Synthetic aperture radar (SAR) imaging method based on field programmable gate array (FPGA)

Abstract

The invention discloses a synthetic aperture radar (SAR) imaging method based on field programmable gate array (FPGA). The SAR imaging method based on the FPGA mainly solves the problems that an existing system is complex in structure and slow in data processing speed. The SAR imaging method based on the FPGA comprises the following steps: calling a multiplying unit in the FPGA, conducting fast Fourier transform (FFT) operation after multiplying each array of distance direction data and hamming window data after quantification, finishing distance pulse pressure; calculating a scene central location of the distance direction by inertia parameters, intercepting the distance direction data; transposing acquired data by interception, realizing to store aperture data based on direction; estimating a Doppler central value and a Doppler frequency modulation rate based on inertia navigation parameters; constructing a Doppler frequency shift function, a Doppler frequency modulation function and a direction hamming window function based on the estimated Doppler central value and the Doppler frequency modulation rate; conducting FFT operation by multiplying each array of the direction data after finishing the distance impulse pressure with the Doppler frequency shift function, the Doppler frequency modulation function and the direction hamming window function, and acquiring final imaging data. The SAR imaging method based on the FPGA has the advantages of simplifying an SAR imaging system structure, improving processing speed, and capable of being used in the SAR imaging under a missile-borne module.

Description

technical field [0001] The invention belongs to the technical field of digital signal processing, relates to a radar imaging method, and can be applied to the design of radar real-time signal processing systems, remote sensing, missiles and other fields. Background technique [0002] Synthetic Aperture Radar (SAR) has high resolution in two-dimensional range and azimuth, and can perform high-resolution two-dimensional imaging of the scene. It can detect and locate targets all-weather, all-day, and long-distance, and plays an important role in military and many civilian fields. Common SAR imaging algorithms include range-Doppler R-D algorithm, line frequency modulation scaling CS algorithm and so on. Range-Doppler imaging algorithm, as a main algorithm of synthetic aperture radar imaging, plays an important role in the field of synthetic aperture radar imaging. [0003] At present, the commonly used radar imaging platform mostly adopts the form of FPGA+DSP. Taking advantage...

AI Technical Summary

Problems solved by technology

In this form, although DSP has the ability to complete complex operations, it is implemented based on seriality, its parallelism is low, resource utilization is insufficient, and the operation speed is slow.

Moreover, the complex multi-board form of FPGA+DSP has high requirements on system space and heat dissipation conditions, while the environmental space and heat dissipation conditions of the missile-borne SAR system are limited, which cannot meet the requirements of FPGA+DSP multi-board card imaging platform

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