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22 results on '"S-band radar"'

1. Radar-SR3: A Weather Radar Image Super-Resolution Generation Model Based on SR3.

Author

Shi, Zhanpeng, Geng, Huantong, Wu, Fangli, Geng, Liangchao, and Zhuang, Xiaoran

Subjects
*IMAGE reconstruction algorithms, *RADAR meteorology, *HIGH resolution imaging, *GENERATIVE adversarial networks, *IMAGE reconstruction, *INTERPOLATION algorithms, *RANDOM noise theory
Abstract

To solve the problems of the current deep learning radar extrapolation model consuming many resources and the final prediction result lacking details, a weather radar image super-resolution weather model based on SR3 (super-resolution via image restoration and recognition) for radar images is proposed. This model uses a diffusion model to super-resolve weather radar images to generate high-definition images and optimizes the performance of the U-Net denoising network on the basis of SR3 to further improve image quality. The model receives high-resolution images with Gaussian noise added and performs channel splicing with low-resolution images for conditional generation. The experimental results showed that the introduction of the diffusion model significantly improved the spatial resolution of weather radar images, providing new technical means for applications in related fields; when the amplification factor was 8, Radar-SR3, compared with the image super-resolution model based on the generative adversarial network (SRGAN) and the bicubic interpolation algorithm, the peak signal-to-noise ratio (PSNR) increased by 146% and 52% on average. According to this model, it is possible to train radar extrapolation models with limited computing resources with high-resolution images. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Comparison of Rain Gauge Network and Weather Radar Data: Case Study in Angra dos Reis, Brazil.

Author

Silva, Elton John Robaina da, Alves, Camila Nascimento, Campos, Priscila Celebrini de Oliveira, Oliveira, Raquel Aparecida Abrahão Costa e, Marques, Maria Esther Soares, Amorim, José Carlos Cesar, and Paz, Igor

Subjects
WEATHER radar networks, RADAR meteorology, RAIN gauges, RAINFALL, NATURAL disasters
Abstract

This paper presents a comparison between rain gauge network and weather radar data in Angra dos Reis city, located in the State of Rio de Janeiro (RJ), Brazil. The city has a high incidence of natural disasters, especially associated with heavy rains in densely populated areas. In this work, weather radar data with a spatial resolution of 1 km were obtained from dual-polarimetric S-band radar operated by the Environmental State Institute of Rio de Janeiro (INEA), located in the Guaratiba neighborhood in Rio de Janeiro city, Brazil; the rain gauge measurements were provided by the National Center for Monitoring and Warning of Natural Disasters (CEMADEN), which is composed of a network with 30 rain gauges covering the studied area. The comparison between the two datasets enables the analysis of which radar products better fit the rain gauge network's accumulated rainfall by quantifying the uncertainties in precipitation estimates at radar pixels where rain gauges are located. The results indicated that radar products generated with the help of regression techniques obtained from the relation between radar reflectivities and rain gauge measurements were a better fit, constituting essential information while dealing with efficient regulation for rainfall monitoring and forecasting to minimize the risks associated with extreme events. [ABSTRACT FROM AUTHOR]

Published
2022
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4. Detection of Target and Suppression of Sea and Weather Clutter in Stormy Weather by Weibull/CFAR.

Author

Sayama, Shuji

Subjects
*CLUTTER (Radar), *WEATHER, *WEIBULL distribution, *ELECTRICAL engineers, *DATA distribution, *FALSE alarms
Abstract

In stormy weather due to typhoon approaching the Izu Islands, I have observed sea and weather clutter containing a target (ship) using an S‐band radar with a frequency of 3.05 GHz, a beamwidth of 1.8°, a pulsewidth of 0.5 μs, and a pulse‐repetition frequency of 1600 Hz. To analyze such clutter amplitude statistics, I have used partial Q–Q plot, which is more rigorous fit of the distribution to the data than conventional Q–Q plot. It has been found that the sea and weather clutter amplitudes obey the Weibull distribution with the shape parameters of c = 6.23 for entire data and c = 5.83 to 8.78 for small data within the beamwidth of an antenna. I have applied Weibull/CFAR (constant false alarm rate) circuit configured by modifying cell‐averaging (CA) LOG/CFAR circuit to the observed data. It has been found that ship is detected, and sea and weather clutter is suppressed with improvement of 33.61 dB by Weibull/CFAR. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Published
2021
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5. On the performance of the unscented Kalman filter for floating Doppler wind lidar motion correction in an open-sea scenario

