

    2015-06-01

    The influence of historical urbanization on warming trends observed on Hokkaido Island (Japan) is discussed with an emphasis on seasonally and diurnally differential responses of air temperature to urban effects. Two numerical experiments using past and current land use scenarios successfully simulated the observed temperature trends, showing a greater rate of warming in winter than in summer and a greater increase in daily minimum than daily maximum temperatures. The results suggest that seasonal and diurnal variations in the thermal structure of the planetary boundary layer play a leading role in determining the warming rate of surface air. Under strongly stable stratification, anomalous heating within the urban canopy dissipates into a near-surface shallow layer, resulting in increased daily minimum temperatures during winter. In summer, however, anomalous urban heating due to increased Bowen ratios is attenuated by vertical mixing in the convective daytime boundary layer, suppressing the impact of urban heating on surface warming.

  11. High-resolution seismic attenuation structures beneath Hokkaido corner, northeastern Japan

    Science.gov (United States)

    Kita, S.; Nakajima, J.; Okada, T.; Hasegawa, A.; Katsumata, K.; Asano, Y.; Uchida, N.

    2013-12-01

    1. Introduction In the Hokkaido corner, the Kuril fore-arc sliver collides with the northeastern Japan arc. Using data from the nationwide Kiban seismic network and a temporary seismic network, Kita et al. [2012] determined high-resolution 3D seismic velocity structure beneath this area for deeper understanding of the collision process of two fore-arcs. The results show that a broad low-V zone (crust material) anomalously descends into the mantle wedge at depths of 30-90 km in the west of the Hidaka main thrust. On the other hand, several high-velocity zones having velocities of mantle materials are distributed in the crust at depths of 10-35 km. These high-velocity zones are inclined eastward, being nearly parallel to each other. Two of the western boundaries of these high-V zones correspond to the fault planes of the 1970 Mj 6.7 Hidaka and the 1982 Mj 7.1 Urakawa-oki earthquakes, respectively. In this study, we merged waveform data from the Kiban-network and from a dense temporary seismic network [Katsumata et al., 2002], and estimated the seismic attenuation structure to compare with the seismic velocity images of Kita et al. [2012]. 2. Data and method We estimated corner frequency for each earthquake by the spectral ratio method using the coda waves [e.g. Mayeda et al., 2007]. Then, we simultaneously determined values of t* and the amplitude level at lower frequencies from the observed spectra after correcting for the source spectrum. Seismic attenuation (Q-1 value) structure was obtained, inverting t* values with the tomographic code of Zhao et al. [1992]. We adopted the geometry of the Pacific plate which was precisely estimated by Kita et al. [2010b]. The study region covers an area of 41-45N, 140.5-146E, and a depth range of 0-200 km. We obtained 131,958 t* from 6,186 events (M>2.5) that occurred during the period from Aug. 1999 to Dec. 2012. The number of stations used is 353. Horizontal and vertical grid nodes were set with spacing of 0.10-0.3 degree and

  12. My Vision in Teaching at Health Sciences University of Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    Satomi Kondo

    2003-11-01

    Full Text Available This spring, I returned to my home country after eleven years of living in Vancouver, Canada. I worked as a music therapist at an acute care hospital and experienced music therapy to be a very important means to integrate cure and care in a medical setting. With my ever growing passion and wonder over the power of music, I now work at Health Sciences University of Hokkaido teaching the potency of music to a variety of health care students. I would like to share my experiences and in part some of the characteristics of this particular university that strive for new ideas of health sciences on the basis of integration of cure and care.

  13. Applying ICESat/GLAS data to estimate forest aboveground biomass on Hokkaido, Japan

    Science.gov (United States)

    Hayashi, M.; Saigusa, N.; Oguma, H.; Yamao, Y.; Yamagata, Y.; Takao, G.

    2013-12-01

    Spaceborne Light Detection And Ranging (LiDAR) has an ability to measure forest resources with high accuracy, therefore, it will contribute to evaluating global carbon cycle or addressing climate change. We then evaluated the potential of spaceborne LiDAR to measure forest resources, and used Geoscience Laser Altimeter System (GLAS) data obtained with the Ice, Cloud, and land Elevation Satellite (ICESat) to develop an estimation methodology for forest biomass. The study area was the island of Hokkaido, Japan. We compared two estimation methods: (i) a direct method that uses some of the GLAS waveform parameters to estimate aboveground biomass (AGB) directly, and (ii) an allometric method that uses an allometric equation to estimate AGB from the canopy height estimated from the GLAS waveform. We used two kinds of ground truth data: (i) field survey data in situ measurements of AGB by the Bitterlich method at 106 points within GLAS footprints, and (ii) airborne LiDAR data from maximum canopy height measurements at 481 points within GLAS footprints. We then used the field survey data to develop the AGB estimation equation of the direct method by carrying out a multiple regression analysis that related GLAS waveform parameters to AGB. For the allometric method, we also carried out a multiple regression analysis using the airborne LiDAR data to estimate canopy height from GLAS data. Two parameters were used as the explanatory variables: a 'terrain index' calculated from the ground elevation difference within a GLAS footprint, and a 'GLAS waveform extent'. The root mean square error (RMSE) of the canopy height estimates was 4.1 m. We used the allometric equation determined from the field survey data to relate canopy height to AGB and then estimated the AGB from the GLAS estimates of canopy height. The accuracy of the AGB estimates obtained by these two estimation methods was determined by comparison with the field survey data. The RMSEs of the direct and allometric

  14. Genetic and antigenic characterization of bovine viral diarrhea viruses isolated from cattle in Hokkaido, Japan.

    Science.gov (United States)

    Abe, Yuri; Tamura, Tomokazu; Torii, Shiho; Wakamori, Shiho; Nagai, Makoto; Mitsuhashi, Kazuya; Mine, Junki; Fujimoto, Yuri; Nagashima, Naofumi; Yoshino, Fumi; Sugita, Yukihiko; Nomura, Takushi; Okamatsu, Masatoshi; Kida, Hiroshi; Sakoda, Yoshihiro

    2016-01-01

    In our previous study, we genetically analyzed bovine viral diarrhea viruses (BVDVs) isolated from 2000 to 2006 in Japan and reported that subgenotype 1b viruses were predominant. In the present study, 766 BVDVs isolated from 2006 to 2014 in Hokkaido, Japan, were genetically analyzed to understand recent epidemics. Phylogenetic analysis based on nucleotide sequences of the 5'-untranslated region of viral genome revealed that 766 isolates were classified as genotype 1 (BVDV-1; 544 isolates) and genotype 2 (BVDV-2; 222). BVDV-1 isolates were further divided into BVDV-1a (93), 1b (371) and 1c (80) subgenotypes, and all BVDV-2 isolates were grouped into BVDV-2a subgenotype (222). Further comparative analysis was performed with BVDV-1a, 1b and 2a viruses isolated from 2001 to 2014. Phylogenetic analysis based on nucleotide sequences of the viral glycoprotein E2 gene, a major target of neutralizing antibodies, revealed that BVDV-1a, 1b and 2a isolates were further classified into several clusters. Cross-neutralization tests showed that BVDV-1b isolates were antigenically different from BVDV-1a isolates, and almost BVDV-1a, 1b and 2a isolates were antigenically similar among each subgenotype and each E2 cluster. Taken together, BVDV-1b viruses are still predominant, and BVDV-2a viruses have increased recently in Hokkaido, Japan. Field isolates of BVDV-1a, 1b and 2a show genetic diversity on the E2 gene with antigenic conservation among each subgenotype during the last 14 years.

  15. Application of tritium in precipitation and baseflow in Japan: a case study of groundwater transit times and storage in Hokkaido watersheds

    OpenAIRE

    Gusyev, Maksym A.; Morgenstern, Uwe; Stewart, Michael K.; Yamazaki, Yusuke; Kashiwaya, Kazuhisa; Nishihara, Terumasa; Kuribayashi, Daisuke; Sawano, Hisaya; Iwami, Yoichi

    2016-01-01

    In this study, we demonstrate the application of tritium in precipitation and baseflow to estimate groundwater transit times and storage volumes in Hokkaido, Japan. To establish the long-term history of tritium concentration in Japanese precipitation, we used tritium data from the global network of isotopes in precipitation and from local studies in Japan. The record developed for Tokyo area precipitation was scaled for Hokkaido using tritium values for precipitation based o...

  16. Adaptive radar resource management

    CERN Document Server

    Moo, Peter

    2015-01-01

    Radar Resource Management (RRM) is vital for optimizing the performance of modern phased array radars, which are the primary sensor for aircraft, ships, and land platforms. Adaptive Radar Resource Management gives an introduction to radar resource management (RRM), presenting a clear overview of different approaches and techniques, making it very suitable for radar practitioners and researchers in industry and universities. Coverage includes: RRM's role in optimizing the performance of modern phased array radars The advantages of adaptivity in implementing RRMThe role that modelling and

  17. Radar and ARPA manual

    CERN Document Server

    Bole, A G

    2013-01-01

    Radar and ARPA Manual focuses on the theoretical and practical aspects of electronic navigation. The manual first discusses basic radar principles, including principles of range and bearing measurements and picture orientation and presentation. The text then looks at the operational principles of radar systems. Function of units; aerial, receiver, and display principles; transmitter principles; and sitting of units on board ships are discussed. The book also describes target detection, Automatic Radar Plotting Aids (ARPA), and operational controls of radar systems, and then discusses radar plo

  18. Accumulation properties of inorganic mercury and organic mercury in the red-crowned crane Grus japonensis in east Hokkaido, Japan.

    Science.gov (United States)

    Teraoka, Hiroki; Okamoto, Erika; Kudo, Moe; Nakayama, Shouta M M; Ikenaka, Yoshinori; Ishizuka, Mayumi; Endo, Tetsuya; Kitazawa, Takio; Hiraga, Takeo

    2015-12-01

    The red-crowned (Japanese) crane Grus japonensis is native to east Hokkaido, Japan, in contrast to the East Asia mainland. Previously, we reported that red-crowned cranes in Hokkaido were highly contaminated with mercury in the 1990s and that the contamination rapidly decreased to a moderate level in the 2000s. In the present study, we determined levels of organic mercury (O-Hg) in the liver and kidney of cranes in east Hokkaido in comparison with levels of total mercury (T-Hg). T-Hg levels in the kidneys were higher than those in the livers in adults but not in subadults and juveniles; however, the reverse was the case for O-Hg even for adults. The ratio of O-Hg to T-Hg in both the liver and kidney decreased as T-Hg increased in the three developmental stages. While the ratios of O-Hg to T-Hg in the liver and kidney of adults were significantly lower than those of juveniles, the ratios were similar for adults and juveniles in a lower range of T-Hg. The ratio of selenium (Se) to T-Hg decreased as T-Hg increased in both the liver and kidney, irrespective of stages. Mercury burdens in feathers were about 59% and 67% of the total body burdens for juveniles and adults, respectively. Furthermore, ratios of carbon and nitrogen stable isotopes to T-Hg varied greatly, with no relation to mercury level in the liver. The results suggest slow accumulation of inorganic mercury in the kidney of red-crowned cranes in east Hokkaido, Japan.

  19. Shallow repeating slow-slip-events along the convergent block boundary in northern Hokkaido, Japan

    Science.gov (United States)

    Ikeda, S.; Heki, K.; Kimura, T.

    2015-12-01

    The Japanese Islands are divided into several crustal blocks [e.g. Loveless and Meade, 2010 JGR]. In the Northern Hokkaido, the boundary between the Amurian and the North American Plates run north-south between 44.0N and 45.4N. The east-west block convergence is considered to be as fast as ~1 cm/year there, but few large earthquakes are known to have occurred along this boundary. Recently, a slow slip event (SSE) is reported to have occurred in a segment at ~45.0N over a 4 months period from 2012 summer to the early 2013 [Ohzono et al., 2014 GJI]. The maximum surface movements was about 15 mm, and the moment magnitude of the SSE would not exceed 6.0 (fault slip is estimated as 10 cm). This suggests that plate convergence takes place as episodic SSEs in this block boundary. In this research, we looked for signatures of repeating SSEs along this block boundary using continuous GNSS data of the dense array GEONET in Japan. In order to detect faint signatures of SSEs in the coordinate time series, we adopted the method using AIC (Akaike's Information Criterion) similar to Nishimura et al. [2013 JGR] and Nishimura [2014 PEPS]. As a result, we were able to find numbers of SSE signals in various segments along the boundary. The detected SSEs are all fairly small, and surface movements did not exceed a few millimeters (except the 2012-2013 SSE reported in Ohzono et al. [2014]). We also searched earthquakes that may have triggered these SSEs. Although the 2012 SSE seems to have been triggered by a deep earthquake beneath Sakhalin on Aug. 14, 2012, no clear triggering earthquakes were identified for other SSEs. SSEs in subduction zones are known to recur fairly regularly, e.g. biannually repeating SSE in the SW part of the Ryukyu Arc [Heki and Kataoka, 2008 JGR]. However, shallow SSEs along the block boundary in the northern Hokkaido did not show such regular occurrences. We plan to confirm these SSE occurrences by comparing GNSS data with the Hi-Net tiltmeter records.

  20. Magnetotelluric Study on the Donan Geothermal Field, Southern Part of Hokkaido, Japan

    Science.gov (United States)

    Hayakawa, M.; Mogi, T.

    2016-12-01

    We performed a MT study in the Donan geothermal field where deep seated hot granitic rocks are distributing as a source of geothermal resources. But no prominent fracture zone were found in this area. Imaging a fracture zone and clarifying geothermal reservoirs are purpose of the study. Quaternary volcanoes, such as Hokkaido Komagatake and Esan in the southern part, and Karibayama in the northern part, are situated in the surroundings of the Donan area, southwestern Hokkaido, Japan. Even though recent volcanic activity is not seen in the central part, geothermal gradient is high. The geological structure of this region is dominated by the movement of basement blocks aligning in the north-south, and folds and fractures have developed. Many hot springs and geothermal manifestations are seen in this region where called "Yakumo-Nigorikawa geothermal zone." The Mori geothermal power plant, located at south area, is operating in the Nigorikawa caldera formed about 12,000 years ago. Like Nigorikawa, the Yakumo area, located at the central part of the Donan area, have been thought as promising geothermal area, and many geothermal study were performed in the 1990th. Six drilling holes were excavated and they showed that hot granitic rock are distributing at around below 1000m depth, and temperature is higher than 200 degrees in this area. We carried out new magnetotelluric (MT) survey at 20 stations in the Yakumo area. We constructed 2-D and 3-D resistivity model with MT data. Because the anomalous phases exceeding 90 degree were seen in some sites at frequency less than 0.1Hz, we only used the data at frequency range of 320Hz and 0.1Hz in this study. We used Ogawa and Uchida (1996) as a 2D inversion and Han et al. (2008) that have applied approximate sensitivity, as 3D inversion respectively. From the resistivity models, the remarkable low resistivity zone extending from deep to shallower is seen at the center of the survey area, that is inclined from south to north. A

  1. Principles of modern radar systems

    CERN Document Server

    Carpentier, Michel H

    1988-01-01

    Introduction to random functions ; signal and noise : the ideal receiver ; performance of radar systems equipped with ideal receivers ; analysis of the operating principles of some types of radar ; behavior of real targets, fluctuation of targets ; angle measurement using radar ; data processing of radar information, radar coverage ; applications to electronic scanning antennas to radar ; introduction to Hilbert spaces.

  2. Passive MIMO Radar Detection

    Science.gov (United States)

    2013-09-01

    cumulative distribution function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 CORA COvert RAdar...PaRaDe), developed by the Insti- tute of Electronic Systems at the Warsaw University of Technology [59, 60]; COvert RAdar ( CORA ), developed by the German

  3. Weather Radar Impact Zones

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent an inventory of the national impacts of wind turbine interference with NEXRAD radar stations. This inventory was developed by the NOAA Radar...

  4. Digital LPI Radar Detector

    OpenAIRE

    Ong, Peng Ghee; Teng, Haw Kiad

    2001-01-01

    Approved for public release; distribution is unlimited The function of a Low Probability ofIntercept (LPI) radar is to prevent its interception by an Electronic Support (ES) receiver. This objective is generally achieved through the use of a radar waveform that is mismatched to those waveforms for which an ES receiver is tuned. This allows the radar to achieve a processing gain, with respect to the ES receiver, that is equal to the time-bandwidth product ofthe radar waveform. This...

  5. Network radar countermeasure systems integrating radar and radar countermeasures

    CERN Document Server

    Jiang, Qiuxi

    2016-01-01

    This is the very first book to present the network radar countermeasure system. It explains in detail the systematic concept of combining radar and radar countermeasures from the perspective of the information acquisition of target location, the optimization of the reconnaissance and detection, the integrated attack of the signals and facilities, and technological and legal developments concerning the networked system. It achieves the integration of the initiative and passivity, detection and jamming. The book explains how the system locates targets, completes target identification, tracks targets and compiles the data.

  6. Deep Stochastic Radar Models

    OpenAIRE

    Wheeler, Tim Allan; Holder, Martin; Winner, Hermann; Kochenderfer, Mykel

    2017-01-01

    Accurate simulation and validation of advanced driver assistance systems requires accurate sensor models. Modeling automotive radar is complicated by effects such as multipath reflections, interference, reflective surfaces, discrete cells, and attenuation. Detailed radar simulations based on physical principles exist but are computationally intractable for realistic automotive scenes. This paper describes a methodology for the construction of stochastic automotive radar models based on deep l...

  7. Radar: Human Safety Net

    Science.gov (United States)

    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…

  8. Radar and wind turbines; Radar en windturbines

    Energy Technology Data Exchange (ETDEWEB)

    Van Doorn, H.

    2010-03-15

    In the last years the developments of wind parks were hampered because of their possible effect on the radar for observation of air traffic. Work is currently being done on a new assessment model for wind turbines under the auspices of the steering group National Security for the military radar systems. Air traffic control Netherlands (LVNL) will look at the options for civil radars to join in. [Dutch] In de afgelopen jaren zijn windparkontwikkelingen onder meer belemmerd vanwege mogelijke effecten op radar voor de waarneming van luchtverkeer. Onder auspicien van de stuurgroep Nationale Veiligheid voor de militaire radarsystemen op land wordt gewerkt aan een nieuw beoordelingsmodel voor windturbines. De Luchtverkeersleiding Nederland (LVNL) zal bezien in hoeverre de civiele radars hierbij kunnen aansluiten.

  9. Multifidelity Sparse-Grid-Based Uncertainty Quantification for the Hokkaido Nansei-oki Tsunami

    Science.gov (United States)

    de Baar, Jouke H. S.; Roberts, Stephen G.

    2017-08-01

    With uncertainty quantification, we aim to efficiently propagate the uncertainties in the input parameters of a computer simulation, in order to obtain a probability distribution of its output. In this work, we use multi-fidelity sparse grid interpolation to propagate the uncertainty in the shape of the incoming wave for the Okushiri test-case, which is a wave tank model of a part of the 1993 Hokkaido Nansei-oki tsunami. An important issue with many uncertainty quantification approaches is the `curse of dimensionality': the overall computational cost of the uncertainty propagation increases rapidly when we increase the number of uncertain input parameters. We aim to mitigate the curse of dimensionality by using a multifidelity approach. In the multifidelity approach, we combine results from a small number of accurate and expensive high-fidelity simulations with a large number of less accurate but also less expensive low-fidelity simulations. For the Okushiri test-case, we find an improved scaling when we increase the number of uncertain input parameters. This results in a significant reduction of the overall computational cost. For example, for four uncertain input parameters, accurate uncertainty quantification based on only high-fidelity simulations comes at a normalised cost of 219 high-fidelity simulations; when we use a multifidelity approach, this is reduced to a normalised cost of only 10 high-fidelity simulations.

  10. Persistent organic pollutants in red-crowned cranes (Grus japonensis) from Hokkaido, Japan.

    Science.gov (United States)

    Kakimoto, Kensaku; Akutsu, Kazuhiko; Nagayoshi, Haruna; Konishi, Yoshimasa; Kajimura, Keiji; Tsukue, Naomi; Yoshino, Tomoo; Matsumoto, Fumio; Nakano, Takeshi; Tang, Ning; Hayakawa, Kazuichi; Toriba, Akira

    2017-09-01

    The red-crowned crane (Grus japonensis) from eastern Hokkaido is classified as a Special Natural Monument in Japan. In this study, we determined the concentrations of persistent organic pollutants (POPs) in red-crowned crane muscle tissues (n = 47). Polychlorinated biphenyls (PCBs) had the highest median concentration (240ng/g lipid weight), followed by dichlorodiphenyltrichloroethane and its metabolites (DDTs) (150ng/g lipid weight), chlordane-related compounds (CHLs) (36ng/g lipid weight), hexachlorobenzene (HCB) (16ng/g lipid weight), hexachlorocyclohexanes (HCHs) (4.4ng/g lipid weight), polybrominated diphenyl ethers (PBDEs) (1.8ng/g lipid weight), and finally, Mirex (1.5ng/g lipid weight). Additionally, a positive correlation was found among POP concentrations. No sex differences beyond body parameters were observed. Additionally, red-crowned cranes exhibited a high enantiomeric excess of (+)-alpha-HCH, with enantiomer fractions varying from 0.51 to 0.87 (average: 0.69). Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Molecular survey of Anaplasma and Ehrlichia infections of feral raccoons (Procyon lotor) in Hokkaido, Japan.

    Science.gov (United States)

    Sashika, Mariko; Abe, Go; Matsumoto, Kotaro; Inokuma, Hisashi

    2011-04-01

    Infection by Anaplasma and Ehrlichia in feral raccoons (Procyon lotor) in Hokkaido, Japan, was examined by molecular methods. A polymerase chain reaction (PCR) screen for Anaplasmataceae, based on 16S rRNA, showed that 38 (5.4%) of 699 raccoons examined were positive. These 38 positive samples were examined for Anaplasma phagocytophilum, Anaplasma bovis, Ehrlichia chaffeensis, and Ehrlichia canis infection by species-specific nested PCR. Nested PCR results indicated that 36 of the 38 samples were positive for A. bovis. All 38 samples were PCR negative for A. phagocytophilum, E. chaffeensis, and E. canis. This is the first report of the detection of A. bovis in the peripheral blood of raccoons. A total of 124 raccoons were infested with ticks, including Ixodes ovatus, Ixodes persulcatus, and Haemaphysalis spp. The rate of A. bovis infection in raccoons infested with Haemaphysalis spp. (46.7%, 7/15) was significantly higher than that in raccoons without Haemaphysalis spp. infestation (3.7%, 4/109, p raccoons infested with I. ovatus or I. persulcatus and those not so infested. A total of four ticks (two males and two nymphs) and one larval pools from four raccoons showed positive for A. bovis-specific nested PCR. This results support the correlation between the A. bovis infection of raccoons and Haemaphysalis infestation. In conclusion, raccoons could be possible reservoir animals for A. bovis, and A. bovis infection in raccoons may be related to infestation with Haemaphysalis spp.

  12. Endogenous growth of a Miocene submarine dacite cryptodome, Rebun Island, Hokkaido, Japan

    Science.gov (United States)

    Goto, Yoshihiko; McPhie, Jocelyn

    1998-09-01

    Momo-iwa, Rebun Island, Hokkaido, Japan, is a dacite cryptodome 200-300 m across and 190 m high. The dome is inferred to have intruded wet, poorly consolidated sediment in a shallow marine environment. The internal structure of the dome is concentric, with a massive core, banded rim, and narrow brecciated border, all of which are composed of compositionally uniform feldspar-phyric dacite. Boundaries between each of the zones are distinct but gradational. The massive core consists of homogeneous coherent (unfractured) dacite and is characterized by radial columnar joints 60-200 cm across. The banded rim encircles the massive core and is 40 m wide. It is characterized by large-scale flow banding parallel to the dome surface. The flow banding comprises alternating partly crystalline and more glassy bands 80-150 cm thick. The outermost brecciated border is up to 80 cm thick, and consists of in situ breccia and blocky peperite. The in situ breccia comprises polyhedral dacite clasts 5-20 cm across and a cogenetic granular matrix. The blocky peperite consists of polyhedral dacite clasts 0.5-2 cm across separated by the host sediment (mudstone). The internal structures of the dome suggest endogenous growth involving a continuous magma supply during a single intrusive phase and simple expansion from the interior. Although much larger, the internal structures of Momo-iwa closely resemble those of lobes in subaqueous felsic lobe-hyaloclastite lavas.

  13. Object-Based Analysis and Change Detection of Paddy Field at Hokkaido, Japan

    Science.gov (United States)

    PARK, J.; Kim, Y.; Kwak, Y.

    2015-12-01

    Remote sensing technology has been used in land use and land cover classification. Especially paddy fields is an important cultivated area in Asia. To accurately extract the area is the important indicator to estimate the food production. In this research paddy fields classification in Hokkaido was performed using Topographical features (DEM), Climatic features (accumulated temperature), Spectrometer features (MODIS). Fig. 1. shows the overview of the analysis methods of this research. The process of this research is carried out in 3 steps.1. Determine the accumulated temperature by retrieving the temperature data from the AMeDAS data. 2. Extract the river from the DEM. Set the elevation of the river to 0 to seek the land elevation around it relatively. 3. Calculate the WI (Water Index) using MODIS band 4(Green)and Band 2(NIR). Time series NDVI has been corrected by the FFT method (use a low-pass filter). Phenology information was extracted such as vegetation Onset time, Max value and Duration. Result of the classification was compared with the current vegetation map of the Ministry of the Environment. As a result we can confirm that existence of vegetation map around Sapporo and Asahikawa is almost same. but around Obihiro it was clear that overestimate by water index.

  14. Estimating eroded soil and predicting further erosion in Daisetsuzan National Park in Hokkaido, Japan

    Science.gov (United States)

    Kobayashi, Yusuke; Watanabe, Teiji

    2017-04-01

    This study has three objectives: (1) to estimate changes of the eroded volume of mountain trails from 2014 to 2016 by making DSMs, (2) to understand a relationship between the trail erosion and micro-topography, and (3) to predict the volume of soil that can be eroded in future. Trail erosion has been investigated near Mt. Hokkai-dake in Daisetzuzan National Park, Hokkaido, northern Japan, with a drone (UAV) from 2014 to 2016. Seven segments with the soil erosion from starting sites to ending sites were selected to make DSMs and Orthophotographs by Agisoft, which is one of the Structure from Motion (SfM) software. Then, at fourteen points in each of the seven segments were selected to estimate the volume of soil that can be eroded in the future by PANDA2, a soil compaction penetrometer. The eroded volume in the segment with the largest eroded value attained 274.67 m3 for the two-year period although extremely heavy rain hit this area in the 2016 summer. The result obtained by PANDA2 shows that soil more than 100 cm in depth will be potentially eroded at four points in three years to one hundred years.

  15. Pulse Doppler radar

    CERN Document Server

    Alabaster, Clive

    2012-01-01

    This book is a practitioner's guide to all aspects of pulse Doppler radar. It concentrates on airborne military radar systems since they are the most used, most complex, and most interesting of the pulse Doppler radars; however, ground-based and non-military systems are also included. It covers the fundamental science, signal processing, hardware issues, systems design and case studies of typical systems. It will be a useful resource for engineers of all types (hardware, software and systems), academics, post-graduate students, scientists in radar and radar electronic warfare sectors and milit

  16. Understanding radar systems

    CERN Document Server

    Kingsley, Simon

    1999-01-01

    What is radar? What systems are currently in use? How do they work? This book provides engineers and scientists with answers to these critical questions, focusing on actual radar systems in use today. It is a perfect resource for those just entering the field, or as a quick refresher for experienced practitioners. The book leads readers through the specialized language and calculations that comprise the complex world of radar engineering as seen in dozens of state-of-the-art radar systems. An easy to read, wide ranging guide to the world of modern radar systems.

  17. Multidimensional radar picture

    Science.gov (United States)

    Waz, Mariusz

    2010-05-01

    In marine navigation systems, the three-dimensional (3D) visualization is often and often used. Echosonders and sonars working in hydroacustic systems can present pictures in three dimensions. Currently, vector maps also offer 3D presentation. This presentation is used in aviation and underwater navigation. In the nearest future three-dimensional presentation may be obligatory presentation in displays of navigation systems. A part of these systems work with radar and communicates with it transmitting data in a digital form. 3D presentation of radar picture require a new technology to develop. In the first step it is necessary to compile digital form of radar signal. The modern navigation radar do not present data in three-dimensional form. Progress in technology of digital signal processing make it possible to create multidimensional radar pictures. For instance, the RSC (Radar Scan Converter) - digital radar picture recording and transforming tool can be used to create new picture online. Using RSC and techniques of modern computer graphics multidimensional radar pictures can be generated. The radar pictures mentioned should be readable for ECDIS. The paper presents a method for generating multidimensional radar picture from original signal coming from radar receiver.

  18. Rb-Sr geochronological study on Tatehira granodiorite, Oshima Peninsula, Southwest Hokkaido, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Iizumi, Shigeru; Kobayashi, Hideo; Toyoda, Minoru

    1984-10-01

    It has been known that Tatehira granodiorite, a pluton which occurs sporadically in the southwest region of Hokkaido, is related with Kanoite formation. The radiometric age of this granodiorite still remains unknown. The Tatehira granodiorite intrudes into late Paleozoic or early Mesozoic Matsumae group, and is overlain by Miocene Usubetsu formation unconformably. It occurs as several separated small plutons. The samples for Rb-Sr analysis were collected from one of the plutons in southern part. The determination of the isochron age of rock-minerals and the initial Sr isotopic ratio of Tatehira granodiorite were carried out. This granodiorite is able to be classified into two phases, namely melanocratic (WRM) and leucocratic (WRL) phases. The samples of WRM and WRL were powdered and subjected to X-ray analysis. It was found that the chemical compositions were similar except slight differences in FeO + Fe2O3, CaO and K2O. The Sr isotopic ratio was determined with a MAT 261 mass spectrometer, and the results were analyzed statistically. The Rb and Sr concentrations and the Sr isotopic ratio of WRM, WRL, and PRF (plagio-clase rich fraction) and BRF (biotite rich fraction) separated from the WRL were determined, and the age of 102.5 +- 0.3 Ma and the initial ratio of 0.70538 +- 0.00001 were obtained. The ratio of Tatehira granodiorite is comparable to that of Okushiri Island. Comparing with the data obtained from other region, the granodiorites of Tatehira and Okushiri Island should be related with the granitoids of Abukuma granite province.

  19. Formation processes of the 1909 Tarumai and the 1944 Usu lava domesin Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    I. Yokoyama

    2004-06-01

    Full Text Available The formation of the two particular lava domes in Hokkaido, Japan is described and interpreted mainly from geophysical viewpoints. The 1909 eruption of Tarumai volcano was not violent but produced a lava dome over four days. The growth rate of the dome is discussed under the assumption that the lava flow was viscous and plastic fluid during its effusion. By Hagen-Poiseuille?s Law, the length of the conduit of the lava dome is rather ambiguously determined as a function of viscosity of the magma and diameter of the conduit. The 1944 Usu dome extruded as a parasitic cone of Usu volcano, not in the crater, but in a flat cornfield at the foot of the volcano. From the beginning to the end for more than 17 months, seismometric and geodetic observations of the dome activity were carried out by several pioneering geophysicists. Utilizing their data, pseudo growth curves of the dome at each stage can be drawn. The lava ascended rather uniformly, causing uplift of the ground surface until half-solidified lava reached the surface six months after the deformation began. Thereafter, the lava dome added lateral displacements and finally achieved its onion structure. These two lava domes are of contrasting character, one is andesitic and formed quickly while the other is dacitic and formed slowly, but both of them behaved as viscous and plastic flows during effusion. It is concluded that both the lava domes formed by uplift of magma forced to flow through the conduits, analogous to squeezing toothpaste out of a tube.

  20. Net ecosystem CO{sub 2} exchange over a larch forest in Hokkaido, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Huimin Wang; Saigusa, Nobuko; Yamamoto, Susumu; Kondo, Hiroaki [National Inst. of Advanced Industrial Science and Technology, Tsukuba Science City (Japan); Hirano, Takashi [Hokkaido Univ., Sapporo (Japan); Toriyama, Atsushi; Fujinuma, Yasumi [National Inst. for Environmental Studies, Tsukuba (Japan)

    2004-12-01

    Larch forests are distributed extensively in the east Eurasian continent and are expected to play a significant role in the terrestrial ecosystem carbon cycling process. In view of the fact that studies on carbon exchange for this important biome have been very limited, we have initiated a long-term flux observation in a larch forest ecosystem in Hokkaido in northern Japan since 2000. The net ecosystem CO{sub 2} exchange (NEE) showed large seasonal and diurnal variation. Generally, the larch forest ecosystem released CO{sub 2} in nighttime and assimilated CO{sub 2} in daytime during the growing season from May to October. The ecosystem started to become a net carbon sink in May, reaching a maximum carbon uptake as high as 186 g C m{sup -2} month{sup -1} in June. With the yellowing, senescing and leaf fall, the ecosystem turned into a carbon source in November. During the non-growing season, the larch forest ecosystem became a net source of CO{sub 2}, releasing an average of 16.7 g C m{sup -2} month{sup -1}. Overall, the ecosystem sequestered 141-240 g C m{sup -2} yr{sup -1} in 2001. The NEE was significantly influenced by environmental factors. Respiration of the ecosystem, for example, was exponentially dependent on air temperature, while photosynthesis was related to the incident PAR in a manner consistent with the Michaelis-Menten model. Although the vapor pressure deficit (VPD) was scarcely higher than 15 hPa, the CO{sub 2} uptake rate was also depressed when VPD surpassed 10 hPa (Author)

  1. Net ecosystem CO 2 exchange over a larch forest in Hokkaido, Japan

    Science.gov (United States)

    Wang, Huimin; Saigusa, Nobuko; Yamamoto, Susumu; Kondo, Hiroaki; Hirano, Takashi; Toriyama, Atsushi; Fujinuma, Yasumi

    Larch forests are distributed extensively in the east Eurasian continent and are expected to play a significant role in the terrestrial ecosystem carbon cycling process. In view of the fact that studies on carbon exchange for this important biome have been very limited, we have initiated a long-term flux observation in a larch forest ecosystem in Hokkaido in northern Japan since 2000. The net ecosystem CO 2 exchange (NEE) showed large seasonal and diurnal variation. Generally, the larch forest ecosystem released CO 2 in nighttime and assimilated CO 2 in daytime during the growing season from May to October. The ecosystem started to become a net carbon sink in May, reaching a maximum carbon uptake as high as 186 g C m -2 month -1 in June. With the yellowing, senescing and leaf fall, the ecosystem turned into a carbon source in November. During the non-growing season, the larch forest ecosystem became a net source of CO 2, releasing an average of 16.7 g C m -2 month -1. Overall, the ecosystem sequestered 141-240 g C m -2 yr -1 in 2001. The NEE was significantly influenced by environmental factors. Respiration of the ecosystem, for example, was exponentially dependent on air temperature, while photosynthesis was related to the incident PAR in a manner consistent with the Michaelis-Menten model. Although the vapor pressure deficit (VPD) was scarcely higher than 15 hPa, the CO 2 uptake rate was also depressed when VPD surpassed 10 hPa.

  2. Upper Boundary of the Pacific Plate Subducting Under Hokkaido,Japan,Estimated from ScSp Phase

    OpenAIRE

    長田, 絹絵; 吉澤, 和範; 蓬田, 清

    2006-01-01

    Geometry of the upper boundary of the subducting Pacific plate or slab was estimated in the Hokkaido region, Japan, using the ScSp phase: the converted phase to P wave at the boundary from the S wave reflected at the core-mantle boundary and propagating nearly vertically (i.e., ScS phase). Taking the advantage of a dense seismic network named “Hi-net” recently deployed across the Japanese islands, we applied several seismic array analyses to the recorded waveform data for a large nearby deep ...

  3. Contamination status and accumulation characteristics of metals and a metalloid in birds on Teuri Island, Hokkaido, Japan.

    Science.gov (United States)

    Ishii, Chihiro; Ikenaka, Yoshinori; Nakayama, Shouta M M; Suzuki, Yuya; Watanuki, Yutaka; Watanabe, Yuji; Yohannes, Yared Beyene; Mizukawa, Hazuki; Ishizuka, Mayumi

    2014-08-01

    Teuri Island, Hokkaido in Japan is an important place for seabirds breeding. We measured the concentrations of heavy metals (Hg, Cd, Cr, Co, Ni, Cu, Zn, and Pb) and a metalloid (As) in rhinoceros auklet (Cerorhinca monocerata) (n = 7), thick-billed murre (Uria lomvia) (n = 2), spectacled guillemot (Cepphus carbo) (n = 6), slaty-backed gull (Larus schistisagus) (n = 15), jungle crow (Corvus macrorhynchos) (n = 3), Japanese anchovy (Engraulis japonica) (n = 6) and Atka mackerel (Pleurogrammus azonus) (n = 2). Spectacled guillemot had high As concentrations, with its source being their feeding habitat. Concentration of Hg in kidney of jungle crow was higher than other seabird species at Teuri.

  4. Phased-array radar design application of radar fundamentals

    CERN Document Server

    Jeffrey, Thomas

    2009-01-01

    Phased-Array Radar Design is a text-reference designed for electrical engineering graduate students in colleges and universities as well as for corporate in-house training programs for radar design engineers, especially systems engineers and analysts who would like to gain hands-on, practical knowledge and skills in radar design fundamentals, advanced radar concepts, trade-offs for radar design and radar performance analysis.

  5. Radar Signature Calculation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The calculation, analysis, and visualization of the spatially extended radar signatures of complex objects such as ships in a sea multipath environment and...

  6. Doppler radar physiological sensing

    CERN Document Server

    Lubecke, Victor M; Droitcour, Amy D; Park, Byung-Kwon; Singh, Aditya

    2016-01-01

    Presents a comprehensive description of the theory and practical implementation of Doppler radar-based physiological monitoring. This book includes an overview of current physiological monitoring techniques and explains the fundamental technology used in remote non-contact monitoring methods. Basic radio wave propagation and radar principles are introduced along with the fundamentals of physiological motion and measurement. Specific design and implementation considerations for physiological monitoring radar systems are then discussed in detail. The authors address current research and commercial development of Doppler radar based physiological monitoring for healthcare and other applications.

