Method for compressed sensing synthetic aperture radar imaging based on dual sparse constraints

Abstract

The invention discloses a method for compressed sensing synthetic aperture radar imaging based on dual sparse constraints. The method mainly solves the problems that a complete SAR image cannot be obtained in imaging through a traditional synthetic aperture radar imaging method and time loss is large. The method comprises a first step of utilizing radar to irradiate a ground sparse scene D and obtain echo signals r of the scene; a second step of constructing an orientation direction base matrix A of the scene and a distance direction base matrix B of the scene; a third step of obtaining an orientation direction measurement matrix theta, a distance direction measurement matrix omega and an echo measurement matrix S according to the orientation direction base matrix and the distance direction base matrix; a fourth step of constructing a Lagrangian function f(Y,U) according to the orientation direction measurement matrix, the distance direction measurement matrix and the echo measurement matrix; and a fifth step of using an alternate iteration multiplier method to solve the Lagrangian function f(Y,U) in the fourth step and obtaining an image of the scene D. The method can achieve high-resolution imaging of synthetic aperture radar in downsampling, is quick in imaging speed and can be used for large-area topographic mapping and cartography.

Description

technical field [0001] The invention belongs to the technical field of radar, in particular to a CS-SAR imaging method of compressed sensing synthetic aperture radar capable of effectively processing large scenes, which can be used for large-area topographic surveying and mapping, cartography, and all-weather global reconnaissance. Background technique [0002] Synthetic Aperture Radar (SAR) is a high-resolution imaging radar with all-day and all-weather imaging capabilities, and has been widely used in military and civilian applications. The high resolution of SAR relies on broadband signals in the radial distance, and the frequency band of hundreds of megahertz can reduce the distance resolution unit to the sub-meter level; in the azimuth, it relies on the movement of the radar platform, which is equivalent to forming a very long linear array in space , and store each echo as a composite array for processing. [0003] The Shannon-Nyquist sampling theorem points out that i...

AI Technical Summary

Problems solved by technology

Although the CS-SAR imaging algorithm can perform imaging at a sampling frequency lower than Shannon-Nyquist, this method often takes a lot of time, cannot achieve real-time imaging processing, and has poor imaging effectiveness, making it only able to process smaller scene

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