Author

Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. CommSensLab-UPC - Centre Específic de Recerca en Comunicació i Detecció UPC, Salcedo Bosch, Andreu, Rocadenbosch Burillo, Francisco, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. CommSensLab-UPC - Centre Específic de Recerca en Comunicació i Detecció UPC, Salcedo Bosch, Andreu, and Rocadenbosch Burillo, Francisco

Abstract

This work analyzes the influence of open-sea wave motion on the performance of the floating Doppler wind lidar motion-compensation method [1], recently published by the authors. The method is applied to a floating ZephIR 300 LiDAR and compared to a fixed LiDAR as a reference. The motion-correction results are studied as a function of the wave-motion intensity by clustering the IJmuiden experimental campaign into three categories: low, medium, and high motion., This research is part of the project PID2021-126436OB-C21 funded by Ministerio de Ciencia e Investigacion (MCIN)/ Agencia Estatal de Investigacion (AEI)/ 10.13039/501100011033 y FEDER “Una manera de hacer Europa”. The work of A. Salcedo-Bosch was supported under grant 2020 FISDU 00455 funded by Generalitat de Catalunya—AGAUR. The European Commission collaborated under projects H2020 ATMO-ACCESS (GA101008004) and H2020 ACTRIS-IMP (GA-871115)., Peer Reviewed, Postprint (author's final draft)

Published
2023

6. Comparison of Rain Gauge Network and Weather Radar Data: Case Study in Angra dos Reis, Brazil

Author

Elton John Robaina da Silva, Camila Nascimento Alves, Priscila Celebrini de Oliveira Campos, Raquel Aparecida Abrahão Costa e Oliveira, Maria Esther Soares Marques, José Carlos Cesar Amorim, and Igor Paz

Subjects
Geography, Planning and Development, rain gauge network, spatiotemporal variability, S-band radar, extreme events, Aquatic Science, Biochemistry, Water Science and Technology
Abstract

This paper presents a comparison between rain gauge network and weather radar data in Angra dos Reis city, located in the State of Rio de Janeiro (RJ), Brazil. The city has a high incidence of natural disasters, especially associated with heavy rains in densely populated areas. In this work, weather radar data with a spatial resolution of 1 km were obtained from dual-polarimetric S-band radar operated by the Environmental State Institute of Rio de Janeiro (INEA), located in the Guaratiba neighborhood in Rio de Janeiro city, Brazil; the rain gauge measurements were provided by the National Center for Monitoring and Warning of Natural Disasters (CEMADEN), which is composed of a network with 30 rain gauges covering the studied area. The comparison between the two datasets enables the analysis of which radar products better fit the rain gauge network’s accumulated rainfall by quantifying the uncertainties in precipitation estimates at radar pixels where rain gauges are located. The results indicated that radar products generated with the help of regression techniques obtained from the relation between radar reflectivities and rain gauge measurements were a better fit, constituting essential information while dealing with efficient regulation for rainfall monitoring and forecasting to minimize the risks associated with extreme events.

Published
2022
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7. Suppression of sea clutter and detection of small ship observed by an S‐band Radar.

