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The wind fields retrieved by scatterometers from GMF (Geographical Modelling Function) would be invalidated under rainy conditions, due to scattering and attenuation effects of rain drops. The scatterometer (HSCAT) and the scanning microwave radiometer (RM) onboard HY-2A can give observations over sea surface at the same time. In this paper, firstly, data of HSCAT and RM onboard HY-2A observing rainy...
The sea state bias (SSB) has become the dominant source of error in satellite altimetry. The operational SSB correction models are two-dimensional (2-D) nonparametric models based on the wind speed (U) and the significant wave height (SWH) that can be directly measured by the altimeters. This paper estimates the sea state bias of HY-2A radar altimeter using a three-dimensional (3-D) nonparametric...
This paper reviews several wind quality-sensitive parameters derived from HY-2A scatterometer data, such as the wind-inversion residual (or Maximum Likelihood Estimator, MLE) and its spatially averaged value, and the singularity exponent (SE) derived from an image processing technique, called singularity analysis. Their sensitivity to data quality is evaluated using the collocated European Centre...
Linear frequency modulated (LFM) continuous wave (CW) synthetic aperture radar (SAR) is promising in airborne earth observation with compact, lightweight, cost-effective and high resolution advantages. For CW imaging radars, however, weak targets may be submerged by sidelobes of strong range interferences including transmitter leakage and nadir signal, especially when the slant range is far. This...
This paper presents a new simulator for spaceborne SAR on-board imaging process on mobile GPUs. The system can generate raw data and perform imaging process in real time. Due to introducing low power GPUs, it has low power consumption, light weight and high computing capability. This simulator has the unique structure, which can guarantee its real-time processing. The experimented results indicate...
In this study, we focus on the investigations of oil slicks observed by TerraSAR-X and TanDEM-X operating over the drilling platforms in Forties oil field, the largest one in the North Sea. Previous researches indicate that oil spills observed by consecutive SAR images represent the same leaks, but in this paper, we presented four cases which suggest completely different situations of oil spill variations...
Ground based interferometric radar (GBIR) is a revolutionary advanced measurement technique for geoscience and engineering geodesy. It is powerful for temporally and spatially dense measurements of highly dynamic target with sub-millimetric accuracy, especially in man-made structures, e.g. buildings, towers, dams and bridges. In this case study, we use a real aperture radar system, the Gamma Portable...
Air or satellite borne radar systems has shown millimeter accuracy in change detection by realizing the phase of the returned signal, which has put the radar system a useful piece of tool in structural monitoring and disaster prevention [1]. However the temporal availability of data is very limited due to long revisiting time. This problem could be solved by using a ground based radar system, which...
Dual-frequency Precipitation Radar (DPR) consists of Ka- and Ku-band radars which operate in scanning mode at low incidence angles. It is installed on the Global Precipitation Measurement (GPM) satellite. Definition of boundary wave number in frameworks of the two-scale model of scattering surface is an important problem for investigation and modelling of radar backscatter from the sea surface. In...
Stepped-Frequency Microwave Radiometer (SFMR) measurements and Precipitation Radar (PR) data on tropical rainfall measuring mission (TRMM) are collocated to acquire the normalized radar cross sections (NRCS) at low incidence angles. At the same time, the whitecap coverages are concluded from averaging previous results. Using the formation of Kudryavtsev et al, the NRCS of whitecap is obtained. The...
The scatterometer onboard the China-France Oceanography Satellite (CFOSAT) will be the first rotating fan-beam scatterometer (RFSCAT) ever flown in space for global ocean vector wind measurement. The status and progress of the scatterometer will be presented, including the mission schedule, payload design and development, validation experiments. The internal calibration strategy, Doppler compensation...
Global Navigation Satellite Systems Reflectometry (GNSSR) is a sort of multi-static radar using navigation signals as signals of opportunity. Due to the large number of transmitting satellites multiple scattering points over the Earth's surface can be simultaneously tracked, which provides wide-swath and improved spatio-temporal sampling over current space-borne radar altimetry missions. The lack...
Dual-Frequency Polarized Scatterometer (DFPSCAT) is a new system utilizing Doppler beam sharpening (DBS) technology for azimuthal resolution enhancement. Considering the DBS technology is inapplicable for the middle areas of the swath, a theoretical framework of deconvolution signal processing is proposed to improve resolution. A deconvolution method of the nonlocally centralized sparse representation...
The Chinese and French Space Agencies are jointly preparing an innovative mission, CFOSAT (China France Oceanography Satellite) devoted to the monitoring of the ocean surface and its related science and applications. This paper gives an overview of the scientific objectives, the mission and instrument characteristics, the expected data products and their performance.
As the launch of radars, such as the Precipitation Radar (PR) on Tropical Rainfall Measuring Mission (TRMM)[1] satellite and the Surface Wave Investigation and Monitoring (SWIM) on China France Oceanography SATellite (CFOSAT)[2], that operate in low incident angles, more and more NRCS data at low incident angle will be obtained. In order to retrieve the sea surface wind speed using low incident angle...
The GNSS rEflectometry, Radio Occultation and Scatterometry onboard the International Space Station (GEROS-ISS) is an innovative experiment for climate research, proposed in 2011 within a call of the European Space Agency (ESA) for installation at the ISS. This international proposal was the only one selected for further studies by ESA out of ∼25 submitted ones. In this work, an updated assessment...
The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite was developed by JAXA and NICT. This paper describes mission objectives, technical performance, resource allocation, ground test results, orbital check out results and orbital operation status of the DPR. The DPR system PFT has completed in February 2012. GPM core spacecraft satellite...
Mass-weighted mean diameter Dm is explicitly estimated in the GPM/DPR algorithms. The spatial and temporal variations of Dm are analyzed by fixing the range of precipitation rates R. Generally, Dm is higher over land than over ocean. In India, the seasonal variation in Dm is shown. Such spatial and temporal variations are clearly seen for heavy precipitation. Compared with the TRMM/PR algorithm, KuPR...
Hydrometeor profile is a critical module in GPM DPR level 2 algorithm. The module has been extensively evaluated since GPM launch. Consistency has been achieved between dual-frequency classification algorithm and TRMM like single frequency classification algorithm. Melting region detection is cross-validated with ground radar and shows satisfactory results. Enhancement of dual-frequency classification...
An approach to check accuracy of Ku- and Ka-band dual-frequency radar techniques for retrieval of rain rate and rain drop size distribution (DSD) is studied by using measured DSD data. The radar retrieval look-up tables introduced are effective not only in inferring rain rate and DSD parameters but also in evaluating overall performance of retrieval algorithms. As an example of the methods used for...
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