Contrast optimization self-focusing method based on hypersonic platform synthetic aperture radar (SAR)

Abstract

The invention discloses a contrast optimization self-focusing method based on a hypersonic platform synthetic aperture radar (SAR), which mainly solves the problems of dependence on initial closed interval division and low convergence rate in the prior art. The method comprises the following steps of: 1) transmitting linear frequency modulation pulse signals to the ground by using a radar; 2) receiving radar echo signals by using an antenna and performing distance-to-pulse compression on the echo signals; 3) selecting M distance units with highest signal intensity from the echo signals subjected to the distance-to-pulse compression and performing Doppler frequency modulation rate estimation on the selected distance units; 4) calculating the Doppler frequency modulation rate of each distance unit of the echo signals according to the optimal Doppler frequency modulation rate estimation value; and 5) constructing reference function according to the Doppler frequency modulation rate and performing orientation-to-pulse compression on the echo signals subjected to the distance-to-pulse compression to acquire the final SAR imaging result. The method has the advantages of high convergence rate and no dependence on initial closed interval division and can be applied to motion compensation of hypersonic platform SAR imaging.

Description

technical field [0001] The invention belongs to the technical field of radar, and specifically relates to a self-focusing method for estimating and compensating a secondary phase error by using the principle of optimal image contrast, which is used for motion compensation during hypersonic platform synthetic aperture radar imaging. Background technique [0002] The application of synthetic aperture radar SAR imaging technology to hypersonic platform HSV is a frontier topic of exploration at home and abroad. Hypersonic platform-borne synthetic aperture radar HSV-SAR imaging technology is the basis for realizing the recognition and positioning of ground moving and stationary targets. Due to the high maneuverability of HSV, its actual track will inevitably deviate from the ideal state of constant speed, contour, and straight line. The existence of motion error affects the phase and amplitude of the echo signal, causing defocusing in the azimuth direction after imaging, blurrin...

AI Technical Summary

Problems solved by technology

The convergence speed of the algorithm has been further improved, but this type of method, like the enumeration method, needs to rely on the division

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