Field programmable gate array (FPGA) based inverse synthetic aperture radar (ISAP) imaging parallel envelope alignment method

Abstract

The invention discloses an FPGA based ISAP imaging parallel envelope alignment method. The method comprises performing FFT, eight-time zero padding and IFFT processing on range data, wherein processed data are output as the result if the processed data are a first group of radar data, otherwise, the data are not output; performing modulus calculation, square root extraction and FFT processing on the data, determining whether the processed data are the first group of radar data, saving the data into the FIFO and jumping to the entrance position if the data are the first group of radar data, and performing complex conjugate multiplication on the data and the previous group of data saved in the FIFO to calculate a modified function if the data are not the first group of radar data; multiplying the modified function by the group of echo data; performing IFFT to obtain results of the group after envelope alignment; performing modulus calculation, square root extraction and FFT processing on the group of results, storing the results in the FIFO to be used for the next group of data, and repeating the steps till all echo data are processed. According to the method, FPGA based parallel radar signal envelope alignment is mainly achieved, high accuracy and the high real-time property of ISAR imaging are achieved, the scheme is simple, power consumption is low, and the processing speed is high.

Description

technical field [0001] The invention belongs to the field of digital signal processing of radar systems, and in particular relates to a method for realizing parallel envelope alignment of inverse synthetic aperture radar (ISAR) imaging by using a field programmable gate array (FPGA), specifically a method for parallel envelope alignment of ISAR imaging based on FPGA. Real-time imaging processing for inverse synthetic aperture radar ISAR. Background technique [0002] Inverse synthetic aperture radar (ISAR) regards the radar as a reverse motion based on the moving target when the radar carrier platform does not move. And use the relative movement between the two to continuously transmit and receive signals to achieve all-weather, all-time, long-distance acquisition of fine images of non-cooperative targets (such as aircraft, ships and missiles, etc.), which has important military and civilian values . Due to the non-cooperative nature of the imaging objects of inverse synth...

AI Technical Summary

Problems solved by technology

[0003] Envelope alignment is one of the key technologies for translational compensation of inverse synthetic aperture radar ISAR imaging. The current engineering implementation mainly adopts the realization method with DSP as the core; with the development of national defense technology, the inverse synthetic aperture radar ISAR imaging The accuracy and real-time requirements are getting higher and higher, and the characteristics of DSP serial processing, the processing speed is limited by the main frequency of the processor, which is increasingly unable to meet the needs of national defense scientific research practice and development. At the same time, the DSP hardware system has a complex structure and is difficult to debug , is easily affected by external electromagnetic fields and current noise, which may cause the radar system to crash sometimes. The implementation method using DSP as the core is far from meeting the requirements of large amount of computation, high real-time, and high stability for inverse synthetic aperture radar (ISAR) imaging. For inverse synthetic aperture radar ISAR imaging, it is urgent to study a new high real-time, high stability inverse synthetic aperture radar ISAR imaging parallel envelope alignment method to meet the development trend of stronger computing power and higher processing speed

Images