Accession Number : ADA138392

Title :   Measurement of Ocean Surface Winds by Seasat Synthetic Aperture Radar.

Descriptive Note : Topic rept.,

Corporate Author : ENVIRONMENTAL RESEARCH INST OF MICHIGAN ANN ARBOR RADAR DIV

Personal Author(s) : Lyden,J D ; Lyzenga,D R ; Shuchman,R A ; Jones,W L

PDF Url : ADA138392

Report Date : Jul 1983

Pagination or Media Count : 105

Abstract : This report investigates the feasibility of using Seasat Synthetic Aperture Radar (SAR) data for measuring ocean surface winds. An empirical model relating the received power of the L-band SAR to ocean surface wind conditions was evaluated. Results from this investigation indicate that past Seasat SAR wind studies could be biased due to the nature of the measurement techniques employed. In these past studies, densitometer measurements of output imagery were related to wind speed and direction. Because of a shifting of the Doppler spectrum location with latitude due to the earth's rotation and spacecraft attitude change, these measurements are valid only over short azimuthal distances. A theoretical correction was calculated and applied to the Seasat data, resulting in improved correlations with the surface wind speed. Additionally, a simplified measurement technique which did not involve explicit corrections for this Doppler shifting was developed. The results of this study are consistent with those of previous investigations, but yield additional insight into the angular dependence of the SAR backscatter and the accuracy of the technique.

Descriptors :   *Wind, *Synthetic aperture radar, Artificial satellites, Radar signals, L band, Backscattering, Doppler effect, Electromagnetic spectra, Oceans, Surface roughness, Mathematical prediction, Signal processing

Subject Categories : Meteorology
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE