System and imaging method for airborne synthetic aperture laser radar

Abstract

The invention discloses a system and imaging method for an airborne synthetic aperture laser radar. The airborne synthetic aperture laser radar comprises a laser unit, a microwave unit, a data collecting and recording device (AD), a stabilized platform, a position and attitude measurement system (POS) and the like. Microwave broadband signals are modulated into a laser frequency band through a laser phase modulator to be emitted out, and laser emitting signals coupled with part of power enter in a receiving end for system calibration processing, range pulse compression and random initial phase correction. Filtering processing is carried out on echo signals in a frequency domain to eliminate the influence of residual vibration on imaging after vibration attenuation of the stabilized platform. The azimuth resolution is achieved, meanwhile, the image signal-to-noise ratio is improved through sub-band image incoherent accumulation processing, and coherent speckles are restrained. The synthetic aperture laser radar imaging method combining a microwave SAR imaging technology and a laser imaging technology is provided, and the fusion development of an optical remote sensing technology and a microwave remote sensing technology is promoted.

Description

technical field [0001] The invention belongs to the field of synthetic aperture radar (Synthetic Aperture Radar, SAR) and optical remote sensing technology, in particular to an airborne synthetic aperture laser radar system and an imaging method. It specifically relates to a synthetic aperture lidar (Synthetic Aperture Ladar, SAL) system design method that applies synthetic aperture radar imaging technology to the laser band, especially the method of using an airborne platform to realize synthetic aperture lidar and using the radar system for imaging . Background technique [0002] The spatial resolution of both optical imaging systems and lidar imaging systems is limited by the system aperture. For a certain working band and a certain system aperture, the resolution will decrease with the increase of the distance. Therefore, high-resolution long-distance imaging requires a large system aperture. However, in the actual system, many factors limit the increase of the system...

AI Technical Summary

Problems solved by technology

[0009] The technical problems to be solved by the present invention mainly include the following points: designing the overall scheme of airborne synthetic aperture laser radar to adapt to the airborne platform; solving the technical problem of coherent modulation of high-sensitivity laser signals; solving the problem of high-resolution laser imaging caused by motion and phase errors influences

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