Author

Sayama, Shuji

Subjects
*SHIPS, *RADAR, *WEIBULL distribution, *RADIO technology, *SIMULATION methods & models
Abstract

Abstract: I have observed sea clutter including a target (small ship) using an S‐band radar with a frequency of 3.05 GHz, a beamwidth of 1.8°, a pulsewidth of 0.5 μs, and a pulse‐repetition frequency of 1600 Hz. To investigate the sea clutter amplitude statistics, I introduce the Akaike Information Criterion (AIC). I have found that the sea clutter amplitudes obey the log‐normal distribution with the shape parameter of σ = 0.385 for entire data and the log‐normal,Weibull, and log‐Weibull distributions with the shape parameters of σ = 0.379‐0.505, c = 2.92‐4.81, and c = 12.33‐15.28, respectively, for data within the beam width of an antenna. The number of the smallest AIC (MAIC) of the log‐normal, Weibull, and log‐Weibull distributions to data are 3, 5, and 4, respectively, from 12 range sweep numbers. I have used the Weibull/CFAR (constant false alarm rate) circuit which is modified a Cell‐Averaging (CA) LOG/CFAR circuit. It is found that small ship is detected and sea clutter is suppressed with improvement of 24.83 dB by Weibull/CFAR. [ABSTRACT FROM AUTHOR]

Published
2018
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8. A novel approach for calculating the internal layers of snowpacks using a S-band radar

Author

Pedro Espin and M. Persian

Subjects
Radar, Ground-based techniques, Internal layers, Snow water equivalent, Snow, Ground based radar, Manual techniques, S-band radar, Liquid water content, Internal structure, Multi-layers, Snowpack
Abstract

In the last years, the development of new ground-based techniques for studying the snowpack has tried to fill the gap between satellite and manual techniques. In particular, ground-based radars are considered a very useful technology for their ability to sound relatively deep snowpacks in a non-destructive way. Obtaining the bulk physical parameters of the snowpack (density, liquid water content...) has been successfully done using ground-based radars by several research groups, however, estimating the internal structure of the snowpack remains as a challenge due, mainly, to technological limitations. This work presents a novel quasi-automatic approach to estimate the internal structure of the snowpack, in terms of density and liquid water content (LWC), based in a double receiver S-band radar. The approach is validated with numerical simulations and the very first field results. © 2022 European Microwave Association (EuMA).

Published
2022

9. Numerical solver for vertical air motion estimation

Author

Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció, Salcedo Bosch, Andreu, Domínguez Pla, Paula, Rocadenbosch Burillo, Francisco, Frasier, Stephen J., Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció, Salcedo Bosch, Andreu, Domínguez Pla, Paula, Rocadenbosch Burillo, Francisco, and Frasier, Stephen J.

Abstract

We present preliminary research on a method to estimate Vertical Air Motion (VAM) at a particular height by comparing the measured rain-rate (RR) by a vertically-pointing S-band Frequency-Modulated Continuous-Wave (FMCW) radar with that of a ground-based disdrometer. The method is based on a constrained parametric solver, assuming high correlation between 5-min averaged rain rates measured by the radar and disdrometer. The method is tested over disdrometer and radar observations during the Verification of the ORigins Tornado EXperiment in South East US (VORTEX-SE) project. Finally, the results are partially validated by means of fitting a gamma distribution to the VAM-corrected DSD profiles and studying its parameters., This research is part of the projects PGC2018-094132-B-I00 and MDM2016-0600 (“CommSensLab” Excellence Unit) funded by Ministerio de Ciencia e Investigación (MCIN)/ Agencia Estatal de Investigación (AEI)/10.13039/501100011033/ FEDER “Una manera de hacer Europa”. The work of A. Salcedo-Bosch was supported under grant 2020 FISDU 00455 funded by Generalitat de Catalunya—AGAUR. The European Commission collaborated under projects H2020 ACTRIS-IMP (GA-871115) and H2020 ATMOACCESS (GA-101008004)., Peer Reviewed, Postprint (author's final draft)

Published
2022

10. S-Band Doppler Wave Radar System.

Author

Zezong Chen, Zihan Wang, Xi Chen, Chen Zhao, Fei Xie, and Chao He

Subjects
*RADAR, *RADIO waves, *TRANSFER functions, *THEORY of wave motion, *WAVE analysis
Abstract

