Airborne synthetic aperture radar sea surface wind vector retrieval method

Abstract

The invention discloses a retrieval method which uses the change rule of the uniformization radar section along with incidence angles and the specific corresponding relation between the wind direction and the wind speed to directly confirm a sea surface wind vector according to the linear characteristics of incidence angles in a detecting range of an airborne SAR. The retrieval method specifically comprises the steps of firstly confirming detecting data of the airborne SAR, then controlling image quality and confirming a beginning incidence angle and an end incidence angle, thirdly confirming a row mean value curve of the change of the uniformization radar section along with the incidence angles and building a standard curve base, and then finding a curve with the highest similarity to the row mean value curve for the specific standard curve base to obtain the wind direction and the wind speed. The retrieval method gets rid of relying on auxiliary information, directly uses airborne SAR detecting data to accurately invert the sea surface wind vector and can provide technical support for service application of airborne SAR sea surface wind vector retrieval.

Description

technical field [0001] The invention belongs to the technical field of microwave remote sensing, in particular to an airborne synthetic aperture radar sea surface wind vector inversion method based on the change law of normalized radar cross section with incident angle. Background technique [0002] Airborne Synthetic Aperture Radar (SAR) sea surface wind vector retrieval mainly uses detection data to calculate the wind direction and wind speed at a height of 10m above the sea surface. The CMOD geophysical model functions (Geophysical Model Functions, GMFs) used for sea surface wind vector calculation include two unknown geophysical parameters of wind direction and wind speed to modulate the normalized radar cross section (NRCS). Among them, the relationship between the normalized radar cross section and the wind speed is an exponential function, and the relationship between the normalized radar cross section and the wind direction is a harmonic function. Therefore, it is i...

AI Technical Summary

Problems solved by technology

However, this method has three shortcomings. First, the inversion accuracy is easily affected by the speckle noise in the SAR image, and the inversion result has a large error; second, there is a problem of local optimal solution in the calculation of sea surface wind vector; third, There is a certain randomness in the selection of the incident angle and its corresponding detection area, which is difficult for commercial application

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