  7. Combined radar and telemetry system

    Energy Technology Data Exchange (ETDEWEB)

    Rodenbeck, Christopher T.; Young, Derek; Chou, Tina; Hsieh, Lung-Hwa; Conover, Kurt; Heintzleman, Richard

    2017-08-01

    A combined radar and telemetry system is described. The combined radar and telemetry system includes a processing unit that executes instructions, where the instructions define a radar waveform and a telemetry waveform. The processor outputs a digital baseband signal based upon the instructions, where the digital baseband signal is based upon the radar waveform and the telemetry waveform. A radar and telemetry circuit transmits, simultaneously, a radar signal and telemetry signal based upon the digital baseband signal.

  8. Timing of puberty and its relationship with body growth and season in male raccoons (Procyon lotor) in Hokkaido.

    Science.gov (United States)

    Okuyama, Minami W; Shimozuru, Michito; Abe, Go; Nakai, Mariko; Sashika, Mariko; Shimada, Ken-Ichiro; Takahashi, Nobuhiro; Fukui, Daisuke; Nakamura, Ryohei; Tsubota, Toshio

    2013-01-01

    The raccoon (Procyon lotor), indigenous to North America, has naturalized in Japan as an invasive alien species, having been introduced into the country in the 1970s. In Hokkaido, the northernmost island of Japan, feral raccoons have been increasing in number and spreading throughout the island. The age at the onset of puberty for raccoons is important for estimating individual lifetime reproductive success and population growth. The present study investigated the timing of and potential factors affecting the onset of puberty in male raccoons in Hokkaido. External characteristics and histology of testes were studied in 151 male feral raccoons and in 1 captive juvenile. For the majority of feral yearling raccoons, prepubertal development began in May, and spermatozoa production began in October prior to their second mating season. However, some larger juveniles attained puberty during the juvenile period. The captive juvenile, which was fed throughout the winter, attained puberty only 11 months after birth. These results suggest that if male raccoons can achieve enough body growth before the first mating season, puberty can be attained early. In both juveniles and yearlings, spermatozoa production was only observed after autumn. This timing coincided with the recrudescence of seasonally active spermatogenesis in adult males. Therefore, attaining puberty in male raccoons appears to require both adequate body nutrient development and several environmental factors that control seasonal testicular changes.

  9. Combination of Well-Logging Temperature and Thermal Remote Sensing for Characterization of Geothermal Resources in Hokkaido, Northern Japan

    Directory of Open Access Journals (Sweden)

    Bingwei Tian

    2015-03-01

    Full Text Available Geothermal resources have become an increasingly important source of renewable energy for electrical power generation worldwide. Combined Three Dimension (3D Subsurface Temperature (SST and Land Surface Temperature (LST measurements are essential for accurate assessment of geothermal resources. In this study, subsurface and surface temperature distributions were combined using a dataset comprised of well logs and Thermal Infrared Remote sensing (TIR images from Hokkaido island, northern Japan. Using 28,476 temperature data points from 433 boreholes sites and a method of Kriging with External Drift or trend (KED, SST distribution model from depths of 100 to 1500 m was produced. Regional LST was estimated from 13 scenes of Landsat 8 images. Resultant SST ranged from around 50 °C to 300 °C at a depth of 1500 m. Most of western and part of the eastern Hokkaido are characterized by high temperature gradients, while low temperatures were found in the central region. Higher temperatures in shallower crust imply the western region and part of the eastern region have high geothermal potential. Moreover, several LST zones considered to have high geothermal potential were identified upon clarification of the underground heat distribution according to 3D SST. LST in these zones showed the anomalies, 3 to 9 °C higher than the surrounding areas. These results demonstrate that our combination of TIR and 3D temperature modeling using well logging and geostatistics is an efficient and promising approach to geothermal resource exploration.

  10. Radar illusion via metamaterials

    Science.gov (United States)

    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.

  11. Java Radar Analysis Tool

    Science.gov (United States)

    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.

  12. Determination of radar MTF

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D. [Lawrence Livermore National Lab., CA (United States)

    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.

  13. Aspects of Radar Polarimetry

    OpenAIRE

    Lüneburg, Ernst

    2002-01-01

    This contribution is a tutorial introduction to the phenomenological theory of radar polarimetry for the coherent scatter case emphasizing monostatic backscattering and forward scattering (transmission). Characteristic similarities and differences between radar polarimetry and optical polarimetry and the role of linear and antilinear operators (time-reversal) are pointed out and typical polarimetric invariants are identified.

  14. The Cloud Radar System

    Science.gov (United States)

    Racette, Paul; Heymsfield, Gerald; Li, Lihua; Tian, Lin; Zenker, Ed

    2003-01-01

    Improvement in our understanding of the radiative impact of clouds on the climate system requires a comprehensive view of clouds including their physical dimensions, dynamical generation processes, and detailed microphysical properties. To this end, millimeter vave radar is a powerful tool by which clouds can be remotely sensed. The NASA Goddard Space Flight Center has developed the Cloud Radar System (CRS). CRS is a highly sensitive 94 GHz (W-band) pulsed-Doppler polarimetric radar that is designed to fly on board the NASA high-altitude ER-2 aircraft. The instrument is currently the only millimeter wave radar capable of cloud and precipitation measurements from above most all clouds. Because it operates from high-altitude, the CRS provides a unique measurement perspective for cirrus cloud studies. The CRS emulates a satellite view of clouds and precipitation systems thus providing valuable measurements for the implementation and algorithm validation for the upcoming NASA CloudSat mission that is designed to measure ice cloud distributions on the global scale using a spaceborne 94 GHz radar. This paper describes the CRS instrument and preliminary data from the recent Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE). The radar design is discussed. Characteristics of the radar are given. A block diagram illustrating functional components of the radar is shown. The performance of the CRS during the CRYSTAL-FACE campaign is discussed.

  15. Micropower impulse radar imaging

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Principles of modern radar radar applications

    CERN Document Server

    Scheer, James A

    2013-01-01

    Principles of Modern Radar: Radar Applications is the third of the three-volume seriesof what was originally designed to be accomplished in one volume. As the final volumeof the set, it finishes the original vision of a complete yet bounded reference for radartechnology. This volume describes fifteen different system applications or class ofapplications in more detail than can be found in Volumes I or II.As different as the applications described, there is a difference in how these topicsare treated by the authors. Whereas in Volumes I and II there is strict adherence tochapter format and leve

  17. [Survey of keratinophilic fungi from soils and mating behaviour of Microsporum canis from human ringworm cases in Hokkaido Prefecture in Japan].

    Science.gov (United States)

    Kubo, H

    1988-03-01

    From 383 (38.3%) of a total 1000 of soil samples, collected from Hokkaido prefecture, keratinophilic fungi have been isolated using hair baiting technique. The fungi isolated were as follows: 318 strains of Trichophyton ajelloi (including 90 strains of Arthroderma uncinatum), 59 of Microsporum cookei (including 13 of Nannizzia cajetani), 32 of Chrysosporium keratinophilum, 23 of C. tropicum, 15 of Chrysosporium anamorph of A. tuberculatum, 6 of T. terrestre (including 3 of A. insingulare and one of A. quadrifidum), 4 of Chrysosporium sp., 2 of M. canis (including one of N. otae), one of M. gypseum, and one of Ctenomyces serratus. This is the first isolation of N. otae from soil. Because of the successful isolation of N. otae (and its anamorph) from soil sample, (+) strain of M. canis was suggested to be popular in Hokkaido prefecture. The prevalence of (+) strain of M. canis was investigated using 279 isolates obtained from human ringworm cases. Among the 279 isolates, 257 were (-) mating type, 8 were (+) and 14 were nonreactive. Results of the present study indicate that the distribution of keratinophilic fungi from soils in Hokkaido prefecture is markedly different from that in the southern parts of Japan. The unexpected isolation of N. otae and its anamorph from soil samples as well as the significant population of N. otae(+) strain from human ringworms suggest the peculiar distribution pattern of N. otae (+) in Hokkaido prefecture.

  18. Estimating subsurface water volumes and transit times in Hokkaido river catchments, Japan, using high-accuracy tritium analysis

    Science.gov (United States)

    Gusyev, Maksym; Yamazaki, Yusuke; Morgenstern, Uwe; Stewart, Mike; Kashiwaya, Kazuhisa; Hirai, Yasuyuki; Kuribayashi, Daisuke; Sawano, Hisaya

    2015-04-01

    The goal of this study is to estimate subsurface water transit times and volumes in headwater catchments of Hokkaido, Japan, using the New Zealand high-accuracy tritium analysis technique. Transit time provides insights into the subsurface water storage and therefore provides a robust and quick approach to quantifying the subsurface groundwater volume. Our method is based on tritium measurements in river water. Tritium is a component of meteoric water, decays with a half-life of 12.32 years, and is inert in the subsurface after the water enters the groundwater system. Therefore, tritium is ideally suited for characterization of the catchment's responses and can provide information on mean water transit times up to 200 years. Only in recent years has it become possible to use tritium for dating of stream and river water, due to the fading impact of the bomb-tritium from thermo-nuclear weapons testing, and due to improved measurement accuracy for the extremely low natural tritium concentrations. Transit time of the water discharge is one of the most crucial parameters for understanding the response of catchments and estimating subsurface water volume. While many tritium transit time studies have been conducted in New Zealand, only a limited number of tritium studies have been conducted in Japan. In addition, the meteorological, orographic and geological conditions of Hokkaido Island are similar to those in parts of New Zealand, allowing for comparison between these regions. In 2014, three field trips were conducted in Hokkaido in June, July and October to sample river water at river gauging stations operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). These stations have altitudes between 36 m and 860 m MSL and drainage areas between 45 and 377 km2. Each sampled point is located upstream of MLIT dams, with hourly measurements of precipitation and river water levels enabling us to distinguish between the snow melt and baseflow contributions

  19. Radar cross section

    CERN Document Server

    Knott, Gene; Tuley, Michael

    2004-01-01

    This is the second edition of the first and foremost book on this subject for self-study, training, and course work. Radar cross section (RCS) is a comparison of two radar signal strengths. One is the strength of the radar beam sweeping over a target, the other is the strength of the reflected echo sensed by the receiver. This book shows how the RCS ?gauge? can be predicted for theoretical objects and how it can be measured for real targets. Predicting RCS is not easy, even for simple objects like spheres or cylinders, but this book explains the two ?exact? forms of theory so well that even a

  20. Radar and electronic navigation

    CERN Document Server

    Sonnenberg, G J

    2013-01-01

    Radar and Electronic Navigation, Sixth Edition discusses radar in marine navigation, underwater navigational aids, direction finding, the Decca navigator system, and the Omega system. The book also describes the Loran system for position fixing, the navy navigation satellite system, and the global positioning system (GPS). It reviews the principles, operation, presentations, specifications, and uses of radar. It also describes GPS, a real time position-fixing system in three dimensions (longitude, latitude, altitude), plus velocity information with Universal Time Coordinated (UTC). It is accur

  1. Evaluation of Nitrogen Cycling Associated with Agricultural Production and Environmental Load in a Mountain Region, in Hokkaido, Japan

    Institute of Scientific and Technical Information of China (English)

    LIANG Lei; JIN Datian; HU Ning

    2008-01-01

    This study examined the nitrogen cycling associated with agricultural production and environmental load in central Hokkaido. The nitrogen (N) budget analysis model offers a new set of tools for evaluating N cycling in agro-ecosystems. The cycling index (CI) is a useful tool for estimating optimal N flows in farmlands. The fertilization index (FI) is a useful indicator for characterizing the N flows related to farms. Using these parameters, we analyzed all farm systems to estimate the optimal N cycling for minimizing N pollution in groundwater and maximizing agricultural production in mountain regions of Japan. The results showed that the critical N application rate (chemical fertilizer + manure) was 143.3 kg N ha-1 y-1. The critical inter-system input (chemical fertilizer N, imported food and feed N, and natural supplied N) was 169.9 kg N ha-1y-1.

  2. Wind Profiling Radar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Clutter present in radar return signals as used for wind profiling is substantially removed by carrying out a Daubechies wavelet transformation on a time series of...

  3. Imaging Radar Polarimetry

    Science.gov (United States)

    vanZyl, J. J.; Zebker, H. A.

    1993-01-01

    In this paper, we review the state of the art in imaging radar polarimetry, examine current developments in sensor technology and implementation for recording polarimetric measurements, and describe techniques and areas of application for the new remote sensing data.

  4. Serologic evidence of Brucella infection in pinnipeds along the coast of Hokkaido, the northernmost main island of Japan.

    Science.gov (United States)

    Abe, Erika; Ohishi, Kazue; Ishinazaka, Tsuyoshi; Fujii, Kei; Maruyama, Tadashi

    2017-04-01

    Brucella infection in Hokkaido was serologically surveyed in four species of pinnipeds inhabiting Cape Erimo during 2008-2013 and the Shiretoko Peninsula in 1999 by ELISA using Brucella abortus and B. canis as antigens. Anti-Brucella positive sera showed higher absorbance to B. abortus than B. canis in almost all samples. Anti-B. abortus antibodies were detected in serum samples from 24% (n = 55) of Western Pacific harbor seals (Phoca vitulina stejnegeri) in Cape Erimo and from 66% (n = 41) of spotted seals (P. largha), 15% (n = 20) of ribbon seals (Histriophoca fasciata) and 18% (n = 17) of Western Steller's sea lions (Eumetopias jubatus jubatus) in the Shiretoko Peninsula. Anti-Brucella antibodies were detected at higher absorbance in 1- to 4-year-old harbor seals than in the pups and mature animals, suggesting either that Brucella infection mainly occurs after weaning or that it is maternally transmitted to pups with premature or suppressed immunity. Anti-Brucella antibodies were detected in both immature and mature spotted seals and ribbon seals, with higher absorbance in the former. The antibodies were detected only in mature Western Steller's sea lions. Western blot analysis of the serum samples showed some differences in band appearances, namely discrete versus smeary, and in the number of bands, indicating that multiple different Brucella may be prevalent in pinnipeds in Hokkaido. Alternatively, the Brucella of pinnipeds may have some intra-species diversity. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

  5. Radar Landmass Simulation Computer Programming (Interim Report).

    Science.gov (United States)

    RADAR SCANNING, TERRAIN), (*NAVAL TRAINING, RADAR OPERATORS), (*FLIGHT SIMULATORS, TERRAIN AVOIDANCE), (* COMPUTER PROGRAMMING , INSTRUCTION MANUALS), PLAN POSITION INDICATORS, REAL TIME, DISPLAY SYSTEMS, RADAR IMAGES, SIMULATION

  6. Downhole pulse radar

    Science.gov (United States)

    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.

  7. A barrier radar concept

    Science.gov (United States)

    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.

  8. Airport Surveillance Radar : Model 8 -

    Data.gov (United States)

    Department of Transportation — The Airport Surveillance Radar Model 8 (ASR-8) is a short-range (60 nautical mile (nmi)), analog radar system used to detect and report the presence and location of...

  9. Airport Surveillance Radar : Model 7 -

    Data.gov (United States)

    Department of Transportation — The Airport Surveillance Radar Model 7 (ASR-7) is a short-range (60 nautical miles (nmi)) analog radar system used to detect and report the presence and location of...

  10. Radar for tracer particles

    CERN Document Server

    Ott, Felix; Huang, Kai

    2016-01-01

    We introduce a radar system capable of tracking a $5$mm spherical target continuously in three dimensions. The $10$GHz (X-band) radar system has a transmission power of $1$W and operates in the near field of the horn antennae. By comparing the phase shift of the electromagnetic wave traveling through the free space with an IQ-Mixer, we obtain the relative movement of the target with respect to the antennae. From the azimuth and inclination angles of the receiving antennae obtained in the calibration, we reconstruct the target trajectory in a three-dimensional Cartesian system. Finally, we test the tracking algorithm with target moving in circular as well as in pendulum motions, and discuss the capability of the radar system.

  11. Localizing Ground-Penetrating Radar

    Science.gov (United States)

    2014-11-01

    ing Ground-Penetrating Radar (LGPR) uses very high frequency (VHF) radar reflections of underground features to generate base- line maps and then...Innovative ground- penetrating radar that maps underground geological features provides autonomous vehicles with real-time localization. Localizing...NOV 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Localizing Ground-Penetrating Radar 5a. CONTRACT NUMBER

  12. Mode S Baseline Radar Tracking.

    Science.gov (United States)

    1982-11-01

    range units and 20 azimuth units) overlaying the position of the beacon reports. In the cases analyzed where beacon reports were not radar reinforced ...82/53 j~ C ~ 7 C _ _ _ _ _ _ 4. Title end Su.btitle 5. Neget at. November 1982 MDDE S BASELINE RADAR TRACKIN4G 6. Poelin Orgeuianti.. Cede ACT-100...Ground Clutter 33 Mode S/ARTS III 100-Scan False Radar Track Summary 74 34 Percent Beacon Radar Reinforcement 77 vii INTRODUCTION PURPOSE. The purpose of

  13. The impacts of disturbance on the spatial and temporal variations of carbon balance in forest ecosystems on Hokkaido, Japan

    Science.gov (United States)

    Hirata, R.; Ito, A.; Saigusa, N.

    2013-12-01

    Carbon balance in a forest ecosystem can be quite variable if the forest ecosystem structure and function change abruptly as a result of disturbance and subsequent recovery processes. A map of forest age is useful for upscaling carbon balance from the site level to a regional scale because it provides information about when disturbance occurred and how it spread over a wide area. In this study, we used maps of forest age to help evaluate spatial and temporal variations in the carbon balance of forest ecosystems with a process-based ecosystem model. Forests less than 60 years old account for more than 70% of Japanese forests because forest stands have been quickly replaced after disturbance caused by thinning, harvesting, plantations, fires, typhoons, and insect damage. However, few studies have attempted to quantify how much disturbance affects the spatial and temporal variations of carbon balance. In this study, we focused on how disturbance and subsequent re-growth affected the spatial and temporal variations of the carbon balance of forests. We adapted the Vegetation Integrative SImulator for Trace Gases (VISIT) model in order to simulate carbon balance on Hokkaido, which is the northernmost island of Japan. The model was validated with tower flux data obtained from forests with ages between 0 and 43 years. Simulations of the carbon balance were conducted for the period 1948-2010 after a 1000-year spin-up at a spatial resolution of 1 km × 1 km. We investigated two case studies of simulated carbon balance: one that took into account the spatial distribution of forest ages derived from forest inventory data, and another that ignored the impact of disturbance (i.e., no disturbance and a homogeneous distribution of ages). We first focused on the difference from 2000-2010 in the spatial distribution of net ecosystem production (NEP) between the disturbance and non-disturbance cases. In the non-disturbance case, the temporal and spatial changes in NEP were gradual

  14. Systems and Methods for Radar Data Communication

    Science.gov (United States)

    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.

  15. Noise Radar Technology Basics

    Science.gov (United States)

    2006-12-01

    poursuite, estimation Doppler, polarimétrie, interférométrie, sondage du sol ou profilage de la sous- surface , détection, imagerie SAR (radar à synthèse...mesure de distance et d’estimation Doppler. Deux récepteurs de traitement cohérent, soit le récepteur de corrélation et le récep- teur de traitement DSP... traitement spectral double) des échos radar sont décrits et une estimation de leur portée est présentée. Les capacités LPI (faible probabilité

  16. Ground penetrating radar

    CERN Document Server

    Daniels, David J

    2004-01-01

    Ground-penetrating radar has come to public attention in recent criminal investigations, but has actually been a developing and maturing remote sensing field for some time. In the light of recent expansion of the technique to a wide range of applications, the need for an up-to-date reference has become pressing. This fully revised and expanded edition of the best-selling Surface-Penetrating Radar (IEE, 1996) presents, for the non-specialist user or engineer, all the key elements of this technique, which span several disciplines including electromagnetics, geophysics and signal processing. The

  17. Human walking estimation with radar

    NARCIS (Netherlands)

    Dorp, Ph. van; Groen, F.C.A.

    2003-01-01

    Radar can be used to observe humans that are obscured by objects such as walls. These humans cannot be visually observed. The radar measurements are used to animate an obscured human in virtual reality. This requires detailed information about the motion. The radar measurements give detailed informa

  18. Radar Test Range Design Considerations.

    Science.gov (United States)

    1980-04-29

    radar cross section associated with dihedral and trihedral corner reflectors is highly dependent upon the squareness or alignment of the...slightly misaligned. We now show how the radar cross section for dihedral and trihedral corner reflectors depends upon their surface misalignment. All...coefficients, p and q, for the dihedral corner reflector , one must consider the radar cross section

  19. Status Of Imaging Radar Polarimetry

    Science.gov (United States)

    Van Zyl, Jakob J.; Zebker, Howard A.

    1991-01-01

    Report pulls together information on imaging radar polarimetry from a variety of sources. Topics include theory, equipment, and experimental data. Reviews state of the art, examines current applicable developments in radar equipment, describes recording and processing of radar polarimetric measurements, and discusses interpretation and application of resulting polarimetric images.

  20. Human walking estimation with radar

    NARCIS (Netherlands)

    Dorp, Ph. van; Groen, F.C.A.

    2003-01-01

    Radar can be used to observe humans that are obscured by objects such as walls. These humans cannot be visually observed. The radar measurements are used to animate an obscured human in virtual reality. This requires detailed information about the motion. The radar measurements give detailed

  1. Coded continuous wave meteor radar

    OpenAIRE

    2015-01-01

    The concept of coded continuous wave meteor radar is introduced. The radar uses a continuously transmitted pseudo-random waveform, which has several advantages: coding avoids range aliased echoes, which are often seen with commonly used pulsed specular meteor radars (SMRs); continuous transmissions maximize pulse compression gain, allowing operation with significantly lower peak transmit power; the temporal resolution can be changed after ...

  2. Different responses of northern and southern high latitude ionospheric convection to IMF rotations: a case study based on SuperDARN observations

    Directory of Open Access Journals (Sweden)

    D. Ambrosino

    2009-06-01

    Full Text Available We use SuperDARN data to study high-latitude ionospheric convection over a three hour period (starting at 22:00 UT on 2 January 2003, during which the Interplanetary Magnetic Field (IMF flipped between two states, one with By>>|Bz| and one with Bz>0, both with negative Bx. We find, as expected from previous works, that day side ionospheric convection is controlled by the IMF in both hemispheres. For strongly northward IMF, we observed signatures of two reverse cells, both in the Northern Hemisphere (NH and in the Southern Hemisphere (SH, due to lobe reconnection. On one occasion, we also observed in the NH two viscous cells at the sides of the reverse cell pair. For duskward IMF, we observed in the NH a large dusk clockwise cell, accompanied by a smaller dawn cell, and the signature of a corresponding pattern in the SH. On two occasions, a three cell pattern, composed of a large clockwise cell and two viscous cells, was observed in the NH. As regards the timings of the NH and SH convection reconfigurations, we find that the convection reconfiguration from a positive Bz dominated to a positive By dominated pattern occurred almost simultaneously (i.e. within a few minutes in the two hemispheres. On the contrary, the reconfiguration from a By dominated to a northward IMF pattern started in the NH 8–13 min earlier than in the SH. We suggest that part of such a delay can be due to the following mechanism: as IMF Bx<0, the northward-tailward magnetosheath magnetic field reconnects with the magnetospheric field first tailward of the northern cusp and later on tailward of the southern cusp, due to the IMF draping around the magnetopause.

  3. Dinoflagellate cyst biostratigraphy and age of the Oligocene Momijiyama formation, Yubari Coal-Field, central Hokkaido, Japan; Hokkaido yubari tanden chiiki, zenshinto momijiyamaso no kaben moso kasekisojo to nendai

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, H.; Miwa, M. [Japan Petroleum Exploration Co. Ltd., Chiba (Japan). JAPEX Research Center

    1998-01-15

    The Momijiyama formation distributed in the Yubari coalfield region of Hokkaido is one of the typical sea Oligocenes in the northern Japan. However, there has been much argument about the age of the Momijiyama formation. This paper reports newly-obtained findings concerning the upper limit age of the Momijiyama formation determined by the analysis of a dinoflagellate fossil, an organic microfossil, conducting a fission track (FT) age determination, and putting together the results of the analysis and determination and the results of the analysis of dinoflagellate fossil reported by Kurita and Matsuoka (1994). It can currently be concluded on the basis of both the data on the dinoflagellate cyst biostratigraphy which were obtained in the Hobetsu region and those on the radioactive data that the upper limit age of the Momijiyama formation is an initial period of the Oligocene epoch. The age of the floating foraminifer and the calcareous nannofossil produced from the upper portion of the Horonai formation, a formation on the lower layer of the Momijiyama formation is the final period of the Eocene or the initial period of the Oligocene. Therefore, it is considered that the lower limit age of the Momijiyama formation is substantially before or after the transition from the Eocene epoch to the Oligocene epoch. 19 refs., 4 figs., 1 tab.

  4. The Newcastle meteor radar

    Science.gov (United States)

    Keay, Colin

    1987-01-01

    A brief history and development of the Newcastle Meteor Radar system is given. Also described are its geographical coordinates and its method of operation. The initial objective when the project was commenced was to develop an entirely digital analyzer capable of recognizing meteor echo signals and recording as many of their parameters as possible. This objective was achieved.

  5. Compressive CFAR radar detection

    NARCIS (Netherlands)

    Anitori, L.; Otten, M.P.G.; Rossum, W.L. van; Maleki, A.; Baraniuk, R.

    2012-01-01

    In this paper we develop the first Compressive Sensing (CS) adaptive radar detector. We propose three novel architectures and demonstrate how a classical Constant False Alarm Rate (CFAR) detector can be combined with ℓ1-norm minimization. Using asymptotic arguments and the Complex Approximate Messag

  6. Compressive CFAR Radar Processing

    NARCIS (Netherlands)

    Anitori, L.; Rossum, W.L. van; Otten, M.P.G.; Maleki, A.; Baraniuk, R.

    2013-01-01

    In this paper we investigate the performance of a combined Compressive Sensing (CS) Constant False Alarm Rate (CFAR) radar processor under different interference scenarios using both the Cell Averaging (CA) and Order Statistic (OS) CFAR detectors. Using the properties of the Complex Approximate Mess

  7. Synthetic Aperture Radar Interferometry

    Science.gov (United States)

    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. Spaceborne Radar Study

    Science.gov (United States)

    1974-06-28

    via either the oomm beam or the omnichannel . Satellite instrumentation data are sent to the ground station following every radar signal transmission...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

  9. Integrated Monitoring of the Soya Warm Current Using HF Ocean Radars, Satellite Altimeters, Coastal Tide Gauges, and a Bottom-Mounted ADCP

    Science.gov (United States)

    Ebuchi, N.; Fukamachi, Y.; Ohshima, K. I.; Wakatsuchi, M.

    2007-12-01

    The Soya Warm Current (SWC) is a coastal boundary current, which flows along the coast of Hokkaido in the Sea of Okhotsk. The SWC flows into the Sea of Okhotsk from the Sea of Japan through the Soya/La Perouse Strait, which is located between Hokkaido, Japan, and Sakhalin, Russia. It supplies warm, saline water in the Sea of Japan to the Sea of Okhotsk and largely affects the ocean circulation and water mass formation in the Sea of Okhotsk, and local climate, environment and fishery in the region. However, the SWC has never been continuously monitored due to the difficulties involved in field observations related to, for example, severe weather conditions in the winter, political issues at the border strait, and conflicts with fishing activities in the strait. Detailed features of the SWC and its variations have not yet been clarified. In order to monitor variations in the SWC, three HF ocean radar stations were installed around the strait. The radar covers a range of approximately 70 km from the coast. It is shown that the HF radars clearly capture seasonal and subinertial variations of the SWC. The velocity of the SWC reaches its maximum, approximately 1 m/s, in summer, and weakens in winter. The velocity core is located 20 to 30 km from the coast, and its width is approximately 50 km. The surface transport by the Soya Warm Current shows a significant correlation with the sea level difference along the strait, as derived from coastal tide gauge records. The cross-current sea level difference, which is estimated from the sea level anomalies observed by the Jason-1 altimeter and a coastal tide gauge, also exhibits variation in concert with the surface transport and along-current sea level difference.

  10. Radar Observations of Asteroids

    Science.gov (United States)

    Ostro, S. J.

    2003-05-01

    During the past 25 years, radar investigations have provided otherwise unavailable information about the physical and dynamical properties of more than 200 asteroids. Measurements of the distribution of echo power in time delay and Doppler frequency provide two-dimensional images with spatial resolution as fine as a decameter. Sequences of delay-Doppler images can be used to produce geologically detailed three-dimensional models, to define the rotation state precisely, to constrain the internal density distribution, and to estimate the trajectory of the object's center of mass. Radar wavelengths (4 to 13 cm) and the observer's control of transmitted and received polarizations make the observations sensitive to near-surface bulk density and macroscopic structure. Since delay-Doppler positional measurements are orthogonal to optical angle measurements and typically have much finer fractional precision, they are powerful for refining orbits and prediction ephemerides. Radar astrometry can add decades or centuries to the interval over which an asteroid's close Earth approaches can accurately be predicted and can significantly refine collision probability estimates based on optical astrometry alone. In the highly unlikely case that a small body is on course for an Earth collision in this century, radar reconnaissance would almost immediately distinguish between an impact trajectory and a near miss and would dramatically reduce the difficulty and cost of any effort to prevent the collision. The sizes and rotation periods of radar-detected asteroids span more than four orders of magnitude. These observations have revealed both stony and metallic objects, elongated and nonconvex shapes as well as nearly featureless spheroids, small-scale morphology ranging from smoother than the lunar regolith to rougher than the rockiest terrain on Mars, craters and diverse linear structures, non-principal-axis spin states, contact binaries, and binary systems.

  11. Methicillin-resistant Staphylococcus aureus carriage among veterinary staff and dogs in private veterinary clinics in Hokkaido, Japan.

    Science.gov (United States)

    Ishihara, Kanako; Saito, Mieko; Shimokubo, Natsumi; Muramatsu, Yasukazu; Maetani, Shigeki; Tamura, Yutaka

    2014-03-01

    To explore the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in veterinary medical practices, MRSA carriage was tested among 96 veterinarians (Vets), 70 veterinary technicians (VTs) and 292 dogs with which they had contact at 71 private veterinary clinics (VCs) in Hokkaido, Japan. MRSA isolates were obtained from 22 Vets [22.9%] and 7 VTs [10%]. The prevalence of MRSA among Vets was as high as that found in an academic veterinary hospital in our previous study. In contrast, only two blood donor dogs and one dog with liver disease (1.0%, 3/292) yielded MRSA. All MRSA-positive dogs were reared or treated in different VCs, in each of which at least one veterinary staff member carrying MRSA worked. Sequence types (ST) identified by multilocus sequence typing, spa types, and SCCmec types for canine MRSA isolates (ST5-spa t002-SCCmec II [from two dogs] or ST30-spa t021-SCCmec IV [from a dog]) were concordant with those from veterinary staff members in the same clinics as the MRSA-positive dogs, with which they had potentially had contact. Most MRSA isolates from veterinary staff were the same genotype (SCCmec type II and spa type t002) as a major hospital-acquired MRSA clone in Japan. The remaining MRSA was the same genotypes as domestic and foreign community-associated MRSA. Measures against MRSA infection should be provided in private VCs.

  12. Cold-induced vasodilatation of finger and maximal oxygen consumption of young female athletes born in Hokkaido

    Science.gov (United States)

    Moriya, Kiyoshi; Nakagawa, Koya

    1990-03-01

    To determine whether there is a direct correlation between endurance capacity and cold tolerance, maximal oxygen consumption (VO2max), and cold-induced vasodilatation (CIVD), we measured these factors in 14 young female athletes born in Hokkaido, Japan's northernmost island. We determined the VO2max by a standard incremental test on a cycle ergometer and measured the oxygen consumption (VO2) by means of the Douglas-bag method. We determined the CIVD reaction by measuring the skin temperature of the left middle finger during immersion in cold water at 0°C for 20 min. The athletes showed significant positive correlations between VO2max, expressed as l/min, and CIVD as well as other peripheral cold tolerance indexes (resistance index against frostbite and CIVD index). The body weight VO2max (VO2max/kg body weight) failed to correlate significantly with either the CIVD or with other cold tolerance indexes. These results suggest that CIVD in females may depend on factors other than those determined in this study, in addition to the functional spread of the vascular beds in peripheral tissues, including striated muscle; it is known that the size and the vascular bed in this tissue are affected by exercise training and that this results in the elevation of VO2max and VO2max/kg body weight.

  13. Effects of silviculture treatments in a hurricane-damaged forest on car- bon storage and emissions in central Hokkaido, Japan

    Institute of Scientific and Technical Information of China (English)

    Toshiaki Owari; Naoto Kamata; Takeshi Tange; Mikio Kaji; Akio Shimomura

    2011-01-01

    Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm (understory vegetation removal) led to the largest amount of carbon stored (64.7 t·ha 1 C). Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid (L. gmelinii var. japonica × L. kaempferi) plantation (80.3 t·ha-1 C). The plantation of Abies sachalinensis was not successful at accumulating carbon (40.5·ha-1 C). The amount of carbon emitted from silviculture operations was 0.050.14 t·ha 1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should be performed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests.

  14. Continuous measurement of CO2 flux through the snowpack in a dwarf bamboo ecosystem on Rishiri Island, Hokkaido, Japan

    Science.gov (United States)

    Zhu, Chunmao; Nakayama, Momoko; Yoshikawa Inoue, Hisayuki

    2014-09-01

    To investigate the dynamics and environmental drivers of CO2 flux through the winter snowpack in a dwarf bamboo ecosystem (Hokkaido, northeast Japan), we constructed an automated sampling system to measured CO2 concentrations at five different levels in the snowpack, from the base to the upper snow surface. Using a gas diffusion approach, we estimated an average apparent soil CO2 flux of 0.26 μmol m-2 s-1 during the snow season (December-April); temporally, the CO2 flux increased until mid-snow season, but showed no clear trend thereafter; late-season snow-melting events resulted in rapid decreases in apparent CO2 flux values. Air temperature and subnivean CO2 flux exhibited a positive linear relationship. After eliminating the effects of wind pumping, we estimated the actual soil CO2 flux (0.41 μmol m-2 s-1) to be 54% larger than the apparent flux. This study provides new constraints on snow-season carbon emissions in a dwarf bamboo ecosystem in northeast Asia.

  15. Disturbances in VHF/UHF telemetry links as a possible effect of the 2003 Hokkaido Tokachi-oki earthquake

    Directory of Open Access Journals (Sweden)

    H. Nagamoto

    2008-08-01

    Full Text Available The data on radio telemetry links (for water information at VHF/UHF in Hokkaido are used to investigate the rate of disturbances on radio links (or connection failure and its association with a huge earthquake, Tokachi-oki earthquake on 26 September 2003. Especially, the telemetry links at the Tokachi region closest to the earthquake epicenter, showed a significant increase in disturbances on radio links two weeks to a few days before the earthquake on the basis of analysis during a long interval from 1 June 2002 to 3 November 2007 (over 5 years. We suggest that these severe disturbances in VHF/UHF telemetry links are attributed to the generation of seismogenic VHF/UHF radio noises (emissions. Based on this idea, we have estimated that the intensity of these seismogenic emissions is on the order of 10–19 dB μV/m. Finally, the present result was compared with other physical parameters already obtained for this earthquake.

  16. Influence of dried Hokkaido pumpkin and ascorbic acid addition on chemical properties and colour of corn extrudates.

    Science.gov (United States)

    Obradović, Valentina; Babić, Jurislav; Šubarić, Drago; Jozinović, Antun; Ačkar, Đurđica; Klarić, Ilija

    2015-09-15

    The influence of Hokkaido pumpkin powder (PP) addition to corn grits at levels 4%, 6%, and 8% and ascorbic acid (AA) addition at levels 0.5% and 1% was evaluated. Extrusion was done using a single-screw extruder at two temperature regimes: 135/170/170°C (E1) and 100/150/150°C (E2). Mathematical models that describe the influence of additives on the colour of extrudates were determined. Raw extrusion mixtures as well as obtained extrudates were tested for ascorbic acid, polyphenol, proteins, fat, crude fibre, ash and carotenoids content, and antioxidant activity. E1 extrusion regime acted favourably on polyphenols, crude fibre content, and antioxidant activity. It also caused higher fat degradation than E2 extrusion. Xanthophylls (lutein and zeaxanthin) were less sensitive to extrusion than carotenes (α-carotene, 9-cis-β-carotene and 13-cis-β-carotene). Ascorbic acid was more sensitive to higher extrusion temperatures (49-76% degradation). It provided protection to carotenoids and consequently the colour of the extrudates.

  17. Difference in Size at Maturity in Annual and Overwintering Generations in the Tanaidacean Zeuxo sp. in Oshoro Bay, Hokkaido, Japan.

    Science.gov (United States)

    Kakui, Keiichi; Hayakawa, Yoshinobu; Katakura, Haruo

    2017-04-01

    We investigated the life cycle of the tanaidid Zeuxo sp. 1 (Crustacea: Peracarida: Tanaidacea), which lives epiphytically in dwelling tubes on the algae Sargassum spp. and Neorhodomela aculeata in Oshoro Bay, Hokkaido, Japan. We obtained data on its population size distribution, age structure, and reproductive phenology through monthly sampling from April 2011 to June 2012. From these data, we detected an overwintering group (F0) that arises from mancae that are released in autumn, overwinters, reproduces the following spring, and then disappears. The overwintering group produces mancae (F1) that reach maturity and themselves reproduce within six weeks after release; the F1, mancae give rise to an F2 and possibly an F3 generation within a single summer. We refer to individuals that reproduce in the same summer that they were released as the 'annual group'. Reproduction overall was restricted to the period from May to October, when the seasurface temperature exceeded 10°C. During both years, overwintering females first became reproductive in May. Reproduction in the annual group began in June and continued through mid-October. Mancae were observed in samples from June through October. The two groups differed significantly in size at reproduction; compared to the annual group, females in the overwintering group reproduced at larger minimum and average body sizes, and males began to express enlarged chelae, a secondary sexual character, at a larger size. The difference in size at maturity may be related to the differences in water temperature during the main period of growth and maturation.

