Stepping ISAR imaging method aiming at high-speed air and space object

Abstract

The invention discloses a stepping ISAR imaging method aiming at a high-speed air and space object, and mainly solves the problem that under a large-time-width bandwidth product signal, the difference between a real echo phase of the high-speed air and space object and an approximate echo phase of a one-step-one-stop model leads to the decrease of the imaging effect. The method comprises the steps of: (1) precisely expressing the stepping echo information of the high-speed air and space object; (2) inhibiting doppler fuzzy in the echo information; (3) reconstructing coherence among different sub-bands; (4) removing frequency spectrum center offsets among the sub-bands; (5) carrying out stepping frequency band synthesis and distance matched filtering; and (6) carrying out keystone conversion and finishing orientation focusing. By adopting the method, the stepping ISAR imaging effect of the high-speed air and space object is substantially improved, and the method can be used for carrying out observation, monitoring and imaging on the high-speed air and space object a large-time-width bandwidth product condition.

Description

technical field [0001] The invention relates to the field of radar remote sensing signal processing and remote sensing imaging methods, in particular to a step-by-step ISAR imaging method for fast space and space targets. Background technique [0002] As an all-weather, all-time, and long-distance means of information acquisition, Inverse Synthetic Aperture Radar (ISAR) can complete reconnaissance and surveillance tasks that are difficult for optical radar and infrared radar in complex environments, and obtain high-resolution ISAR 2D imagery. ISAR images can be used to identify and classify moving targets, battlefield early warning and surveillance, aircraft tower control and space target surveillance, etc., and are widely used in military and civilian applications. In order to obtain more detailed characteristic information of the target, it is necessary to obtain a high-resolution ISAR image of the target, which requires the radar to transmit a signal with as large a band...

AI Technical Summary

Problems solved by technology

When the above methods are used for ISAR imaging of fast space and space targets, there is an error between the "one-step-one-stop" echo model and the real situation, which leads to the difference between the echo phases of each step frequency in the imaging process and reduces the frequency band synthesis. Therefore, it cannot solve the problem of fast target stepping frequency ISAR imaging processing.

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