An Airborne Synthetic Aperture Radar Moving Target Imaging Method

Abstract

The invention discloses an airborne synthetic aperture radar moving target imaging method, which is applied in the field of radar technology. By dividing the signal after pulse compression into two channels, the signal of one channel uses the second-order Keystone transformation to correct the second order of the moving target echo. Migration momentum; the signal of another channel can also correct the second-order migratory momentum of the moving target echo by constructing an inverse second-order Keystone transformation, and then multiply the two processed signals by a multiplier to correct the first-order Finally, a better imaging result can be obtained through azimuth matching filtering; the method of the present invention can simultaneously solve the problem of first-order and second-order migration correction of the echo trajectory of the moving target, and achieve a good imaging effect of the moving target; and Compared with the existing moving target imaging algorithm, the steps are more direct and concise, the operation is simpler, and the first-order and second-order migration momentum can be corrected.

Description

technical field [0001] The invention belongs to the field of radar technology, in particular to an imaging technology for ground moving targets by airborne synthetic aperture radar. Background technique [0002] Synthetic Aperture Radar (SAR) ground moving target imaging technology is widely used in various fields today. However, due to the complex movement of ground moving targets, the moving target echo received by SAR usually contains higher first-order and second-order migration momentum, which has a greater impact on the final imaging results. In order to obtain good imaging results, it is necessary to perform migration correction on the echoes of moving targets first, and then focus imaging. [0003] The first-order migration momentum correction of moving targets usually adopts Keystone transformation. ", the Keystone transformation is proposed. Keystone transform has the property of performing first-order migration correction when the motion information is unknown....

AI Technical Summary

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

Images