  18. Ice-brine and planktonic microheterotrophs from Saroma-ko Lagoon, Hokkaido (Japan): quantitative importance and trophodynamics

    Science.gov (United States)

    Sime-Ngando, Télesphore; Juniper, S. Kim; Demers, Serge

    1997-02-01

    Biologists have rarely had the opportunity to investigate the community characteristics and dynamics of heterotrophic microorganisms in highly productive first-year sea ice. In this study, sterile seawater was used as a salinity buffer to extract the ice-brine microheterotroph communities (bacteria, flagellates and ciliates) from a coastal lagoon in Japan (Saroma-ko, Hokkaido; 44°N, 144°E) during the late winter (February—March) of 1992. This procedure reduced osmotic shock during the melting of ice cores and allowed the recovery of up to 323% more cells than the traditional melting method. Most of the organisms were concentrated in the bottom 3-4 cm of the ice, where abundances were up to 33 times higher than in the plankton. In ice and plankton samples, heterotrophic flagellates were dominated by small species (sampling period while protozoa increased or attained their maximum number in late winter, toward the end of the sampling period. These observations support previous suggestions of the existence of a functional microbial food web within the sea-ice community. Heterotrophic flagellate biomass greatly exceeded bacterial biomass in the sea ice (30-60 x). Coupled with similar potential growth rates, this suggests the utilization of additional (non-bacterial) food items by ice-brine flagellates. Finally, the effects of salinity variations (ranging between 15 and 120 psu) on potential microheterotroph growth rates are discussed.

  19. An MSK Radar Waveform

    Science.gov (United States)

    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

  20. Radar cross-sectional study using noise radar

    Science.gov (United States)

    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.

  1. Netted LPI RADARs

    Science.gov (United States)

    2011-09-01

    easier and, since they cover most of the space around the antenna, can expose it easily at various bearings ). Typical sidelobe levels for conventional...modern radar systems results in an electro- magnetic environment where the receiver should expect very few pulses. Staggered PRF and frequency agility...detector, a logarithmic amplitude compressor , and a signal encoder. All subunits are digitally controlled by computer as to frequency, sweep rate, and

  2. Imaging synthetic aperture radar

    Science.gov (United States)

    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.

  3. The Radar Roadmap

    Science.gov (United States)

    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

  4. Radar Investigations of Asteroids

    Science.gov (United States)

    Ostro, S.

    2004-05-01

    Radar investigations have provided otherwise unavailable information about the physical and dynamical properties of about 230 asteroids. Measurements of the distribution of echo power in time delay (range) and Doppler frequency (line-of-sight velocity) provide two-dimensional images with spatial resolution as fine as a decameter. Sequences of delay-Doppler images can be used to produce geologically detailed three-dimensional models, to define the rotation state precisely, to constrain the internal density distribution, and to estimate the trajectory of the object's center of mass. Radar wavelengths (4 to 13 cm) and the observer's control of transmitted and received polarizations make the observations sensitive to near-surface bulk density and macroscopic structure. Since delay-Doppler measurements are orthogonal to optical angle measurements and typically have much finer fractional precision, they are powerful for refining orbits and prediction ephemerides. Such astrometric measurements can add decades or centuries to the interval over which an asteroid's close Earth approaches can accurately be predicted and can significantly refine collision probability estimates based on optical astrometry alone. In the highly unlikely case that a small body is on course for an Earth collision in this century, radar reconnaissance would almost immediately distinguish between an impact trajectory and a near miss and would dramatically reduce the difficulty and cost of any effort to prevent the collision. The sizes and rotation periods of radar-detected asteroids span more than four orders of magnitude. The observations have revealed both stony and metallic objects, elongated and nonconvex shapes as well as nearly featureless spheroids, small-scale morphology ranging from smoother than the lunar regolith to rougher than the rockiest terrain on Mars, craters and diverse linear structures, non-principal-axis spin states, contact binaries, and binary systems.

  5. Radar clutter classification

    Science.gov (United States)

    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.

  6. Nordic Snow Radar Experiment

    Science.gov (United States)

    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.

  7. Detection of Weather Radar Clutter

    DEFF Research Database (Denmark)

    Bøvith, Thomas

    2008-01-01

    Weather radars provide valuable information on precipitation in the atmosphere but due to the way radars work, not only precipitation is observed by the weather radar. Weather radar clutter, echoes from non-precipitating targets, occur frequently in the data, resulting in lowered data quality....... Especially in the application of weather radar data in quantitative precipitation estimation and forecasting a high data quality is important. Clutter detection is one of the key components in achieving this goal. This thesis presents three methods for detection of clutter. The methods use supervised...... and precipitating and non-precipitating clouds. Another method uses the difference in the motion field of clutter and precipitation measured between two radar images. Furthermore, the direction of the wind field extracted from a weather model is used. The third method uses information about the refractive index...

  8. FMWC Radar for Breath Detection

    DEFF Research Database (Denmark)

    Suhr, Lau Frejstrup; Tafur Monroy, Idelfonso; Vegas Olmos, Juan José

    We report on the experimental demonstration of an FMCW radar operating in the 25.7 - 26.6 GHz range with a repetition rate of 500 sweeps per second. The radar is able to track the breathing rate of an adult human from a distance of 1 meter. The experiments have utilized a 50 second recording window...... to accurately track the breathing rate. The radar utilizes a saw tooth modulation format and a low latency receiver. A breath tracking radar is useful both in medical scenarios, diagnosing disorders such as sleep apnea, and for home use where the user can monitor its health. Breathing is a central part of every...... radar chip which, through the use of a simple modulation scheme, is able to measure the breathing rate of an adult human from a distance. A high frequency output makes sure that the radar cannot penetrate solid obstacles which is a wanted feature in private homes where people therefore cannot measure...

  9. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  10. Application of tritium in precipitation and baseflow in Japan: a case study of groundwater transit times and storage in Hokkaido watersheds

    Science.gov (United States)

    Gusyev, Maksym A.; Morgenstern, Uwe; Stewart, Michael K.; Yamazaki, Yusuke; Kashiwaya, Kazuhisa; Nishihara, Terumasa; Kuribayashi, Daisuke; Sawano, Hisaya; Iwami, Yoichi

    2016-07-01

    In this study, we demonstrate the application of tritium in precipitation and baseflow to estimate groundwater transit times and storage volumes in Hokkaido, Japan. To establish the long-term history of tritium concentration in Japanese precipitation, we used tritium data from the global network of isotopes in precipitation and from local studies in Japan. The record developed for Tokyo area precipitation was scaled for Hokkaido using tritium values for precipitation based on wine grown at Hokkaido. Then, tritium concentrations measured with high accuracy in river water from Hokkaido, Japan, were compared to this scaled precipitation record and used to estimate groundwater mean transit times (MTTs). A total of 16 river water samples in Hokkaido were collected in June, July, and October 2014 at 12 locations with altitudes between 22 and 831 m above sea level and catchment areas between 14 and 377 km2. Measured tritium concentrations were between 4.07 (± 0.07) TU and 5.29 (± 0.09) TU in June, 5.06 (± 0.09) TU in July, and between 3.75 (± 0.07) TU and 4.85 (± 0.07) TU in October. We utilised TracerLPM (Jurgens et al., 2012) for MTT estimation and introduced a Visual Basic module to automatically simulate tritium concentrations and relative errors for selected ranges of MTTs, exponential-piston ratios, and scaling factors of tritium input. Using the exponential (70 %) piston flow (30 %) model (E70 %PM), we simulated unique MTTs for seven river samples collected in six Hokkaido headwater catchments because their low tritium concentrations were no longer ambiguous. These river catchments are clustered in similar hydrogeological settings of Quaternary lava as well as Tertiary propylite formations near Sapporo city. However, nine river samples from six other catchments produced up to three possible MTT values with E70 % PM due to the interference by the tritium from the atmospheric hydrogen bomb testing 5-6 decades ago. For these catchments, we show that tritium in

  11. Spatial distribution of microbial populations and carbon cycle in the subsurface environment of the Horonobe area, Hokkaido, Japan

    Science.gov (United States)

    Amano, Y.; Ise, K.; Terashima, M.; Sasaki, Y.; Amamiya, H.; Yoshikawa, H.

    2014-12-01

    Microorganisms are widely distributed in the subsurface environments. However, the distribution, role and rate of metabolisms, and the source of their activity are not well known. In this study, we investigated deep groundwater samples from sedimentary rocks, containing saturated methane and CO2, using boreholes at the Horonobe Underground Research Laboratory (URL), northern Hokkaido, Japan. The hydrochemical conditions of groundwaters, such as in-situ water pressure, temperature, electric conductivity, pH, redox potential, were monitored without degassing at multiple intervals along the borehole. Groundwater samples were taken periodically and chemical composition was analyzed using ICP-MS, etc. Cell counts were in the range of 103 to 105 cells ml-1. Molecular analyses revealed the spatial distribution and heterogeneity of the microbial population. Abundant methanogens were detected in the groundwater, and 80% of them were related to either Methanoregula boonei or Methanobacterium flexile that can utilize H2/CO2 by methanogenesis. Phylotypes clustered within the phylum Firmicutes, beta-Proteobacteria, delta-Proteobacteria and candidate division TM7 were dominant in the groundwater samples. Laboratory experiments using a culture technique showed that humic substances purified from the groundwater at Horonobe area appear to be degraded by microorganisms. Our results suggest that microbial spatial distributions in the subsurface environment were correlated closely with geochemical conditions, such as redox condition and carbon sources. In addition, it is inferred that humic substances are one of the important carbon sources for the subsurface microbial redox processes in the environment. This study was partly funded by the Ministry of Economy, Trade and Industry of Japan.

  12. Emplacement model of obsidian-rhyolite magma deduced from complete internal section of the Akaishiyama lava, Shirataki, northern Hokkaido, Japan

    Science.gov (United States)

    Wada, K.; Sano, K.

    2016-12-01

    Simultaneously explosive and effusive eruptions of silicic magmas has shed light on the vesiculation and outgassing history of ascending magmas in the conduit and emplacement model of obsidian-rhyolite lavas (Castro et al., 2014; Shipper et al, 2013). As well as the knowledge of newly erupted products such as 2008-2009 Chaitén and 2011-2012 Cordón Caule eruptions, field and micro-textural evidences of well-exposed internal structure of obsidian-rhyolite lava leads to reveal eruption processes of silicic magmas. The Shirataki monogenetic volcano field, 2.2 million year age, northern Hokkaido, Japan, contains many outcrops of obsidian and vesiculated rhyolite zones (SiO2=76.7-77.4 wt.%). Among their outcrops, Akaishiyama lava shows good exposures of internal sections from the top to the bottom along the Kyukasawa valley with thickness of about 190 meters, showing the symmetrical structure comprising a upper clastic zone (UCZ; 5m thick), an upper dense obsidian zone (UDO; 15m), an upper banded obsidian zone (UBO; 70-80m), a central rhyolite zone (CR; 65m), a lower banded obsidian zone (LBO; 15m), a lower dense obsidian zone (LDO; 20m), and a lower clastic zone (LCZ; 3m). The upper banded obsidian zone is characterized by existence of spherulite concentration layers with tuffisite veins and rhyolite enclaves. Spherulites consisting of albite, cristobalaite and obsidian glass, are clustered in the dense obsidian. Tuffisite veins show brecciated obsidians in tuffaceous matrix, showing an outgassing path during the emplacement of obsidian lava. Perpendicular dip of spherulite parallel rows indicates the banded zone itself was the domain of vent area. From the observation of these occurrences in the internal section and rock texture, we show the qualitative formation model of Shirataki obsidian-rhyolite lava.

  13. Diffusivity Models and Greenhouse Gases Fluxes from a Forest, Pasture, Grassland and Corn Field in Northern Hokkaido, Japan

    Institute of Scientific and Technical Information of China (English)

    N.V.NKONGOLO; R.HATANO; V.KAKEMBO

    2010-01-01

    Information on the most influential factors determining gas flux from soils is needed in predictive models for greenhouse gases emissions.We conducted an intensive soil and air sampling along a 2 000 m transect extending from a forest,pasture,grassland and corn field in Shizunai,Hokkaido (Japan),measured CO2,CH4,N2O and NO fluxes and calculated soil bulk density (ρb),air-filled porosity (fa) and total porosity (φ).Using diffusivity models based on either fa alone or on a combination of fa and φ,we predicted two pore space indices:the relative gas diffusion coefficient (Ds/Do) and the pore tortuosity factor (τ).The relationships between pore space indices (Dg/Do and τ) and CO2,CH4,N2O and NO fluxes were also studied.Results showed that the grassland had the highest ρb while fa and φ were the highest in the forest.CO2,CH4,N2O and NO fluxes were the highest in the grassland while N2O dominated in the corn field.Few correlations existed between fa,φ,ρb and gases fluxes while all models predicted that Ds/Do and τ significantly correlated with CO2 and CH4 with correlation coefficient (τ) ranging from 0.20 to 0.80.Overall,diffusivity models based on fa alone gave higher Ds/Do,lower τ and higher R2 and better explained the relationship between pore space indices (Ds/Do and τ) and gases fluxes.Inclusion of Ds/Do and τ in predictive models will improve our understanding of the dynamics of greenhouse gas fluxes from soils.Ds/Do and τ can be easily obtained by measurements of soil air and water and existing diffusivity models.

  14. Reconfigurable L-Band Radar

    Science.gov (United States)

    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.

  15. Quantitative risk assessment of the introduction of rabies into Japan through the illegal landing of dogs from Russian fishing boats in the ports of Hokkaido, Japan.

    Science.gov (United States)

    Kwan, Nigel C L; Ogawa, Hidehito; Yamada, Akio; Sugiura, Katsuaki

    2016-06-01

    Japan has been free from rabies since 1958 and various preventive measures are in place protecting the country from the introduction of the disease. Historical reviews indicate that the illegal landing of dogs from Russian fishing boats in the ports of Hokkaido occurred frequently especially in the early 2000s and this could potentially be a source of introduction of rabies into Japan. The method of scenario tree modelling was used and the following entry and exposure pathway was considered the most likely route of rabies entry: a rabies-infected dog arriving on a Russian fishing boat lands in a port of Hokkaido in Japan, it becomes infectious, contacts and infects a susceptible domestic animal (companion dog, stray dog or wildlife). Input parameter values were based on surveys of Russian fishermen, expert opinion and scientific data from the literature. At present (2006-2015), the probability of the introduction of rabies as a result of one Russian fishing boat arriving at a port of Hokkaido is 8.33×10(-10) (90% Prediction Interval (PI): 7.15×10(-11)-5.34×10(-9)), while this probability would have been 7.70×10(-9) (90% PI: 6.40×10(-10)-4.81×10(-8)) in the past (1998-2005). Under the current situation (average annual number of boat arrivals is 1106), rabies would enter Japan every 1,084,849 (90% PI: 169,215-20,188,348) years, while the disease would have been introduced every 18,309 (90% PI: 2929-220,048) years in the past (average annual number of boat arrivals is 7092). The risk of rabies introduction has decreased 59 fold due to both the effective control of the issue of illegal landing of dogs and the decline in the number of Russian boat arrivals. Control efforts include education of Russian fishermen, establishment of warning signs, daily patrols and regular port surveillance of potential dog landing activity. Furthermore, scenario analysis revealed that the policy of mandatory domestic dog vaccination does not contribute effectively to Japan's rabies

  16. Data on the weights, specific gravities and chemical compositions of potato (Solanum tuberosum tubers for food processing from different areas of Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    Hiroaki Sato

    2017-04-01

    Full Text Available This data article provides the weights, specific gravities and chemical compositions (moisture, protein, fat, ash, and carbohydrate of potato tubers, for food processing use, from the Tokachi, Kamikawa and Abashiri areas of Hokkaido, Japan. Potato tubers of four cultivars (‘Toyoshiro’, ‘Kitahime’, ‘Snowden’ and ‘Poroshiri’ were employed in the current study. The weights and specific gravities of potato tubers from each cultivar, harvested from three areas, were measured, and those of near average weight and specific gravity from each group were analyzed for their chemical composition. In this article, weight, specific gravity, and chemical composition data are provided in tables.

  17. Spatial variation in tree seedling density after the site preparation for planting in a cleared coniferous plantation in Hokkaido, northern Japan

    OpenAIRE

    Shin, ChangSeob; Shibuya, Masato

    2007-01-01

    To study spatial variation in natural tree seedling density and the relationship between variation in seedling density and seed dispersal mode at a cleared site, we surveyed natural tree seedlings after the site preparation for planting in a coniferous plantation cleared by a typhoon disturbance in 2004. The site was located near Sikotsuko Lake, Hokkaido, northern Japan. Twenty-five tree seedling species were found and the mean seedling density was 9.8 seedlings/m2. Seedlings of non-animal-di...

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

    Science.gov (United States)

    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.

  19. Radar foundations for imaging and advanced concepts

    CERN Document Server

    Sullivan, Roger

    2004-01-01

    Through courses internally taught at IDA, Dr. Roger Sullivan has devised a book that brings readers fully up to speed on the most essential quantitave aspects of general radar in order to introduce study of the most exciting and relevant applications to radar imaging and advanced concepts: Synthetic Aperture Radar (4 chapters), Space-time Adaptive Processing, moving target indication (MTI), bistatic radar, low probability of intercept (LPI) radar, weather radar, and ground-penetrating radar. Whether you're a radar novice or experienced professional, this is an essential refer

  20. Broadview Radar Altimetry Toolbox

    Science.gov (United States)

    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

  1. Direct determination of IMF B-Y-related cusp current systems, using SuperDARN radar and multiple ground magnetometer data: A link to theory on cusp current origin

    DEFF Research Database (Denmark)

    Amm, O.; Engebretson, M.J.; Greenwald, R.A.

    1999-01-01

    , respectively, with magnitudes of around 0.5 A/km(2). The geometry of the current system resembles a DPY current system [Friis-Christensen and Wilhjelm, 1975]. Using our results, we test alternative theories on cusp current origin that lead to different predictions of the relative location of the cusp current...... system with respect to the open-closed field line boundary. The location of this boundary is inferred from DMSP F10 satellite data. The center of our resulting current system is located clearly poleward of the open-closed field line boundary, thus favoring the idea of Lee et al. [1985] that the cusp FACs...... are caused by a rotational discontinuity of the magnetic field at the magnetopause. In contrast, the idea of Clauer and Banks [1986] that a mapping of the solar wind E-z component to the ionosphere is responsible for the cusp current system is not supported....

  2. A Real-Time Nowcast/Forecast System for Radar Electrojet Clutter Driven by Global Assimilative Models of the Ionosphere

    Science.gov (United States)

    Carrano, C. S.; Alcala, C. M.; Liang, P.; Groves, K. M.; Donatelli, D. E.; Daniell, R. E.

    2006-12-01

    -region. This deficiency is particularly pronounced during geomagnetic storm activity, when the ionospheric response deviates most from climatological behavior. The latest version of the SBR-IES tool can accept, as input, real-time specifications of the ionosphere provided by global assimilative models (e.g. PRISM or GAIM) that are currently or soon to be in operational use at AFWA. Forecasts of radar clutter can be generated using forecasts of the ionospheric state provided by the Ionospheric Forecast Model (IFM), for example. In the near future we plan to include the high resolution specification of the electric field provided by the real-time incoherent scatter radars of the Super Dual Auroral Radar Network (SuperDARN). It is expected that the use of data assimilative models to provide the background ionospheric densities, temperatures, and electric field will lead to substantially more accurate and high resolution predictions of radar electrojet clutter. Moreover, these improvements can be made without sacrificing real-time impact assessment requirements.

  3. Weather Radar Technology Development

    Science.gov (United States)

    1990-08-15

    Preparation). MISCELLANEOUS Donaldson Jr, R.J., 1987: "Significance of the 40th Anniversary Conference." Address at the Battan Memorial and 40th Anni - versary...Bergen and Albers (1987). They have achieved -37 -29 -25 -6 4 7 magnificent results for reducing general -35 -28 -19 -7 -3 4 ambiguity. 283 284 285 3.2... Albers , 1988: Two- and the National Severe Storms Laboratory S-band three-dimensional de-aliasing of Doppler radar in Norman, Oklahoma. For three

  4. Thermoluminescence dating of a tephra deposit of the ''Toya'' volcano (Hokkaido, Japan); Datation par thermoluminescence d'un niveau de tephra du volcan ''Toya'' (Hokkaido, Japon)

    Energy Technology Data Exchange (ETDEWEB)

    Sanzelle, S.; Pilleyre, Th.; Miallier, D.; Fain, J. [Universite Blaise Pascal, Clermont-Ferrand II, (CNRS), Lab. de Physique Corpusculaire, 63 - Aubiere (France); Ganzawa, Y. [Hokkaido Univ. of Education, Hakodate (Japan)

    2000-07-01

    Toya caldera which has a diameter of about 10 km and a hexagonal form is situated in the southern part of Hokkaido, northern Japan. The water level of the caldera lake is 84 m and the highest altitude of the central dome in the lake, Nakajima is 454 m. The volcanic activity is divided into 4 stages of the Toya Pyroclastic Flow Deposits 1 to 4. This tephra is composed of rhyolitic ash which is rich in glass and associated with hornblende, pyroxene and quartz. In a previous work, the age of eruption was estimated by utilising several dating methods and the stratigraphical correlation with other tephra. The ages which resulted from FT (Fission Tracks) dating and TL (Thermoluminescence) dating indicated 130{+-}30 ka and 103-134 ka, respectively. The overall estimated age, received from other information such as the environmental change of mineral marine deposits, has been accepted as 100-120 ka by Quaternary Researchers. Because this tephra can be found widely in the Quaternary field, many researchers can use it as an appropriate age indicator of the 5c or 5d Isotope Stage, the middle age of the Last Internal Glacial Age. A new dating program was initiated, using the red TL of quartz grains extracted from the tephra. The samples studied in the present work came from the southern part of the deposits, around 15 km away from the centre of the caldera. The TL measurements, using the red signal of xenolithic quartz grains from the tephra, were made at Aubiere. Three distinct sets of samples were measured. The first two differ from each other by grain size, 250-350 {mu}m (TOYA2, Aset2) and 150-250 {mu}m (TOYA1,Bset3), and were irradiated in Japan and the third one, 250-350 {mu}m (TOYA2, Cset2) was irradiated at Aubiere. The annual dose rate experienced by the samples during burial was estimated from a compilation of radionuclide contents evaluated in Japan using NAA and in France, using low level gamma spectroscopy (Aubiere) and ICPMS (CRPG, Nancy). In situ water content

  5. Terahertz radar cross section measurements

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

    2010-01-01

    We perform angle- and frequency-resolved radar cross section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional radar...

  6. Performance indicators modern surveillance radar

    NARCIS (Netherlands)

    Nooij, P.N.C.; Theil, A.

    2014-01-01

    Blake chart computations are widely employed to rank detection coverage capabilities of competitive search radar systems. Developed for comparable 2D radar systems with a mechanically rotating reflector antenna, it was not necessary to regard update rate and plot quality in Blake's chart. To

  7. Measuring human behaviour with radar

    NARCIS (Netherlands)

    Dorp, Ph. van

    2001-01-01

    The paper presents human motion measurements with the experimental Frequency Modulated Continuous Wave(FMCW) radar at TNO-FEL. The aim of these measurements is to analyse the Doppler velocity spectrum of humans. These analysis give insight in measuring human behaviour with radar for security applica

  8. Behavior Subtraction applied to radar

    NARCIS (Netherlands)

    Rossum, W.L. van; Caro Cuenca, M.

    2014-01-01

    An algorithm developed for optical images has been applied to radar data. The algorithm, Behavior Subtraction, is based on capturing the dynamics of a scene and detecting anomalous behavior. The radar application is the detection of small surface targets at sea. The sea surface yields the expected s

  9. Imaging with Synthetic Aperture Radar

    CERN Document Server

    Massonnet, Didier

    2008-01-01

    Describing a field that has been transformed by the recent availability of data from a new generation of space and airborne systems, the authors offer a synthetic geometrical approach to the description of synthetic aperture radar, one that addresses physicists, radar specialists, as well as experts in image processing.  

  10. Performance indicators modern surveillance radar

    NARCIS (Netherlands)

    Nooij, P.N.C.; Theil, A.

    2014-01-01

    Blake chart computations are widely employed to rank detection coverage capabilities of competitive search radar systems. Developed for comparable 2D radar systems with a mechanically rotating reflector antenna, it was not necessary to regard update rate and plot quality in Blake's chart. To charact

  11. Synthetic Aperture Radar - Hardware Development

    Directory of Open Access Journals (Sweden)

    V. Rosner

    2009-06-01

    Full Text Available Experimental real and synthetic aperture radar are developed from the base-band digital unit to the analogue RF parts, based on solid state units, using pulse compression for radar imaging. Proper QPSK code is found for matched filter.

  12. Radar image registration and rectification

    Science.gov (United States)

    Naraghi, M.; Stromberg, W. D.

    1983-01-01

    Two techniques for radar image registration and rectification are presented. In the registration method, a general 2-D polynomial transform is defined to accomplish the geometric mapping from one image into the other. The degree and coefficients of the polynomial are obtained using an a priori found tiepoint data set. In the second part of the paper, a rectification procedure is developed that models the distortion present in the radar image in terms of the radar sensor's platform parameters and the topographic variations of the imaged scene. This model, the ephemeris data and the digital topographic data are then used in rectifying the radar image. The two techniques are then used in registering and rectifying two examples of radar imagery. Each method is discussed as to its benefits, shortcomings and registration accuracy.

  13. A radar image time series

    Science.gov (United States)

    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.

  14. 100 years of radar

    CERN Document Server

    Galati, Gaspare

    2016-01-01

    This book offers fascinating insights into the key technical and scientific developments in the history of radar, from the first patent, taken out by Hülsmeyer in 1904, through to the present day. Landmark events are highlighted and fascinating insights provided into the exceptional people who made possible the progress in the field, including the scientists and technologists who worked independently and under strict secrecy in various countries across the world in the 1930s and the big businessmen who played an important role after World War II. The book encourages multiple levels of reading. The author is a leading radar researcher who is ideally placed to offer a technical/scientific perspective as well as a historical one. He has taken care to structure and write the book in such a way as to appeal to both non-specialists and experts. The book is not sponsored by any company or body, either formally or informally, and is therefore entirely unbiased. The text is enriched by approximately three hundred ima...

  15. Evaluating renewable natural resources flow and net primary productivity with a GIS-Emergy approach: A case study of Hokkaido, Japan

    Science.gov (United States)

    Wang, Chengdong; Zhang, Shenyan; Yan, Wanglin; Wang, Renqing; Liu, Jian; Wang, Yutao

    2016-11-01

    Renewable natural resources, such as solar radiation, rainfall, wind, and geothermal heat, together with ecosystem services, provide the elementary supports for the sustainable development of human society. To improve regional sustainability, we studied the spatial distributions and quantities of renewable natural resources and net primary productivity (NPP) in Hokkaido, which is the second largest island of Japan. With the help of Geographic Information System (GIS) software, distribution maps for each type of renewable natural resource were generated by kriging interpolation based on statistical records. A composite map of the flow of all types of renewable natural resources was also generated by map layer overlapping. Additionally, we utilized emergy analysis to convert each renewable flow with different attributes into a unified unit (i.e., solar equivalent joules [sej]). As a result, the spatial distributions of the flow of renewable natural resources of the Hokkaido region are presented in the form of thematic emergy maps. Thus, the areas with higher renewable emergy can be easily visualized and identified. The dominant renewable flow in certain areas can also be directly distinguished. The results can provide useful information for regional sustainable development, environmental conservation and ecological management.

  16. Evaluating renewable natural resources flow and net primary productivity with a GIS-Emergy approach: A case study of Hokkaido, Japan.

    Science.gov (United States)

    Wang, Chengdong; Zhang, Shenyan; Yan, Wanglin; Wang, Renqing; Liu, Jian; Wang, Yutao

    2016-11-18

    Renewable natural resources, such as solar radiation, rainfall, wind, and geothermal heat, together with ecosystem services, provide the elementary supports for the sustainable development of human society. To improve regional sustainability, we studied the spatial distributions and quantities of renewable natural resources and net primary productivity (NPP) in Hokkaido, which is the second largest island of Japan. With the help of Geographic Information System (GIS) software, distribution maps for each type of renewable natural resource were generated by kriging interpolation based on statistical records. A composite map of the flow of all types of renewable natural resources was also generated by map layer overlapping. Additionally, we utilized emergy analysis to convert each renewable flow with different attributes into a unified unit (i.e., solar equivalent joules [sej]). As a result, the spatial distributions of the flow of renewable natural resources of the Hokkaido region are presented in the form of thematic emergy maps. Thus, the areas with higher renewable emergy can be easily visualized and identified. The dominant renewable flow in certain areas can also be directly distinguished. The results can provide useful information for regional sustainable development, environmental conservation and ecological management.

  17. Effects of a windthrow disturbance on the carbon balance of a broadleaf deciduous forest in Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    K. Yamanoi

    2015-12-01

    Full Text Available Forests play an important role in the terrestrial carbon balance, with most being in a carbon sequestration stage. The net carbon releases that occur result from forest disturbance, and windthrow is a typical disturbance event affecting the forest carbon balance in eastern Asia. The CO2 flux has been measured using the eddy covariance method in a deciduous broadleaf forest (Japanese white birch, Japanese oak, and castor aralia in Hokkaido, where incidental damage by the strong Typhoon Songda in 2004 occurred. We also used the biometrical method to demonstrate the CO2 flux within the forest in detail. Damaged trees amounted to 40 % of all trees, and they remained on site where they were not extracted by forest management. Gross primary production (GPP, ecosystem respiration (Re, and net ecosystem production were 1350, 975, and 375 g C m−2 yr−1 before the disturbance and 1262, 1359, and −97 g C m−2 yr−1 2 years after the disturbance, respectively. Before the disturbance, the forest was an evident carbon sink, and it subsequently transformed into a net carbon source. Because of increased light intensity at the forest floor, the leaf area index and biomass of the undergrowth (Sasa kurilensis and S. senanensis increased by factors of 2.4 and 1.7, respectively, in 3 years subsequent to the disturbance. The photosynthesis of Sasa increased rapidly and contributed to the total GPP after the disturbance. The annual GPP only decreased by 6 % just after the disturbance. On the other hand, the annual Re increased by 39 % mainly because of the decomposition of residual coarse-wood debris. The carbon balance after the disturbance was controlled by the new growth and the decomposition of residues. The forest management, which resulted in the dead trees remaining at the study site, strongly affected the carbon balance over the years. When comparing the carbon uptake efficiency at the study site with that at others, including those with various kinds

  18. Explosive eruptive activity and temporal magmatic changes at Yotei Volcano during the last 50,000 years, southwest Hokkaido, Japan

    Science.gov (United States)

    Uesawa, Shimpei; Nakagawa, Mitsuhiro; Umetsu, Akane

    2016-10-01

    To understand the eruptive history, structure, and magmatic evolution of Yotei Volcano, southwest Hokkaido, Japan, we investigated the geology and petrology of tephras located around the base of the volcano. We identified 43 tephra units interbedded with soils (in descending stratigraphic order, tephras Y1-Y43), and four widespread regional tephras. Ten radiocarbon ages were obtained from soils beneath the Yotei tephras. On the basis of petrologic differences and, the stratigraphic positions of thick layers of volcanic ash soil, indicative of volcanic stratigraphic gaps, the Yotei tephras are divided into four groups (in ascending stratigraphic order): Yotei tephra groups I, II-1, II-2, and II-3. We calculated the age of each eruptive deposit based on the soil accumulation rate, and estimated the volume of each eruption using isopach maps or the correlation between eruption volume and the maximum thickness at ~ 10 km from the summit crater. The results regarding eruptive activity and the rate of explosive eruptions indicate four eruptive stages at Yotei Volcano over the last 50,000 years. Stage I eruptions produced Yotei tephra group I between ca. 54 cal. ka BP and up to at least ca. 46 cal. ka BP, at relatively high average eruption rates of 0.07 km3 dense-rock equivalent (DRE)/ky. After a pause in activity of ca. 8000 years, Stage II-1 to II-2 eruptions produced Yotei tephra groups II-1 and II-2 from ca. 38 to ca. 21 cal. ka BP at high average eruption rates (0.10 km3 DRE/ky), after a pause in activity of 2000-3000 years. Finally, after another pause in activity of 4000-5000 years, Stage II-3 eruptions produced Yotei tephra group II-3 from ca. 16.5 cal. ka BP until the present day, at low average eruption rates (0.009 km3 DRE/ky). Whole-rock geochemical compositions vary within each tephra group over the entire eruption history. For example, group I and II-3 tephras contain the lowest and highest abundances, respectively, of K2O, P2O5, and Zr. Group II-1 has the

  19. Radar signature acquisition using an indigenously designed noise radar system

    Science.gov (United States)

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

    2011-06-01

    A new design of a noise radar system is proposed with capabilities to measure and acquire the radar signature of various targets. The proposed system can cover a noise bandwidth of near DC to 30 GHz. The noise radar signature measurements were conducted for selective targets like spheres and carpenter squares with and without dielectric bodies for a noise band of 400MHz-3000MHz. The bandwidth of operation was limited by the multiplier and the antennae used. The measured results of the target signatures were verified with the simulation results.

  20. The use of radar for bathymetry assessment

    NARCIS (Netherlands)

    Aardoom, J.H.; Greidanus, H.S.F.

    1998-01-01

    The bottom topography in shallow seas can be observed by air- and spaceborne imaging radar. Bathymetric information derived from radar data is limited in accuracy, but radar has a good spatial coverage. The accuracy can be increased by assimilating the radar imagery into existing or insitu gathered

  1. Radar, Insect Population Ecology, and Pest Management

    Science.gov (United States)

    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.

  2. The use of radar for bathymetry assessment

    NARCIS (Netherlands)

    Aardoom, J.H.; Greidanus, H.S.F.

    1998-01-01

    The bottom topography in shallow seas can be observed by air- and spaceborne imaging radar. Bathymetric information derived from radar data is limited in accuracy, but radar has a good spatial coverage. The accuracy can be increased by assimilating the radar imagery into existing or insitu gathered

  3. Radar signal analysis and processing using Matlab

    CERN Document Server

    Mahafza, Bassem R

    2008-01-01

    Offering radar-related software for the analysis and design of radar waveform and signal processing, this book provides comprehensive coverage of radar signals and signal processing techniques and algorithms. It contains numerous graphical plots, common radar-related functions, table format outputs, and end-of-chapter problems. The complete set of MATLAB[registered] functions and routines are available for download online.

  4. Large phased-array radars

    Science.gov (United States)

    Brookner, Eli, Dr.

    1988-12-01

    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.

  5. Air and spaceborne radar systems an introduction

    CERN Document Server

    Lacomme, Philippe; Hardange, Jean-Philippe; Normant, Eric

    2001-01-01

    A practical tool on radar systems that will be of major help to technicians, student engineers and engineers working in industry and in radar research and development. The many users of radar as well as systems engineers and designers will also find it highly useful. Also of interest to pilots and flight engineers and military command personnel and military contractors. """"This introduction to the field of radar is intended for actual users of radar. It focuses on the history, main principles, functions, modes, properties and specific nature of modern airborne radar. The book examines radar's

  6. Signal processing in noise waveform radar

    CERN Document Server

    Kulpa, Krzysztof

    2013-01-01

    This book is devoted to the emerging technology of noise waveform radar and its signal processing aspects. It is a new kind of radar, which use noise-like waveform to illuminate the target. The book includes an introduction to basic radar theory, starting from classical pulse radar, signal compression, and wave radar. The book then discusses the properties, difficulties and potential of noise radar systems, primarily for low-power and short-range civil applications. The contribution of modern signal processing techniques to making noise radar practical are emphasized, and application examples

  7. Under the Radar

    CERN Document Server

    Goss, WM

    2010-01-01

    This is the biography of Ruby Payne-Scott (1912 to 1981). As the first female radio astronomer (and one of the first people in the world to consider radio astronomy), she made classic contributions to solar radio physics. She also played a major role in the design of the Australian government's Council for Scientific and Industrial Research radars, which were in turn of vital importance in the Southwest Pacific Theatre in World War II and were used by Australian, US and New Zealand personnel. From a sociological perspective, her career also offers many examples of the perils of being a female academic in the first half of the 20th century. Written in an engaging style and complemented by many historical photographs this book gives a fascinating insight into the beginning of radio astronomy and the role of a pioneering woman in astronomy.

  8. Gyroklystron-Powered WARLOC Radar

    Science.gov (United States)

    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.

  9. 77 HHz radar for automobile

    Directory of Open Access Journals (Sweden)

    O. M. Lyashuk

    2012-02-01

    Full Text Available Modern requirements to safety and comfort of drivers and passengers of a car cause continuous development of corresponding technical facilities. Technologies that provide implementation of these requirements are on the first place for the developers of cars. One of the most important requirement is an analysis of road situation, where various sensors are used. One of them is radar. Principle of action, basic parameters and application of radar RS-200 is considered in this article. Radar is used in modern cars of brand Mersedes Benz and works on frequency 77 HHz. It uses the LFM (linear frequency modulation with the programmatic setting of resolution for distance.

  10. Introduction to radar target recognition

    CERN Document Server

    Tait, P

    2006-01-01

    This new text provides an overview of the radar target recognition process and covers the key techniques being developed for operational systems. It is based on the fundamental scientific principles of high resolution radar, and explains how the techniques can be used in real systems, taking into account the characteristics of practical radar system designs and component limitations. It also addresses operational aspects, such as how high resolution modes would fit in with other functions such as detection and tracking. Mathematics is kept to a minimum and the complex techniques and issues are

  11. Space noise synthetic aperture radar

    Science.gov (United States)

    Kulpa, Krzysztof S.

