scholarly journals Annual validation of significant wave heights of ERS-1 synthetic aperture radar wave mode spectra using TOPEX/Poseidon and ERS-1 altimeter data

1999 ◽  
Vol 104 (C6) ◽  
pp. 13345-13357 ◽  
Author(s):  
Eva Bauer ◽  
Patrick Heimbach
Keyword(s):  
Synthetic Aperture Radar ◽  
Wave Mode ◽  
Synthetic Aperture ◽  
Altimeter Data ◽  
Significant Wave ◽  
Wave Heights ◽  
Significant Wave Heights ◽  
Radar Wave ◽  
Aperture Radar

scholarly journals On the retrieval of significant wave heights from spaceborne Synthetic Aperture Radar (ERS-SAR) using the Max-Planck Institut (MPI) algorithm

2005 ◽  
Vol 77 (4) ◽  
pp. 745-755 ◽  
Author(s):  
Nelson Violante-Carvalho
Keyword(s):  
Data Assimilation ◽  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
Wave Spectra ◽  
Max Planck ◽  
Sar Images ◽  
Significant Wave ◽  
Wave Heights ◽  
Significant Wave Heights ◽  
Directional Wave

Synthetic Aperture Radar (SAR) onboard satellites is the only source of directional wave spectra with continuous and global coverage. Millions of SAR Wave Mode (SWM) imagettes have been acquired since the launch in the early 1990's of the first European Remote Sensing Satellite ERS-1 and its successors ERS-2 and ENVISAT, which has opened up many possibilities specially for wave data assimilation purposes. The main aim of data assimilation is to improve the forecasting introducing available observations into the modeling procedures in order to minimize the differences between model estimates and measurements. However there are limitations in the retrieval of the directional spectrum from SAR images due to nonlinearities in the mapping mechanism. The Max-Planck Institut (MPI) scheme, the first proposed and most widely used algorithm to retrieve directional wave spectra from SAR images, is employed to compare significant wave heights retrieved from ERS-1 SAR against buoy measurements and against the WAM wave model. It is shown that for periods shorter than 12 seconds the WAM model performs better than the MPI, despite the fact that the model is used as first guess to the MPI method, that is the retrieval is deteriorating the first guess. For periods longer than 12 seconds, the part of the spectrum that is directly measured by SAR, the performance of the MPI scheme is at least as good as the WAM model.

scholarly journals Analysis of ERS-1/2 synthetic aperture radar wave mode imagettes

1998 ◽  
Vol 103 (C4) ◽  
pp. 7833-7846 ◽  
Author(s):  
Vincent Kerbaol ◽  
Bertrand Chapron ◽  
Paris W. Vachon
Keyword(s):  
Synthetic Aperture Radar ◽  
Wave Mode ◽  
Synthetic Aperture ◽  
Radar Wave ◽  
Aperture Radar

scholarly journals Capabilities of Chinese Gaofen-3 Synthetic Aperture Radar in Selected Topics for Coastal and Ocean Observations

2018 ◽  
Vol 10 (12) ◽  
pp. 1929 ◽  
Author(s):  
Xiao-Ming Li ◽  
Tianyu Zhang ◽  
Bingqing Huang ◽  
Tong Jia
Keyword(s):  
Synthetic Aperture Radar ◽  
Surface Wind ◽  
Wave Mode ◽  
Sea Surface ◽  
Synthetic Aperture ◽  
Radiometric Calibration ◽  
Sea Surface Wind ◽  
Wind Retrievals ◽  
Sea Surface Wave ◽  
Aperture Radar

Gaofen-3 (GF-3), the first Chinese spaceborne synthetic aperture radar (SAR) in C-band for civil applications, was launched on August 2016. Some studies have examined the use of GF-3 SAR data for ocean and coastal observations, but these studies generally focus on one particular application. As GF-3 has been in operation over two years, it is essential to evaluate its performance in ocean observation, a primary goal of the GF-3 launch. In this paper, we offer an overview demonstrating the capabilities of GF-3 SAR in ocean and coastal observations by presenting several representative cases, i.e., the monitoring of intertidal flats, offshore tidal turbulent wakes and oceanic internal waves, to highlight the GF-3’s full polarimetry, high spatial resolution and wide-swath imaging advantages. Moreover, we also present a detailed analysis of the use of GF-3 quad-polarization data for sea surface wind retrievals and wave mode data for sea surface wave retrievals. The case studies and statistical analysis suggest that GF-3 has good ocean and coastal monitoring capabilities, though further improvements are possible, particularly in radiometric calibration and stable image quality.

Born inversion of surface-scattered SAR (synthetic aperture radar) wave field

1991 ◽  
Vol 69 (10) ◽  
pp. 1256-1260 ◽  
Author(s):  
Wooil M. Moon
Keyword(s):  
Synthetic Aperture Radar ◽  
Wave Field ◽  
Correction Term ◽  
Image Formation ◽  
Scattered Wave ◽  
Synthetic Aperture ◽  
Curvature Correction ◽  
Formation Technique ◽  
Radar Wave ◽  
Aperture Radar

A new approach to synthetic aperture radar (SAR) digital image formation, based on inverse scattering theory, is derived as an alternative to the conventional method of imaging surface-scattered wave fields. The conventional image formation technique for high-resolution SAR data utilized azimuth compression using correlation in the range-Doppler domain. More recent approaches in SAR image formation algorithms exploit downward extrapolation of the wave field in the frequency–wavenumber (f–k) domain to perform not only the azimuth compression but also the range curvature correction at the same time, with improved quality of the final image. In this paper, imaging of the SAR wave field is formulated with the Born inversion approach, which includes a range-curvature-correction term that is valid at all ranges of image formation. This new inversion formula is established to exploit f–k domain computation, from which the complex backscattering coefficient, defined by the ratio of the backscattered wave field to the incident wave field, can be accurately estimated from the observed back-scattered wave field.

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