A data acquisition method of geo SAR interferometric system

Abstract

The invention provides a GEO SAR interference system data acquiring method. According to the method, a rotation decorrelation coefficient is utilized for eliminating deltaKx<^> having no contribution to height measurement, wherein the deltaKx<^> is spatial spectrum shift of range direction in a ground projection direction during first track operation of a GEO SAR system; rotation decorrelation is reduced to improve correlation. Rotation decorrelation is minimized, the deltaKx<^> is minimized through minimizing gamma r, so the spatial spectrum superposition portion of orientation direction in the ground projection direction reaches the largest. Through the method, a problem that GEO SAR interference data generated through a low track SAR interference data acquisition method based on a zero Doppler center in the prior art contains obvious rotation decorrelation is solved.

Description

technical field [0001] The invention relates to the technical field of synthetic aperture radar, in particular to a data acquisition method of a GEO SAR interference system. Background technique [0002] Synthetic Aperture Radar (SAR) is an all-weather, all-time high-resolution microwave remote sensing imaging radar that can be installed on aircraft, GEO SAR, missiles and other flying platforms. Since its invention in the 1950s, it has been widely used in many fields, such as disaster control, vegetation analysis, microwave remote sensing and other fields. Geosynchronous Orbit Synthetic Aperture Radar (GEO SAR) is a SAR operating on a geosynchronous elliptical orbit at an altitude of 36000km. Compared with low-orbit SAR (LEO SAR, the orbit altitude is lower than 1000Km), GEO SAR has the characteristics of large imaging range, short revisit time, strong anti-strike and anti-destroy capabilities, and has become a research hotspot at home and abroad. Interference processing i...

AI Technical Summary

Problems solved by technology

The biggest difficulty in GEO SAR interferometric processing lies in the high orbital altitude of GEO SAR, the serious perturbation effect and the large equivalent forward slope angle

These factors cause the GEO SAR interferometric system to face the special problems of non-parallel heavy-orbit trajectories and squint illumination (such as figure 1 shown)

[0003] Under the influence of the above characteristics, the traditional low-orbit SAR interferometric data acquisition method based on the zero-Doppler center (that is, the GEO SAR position corresponding to the zero-Doppler frequency of the SAR system is used as the synthetic aperture center for data acquisition) will make the generated The pair of heavy orbit GEO SAR interferometric data (the first track data and the second track data) is due to the mismatch of the spatial spectrum in the direction of the azimuth ground projection (such as figure 2 shown) resulting in significant rotational decorrelation

This decorrelation will increase the difficulty of subsequent interferometric processing and reduce the accuracy of elevation and deformation inversion

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