    2006-03-01

    The paper presents limitations of space borne synthetic aperture radars, caused by range and Doppler velocity ambiguities, and the concept of usage of the noise radar technology for creation of high-resolution space SAR images. The noise SAR is free from limitation caused by the periodicity of pulse waveform ambiguity function, and therefore this technology can be used in the future space missions. The basic concept of noise SAR image formation is also presented. The image formation algorithm has been verified using the simulated data produced by Raw Radar Data Simulator.

  12. Coordinated Radar Resource Management for Networked Phased Array Radars

    Science.gov (United States)

    2014-12-01

    computed, and the detection of a target is determined based on a Monte Carlo test. For each successful target confirmation, a measurement report is...detection based on Monte Carlo test • add appropriate random perturbations to detec- tion measurements Radar Targets Environment Input Parameters... Fuente and J.R. Casar-Corredera. Optimal radar pulse scheduling using a neural network. In IEEE Int. Conf. Neural Networks, volume 7, pages 4558–4591

  13. Compressive Sensing for MIMO Radar

    CERN Document Server

    Yu, Yao; Poor, H Vincent

    2009-01-01

    Multiple-input multiple-output (MIMO) radar systems have been shown to achieve superior resolution as compared to traditional radar systems with the same number of transmit and receive antennas. This paper considers a distributed MIMO radar scenario, in which each transmit element is a node in a wireless network, and investigates the use of compressive sampling for direction-of-arrival (DOA) estimation. According to the theory of compressive sampling, a signal that is sparse in some domain can be recovered based on far fewer samples than required by the Nyquist sampling theorem. The DOA of targets form a sparse vector in the angle space, and therefore, compressive sampling can be applied for DOA estimation. The proposed approach achieves the superior resolution of MIMO radar with far fewer samples than other approaches. This is particularly useful in a distributed scenario, in which the results at each receive node need to be transmitted to a fusion center for further processing.

  14. Air Defense Radar Operations Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of laboratories, experimental test equipment including state-of-theart test bed radar, and test ranges. The facilities are used to design, develop,...

  15. Air Defense Radar Operations Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of laboratories, experimental test equipment including state-of-theart test bed radar, and test ranges. The facilities are used to design, develop,...

  16. Characterization of a non-pathogenic H5N1 influenza virus isolated from a migratory duck flying from Siberia in Hokkaido, Japan, in October 2009

    Directory of Open Access Journals (Sweden)

    Okamatsu Masatoshi

    2011-02-01

    Full Text Available Abstract Background Infection with H5N1 highly pathogenic avian influenza viruses (HPAIVs of domestic poultry and wild birds has spread to more than 60 countries in Eurasia and Africa. It is concerned that HPAIVs may be perpetuated in the lakes in Siberia where migratory water birds nest in summer. To monitor whether HPAIVs circulate in migratory water birds, intensive surveillance of avian influenza has been performed in Mongolia and Japan in autumn each year. Until 2008, there had not been any H5N1 viruses isolated from migratory water birds that flew from their nesting lakes in Siberia. In autumn 2009, A/mallard/Hokkaido/24/09 (H5N1 (Mal/Hok/24/09 was isolated from a fecal sample of a mallard (Anas platyrhynchos that flew from Siberia to Hokkaido, Japan. The isolate was assessed for pathogenicity in chickens, domestic ducks, and quails and analyzed antigenically and phylogenetically. Results No clinical signs were observed in chickens inoculated intravenously with Mal/Hok/24/09 (H5N1. There was no viral replication in chickens inoculated intranasally with the isolate. None of the domestic ducks and quails inoculated intranasally with the isolate showed any clinical signs. There were no multiple basic amino acid residues at the cleavage site of the hemagglutinin (HA of the isolate. Each gene of Mal/Hok/24/09 (H5N1 is phylogenetically closely related to that of influenza viruses isolated from migratory water birds that flew from their nesting lakes in autumn. Additionally, the antigenicity of the HA of the isolate was similar to that of the viruses isolated from migratory water birds in Hokkaido that flew from their northern territory in autumn and different from those of HPAIVs isolated from birds found dead in China, Mongolia, and Japan on the way back to their northern territory in spring. Conclusion Mal/Hok/24/09 (H5N1 is a non-pathogenic avian influenza virus for chickens, domestic ducks, and quails, and is antigenically and genetically

  17. SMAP RADAR Calibration and Validation

    Science.gov (United States)

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

    2015-12-01

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

  18. Haystack Ultrawideband Satellite Imaging Radar

    Science.gov (United States)

    2014-09-01

    enable long-range imaging. In 2013, a major upgrade to the facility was completed, adding a millimeter - wave W-band radar capability to Haystack’s X...diameter antenna was completely rebuilt to provide a 100 μm root-mean-square (rms) surface accuracy to support operation at the 3 mm wave - length (W...electromagnetic wave propagation through the troposphere. − The signal processing system lev- eraged Lincoln Laboratory‘s Radar Open Systems

  19. Alternatives for Military Space Radar

    Science.gov (United States)

    2007-01-01

    Because the characteristics and performance of Discov- erer II’s radar are well documented, CBO based the design of its notional Space Radar on that of...2005, report to accompany H.R. 4613, Report 108-553 (June 18, 2004). 13. Air Force Space and Missile Systems Center, “Fact Sheet: Discov- erer II...360-degree coverage in GMTI mode. See Federation of American Scientists, Space Policy Project, “Discov- erer II STARLITE” (January 24, 2000

  20. Coded continuous wave meteor radar

    Science.gov (United States)

    Chau, J. L.; Vierinen, J.; Pfeffer, N.; Clahsen, M.; Stober, G.

    2016-12-01

    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, such as wind fields. This type of a radar would also be useful for over-the-horizon radar, ionosondes, and observations of field-aligned-irregularities.

  1. Radar Imaging and Target Identification

    Science.gov (United States)

    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

  2. Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR)

    Science.gov (United States)

    2013-06-01

    performance in complex scenarios. Among these scenarios are ground penetrating radar and forward-looking radar for landmine and improvised explosive...Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR) by Traian Dogaru ARL-TN-0548 June 2013...2013 Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR) Traian Dogaru Sensors and Electron

  3. Coded continuous wave meteor radar

    Science.gov (United States)

    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.

  4. Chemical deicer poisoning was suspected as a cause of the 2005-2006 wintertime mortality of small wild birds in Hokkaido.

    Science.gov (United States)

    Tanaka, Tomohisa; Tanoue, Ginpei; Yamasaki, Masahiro; Takashima, Ikuo; Sakoda, Yoshihiro; Ochiai, Kenji; Umemura, Takashi

    2008-06-01

    Many small wild birds died in the 2005-2006 wintertime in Hokkaido. Thirteen birds were pathologically examined and it was attempted to detect West Nile and influenza viruses from their organs. Consecutive pathological changes were fresh hemorrhage and acute circulatory failure. Viral detections were negative. Selective occurrence in wintertime, literature review and the results of pathological and virological examinations suggested chemical deicer poisoning as the cause of wild bird death. Chicks treated orally with deicer showed acute death and their pathological changes were similar to those of the wild birds. Because the chicks showed significant elevation of plasma Na concentration, plasma electrolyte analysis of the affected wild birds might be crucial to confirm our tentative diagnosis.

  5. Characteristics of postseismic deformation following the 2003 Tokachi-oki earthquake and estimation of the viscoelastic structure in Hokkaido, northern Japan

    Science.gov (United States)

    Itoh, Yuji; Nishimura, Takuya

    2016-09-01

    Postseismic deformation of the 2003 Tokachi-oki earthquake ( M w 8.0) has been observed by GNSS. We analyzed the deformation observed in Hokkaido in the 2nd to the 7th year following the 2003 Tokachi-oki earthquake and examined the effect of two major mechanisms (i.e., afterslip and viscoelastic relaxation) for the observed postseismic deformation by fitting it with a model consisting of afterslip and viscoelastic relaxation. The thickness of the lithosphere, the viscosity of the asthenosphere, and the time decaying constant of afterslip were estimated to be 50 km, 2.0 × 1019 Pa s, and 0.110 year, respectively, which are concordant with those in the Tohoku region estimated in previous studies. The revealed characteristics of postseismic deformation are as follows. At most of the used stations, afterslip played the dominant role in the 2nd year and was still sustained near the coseismic area even in the 7th year. However, the calculated velocity due to viscoelastic relaxation was comparable to that due to afterslip at the stations in northern Hokkaido after the 5th year. Because the calculated velocity due to viscoelastic relaxation was landward near the coseismic slip area, afterslip near the coseismic slip area will be biased to be smaller if viscoelastic relaxation is ignored. A systematic spatial pattern of the residuals considering afterslip only highlights an importance for explaining the observation data. We also examined the effect of viscoelastic relaxation due to afterslip for the parameter estimation and found that it was too small to affect the estimated structure parameters.[Figure not available: see fulltext.

  6. Landscape patterns of overstory litterfall and related nutrient fluxes in a cool-temperate forest watershed in northern Hokkaido,Japan

    Institute of Scientific and Technical Information of China (English)

    XU Xiao-niu; Hideaki SHIBATA

    2007-01-01

    Within a forested watershed at the Uryu Experimental Forest of Hokkaido University in northern Hokkaido, overstory litterfall and related nutrient fluxes were measured at different landscape zones over two years. The wetland zone covered with Picea glehnii pure stand. The riparian zone was deciduous broad-leaved stand dominated by Alnus hirsuta and Salix spp., while the mixture of deciduous broadleaf and evergreen conifer dominated by Betula platyphylla, Quercus crispula and Abies sachalinensis distributed on the upland zone.Annual litterfall averaged 1444, 5122, and 4123 kg·hm-2·a-1 in the wetland, riparian and upland zones, respectively. Litterfall production peaked in September-ctober,and foliage litter contributed the greatest amount (73.4%-87.6 %) of the annual total litterfall. Concentrations of nutrients analyzed in foliage litter of the dominant species showed a similar seasonal variation over the year except for N in P. Glehnii and A. Hirsuta. The nutrient fluxes for all elements analyzed were greatest on riparian zone and lowest in wetland zone. Nutrient fluxes via lit terfall followed the decreasing sequence: N (11-129 kg·hm-2·a-1) > Ca (9-69) > K (5-20) > Mg (3-15) > P (0.4-4.7) for all stands. Significant differences were found in litterfall production and nutrient fluxes among the different landscape components. There existed significantdif ferences in soil chemistry between the different landscape zones. The consistently low soil C:N ratios at the riparian zone might be due to the higher-quality litter inputs (largely N-fixing alder).

  7. Brachylaima ezohelicis sp. nov. (Trematoda: Brachylaimidae) found from the land snail Ezohelix gainesi, with a note of an unidentified Brachylaima species in Hokkaido, Japan.

    Science.gov (United States)

    Nakao, Minoru; Waki, Tsukasa; Sasaki, Mizuki; Anders, Jason L; Koga, Daisuke; Asakawa, Mitsuhiko

    2017-06-01

    In the Japanese Archipelago, Ezohelix gainesi, a member of bradybaenid land snails, is endemic mainly to the island of Hokkaido. During July to August of 2016, a survey to detect trematode infections from E. gainesi was carried out at a forest city park in Asahikawa, Hokkaido. Systemic infections of the snails with sporocysts containing short-tailed cercariae were found in 5.3% of 94 individuals examined. Furthermore, most of them (90.4%) harbored non-encysted metacercariae within their kidneys. A DNA sequence identification revealed that both of the sporocyst and the metacercaria belong to an unknown species of the family Brachylaimidae. The metacercariae showed a genetic diversity with 6 haplotypes of mitochondrial DNA (mtDNA) even in the limited sampling area. A definitive host of the unknown species could not be determined, although 34 field mice (Apodemus speciosus) and 21 voles (Myodes rufocanus) from the city park were examined for intestinal parasites. To examine the adult stage, the metacercariae were perorally administrated to mice, together with anti-inflammatory treatment with methylprednisolone. Fully matured adult worms were recovered from the intestinal ileum 8 and 14days postinfection. The gravid adults showed typical features of the genus Brachylaima. A morphological and biogeographical evaluation prompted us to propose Brachylaima ezohelicis sp. nov. for the parasite from E. gainesi. The autochthony of the first intermediate host and the spatial heterogeneity of mtDNA suggest that the new species found in the city park is not a recently expanded population of immigrant origin. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. HPRF pulse Doppler stepped frequency radar

    Institute of Scientific and Technical Information of China (English)

    LONG Teng; REN LiXiang

    2009-01-01

    Stepped frequency radar Is a well known scheme to generate high range resolution profile (HRRP) of targets. Through appropriate radar parameter design, the radar enables both unambiguous velocity measurement and high resolution ranging within a single dwell in a high pulse repetition frequency (HPRF) mode. This paper analyzes in detail the design principle of the HPRF stepped frequency radar system, the solution to its ambiguity issue, as well as its signal processing method. Both theoretical analysis and simulation results demonstrate that the proposed radar scheme can work independently to solve the problem of motion compensation, and is therefore highly applicable to many new types of radar.

  9. Adaptive filters applied on radar signals

    OpenAIRE

    2013-01-01

    This master thesis has been performed at SAAB AB in Järfälla, Sweden.A radar warning receiver must alert the user when someone highlights it with radarsignals. Radar signals used today varies and has a wide frequency band. In order todetect all possible radar signals the radar warning receiver must have a widebandwidth. This results in that the noise power will be high in the radar warningreceiver and weak radar signals will be hard to detect or even undetected.The aim of the thesis work was ...

  10. First simultaneous observations of flux transfer events at the high-latitude magnetopause by the Cluster spacecraft and pulsed radar signatures in the conjugate ionosphere by the CUTLASS and EISCAT radars

    Directory of Open Access Journals (Sweden)

    J. A. Wild

    Full Text Available Cluster magnetic field data are studied during an outbound pass through the post-noon high-latitude magnetopause region on 14 February 2001. The onset of several minute perturbations in the magnetospheric field was observed in conjunction with a southward turn of the interplanetary magnetic field observed upstream by the ACE spacecraft and lagged to the subsolar magnetopause. These perturbations culminated in the observation of four clear magnetospheric flux transfer events (FTEs adjacent to the magnetopause, together with a highly-structured magnetopause boundary layer containing related field features. Furthermore, clear FTEs were observed later in the magnetosheath. The magnetospheric FTEs were of essentially the same form as the original "flux erosion events" observed in HEOS-2 data at a similar location and under similar interplanetary conditions by Haerendel et al. (1978. We show that the nature of the magnetic perturbations in these events is consistent with the formation of open flux tubes connected to the northern polar ionosphere via pulsed reconnection in the dusk sector magnetopause. The magnetic footprint of the Cluster spacecraft during the boundary passage is shown to map centrally within the fields-of-view of the CUTLASS SuperDARN radars, and to pass across the field-aligned beam of the EISCAT Svalbard radar (ESR system. It is shown that both the ionospheric flow and the backscatter power in the CUTLASS data pulse are in synchrony with the magnetospheric FTEs and boundary layer structures at the latitude of the Cluster footprint. These flow and power features are subsequently found to propagate poleward, forming classic "pulsed ionospheric flow" and "poleward-moving radar auroral form" structures at higher latitudes. The combined Cluster-CUTLASS observations thus represent a direct demonstration of the coupling of momentum and energy into the magnetosphere-ionosphere system via pulsed magnetopause reconnection. The ESR

  11. Coded continuous wave meteor radar

    Directory of Open Access Journals (Sweden)

    J. Vierinen

    2015-07-01

    Full Text Available The concept of coded continuous wave meteor radar is introduced. The radar uses a continuously transmitted pseudo-random waveform, which has several advantages: coding avoids range aliased echoes, which are often seen with commonly used pulsed specular meteor radars (SMRs; continuous transmissions maximize pulse compression gain, allowing operation with significantly lower peak transmit power; the temporal resolution can be changed after performing a measurement, as it does not depend on pulse spacing; and the low signal to noise ratio allows multiple geographically separated transmitters to be used in the same frequency band without significantly interfering with each other. The latter allows the same receiver antennas to be used to receive multiple transmitters. 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. This would, for example, provide higher spatio-temporal resolution for mesospheric wind field measurements.

  12. Coded continuous wave meteor radar

    Science.gov (United States)

    Vierinen, J.; Chau, J. L.; Pfeffer, N.; Clahsen, M.; Stober, G.

    2015-07-01

    The concept of coded continuous wave meteor radar is introduced. The radar uses a continuously transmitted pseudo-random waveform, which has several advantages: coding avoids range aliased echoes, which are often seen with commonly used pulsed specular meteor radars (SMRs); continuous transmissions maximize pulse compression gain, allowing operation with significantly lower peak transmit power; the temporal resolution can be changed after performing a measurement, as it does not depend on pulse spacing; and the low signal to noise ratio allows multiple geographically separated transmitters to be used in the same frequency band without significantly interfering with each other. The latter allows the same receiver antennas to be used to receive multiple transmitters. 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. This would, for example, provide higher spatio-temporal resolution for mesospheric wind field measurements.

  13. High resolution observations of sporadic-E layers within the polar cap ionosphere using a new incoherent scatter radar experiment

    Directory of Open Access Journals (Sweden)

    B. Damtie

    Full Text Available High resolution observations of sporadic-E layers using a new experiment with the EISCAT (European Incoherent SCATter Svalbard radar (ESR are presented. The observations were made by means of a new type of hardware, which was connected in parallel with the standard receiver. The radar beam was aligned with the geomagnetic field. The experiment applies a new modulation principle. Two phase codes, one with 22 bits and the other with 5 bits, were transmitted at separate frequencies. Each bit was further modulated by a 5-bit Barker code. The basic bit length of both transmissions was 6 µs. Instead of storing the lagged products of the ionospheric echoes in the traditional way, samples of both the transmitted pulses and the ionospheric echoes were taken at intervals of 1 µs and stored on hard disk. The lagged products were calculated later in an off-line analysis. In the analysis a sidelobe-free Barker decoding technique was used. The experiment produces range ambiguities, which were removed by mathematical inversion. Sporadic-E layers were observed at 105–115 km altitudes, and they are displayed with a 150-m range resolution and a 10-s time resolution. The layers show sometimes complex shapes, including triple peaked structures. The thickness of these sublayers is of the order of 1–2 km and they may be separated by 5 km in range. While drifting downwards, the sublayers merge together to form a single layer. The plasma inside a layer is found to have a longer correlation length than that of the surrounding plasma. This may be an indication of heavy ions inside the layer. The field-aligned ion velocity is also calculated. It reveals shears in the meridional wind, which suggests that shears probably also exist in the zonal wind. Hence the wind shear mechanism is a possible generation mechanism of the layer. However, observations from the coherent SuperDARN radar indicate the presence of an ionospheric electric field pointing in the sector between

  14. Improving Weather Radar Precipitation Estimates by Combining two Types of Radars

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ellerbæk; Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2014-01-01

    the two radar types achieves a radar product with both long range and high temporal resolution. It is validated that the blended radar product performs better than the individual radars based on ground observations from laser disdrometers. However, the data combination is challenged by lower performance...

  15. MST radar data-base management

    Science.gov (United States)

    Wickwar, V. B.

    1983-01-01

    Data management for Mesospheric-Stratospheric-Tropospheric, (MST) radars is addressed. An incoherent-scatter radar data base is discussed in terms of purpose, centralization, scope, and nature of the data base management system.

  16. NOAA NEXt-Generation RADar (NEXRAD) Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of Level III weather radar products collected from Next-Generation Radar (NEXRAD) stations located in the contiguous United States, Alaska,...

  17. Design of multi-frequency CW radars

    CERN Document Server

    Jankiraman, Mohinder

    2007-01-01

    This book deals with the basic theory for design and analysis of Low Probability of Intercept (LPI) radar systems. The design of one such multi-frequency high resolution LPI radar, PANDORA, is covered.

  18. SMAP RADAR Processing and Calibration

    Science.gov (United States)

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

    2013-12-01

    The Soil Moisture Active Passive (SMAP) mission uses L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Model sensitivities translate the soil moisture accuracy to a radar backscatter accuracy of 1 dB at 3 km resolution and a brightness temperature accuracy of 1.3 K at 40 km resolution. This presentation will describe the level 1 radar processing and calibration challenges and the choices made so far for the algorithms and software implementation. To obtain the desired high spatial resolution the level 1 radar ground processor employs synthetic aperture radar (SAR) imaging techniques. Part of the challenge of the SMAP data processing comes from doing SAR imaging on a conically scanned system with rapidly varying squint angles. The radar echo energy will be divided into range/Doppler bins using time domain processing algorithms that can easily follow the varying squint angle. For SMAP, projected range resolution is about 250 meters, while azimuth resolution varies from 400 meters to 1.2 km. Radiometric calibration of the SMAP radar means measuring, characterizing, and where necessary correcting the gain and noise contributions from every part of the system from the antenna radiation pattern all the way to the ground processing algorithms. The SMAP antenna pattern will be computed using an accurate antenna model, and then validated post-launch using homogeneous external targets such as the Amazon rain forest to look for uncorrected gain variation. Noise subtraction is applied after image processing using measurements from a noise only channel. Variations of the internal electronics are tracked by a loopback measurement which will capture most of the time and temperature variations of the transmit power and receiver gain. Long-term variations of system performance due to component aging will be tracked and corrected using stable external reference

  19. Radar Observation of Insects - Mosquitoes

    Science.gov (United States)

    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.

  20. Scanning ARM Cloud Radar Handbook

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Radar research at The Pennsylvania State University Radar and Communications Laboratory

    Science.gov (United States)

    Narayanan, Ram M.

    2017-05-01

    The Radar and Communications Laboratory (RCL) at The Pennsylvania State University is at the forefront of radar technology and is engaged in cutting edge research in all aspects of radar, including modeling and simulation studies of novel radar paradigms, design and development of new types of radar architectures, and extensive field measurements in realistic scenarios. This paper summarizes the research at The Pennsylvania State University's Radar and Communications Laboratory and relevant collaborative research with several groups over the past 15 years in the field of radar and related technologies, including communications, radio frequency identification (RFID), and spectrum sensing.

  2. Radar operation in a hostile electromagnetic environment

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. An MSK Waveform for Radar Applications

    Science.gov (United States)

    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.

  4. Wind Turbine Radar Cross Section

    Directory of Open Access Journals (Sweden)

    David Jenn

    2012-01-01

    Full Text Available The radar cross section (RCS of a wind turbine is a figure of merit for assessing its effect on the performance of electronic systems. In this paper, the fundamental equations for estimating the wind turbine clutter signal in radar and communication systems are presented. Methods of RCS prediction are summarized, citing their advantages and disadvantages. Bistatic and monostatic RCS patterns for two wind turbine configurations, a horizontal axis three-blade design and a vertical axis helical design, are shown. The unique electromagnetic scattering features, the effect of materials, and methods of mitigating wind turbine clutter are also discussed.

  5. Compressive sensing for urban radar

    CERN Document Server

    Amin, Moeness

    2014-01-01

    With the emergence of compressive sensing and sparse signal reconstruction, approaches to urban radar have shifted toward relaxed constraints on signal sampling schemes in time and space, and to effectively address logistic difficulties in data acquisition. Traditionally, these challenges have hindered high resolution imaging by restricting both bandwidth and aperture, and by imposing uniformity and bounds on sampling rates.Compressive Sensing for Urban Radar is the first book to focus on a hybrid of two key areas: compressive sensing and urban sensing. It explains how reliable imaging, tracki

  6. Comparison of mimo radar concepts: Detection performance

    NARCIS (Netherlands)

    Rossum, W.L. van; Huizing, A.G.

    2007-01-01

    In this paper, four different array radar concepts are compared: pencil beam, floodlight, monostatic MIMO, and multistatic MIMO. The array radar concepts show an increase in complexity accompanied by an increase in diversity. The comparison between the radar concepts is made by investigating the

  7. Comparison of mimo radar concepts: Detection performance

    NARCIS (Netherlands)

    Rossum, W.L. van; Huizing, A.G.

    2007-01-01

    In this paper, four different array radar concepts are compared: pencil beam, floodlight, monostatic MIMO, and multistatic MIMO. The array radar concepts show an increase in complexity accompanied by an increase in diversity. The comparison between the radar concepts is made by investigating the det

  8. 46 CFR 15.815 - Radar observers.

    Science.gov (United States)

    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... endorsement as radar observer. (b) Each person who is employed or serves as pilot in accordance with...

  9. 46 CFR 11.480 - Radar observer.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 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...

  10. 46 CFR 130.310 - Radar.

    Science.gov (United States)

    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. ...

  11. 46 CFR 108.717 - Radar.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Radar. 108.717 Section 108.717 Shipping COAST GUARD... Miscellaneous Equipment § 108.717 Radar. Each self-propelled unit of 1,600 gross tons and over in ocean or coastwise service must have— (a) A marine radar system for surface navigation; and (b) Facilities on the...

  12. 46 CFR 167.40-40 - Radar.

    Science.gov (United States)

    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 plotting...

  13. Efficient Ways to Learn Weather Radar Polarimetry

    Science.gov (United States)

    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…

  14. Principles of modern radar advanced techniques

    CERN Document Server

    Melvin, William

    2012-01-01

    Principles of Modern Radar: Advanced Techniques is a professional reference for practicing engineers that provides a stepping stone to advanced practice with in-depth discussions of the most commonly used advanced techniques for radar design. It will also serve advanced radar academic and training courses with a complete set of problems for students as well as solutions for instructors.

  15. Comparison of mimo radar concepts: Detection performance

    NARCIS (Netherlands)

    Rossum, W.L. van; Huizing, A.G.

    2007-01-01

    In this paper, four different array radar concepts are compared: pencil beam, floodlight, monostatic MIMO, and multistatic MIMO. The array radar concepts show an increase in complexity accompanied by an increase in diversity. The comparison between the radar concepts is made by investigating the det

  16. FMCW Radar with Broadband Communication Capability

    NARCIS (Netherlands)

    Barrenechea, P.; Elferink, F.H.; Janssen, J.A.A.J.

    2007-01-01

    The use of amplitude modulation to encode information onto an FMCW radar signal is proposed in this paper. This new technique, that has been named AM-FMCW communicating radar, provides a new channel for broadband communication by reusing the radar frequencies and without introducing any distortion i

  17. Efficient Ways to Learn Weather Radar Polarimetry

    Science.gov (United States)

    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…

  18. Synthetic aperture radar capabilities in development

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The Imaging and Detection Program (IDP) within the Laser Program is currently developing an X-band Synthetic Aperture Radar (SAR) to support the Joint US/UK Radar Ocean Imaging Program. The radar system will be mounted in the program`s Airborne Experimental Test-Bed (AETB), where the initial mission is to image ocean surfaces and better understand the physics of low grazing angle backscatter. The Synthetic Aperture Radar presentation will discuss its overall functionality and a brief discussion on the AETB`s capabilities. Vital subsystems including radar, computer, navigation, antenna stabilization, and SAR focusing algorithms will be examined in more detail.

  19. Mars Radar Opens a Planet's Third Dimension

    Science.gov (United States)

    2008-01-01

    Radar sounder instruments orbiting Mars have looked beneath the Martian surface and opened up the third dimension for planetary exploration. The technique's success is prompting scientists to think of all the other places in the Solar System where they would like to use radar sounders. The first radar sounder at Mars was the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) on the European Space Agency's Mars Express Orbiter. It has been joined by the complementary Shallow Subsurface Radar (SHARAD), operating at a different wavelength aboard NASA's Mars Reconnaissance Orbiter. The data in this animation are from SHARAD.

  20. Radar for Mapping Sea Ice

    Science.gov (United States)

    Barath, F. T.; Jordan, R. L.

    1983-01-01

    X-band system has 100-m2 resolution. Wide swath imaging radar of synthetic aperature type transmits signal to ground station for subsequent processing into imagery. Concept meets functional requirements for continuously mapping sea ice in north and south polar regions.

  1. Measurements of radar ground returns

    NARCIS (Netherlands)

    Loor, G.P. de

    1974-01-01

    The ground based measurement techniques for the determination of the radar back-scatter of vegetation and soils as used in The Netherlands will be described. Two techniques are employed: one covering a large sample area (> 1000 m2) but working at low grazing angels only and one (short range) coverin

  2. Wind Retrieval using Marine Radars

    Science.gov (United States)

    2011-09-30

    Interaction (HiRes) DRI the NATO Undersea Research Center ( NURC ) wants to develop and validate methodologies to retrieve wind field parameters from X-band...marine radar. The main parameters NURC will focus on are the mean surface wind vector as well as the wind gusts in vicinity of the measurement platform

  3. High-Resolution Instrumentation Radar.

    Science.gov (United States)

    1986-09-30

    30 September 1986 Los Angeles Air Force Station 13. NUMBER OF PAGES Los Angeles, Calif. 90009-2960 36 74. MONITORING AGENCY NAME & ADDRESS(If...TREE PLMUT ",-20 -CUTLIASS DumpER SED AN... TREE TRUNK, -0 - MERC BUMPER f - 40 H!-I -50 iI Fig. 7. High-Resolution Instrumentation Radar View of

  4. Planetary Radars Operating Centre PROC

    Science.gov (United States)

    Catallo, C.; Flamini, E.; Seu, R.; Alberti, G.

    2007-12-01

    Planetary exploration by means of radar systems, mainly using Ground Penetrating Radars (GPR) plays an important role in Italy. Numerous scientific international space programs are currently carried out jointly with ESA and NASA by Italian Space Agency, the scientific community and the industry. Three important experiments under Italian leadership ( designed and manufactured by the Italian industry), provided by ASI either as contribution to ESA programs either within a NASA/ASI joint venture framework, are now operating: MARSIS on-board Mars Express, SHARAD on-board Mars Reconnaissance Orbiter and CASSINI Radar on-board Cassini spacecraft. In order to support all the scientific communities, institutional customers and experiment teams operation three Italian dedicated operational centers have been realized, namely SHOC, (Sharad Operating Centre), MOC (Marsis Operating Center) and CASSINI PAD ( Processing Altimetry Data). Each center is dedicated to a single instrument management and control, data processing and distribution. Although they had been conceived to operate autonomously and independently one from each other, synergies and overlaps have been envisaged leading to the suggestion of a unified center, the Planetary Radar Processing Center (PROC). PROC is conceived in order to include the three operational centers, namely SHOC, MOC and CASSINI PAD, either from logistics point of view and from HW/SW capabilities point of view. The Planetary Radar Processing Center shall be conceived as the Italian support facility to the scientific community for on-going and future Italian planetary exploration programs. Therefore, scalability, easy use and management shall be the design drivers. The paper describes how PROC is designed and developed, to allow SHOC, MOC and CASSINI PAD to operate as before, and to offer improved functionalities to increase capabilities, mainly in terms of data exchange, comparison, interpretation and exploitation. Furthermore, in the frame of

  5. Monitoring by holographic radar systems

    Science.gov (United States)

    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

  6. Status and Prospects of Radar Polarimetry Techniques

    Directory of Open Access Journals (Sweden)

    Wang Xuesong

    2016-04-01

    Full Text Available Radar polarimetry is an applied fundamental science field that is focused on understanding interaction processes between radar waves and targets and disclosing their mechanisms. Radar polarimetry has significant application prospects in the fields of microwave remote sensing, earth observation, meteorological measurement, battlefield reconnaissance, anti-interference, target recognition, and so on. This study briefly reviews the development history of radar polarization theory and technology. Next, the state of the art of several key technologies within radar polarimetry, including the precise acquisition of radar polarization information, polarization-sensitive array signal processing, target polarization characteristics, polarization antiinterference, and target polarization classification and recognition, is summarized. Finally, the future developments of radar polarization technology are considered.

  7. All-optical bandwidth-tailorable radar

    CERN Document Server

    Zou, Weiwen; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2015-01-01

    Radar has been widely used in military, security, and rescue. Metamaterial cloak is employed in stealth targets to evade radar detection. Hence modern radar should be reconfigurable at multi-bands for detecting stealth targets, which might be realized based on microwave photonics. Here, we demonstrate an all-optical bandwidth-tailorable radar architecture. It is a coherent system utilizing one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates wideband linearly-chirped radar signal. The working bands can be flexibly tailored with desired bandwidth at user-preferred carrier frequency. After modulated onto the pre-chirped optical pulse, radar echoes are time-stretched and frequency-compressed by several times. The digitization becomes much easier without loss of detection ability. We believe that the demonstration can innovate the radar's architecture with ultra-high range resolution.

  8. Radar research at the University of Kansas

    Science.gov (United States)

    Blunt, Shannon D.; Allen, Christopher; Arnold, Emily; Hale, Richard; Hui, Rongqing; Keshmiri, Shahriar; Leuschen, Carlton; Li, Jilu; Paden, John; Rodriguez-Morales, Fernando; Salandrino, Alessandro; Stiles, James

    2017-05-01

    Radar research has been synonymous with the University of Kansas (KU) for over half a century. As part of this special session organized to highlight significant radar programs in academia, this paper surveys recent and ongoing work at KU. This work encompasses a wide breadth of sensing applications including the remote sensing of ice sheets, autonomous navigation methods for unmanned aerial vehicles (UAVs), novel laser radar capabilities, detection of highenergy cosmic rays using bistatic radar, different forms of waveform diversity such as MIMO radar and pulse agility, and various radar-embedded communication methods. The results of these efforts impact our understanding of the changing nature of the environment, address the proliferation of unmanned systems in the US airspace, realize new sensing modalities enabled by the joint consideration of electromagnetics and signal processing, and greater facilitate radar operation in an increasingly congested and contested spectrum.

  9. Basic Radar Altimetry Toolbox & Tutorial

    Science.gov (United States)

    Rosmorduc, Vinca; Benveniste, Jerome; Breebaart, Leo; Bronner, Emilie; Dinardo, Salvatore; Earith, Didier; Lucas, Bruno Manuel; Niejmeier, Sander; Picot, Nicolas

    2010-12-01

    The Basic Radar Altimetry Toolbox is an "all-altimeter" collection of tools, tutorials and documents designed to facilitate the use of radar altimetry data, including the last mission launched, CryoSat. It has been available from April 2007, and had been demonstrated during training courses and scientific meetings. Nearly 1200 people downloaded it (as of end of June 2010), with many "newcomers" to altimetry among them. Users' feedbacks, developments in altimetry, and practice, showed that new interesting features could be added. Some have been added and/or improved in version 2. Others are ongoing, some are in discussion. The Basic Radar Altimetry Toolbox is able: - to read most distributed radar altimetry data, from ERS-1 & 2, Topex/Poseidon, Geosat Follow-on, Jason- 1, Envisat, Jason- 2, CryoSat and also the future Saral and Sentinel 3 missions, - to perform some processing, data editing and statistic, - and to visualize the results. It can be used at several levels/several ways: - as a data reading tool, with APIs for C, Fortran, Matlab and IDL - as processing/extraction routines, through the on-line command mode - as an educational and a quick-look tool both, with the graphical user interface As part of the Toolbox, a Radar Altimetry Tutorial gives general information about altimetry, the technique involved and its applications, as well as an overview of past, present and future missions, including information on how to access data, additional software and documentation. It also presents a series of data use cases, covering all uses of altimetry over ocean, cryosphere and land, showing the basic methods for some of the most frequent manners of using altimetry data. BRAT is developed under contract with ESA and CNES. It is available at http://www.altimetry.info and http://earth.esa.int/brat/

  10. Molecular characterization and specific detection of Anaplasma species (AP-sd) in sika deer and its first detection in wild brown bears and rodents in Hokkaido, Japan.

    Science.gov (United States)

    Moustafa, Mohamed Abdallah Mohamed; Lee, Kyunglee; Taylor, Kyle; Nakao, Ryo; Sashika, Mariko; Shimozuru, Michito; Tsubota, Toshio

    2015-12-01

    A previously undescribed Anaplasma species (herein referred to as AP-sd) has been detected in sika deer, cattle and ticks in Japan. Despite being highly similar to some strains of A. phagocytophilum, AP-sd has never been detected in humans. Its ambiguous epidemiology and the lack of tools for its specific detection make it difficult to understand and interpret the prevalence of this Anaplasma species. We developed a method for specific detection, and examined AP-sd prevalence in Hokkaido wildlife. Our study included 250 sika deer (Cervus nippon yesoensis), 13 brown bears (Ursus arctos yesoensis) and 252 rodents including 138 (Apodemus speciosus), 45 (Apodemus argenteus), 42 (Myodes rufocanus) and 27 (Myodes rutilus) were collected from Hokkaido island, northern Japan, collected during 2010 to 2015. A 770 bp and 382 bp segment of the 16S rRNA and gltA genes, respectively, were amplified by nested PCR. Results were confirmed by cloning and sequencing of the positive PCR products. A reverse line blot hybridization (RLB) based on the 16S rRNA gene was then developed for the specific detection of AP-sd. The prevalence of AP-sd by nested PCR in sika deer was 51% (128/250). We detected this Anaplasma sp. for the first time in wild brown bears and rodents with a prevalence of 15% (2/13) and 2.4% (6/252), respectively. The sequencing results of the 16S rRNA and gltA gene amplicons were divergent from the selected A. phagocytophilum sequences in GenBank. Using a newly designed AP-sd specific probe for RLB has enabled us to specifically detect this Anaplasma species. Besides sika deer and cattle, wild brown bears and rodents were identified as potential reservoir hosts for AP-sd. This study provided a high throughput molecular method that specifically detects AP-sd, and which can be used to investigate its ecology and its potential as a threat to humans in Japan.

  11. Alpine radar conversion for LAWR

    Science.gov (United States)

    Savina, M.; Burlando, P.

