Aircraft SAR real-time imaging method

Abstract

The invention provides an aircraft SAR real-time imaging method, which comprises the following steps that: radar works in an intermittent Burst imaging mode, firstly, Doppler center frequency estimation is performed on single Burst echo data in combination with inertial navigation information, and Doppler frequency modulation rate estimation is performed in combination with the Burst echo data and a Doppler center frequency estimation value thereof; then, acceleration compensation is carried out on the Burst echo data, an improved ECS algorithm is adopted to complete Burst echo imaging preprocessing, sub-aperture data are divided through a time domain, azimuth FFT is carried out to obtain multiple sub-aperture images, and Burst images are obtained through multi-view processing; and finally, SAR positioning, registration and splicing are carried out on the plurality of Burst images to obtain a complete SAR image. The method is used for solving the problem that an existing SAR sub-aperture imaging algorithm cannot meet the real-time matching navigation requirement, precision and efficiency can be considered, the requirement for storage resources is not high, implementation is easy, and a high application value is achieved.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, in particular to an aircraft SAR real-time imaging method. Background technique [0002] Compared with other detection and perception systems, the SAR imaging system has many advantages such as all-weather, all-time, high-resolution, etc., and can realize precise guidance and aircraft positioning through image matching. Different from airborne and spaceborne platforms, the application scenarios of highly maneuverable aircraft such as UAVs and missiles determine its outstanding characteristics such as high speed, high maneuverability, and non-linear flight paths, which lead to geometric deformation, Problems such as large distance migration and large changes in Doppler parameters have put forward high requirements for error compensation and real-time performance on imaging algorithms. [0003] At present, the sub-aperture method is often used to solve the problem of SAR imaging on...

AI Technical Summary

Problems solved by technology

The advantages of the SPECAN algorithm are high imaging efficiency and easy hardware implementation, but the algorithm is based on a simple model and cannot correct the empty variable of range migration, and the imaging resolution is low; the ECS algorithm can realize accurate correction of space-variable distance migration, but the azimuth There are many zero padding points for frequency modulation conversion, and the hardware implementation is difficult and the real-time performance is poor.

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