In this paper, a novel shore-based S-band microwave Doppler coherent wave radar (Microwave Ocean Remote SEnsor (MORSE)) is designed to improve wave measurements. Marine radars, which operate in the X band, have been widely used for ocean monitoring because of their low cost, small size and flexibility. However, because of the non-coherent measurements and strong absorption of X-band radio waves by rain, these radar systems suffer considerable performance loss in moist weather. Furthermore, frequent calibrations to modify the modulation transfer function are required. To overcome these shortcomings, MORSE, which operates in the S band, was developed by Wuhan University. Because of the coherent measurements of this sensor, it is able to measure the radial velocity of water particles via the Doppler effect. Then the relation between the velocity spectrum and wave height spectrum can be used to obtain the wave height spectra. Finally, wave parameters are estimated from the wave height spectra by the spectrum moment method. Comparisons between MORSE and Waverider MKIII are conducted in this study, and the results, including the non-directional wave height spectra, significant wave height and average wave period, are calculated and displayed. The correlation coefficient of the significant wave height is larger than 0.9, whereas that of the average wave period is approximately 0.4, demonstrating the effectiveness of MORSE for the continuous monitoring of ocean areas with high accuracy. [ABSTRACT FROM AUTHOR]

Published
2017
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11. Legal and Economic Aspects of Naval Blockades: The United States, Great Britain, and Germany in World War II.

Author

Davis, Lance E. and Engerman, Stanley L.

Abstract

INTRODUCTION By World War I, improvements in technology, particularly the innovation of long-range coastal defense guns, mines, and submarines, had all but ruled out “close blockades” of the type that characterized warfare from the English-French continental wars of the eighteenth century through at least the American Civil War. Earlier, most blockades were “close blockades,” that “must be confined to ports and coasts belonging to or occupied by the enemy.” By 1914, however, “close” blockades had been replaced by “distant” ones. The blockading vessels were now almost always positioned further out to sea, with a corresponding potential for more contact with nonbelligerent shipping; however, as long as the blockade can adequately restrict movements into and out of enemy ports, this form of interdiction is considered legally valid. Another important change is that although in the twentieth century most blockades have been enforced by government-owned-and-operated vessels, in the past the blockading vessels have included private ships operating under letters of marque as government approved privateers. Historically, the distinction between private and government blockades raised a number of issues including legal questions of controls over appropriate behavior and domestic questions involving the relative size of peacetime and wartime navies. LESSONS FROM THE PAST: WORLD WAR I Given its precursors and the size of the conflagration, it is not surprising that policies adopted during World War I almost entirely rewrote the rules of naval blockades; and the history of the war itself appeared to confirm that, in the future, the convoy was to become the ultimate weapon against a “distant” blockade. [ABSTRACT FROM AUTHOR]

Published
2006
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12. Suppression of Weather Clutter by Means of Log-Normal/CFAR Circuit Modified from CA LOG/CFAR Circuit.

Author

Sayama, Shuji and Ishii, Seishiro

Subjects
*CLUTTER (Radar), *WEATHER forecasting, *AKAIKE information criterion, *ANTENNAS (Electronics), *WEIBULL distribution
Abstract

SUMMARY We have observed weather clutter including targets (ships) using an S-band radar with a frequency of 3.05 GHz, a beamwidth of 1.8°, and a pulse width of 0.5 μs. To investigate weather clutter amplitude statistics, we introduce the Akaike information criterion (AIC). We have found that the weather clutter amplitudes obey log-normal, Weibull, and log-Weibull distributions with shape parameters of 0.329 to 0.477, 4.40 to 4.55, and 11.93 to 16.44, respectively, for data within the beamwidth of an antenna. We propose the log-normal/CFAR circuit, modified from a cell-averaging (CA) LOG/CFAR circuit. It is found that weather clutter is suppressed with improvement of 51.58 dB by log-normal/CFAR. [ABSTRACT FROM AUTHOR]

Published
2014
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13. Atmospheric Remote Sensing and Adaptive Processing: Boundary-Layer radar observation in the context of U.S. VORTEX project

Author

Villalonga Llauger, Joan, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Rocadenbosch Burillo, Francisco, and Tanamachi, Robin

Subjects
Remote Sensing, Radar, Física [Àrees temàtiques de la UPC], Turbulència atmosfèrica, Anàlisi d'error (Matemàtica), adaptive filtering, atmosphere, Atmospheric turbulence, S-band radar, Error analysis (Mathematics), boundary layer, signal processing
Published
2020

