Airborne synthetic aperture radar moving target imaging method

Abstract

The invention discloses an airborne synthetic aperture radar moving target imaging method, which is applied to the technical field of radar. According to the invention, a signal is divided into two channels after pulse compression, the signal of one channel corrects second-order migration of moving target echo by using second-order Keystone transform; the signal of the other channel can also perform correction on the second-order migration of the moving target echo through constructing inverse second-order Keystone transform, then the two pressed signals are multiplied through a multiplier, first-order migration can be corrected, and finally a good imaging result can be obtained through azimuth matching and filtering. According to the method disclosed by the invention, a problem of first-order migration and second-order migration correction for a trajectory of the moving target echo can be simultaneously solved, and a good moving target imaging effect is achieved; and compared with theexisting moving target imaging algorithm, the method is more direct and concise in step, simpler in operation and capable of correcting the first-order and second-order migration.

Description

Technical field [0001] The invention belongs to the field of radar technology, and particularly relates to an airborne synthetic aperture radar imaging technology for ground moving targets. Background technique [0002] The synthetic aperture radar (Synthetic Aperture Radar, SAR) ground moving target imaging technology is widely used in various fields today. However, due to the complex movement of the moving target on the ground, the moving target echo received by the SAR usually contains higher first-order migration and second-order migration, which has a greater impact on the final imaging results. In order to obtain good imaging results, it is necessary to first perform migration correction on the moving target echo, and then perform focus imaging. [0003] The first-order migration momentum correction of moving targets usually uses Keystone transformation. In the literature: "Perry RP, Dipietro RC, Fante R. SAR imaging of moving targets[J].IEEE Transactions on Aerospace&Electr...

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Problems solved by technology

Then when there is acceleration in the radial velocity of the moving target, the second-order term of the migration trajectory cannot be ignored, but the Keystone transformation cannot directly remove the second-order migration of the echo trajectory

[0004] In the literature: "Yang J, Zhang Y.An Airborne SAR Moving Target Imaging andMotion Parameters Estimation Algorithm With Azimuth-Dechirping and the Second-Order Keystone Transform Applied[J].IEEE Journal of Selected Topics inApplied Earth Observations&Remote Sensing,2015,8(8 ):3967-3976.", the second-order Keystone transform and Radon transform are proposed to correct the first-order and second-order migration of the migration trajectory, but the Radon transform requires a complicated process of searching parameters, which greatly increases the amount of calculation

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