DSP+FPGA dual-base forward-looking SAR imaging method and imaging device based on enhanced ADC

Abstract

The invention discloses an enhanced ADC-based DSP+FPGA dual-base forward-looking SAR imaging method. It includes the following steps: Step 1. Use the enhanced ADC to sample and digitally down-convert the echo intermediate frequency analog signal to obtain complex baseband data and transmit it to the FPGA; Step 2. Perform range compression, distance walking and FDC correction on the complex baseband data , bending correction and residual migration correction, get the processed data in the range direction, and send it to the DSP; Step 3. Perform high-order polynomial fitting, nonlinear scaling in the azimuth direction, high-order phase filtering in the azimuth direction, deskewing in the azimuth direction, and geometry Correction processing; forming ground distance map. The invention also discloses a dual-base forward-looking SAR imaging device based on enhanced ADC DSP+FPGA, which includes an enhanced analog-to-digital converter, FPGA and DSP, and also includes a network port chip. The invention makes full use of the digital down-conversion function of the analog-to-digital converter, the high-efficiency parallel feature of the FPGA, and the powerful floating-point computing capability of the DSP for large data volumes, and realizes high-resolution imaging of the dual-base forward-looking SAR.

Description

technical field [0001] The invention belongs to the field of communication technology and relates to a bibase forward-looking SAR imaging technology, in particular to an enhanced ADC-based DSP+FPGA bibase forward-looking SAR imaging method and an imaging device. Background technique [0002] The working principle of SAR (Synthetic Aperture Radar) is to use the relative motion of the radar and the target to synthesize the smaller real antenna aperture into a larger equivalent antenna aperture radar by means of data processing. Synthetic aperture radar is characterized by high resolution, can work around the clock, and can effectively identify camouflage and penetrate cover. The bistatic synthetic aperture radar uses a separate transmitter and receiver to fly on different platforms to achieve radar imaging, and use the special flight trajectory of the flying platform to obtain forward-looking SAR images. [0003] At the end of the 1970s, the United States took the lead in car...

AI Technical Summary

Problems solved by technology

Therefore, the main difficulty in the engineering of bistatic forward-looking SAR high-resolution imaging method lies in the real-time processing of large amounts of data

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