    2012-04-01

    The Local Area Weather Radar (LAWR) is a ship-born weather radar system operating in X-band developed by the DHI Group to detect precipitation in urban areas. To date more than thirty units are installed in different settings around the world. A LAWR was also deployed in the Alps, at 3883 m a.s.l. on the Kl. Matterhorn (Valais, Switzerland). This was the highest LAWR of the world and it led to the development of an Alpine LAWR system that, besides featuring important technological improvements needed to withstand the severe Alpine conditions, required the development of a new Alpine Radar COnversion Model (ARCOM), which is the main focus of this contribution. The LAWR system is equipped with the original FURUNO fan-beam slotted antenna and the original logarithmic receiver, which limits the radar observations to the video signal (L) withour providing the reflectivity (Z). The beam is 0.95 deg wide and 20 deg high. It can detect precipitation to a max range of 60 km. In order to account for the limited availability of raw signal and information and the specific mountain set-up, the conversion model had to be developed differently from the state-of-the-art radar conversion technique used for this class of radars. In particular, the ARCOM is based on a model used to simulate a spatial dependent factor, hereafter called ACF, which is in turn function of parameters that take in account climatological conditions, also used in other conversion methods, but additionally accounting for local radar beam features and for orographic forcings such as the effective sampling power (sP), which is modelled by means of antenna pattern, geometric ground clutter and their interaction. The result is a conversion factor formulated to account for a range correction that is based on the increase of the sampling volume, partial beam blocking and local climatological conditions. The importance of the latter in this study is double with respect to the standard conversion technique for this

  12. Advances in Ice Penetrating Radar

    Science.gov (United States)

    Paden, J. D.

    2016-12-01

    Radars have been employed for ice remote sensing since the mid-twentieth century. The original application in radioglaciology was to obtain ice thickness: an essential parameter in ice flux calculations and boundary condition in ice flow models. Later, radars were used to estimate basal conditions and track laterally persistent features in the ice. The Center for Remote Sensing of Ice Sheet's recent hardware advances include multichannel systems and radar suites covering the usable frequency spectrum. These advances coupled with increased interest in the polar regions result in a concomitant exponential growth in data. We focus on a few results that have come from these changes. Multichannel radar systems improved clutter rejection and enabled 3D imaging. Using computer vision algorithms, we have automated the process of extracting the ice bottom surface in 3D imagery for complex topographies including narrow glacier channels where the ice surface and ice bottom merge together within the 3D images. We present results of wide swath imaging which have enabled narrow, 2-3 km wide, glacier channels to be fully imaged in a single pass. When radar data are available across the frequency spectrum, we have the ability to enhance target detection and measure frequency dependent properties. For example, we can couple HF sounder measurements in warmer ice where scattering attenuates and hides the signal of interest with VHF sounder measurements in cooler ice which have much improved resolution from a single flight line. We present examples of improved bed detection with coupled HF and VHF imagery in a temperate to cold ice transition that show the strong frequency dependence of englacial scattering. To handle the increased data rate, we developed a standard processing chain and data product for CReSIS radar systems, including legacy systems. Application specific GIS tools are an essential part and enable us to merge other data products during data analysis. By using imagery

  13. Specific molecular detection of Anaplasma sp. closely related to Anaplasma phagocytophilum in ixodid ticks and cattle in a pastureland in Hokkaido, Japan.

    Science.gov (United States)

    Ybañez, Adrian P; Tagawa, Michihito; Matsumoto, Kotaro; Kishimoto, Toshio; Yokoyama, Naoaki; Inokuma, Hisashi

    2013-01-01

    Recent molecular analyses of the Anaplasma sp. closely related to Anaplasma phagocytophilum (previously believed to be A. phagocytophilum) in Japan have clarified its distinct phylogenetic position. PCR methods relying on 16S rRNA- and P44/MSP2-based primers designed to detect this species have low sensitivity and specificity. In this study, a highly sensitive and specific nested PCR method using newly designed primers based on heat-shock operon gene (groEL) was developed to detect this species. The method was later used in an epidemiological study testing DNA samples from 85 Ixodid ticks (collected by flagging) and 50 cattle from the same pastureland in Nakaosobetsu, Hokkaido, Japan. Results revealed prevalence rates of 2.4% (2 of 85) in ticks and 2% (1 of 50) in cattle. The present study also reported the first molecular detection of the Anaplasma sp. closely related to A. phagocytophilum in Japan in H. douglasii, and established a new reliable PCR method that detects this Anaplasma sp. closely related to A. phagocytophilum in Japan.

  14. Genetic and antigenic characterization of H5 and H7 influenza viruses isolated from migratory water birds in Hokkaido, Japan and Mongolia from 2010 to 2014.

    Science.gov (United States)

    Hiono, Takahiro; Ohkawara, Ayako; Ogasawara, Kohei; Okamatsu, Masatoshi; Tamura, Tomokazu; Chu, Duc-Huy; Suzuki, Mizuho; Kuribayashi, Saya; Shichinohe, Shintaro; Takada, Ayato; Ogawa, Hirohito; Yoshida, Reiko; Miyamoto, Hiroko; Nao, Naganori; Furuyama, Wakako; Maruyama, Junki; Eguchi, Nao; Ulziibat, Gerelmaa; Enkhbold, Bazarragchaa; Shatar, Munkhduuren; Jargalsaikhan, Tserenjav; Byambadorj, Selenge; Damdinjav, Batchuluun; Sakoda, Yoshihiro; Kida, Hiroshi

    2015-08-01

    Migratory water birds are the natural reservoir of influenza A viruses. H5 and H7 influenza viruses are isolated over the world and also circulate among poultry in Asia. In 2010, two H5N1 highly pathogenic avian influenza viruses (HPAIVs) were isolated from fecal samples of water birds on the flyway of migration from Siberia, Russia to the south in Hokkaido, Japan. H7N9 viruses are sporadically isolated from humans and circulate in poultry in China. To monitor whether these viruses have spread in the wild bird population, we conducted virological surveillance of avian influenza in migratory water birds in autumn from 2010 to 2014. A total of 8103 fecal samples from migratory water birds were collected in Japan and Mongolia, and 350 influenza viruses including 13 H5 and 19 H7 influenza viruses were isolated. A phylogenetic analysis revealed that all isolates are genetically closely related to viruses circulating among wild water birds. The results of the antigenic analysis indicated that the antigenicity of viruses in wild water birds is highly stable despite their nucleotide sequence diversity but is distinct from that of HPAIVs recently isolated in Asia. The present results suggest that HPAIVs and Chinese H7N9 viruses were not predominantly circulating in migratory water birds; however, continued monitoring of H5 and H7 influenza viruses both in domestic and wild birds is recommended for the control of avian influenza.

  15. Short-Term Response of Sasa Dwarf Bamboo to a Change of Soil Nitrogen Fertility in a Forest Ecosystem in Northern Hokkaido, Japan.

    Science.gov (United States)

    Watanabe, Tsunehiro; Fukuzawa, Karibu; Shibata, Hideaki

    2016-04-14

    In forest ecosystems, a change of soil nitrogen (N) cycling after disturbance is regulated by various factors. Sasa dwarf bamboo (hereafter referred to as Sasa) is an understory plant that grows thickly on the forest floor in northern Hokkaido, Japan. However, the ecosystem function of Sasa after disturbances in the soil N cycling is not fully understood. The purpose of this study was to determine the short-term response of Sasa to a change of soil N fertility. Biomass, litterfall, litter decomposition, soil N pool, and N leaching from soil were measured in control, and low- (5 g N m(-2) year(-1)) and high-N (15 g N m(-2) year(-1)) addition plots. Sasa immobilized much N as the soil N fertility increased. However, the leaf N concentration in aboveground biomass did not increase, suggesting that the N in leaves was maintained because of the increase of leaf biomass. As a result, the decomposition and mineralization rates of the produced litter before and after N addition were comparable among plots, even though the soil inorganic N fertility increased greatly. These results suggest that immediate response of Sasa to an increase of soil inorganic N mitigates the excess N leaching from soil.

  16. Muon radiography and deformation analysis of the lava dome formed by the 1944 eruption of Usu, Hokkaido--contact between high-energy physics and volcano physics--.

    Science.gov (United States)

    K M Tanaka, Hiroyuki; Yokoyama, Izumi

    2008-01-01

    Lava domes are one of the conspicuous topographic features on volcanoes. The subsurface structure of the lava dome is important to discuss its formation mechanism. In the 1944 eruption of Volcano Usu, Hokkaido, a new lava dome was formed at its eastern foot. After the completion of the lava dome, various geophysical methods were applied to the dome to study its subsurface structure, but resulted in a rather ambiguous conclusion. Recently, from the results of the levelings, which were repeated during the eruption, "pseudo growth curves" of the lava dome were obtained. The curves suggest that the lava dome has a bulbous shape. In the present work, muon radiography, which previously proved effective in imaging the internal structure of Volcano Asama, has been applied to the Usu lava dome. The muon radiography measures the distribution of the "density length" of volcanic bodies when detectors are arranged properly. The result obtained is consistent with the model deduced from the pseudo growth curves. The measurement appears to afford useful method to clarify the subsurface structure of volcanoes and its temporal changes, and in its turn to discuss volcanic processes. This is a point of contact between high-energy physics and volcano physics.

  17. Genomic characterization of echovirus 6 causing aseptic meningitis in Hokkaido, Japan: a novel cluster in the nonstructural protein coding region of human enterovirus B.

    Science.gov (United States)

    Miyoshi, Masahiro; Komagome, Rika; Ishida, Setsuko; Nagano, Hideki; Takahashi, Kenichi; Okano, Motohiko

    2013-04-01

    We determined four complete nucleotide sequences of echovirus 6 (E6) isolated from an epidemic of aseptic meningitis (AM) in Hokkaido, Japan, in 2011. Phylogenetic analysis of the genes encoding viral capsid protein 1 revealed that the strains were closely related to E6 strains isolated in China in recent years, but they were distantly related to E6 strains isolated from patients with AM in Osaka Prefecture, Japan, in 2011. The genes encoding the viral protease and RNA-dependent RNA polymerase (3CD) were closely related to those of several non-E6 strains of the species Human enterovirus B isolated in China, South Korea, and Australia from 1999 to 2010, resulting in a novel cluster in the phylogenetic tree. These results suggest that the incidence of AM in Japan in 2011 was caused by at least two lineages of E6 strains, and a lineage of the 3CD gene was interspersed among different serotypic strains isolated in Western Pacific countries.

  18. Muon radiography and deformation analysis of the lava dome formed by the 1944 eruption of Usu, Hokkaido —Contact between high-energy physics and volcano physics—

    Science.gov (United States)

    TANAKA, Hiroyuki K. M.; YOKOYAMA, Izumi

    2008-01-01

    Lava domes are one of the conspicuous topographic features on volcanoes. The subsurface structure of the lava dome is important to discuss its formation mechanism. In the 1944 eruption of Volcano Usu, Hokkaido, a new lava dome was formed at its eastern foot. After the completion of the lava dome, various geophysical methods were applied to the dome to study its subsurface structure, but resulted in a rather ambiguous conclusion. Recently, from the results of the levelings, which were repeated during the eruption, “pseudo growth curves” of the lava dome were obtained. The curves suggest that the lava dome has a bulbous shape. In the present work, muon radiography, which previously proved effective in imaging the internal structure of Volcano Asama, has been applied to the Usu lava dome. The muon radiography measures the distribution of the “density length” of volcanic bodies when detectors are arranged properly. The result obtained is consistent with the model deduced from the pseudo growth curves. The measurement appears to afford useful method to clarify the subsurface structure of volcanoes and its temporal changes, and in its turn to discuss volcanic processes. This is a point of contact between high-energy physics and volcano physics. PMID:18941290

  19. Magnetotelluric investigation in and around southern part of Hidaka metamorphic belt in Hokkaido, Japan; Hidaka henseitai nanbuiki ni okeru MT kansoku

    Energy Technology Data Exchange (ETDEWEB)

    Sato, H.; Utsugi, M.; Hirano, K.; Doi, T.; Nishida, Y.; Arita, K. [Hokkaido University, Sapporo (Japan)

    1996-05-01

    An MT observation was conducted in the Hidaka district, Hokkaido, for the estimation of the 2D resistivity structure in the southern part of the metamorphic belt, when frequencies of the VLF, ELF, and ULF bands were used. An approximately 42km-long traverse line was set to cross the Hidaka metamorphic belt from east to west. As for the observation points, 48 VLF points, 16 ELF points, and 4 ULF points were provided. During the data processing, impedance tensor was calculated in the frequency domain for the determination of the apparent resistivity relative to frequency and the phase difference. As the result, it was found that there is a fairly large resistivity gap between observation spots MNS and KWR and that the boundary corresponds to the Hidaka metamorphic belt, that the metamorphic belt that is reflected as a conspicuous high-resistivity layer in the VLF-, ELF-MT slopes down toward the east and has a distribution as deep as 10km in the vicinity of observation point KWR, that this high-resistivity layer sandwiches a low-resistivity layer at a depth of 5-7km, and that on the east side of the metamorphic belt there is a medium-resistivity layer creeping under the belt from the east side toward the west side. 5 refs., 6 figs.

  20. Penn State Radar Systems: Implementation and Observations

    Science.gov (United States)

    Urbina, J. V.; Seal, R.; Sorbello, R.; Kuyeng, K.; Dyrud, L. P.

    2014-12-01

    Software Defined Radio/Radar (SDR) platforms have become increasingly popular as researchers, hobbyists, and military seek more efficient and cost-effective means for radar construction and operation. SDR platforms, by definition, utilize a software-based interface for configuration in contrast to traditional, hard-wired platforms. In an effort to provide new and improved radar sensing capabilities, Penn State has been developing advanced instruments and technologies for future radars, with primary objectives of making such instruments more capable, portable, and more cost effective. This paper will describe the design and implementation of two low-cost radar systems and their deployment in ionospheric research at both low and mid-latitudes. One radar has been installed near Penn State campus, University Park, Pennsylvania (77.97°W, 40.70°N), to make continuous meteor observations and mid-latitude plasma irregularities. The second radar is being installed in Huancayo (12.05°S, -75.33°E), Peru, which is capable of detecting E and F region plasma irregularities as well as meteor reflections. In this paper, we examine and compare the diurnal and seasonal variability of specular, non- specular, and head-echoes collected with these two new radar systems and discuss sampling biases of each meteor observation technique. We report our current efforts to validate and calibrate these radar systems with other VHF radars such as Jicamarca and SOUSY. We also present the general characteristics of continuous measurements of E-region and F-region coherent echoes using these modern radar systems and compare them with coherent radar events observed at other geographic mid-latitude radar stations.

  1. Detecting and classifying low probability of intercept radar

    CERN Document Server

    Pace, Philip E

    2008-01-01

    This revised and expanded second edition brings you to the cutting edge with new chapters on LPI radar design, including over-the-horizon radar, random noise radar, and netted LPI radar. You also discover critical LPI detection techniques, parameter extraction signal processing techniques, and anti-radiation missile design strategies to counter LPI radar.

  2. MIMO Radar Using Compressive Sampling

    CERN Document Server

    Yu, Yao; Poor, H Vincent

    2009-01-01

    A MIMO radar system is proposed for obtaining angle and Doppler information on potential targets. Transmitters and receivers are nodes of a small scale wireless network and are assumed to be randomly scattered on a disk. The transmit nodes transmit uncorrelated waveforms. Each receive node applies compressive sampling to the received signal to obtain a small number of samples, which the node subsequently forwards to a fusion center. Assuming that the targets are sparsely located in the angle- Doppler space, based on the samples forwarded by the receive nodes the fusion center formulates an l1-optimization problem, the solution of which yields target angle and Doppler information. The proposed approach achieves the superior resolution of MIMO radar with far fewer samples than required by other approaches. This implies power savings during the communication phase between the receive nodes and the fusion center. Performance in the presence of a jammer is analyzed for the case of slowly moving targets. Issues rel...

  3. Array radars solve communication jams

    Science.gov (United States)

    Lewis, H. D.

    1982-04-01

    The possibilities of incorporating mobile radar units as slave stations in communications relay applications during times of disrupted communications is examined. The limitations on uses of search, tracking, and multifunction radars are examined, noting that employment of the mobile system entails some tracking by the master phased-arrays to keep the mobile units in focus. The tracking patterns and dwell times are outlined, and the possibility of 700-1000 dwell times of 1220 microsec duration/sec is mentioned as opening the opportunity for high quality data transmissions. Signal-to-noise ratios are formulated for jamming situations, with offsetting tactical features for the jamming including the directivity and gain of the master antenna, the master station's power aperture product, on-axis to off-axis gain ratio, and antenna positioning ability. A slave station must be equipped with a transponder for communications, which are best achieved with pseudo-random coded waveforms.

  4. Reliability of Naval Radar Systems

    Science.gov (United States)

    1978-09-01

    CONFIDENTIAL (THIS PACE IS UNCUIASSFIED) CONFIDENTIAL (U) For airborne radars, 3-M’(Maintenance and Material Management )and RISE (Readiness Improvement...of the 3-M Program reports (3-M from Maintenance and Material Management ) as well as Naval Air Systems Command RISE (Readi-. ness Improvement Summary...TRANSIT PULSE LE11CTR (;As): 12.8 ANTENNA UEIGHr (k 1058 (2331 lbs.) excluding pedestal COMPRESSED PLUE LENGTH (.is): 0.2 BEAN POSITIObiNG TECNIQUES : H)RZ

  5. Radar Control Optimal Resource Allocation

    Science.gov (United States)

    2015-07-13

    Campaign as shown in Figure 7. This radar is an experimental frequency agile, high-resolution originally developed for the purpose of iceberg detection...Information Theory , Under Review 2015. [24] A. Pezeshki, A. Calderbank, W. Moran, and S. Howard, “Doppler resilient golay complemn- tary waveforms...IEEE Transactions on Information Theory , vol. 54, no. 9, pp. 4254–4266, 2008. [25] W. Dang, A. Pezeshki, S. Howard, B. Moran, and R. Calderbank

  6. Radar based autonomous sensor module

    Science.gov (United States)

    Styles, Tim

    2016-10-01

    Most surveillance systems combine camera sensors with other detection sensors that trigger an alert to a human operator when an object is detected. The detection sensors typically require careful installation and configuration for each application and there is a significant burden on the operator to react to each alert by viewing camera video feeds. A demonstration system known as Sensing for Asset Protection with Integrated Electronic Networked Technology (SAPIENT) has been developed to address these issues using Autonomous Sensor Modules (ASM) and a central High Level Decision Making Module (HLDMM) that can fuse the detections from multiple sensors. This paper describes the 24 GHz radar based ASM, which provides an all-weather, low power and license exempt solution to the problem of wide area surveillance. The radar module autonomously configures itself in response to tasks provided by the HLDMM, steering the transmit beam and setting range resolution and power levels for optimum performance. The results show the detection and classification performance for pedestrians and vehicles in an area of interest, which can be modified by the HLDMM without physical adjustment. The module uses range-Doppler processing for reliable detection of moving objects and combines Radar Cross Section and micro-Doppler characteristics for object classification. Objects are classified as pedestrian or vehicle, with vehicle sub classes based on size. Detections are reported only if the object is detected in a task coverage area and it is classified as an object of interest. The system was shown in a perimeter protection scenario using multiple radar ASMs, laser scanners, thermal cameras and visible band cameras. This combination of sensors enabled the HLDMM to generate reliable alerts with improved discrimination of objects and behaviours of interest.

  7. Radar channel balancing with commutation

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  8. Automotive Radar Sensors in Silicon Technologies

    CERN Document Server

    Jain, Vipul

    2013-01-01

    This book presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors.  This book bridges an existing gap between information available on dependable system/architecture design and circuit design.  It provides the background of the field and detailed description of recent research and development of silicon-based radar sensors.  System-level requirements and circuit topologies for radar transceivers are described in detail. Holistic approaches towards designing radar sensors are validated with several examples of highly-integrated radar ICs in silicon technologies. Circuit techniques to design millimeter-wave circuits in silicon technologies are discussed in depth.  Describes concepts and fundamentals of automotive rada...

  9. Signal Processing for Radar with Array Antennas and for Radar with Micro-Doppler Measurements

    OpenAIRE

    Björklund, Svante

    2017-01-01

    Radar (RAdio Detection And Ranging) uses radio waves to detect the presence of a target and measure its position and other properties. This sensor has found many civilian and military applications due to advantages such as possible large surveillance areas and operation day and night and in all weather. The contributions of this thesis are within applied signal processing for radar in two somewhat separate research areas: 1) radar with array antennas and 2) radar with micro-Doppler measuremen...

  10. Bistatic Forward Scattering Radar Detection and Imaging

    OpenAIRE

    2016-01-01

    Forward Scattering Radar (FSR) is a special type of bistatic radar that can implement image detection, imaging, and identification using the forward scattering signals provided by the moving targets that cross the baseline between the transmitter and receiver. Because the forward scattering effect has a vital significance in increasing the targets’ Radar Cross Section (RCS), FSR is quite advantageous for use in counter stealth detection. This paper first introduces the front line technology u...

  11. Artifacts in Radar Imaging of Moving Targets

    Science.gov (United States)

    2012-09-01

    leads to the wrong object localization and defocusing on the image. For SAR , a moving target’s physical location varies throughout the imaging...Imaging, Synthetic Aperture Radar, Bistatic Radar, Multistatic Radar, Moving Targets, Backprojection 15. NUMBER OF PAGES 133 16. PRICE CODE 17...broadening and range errors were introduced by target motion. This leads to incorrect object localization and defocusing on the image. For SAR , a

  12. Fully Adaptive Radar Modeling and Simulation Development

    Science.gov (United States)

    2017-04-01

    Organization (NATO) Sensors Electronics Technology (SET)-227 Panel on Cognitive Radar. The FAR M&S architecture developed in Phase I allows for...Air Force’s previously developed radar M&S tools. This report is organized as follows. In Chapter 3, we provide an overview of the FAR framework...AFRL-RY-WP-TR-2017-0074 FULLY ADAPTIVE RADAR MODELING AND SIMULATION DEVELOPMENT Kristine L. Bell and Anthony Kellems Metron, Inc

  13. Intra-Pulse Radar-Embedded Communications

    Science.gov (United States)

    2011-08-26

    Blunt, E. Mokole, R. Schneible, and M. Wicks, SciTech Publishing, 2010. 3. S.D. Blunt, T. Higgins, A.K. Shackelford , and K. Gerlach, “Multistatic... Shackelford , “Multi-dimensional Adaptive Processing for Angle-Dependent Radar Waveforms,” in preparation for IET Radar, Sonar & Navigation. 8. H... Shackelford , “Time-Range Adaptive Processing for Pulse Agile Radar,” 5 th International Waveform Diversity & Design Conference, Niagara Falls, Canada

  14. Preliminary results of noise radar experiments

    Science.gov (United States)

    Malanowski, Mateusz; Contartese, Clara; Maslikowski, Lukasz; Baczyk, Marcin; Kulpa, Krzysztof

    2009-06-01

    The paper describes the first results of noise radar experiments carried out at Warsaw University of Technology. The radar system was built with Commercial Off-The-Shelf (COTS) components: log-periodic antennas, an arbitrary waveform generator and a two-channel spectrum analyzer. The radar operated in the continuous-wave mode, and the aim was to detect moving targets in the received signal. The paper shows the system setup as well as the numerical results obtained from the recorded signals.

  15. Ground Penetrating Radar: Ultra-wideband radars for improvised explosive devices and landmine detection

    NARCIS (Netherlands)

    Yarovoy, A.

    2008-01-01

    For last two decades Ultra-Wideband Ground Penetrating Radars seemed to be a useful tool for detection and classification of landmines and improvised explosive devices (IEDs). However limitations of radar technology considerably limited operational use of these radars. Recent research at TU Delft so

  16. Ground Penetrating Radar: Ultra-wideband radars for improvised explosive devices and landmine detection

    OpenAIRE

    Yarovoy, A.

    2008-01-01

    For last two decades Ultra-Wideband Ground Penetrating Radars seemed to be a useful tool for detection and classification of landmines and improvised explosive devices (IEDs). However limitations of radar technology considerably limited operational use of these radars. Recent research at TU Delft solves the bottleneck problems.

  17. Radar hydrology principles, models, and applications

    CERN Document Server

    Hong, Yang

    2014-01-01

    ""This is the first book on radar hydrology written by hydrologists. Whereas the excellent knowledge of radar technology by the authors permits an adequate coverage of the principles of rainfall rate estimation by radar, their hydrological background allows them to provide a unique message on the benefits (and on the remaining challenges) in exploiting radar techniques in hydrology. … In a clear and concise manner, the book combines topics from different scientific disciplines into a unified approach aiming to guide the reader through the requirements, strengths, and pitfalls of the applica

  18. Search Radar ECM/EA Simulator

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Tests the effectiveness of electronic countermeasures/electronic attack (ECM/EA) equipment and techniques for jamming airborne search and targeting radars....

  19. Future of phased array radar systems

    Science.gov (United States)

    Bassyouni, Ahmed

    2011-12-01

    This paper spots the light on the future progress of phased array radar systems, presenting two innovative examples on the directions of development. The first example starts with the classic radar range equation to develop the topology of what is called a "Mobile Adaptive Digital Array Radar" (MADAR) system. The second example discusses the possibility to achieve what is called "Entangled Photonic Radar" (EPR) system. The EPR quantum range equation is derived and compared to the classic one to compare the performance. Block diagrams and analysis for both proposed systems are presented.

  20. Radar reflection off extensive air showers

    Directory of Open Access Journals (Sweden)

    Werner F.

    2013-06-01

    Full Text Available We investigate the possibility of detecting extensive air showers by the radar technique. Considering a bistatic radar system and different shower geometries, we simulate reflection of radio waves off the static plasma produced by the shower in the air. Using the Thomson cross-section for radio wave reflection, we obtain the time evolution of the signal received by the antennas. The frequency upshift of the radar echo and the power received are studied to verify the feasibility of the radar detection technique.

  1. Recent advances in geologic mapping by radar

    Science.gov (United States)

    Farr, T. G.

    1984-01-01

    Quantitative techniques are available which allow the analysis of SAR images for the derivation of geological surface and process data. In conjunction with calibrated radar sensors operating at several incidence angles, wavelengths, and polarizations, the compilation of multiparameter radar signatures of lithological and geomorphic units can accordingly proceed for geological mapping in unknown areas. While radar image tone can be used in arid zones to derive surface micromorphology, heavily vegetated tropical regions require the analysis of radar image texture by means of Fourier techniques which decompose the image into bandpasses that represent different scales of texture.

  2. Resonance and aspect matched adaptive radar (RAMAR)

    CERN Document Server

    Barrett, Terence William

    2012-01-01

    The book describes a new form of radar for which the target response is frequency, i.e., resonance-dependent. The book provides both prototype designs and empirical results collected from a variety of targets. The new form of radar, called RAMAR (Resonance and Aspect Matched Adaptive Radar) advances radar - mere ranging and detection - to the level of RF spectroscopy, and permits an advance of spectroscopic methods from optical, through infra-red and into the RF spectral range. The book will describe how a target's response can be a function of frequency components in the transmitted signal's

  3. Radar network communication through sensing of frequency hopping

    Science.gov (United States)

    Dowla, Farid; Nekoogar, Faranak

    2013-05-28

    In one embodiment, a radar communication system includes a plurality of radars having a communication range and being capable of operating at a sensing frequency and a reporting frequency, wherein the reporting frequency is different than the sensing frequency, each radar is adapted for operating at the sensing frequency until an event is detected, each radar in the plurality of radars has an identification/location frequency for reporting information different from the sensing frequency, a first radar of the radars which senses the event sends a reporting frequency corresponding to its identification/location frequency when the event is detected, and all other radars in the plurality of radars switch their reporting frequencies to match the reporting frequency of the first radar upon detecting the reporting frequency switch of a radar within the communication range. In another embodiment, a method is presented for communicating information in a radar system.

  4. The NASA radar entomology program at Wallops Flight Center

    Science.gov (United States)

    Vaughn, C. R.

    1979-01-01

    NASA contribution to radar entomology is presented. Wallops Flight Center is described in terms of its radar systems. Radar tracking of birds and insects was recorded from helicopters for airspeed and vertical speed.

  5. A Parallel, High-Fidelity Radar Model

    Science.gov (United States)

    Horsley, M.; Fasenfest, B.

    2010-09-01

    Accurate modeling of Space Surveillance sensors is necessary for a variety of applications. Accurate models can be used to perform trade studies on sensor designs, locations, and scheduling. In addition, they can be used to predict system-level performance of the Space Surveillance Network to a collision or satellite break-up event. A high fidelity physics-based radar simulator has been developed for Space Surveillance applications. This simulator is designed in a modular fashion, where each module describes a particular physical process or radar function (radio wave propagation & scattering, waveform generation, noise sources, etc.) involved in simulating the radar and its environment. For each of these modules, multiple versions are available in order to meet the end-users needs and requirements. For instance, the radar simulator supports different atmospheric models in order to facilitate different methods of simulating refraction of the radar beam. The radar model also has the capability to use highly accurate radar cross sections generated by the method of moments, accelerated by the fast multipole method. To accelerate this computationally expensive model, it is parallelized using MPI. As a testing framework for the radar model, it is incorporated into the Testbed Environment for Space Situational Awareness (TESSA). TESSA is based on a flexible, scalable architecture, designed to exploit high-performance computing resources and allow physics-based simulation of the SSA enterprise. In addition to the radar models, TESSA includes hydrodynamic models of satellite intercept and debris generation, orbital propagation algorithms, optical brightness calculations, optical system models, object detection algorithms, orbit determination algorithms, simulation analysis and visualization tools. Within this framework, observations and tracks generated by the new radar model are compared to results from a phenomenological radar model. In particular, the new model will be

  6. Pocket radar guide key facts, equations, and data

    CERN Document Server

    Curry, G Richard

    2010-01-01

    ThePocket Radar Guideis a concise collection of key radar facts and important radar data that provides you with necessary radar information when you are away from your office or references. It includes statements and comments on radar design, operation, and performance; equations describing the characteristics and performance of radar systems and their components; and tables with data on radar characteristics and key performance issues.It is intended to supplement other radar information sources by providing a pocket companion to refresh memory and provide details whenever you need them such a

  7. Array-Based Ultrawideband through-Wall Radar: Prediction and Assessment of Real Radar Abilities

    Directory of Open Access Journals (Sweden)

    Nadia Maaref

    2013-01-01

    Full Text Available This paper deals with a new through-the-wall (TTW radar demonstrator for the detection and the localisation of people in a room (in a noncooperative way with the radar situated outside but in the vicinity of the first wall. After modelling the propagation through various walls and quantifying the backscattering by the human body, an analysis of the technical considerations which aims at defining the radar design is presented. Finally, an ultrawideband (UWB frequency modulated continuous wave (FMCW radar is proposed, designed, and implemented. Some representative trials show that this radar is able to localise and track moving people behind a wall in real time.

  8. Long-term mean and seasonal variation of altimetry-derived Oyashio transport across the A-line off the southeastern coast of Hokkaido, Japan

    Science.gov (United States)

    Kuroda, Hiroshi; Wagawa, Taku; Kakehi, Shigeho; Shimizu, Yugo; Kusaka, Akira; Okunishi, Takeshi; Hasegawa, Daisuke; Ito, Shin-ichi

    2017-03-01

    To understand long-term mean and seasonal variations of the Oyashio transport off the southeastern coast of Hokkaido, time series of estimated transports were generated by combining satellite altimetry and CTD data from the period 1993-2014 along a monitoring transect referred to as the ;A-line;. Linear regressions between CTD-derived geostrophic transport and altimetry-derived sea level anomaly differences were calculated by minimizing a cost function newly proposed in this study. The horizontal structure of 21-year mean transport was characterized by a southwestward flow on the continental slope (SW-1) associated with the First Oyashio Intrusion, a northeastward flow (NE-2) likely trapped against the Kuril-Kamchatka trench, a southwestward flow (SW-3) related to the Second Oyashio Intrusion, and a very stable northeastward flow (NE-4) corresponding to a combination of the Oyashio Return Flow and quasi-stationary Jet. Analysis of long-term mean monthly transports revealed four alternating flows that were present throughout all seasons of the year. The boundaries between adjacent pairs of the four flows on the A-line did not change on a seasonal timescale as much as the southernmost latitude of the First Oyashio Intrusion. At a 0-month (1-month) time lag, the sum of the SW-1, NE-2, and SW-3 (SW-1 and NE-2) transports, which corresponds to net Oyashio transport (partial net Oyashio transport related to the southernmost latitude of the First Oyashio Intrusion), was correlated with Sverdrup transport more robustly than was each of the four alternating flows. This result suggests that as the Oyashio crossed the A-line, it responded barotropically to basin-scale wind stress by adjusting transports composed of both southwestward and northeastward flows.

  9. Analysis of HLA genes and haplotypes in Ainu (from Hokkaido, northern Japan) supports the premise that they descent from Upper Paleolithic populations of East Asia.

    Science.gov (United States)

    Bannai, M; Ohashi, J; Harihara, S; Takahashi, Y; Juji, T; Omoto, K; Tokunaga, K

    2000-02-01

    The Ainu people are assumed to be the descendants of pre-agricultural native populations of northern Japan, while the majority of population of present-day Japan (Hondo-Japanese) is considered to have descended mainly from post-neolithic migrants. Sequence-level polymorphisms of the HLA-class I (HLA-A and HLA-B) genes were investigated in DNA samples of 50 Ainu living in Hidaka district, Hokkaido. HLA-A*2402, A*0201, A*0206, A*2601, A*3101, B*1501, B*5101, B*3901, and B*3501 were observed at frequencies of more than 10% and most of these have previously been found in populations of not only Asians but also North and South American Indians. A*68012, which has not so far been detected in Hondo-Japanese, was found in the Ainu (3%). On the other hand, several alleles common in Hondo-Japanese, including HLA-A*3303, A*1101, B*4403, B*5201, B*5401, B*4601, and B*0702 were infrequent in Ainu (0-1%). Correspondence and neighbor-joining analyses of various populations based on HLA-A, -B and -DRB1 gene frequencies enabled distinction between Asian, Native South American, European, and African populations. The Ainu, as well as Tlingit (Na-Dene), were placed midway between other East Asians, including Hondo Japanese, and Native South Americans (Amerindians) in the correspondence analysis. Furthermore, several HLA-A-B and HLA-B-DR-DQ haplotypes common in the Ainu, are shared with some Native American populations. These observations strongly suggest a unique place for the Ainu as descendants of some Upper Paleolithic populations of East Asia, from whom some Native Americans may have descended.

  10. Stress drops for intermediate-depth intraslab earthquakes beneath Hokkaido, northern Japan: Differences between the subducting oceanic crust and mantle events

    Science.gov (United States)

    Kita, Saeko; Katsumata, Kei

    2015-02-01

    Spatial variations in the stress drop for 1726 intermediate-depth intraslab earthquakes were examined in the subducting Pacific plate beneath Hokkaido, using precisely relocated hypocenters, the corner frequencies of events, and detailed determined geometry of the upper interface of the Pacific plate. The results show that median stress drop for intraslab earthquakes generally increases with an increase in depth from ˜10 to 157 Mpa at depths of 70-300 km. More specifically, median stress drops for events in the oceanic crust decrease (9.9-6.8 MPa) at depths of 70-120 km and increase (6.8-17 MPa) at depths of 120-170 km, whereas median stress drop for events in the oceanic mantle decrease (21.6-14.0 MPa) at depths of 70-170 km, where the geometry of the Pacific plate is well determined. The increase in stress drop with depth in the oceanic crust at depths of 120-170 km, for which several studies have shown an increase in velocity, can be explained by an increase in the velocity and a decrease in the water content due to the phase boundary with dehydration in the oceanic crust. Stress drops for events in the oceanic mantle were larger than those for events in the oceanic crust at depths of 70-120 km. Differences in both the rigidity of the rock types and in the rupture mechanisms for events between the oceanic crust and mantle could be causes for the stress drop differences within a slab.

  11. THE USE OF REMOTE SENSING, REGRESSION QUANTILES, AND GIS APPROACHES FOR MODELING OF SCALLOP LARVAE: A Case Study in Funka Bay, Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    I Nyoman Radiarta

    2011-12-01

    Full Text Available In the development of scallop cultivation in Japan, larvae collection and propagation become an important factor. Although the monitoring program has been conducted, modeling of species distribution is becoming an important tool for understanding the effects of environmental changes and resources management. This study was conducted to construct a model for providing estimation of the scallop larvae distribution in Funka Bay, Hokkaido, Japan using the integration of remote sensing, Regression Quantile (RQ and Geographic Information System (GIS-based model. Data on scallop larvae were collected during one year spawning season from April to July 2003. Environmental parameters were extracted from multi sensor remotely sensed data (chlorophyll-a and sea surface temperature and a hydrographic chart (water depth. These parameters together with larvae data were then analyzed using RQ. Finally, spatial models were constructed within a GIS by combining the RQ models with digital map of environmental parameters. The results show that the model was best explained by using only sea surface temperature. The highest larvae densities were predicted in a relatively broad distribution along with the shallow water regions (Toyoura and Sawara to Yakumo and the deeper water areas (center of the bay. The spatial model built from the RQ provided robust estimation of the scallop larvae distributions in the study area, as confirmed by model validation using independent data. These findings could contribute on the monitoring program in this region in order to distinguish the potential areas for an effective spat collection.

