Maximum A Posteriori Estimation Angle Super-resolution Imaging Method Based on Generalized Gaussian Constraints

Abstract

The invention discloses a maximum a posteriori estimation angle super-resolution imaging method based on generalized Gaussian constraints. Aiming at the problem of low azimuth angle resolution of real-beam radar in the prior art, the method provided by the invention uses the maximum a posteriori probability density function value of the target scattering coefficient as an estimate of the target scattering coefficient, and under different discrete parameters, different targets are statistically The characteristics and noise statistics are constrained by the generalized Gaussian distribution and used as prior information, and then the deconvolution problem of calculating the target scattering coefficient is transformed into a regularized estimation problem with a variable regularization term, and finally the conjugate gradient algorithm is used Realize the solution of the regularization estimation problem, and transform the solution method into an iterative operation, and finally realize the radar angle super-resolution imaging, which solves the problem of low azimuth angle resolution in the scanning imaging mode.

Description

technical field [0001] The invention belongs to the technical field of radar imaging, and is particularly suitable for a super-resolution method of real beam scanning radar azimuth angle. Background technique [0002] The all-day and all-weather working characteristics of radar make radar widely used in civilian fields. Radar forward-looking high-resolution imaging requires both range and azimuth to have high resolution. Realizing high-resolution imaging of the radar platform's forward-looking area can make it play a huge role in ground search, environmental monitoring, long-distance reconnaissance and other fields. [0003] Real-beam scanning radar is a commonly used radar working mode. Through the mechanical scanning of the real-aperture antenna, the imaging area is irradiated successively and the target scattering coefficient information is obtained. The high resolution in the range direction can be achieved by transmitting a chirp signal and using the range pulse compre...

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Problems solved by technology

[0004] The literature "S.M.Sherman and D.K.Barton, Monopulse principles and techniques. Artech House, 2011" proposes a method using monopulse technology, which can achieve high resolution in azimuth for a single target, but this method cannot distinguish multiple targets in the same lobe

Prez-Martnez et al in the literature "F.Prez-Martnez, J.Garcia-Fominaya, and J.Calvo-Gallego, A shift-and-convolution technique for high-resolution radar images. Sensors Journal, IEEE, vol.5, no. 5, pp.1090–1098, 2005.” proposed a shifted convolution technique to achieve high-resolution imaging of real-beam radar, but this method only achieves high resolution in the range direction, and does not improve the resolution in the azimuth direction

Literature "S.Uttam and N.A.Goodman, Superresolution of coherent sources in real-beam data, Aerospace and Electronic Systems. IEEE Transactions on, vol.46, no.3, pp.1557–1566, 2010" and literature "Y.Zhang, Y. Zhang, Y. Huang, J. Yang, Y. Zha, J. Wu, and H. Yang, Ml iterative superresolution approach for real-beam radar. in Radar Conference, 2014IEEE. IEEE, 2014, pp.1192–1196” proposed to use the method of spectral estimation to achieve azimuth super-resolution imaging, but the problem of how to get enough snapshots for the motion platform has not been solved, and the problem of how to improve the effectiveness of the calculation still exists

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