Airborne SAR motion compensation method based on inertial navigation system parameters

Abstract

The invention discloses a motion compensation method based on inertial navigation system parameters, which comprises the following steps of establishing a radar coordinate system and a motion error model, and collecting the inertial navigation system parameters in real time, establishing an instantaneous slant distance equation of the airborne SAR to obtain an instantaneous slant distance error formula, and separating an influence value deltaR of position errors of the aerial carrier along the Y axis and the Z axis on the instantaneous slant distance error and an influence value deltaRx of position errors of the aerial carrier along the X axis direction on the instantaneous slant distance error, then calculating the actual course angle and the actual course speed of the aerial carrier by using the parameters of the inertial navigation system, projecting the speed of the actual course of the aerial carrier to a radar coordinate system to obtain the actual positions of the aerial carrier along the X-axis, Y-axis and Z-axis directions, sequentially calculating deltaR, deltaRx and an envelope compensation function H1, and performing envelope compensation on the echo signal, and finally, calculating a phase compensation function H2, and performing phase compensation on the echo signal, thereby completing motion compensation of the echo signal.

Description

technical field [0001] The invention belongs to the field of flight airborne radar imaging, and relates to a motion compensation method based on inertial navigation system parameters, specifically an accelerometer and gyroscope based on an inertial measurement unit (IMU) or an inertial navigation system (INS). The method of motion compensation based on the parameter data can be applied to compensate the position error caused by the unsteady motion of the airborne SAR platform, and obtain high-quality SAR images. Background technique [0002] Synthetic Aperture Radar (SAR) has the advantages of all-time, all-weather, long-distance, high-resolution and wide swath, and has been widely used in various fields. For example, in terms of military reconnaissance, high-resolution images obtained by synthetic aperture radar are an important means to understand the battlefield situation and obtain enemy intelligence; in terms of microwave remote sensing, images obtained by synthetic ape...

AI Technical Summary

Problems solved by technology

[0004] The imaging algorithm is based on the model of the carrier aircraft flying straight along the ideal heading, but in reality, the airborne SAR flight is easily affected by the airflow, causing the flight trajectory of the carrier aircraft to deviate from the ideal position, which will lead to Image quality degrades or even fails to image

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