  12. Rates of water exsolution and magma ascent inferred from microstructures and chemical analyses of the Tokachi-Ishizawa obsidian lava, Shirataki, northern Hokkaido, Japan

    Science.gov (United States)

    Sano, Kyohei; Wada, Keiji; Sato, Eiichi

    2015-02-01

    Very few quantitative textural data exist for viscous obsidian lava eruptions, and it is still unclear from the mechanical behavior of ascending magmas if outgassing is controlled dominantly by brittle or ductile deformation. In order to obtain insights into how degassing and ascent proceed in such highly viscous magmas, we conducted textural and chemical analyses of the Tokachi-Ishizawa (TI) obsidian lava, in the Shirataki rhyolite volcanic area, northern Hokkaido, Japan, and estimated the water exsolution rate and ascent rate. The storage conditions of the TI lava are estimated from the Rhyolite-MELTS program as T = 840-860 °C and P = 50 MPa using the mineral assemblages and the chemical compositions of plagioclase phenocrysts and glass. To estimate the magma ascent rate, we measured the length, width, and number of oxide microlites using three-dimensional techniques. Textural analysis indicates that the microlite number densities (Nv [number/m3]) of oxide microlites in TI lava samples are 2.1 × 1013 to 1.4 × 1014, which correspond to water exsolution rates of 3.5 × 10- 9 to 1.7 × 10- 8 wt.%/s and ascent rates of 1.7 × 10- 6 to 1.1 × 10- 5 m/s. Together with an estimate of viscosity, the inferred ascent velocities allow us to examine the mechanical behavior of the magma in the conduit. We conclude that the development of permeability leading to outgassing is controlled by ductile deformation rather than brittle fracturing.

  13. Borrelia miyamotoi infections among wild rodents show age and month independence and correlation with Ixodes persulcatus larval attachment in Hokkaido, Japan.

    Science.gov (United States)

    Taylor, Kyle R; Takano, Ai; Konnai, Satoru; Shimozuru, Michito; Kawabata, Hiroki; Tsubota, Toshio

    2013-02-01

    To clarify how Borrelia miyamotoi is maintained in the environment in Hokkaido, we examined Ixodes persulcatus for its prevalence among wild rodents and its tick vector by detecting a portion of the borrelial flaB gene in rodent urinary bladder and blood samples, and from whole ticks. We compared B. miyamotoi infection rates to Borrelia garinii and Borrelia afzelii, which are human Lyme disease pathogens also carried by wild rodents, and which are transmitted by the same vector tick. Whereas B. garinii and B. afzelii showed age dependence of infection rates among wild rodents (18.4% and 9.9% among adults and 6.0% and 3.4% among sub-adults, respectively) when looking at urinary bladder samples, B. miyamotoi infection rates were not age dependent for either blood (4.2% among adults, and 7.9% among sub-adults) or urinary bladder samples (1.0% among adults, and 1.7% among sub-adults). Moreover, while B. garinii and B. afzelii infection rates showed increases across months (June, July [prodents with B. garinii, and July and August had higher rates than in May [prodents with B. afzelii), B. miyamotoi infection rates did not show significant month dependence. These differences in month and age dependence led us to suspect that B. miyamotoi may not develop persistent infections in wild rodents, as B. garinii and B. afzelii are thought to. Furthermore, we examined the extent of rodent exposure to I. persulcatus nymphs and larvae throughout most of the tick's active season (May through September), and determined that B. miyamotoi infection rates in sub-adult rodents were correlated with larval burden (prodents.

  14. Radar interferometry persistent scatterer technique

    CERN Document Server

    Kampes, Bert M

    2006-01-01

    Only book on Permanent Scatterer technique of radar interferometryExplains the Permanent Scatterer technique in detail, possible pitfalls, and details a newly developed stochastic model and estimator algorithm to cope with possible problems for the application of the PS techniqueThe use of Permanent Scatterer allows very precise measurements of the displacement of hundreds of points per square kilometerDescribes the only technique currently able to perform displacement measurements in the past, utilizing the ERS satellite data archive using data acquired from 1992-prese

  15. Imaging radar polarimetry - A review

    Science.gov (United States)

    Zebker, Howard A.; Van Zyl, Jakob J.

    1991-01-01

    The authors present a tutorial review of the broad sweep of topics relating to imaging radar polarimetry, ranging from mathematical foundations to hardware and from implementation approaches to signal processing and calibration. The authors examine current developments in sensor technology and implementation for recording polarimetric measurements, and describe techniques and areas of application for this form of remotely sensed data. Those aspects of ground signal processing and calibration peculiar to the polarimetric signals are addressed. Several of the currently operating instruments and some of the implementations planned for future use are discussed.

  16. Multiple frequency atmospheric radar techniques

    Science.gov (United States)

    Stitt, Gary Richard

    The use of multiple frequency coding to improve the vertical resolution of pulsed-Doppler very high frequency atmospheric radars, especially with regards to the two-frequency techniques known as frequency domain interferometry (FDI), is presented. This technique consists of transmitting alternate pulses on two distinct carrier frequencies. The two resulting time series are used to evaluate the normalized cross-correlation function, whose magnitude and phase are related to the thickness and position of a scattering layer. These same time series are also used to evaluate cross-spectra, which yield magnitude and phase values for each Doppler frequency component of the return signal.

  17. Radar Methods in Urban Environments

    Science.gov (United States)

    2016-10-26

    AFRL-AFOSR-VA-TR-2016-0344 Radar Methods in Urban Environments Arye Nehorai WASHINGTON UNIVERSITY THE Final Report 10/26/2016 DISTRIBUTION A...Methods in Urban Environments 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-11-1-0210 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Arye Nehorai 5d...Methods in Urban Environments Grant No. FA9550-11-1-0210 Final Report August 2011 – July 2016 Arye Nehorai Department of Electrical and Systems

  18. Incidence angle normalization of radar backscatter data

    Science.gov (United States)

    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...

  19. Wind energy applications of synthetic aperture radar

    DEFF Research Database (Denmark)

    Badger, Merete

    Synthetic aperture radars (SAR), mounted on satellites or aircraft, have proven useful for ocean wind mapping. Wind speeds at the height 10 m may be retrieved from measurements of radar backscatter using empirical model functions. The resulting windfields are valuable in offshore wind energy...

  20. Kharkiv Meteor Radar System (the XX Age)

    Science.gov (United States)

    Kolomiyets, S. V.

    2012-09-01

    Kharkiv meteor radar research are of historic value (Kolomiyets and Sidorov 2007). Kharkiv radar observations of meteors proved internationally as the best in the world, it was noted at the IAU General Assembly in 1958. In the 1970s Kharkiv meteor automated radar system (MARS) was recommended at the international level as a successful prototype for wide distribution. Until now, this radar system is one of the most sensitive instruments of meteor radars in the world for astronomical observations. In 2004 Kharkiv meteor radar system is included in the list of objects which compose the national property of Ukraine. Kharkiv meteor radar system has acquired the status of the important historical astronomical instrument in world history. Meteor Centre for researching meteors in Kharkiv is a analogue of the observatory and performs the same functions of a generator and a battery of special knowledge and skills (the world-famous studio). Kharkiv and the location of the instrument were brand points on the globe, as the place where the world-class meteor radar studies were carried out. They are inscribed in the history of meteor astronomy, in large letters and should be immortalized on a world-wide level.

  1. Shuttle Imaging Radar Survey Mission C

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Abstract: Spaceborne Imaging Radar-C (SIR-C) was part of an imaging radar system that was flown on board two Space Shuttle flights (9 - 20 April, 1994 and 30...

  2. Integration and Validation of Avian Radars (IVAR)

    Science.gov (United States)

    2011-08-01

    operations; 1-year visual census; multiple eBirdRad radars; fiber- optic wired LAN (planned) NAS Patuxent River, MD X B X Medium-sized air station...introduced a multibeam avian radar antenna that purports to double the beam width (from 4° to 8°), while at the same time increasing the precision of the

  3. Watchdog for ARM Radar Network Operations

    Energy Technology Data Exchange (ETDEWEB)

    2016-07-28

    WARNO is a software system designed to monitor the radars in the ARM Radar Network. It allows real time monitoring and tracking of instrument state and condition. It provides a web portal on the front end to interact with users, a REST API webpoint for interactions with third party systems, and an internal distributed architecture to allow it to be deployed at multiple sites.

  4. VAMPIRA - Radar and Infrared Propagation Synergism Trial

    NARCIS (Netherlands)

    Heemskerk, H.J.M.

    2005-01-01

    In a coastal environment simultaneous exploitation of radar and infrared sensors and multisensor fusion can overcome the difficulties imposed by the atmospheric conditions with respect to target detection/recognition/classification by the individual sensors. To investigate the so-called radar and

  5. Shuttle Imaging Radar Survey Mission C

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Spaceborne Imaging Radar-C (SIR-C) was part of an imaging radar system that was flown on board two Space Shuttle flights (9 - 20 April, 1994 and 30 September - 11...

  6. High-precision positioning of radar scatterers

    NARCIS (Netherlands)

    Dheenathayalan, P.; Small, D.; Schubert, A.; Hanssen, R.F.

    2016-01-01

    Remote sensing radar satellites cover wide areas and provide spatially dense measurements, with millions of scatterers. Knowledge of the precise position of each radar scatterer is essential to identify the corresponding object and interpret the estimated deformation. The absolute position accuracy

  7. Classification of Agricultural Crops in Radar Images

    NARCIS (Netherlands)

    Hoogeboom, P.

    1983-01-01

    For the past few years an accurate X-band SLAR system with digital recording has been available in The Netherlands. The images of this system are corrected to indicate radar backscatter coefficients (gamma) instead of arbitrary greytones. In 1980 a radar measurement campaign was organized in the

  8. Ultra-wideband radar sensors and networks

    Science.gov (United States)

    Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C

    2013-08-06

    Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.

  9. Fractal characteristics for binary noise radar waveform

    Science.gov (United States)

    Li, Bing C.

    2016-05-01

    Noise radars have many advantages over conventional radars and receive great attentions recently. The performance of a noise radar is determined by its waveforms. Investigating characteristics of noise radar waveforms has significant value for evaluating noise radar performance. In this paper, we use binomial distribution theory to analyze general characteristics of binary phase coded (BPC) noise waveforms. Focusing on aperiodic autocorrelation function, we demonstrate that the probability distributions of sidelobes for a BPC noise waveform depend on the distances of these sidelobes to the mainlobe. The closer a sidelobe to the mainlobe, the higher the probability for this sidelobe to be a maximum sidelobe. We also develop Monte Carlo framework to explore the characteristics that are difficult to investigate analytically. Through Monte Carlo experiments, we reveal the Fractal relationship between the code length and the maximum sidelobe value for BPC waveforms, and propose using fractal dimension to measure noise waveform performance.

  10. Magneto-Radar Hidden Metal Detector

    Energy Technology Data Exchange (ETDEWEB)

    McEwan, Thomas E. (Las Vegas, NV)

    2005-07-05

    A varying magnetic field excites slight vibrations in an object and a radar sensor detects the vibrations at a harmonic of the excitation frequency. The synergy of the magnetic excitation and radar detection provides increased detection range compared to conventional magnetic metal detectors. The radar rejects background clutter by responding only to reflecting objects that are vibrating at a harmonic excitation field, thereby significantly improving detection reliability. As an exemplary arrangement, an ultra-wideband micropower impulse radar (MIR) is capable of being employed to provide superior materials penetration while providing range information. The magneto-radar may be applied to pre-screening magnetic resonance imaging (MRI) patients, landmine detection and finding hidden treasures.

  11. Weather radar rainfall data in urban hydrology

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Einfalt, Thomas; Willems, Patrick

    2017-01-01

    Application of weather radar data in urban hydrological applications has evolved significantly during the past decade as an alternative to traditional rainfall observations with rain gauges. Advances in radar hardware, data processing, numerical models, and emerging fields within urban hydrology...... necessitate an updated review of the state of the art in such radar rainfall data and applications. Three key areas with significant advances over the past decade have been identified: (1) temporal and spatial resolution of rainfall data required for different types of hydrological applications, (2) rainfall...... estimation, radar data adjustment and data quality, and (3) nowcasting of radar rainfall and real-time applications. Based on these three fields of research, the paper provides recommendations based on an updated overview of shortcomings, gains, and novel developments in relation to urban hydrological...

  12. Remote sensing with laser spectrum radar

    Science.gov (United States)

    Wang, Tianhe; Zhou, Tao; Jia, Xiaodong

    2016-10-01

    The unmanned airborne (UAV) laser spectrum radar has played a leading role in remote sensing because the transmitter and the receiver are together at laser spectrum radar. The advantages of the integrated transceiver laser spectrum radar is that it can be used in the oil and gas pipeline leak detection patrol line which needs the non-contact reflective detection. The UAV laser spectrum radar can patrol the line and specially detect the swept the area are now in no man's land because most of the oil and gas pipelines are in no man's land. It can save labor costs compared to the manned aircraft and ensure the safety of the pilots. The UAV laser spectrum radar can be also applied in the post disaster relief which detects the gas composition before the firefighters entering the scene of the rescue.

  13. Numerical simulation of imaging laser radar system

    Science.gov (United States)

    Han, Shaokun; Lu, Bo; Jiang, Ming; Liu, Xunliang

    2008-03-01

    Rational and effective design of imaging laser radar systems is the key of imaging laser radar system research. Design must fully consider the interrelationship between various parameters. According to the parameters, choose suitable laser, detector and other components. To use of mathematical modeling and computer simulation is an effective imaging laser radar system design methods. This paper based on the distance equation, using the detection statistical methods, from the laser radar range coverage, detection probability, false-alarm rate, SNR to build the laser radar system mathematical models. In the process of setting up the mathematical models to fully consider the laser, atmosphere, detector and other factors on the performance that is to make the models be able to respond accurately the real situation. Based on this using C# and Matlab designed a simulation software.

  14. Radar-eddy current GPR

    Directory of Open Access Journals (Sweden)

    A. O. Abramovych

    2014-06-01

    Full Text Available Introduction. At present there are many electrical schematic metal detectors (the most common kind of ground penetrating radar, which are differ in purpose. Each scheme has its own advantages and disadvantages compared to other schemes. Designing metal detector problem of optimal selection of functional units most schemes can only work with a narrow range of special purpose units. Functional units used in circuits can be replaced by better ones, but specialization schemes do not provide such a possibility. Description of problem. Author has created a "complex for research of functional units of metal detectors" that is the universal system that meets the task. With this set of studies conducted on the practical implementation of radar-eddy current method of distinguishing non-ferrous metals (gold, copper, etc. is based. Description of method. Mathematical tools using have to be treated as a signal metal detector to distinguish metals: gold, copper and others. Conclusions. Processing of partial pulses may have information about beforehand signal loss during propagation in heterogeneous media with lossy nonuniform distribution parameters. Using eddy currents To calculate the value of the input voltage depending on the conductivity of the metal in the receiving antenna.Combining two different methods for processing the received signal theoretically it could be proved that with high probability can distinguish non-ferrous metals - gold, copper etc.

  15. Space Radar Image of Bahia

    Science.gov (United States)

    1994-01-01

    This is a color composite image of southern Bahia, Brazil, centered at 15.22 degree south latitude and 39.07 degrees west longitude. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on its 38th orbit of Earth on October 2, 1994. The image covers an area centered over the Una Biological Reserve, one the largest protected areas in northeastern Brazil. The 7,000-hectare reserve is administered by the Brazilian Institute for the Environment and is part of the larger Atlantic coastal forest, a narrow band of rain forest extending along the eastern coast of Brazil. The Atlantic coastal forest of southern Bahia is one of the world's most threatened and diverse ecosystems. Due to widespread settlement, only 2 to 5 percent of the original forest cover remains. Yet the region still contains an astounding variety of plants and animals, including a large number of endemic species. More than half of the region's tree species and 80 percent of its animal species are indigenous and found nowhere else on Earth. The Una Reserve is also the only federally protected habitat for the golden-headed lion tamarin, the yellow-breasted capuchin monkey and many other endangered species. In the past few years, scientists from Brazilian and international conservation organizations have coordinated efforts to study the biological diversity of this region and to develop practical and economically viable options for preserving the remaining primary forests in southern Bahia. The shuttle imaging radar is used in this study to identify various land uses and vegetation types, including remaining patches of primary forest, cabruca forest (cacao planted in the understory of the native forest), secondary forest, pasture and coastal mangrove. Standard remote-sensing technology that relies on light reflected from the forest canopy cannot accurately distinguish between cabruca and undisturbed forest. Optical remote sensing is also

  16. Radar fall detectors: a comparison

    Science.gov (United States)

    Erol, Baris; Amin, Moeness; Ahmad, Fauzia; Boashash, Boualem

    2016-05-01

    Falls are a major cause of accidents in elderly people. Even simple falls can lead to severe injuries, and sometimes result in death. Doppler fall detection has drawn much attention in recent years. Micro-Doppler signatures play an important role for the Doppler-based radar systems. Numerous studies have demonstrated the offerings of micro-Doppler characteristics for fall detection. In this respect, a plethora of micro-Doppler signature features have been proposed, including those stemming from speech recognition and wavelet decomposition. In this work, we consider four different sets of features for fall detection. These can be categorized as spectrogram based features, wavelet based features, mel-frequency cepstrum coefficients, and power burst curve features. Support vector machine is employed as the classifier. Performance of the respective fall detectors is investigated using real data obtained with the same radar operating resources and under identical sensing conditions. For the considered data, the spectrogram based feature set is shown to provide superior fall detection performance.

  17. Radar

    DEFF Research Database (Denmark)

    Nielsen, Tom

    2009-01-01

    Bidrag til arkitektens opgørelse (baseret på en række forskellige indlæg) over hvor dansk arkitektur står, med korte bud på spørgsmålene: Kan man ud over stedsanknytningen tale om en særlig dansk arkitektur?, Hvad er dansk arkitekturs største kvalitet, vores vigtigste force? og Hvad er dansk arki...

  18. Composite technology in radar equipment. Dopler Meteo radar reflector device

    Directory of Open Access Journals (Sweden)

    A. V. Shumov

    2014-01-01

    Full Text Available The article is devoted features of the application composite materials in radar technology for example adjustment of the development technology of the reflector antenna device DMRL-S - radar for monitoring meteorological conditions.Russian and foreign analogues DMRL-S are made of aluminum, which no longer meets modern requirements for strength and weight. Also aluminum reflectors are not temperature stable. Composite materials are characterized by higher values of specific characteristics: temporary resistance, endurance limit, stiffness, elastic modulus, and less prone to cracking. The use of such materials improves the strength, rigidity and durability.For the manufacture of the DMRL-C reflector used composite materials based on epoxy resins reinforced with fiberglass (both unidirectional and woven. To increase the rigidity and weight reflector is made in the form of three-layer sandwich fiberglass panels with honeycomb core variable height. Design work was carried out in a CAD Siemens NX8.0 / Unigraphics, through which was established mathematical model layered reflector, as well as all accessories used in the manufacture. With the program NX Nastran was held strength calculation and analysis of stiffness on the finite element method.After the manufacture of the product, we measured the standard deviation of the working surface of the reflector from the theoretical surface using a three-dimensional laser scanner. Measurements were made at different angular positions of the reflector, and when loading. It is shown that the maximum strain in the operating modes of operation across the surface of the product does not exceed 4%, which will provide the most accurate operation of the product in any position of the antenna system.As a result of this work reflector design was developed, created and verified by experimental data calculation model. Reflector antenna device of the DMRL-S was manufactured and tested. The reflector was made of reinforced

  19. Decision Tool for optimal deployment of radar systems

    NARCIS (Netherlands)

    Vogel, M.H.

    1995-01-01

    A Decision Tool for air defence is presented. This Decision Tool, when provided with information about the radar, the environment, and the expected class of targets, informs the radar operator about detection probabilities. This assists the radar operator to select the optimum radar parameters. n

  20. The use of radar for bathymetry in shallow seas

    NARCIS (Netherlands)

    Greidanus, H.

    1997-01-01

    The bottom topography in shallow seas can be observed by air- and space borne radar. The paper reviews the radar imaging mechanism, and discusses the possibilities and limitations for practical use of radar in bathymetric applications, including the types of radar instruments available for this

  1. Real-time human walking estimation with radar

    NARCIS (Netherlands)

    Dorp, Ph. van; Groen, F.C.A.

    2003-01-01

    Radars can be used to observe persons. Animation of an observed human on the basis of Frequency Modulated Continuous Wave (FMCW) radar measurements in virtual reality considerably facilitates the interpretation of the radar measurements. These radar measurements give detailed information of the moti

  2. Decision Tool for optimal deployment of radar systems

    NARCIS (Netherlands)

    Vogel, M.H.

    1995-01-01

    A Decision Tool for air defence is presented. This Decision Tool, when provided with information about the radar, the environment, and the expected class of targets, informs the radar operator about detection probabilities. This assists the radar operator to select the optimum radar parameters. n th

  3. Foliage penetration radar detection and characterization of objects under trees

    CERN Document Server

    Davis, Mark

    2011-01-01

    This book covers all aspects of foliage penetration (FOPEN) radar, concentrating on both airborne military radar systems as well as earth resource mapping radars. It is the first concise and thorough treatment of FOPEN, covering the results of a decade-long investment by DARPA in characterizing foliage and earth surface with ultrawideband UHF and VHF synthetic aperture radar (SAR).

  4. Passive Multistatic Detection of Maritime Targets using Opportunistic Radars

    Science.gov (United States)

    2014-03-01

    optimal configuration using MATLAB simulation. The simulation results are obtained using actual system parameters extracted from civil marine radar ...Bistatic Radar . Norwood, MA: Artech House, Technology Service Corporation, p. 1, 1995. [2] D. C. Jenn, Radar and Laser Cross Section Engineering...MULTISTATIC DETECTION OF MARITIME TARGETS USING OPPORTUNISTIC RADARS by Chong Sze Sing March 2014 Thesis Advisor: Herschel H. Loomis Co-Advisor

  5. Pedestrian recognition using automotive radar sensors

    Science.gov (United States)

    Bartsch, A.; Fitzek, F.; Rasshofer, R. H.

    2012-09-01

    The application of modern series production automotive radar sensors to pedestrian recognition is an important topic in research on future driver assistance systems. The aim of this paper is to understand the potential and limits of such sensors in pedestrian recognition. This knowledge could be used to develop next generation radar sensors with improved pedestrian recognition capabilities. A new raw radar data signal processing algorithm is proposed that allows deep insights into the object classification process. The impact of raw radar data properties can be directly observed in every layer of the classification system by avoiding machine learning and tracking. This gives information on the limiting factors of raw radar data in terms of classification decision making. To accomplish the very challenging distinction between pedestrians and static objects, five significant and stable object features from the spatial distribution and Doppler information are found. Experimental results with data from a 77 GHz automotive radar sensor show that over 95% of pedestrians can be classified correctly under optimal conditions, which is compareable to modern machine learning systems. The impact of the pedestrian's direction of movement, occlusion, antenna beam elevation angle, linear vehicle movement, and other factors are investigated and discussed. The results show that under real life conditions, radar only based pedestrian recognition is limited due to insufficient Doppler frequency and spatial resolution as well as antenna side lobe effects.

  6. Using phase for radar scatterer classification

    Science.gov (United States)

    Moore, Linda J.; Rigling, Brian D.; Penno, Robert P.; Zelnio, Edmund G.

    2017-04-01

    Traditional synthetic aperture radar (SAR) systems tend to discard phase information of formed complex radar imagery prior to automatic target recognition (ATR). This practice has historically been driven by available hardware storage, processing capabilities, and data link capacity. Recent advances in high performance computing (HPC) have enabled extremely dense storage and processing solutions. Therefore, previous motives for discarding radar phase information in ATR applications have been mitigated. First, we characterize the value of phase in one-dimensional (1-D) radar range profiles with respect to the ability to correctly estimate target features, which are currently employed in ATR algorithms for target discrimination. These features correspond to physical characteristics of targets through radio frequency (RF) scattering phenomenology. Physics-based electromagnetic scattering models developed from the geometrical theory of diffraction are utilized for the information analysis presented here. Information is quantified by the error of target parameter estimates from noisy radar signals when phase is either retained or discarded. Operating conditions (OCs) of signal-tonoise ratio (SNR) and bandwidth are considered. Second, we investigate the value of phase in 1-D radar returns with respect to the ability to correctly classify canonical targets. Classification performance is evaluated via logistic regression for three targets (sphere, plate, tophat). Phase information is demonstrated to improve radar target classification rates, particularly at low SNRs and low bandwidths.

  7. Radar reconnaissance of near-Earth asteroids

    Science.gov (United States)

    Ostro, Steven J.; Giorgini, Jon D.; Benner, Lance A. M.

    2007-05-01

    Radar is a uniquely powerful source of information about near-Earth asteroid (NEA) physical properties and orbits. Measurements of the distribution of echo power in time delay (range) and Doppler frequency (radial velocity) constitute two-dimensional images that can provide spatial resolution finer than a decameter. The best radar images reveal geologic details, including craters and blocks. Radar wavelengths (13 cm at Arecibo, 3.5 cm at Goldstone) are sensitive to the bulk density (a joint function of mineralogy and porosity) and the degree of decimeter-scale structural complexity of the uppermost meter or so of the surface. Radar can determine the masses of binary NEAs via Kepler's third law and of solitary NEAs via measurement of the Yarkovsky acceleration. With adequate orientational coverage, a sequence of images can be used to construct a three-dimensional model, to define the rotation state, to determine the distribution of radar surface properties, and to constrain the internal density distribution. As of mid 2006, radar has detected echoes from 193 NEAs, of which 107 are designated Potentially Hazardous Asteroids. Radar has revealed both stony and metallic objects, principal-axis and non-principal-axis rotators, smooth and extremely rough surfaces, objects that appear to be monolithic fragments and objects likely to be nearly strengthless gravitational aggregates, spheroids and highly elongated shapes, contact-binary shapes, and binary systems. Radar can add centuries to the interval over which close Earth approaches can accurately be predicted, significantly refining collision probability estimates compared to those based on optical astrometry alone. If a small body is on course for a collision with Earth in this century, delay-Doppler radar echoes could almost immediately let us recognize this by distinguishing between an impact trajectory and a near miss, and would dramatically reduce the difficulty and cost of any effort to prevent the collision.

  8. Polarization changing technique in macrocosm and it's application to radar

    Institute of Scientific and Technical Information of China (English)

    潘健; 毛二可

    2004-01-01

    A new model of air-surveillance radar (named polarization changing in macrocosm radar: PCM radar), which makes use of the polarization changing technique in macrocosm, is presented in this paper. On basis of careful selection of representative 98 states of polarization in macrocosm, PCM radar can not only perform transmitting and receiving polarization matching for various targets, consequently make full use of transmitting and receiving signals of radar, but also improve the capability against active interference and jamming. Experimental test in air defense early-warning radar system demonstrates that it can effectively enhance radar performance.

  9. Potency of a vaccine prepared from A/swine/Hokkaido/2/1981 (H1N1 against A/Narita/1/2009 (H1N1 pandemic influenza virus strain

    Directory of Open Access Journals (Sweden)

    Okamatsu Masatoshi

    2013-02-01

    Full Text Available Abstract Background The pandemic 2009 (H1N1 influenza virus has spread throughout the world and is now causing seasonal influenza. To prepare for the emergence of pandemic influenza, we have established a library of virus strains isolated from birds, pigs, and humans in global surveillance studies. Methods Inactivated whole virus particle (WV and ether-split (ES vaccines were prepared from an influenza virus strain, A/swine/Hokkaido/2/1981 (H1N1, from the library and from A/Narita/1/2009 (H1N1 pandemic strain. Each of the vaccines was injected subcutaneously into mice and their potencies were evaluated by challenge with A/Narita/1/2009 (H1N1 virus strain in mice. Results A/swine/Hokkaido/2/81 (H1N1, which was isolated from the lung of a diseased piglet, was selected on the basis of their antigenicity and growth capacity in embryonated chicken eggs. Two injections of the WV vaccine induced an immune response in mice, decreasing the impact of disease caused by the challenge with A/Narita/1/2009 (H1N1, as did the vaccine prepared from the homologous strain. Conclusion The WV vaccine prepared from an influenza virus in the library is useful as an emergency vaccine in the early phase of pandemic influenza.

  10. Canadian Meteor Orbit Radar (CMOR

    Directory of Open Access Journals (Sweden)

    A. R. Webster

    2004-01-01

    Full Text Available The radar system described here (CMOR comprises a basic 5-element receiving system, co-located with a pulsed transmitter, specifically designed to observe meteor echoes and to determine their position in space with an angular resolution of ~1° and a radial resolution of ~3 km. Two secondary receiving sites, a few km distant and arranged to form approximately a right angle with the base station, allow the determination of the velocity (speed and direction of the meteor that, together with the time of occurrence, lead to an estimate of the orbit of the original meteoroid. Some equipment details are presented along with a method used to determine the orbits. Representative echoes are shown and observations on the 2002 Leonid shower presented.

  11. Navigator alignment using radar scan

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W.; Marquette, Brandeis

    2016-04-05

    The various technologies presented herein relate to the determination of and correction of heading error of platform. Knowledge of at least one of a maximum Doppler frequency or a minimum Doppler bandwidth pertaining to a plurality of radar echoes can be utilized to facilitate correction of the heading error. Heading error can occur as a result of component drift. In an ideal situation, a boresight direction of an antenna or the front of an aircraft will have associated therewith at least one of a maximum Doppler frequency or a minimum Doppler bandwidth. As the boresight direction of the antenna strays from a direction of travel at least one of the maximum Doppler frequency or a minimum Doppler bandwidth will shift away, either left or right, from the ideal situation.

  12. Phased-MIMO Radar: A Tradeoff Between Phased-Array and MIMO Radars

    CERN Document Server

    Hassanien, Aboulnasr

    2009-01-01

    We propose a new technique for multiple-input multiple-output (MIMO) radar with colocated antennas which we call phased-MIMO radar. The new technique enjoys the advantages of MIMO radar without sacrificing the main advantage of phased-array radar which is the coherent processing gain at the transmitting side. The essence of the proposed technique is to partition the transmitting array into a number of subarrays that are allowed to overlap. Then, each subarray is used to coherently transmit a waveform which is orthogonal to the waveforms transmitted by other subarrays. Coherent processing gain can be achieved by designing a weight vector for each subarray to form a beam towards a certain direction in space. Moreover, the subarrays are combined jointly to form a MIMO radar resulting in higher resolution capabilities. The substantial improvements offered by the proposed phased-MIMO radar technique as compared to previous techniques are demonstrated analytically and by simulations through analysis of the correspo...

  13. A Scanning Microwave Radar and Radiometer

    DEFF Research Database (Denmark)

    Skou, Niels

    1995-01-01

    The Scanning Microwave Radar and Radiometer (SMRR) is a line scanner featuring a combined radar and radiometer system operating around 35 and 94 GHz. The layout of the SMRR is shown. The 2 offset antenna parabolas scan in synchronism, the receiver antenna has the highest gain in order to ensure...... that footprints are identical for the radar and the radiometer. The instrument will be flown in a pod under a Gulfstream G3 normally cruising with 240 m/sec at 12500 m, and will thus be able to sense clouds and precipitation from above...

  14. The Italian involvement in Cassini radar

    Science.gov (United States)

    Nirchio, F.; Pernice, B.; Borgarelli, L.; Dionisio, C.

    1991-12-01

    The Radio Frequency Electronic Subsystem (RFES) of the Cassini radar is described. The requirements of the Cassini radar are summarized. The design parameters taken into consideration in developing the RFES are described. The RFES interfaces with the High Gain Antenna (HGA) for signal transmission and reception. The operational parameters of the Cassini radar are presented. The front end electronics (FEE), microwave receiver (MR), high power amplifier (HPA), frequency generator (FG), digital chip generator (DCG), Chirp Up Converter and Amplifier (CUCA) and power supply of the RFES are described.

  15. Radar signal processing and its applications

    CERN Document Server

    Hummel, Robert; Stoica, Petre; Zelnio, Edmund

    2003-01-01

    Radar Signal Processing and Its Applications brings together in one place important contributions and up-to-date research results in this fast-moving area. In twelve selected chapters, it describes the latest advances in architectures, design methods, and applications of radar signal processing. The contributors to this work were selected from the leading researchers and practitioners in the field. This work, originally published as Volume 14, Numbers 1-3 of the journal, Multidimensional Systems and Signal Processing, will be valuable to anyone working or researching in the field of radar signal processing. It serves as an excellent reference, providing insight into some of the most challenging issues being examined today.

  16. Pitfalls and possibilities of radar compressive sensing.

    Science.gov (United States)

    Goodman, Nathan A; Potter, Lee C

    2015-03-10

    In this paper, we consider the application of compressive sensing (CS) to radar remote sensing applications. We survey a suite of practical system-level issues related to the compression of radar measurements, and we advocate the consideration of these issues by researchers exploring potential gains of CS in radar applications. We also give abbreviated examples of decades-old radio-frequency (RF) practices that already embody elements of CS for relevant applications. In addition to the cautionary implications of system-level issues and historical precedents, we identify several promising results that RF practitioners may gain from the recent explosion of CS literature.

  17. Radar, sonar, and holography an introduction

    CERN Document Server

    Kock, Winston E

    1974-01-01

    Radar, Sonar, and Holography: An Introduction provides an introduction to the technology of radar and sonar. Because the new science of holography is affecting both these fields quite strongly, the book includes an explanation of the fundamental principles underlying this new art (including the subjects of wave coherence, interference, and diffraction) and of the hologram process itself. Finally, numerous examples are discussed which show how holography is providing new horizons to radar and sonar systems. The book thus also provides a simple approach to the new technology of holography. The

  18. Robust adaptive beamforming for MIMO monopulse radar

    Science.gov (United States)

    Rowe, William; Ström, Marie; Li, Jian; Stoica, Petre

    2013-05-01

    Researchers have recently proposed a widely separated multiple-input multiple-output (MIMO) radar using monopulse angle estimation techniques for target tracking. The widely separated antennas provide improved tracking performance by mitigating complex target radar cross-section fades and angle scintillation. An adaptive array is necessary in this paradigm because the direct path from any transmitter could act as a jammer at a receiver. When the target-free covariance matrix is not available, it is critical to include robustness into the adaptive beamformer weights. This work explores methods of robust adaptive monopulse beamforming techniques for MIMO tracking radar.

  19. Satellite radar for monitoring forest resources

    Science.gov (United States)

    Hoffer, Roger M.; Lee, Kyu-Sung

    1990-01-01

    An evaluation is made of the computer analysis results of a study which used Seasat satellite radar data obtained in 1978 and Shuttle Imaging Radar-B data obtained in 1984. The change-detection procedures employed demonstrate that deforestation and reforestation activities can be effectively monitored on the basis of radar data gathered at satellite altitudes. The computer-processing techniques applied to the data encompassed (1) overlay display, (2) ratios, (3) differences, (4) principal-component analysis, and (5) classification; of these, overlay display is noted to quickly and easily yield a qualitative display of the multidate data.

  20. Noise radar with broadband microwave ring correlator

    Science.gov (United States)

    Susek, Waldemar; Stec, Bronislaw

    2011-06-01

    A principle of quadrature correlation detection of noise signals using an analog broadband microwave correlator is presented in the paper. Measurement results for the correlation function of noise signals are shown and application of such solution in the noise radar for precise determination of distance changes and velocity of these changes is also presented. Results for short range noise radar operation are presented both for static and moving objects. Experimental results using 2,6 - 3,6 GHz noise like waveform for the signal from a breathing human is presented. Conclusions and future plans for applications of presented detection technique in broadband noise radars bring the paper to an end.

  1. Highly Integrated Radar Sensor-on-Chip

    Science.gov (United States)

    Mende, Ralph

    2012-05-01

    A highly integrated 24 GHz radar sensor is presented, based on a Radio Frequency Integrated Circuit (RFIC) which was specifically developed for a Frequency Modulated Shift Keying (FMSK) based Radar system design. Antenna, waveform, the Radio Frequency (RF) and Digital Signal Processor (DSP) module, the software design, cost and performance aspects will be described. The significant technical and economical advantages of the implemented Silicon-Germanium (SiGe) Bipolar CMOS (BiCMOS) transceiver are demonstrated. Some automotive and other applications based on this technology and new radar system design will be explained.

  2. Modeling Characteristics Of Surfaces For Radar Polarimetry

    Science.gov (United States)

    Van Zyl, Jakob J.; Zebker, Howard A.; Durden, Stephen L.

    1992-01-01

    Paper reviews mathematical models of polarimetric radar backscattering characteristics of various types of terrain; forests, grasslands, and lava fields. Represents approach to imaging radar polarimetry in which one accumulates models predicting realistic polarization signatures and represent distinct scattering processes, without attempting full vector solutions of Maxwell's equations in all cases. Idea to develop ability to invert models to identify unknown terrain depicted in polarimetric radar images. Describes models, major scattering characteristics predicted by models, and interpretation of characteristics in terms of dominant scattering mechanisms. Models predict realistic polarization signatures.

  3. Radar Exploration of Cometary Nuclei

    Science.gov (United States)

    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.

