Method for separating precipitation echoes and sea surface backscattering in echo signals of scatterometer

Abstract

The invention provides a method for separating precipitation echoes and sea surface backscattering in the echo signals of a scatterometer. Pulse compression is carried out on the received echo signals to output compressed pulse signals, minor lobe restraining is carried out on the compressed pulse signals through a frequency domain windowing algorithm, the coupling of distance minor lobes existing in precipitation echo signals and sea surface echo signals is eliminated, the time domain aliasing of precipitation and the sea surface is effectively separated, Doppler frequency correction and energy decrement compensation are carried out in a frequency domain, effective precipitation and sea surface backscattering coefficients can be extracted and synchronously inverted from complex air-sea boundary mixed echo signals, the mutual influence can be eliminated or compensated, and the precipitation echoes and sea surface backscattering can be effectively separated.

Description

technical field [0001] The invention relates to the technical field of marine-atmospheric environment monitoring, in particular to a method for separating precipitation echo and sea surface backscatter in echo signals of a scatterometer. Background technique [0002] Currently, a scatterometer is a radar specially designed to measure the normalized backscatter cross section with high precision. The spaceborne microwave scatterometer is currently the most important remote sensor to obtain the global sea surface wind field, because the sea surface roughness is the main factor affecting the backscatter, and there is a certain correspondence between the sea surface roughness and the sea surface wind speed. Therefore, the scatterometer can invert the sea surface wind field by measuring the backscatter coefficient of the sea surface modulated by the wind field. However, the electromagnetic waves of the scatterometer are seriously affected by precipitation, which is mainly reflect...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem of inaccurate precipitation information and sea surface wind field information obtained by inversion due to the coupling of precipitation echo and sea surface backscatter in the scatterometer echo signal, the present invention provides a scatterometer echo The separation method of precipitation echo and sea surface backscatter in wave signal, using this separation method can effectively separate the time domain aliasing of precipitation and sea surface, and perform Doppler frequency estimation and energy attenuation compensation in the frequency domain, which can be obtained from complex Extract and synchronously invert the effective precipitation and sea surface backscatter coefficients from the sea-air boundary mixed echo signal, eliminate or compensate for the mutual influence, and realize the effective separation of precipitation echo and sea surface backscatter, so as to improve the Wind field / precipitation retrieval accuracy under weather

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