Determination of Ocean Wave Propagation Direction Based on Azimuth Scanning Mode

The purpose of this letter is to show that the azimuth scanning mode of a synthetic aperture radar can be applied to deriving ocean wave spectra and determining the wave propagation direction for the first time, which reveals its enormous potential and great future in ocean observation. The improved Doppler beam sharpening imaging algorithm is used to produce a sequence of individual subimages of ocean waves in the same scan region from different aspect angles with a high revisit rate. These subimages have an inherent property that they are formed at different discretely delayed times. Therefore, wave propagation direction can be determined from a pair of wave images in different scans. Several different methods are applied to the real airborne radar wave data, including the methods of scan sum (taking the standard Fourier spectrum of the scan-summed image), spectral sum, spectral phase shift, and cross-correlation function of subimages. The processing results demonstrate the effectiveness of the algorithms.

[1]  Kazuo Ouchi,et al.  Determination of ocean wave propagation direction by split-look processing using JERS-1 SAR data , 1999, IEEE Trans. Geosci. Remote. Sens..

[2]  W. Brown.  Synthetic Aperture Radar , 1967, IEEE Transactions on Aerospace and Electronic Systems.

[3]  L. J. Cutrona,et al.  A Comparison of Techniques for Achieving Fine Azimuth Resolution , 1962, IRE Transactions on Military Electronics.

[4]  Harald Johnsen,et al.  SAR-ocean wave inversion using image cross spectra , 1995, IEEE Trans. Geosci. Remote. Sens..

[5]  D. Ross,et al.  On the detectability of ocean surface waves by real and synthetic aperture radar , 1981 .

[6]  Paris W. Vachon,et al.  Spectral estimation techniques for multilook SAR images of ocean waves , 1992, IEEE Trans. Geosci. Remote. Sens..

[7]  M. Smolarczyk,et al.  First polish SAR trials , 2006 .

[8]  W John,et al.  Backscattering from Capillary Waves with Application to Sea Clutter , 1966 .

[9]  Christoph H. Gierull,et al.  Experimental Verification of SAR-GMTI Improvement Through Antenna Switching , 2010, IEEE Transactions on Geoscience and Remote Sensing.

[10]  Wen Hong,et al.  On the TOPS mode spaceborne SAR , 2010, Science China Information Sciences.

[11]  Yunkai Deng,et al.  A New High Resolution DBS Imaging Algorithm Based on Least Squares Linear Fitting: A New High Resolution DBS Imaging Algorithm Based on Least Squares Linear Fitting , 2011 .

[12]  Werner Alpers,et al.  The effect of orbital motions on synthetic aperture radar imagery of ocean waves , 1979 .

[13]  W. Carrara,et al.  Spotlight synthetic aperture radar : signal processing algorithms , 1995 .

[14]  W. J. Kenneally,et al.  JointSTARS and GMTI: past, present and future , 1999 .

[15]  P. W. Vachon,et al.  Resolution of the ocean wave propagation direction in SAR imagery , 1991, IEEE Trans. Geosci. Remote. Sens..