Improved ISAR (Inverse Synthetic Aperture Radar) range alignment method capable of removing jump and drift errors

Abstract

The invention discloses an improved ISAR (Inverse Synthetic Aperture Radar) range alignment method capable of removing jump and drift errors, which is mainly used for solving problems of a jump error and a blocking range drift of a global minimum entropy range alignment algorithm. The method comprises the following steps which are executed sequentially: S1, range alignment is carried out on ISAR pulse pressure data by adopting the global minimum entropy algorithm; S2, a normalized correlation coefficient of each echo and an adjacent one-dimensional range profile after range alignment is calculated; S3, whether echo data is a jump pulse or not through analyzing the normalized correlation coefficient; S4, pulses of blocking range drift are aligned through mutually correlating the jump pulse and an adjacent pulse; S5, image processing is carried out on alignment data acquired in the step S4 to acquire edge tracks of a range alignment image; S6, an inclination angle of the two edge tracks acquired in the step S5 is calculated by using Radon transform; and S7, inclination correction is carried out on the alignment data acquired in the step S4 according to the inclination angle acquired in the step S6 so as to acquire an ISAR high-precision range alignment result.

Description

technical field [0001] The invention belongs to radar imaging technology, in particular to an ISAR imaging technology. Background technique [0002] Inverse-Synthetic-Aperture-Radar (ISAR) range alignment is to eliminate the dislocation of adjacent echoes caused by the translation of the target relative to the radar in the upward distance. After alignment, the signals of the same scattering point on the target are located in the same distance unit in different echo pulses. Typical algorithms include: adjacent envelope cross-correlation method, cumulative cross-correlation method in time domain and frequency domain, envelope maximum modified kurtosis method, global alignment algorithm and global minimum entropy algorithm, etc. The global minimum entropy algorithm is based on the principle of the minimum entropy of the average range profile (ARP) as the alignment basis, and the alignment effect is better through an iterative method. This type of algorithm does not have high ...

AI Technical Summary

Problems solved by technology

[0004] Purpose of the invention: In order to overcome the deficiencies of the prior art, the present invention provides an improved ISAR range alignment method capable of removing jump and drift errors, which is used to solve the jump and jump of the existing range alignment algorithm in the case of complex target motion. Imaging defocus and ghosting problems caused by block drift error

Images