CN-122017832-A - Inverse synthetic aperture radar imaging method, system, terminal equipment and medium with phase distortion and two-dimensional compressed sampling

CN122017832ACN 122017832 ACN122017832 ACN 122017832ACN-122017832-A

Abstract

The invention discloses an inverse synthetic aperture radar imaging method, an inverse synthetic aperture radar imaging system, terminal equipment and a medium with phase distortion and two-dimensional compressed sampling, and relates to the technical field of radar imaging. The method comprises the steps of constructing a sparse recovery model containing phase error correction based on a low-rank and sparsity principle, wherein the sparse recovery model is adaptive to two-dimensional compressed sampling and has phase distortion of an inverse synthetic aperture radar echo signal, and solving the sparse recovery model based on a unified alternate direction multiplier method frame to complete sparse recovery and phase error correction of the two-dimensional compressed sampling signal and output an inverse synthetic aperture radar image. The invention solves the problems that the existing inverse synthetic aperture radar imaging ignores phase errors and phase correction fails in downsampling, can generate clear images, and reduces the computational complexity.

Inventors

ZHANG YUNJIAN
PAN PINGPING
LIU JINYI

Assignees

深圳开鸿数字产业发展有限公司

Dates

Publication Date: 20260512
Application Date: 20251215

Claims (16)

