Related motion error compensation method based on BiSAR echoing, system and application

Abstract

The invention belongs to the technical field of radar imaging and discloses a related motion error compensation method based on BiSAR echoing, a system and application. Through BiSAR signal modeling and wave number vector decomposition, image spectrum analytical expression under polar coordinates is obtained, and a correlation between a phase error caused by a motion error and non-systematic distance unit migration is found; and a phase error is roughly estimated by methods of combined estimation and compensation. FFBP imaging treatment is conducted on an echoing signal, so that an SAR image under the polar coordinates before error compensation is obtained; the image is converted to a distance compression-orientation frequency domain, and rough estimation of a phase error thereof is conducted, so that the rough phase error is obtained; and NsRCM is compensated with the phase error obtained by rough estimation, and then phase error fine estimation and fine compensation are carried out,so that image focusing quality is finally improved. The method, system and application disclosed by the invention greatly reduce dependence on a high-precision inertial navigation measurement system and have high processing efficiency and engineering practicability.

Description

technical field [0001] The invention belongs to the technical field of radar imaging, and in particular relates to an echo-based BiSAR correlation motion error compensation method, system and application under a Fastfactorized back projection (FFBP) processing framework. Background technique [0002] Synthetic aperture radar (SAR) has the characteristics of all-weather, all-time and long-range effects, and has a wide range of applications in military and civilian fields such as missile guidance, earth observation, disaster monitoring and environmental protection, while bistatic SAR The configuration of (bistatic SAR, BiSAR) is more flexible, and it can obtain richer target scattering information. In addition, due to the concealed characteristics of its receiving station, it can greatly improve its survivability on the battlefield. Therefore, BiSAR has been widely used. Attention, the research on BiSAR has also been a hot spot in recent years. [0003] However, compared with...

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Problems solved by technology

[0006] (1) In airborne BiSAR, unknown motion errors will be introduced due to factors such as airflow and the instability of the carrier platform, which seriously affect the focusing quality of BiSAR imaging

[0007] (2) For the problem of motion errors, high-precision inertial navigation equipment can be equipped to measure motion errors and perform error compensation. However, high-precision inertial navigation equipment is expensive, bulky, and even restricted by imports. Therefore, it is difficult for the existing BiSAR system to be equipped with high-precision High-precision inertial navigation equipment, it is difficult to use measurement methods to compensate for errors

[0008] (3) Compared with the traditional frequency-domain imaging algorithm, the time-domain fast imaging algorithm has more advantages in processing BiSAR, and the existing self-focus error algorithm is usually combined with frequency-domain imaging processing, which is difficult to process in time-domain fast imaging processing. application

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