14. Convective boundary-layer height estimation from combined radar and Doppler lidar observations in VORTEX-SE

Author

Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció, Villalonga, Joan, Beveridge, Susan L., Silva, Marcos Paulo Aráujo da, Tanamachi, Robin, Rocadenbosch Burillo, Francisco, Turner, David Dave, Frasier, Stephen J., Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció, Villalonga, Joan, Beveridge, Susan L., Silva, Marcos Paulo Aráujo da, Tanamachi, Robin, Rocadenbosch Burillo, Francisco, Turner, David Dave, and Frasier, Stephen J.

Abstract

The Verification of the Origins of Rotation in Tornadoes Experiment Southeast (VORTEX-SE) provides a wealth of long-duration, high-resolution, vertically pointing observations from active and passive ground-based remote sensing systems enabling characterization of the Atmospheric Boundary Layer (ABL) development over distinct regions that are well known for their relatively high tornado frequency. Application of the Extended Kalman Filter (EKF) to BL height estimation in the convective regime (CBLH) of the diurnal cycle from S-band radar reflectivity observations1 has shown to yield accurate results under simple CBL conditions. In this work, we revisit the radar-EKF technique and investigate its main limitations. For example, during daytime clear-sky conditions such as those prevailing in the BL morning transition, weak turbulence leads to very low reflectivity returns, limiting application of this technique. Additionally, turbulent mixing layers capped with a residual layer, and/or multi-layer scenarios can lead the filter to lose track of the BL signature over time. Doppler Wind Lidar (DWL) observations of the vertical wind velocity variance2 provide complementary CBLH estimates to those of the radar-EKF combination, providing potential to disambiguate more complex convective cases. DWL estimates are, however, strongly influenced by the variance threshold selected. The complementarity of radar and DWL for CBLH estimation is studied in reference to radiosoundings., This work was supported by NOAA grants NA1501R4590232 and NA16OAR4590209, and by the Purdue University Dept. of Earth, Atmospheric, and Planetary Sciences (EAPS). CommSensLab-UPC (Excellence Unit MDM-2016-0600 funded by the Agencia Estatal de Investigación, Spain) collaborated via Spanish Gov.- EU Regional Development Funds, ARS project PGC2018-094132-B-I00 and ACTRIS-PPP project GA-739530. The Spanish National Science Foundation (Ministerio de Ciencia, Innovación y Universidades) funded doctoral grant PRE2018-086054 hold by M.P. Araujo da Silva., Peer Reviewed, Postprint (published version)

Published
2020

15. Atmospheric boundary layer height disambiguation using synergistic remote sensing observations: case examples from VORTEX-SE

Author

Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció, Rocadenbosch Burillo, Francisco, Tanamachi, Robin, Silva, Marcos Paulo Aráujo da, Villalonga, Joan, Frasier, Stephen J., Turner, David Dave, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció, Rocadenbosch Burillo, Francisco, Tanamachi, Robin, Silva, Marcos Paulo Aráujo da, Villalonga, Joan, Frasier, Stephen J., and Turner, David Dave

Abstract

Synergistic remote sensing of the atmosphere, combined with adaptive techniques, offers unprecedented opportunities to characterise the evolution of key atmospheric features such as the Atmospheric Boundary Layer (ABL). Using long-duration, high-resolution, profiling observations from active and passive ground-based remote sensing systems during the Verification of the Origins of Rotation in Tornadoes Experiment{Southeast (VORTEX-SE) 2017 field campaign, an attempt is made to characterise ABL development over distinct regions that are well known for their relatively high tornado frequency. In this study, observing systems include an S-band radar, Vaisala CL-31 ceilometer, Doppler Wind lidar (DWL) and radiometric observations from the Collaborative Lower Atmosphere Mobile Profiling System (CLAMPS). In this work, ABL height (ABLH) tracking over the diurnal cycle, and - up to a point - its disambiguation over selected non-precipitating case examples, are attempted. Different observational sets are used, namely, radar reflectivity observations assimilated into a Kalman filter, DWL profiles of the vertical velocity, and virtual potential temperature profiles, as well as radiosoundings and cloudbase reference information collected during Intensive Observation Periods (IOP) carried out in VORTEX-SE, Alabama during 2017. Limitations and advantages of each system are discussed., This work was supported by NOAA grants NA1501R4590232 and NA16OAR4590209, and by the Purdue University Dept. of Earth, Atmospheric, and Planetary Sciences (EAPS). CommSensLab-UPC (Excellence UnitMDM-2016-0600 funded by the Agencia Estatal de Investigación, Spain) collaborated via Spanish Gov.– EURegional Development Funds, ARS project PGC2018-094132-B-I00 and ACTRIS-PPP project GA-739530. The Spanish National Science Foundation (Ministerio de Ciencia, Innovación y Universidades) funded doctoral grant PRE2018-086054 hold by M.P. Araujo da Silva., Peer Reviewed, Postprint (published version)