  4. Age and speciation of iodine in groundwater and mudstones of the Horonobe area, Hokkaido, Japan: Implications for the origin and migration of iodine during basin evolution

    Science.gov (United States)

    Togo, Yoko S.; Takahashi, Yoshio; Amano, Yuki; Matsuzaki, Hiroyuki; Suzuki, Yohey; Terada, Yasuko; Muramatsu, Yasuyuki; Ito, Kazumasa; Iwatsuki, Teruki

    2016-10-01

    This paper reports the concentration, speciation and isotope ratio (129I/127I) of iodine from both groundwater and host rocks in the Horonobe area, northern Hokkaido, Japan, to clarify the origin and migration of iodine in sedimentary rocks. Cretaceous to Quaternary sedimentary rocks deposited nearly horizontally in Tenpoku Basin and in the Horonobe area were uplifted above sea level during active tectonics to form folds and faults in the Quaternary. Samples were collected from the Pliocene Koetoi and late Miocene Wakkanai formations (Fms), which include diatomaceous and siliceous mudstones. The iodine concentration in groundwater, up to 270 μmol/L, is significantly higher than that of seawater, with the iodine enrichment factor relative to seawater reaching 800-1500. The iodine concentration in the rocks decreases from the Koetoi to Wakkanai Fms, suggesting that iodine was released into the water from the rocks of deeper formations. The iodine concentration in the rocks is sufficiently high for forming iodine-rich groundwater as found in this area. X-ray absorption near edge structure (XANES) analysis shows that iodine exists as organic iodine and iodide (I-) in host rocks, whereas it exists mainly as I- in groundwater. The isotope ratio is nearly constant for iodine in the groundwater, at [0.11-0.23] × 10-12, and it is higher for iodine in rocks, at [0.29-1.1] × 10-12, giving iodine ages of 42-60 Ma and 7-38 Ma, respectively. Some iodine in groundwater must have originated from Paleogene and even late Cretaceous Fms, which are also considered as possible sources of oil and gas, in view of the old iodine ages of the groundwater. The iodine ages of the rocks are older than the depositional ages, implying that the rocks adsorbed some iodine from groundwater, which was sourced from greater depths. The iodine concentration in groundwater decreases with decreasing chlorine concentration due to mixing of iodine-rich connate water and meteoric water. A likely scenario

  5. Comparison of Two Detection Combination Algorithms for Phased Array Radars

    Science.gov (United States)

    2015-07-01

    weapon guidance. It can also be used effectively for secure communications [1]. In an MFR, the radar surveillance plays a critical role to optimize the...horizon/surface search, detection confirmation, multi-target tracking and cued search. The simulated radar has an aperture of 1 m2. The antennas...Comparison of Two Detection Combination Algorithms for Phased Array Radars Zhen Ding and Peter Moo Wide Area Surveillance Radar Group Radar

  6. Using doppler radar images to estimate aircraft navigational heading error

    Science.gov (United States)

    Doerry, Armin W [Albuquerque, NM; Jordan, Jay D [Albuquerque, NM; Kim, Theodore J [Albuquerque, NM

    2012-07-03

    A yaw angle error of a motion measurement system carried on an aircraft for navigation is estimated from Doppler radar images captured using the aircraft. At least two radar pulses aimed at respectively different physical locations in a targeted area are transmitted from a radar antenna carried on the aircraft. At least two Doppler radar images that respectively correspond to the at least two transmitted radar pulses are produced. These images are used to produce an estimate of the yaw angle error.

  7. Volcanic deformation of Atosanupuri volcanic complex in the Kussharo caldera, Japan, from 1993 to 2016 revealed by JERS-1, ALOS, and ALOS-2 radar interferometry

    Science.gov (United States)

    Fujiwara, Satoshi; Murakami, Makoto; Nishimura, Takuya; Tobita, Mikio; Yarai, Hiroshi; Kobayashi, Tomokazu

    2017-06-01

    A series of uplifts and subsidences of a volcanic complex in the Kussharo caldera in eastern Hokkaido (Japan) has been revealed by interferometric analysis using archived satellite synthetic aperture radar data. A time series of interferograms from 1993 to 1998 showed the temporal evolution of a ground deformation process. The horizontal dimension of the deformation field was about 10 km in diameter, and the maximum amplitude of the deformation was >20 cm. Uplift started in 1994, and concurrent earthquake swarm activity was observed around the uplift area; however, no other phenomena were observed during this period. A subsidence process then followed, with the shape of the deformation forming a mirror image of the uplift. Model simulations suggest deformation was caused by a source at the depth of about 6 km and that the position of the source remained static throughout the episode. Subsidence of the volcanic complex was also observed by another satellite from 2007 to 2010, and likely continued for more than 10 years. In addition to the main uplift-subsidence sequence, small deformation patterns with short spatial wavelengths were observed at the center of the deforming area. Data from three satellites recorded small-scale subsidence of the Atosanupuri and Rishiri lava domes at a constant rate of approx. 1 cm/year from 1993 to 2016.[Figure not available: see fulltext.

  8. Synthetic impulse and aperture radar (SIAR) a novel multi-frequency MIMO radar

    CERN Document Server

    Chen, Baixiao

    2014-01-01

    Analyzes and discusses the operating principle, signal processing method, and experimental results of this advanced radar technology This book systematically discusses the operating principle, signal processing method, target measurement technology, and experimental results of a new kind of radar called synthetic impulse and aperture radar (SIAR). The purpose is to help readers acquire an insight into the concept and principle of the SIAR, to know its operation mode, signal processing method, the difference between the traditional radar and itself, the designing ideals, and the developing me

  9. Validation of GPM Ka-Radar Algorithm Using a Ground-based Ka-Radar System

    Science.gov (United States)

    Nakamura, Kenji; Kaneko, Yuki; Nakagawa, Katsuhiro; Furukawa, Kinji; Suzuki, Kenji

    2016-04-01

    GPM led by the Japan Aerospace Exploration Agency (JAXA) and the National Aeronautics and Space Administration of US (NASA) aims to observe global precipitation. The core satellite is equipped with a microwave radiometer (GMI) and a dual-frequency radar (DPR) which is the first spaceborne Ku/Ka-band dual-wavelength radar dedicated for precipitation measurement. In the DPR algorithm, measured radar reflectivity is converted to effective radar reflectivity by estimating the rain attenuation. Here, the scattering/attenuation characteristics of Ka-band radiowaves are crucial, particularly for wet snow. A melting layer observation using a dual Ka-band radar system developed by JAXA was conducted along the slope of Mt. Zao in Yamagata Prefecture, Japan. The dual Ka-band radar system consists of two nearly identical Ka-band FM-CW radars, and the precipitation systems between two radars were observed in opposite directions. From this experiment, equivalent radar reflectivity (Ze) and specific attenuation (k) were obtained. The experiments were conducted for two winter seasons. During the data analyses, it was found that k estimate easily fluctuates because the estimate is based on double difference calculation. With much temporal and spatial averaging, k-Ze relationship was obtained for melting layers. One of the results is that the height of the peak of k seems slightly higher than that of Ze. The results are compared with in-situ precipitation particle measurements.

  10. Investigating nearby exoplanets via interstellar radar

    Science.gov (United States)

    Scheffer, Louis K.

    2014-01-01

    Interstellar radar is a potential intermediate step between passive observation of exoplanets and interstellar exploratory missions. Compared with passive observation, it has the traditional advantages of radar astronomy. It can measure surface characteristics, determine spin rates and axes, provide extremely accurate ranges, construct maps of planets, distinguish liquid from solid surfaces, find rings and moons, and penetrate clouds. It can do this even for planets close to the parent star. Compared with interstellar travel or probes, it also offers significant advantages. The technology required to build such a radar already exists, radar can return results within a human lifetime, and a single facility can investigate thousands of planetary systems. The cost, although too high for current implementation, is within the reach of Earth's economy.

  11. Snowballing and flying under the radar

    DEFF Research Database (Denmark)

    Pötz, Katharina Anna; Hjortsø, Carsten Nico Portefée

    2013-01-01

    management and venture development paths. More specifically, flying under radar in terms of operating under lower institutional requirements, and slowly accumulating resources (snowballing) are major leveraging strategies. We integrate our results into a hypothesized framework for resource management in East...

  12. Tomographic Techniques for Radar Ice Sounding

    DEFF Research Database (Denmark)

    Nielsen, Ulrik

    AbstractLow frequency radars, also known as sounders, can be used for subsurfacemeasurements of Earth’s massive ice sheets. Radar data are essential toimproving ice sheet models for better prediction of the response of theseice sheets to global climate change. While airborne sounders are neededfor...... challenge. This dissertation deals with tomographic techniques based on multiphase-center radars that represent state-of-the-art technology within thefield of ice sounding. The use of advanced tomographic processing forclutter suppression is investigated, which up to this point has beenlargely unexplored...... acquired withthe POLarimetric Airborne Radar Ice Sounder (POLARIS), single-passtomographic surface clutter suppression capabilities are demonstratedfor the system. Using repeat-pass POLARIS data, a method based ondata-driven DOA estimation is used to show an along-track variation ofthe effective scattering...

  13. Space Compatible Radar Absorbing Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase 1 project shall investigate novel radar absorbing materials (RAM) for use in space or simulated space environments. These materials are lightweight...

  14. Probabilistic forecasts based on radar rainfall uncertainty

    Science.gov (United States)

    Liguori, S.; Rico-Ramirez, M. A.

    2012-04-01

    The potential advantages resulting from integrating weather radar rainfall estimates in hydro-meteorological forecasting systems is limited by the inherent uncertainty affecting radar rainfall measurements, which is due to various sources of error [1-3]. The improvement of quality control and correction techniques is recognized to play a role for the future improvement of radar-based flow predictions. However, the knowledge of the uncertainty affecting radar rainfall data can also be effectively used to build a hydro-meteorological forecasting system in a probabilistic framework. This work discusses the results of the implementation of a novel probabilistic forecasting system developed to improve ensemble predictions over a small urban area located in the North of England. An ensemble of radar rainfall fields can be determined as the sum of a deterministic component and a perturbation field, the latter being informed by the knowledge of the spatial-temporal characteristics of the radar error assessed with reference to rain-gauges measurements. This approach is similar to the REAL system [4] developed for use in the Southern-Alps. The radar uncertainty estimate can then be propagated with a nowcasting model, used to extrapolate an ensemble of radar rainfall forecasts, which can ultimately drive hydrological ensemble predictions. A radar ensemble generator has been calibrated using radar rainfall data made available from the UK Met Office after applying post-processing and corrections algorithms [5-6]. One hour rainfall accumulations from 235 rain gauges recorded for the year 2007 have provided the reference to determine the radar error. Statistics describing the spatial characteristics of the error (i.e. mean and covariance) have been computed off-line at gauges location, along with the parameters describing the error temporal correlation. A system has then been set up to impose the space-time error properties to stochastic perturbations, generated in real-time at

  15. Space-Qualifiable Digital Radar Transceiver Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Historically, radar systems have tended to be either large, complex, power-hungry, purpose-built systems, or extremely simple systems of limited capability. More...

  16. 3D Ground Penetrating Imaging Radar

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    GPiR (ground-penetrating imaging radar) is a new technology for mapping the shallow subsurface, including society’s underground infrastructure. Applications for this technology include efficient and precise mapping of buried utilities on a large scale.

  17. Physical working principles of medical radar.

    Science.gov (United States)

    Aardal, Øyvind; Paichard, Yoann; Brovoll, Sverre; Berger, Tor; Lande, Tor Sverre; Hamran, Svein-Erik

    2013-04-01

    There has been research interest in using radar for contactless measurements of the human heartbeat for several years. While many systems have been demonstrated, not much attention have been given to the actual physical causes of why this work. The consensus seems to be that the radar senses small body movements correlated with heartbeats, but whether only the movements of the body surface or reflections from internal organs are also monitored have not been answered definitely. There has recently been proposed another theory that blood perfusion in the skin could be the main reason radars are able to detect heartbeats. In this paper, an experimental approach is given to determine the physical causes. The measurement results show that it is the body surface reflections that dominate radar measurements of human heartbeats.

  18. Investigating Nearby Exoplanets via Interstellar Radar

    CERN Document Server

    Scheffer, Louis K

    2013-01-01

    Interstellar radar is a potential intermediate step between passive observation of exoplanets and interstellar exploratory missions. Compared to passive observation, it has the traditional advantages of radar astronomy. It can measure surface characteristics, determine spin rates and axes, provide extremely accurate ranges, construct maps of planets, distinguish liquid from solid surfaces, find rings and moons, and penetrate clouds. It can do this even for planets close to the parent star. Compared to interstellar travel or probes, it also offers significant advantages. The technology required to build such a radar already exists, radar can return results within a human lifetime, and a single facility can investigate thousands of planetary systems. The cost, although high, is within the reach of Earth's economy, so it is cheaper as well.

  19. Lunar Radar Cross Section at Low Frequency

    Science.gov (United States)

    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. A MIMO FMCW radar approach to HFSWR

    Science.gov (United States)

    Hinz, J. O.; Zölzer, U.

    2011-07-01

    In this paper we propose one possible approach how to apply the concept of multiple-input multiple-output (MIMO) to monostatic Frequency Modulated Continuous Wave (FMCW) High-Frequency Surface Wave Radar (HFSWR) in a maritime environment. Common tasks for a HFSWR are sea-state monitoring and ship detection, where our focus is on ship detection. A limiting factor in HFSWR is the available bandwidth, which is inversely proportional to the range resolution capability of the radar and typical below 100 kHz. The question is how to extend or combine a conventional single-input multiple-output (SIMO) FMCW phased-array type radar with stretch processing and the colocated MIMO concept to "reuse" the very limited HF radar band resources. Another important question to answer is how MIMO FMCW waveforms can be separated at the receiver.

  1. Identifying structural damage with ground penetrating radar

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2008-07-01

    Full Text Available Ground penetrating radar (GPR) and electrical resistance tomography (ERT) surveys were conducted in an urban environment in an attempt to identify the cause of severe structural damage to a historically significant residential property...

  2. Radar Training Facility Local Area Network

    Data.gov (United States)

    Department of Transportation — The RTF LAN system provides a progressive training environment for initial and refresher radar training qualification for new and re-hired FAA employees. Its purpose...

  3. Synthetic Aperture Radar Missions Study Report

    Science.gov (United States)

    Bard, S.

    2000-01-01

    This report reviews the history of the LightSAR project and summarizes actions the agency can undertake to support industry-led efforts to develop an operational synthetic aperture radar (SAR) capability in the United States.

  4. Airborne ground penetrating radar: practical field experiments

    CSIR Research Space (South Africa)

    Van Schoor, Michael

    2013-10-01

    Full Text Available The performance of ground penetrating radar (GPR) under conditions where the ground coupling of the antenna is potentially compromised is investigated. Of particular interest is the effect of increasing the distance between the antennae...

  5. Space-qualifiable Digital Radar Transceiver Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Radar technology offers a very flexible, powerful tool for applications such as object detection, tracking, and characterization, as well as remote sensing, imaging,...

  6. Lunar topography - Global determination by radar.

    Science.gov (United States)

    Shapiro, I. I.; Zisk, S. H.; Rogers, A. E. E.; Slade, M. A.; Thompson, T. W.

    1972-01-01

    Previous methods used for two-dimensional radar mapping of the moon are contrasted with new techniques that add altitude information to the radar map. Delay-Doppler stereoscopy and delay-Doppler interferometry are shown to provide surface-height variations with higher accuracy and better global fidelity than has been possible previously. Sample results are presented for altitude contours on the moon as obtained with the Haystack and Westford radar systems of the Massachusetts Institute of Technology. An appendix describes the mathematical principles of delay-Doppler interferometry in determining the position of an arbitrary reflecting region of the lunar surface from measurements of the time delay, Doppler shift, and fringe phase of radar echoes from that region.

  7. Greenland Radar Ice Sheet Thickness Measurements

    Data.gov (United States)

    National Aeronautics and Space Administration — Two 150-MHz coherent radar depth sounders were developed and flown over the Greenland ice sheet to obtain ice thickness measurements in support of PARCA...

  8. Improved Spectrum Analysis Noise Radar Systems.

    Science.gov (United States)

    and evaluated. A new spectrum analysis system designed to detect moving targets is presented. Comparison is made of the detection capabilities of all four noise radar systems in the presence of extraneous noise. (Author)

  9. The Southern Argentine Agile Meteor Radar (SAAMER)

    Science.gov (United States)

    Janches, Diego

    2014-11-01

    The Southern Argentina Agile Meteor Radar (SAAMER) is a new generation system deployed in Rio Grande, Tierra del Fuego, Argentina (53 S) in May 2008. SAAMER transmits 10 times more power than regular meteor radars, and uses a newly developed transmitting array, which focuses power upward instead of the traditional single-antenna-all-sky configuration. The system is configured such that the transmitter array can also be utilized as a receiver. The new design greatly increases the sensitivity of the radar enabling the detection of large number of particles at low zenith angles. The more concentrated transmitted power enables additional meteor studies besides those typical of these systems based on the detection of specular reflections, such as routine detections of head echoes and non-specular trails, previously only possible with High Power and Large Aperture radars. In August 2010, SAAMER was upgraded to a system capable to determine meteoroid orbital parameters. This was achieved by adding two remote receiving stations approximately 10 km away from the main site in near perpendicular directions. The upgrade significantly expands the science that is achieved with this new radar enabling us to study the orbital properties of the interplanetary dust environment. Because of the unique geographical location, SAAMER allows for additional inter-hemispheric comparison with measurements from Canadian Meteor Orbit Radar, which is geographically conjugate. Initial surveys show, for example, that SAAMER observes a very strong contribution of the South Toroidal Sporadic meteor source, of which limited observational data is available. In addition, SAAMER offers similar unique capabilities for meteor showers and streams studies given the range of ecliptic latitudes that the system enables detailed study of showers at high southern latitudes (e.g July Phoenicids or Puppids complex). Finally, SAAMER is ideal for the deployment of complementary instrumentation in both, permanent

  10. Architecture for a 1-GHz Digital RADAR

    Science.gov (United States)

    Mallik, Udayan

    2011-01-01

    An architecture for a Direct RF-digitization Type Digital Mode RADAR was developed at GSFC in 2008. Two variations of a basic architecture were developed for use on RADAR imaging missions using aircraft and spacecraft. Both systems can operate with a pulse repetition rate up to 10 MHz with 8 received RF samples per pulse repetition interval, or at up to 19 kHz with 4K received RF samples per pulse repetition interval. The first design describes a computer architecture for a Continuous Mode RADAR transceiver with a real-time signal processing and display architecture. The architecture can operate at a high pulse repetition rate without interruption for an infinite amount of time. The second design describes a smaller and less costly burst mode RADAR that can transceive high pulse repetition rate RF signals without interruption for up to 37 seconds. The burst-mode RADAR was designed to operate on an off-line signal processing paradigm. The temporal distribution of RF samples acquired and reported to the RADAR processor remains uniform and free of distortion in both proposed architectures. The majority of the RADAR's electronics is implemented in digital CMOS (complementary metal oxide semiconductor), and analog circuits are restricted to signal amplification operations and analog to digital conversion. An implementation of the proposed systems will create a 1-GHz, Direct RF-digitization Type, L-Band Digital RADAR--the highest band achievable for Nyquist Rate, Direct RF-digitization Systems that do not implement an electronic IF downsample stage (after the receiver signal amplification stage), using commercially available off-the-shelf integrated circuits.

  11. Integration and Validation of Avian Radars (IVAR)

    Science.gov (United States)

    2011-07-01

    elected to locate the Ra serve as the destination for streaming, storing, and redistributing data applications, including the Radar Fusion Engine (RFE...from a study location documented targets being tracked throughout a full, 360° field-of-view. Methods We elected to use the SEA AR-1 radar located...which are less than 10 m from the cart, are there to warn pedestrians of the obstruction on the sidewalk . 267 268 Figure 6-126. eBirdRad

  12. Polarization Diversity for HF Ground Wave Radar

    Institute of Scientific and Technical Information of China (English)

    QIAO Xiaolin; JIN Ming

    2001-01-01

    A new method of single sample polar-ization filtering is proposed.The algorithm is fast andsuitable for the polarization processing of stationaryor nonstationary polarized disturbed signals with oneor more independent sources of disturbance.An HFground wave polarimetric radar with the ability of ra-dio disturbance suppression is then introduced.Somenumerical results demonstrate the effectiveness of sin-gle sample polarization filtering method for groundwave polarimetric radar.

  13. Knowledge Based Systems and Metacognition in Radar

    Science.gov (United States)

    Capraro, Gerard T.; Wicks, Michael C.

    An airborne ground looking radar sensor's performance may be enhanced by selecting algorithms adaptively as the environment changes. A short description of an airborne intelligent radar system (AIRS) is presented with a description of the knowledge based filter and detection portions. A second level of artificial intelligence (AI) processing is presented that monitors, tests, and learns how to improve and control the first level. This approach is based upon metacognition, a way forward for developing knowledge based systems.

  14. Wideband Antennas for Modern Radar Systems

    OpenAIRE

    Ren, Yu-Jiun; Lai, Chieh-Ping

    2010-01-01

    In this chapter, the basics of the antenna and phased array are reviewed and different wideband antennas for modern radar systems are presented. The concepts of the radome and frequency selective surface are also reviewed. The main contents include important parameters of the antenna, and theory and design consideration of the array antenna. Various wideband antennas are introduced and their performances are demonstrated, including: (1) for the phased array radar, the slotted waveguide array ...

  15. Social Radar Workflows, Dashboards, and Environments

    Science.gov (United States)

    2012-01-01

    shows a mockup of such an interface. Figure 3: Social Radar Interface Mock-Up [21] A major lesson learned is that each data source needs to be...for Social Radar is the Ozone Widget Framework (Ozone). This is a lightweight framework that wraps web applications and exposes them to the analyst...as small applications or widgets inside of a web browser. Additionally, Ozone allows the widgets to communicate with one another via provided

  16. Radar Waveform Design in Active Communications Channel

    OpenAIRE

    Ric A. Romero; Shepherd, Kevin D.

    2013-01-01

    In this paper, we investigate spectrally adaptive radar transmit waveform design and its effects on an active communication system. We specifically look at waveform design for point targets. The transmit waveform is optimized by accounting for the modulation spectrum of the communication system while trying to efficiently use the remaining spectrum. With the use of spectrally-matched radar waveform, we show that the SER detection performance of the communication system ...

  17. Radar Baseret Styringspotentiale for Vejle Spildevand

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ellerbæk; Rasmussen, Michael R.

    Denne undersøgelse er initieret af Vejle Spildevands A/S som har bedt Krüger AS om at undersøge styringspotentialet i Vejle by på baggrund af Vejles LAWR radar. Aalborg Universitet har derfor fået til opgave at sammenligne LAWR radaren med både regnmålere og DMI’s Virring radar i 3 udvalgte...... er baseret på 8 SVK-regnmålerne i og omkring Vejle og er desuden sammenlignet med regn estimater fra DMI’s metrologiske C-bånds radar, der er placeret nær Virring ca. 45 km nord-øst for Vejle. De to radarer er i undersøgelsen kalibreres/justeres efter tre forskellige metoder. Det er vigtigt...... at pointere, at datagrundlaget for såvel kalibrering og validering er det samme for de to radarer. Der er således i undersøgelsen kun anvendt data hvor begge radarer har fungeret, således at radarenes kvalitet er evalueret under eksakt samme meteorologiske forhold og med de samme regnmålerdata. Følgende tre...

  18. Airborne Radar Interferometric Repeat-Pass Processing

    Science.gov (United States)

    Hensley, Scott; Michel, Thierry R.; Jones, Cathleen E.; Muellerschoen, Ronald J.; Chapman, Bruce D.; Fore, Alexander; Simard, Marc; Zebker, Howard A.

    2011-01-01

    Earth science research often requires crustal deformation measurements at a variety of time scales, from seconds to decades. Although satellites have been used for repeat-track interferometric (RTI) synthetic-aperture-radar (SAR) mapping for close to 20 years, RTI is much more difficult to implement from an airborne platform owing to the irregular trajectory of the aircraft compared with microwave imaging radar wavelengths. Two basic requirements for robust airborne repeat-pass radar interferometry include the ability to fly the platform to a desired trajectory within a narrow tube and the ability to have the radar beam pointed in a desired direction to a fraction of a beam width. Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is equipped with a precision auto pilot developed by NASA Dryden that allows the platform, a Gulfstream III, to nominally fly within a 5 m diameter tube and with an electronically scanned antenna to position the radar beam to a fraction of a beam width based on INU (inertial navigation unit) attitude angle measurements.

  19. Weather radar rainfall data in urban hydrology

    Science.gov (United States)

    Thorndahl, Søren; Einfalt, Thomas; Willems, Patrick; Ellerbæk Nielsen, Jesper; ten Veldhuis, Marie-Claire; Arnbjerg-Nielsen, Karsten; Rasmussen, Michael R.; Molnar, Peter

    2017-03-01

    Application of weather radar data in urban hydrological applications has evolved significantly during the past decade as an alternative to traditional rainfall observations with rain gauges. Advances in radar hardware, data processing, numerical models, and emerging fields within urban hydrology necessitate an updated review of the state of the art in such radar rainfall data and applications. Three key areas with significant advances over the past decade have been identified: (1) temporal and spatial resolution of rainfall data required for different types of hydrological applications, (2) rainfall estimation, radar data adjustment and data quality, and (3) nowcasting of radar rainfall and real-time applications. Based on these three fields of research, the paper provides recommendations based on an updated overview of shortcomings, gains, and novel developments in relation to urban hydrological applications. The paper also reviews how the focus in urban hydrology research has shifted over the last decade to fields such as climate change impacts, resilience of urban areas to hydrological extremes, and online prediction/warning systems. It is discussed how radar rainfall data can add value to the aforementioned emerging fields in current and future applications, but also to the analysis of integrated water systems.

  20. Raindrop size distribution and radar reflectivity-rain rate relationships for radar hydrology

    NARCIS (Netherlands)

    Uijlenhoet, R.

    2001-01-01

    The conversion of the radar reflectivity factor Z (mm6m-3) to rain rate R (mm h-1) is a crucial step in the hydrological application of weather radar measurements. It has been common practice for over 50 years now to take for this conversion a simple power law relationship between Z and R. It is the

  1. Radar principles for the nonspecialist, 3rd edition

    CERN Document Server

    Toomay, John

    2004-01-01

    Radar Principles for the Non-specialist, Third Edition continues its popular tradition: to distill the very complex technology of radar into its fundamentals, tying them to the laws of nature on one end and to the most modern and complex systems on the other. It starts with electromagnetic propagation, describes a radar of the utmost simplicity, and derives the radar range equation from that simple radar. Once the range equation is available, the book attacks the meaning of each term in it, moving through antennas, detection and tracking, radar cross-section, waveforms andsignal proces

  2. Radar activities of the DFVLR Institute for Radio Frequency Technology

    Science.gov (United States)

    Keydel, W.

    1983-01-01

    Aerospace research and the respective applications microwave tasks with respect to remote sensing, position finding and communication are discussed. The radar activities are directed at point targets, area targets and volume targets; they center around signature research for earth and ocean remote sensing, target recognition, reconnaissance and camouflage and imaging and area observation radar techniques (SAR and SLAR). The radar activities cover a frequency range from 1 GHz up to 94 GHz. The radar program is oriented to four possible application levels: ground, air, shuttle orbits and satellite orbits. Ground based studies and measurements, airborne scatterometers and imaging radars, a space shuttle radar, the MRSE, and follow on experiments are considered.

  3. Sea clutter scattering, the K distribution and radar performance

    CERN Document Server

    Ward, Keith; Watts, Simon

    2013-01-01

    Sea Clutter: Scattering, the K Distribution and Radar Performance, 2nd Edition gives an authoritative account of our current understanding of radar sea clutter. Topics covered include the characteristics of radar sea clutter, modelling radar scattering by the ocean surface, statistical models of sea clutter, the simulation of clutter and other random processes, detection of small targets in sea clutter, imaging ocean surface features, radar detection performance calculations, CFAR detection, and the specification and measurement of radar performance. The calculation of the performance of pract

  4. Sense and avoid radar for micro/nano robots

    Science.gov (United States)

    Molchanov, Pavlo A.; Asmolova, Olha

    2014-10-01

    Revolutionary new fly eye radar sensor technologies based on an array of directional antennas is eliminating the need for a mechanical scanning antenna or complicated phase processor. Proposed sense and avoid radar based on fly eye radar technology can be very small, provides continuous surveillance of entire sky (360 degree by azimuth and elevation) and can be applied for separate or swarm of micro/nano UAS or UGS. Monopulse technology increases bearing accuracy several folds and radar can be multi-functional, multi-frequency. Fly eye micro-radars are inexpensive, can be expendable. Prototype of sense and avoid radar with two directional antennas has been designed and bench tested.

  5. Radar activities of the DFVLR Institute for Radio Frequency Technology

    Science.gov (United States)

    Keydel, W.

    1983-01-01

    Aerospace research and the respective applications microwave tasks with respect to remote sensing, position finding and communication are discussed. The radar activities are directed at point targets, area targets and volume targets; they center around signature research for earth and ocean remote sensing, target recognition, reconnaissance and camouflage and imaging and area observation radar techniques (SAR and SLAR). The radar activities cover a frequency range from 1 GHz up to 94 GHz. The radar program is oriented to four possible application levels: ground, air, shuttle orbits and satellite orbits. Ground based studies and measurements, airborne scatterometers and imaging radars, a space shuttle radar, the MRSE, and follow on experiments are considered.

  6. Techniques for Radar Imaging Based on MUSIC Algorithm

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    At first, the radar target scattering centers model and MUSIC algorithm are analyzed in this paper. How to efficiently set the parameters of the MUSIC algorithms is given by a great deal of simulated radar data in experiments. After that, according to measured data from two kinds of plane targets on fully polarized and high range resolution radar system, the author mainly investigated particular utilization of MUSIC algorithm in radar imaging. And two-dimensional radar images are generated for two targets measured in compact range. In the end, a conclusion is drew about the relation of radar target scattering properties and imaging results.

  7. Observation and theory of the radar aurora

    Energy Technology Data Exchange (ETDEWEB)

    Sahr, J.D.

    1990-01-01

    Plasma density irregularities occurring near the Aurora Borealis cause scattering of HF, VHF, and UHF radio waves. Analysis of the resulting radar signal provides great detail about the spatial and temporal characteristics of these auroral E region irregularities. Observations are presented of the radar aurora from recent campaigns in northern Sweden. After reviewing the basic theory and observations of auroral electrojet irregularities, a simple nonlinear fluid theory of electrojet ion-acoustic waves is introduced, and reduced to a form of the three-wave interaction equations. This theory provides a simple mechanism for excitation of linearly stable waves at large aspect and flow angles, as well as a prediction of the power spectra that a coherent scatter radar should observe. In addition, this theory may be able to account for type 3 waves without resorting to ion gyro modes, such as the electrostatic ion-cyclotron wave. During the course of the research a simple new radar transmitting mode and signal processing algorithm was generated which very simply solves a frequency aliasing problem that often occurs in CUPRI auroral radar studies. Several new radar data analysis routines were developed, including the principally cross-beam image and scatter plots of the second versus first moments of the power spectrum of the irregularities. Analysis of vertical interferometer data shows that type 3 waves originate at ordinary electrojet altitudes, not in the upper E region, from which it is concluded that the electrostatic ion-cyclotron mode does not generate type 3 waves. The measured height of type 3 waves and other spectral analyses provide support for the pure ion-acoustic theory of type 3 waves. Suggestions are offered for hardware improvements to the CUPRI radar, new experiments to test new and existing theories.

  8. Federal Weather Radar Stations in the United States as of September 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent Next-Generation Radar (NEXRAD) and Terminal Doppler Weather Radar (TDWR) weather radar stations within the US. The NEXRAD radar stations are...

  9. An RF tag communication system model for noise radar

    Science.gov (United States)

    Pan, Qihe; Narayanan, Ram M.

    2008-04-01

    RF (radio-frequency) tags have drawn increasing research interest because of their great potential uses in many radio frequency identification applications. They can also be configured to work with radar as a communication channel by receiving radar acquisition signals, suitably coding these, and retransmitting them back to the radar. This paper proposes a system model for the communication between a noise radar and multiple RF tags. The radar interrogates the RF tags in a region of interest by sending ultrawideband noise signals. Upon receiving the radar's signal, all the tags within the radar's range wake up, and respond to the radar with simple messages. The RF tag filters the radar signal to a unique spectral band, which represents its identification information, and different RF tags occupy different non-overlapping bands of the spectrum of the radar signal. Tag messages are modulated onto the waveform through taps of weighted delays. The radar decodes the RF tag identifications and corresponding messages by cross-correlating the RF tag returned signals with the replica of the radar transmitted signal. Calculations and simulation results both show that the proposed system is capable of communicating simple messages between RF tags and radar.

  10. Ground penetrating radar for asparagus detection

    Science.gov (United States)

    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.

  11. Urban Flood Warning Systems using Radar Technologies

    Science.gov (United States)

    Fang, N.; Bedient, P. B.

    2013-12-01

    There have been an increasing number of urban areas that rely on weather radars to provide accurate precipitation information for flood warning purposes. As non-structural tools, radar-based flood warning systems can provide accurate and timely warnings to the public and private entities in urban areas that are prone to flash floods. The wider spatial and temporal coverage from radar increases flood warning lead-time when compared to rain and stream gages alone. The Third Generation Rice and Texas Medical Center (TMC) Flood Alert System (FAS3) has been delivering warning information with 2 to 3 hours of lead time and a R2 value of 93% to facility personnel in a readily understood format for more than 50 events in the past 15 years. The current FAS utilizes NEXRAD Level II radar rainfall data coupled with a real-time hydrologic model (RTHEC-1) to deliver warning information. The system has a user-friendly dashboard to provide rainfall maps, Google Maps based inundation maps, hydrologic predictions, and real-time monitoring at the bayou. This paper will evaluate its reliable performance during the recent events occurring in 2012 and 2013 and the development of a similar radar-based flood warning system for the City of Sugar Land, Texas. Having a significant role in the communication of flood information, FAS marks an important step towards the establishment of an operational and reliable flood warning system for flood-prone urban areas.

  12. Cognitive nonlinear radar test-bed

    Science.gov (United States)

    Hedden, Abigail S.; Wikner, David A.; Martone, Anthony; McNamara, David

    2013-05-01

    Providing situational awareness to the warfighter requires radar, communications, and other electronic systems that operate in increasingly cluttered and dynamic electromagnetic environments. There is a growing need for cognitive RF systems that are capable of monitoring, adapting to, and learning from their environments in order to maintain their effectiveness and functionality. Additionally, radar systems are needed that are capable of adapting to an increased number of targets of interest. Cognitive nonlinear radar may offer critical solutions to these growing problems. This work focuses on ongoing efforts at the U.S. Army Research Laboratory (ARL) to develop a cognitive nonlinear radar test-bed. ARL is working toward developing a test-bed that uses spectrum sensing to monitor the RF environment and dynamically change the transmit waveforms to achieve detection of nonlinear targets with high confidence. This work presents the architecture of the test-bed system along with a discussion of its current capabilities and limitations. A brief outlook is presented for the project along with a discussion of a future cognitive nonlinear radar test-bed.

  13. Operational Bright-Band Snow Level Detection Using Doppler Radar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A method to detect the bright-band snow level from radar reflectivity and Doppler vertical velocity data collection with an atmospheric profiling Doppler radar. The...

  14. Stepped-frequency radar sensors theory, analysis and design

    CERN Document Server

    Nguyen, Cam

    2016-01-01

    This book presents the theory, analysis and design of microwave stepped-frequency radar sensors. Stepped-frequency radar sensors are attractive for various sensing applications that require fine resolution. The book consists of five chapters. The first chapter describes the fundamentals of radar sensors including applications followed by a review of ultra-wideband pulsed, frequency-modulated continuous-wave (FMCW), and stepped-frequency radar sensors. The second chapter discusses a general analysis of radar sensors including wave propagation in media and scattering on targets, as well as the radar equation. The third chapter addresses the analysis of stepped-frequency radar sensors including their principles and design parameters. Chapter 4 presents the development of two stepped-frequency radar sensors at microwave and millimeter-wave frequencies based on microwave integrated circuits (MICs), microwave monolithic integrated circuits (MMICs) and printed-circuit antennas, and discusses their signal processing....

  15. Stellwagen Bank National Marine Sanctuary - Synthetic Aperture Radar (SAR) Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This geodatabase contains Synthetic Aperture Radar images (SAR), which consist of a fine resolution (12.5-50m), two-dimensional radar backscatter map of the...

  16. Detection of small, slow ground targets using Synthetic Aperture Radar

    Science.gov (United States)

    Chen, Curtis; Chapin, Elaine; Rosen, Paul

    2005-01-01

    Synthetic aperture radar (SAR) along-track interferometry (ATI) is a technique for sensing Earth-surface motion. The technique involves interferometrically combining data from two radar images acquired from phase centers separated along the platform flight track.

  17. Ships as salient objects in synthetic aperture radar imaginary

    CSIR Research Space (South Africa)

    Schwegmann, Colin P

    2016-07-01

    Full Text Available The widespread access to Synthetic Aperture Radar data has created a need for more precise ship extraction, specifically in low-to-medium resolution imagery. While Synthetic Aperture Radar pixel resolution is improving for a large swaths...

  18. NOAA Next Generation Radar (NEXRAD) Level III Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of Level III weather radar products collected from Next-Generation Radar (NEXRAD) stations located in the contiguous United States, Alaska,...

  19. NOAA Next Generation Radar (NEXRAD) Level II Base Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of Level II weather radar data collected from Next-Generation Radar (NEXRAD) stations located in the contiguous United States, Alaska, Hawaii,...

  20. Ocean wave imaging mechanism by imaging radar

    Institute of Scientific and Technical Information of China (English)

    何宜军

    2000-01-01

    Analytical representations of the high frequency spectra of ocean wave and its variation due to the variation of ocean surface current are derived from the wave-number spectrum balance equation. The ocean surface imaging formulation of real aperture radar (RAR) is given using electromagnetic wave backscattering theory of ocean surface and the modulations of ocean surface winds, currents and their variations to RAR are described. A general representation of the phase modulation induced by the ocean surface motion is derived according to standard synthetic aperture radar (SAR) imaging theory. The detectability of ocean current and sea bottom topography by imaging radar is discussed. The results constitute the theoretical basis for detecting ocean wave fields, ocean surface winds, ocean surface current fields, sea bottom topography, internal wave and so on.

  1. Updating river basin models with radar altimetry

    DEFF Research Database (Denmark)

    Michailovsky, Claire Irene B.

    response of a catchment to meteorological forcing. While river discharge cannot be directly measured from space, radar altimetry (RA) can measure water level variations in rivers at the locations where the satellite ground track and river network intersect called virtual stations or VS. In this PhD study...... been between 10 and 35 days for altimetry missions until now. The location of the VS is also not necessarily the point at which measurements are needed. On the other hand, one of the main strengths of the dataset is its availability in near-real time. These characteristics make radar altimetry ideally...... suited for use in data assimilation frameworks which combine the information content from models and current observations to produce improved forecasts and reduce prediction uncertainty. The focus of the second and third papers of this thesis was therefore the use of radar altimetry as update data...

