Method for improving quality of three-dimensional interferometric inverse synthetic aperture radar image

Abstract

The invention discloses a method for improving the quality of a three-dimensional interferometric inverse synthetic aperture radar (ISAR) image. The method comprises the following steps: pre-processing echo data; carrying out azimuth aperture extrapolation on the echo data by using a spectrum estimation technology to obtain an interference pair of a super-resolution two-dimensional interferometric synthetic aperture radar image; registering the super-resolution two-dimensional interferometric synthetic aperture radar image and carrying out interference processing to obtain the three-dimensional interferometric inverse synthetic aperture radar image under different spectrum estimation technologies. The step of pre-processing the data comprises movement compensation processing on the echo data of each antenna platform, compensation of a wave path difference between antennas and elimination of migration though resolution cell by Keystone conversion; a Capon spectrum estimation technology and a Burg spectrum estimation technology are used for carrying out the azimuth aperture extrapolation to obtain the super-resolution two-dimensional ISAR image pairs under different methods; by adopting the method, a high-quality actual measurement target three-dimensional view can be obtained and the method has very important meanings on ISAR target identification and posture determination.

Description

Technical field [0001] The present invention relates to Interferometric Inverse Synthetic Aperture Radar Imaging (Interferometric Inverse Synthetic Aperture Radar Imaging) technology. Background technique [0002] ISAR can acquire two-dimensional images of long-distance targets all the time and in all weather, which has attracted widespread attention. Generally speaking, the image obtained by ISAR is the projection of a three-dimensional target on the range-Doppler plane. However, for a maneuvering target, its rotation rate is unknown, which makes it difficult to calibrate the target's ISAR image. On the other hand, the projection of the maneuvering target relative to the radar is different under different attitudes and motion conditions, which leads to different ISAR images obtained. Both aspects increase the difficulty of ISAR target recognition and attitude determination. [0003] In order to obtain the true three-dimensional view of the target, people proposed the 3D InISAR ...

AI Technical Summary

Problems solved by technology

High azimuth resolution is obtained through the larger rotation angle of the target relative to the radar. However, the maneuvering movement of the target at this time will make the echo phase history nonlinear, resulting in serious defocus of the image obtained by traditional Fourier transform imaging; the linear time-frequency analysis method While maintaining the phase, it usually leads to a decrease in resolution, which is not conducive to obtaining isolated scattering points; while nonlinear time-frequency analysis methods will generate cross terms, and their phases are often destroyed

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