Published
2020

17. Amplitude Statistics of Ground Clutter from Town and Hill Observed by an S-Band Radar.

Author

Sayama, Shuji and Ishii, Seishiro

Subjects
*AMPLITUDE estimation, *WEIBULL distribution, *AMPLITUDE modulation
Abstract

We have observed ground clutter from a town and hills using an S-band radar with a frequency of 3.05 0Hz, a beamwidth of 1.8°, and a pulse width of 1.0 μs, located on the campus of the National Defense Academy in Yokosuka City. To investigate such ground clutter amplitude statistics, we introduce a compound distribution and the Akaike Information Criterion (AIC). We have found that the ground clutter amplitude obeys the compound lognormal distribution with shape parameters of σ1 = 0.424, σ2 = 0.232 for the entire data and the compound lognormal and compound log-Weibull distributions with shape parameters of σ1 = 0.217 to 0.429, σ2 = 0.028 to 0.410, and c1 = 9.36 to 11.20 and c2 = 17.00 to 23.81, respectively, for data within the beamwidth of an antenna. The numbers for the minimum AIC (MAIC) of the compound lognormal and log-Weibull distributions are 8 and 4, respectively. [ABSTRACT FROM AUTHOR]

Published
2013
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18. Evaluation of X-Band Polarimetric-Radar Estimates of Drop-Size Distributions From Coincident S-Band Polarimetric Estimates and Measured Raindrop Spectra.

Author

Anagnostou, Marios N., Anagnostou, Emmanouil N., Vulpiani, Gianfranco, Montopoli, Mario, Marzano, Frank S., and Vivekanandan, Jothiram

Subjects
*ELECTRONIC pulse techniques, *DETECTORS, *SPECTRUM analysis, *RADAR research, *REMOTE sensing, *RAINFALL, *RADAR meteorology
Abstract

Recent research has demonstrated the value of polarimetric measurements for the correction of rain-path attenuation at X-band radar frequency and the estimation of rain parameters including drop-size distributions (DSD). The issue this paper is concerned with is to what degree uncertainties in attenuation correction can affect the estimation of DSD. Since attenuation-correction uncertainty enhances with rain path, our hypothesis is that DSD retrieval uncertainty at X-band may deteriorate with range. In this paper, we evaluate the relative accuracy of X-band DSD retrieval against DSD estimates from S-band radar observations and in situ disdrometer spectra. We present comparisons of various techniques for estimating DSD model parameters from attenuation-corrected X-band dual-polarization radar data. Coincident X-band polarimetric-radar (XPOL) and S-band polarimetric-radar dual-polarized radar measurements from the International H2O Project experiment as well as coincident XPOL (MP-X) measurements over disdrometer during a typhoon storm case in Japan are used to assess the accuracy of the different DSD retrieval algorithms applied to X-band radar measurements. [ABSTRACT FROM AUTHOR]

Published
2008
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19. Statistical Comparison of Algorithms.