  2. Array Processing for Radar: Achievements and Challenges

    Directory of Open Access Journals (Sweden)

    Ulrich Nickel

    2013-01-01

    Full Text Available Array processing for radar is well established in the literature, but only few of these algorithms have been implemented in real systems. The reason may be that the impact of these algorithms on the overall system must be well understood. For a successful implementation of array processing methods exploiting the full potential, the desired radar task has to be considered and all processing necessary for this task has to be eventually adapted. In this tutorial paper, we point out several viewpoints which are relevant in this context: the restrictions and the potential provided by different array configurations, the predictability of the transmission function of the array, the constraints for adaptive beamforming, the inclusion of monopulse, detection and tracking into the adaptive beamforming concept, and the assessment of superresolution methods with respect to their application in a radar system. The problems and achieved results are illustrated by examples from previous publications.

  3. Smoothing Motion Estimates for Radar Motion Compensation.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    Simple motion models for complex motion environments are often not adequate for keeping radar data coherent. Eve n perfect motion samples appli ed to imperfect models may lead to interim calculations e xhibiting errors that lead to degraded processing results. Herein we discuss a specific i ssue involving calculating motion for groups of pulses, with measurements only available at pulse-group boundaries. - 4 - Acknowledgements This report was funded by General A tomics Aeronautical Systems, Inc. (GA-ASI) Mission Systems under Cooperative Re search and Development Agre ement (CRADA) SC08/01749 between Sandia National Laboratories and GA-ASI. General Atomics Aeronautical Systems, Inc. (GA-ASI), an affilia te of privately-held General Atomics, is a leading manufacturer of Remotely Piloted Aircraft (RPA) systems, radars, and electro-optic and rel ated mission systems, includin g the Predator(r)/Gray Eagle(r)-series and Lynx(r) Multi-mode Radar.

  4. MU radar measurements of orbital debris

    Science.gov (United States)

    Sato, Toru; Kayama, Hidetoshi; Furusawa, Akira; Kimura, Iwane

    1990-04-01

    Distributions of orbital debris versus height and scattering cross section are determined from a series of observations made with a high-power VHF Doppler radar (MU radar) of Japan. An automated data processing algorithm has been developed to discriminate echoes of orbiting objects from those of undesired signals such as meteor trail echoes or lightning atmospherics. Although the results are preliminary, they showed good agreement with those from NORAD tracking radar observations using a much higher frequency. It is found that the collision frequency of a Space Station of 1 km x 1 km size at an altitude of 500 km with orbiting debris is expected to be as high as once per two years.

  5. Digital Receiver for Laser Imaging Radar

    Institute of Scientific and Technical Information of China (English)

    WANG Wei Ran; SUN Bing

    2004-01-01

    With the extension of the application domains for laser imaging radar,it is necessary to find a new technical way to obtain high technical performance and adaptive ability.In this paper,A new concept of digital receiver of laser imaging radar system is presented.This digital receiver is defined as a time varying parameter receiver which possesses large dynamics region and time domain filter.The receiver's mode,component structure as well as every function of its processing are described.The results and laboratorial data show the feasibility of digital reception.Also,it can exploit the inherent nature of laser imaging radar to obtain high probability of detection.

  6. Comments on airborne ISR radar utilization

    Science.gov (United States)

    Doerry, A. W.

    2016-05-01

    A sensor/payload operator for modern multi-sensor multi-mode Intelligence, Surveillance, and Reconnaissance (ISR) platforms is often confronted with a plethora of options in sensors and sensor modes. This often leads an over-worked operator to down-select to favorite sensors and modes; for example a justifiably favorite Full Motion Video (FMV) sensor at the expense of radar modes, even if radar modes can offer unique and advantageous information. At best, sensors might be used in a serial monogamous fashion with some cross-cueing. The challenge is then to increase the utilization of the radar modes in a manner attractive to the sensor/payload operator. We propose that this is best accomplished by combining sensor modes and displays into `super-modes'.

  7. Magellan: radar performance and data products.

    Science.gov (United States)

    Pettengill, G H; Ford, P G; Johnson, W T; Raney, R K; Soderblom, L A

    1991-04-12

    The Magellan Venus orbiter carries only one scientific instrument: a 12.6-centimeter wavelength radar system shared among three data-taking modes. The synthetic-aperture mode images radar echoes from the Venus surface at a resolution of between 120 and 300 meters, depending on spacecraft altitude. In the altimetric mode, relative height measurement accuracies may approach 5 meters, depending on the terrain's roughness, although orbital uncertainties place a floor of about 50 meters on the absolute uncertainty. In areas of extremely rough topography, accuracy is limited by the inherent line-of-sight radar resolution of about 88 meters. The maximum elevation observed to date, corresponding to a planetary radius of 6062 kilometers, lies within Maxwell Mons. When used as a thermal emission radiometer, the system can determine surface emissivities to an absolute accuracy of about 0.02. Mosaicked and archival digital data products will be released in compact disk (CDROM) format.

  8. Analytic radar micro-Doppler signatures classification

    Science.gov (United States)

    Oh, Beom-Seok; Gu, Zhaoning; Wang, Guan; Toh, Kar-Ann; Lin, Zhiping

    2017-06-01

    Due to its capability of capturing the kinematic properties of a target object, radar micro-Doppler signatures (m-DS) play an important role in radar target classification. This is particularly evident from the remarkable number of research papers published every year on m-DS for various applications. However, most of these works rely on the support vector machine (SVM) for target classification. It is well known that training an SVM is computationally expensive due to its nature of search to locate the supporting vectors. In this paper, the classifier learning problem is addressed by a total error rate (TER) minimization where an analytic solution is available. This largely reduces the search time in the learning phase. The analytically obtained TER solution is globally optimal with respect to the classification total error count rate. Moreover, our empirical results show that TER outperforms SVM in terms of classification accuracy and computational efficiency on a five-category radar classification problem.

  9. Plasma-based radar cross section reduction

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents a comprehensive review of plasma-based stealth, covering the basics, methods, parametric analysis, and challenges towards the realization of the idea. The concealment of aircraft from radar sources, or stealth, is achieved through shaping, radar absorbing coatings, engineered materials, or plasma, etc. Plasma-based stealth is a radar cross section (RCS) reduction technique associated with the reflection and absorption of incident electromagnetic (EM) waves by the plasma layer surrounding the structure. A plasma cloud covering the aircraft may give rise to other signatures such as thermal, acoustic, infrared, or visual. Thus it is a matter of concern that the RCS reduction by plasma enhances its detectability due to other signatures. This needs a careful approach towards the plasma generation and its EM wave interaction. The book starts with the basics of EM wave interactions with plasma, briefly discuss the methods used to analyze the propagation characteristics of plasma, and its generatio...

  10. Automotive radar - investigation of mutual interference mechanisms

    Science.gov (United States)

    Goppelt, M.; Blöcher, H.-L.; Menzel, W.

    2010-09-01

    In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-performance, low-cost 79 GHz radar sensors based on Silicon-Germanium (SiGe) Monolithic Microwave Integrated Circuits (MMICs). This paper will present some generic interference scenarios and report on the current status of the analysis of interference mechanisms.

  11. Magellan: Radar performance and data products

    Science.gov (United States)

    Pettengill, G.H.; Ford, P.G.; Johnson, W.T.K.; Raney, R.K.; Soderblom, L.A.

    1991-01-01

    The Magellan Venus orbiter carries only one scientific instrument: a 12.6-centimeter-wavelength radar system shared among three data-taking modes. The syntheticaperture mode images radar echoes from the Venus surface at a resolution of between 120 and 300 meters, depending on spacecraft altitude. In the altimetric mode, relative height measurement accuracies may approach 5 meters, depending on the terrain's roughness, although orbital uncertainties place a floor of about 50 meters on the absolute uncertainty. In areas of extremely rough topography, accuracy is limited by the inherent line-of-sight radar resolution of about 88 meters. The maximum elevation observed to date, corresponding to a planetary radius of 6062 kilometers, lies within Maxwell Mons. When used as a thermal emission radiometer, the system can determine surface emissivities to an absolute accuracy of about 0.02. Mosaicked and archival digital data products will be released in compact disk (CDROM) format.

  12. Classification of Target Buried in the Underground by Radar Polarimetry

    OpenAIRE

    Moriyama, Toshifumi; Nakamura, Masafumi; Yamaguchi, Yoshio; Yamada, Hiroyoshi; Boerner, Wolfgang-M.

    1999-01-01

    This paper discusses the classification of targets buried in the underground by radar polarimetry. The subsurface radar is used for the detection of objects buried beneath the ground surface, such as gas pipes, cables and cavities, or in archeological exploration operation. In addition to target echo, the subsurface radar receives various other echoes, because the underground is inhomogeneous medium. Therefore, the subsurface radar needs to distinguish these echoes. In order to enhance the di...

  13. A Short Range, High Accuracy Radar Ranging System,

    Science.gov (United States)

    1984-12-01

    radar cross section of a triangular trihedral reflector can be calculated using a= 4ni (0.289 L) 2 2 (5) r, where L, is the length of the...imaximum radar cross section of 16.1 square meters. Alignment of the axis of the corner reflector was done visually: since triangular corner reflectors ...As the aircraft flies its motion causes the radar cross section of each of the many scatterers to fluctuate. If the radar

  14. THE SYSTEM SIMULATION OF THREE-DIMENSIONAL RADAR

    Institute of Scientific and Technical Information of China (English)

    Zhang Wei; Xiang Jingcheng; Wang Xuegang

    2004-01-01

    To provide a test platform for Electronic Warfare (EW) system, it is needed to simulate the radar received Intermediate Frequency (IF) signals and radar system functions.This letter gives a description of a radar system simulation software developed for frequencyphase scanning three-dimensional (3-D) radar. Experimental results prove that the software could be used for system evaluation and for training purposes as an attractive alternative to real EW system.

  15. IF signals simulation of three-dimensional radar

    Institute of Scientific and Technical Information of China (English)

    Zhang Wei; Wang Xuegang; Zhu Zhaoda

    2008-01-01

    Based on the analysis of the principles of frequency-phase scanning 3-D (three-dimensional) radar and the scattering mechanism of 3-D radar, the target and clutter IF (intermediate frequency) signals model of frequencyphase scanning 3-D radar is presented. The IF signals model of different channels of 3-D radar is presented in one simple formula in which complex waveform effects are considered. The simulation results obtained during tests are also provided in the end.

  16. Bibliography, Background and Overview of UWB radar sensor

    OpenAIRE

    2014-01-01

    Due to the lack of studies in the literature that address the issue of UWB radar sensors, and also because of the great importance of this technology, which is gaining heavily in new application areas, such as the process industry and automotive engineering. A brief summary of the biography of UWB radar sensors have been treated and presented in this article, specifying the difference between pulsed radar sensors regarding CW radar sensor, and two subcategories SFCW FMCW, and highlight the be...

  17. Bibliography, Background and Overview of UWB radar sensor

    OpenAIRE

    2014-01-01

    Due to the lack of studies in the literature that address the issue of UWB radar sensors, and also because of the great importance of this technology, which is gaining heavily in new application areas, such as the process industry and automotive engineering. A brief summary of the biography of UWB radar sensors have been treated and presented in this article, specifying the difference between pulsed radar sensors regarding CW radar sensor, and two subcategories SFCW FMCW, and high...

  18. Comparison of Image Processing Techniques using Random Noise Radar

    Science.gov (United States)

    2014-03-27

    pseudo - random noise . The noise waveforms employed by the radar systems 9 are generally white and Gaussian, that is, the waveform’s power...2010. [5] Hardin, Joshua A. “Information Encoding on a Pseudo Random Noise Radar Waveform”, 2013. [6] Jackson, Julie A. “EENG 668/714 Advanced Radar ...COMPARISON OF IMAGE PROCESSING TECHNIQUES USING RANDOM NOISE RADAR THESIS Jesse Robert B. Cruz, Capt, USAF AFIT-ENG-14-M-22 DEPARTMENT OF THE

  19. Space Radar Image of Central Sumatra, Indonesia

    Science.gov (United States)

    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.

  20. Space Radar Image of Central Sumatra, Indonesia

    Science.gov (United States)

    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.

  1. Block floating point for radar data

    DEFF Research Database (Denmark)

    Christensen, Erik Lintz

    1999-01-01

    Integer, floating point, and block floating point (BFP) data formats are analyzed and compared in order to establish the mathematical tools for selection of an optimal format which fulfils the demands of high resolution radar (SAR) data to large dynamic range and adequate S/N. The analysis takes...... quantization noise and saturation distortion into account and concludes that it is preferred to use small blocks and a (new) modified BFP format applying fractional exponents. Data from the EMISAR radar system are applied to illustrate the merits of the different schemes....

  2. FMCW Radar Jamming Techniques and Analysis

    Science.gov (United States)

    2013-09-01

    Hz (2.19) The beat frequency for the 1st and 2nd section is then f 𔃻b = 2R!F ’ cto " 2V # (2.20) and f 𔃼b = 2R!F ’ cto + 2V " (2.21) with...both beat frequencies calculated, the target range can be computed as 16 R = cto 4!F ’ ( f 𔃻b+ f 𔃼b ) m (2.22) and the target’s range rate is...Australia, 2004, pp. 167–172. [9] Lab-Volt (Quebec) Ltd., Principles of Radar Systems Student Manual . Telecommunications Radar, 2006. [10] O. C

  3. Micropower radar systems for law enforcement technology

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, S.G.; Mast, J.; Brase, J. [Lawrence Livermore National Lab., CA (United States)] [and others

    1994-11-15

    LLNL researchers have pioneered a unique compact low-power and inexpensive radar technology (microradar) that has enormous potential in various industries. Some licenses are currently in place for motion sensors and stud finders. The ultra-wideband characteristics of the microradar (4 to 10 GHz) make it difficult to detect, yet provide potential range resolution of 1 cm at ranges of greater than 20 meters. Real and synthetic apertures arrays of radar elements can address imaging applications behind walls at those distances. Personnel detection applications are currently being tested.

  4. A new approach to lightweight radar altimeters

    Science.gov (United States)

    Levanon, N.; Stremler, F. G.; Suomi, V. E.

    1974-01-01

    Test results and key principles are given for a radar altimeter designed for meteorological balloons. The instrument, which weighs 160 g and consumes 0.7 W, will fill a gap in meteorological sensing using balloons - an area where pressure altitude was formerly the prevailing reference. The instrument is basically a delay-lock radar utilizing a superregenerative RF stage. Long-term absolute accuracy of plus or minus 10 m and short-term stability of better than 2 m rms were measured at altitudes of 20 km.

  5. Soil-penetrating synthetic aperture radar

    Energy Technology Data Exchange (ETDEWEB)

    Boverie, B.; Brock, B.C.; Doerry, A.W.

    1994-12-01

    This report summarizes the results for the first year of a two year Laboratory Directed Research and Development (LDRD) effort. This effort included a system study, preliminary data acquisition, and preliminary algorithm development. The system study determined the optimum frequency and bandwidth, surveyed soil parameters and targets, and defined radar cross section in lossy media. The data acquisition imaged buried objects with a rail-SAR. Algorithm development included a radar echo model, three-dimensional processing, sidelobe optimization, phase history data interpolation, and clutter estimation/cancellation.

  6. Ice measurements by Geosat radar altimetry

    Science.gov (United States)

    Zwally, H. Jay; Bindschadler, Robert A.; Major, Judy A.; Brenner, Anita C.

    1987-01-01

    Radar altimetry for ice-covered ocean and land is more complex and variable than open ocean radar altimetry; attention is presently given to Geosat ice-sheet topography for the Greenland and Antarctic ice sheets between 72 deg N and 72 deg S which owes its excellent accuracy to the well separated spacing of the orbital tracks and an 18-month geodetic mission duration. A surface elevation map of southern Greenland, produced from 110 days of retracked Geosat data, is presented in color-coded three-dimensional perspective. Comparisons are made between Seasat and Geosat data for ice mass elevations in Greenland.

  7. Through-the-wall radar imaging

    CERN Document Server

    Amin, Moeness G

    2011-01-01

    Wall Attenuation and Dispersion, A. Hussein Muqaibel, M.A. Alsunaidi, Nuruddeen M. Iya, and A. Safaai-JaziAntenna Elements, Arrays, and Systems for Through-the-Wall Radar Imaging, A. Hoorfar and A. FathyBeamforming for Through-the-Wall Radar Imaging, G. Alli and D. DiFilippoImage and Localization of Behind-the-Wall Targets Using Collocated and Distributed Apertures, Y.D. Zhang and A. HuntConventional and Emerging Waveforms for Detection and Imaging of Targets behind Walls, F. Ahmad and R.M. NarayananInverse Scattering Approaches in Through-the-Wall Imaging, K. Sarabandi, M. Thiel, M. Dehmollai

  8. Space radar image of New York City

    Science.gov (United States)

    1995-01-01

    This radar image of the New York city metropolitan area. The island of Manhattan appears in the center of the image. The green-colored rectangle on Manhattan is Central Park. 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 10, 1994. North is toward the upper right. The area shown is 75.0 kilometers by 48.8 kilometers (46.5 miles by 30.2 miles). The image is centered at 40.7 degrees north latitude and 73.8 degrees west longitude. In general, light blue areas correspond to dense urban development, green areas to moderately vegetated zones and black areas to bodies of water. The Hudson River is the black strip that runs from the left edge to the upper right corner of the image. It separates New Jersey, in the upper left of the image, from New York. The Atlantic Ocean is at the bottom of the image where two barrier islands along the southern shore of Long Island are also visible. John F. Kennedy International Airport is visible above these islands. Long Island Sound, separating Long Island from Connecticut, is the dark area right of the center of the image. Many bridges are visible in the image, including the Verrazano Narrows, George Washington and Brooklyn bridges. The radar illumination is from the left of the image; this causes some urban zones to appear red because the streets are at a perpendicular angle to the radar pulse. 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). Radar images like this one could be used as a tool for city planners and resource managers to map and monitor land use patterns. The radar imaging systems can clearly detect the variety of landscapes in the area, as well as the density of urban

  9. Space Radar Image of Star City, Russia

    Science.gov (United States)

    1994-01-01

    This radar image shows the Star City cosmonaut training center, east of Moscow, Russia. Four American astronauts are training here for future long-duration flights aboard the Russian Mir space station. These joint flights are giving NASA and the Russian Space Agency experience necessary for the construction of the international Alpha space station, beginning in late 1997. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR), on its 62nd orbit on October 3, 1994. This Star City image is centered at 55.55 degrees north latitude and 38.0 degrees east longitude. The area shown is approximately 32 kilometers by 49 kilometers (20 miles by 30 miles). North is to the top in this image. The radar illumination is from the top of the image. The image was produced using three channels of SIR-C radar data: red indicates L-band (23 cm wavelength, horizontally transmitted and received); green indicates L-band (horizontally transmitted and vertically received); blue indicates C-band (6 cm wavelength, horizontally transmitted and vertically received). In general, dark pink areas are agricultural; pink and light blue areas are urban communities; black areas represent lakes and rivers; dark blue areas are cleared forest; and light green areas are forested. The prominent black runways just right of center are Shchelkovo Airfield, about 4 km long. The textured pale blue-green area east and southeast of Shchelkovo Airfield is forest. Just east of the runways is a thin railroad line running southeast; the Star City compound lies just east of the small bend in the rail line. Star City contains the living quarters and training facilities for Russian cosmonauts and their families. Moscow's inner loop road is visible at the lower left edge of the image. The Kremlin is just off the left edge, on the banks of the meandering Moskva River. The Klyazma River snakes to the southeast from the reservoir in the upper left (shown in bright red

  10. Synchro Controller of Radar on FPGA

    Institute of Scientific and Technical Information of China (English)

    JiangTie-zhen; ShiZhen-hua; WuShi-cai

    2003-01-01

    This paper mainly represents the realization of synchro controller based on the programmable logic devices FPGA by request of HF ground wave radar synchro controller under the instance of making the best of the virtues of FPGA.This design introduces the data communication between PC and synchro controller by I2C Bus, which can carry the synchronous signals' parameters to RAM of synchro controller,then according to the theory that the result of comparing counter value with signals' parameters is the needed wave,we produce all waves HF ground wave radar needs, moreover all waves are produced timesharing in order to save resources.

  11. Synchro Controller of Radar on FPGA

    Institute of Scientific and Technical Information of China (English)

    Jiang Tie-zhen; Shi Zhen-huat; Wu Shi-cai

    2003-01-01

    This paper mainly represents the realization of synchro controller based on the programmable logic devices FPGA by request of HF ground wave radar synchro controller under the instance of making the best of the virtues of FPGA.This design introduces the data communication between PC and synchro controller by I2C Bus, which can carry the syn-chronous signals' parameters to RAM of synchro controller,then according to the theory that the result of comparing counter value with signals' parameters is the needed wave,we produce all waves HF ground wave radar needs, moreover all waves are produced time-sharing in order to save re-sources.

  12. Goldstone Solar System Radar Waveform Generator

    Science.gov (United States)

    Quirk, Kevin J.; Patawaran, Ferze D.; Nguyen, Danh H.; Nguyen, Huy

    2012-01-01

    Due to distances and relative motions among the transmitter, target object, and receiver, the time-base between any transmitted and received signal will undergo distortion. Pre-distortion of the transmitted signal to compensate for this time-base distortion allows reception of an undistorted signal. In most radar applications, an arbitrary waveform generator (AWG) would be used to store the pre-calculated waveform and then play back this waveform during transmission. The Goldstone Solar System Radar (GSSR), however, has transmission durations that exceed the available memory storage of such a device. A waveform generator capable of real-time pre-distortion of a radar waveform to a given time-base distortion function is needed. To pre-distort the transmitted signal, both the baseband radar waveform and the RF carrier must be modified. In the GSSR, this occurs at the up-conversion mixing stage to an intermediate frequency (IF). A programmable oscillator (PO) is used to generate the IF along with a time-varying phase component that matches the time-base distortion of the RF carrier. This serves as the IF input to the waveform generator where it is mixed with a baseband radar waveform whose time-base has been distorted to match the given time-base distortion function producing the modulated IF output. An error control feedback loop is used to precisely control the time-base distortion of the baseband waveform, allowing its real-time generation. The waveform generator produces IF modulated radar waveforms whose time-base has been pre-distorted to match a given arbitrary function. The following waveforms are supported: continuous wave (CW), frequency hopped (FH), binary phase code (BPC), and linear frequency modulation (LFM). The waveform generator takes as input an IF with a time varying phase component that matches the time-base distortion of the carrier. The waveform generator supports interconnection with deep-space network (DSN) timing and frequency standards, and

  13. Multi-antenna synthetic aperture radar

    CERN Document Server

    Wang, Wen-Qin

    2013-01-01

    Synthetic aperture radar (SAR) is a well-known remote sensing technique, but conventional single-antenna SAR is inherently limited by the minimum antenna area constraint. Although there are still technical issues to overcome, multi-antenna SAR offers many benefits, from improved system gain to increased degrees-of-freedom and system flexibility. Multi-Antenna Synthetic Aperture Radar explores the potential and challenges of using multi-antenna SAR in microwave remote sensing applications. These applications include high-resolution imaging, wide-swath remote sensing, ground moving target indica

  14. Radar fall detection using principal component analysis

    Science.gov (United States)

    Jokanovic, Branka; Amin, Moeness; Ahmad, Fauzia; Boashash, Boualem

    2016-05-01

    Falls are a major cause of fatal and nonfatal injuries in people aged 65 years and older. Radar has the potential to become one of the leading technologies for fall detection, thereby enabling the elderly to live independently. Existing techniques for fall detection using radar are based on manual feature extraction and require significant parameter tuning in order to provide successful detections. In this paper, we employ principal component analysis for fall detection, wherein eigen images of observed motions are employed for classification. Using real data, we demonstrate that the PCA based technique provides performance improvement over the conventional feature extraction methods.

  15. External calibration technique of millimeter-wave cloud radar

    Science.gov (United States)

    Wen, Tao; Zhao, Zeng-Liang; Yao, Zhi-Gang; Han, Zhi-Gang; Guo, Lin-Da

    2016-10-01

    The millimeter-wave cloud radar can provide a large number of fine and reliable information for the inversion of cloud macro and micro parameters. A key link of using the millimeter-wave cloud radar to detect the cloud is that the radar must be calibrated. Due to the precision components and severe environment of millimeter-wave cloud radar, subtle changes may take place in the operation process of cloud radar, unless the cloud radar is calibrated regularly. Although the calibration system inside the cloud radar can track and monitor the main working parameters and correct the detection results, it fails to consider the characteristics of the antenna and the mutual influence among different components of cloud radar. Therefore, the external calibration for cloud radar system is very important. Combined with the actual situation of cloud radar under domestic onboard platform, this paper builds a complete external calibration technique process of cloud radar based on the calm sea, providing the theoretical support for the external calibration experiments of the airborne and even satellite-borne millimeter-wave cloud radar developed by our country.

  16. Vertical Pointing Weather Radar for Built-up Urban Areas

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Thorndahl, Søren; Schaarup-Jensen, Kjeld

    2008-01-01

      A cost effective vertical pointing X-band weather radar (VPR) has been tested for measurement of precipitation in urban areas. Stationary tests indicate that the VPR performs well compared to horizontal weather radars, such as the local area weather radars (LAWR). The test illustrated...

  17. Radar Observations of Main-Belt M-class Asteroids

    NARCIS (Netherlands)

    Shepard, Michael K.; Clark, B. E.; Ockert-Bell, M.; Nolan, M. C.; Howell, E. S.; Magri, C.; Giorgini, J. D.; Benner, L. A. M.; Ostro, S. J.; Harris, A. W.; Warner, B. D.; Stephens, R. D.; Mueller, M.

    2009-01-01

    Using the S-band radar at Arecibo Observatory, we have observed 19 Tholen M-class asteroids. The mean radar albedo for all our targets is 0.28 ± 0.13, considerably higher than the mean radar albedo of every other class (Magri et al. 2007, Icarus 186, 126-151). We find approximately one-third (six) o

  18. 49 CFR 176.150 - Radio and radar.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Radio and radar. 176.150 Section 176.150... radar. (a) Except as provided in paragraph (b) of this section, when Class 1 (explosive) materials... as radio and radar transmitters are deenergized by opening the main switches controlling the sources...

  19. Radar micro-doppler signatures processing and applications

    CERN Document Server

    Chen, Victor C; Miceli, William J

    2014-01-01

    Radar Micro-Doppler Signatures: Processing and applications concentrates on the processing and application of radar micro-Doppler signatures in real world situations, providing readers with a good working knowledge on a variety of applications of radar micro-Doppler signatures.

  20. Distributed MIMO Radar for Imaging and High Resolution Target Localization

    Science.gov (United States)

    2012-02-02

    SIMO ) radar systems, based on the BLUE, is provided in [20]. The best achievable accuracy for both configurations is derived. MIMO radar systems with...coherent processing are shown to benefit from higher spatial advantage, compared with SIMO systems. The advantage of the MIMO radar scheme over SIMO

  1. Radar Interferometry : A New Tool for Accurate Height Modelling

    NARCIS (Netherlands)

    Halsema, D. van; Hanssen, R.

    1996-01-01

    Compared to optical sensors the use of radar for Earth observation has only just begun. The first use of radar for this purpose was reported in the sixties. The most important reason to use radar instead of optical sensors is its capability to penetrate through clouds and its day and night imaging

  2. Block diagrams of the radar interface and control unit

    Science.gov (United States)

    Collier, J. W.

    1989-01-01

    The Interface and Control Unit is the heart of the radar module, which occupies one complex channel of the High-Speed Data Acquisition System of the Goldstone Solar System Radar. Block diagrams of the interface unit are presented as an aid to understanding its operation and interconnections to the rest of the radar module.

  3. Radar Observations of Main-Belt M-class Asteroids

    NARCIS (Netherlands)

    Shepard, Michael K.; Clark, B. E.; Ockert-Bell, M.; Nolan, M. C.; Howell, E. S.; Magri, C.; Giorgini, J. D.; Benner, L. A. M.; Ostro, S. J.; Harris, A. W.; Warner, B. D.; Stephens, R. D.; Mueller, M.

    2009-01-01

    Using the S-band radar at Arecibo Observatory, we have observed 19 Tholen M-class asteroids. The mean radar albedo for all our targets is 0.28 ± 0.13, considerably higher than the mean radar albedo of every other class (Magri et al. 2007, Icarus 186, 126-151). We find approximately one-third (six)

  4. Quality assessment of weather radar wind profiles during bird migration

    NARCIS (Netherlands)

    Holleman, I.; van Gasteren, H.; Bouten, W.

    2008-01-01

    Wind profiles from an operational C-band Doppler radar have been combined with data from a bird tracking radar to assess the wind profile quality during bird migration. The weather radar wind profiles (WRWPs) are retrieved using the well-known volume velocity processing (VVP) technique. The X-band

  5. Consideration of radar target glint from ST during OMV rendezvous

    Science.gov (United States)

    McDonald, M. W.; Malone, L. B.; Gleason, E. H.

    1985-09-01

    The nature of radar target glint and the factors upon which it depends when using the Hubble Space Telescope as a radar target is discussed. An analysis of the glint problem using a 35 MHz or 94 MHz radar on the orbital maneuvering vehicle is explored. A strategy for overcoming glint is suggested.

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

    Science.gov (United States)

    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

  7. Extracting radar micro-Doppler signatures of helicopter rotating rotor blades using K-band radars

    Science.gov (United States)

    Chen, Rachel; Liu, Baokun

    2014-06-01

    Helicopter identification has been an attractive topic. In this paper, we applied radar micro-Doppler signatures to identify helicopter. For identifying the type of a helicopter, besides its shape and size, the number of blades, the length of the blade, and the rotation rate of the rotor are important features, which can be estimated from radar micro-Doppler signatures of the helicopter's rotating rotor blades. In our study, K-band CW/FMCW radars are used for collecting returned signals from helicopters. By analyzing radar micro-Doppler signatures, we can estimate the number of blades, the length of the blade, the angular rotation rate of the rotating blade, and other necessary parameters for identifying the type of a helicopter.

  8. Optimal frequency range for medical radar measurements of human heartbeats using body-contact radar.

    Science.gov (United States)

    Brovoll, Sverre; Aardal, Øyvind; Paichard, Yoann; Berger, Tor; Lande, Tor Sverre; Hamran, Svein-Erik

    2013-01-01

    In this paper the optimal frequency range for heartbeat measurements using body-contact radar is experimentally evaluated. A Body-contact radar senses electromagnetic waves that have penetrated the human body, but the range of frequencies that can be used are limited by the electric properties of the human tissue. The optimal frequency range is an important property needed for the design of body-contact radar systems for heartbeat measurements. In this study heartbeats are measured using three different antennas at discrete frequencies from 0.1 - 10 GHz, and the strength of the received heartbeat signal is calculated. To characterize the antennas, when in contact with the body, two port S-parameters(†) are measured for the antennas using a pork rib as a phantom for the human body. The results shows that frequencies up to 2.5 GHz can be used for heartbeat measurements with body-contact radar.

  9. Using TRMM and GPM precipitation radar for calibration of weather radars in the Philippines

    Science.gov (United States)

    Crisologo, Irene; Bookhagen, Bodo; Smith, Taylor; Heistermann, Maik

    2016-04-01

    Torrential and sustained rainfall from tropical cyclones, monsoons, and thunderstorms frequently impact the Philippines. In order to predict, assess, and measure storm impact, it is imperative to have a reliable and accurate monitoring system in place. In 2011, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) established a weather radar network of ten radar devices, eight of which are single-polarization S-band radars and two dual-polarization C-band radars. Because of a low-density hydrometeorological monitoring networks in the Philippines, calibration of weather radars becomes a challenging, but important task. In this study, we explore the potential of scrutinizing the calibration of ground radars by using the observations from the Tropical Rainfall Measuring Mission (TRMM). For this purpose, we compare different TRMM level 1 and 2 orbital products from overpasses over the Philippines, and compare these products to reflectivities observed by the Philippine ground radars. Differences in spatial resolution are addressed by computing adequate zonal statistics of the local radar bins located within the corresponding TRMM cell in space and time. The wradlib package (Heistermann et al. 2013; Heistermann et al. 2015) is used to process the data from the Subic S-band single-polarization weather radar. These data will be analyzed in conjunction with TRMM data for June to August 2012, three months of the wet season. This period includes the enhanced monsoon of 2012, locally called Habagat 2012, which brought sustained intense rainfall and massive floods in several parts of the country including the most populated city of Metro Manila. References Heistermann, M., Jacobi, S., Pfaff, T. (2013): Technical Note: An open source library for processing weather radar data (wradlib). Hydrol. Earth Syst. Sci., 17, 863-871, doi: 10.5194/hess-17-863-2013. Heistermann, M., S. Collis, M. J. Dixon, S. Giangrande, J. J. Helmus, B. Kelley, J

  10. Challenges in X-band Weather Radar Data Calibration

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Rasmussen, Michael R.

    2009-01-01

    Application of weather radar data in urban hydrology is evolving and radar data is now applied for both modelling, analysis and real time control purposes. In these contexts, it is all-important that the radar data well calibrated and adjusted in order to obtain valid quantitative precipitation...... estimates. This paper compares two calibration procedures for a small marine X-band radar by comparing radar data with rain gauge data. Validation shows a very good consensus with regards to precipitation volumes, but more diverse results on peak rain intensities....

  11. Marine X-band Weather Radar Data Calibration

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2012-01-01

    Application of weather radar data in urban hydrology is evolving and radar data is now applied for both modelling, analysis, and real time control purposes. In these contexts, it is allimportant that the radar data is well calibrated and adjusted in order to obtain valid quantitative precipitation...... estimates. This paper presents some of the challenges in small marine X-band radar calibration by comparing three calibration procedures for assessing the relationship between radar and rain gauge data. Validation shows similar results for precipitation volumes but more diverse results on peak rain...

  12. Influences of weather phenomena on automotive laser radar systems

    Science.gov (United States)

    Rasshofer, R. H.; Spies, M.; Spies, H.

    2011-07-01

    Laser radar (lidar) sensors provide outstanding angular resolution along with highly accurate range measurements and thus they were proposed as a part of a high performance perception system for advanced driver assistant functions. Based on optical signal transmission and reception, laser radar systems are influenced by weather phenomena. This work provides an overview on the different physical principles responsible for laser radar signal disturbance and theoretical investigations for estimation of their influence. Finally, the transmission models are applied for signal generation in a newly developed laser radar target simulator providing - to our knowledge - worldwide first HIL test capability for automotive laser radar systems.

  13. Digital signal processing techniques and applications in radar image processing

    CERN Document Server

    Wang, Bu-Chin

    2008-01-01

    A self-contained approach to DSP techniques and applications in radar imagingThe processing of radar images, in general, consists of three major fields: Digital Signal Processing (DSP); antenna and radar operation; and algorithms used to process the radar images. This book brings together material from these different areas to allow readers to gain a thorough understanding of how radar images are processed.The book is divided into three main parts and covers:* DSP principles and signal characteristics in both analog and digital domains, advanced signal sampling, and

  14. Application Research on Space Laser Communication in Bistatic Radar System

    Institute of Scientific and Technical Information of China (English)

    李晓萍; 韩绍坤; 郝小宁

    2003-01-01

    There exist three synchronizing problems in the bistatic radar system that some signals of the radar receiver must be synchronized with those of the radar transmitter. Several methods realizing data transmission, which are used to complete the synchronization existing in the bistatic radar system, are described. Then a new idea is brought forward that employs space laser communication in the bistatic radar system to realize its data transmission. The theoretic analysis of the idea's usability and its merits are discussed in details. Finally the latest development of space laser communication is introduced, and the utility of the idea is pointed out further.

  15. Marine X-band Weather Radar Data Calibration

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2012-01-01

    Application of weather radar data in urban hydrology is evolving and radar data is now applied for both modelling, analysis, and real time control purposes. In these contexts, it is allimportant that the radar data is well calibrated and adjusted in order to obtain valid quantitative precipitation...... estimates. This paper presents some of the challenges in small marine X-band radar calibration by comparing three calibration procedures for assessing the relationship between radar and rain gauge data. Validation shows similar results for precipitation volumes but more diverse results on peak rain...

  16. Tabu search for target-radar assignment

    DEFF Research Database (Denmark)

    Hindsberger, Magnus; Vidal, Rene Victor Valqui

    2000-01-01

    In the paper the problem of assigning air-defense illumination radars to enemy targets is presented. A tabu search metaheuristic solution is described and the results achieved are compared to those of other heuristic approaches, implementation and experimental aspects are discussed. It is argued...

  17. Motion measurement for synthetic aperture radar

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    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.

  18. Radar cross section measurements using terahertz waves

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

    2010-01-01

    Radar cross sections at terahertz frequencies are measured on scale models of aircrafts. A time domain broadband THz system generates freely propagating THz pulses measured with sub-picosecond time resolution. The THz radiation is generated using fs laser pulses by optical rectification in a lith......Radar cross sections at terahertz frequencies are measured on scale models of aircrafts. A time domain broadband THz system generates freely propagating THz pulses measured with sub-picosecond time resolution. The THz radiation is generated using fs laser pulses by optical rectification...... in a lithium niobate crystal with application of the tilted wave front method, resulting in high electric field THz pulses with a broad band spectrum from 100 GHz up to 4 THz. The corresponding wave lengths are two orders of magnitude smaller than normal radars and we therefore use scale models of size 5-10 cm...... in order to measure realistic radar cross sections. RCS polar and azimuthal angle plots of F-16 and F-35 are presented....

  19. Multiple hypothesis clustering in radar plot extraction

    NARCIS (Netherlands)

    Huizing, A.G.; Theil, A.; Dorp, Ph. van; Ligthart, L.P.

    1995-01-01

    False plots and plots with inaccurate range and Doppler estimates may severely degrade the performance of tracking algorithms in radar systems. This paper describes how a multiple hypothesis clustering technique can be applied to mitigate the problems involved in plot extraction. The measures of

  20. Aircraft height estimation using 2-D radar

    CSIR Research Space (South Africa)

    Hakl, H

    2010-01-01

    Full Text Available A method to infer height information from an aircraft tracked with a single 2-D search radar is presented. The method assumes level flight in the target aircraft and a good estimate of the speed of the aircraft. The method yields good results...