ISAR imaging method for complex moving target

Abstract

The invention discloses a complex moving target ISAR imaging method based on a quasi-time-frequency bilinear coherence algorithm, and the method comprises the following steps: obtaining the echo dataof a target, and carrying out the distance compression and translation compensation of an echo signal; extracting data from the signal along the distance direction, and calculating an improved cubic phase function MCPF of an extraction result; performing Radon-CPF-Fourier transform on the MCPF, and obtaining a three-dimensional data matrix in a Doppler center-polar radius-polar angle domain; and projecting the three-dimensional data matrix to a Doppler central axis along a polar radius and a polar angle, and generating a final high-resolution inverse synthetic aperture radar (ISAR) image by recombining all distance-Doppler centers. According to the method, the cross term interference suppression of a cubic phase function can be realized under the condition of no time-frequency resolution loss, the signal gain is improved, the calculation performance is improved, and a clear maneuvering target ISAR image is obtained.

Description

technical field [0001] The invention belongs to the field of radar technology, in particular to an ISAR imaging method for complex moving targets in the field of signal processing, which can be used for ISAR imaging of non-cooperative and high-speed maneuvering targets. Background technique [0002] The traditional optical imaging technology has extremely high requirements on the external environment, especially the light conditions, so the scope of application is limited. With its advantages of all-weather, all-day, long-distance and high-resolution radar images in different frequency bands and different polarization conditions, radar imaging technology makes up for the shortcomings of optical imaging and greatly improves the efficiency of information acquisition in harsh light environments. It has great practical value for civilian use (such as terrain surveying, celestial observation, ocean observation, crop assessment, disaster forecasting, etc. Synthetic aperture radar ...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the problem of low imaging resolution, Lv et al. proposed a range-Doppler center (RCD) ISAR imaging algorithm based on quasi-time-frequency transformation (Lv distribution), which better achieves cross-term suppression without generating time-frequency resolution loss

However, this method is only applicable to linear frequency modulation (LFM) signals, and the performance is significantly reduced when dealing with third-order phase modulation signals (secondary frequency modulation signals) signals used for maneuvering target models

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