Author

Kedem, Benjamin, Wolff, David B., and Fokianos, Konstantinos

Subjects
*ALGORITHMS, *ELECTRONIC systems, *ELECTRIC distortion, *RADAR, *PARAMETER estimation, *DIGITAL communications
Abstract

A "reference" algorithm or instrument and its various "distortions" are considered, where the distortions carry some valid information about the reference. The objective is to combine data from the reference and the distortions together in some manner in order to extract information from both the reference, as well as the distortions, and produce improved inference about the true reference algorithm. This is illustrated in terms of in precipitation radars and semiparametric estimation of the reference distribution and the distortion parameters. [ABSTRACT FROM AUTHOR]

Published
2004
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20. Convective boundary-layer height estimation from combined radar and Doppler lidar observations in VORTEX-SE

Author

Joan Villalonga, Marcos Paulo Araujo Da Silva, David D. Turner, Susan L. Beveridge, Robin L. Tanamachi, Stephen J. Frasier, Francesc Rocadenbosch, Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, and Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció

Subjects
Doppler lidar, 010504 meteorology & atmospheric sciences, Planetary boundary layer, 0211 other engineering and technologies, 02 engineering and technology, Optical radar, Boundary layer (Meteorology), Adaptive filtering, Atmospheric boundary layer, Tornados, 01 natural sciences, Convective Boundary Layer, Wind speed, law.invention, symbols.namesake, law, Diurnal cycle, Capa límit (Meteorologia), Radar, Physics::Atmospheric and Oceanic Physics, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Remote sensing, Radar òptic, Tornadoes, Lidar, Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Teledetecció [Àrees temàtiques de la UPC], 13. Climate action, symbols, S-band radar, Tornado, Doppler effect, Estimation, Geology
Abstract

The Verification of the Origins of Rotation in Tornadoes Experiment Southeast (VORTEX-SE) provides a wealth of long-duration, high-resolution, vertically pointing observations from active and passive ground-based remote sensing systems enabling characterization of the Atmospheric Boundary Layer (ABL) development over distinct regions that are well known for their relatively high tornado frequency. Application of the Extended Kalman Filter (EKF) to BL height estimation in the convective regime (CBLH) of the diurnal cycle from S-band radar reflectivity observations1 has shown to yield accurate results under simple CBL conditions. In this work, we revisit the radar-EKF technique and investigate its main limitations. For example, during daytime clear-sky conditions such as those prevailing in the BL morning transition, weak turbulence leads to very low reflectivity returns, limiting application of this technique. Additionally, turbulent mixing layers capped with a residual layer, and/or multi-layer scenarios can lead the filter to lose track of the BL signature over time. Doppler Wind Lidar (DWL) observations of the vertical wind velocity variance2 provide complementary CBLH estimates to those of the radar-EKF combination, providing potential to disambiguate more complex convective cases. DWL estimates are, however, strongly influenced by the variance threshold selected. The complementarity of radar and DWL for CBLH estimation is studied in reference to radiosoundings. This work was supported by NOAA grants NA1501R4590232 and NA16OAR4590209, and by the Purdue University Dept. of Earth, Atmospheric, and Planetary Sciences (EAPS). CommSensLab-UPC (Excellence Unit MDM-2016-0600 funded by the Agencia Estatal de Investigación, Spain) collaborated via Spanish Gov.- EU Regional Development Funds, ARS project PGC2018-094132-B-I00 and ACTRIS-PPP project GA-739530. The Spanish National Science Foundation (Ministerio de Ciencia, Innovación y Universidades) funded doctoral grant PRE2018-086054 hold by M.P. Araujo da Silva.

Published
2020

21. Atmospheric boundary layer height disambiguation using synergistic remote sensing observations: case examples from VORTEX-SE

Author

Marcos Paulo Araujo Da Silva, Francesc Rocadenbosch, Stephen J. Frasier, Robin L. Tanamachi, Joan Villalonga, David D. Turner, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, and Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció

Subjects
Doppler lidar, Teledetecció, 010504 meteorology & atmospheric sciences, Storms, Planetary boundary layer, 0211 other engineering and technologies, 02 engineering and technology, Optical radar, Boundary layer (Meteorology), Adaptive filtering, Atmospheric boundary layer, 01 natural sciences, law.invention, Atmosphere, Diurnal cycle, law, Capa límit (Meteorologia), Radar, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Remote sensing, Profiling (computer programming), Ceilometer, Kalman filter, Radar òptic, Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Teledetecció [Àrees temàtiques de la UPC], 13. Climate action, S-band radar, Environmental science, Tornado, Estimation, Tempestes
Abstract

