Synthetic aperture sonar motion compensation method based on combination of multiple sensors

Abstract

The invention relates to the technical field of imaging sonar signal processing and synthetic aperture sonar motion compensation, in particular to a synthetic aperture sonar motion compensation methodbased on the combination of multiple sensors. The method comprises the following steps that: on the basis of a synthetic aperture sonar motion measurement system, obtaining sonar motion speed measured by inertial navigation, and sonar motion speed measured by a Doppler velocity log; combining the sonar motion speed measured by the inertial navigation with the sonar motion speed measured by the Doppler velocity log to obtain the optimal estimation value of the sonar motion speed; carrying out integration on the optimal estimation value of the sonar motion speed, and calculating the practical plane flight path and the sky direction flight path of the sonar; according to the practical plane flight path and the sky direction flight path of the sonar, carrying out fitting on an ideal plane flight path and the sky direction flight path under a least squares criterion; calculating a swaying error between the ideal plane flight path and the practical plane flight path of the synthetic aperture sonar; calculating a heaving error between the practical sky direction flight path and the ideal sky direction flight path of the synthetic aperture sonar; and calculating a practical sonic path distance difference, and carrying out conversion to obtain a time delay to compensate echo data collected by the synthetic aperture sonar.

Description

technical field [0001] The invention belongs to the technical field of imaging sonar signal processing and synthetic aperture sonar motion compensation, and in particular relates to a synthetic aperture sonar motion compensation method based on multi-sensor combination. Background technique [0002] Synthetic aperture sonar uses the movement of the small-aperture matrix along the azimuth direction (track direction) to synthesize a virtual large aperture, and performs coherent superposition processing on the received echoes at different positions according to the spatial position and phase relationship to obtain high-resolution images. The prerequisite for synthetic aperture sonar to achieve high-quality imaging is that the sonar moves in a straight line at a constant speed along the azimuth direction. In actual work, affected by factors such as water flow, wind and waves, the synthetic aperture sonar will deviate from the ideal motion state and produce motion errors. The far...

AI Technical Summary

Problems solved by technology

However, the premise of Kalman filtering to achieve optimal estimation is that the model is accurate and the statistical characteristics of random interference signals are known, which is often difficult to achieve in real systems; and for Kalman filtering, model differences can easily lead to estimation accuracy degradation and filtering divergence The phenomenon that causes the problem that the sonar movement speed cannot be accurately calculated

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