Quantitative study of tropical rain cells from ERS SAR imagery

Abstract

This paper investigates the backscatter signatures of an ERS-2 SAR image of tropical rain cells. The particular type of rain cell studied is a squall line. By comparing with simultaneously acquired ground-based weather radar data, possible attenuation effects from the rain column in the atmosphere are investigated. The rainfall rate is estimated from the attenuation signature in the SAR imagery. Comparison between the estimated rainfall rate and weather radar rainfall rate shows consistency. Wind speed associated with the squall line is also estimated based on the CMOD4 scatterometry model. The estimated wind speed pattern appears to be in agreement with the observed squall line structure. Possible errors in the wind estimation due to effects of rain are suggested. Further study is required to validate these initial results.