Onboard inverse synthetic aperture laser radar micro-motion imaging method under sparse sampling

Abstract

The invention relates to an onboard inverse synthetic aperture laser radar micro-motion imaging method under sparse sampling. The method comprises the following steps: specific to a micro-motion target in the air, building a target motion model, and obtaining a slant-range expression of any point on the target; obtaining a laser radar echo signal model; by estimating a radial speed of the target,constructing a compensation function, and performing radial speed compensation on an echo signal; expressing a fast time domain and a slow time domain in a discretization manner, and dividing a distance direction-azimuth imaging space into N*M grids; specific to the divided distance direction-azimuth imaging space, building an onboard inverse synthetic aperature laser radar micro-motion imaging linear measurement model; and by utilizing a compressive sensing theory, establishing an optimization equation based on an l1 / 2 norm optimization criterion, and solving, thus obtaining an image reconstruction result under the sparse sampling. The method provided by the invention is specific to laser radar detection and can realize high-resolution imaging on the target at a high sparse sampling rate,the azimuth data rate requirement is effectively lowered, and the laser radar imaging quality is improved.

Description

technical field [0001] The invention relates to the technical field of radar imaging processing, in particular to an airborne inverse synthetic aperture laser radar micro-motion imaging method under sparse sampling. Background technique [0002] With the rapid development of laser technology, the Inverse Synthetic Aperture Lidar (ISAL) formed by applying microwave radar imaging technology to the laser band can increase the data rate of radar imaging by more than three orders of magnitude. Due to the combination of coherent laser technology and synthetic aperture technology, the two-dimensional resolution of inverse synthetic aperture lidar has good consistency in distance, and it is the only optical means that can theoretically achieve centimeter-level resolution at distances of thousands of kilometers. At present, due to the short wavelength of lidar, the required pulse repetition frequency is very high, which cannot be achieved by hardware equipment at this stage, and beca...

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Problems solved by technology

[0003] The purpose of the present invention is to address at least some of the above problems, and propose an airborne inverse synthetic aperture lidar micro-motion imaging method for sparse sampling, so as to solve the problem of blurred lidar imaging in the prior art

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