Synergistic remote sensing of the atmosphere, combined with adaptive techniques, offers unprecedented opportunities to characterise the evolution of key atmospheric features such as the Atmospheric Boundary Layer (ABL). Using long-duration, high-resolution, profiling observations from active and passive ground-based remote sensing systems during the Verification of the Origins of Rotation in Tornadoes Experiment{Southeast (VORTEX-SE) 2017 field campaign, an attempt is made to characterise ABL development over distinct regions that are well known for their relatively high tornado frequency. In this study, observing systems include an S-band radar, Vaisala CL-31 ceilometer, Doppler Wind lidar (DWL) and radiometric observations from the Collaborative Lower Atmosphere Mobile Profiling System (CLAMPS). In this work, ABL height (ABLH) tracking over the diurnal cycle, and - up to a point - its disambiguation over selected non-precipitating case examples, are attempted. Different observational sets are used, namely, radar reflectivity observations assimilated into a Kalman filter, DWL profiles of the vertical velocity, and virtual potential temperature profiles, as well as radiosoundings and cloudbase reference information collected during Intensive Observation Periods (IOP) carried out in VORTEX-SE, Alabama during 2017. Limitations and advantages of each system are discussed. This work was supported by NOAA grants NA1501R4590232 and NA16OAR4590209, and by the Purdue University Dept. of Earth, Atmospheric, and Planetary Sciences (EAPS). CommSensLab-UPC (Excellence UnitMDM-2016-0600 funded by the Agencia Estatal de Investigación, Spain) collaborated via Spanish Gov.– EURegional Development Funds, ARS project PGC2018-094132-B-I00 and ACTRIS-PPP project GA-739530. The Spanish National Science Foundation (Ministerio de Ciencia, Innovación y Universidades) funded doctoral grant PRE2018-086054 hold by M.P. Araujo da Silva.

Published
2020

22. S-Band Doppler Wave Radar System

Author

Chen Zhao, Fei Xie, Zezong Chen, Zihan Wang, Chao He, and Xi Chen

Subjects
010504 meteorology & atmospheric sciences, Acoustics, Science, 0211 other engineering and technologies, X band, wave measuring, MORSE, 02 engineering and technology, 01 natural sciences, law.invention, symbols.namesake, law, Wave height, Radar, Physics::Atmospheric and Oceanic Physics, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Physics, directional wave height spectrum, coherent method, significant wave height, microwave ocean remote sensor, Wave radar, symbols, S-band radar, General Earth and Planetary Sciences, S band, Significant wave height, Doppler effect, Radio wave
Abstract

In this paper, a novel shore-based S-band microwave Doppler coherent wave radar (Microwave Ocean Remote SEnsor (MORSE)) is designed to improve wave measurements. Marine radars, which operate in the X band, have been widely used for ocean monitoring because of their low cost, small size and flexibility. However, because of the non-coherent measurements and strong absorption of X-band radio waves by rain, these radar systems suffer considerable performance loss in moist weather. Furthermore, frequent calibrations to modify the modulation transfer function are required. To overcome these shortcomings, MORSE, which operates in the S band, was developed by Wuhan University. Because of the coherent measurements of this sensor, it is able to measure the radial velocity of water particles via the Doppler effect. Then the relation between the velocity spectrum and wave height spectrum can be used to obtain the wave height spectra. Finally, wave parameters are estimated from the wave height spectra by the spectrum moment method. Comparisons between MORSE and Waverider MKIII are conducted in this study, and the results, including the non-directional wave height spectra, significant wave height and average wave period, are calculated and displayed. The correlation coefficient of the significant wave height is larger than 0.9, whereas that of the average wave period is approximately 0.4, demonstrating the effectiveness of MORSE for the continuous monitoring of ocean areas with high accuracy.

Published
2017

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