Title :
A study of sea surface height retrieval using Doppler measurements from numerically simulated low grazing angle backscatter data
Author :
Chae, Chun-Sik ; Johnson, Joel T.
Author_Institution :
Dept. of Electr. & Comput. Eng., Ohio State Univ., Columbus, OH, USA
Abstract :
A numerical study of the retrieval of sea surface height profiles from low grazing angle Doppler radar measurements is described. Backscattered fields computed using the method-of-moments for one-dimensional ocean-like surface profiles are used to examine properties of Doppler spectra versus range. "Discrete" behaviors observed in the Doppler spectra versus range are found to be related to similar behaviors in orbital velocity statistics obtained directly from the corresponding surface profiles. Differences between Doppler spectra are also observed between VV- and HH-polarizations, with VV-polarization showing smaller Doppler spectral widths in some situations. In order to improve understanding of the accuracies to be expected in surface profile retrievals from Doppler information, estimation errors for the Doppler centroid versus range are studied using a simplified signal model. Comparisons of the results of this signal model with the method-of-moments simulations show that shadowing and multi-path propagation effects cause errors in Doppler centroid estimation beyond those caused by speckle effects alone.
Keywords :
Doppler radar; sea level; 1D ocean-like surface profiles; Doppler centroid estimation; Doppler spectral widths; HH-polarization; VV-polarization; backscattered fields; low grazing angle Doppler radar measurements; low grazing angle backscatter data; low grazing angle radar; method-of-moments simulations; multipath propagation effects; orbital velocity statistics; rough surface scattering; sea surface height retrieval; speckle effects; Computational modeling; Doppler effect; Rough surfaces; Sea surface; Surface impedance; Surface roughness; Surface waves; Doppler radar; low grazing angle radar; rough surface scattering; sea surface scattering;
Conference_Titel :
Geoscience and Remote Sensing Symposium (IGARSS), 2011 IEEE International
Conference_Location :
Vancouver, BC
Print_ISBN :
978-1-4577-1003-2
DOI :
10.1109/IGARSS.2011.6049342