1. A method of inverse synthetic aperture radar imaging with phase distortion and two-dimensional compressed sampling, the method comprising: Based on a low-rank and sparsity principle, constructing a sparse recovery model containing phase error correction, wherein the sparse recovery model is adaptive to an inverse synthetic aperture radar echo signal which is sampled in a two-dimensional compression mode and has phase distortion; based on a unified alternate direction multiplier method frame, solving the sparse recovery model to finish sparse recovery and phase error correction of the two-dimensional compressed sampling signal, and outputting an inverse synthetic aperture radar image.
2. The method of claim 1, wherein constructing a sparse recovery model including phase error correction based on low rank and sparsity principles comprises: defining a matrix form of an inverse synthetic aperture radar signal model with fully sampled measurements; performing two-dimensional compressive sampling operation on the matrix form of the inverse synthetic aperture radar signal model to obtain a down-sampled signal model; Because the phase error matrix is a diagonal matrix, the downsampled signal model is rewritten; for radar data downsampled in two dimensions and with phase distortion, an inverse synthetic aperture radar imaging problem with low rank and sparsity constraints is defined.
3. The method of inverse synthetic aperture radar imaging with phase distortion and two-dimensional compressed sampling according to claim 2, characterized in that the matrix form of the inverse synthetic aperture radar signal model with fully sampled measurements is represented as: Wherein, the The radar data representing the full sample is displayed, Representing an inverse synthetic aperture radar image, An additive white gaussian noise representing a full sample, A fourier matrix representing the distance dimension is presented, A fourier matrix representing the azimuth (transverse distance dimension), Representing the phase error matrix of the full sample, Representing the conjugate transpose operation.
4. A method of inverse synthetic aperture radar imaging with phase distortion and two-dimensional compressive sampling as claimed in claim 3, wherein the two-dimensional compressive sampling operation is performed on a matrix form of the inverse synthetic aperture radar signal model, and the resulting downsampled signal model is expressed as: Wherein, the Indicating a downsampling operation.
5. The method of inverse synthetic aperture radar imaging with phase distortion and two-dimensional compressed sampling of claim 4, wherein because the phase error matrix is a diagonal matrix, the downsampled signal model is rewritten as: Wherein, the , And is also provided with 。
6. The method of inverse synthetic aperture radar imaging with phase distortion and two-dimensional compressed sampling of claim 5, wherein for radar data downsampled in two dimensions and with phase distortion, an inverse synthetic aperture radar imaging problem with low rank and sparsity constraints is represented as: Wherein, the Representing a kernel norm, characterizing a rank of the matrix, and being equal to a sum of singular values; Representing a matrix The norm of the sample is calculated, Representing the Frobenius norm, To determine the regularization coefficients of low rank extent of the recovered radar data, Is a regularization coefficient for determining sparsity of the reconstructed inverse synthetic aperture radar image.
7. The method of claim 5, wherein the solving the sparse recovery model based on a unified alternate direction multiplier framework to accomplish sparse recovery and phase error correction of two-dimensional compressed sampled signals, outputting an inverse synthetic aperture radar image, comprises: Constructing an augmented lagrangian function; And iteratively solving a plurality of minimization sub-problems by using an alternate direction multiplier method solver, and outputting an inverse synthetic aperture radar image.
8. The method of inverse synthetic aperture radar imaging with phase distortion and two-dimensional compressed sampling of claim 7, wherein the constructed augmented lagrangian function is expressed as: Wherein, the Representing the lagrangian multiplier and, Representing penalty parameters.
9. The method of inverse synthetic aperture radar imaging with phase distortion and two-dimensional compressed sampling of claim 8, wherein the number of minimization sub-problems comprises: Wherein, the Represent the first A number of iterations of the process are performed, The entropy of the image is represented and, Is the phase vector to be compensated.
10. The method of claim 1, wherein the sparse mode of two-dimensional compressed samples comprises at least one of a root mean square mode, a separable root mean square mode, a gaussian random mask mode, and a mixed sparse mode.
11. The method for imaging an inverse synthetic aperture radar with phase distortion and two-dimensional compressed sampling of claim 1, wherein the noise in the data of the inverse synthetic aperture radar echo signal is additive white gaussian noise, and the sparse recovery model suppresses the noise by using Frobenius norm constraint.
12. An inverse synthetic aperture radar imaging system with phase distortion and two-dimensional compressed sampling, the system comprising: The sparse recovery model construction module is used for constructing a sparse recovery model containing phase error correction based on a low-rank and sparsity principle, wherein the sparse recovery model is adaptive to two-dimensional compressed sampling and is provided with an inverse synthetic aperture radar echo signal with phase distortion; And the inverse synthetic aperture radar image output module is used for solving the sparse recovery model based on a unified alternate direction multiplier method frame so as to finish sparse recovery and phase error correction of the two-dimensional compressed sampling signal and output an inverse synthetic aperture radar image.
13. The inverse synthetic aperture radar imaging system with phase distortion and two-dimensional compressed sampling of claim 12, wherein the sparse recovery model building module comprises: A signal model matrix definition unit for defining a matrix form of an inverse synthetic aperture radar signal model having fully sampled measured values; The signal model matrix downsampling unit is used for performing two-dimensional compressive sampling operation on the matrix form of the inverse synthetic aperture radar signal model to obtain a downsampled signal model; A signal model matrix rewriting unit, configured to rewrite the downsampled signal model because the phase error matrix is a diagonal matrix; an imaging problem definition unit for defining an inverse synthetic aperture radar imaging problem with low rank and sparsity constraint for radar data downsampled in two dimensions and having phase distortion.
14. The inverse synthetic aperture radar imaging system with phase distortion and two-dimensional compressed sampling of claim 12, wherein the inverse synthetic aperture radar image output module comprises: an augmented lagrangian function construction unit for constructing an augmented lagrangian function; and the alternate direction multiplier method solving unit is used for iteratively solving a plurality of minimization sub-problems by using an alternate direction multiplier method solver and outputting an inverse synthetic aperture radar image.
15. A terminal device comprising a memory, a processor and an inverse synthetic aperture radar imaging procedure with phase distortion and two-dimensional compressed sampling stored in the memory and executable on the processor, the processor implementing the steps of the inverse synthetic aperture radar imaging method with phase distortion and two-dimensional compressed sampling according to any of claims 1-11 when executing the inverse synthetic aperture radar imaging procedure with phase distortion and two-dimensional compressed sampling.
16. A computer readable storage medium, wherein the computer readable storage medium has stored thereon an inverse synthetic aperture radar imaging procedure with phase distortion and two-dimensional compressed sampling, which when executed by a processor, implements the steps of the inverse synthetic aperture radar imaging method with phase distortion and two-dimensional compressed sampling as claimed in any one of claims 1-11.

Description

Inverse synthetic aperture radar imaging method, system, terminal equipment and medium with phase distortion and two-dimensional compressed sampling Technical Field The invention relates to the technical field of radar imaging, in particular to an inverse synthetic aperture radar imaging method, an inverse synthetic aperture radar imaging system, terminal equipment and a medium with phase distortion and two-dimensional compressed sampling. Background The sparse reconstruction technology can effectively reconstruct signals under limited sampling and is widely applied to the fields of high-resolution radar imaging, medical imaging and the like. For an inverse synthetic Aperture Radar (ISAR, inverse Synthetic Aperture Radar), the existing sparse imaging technologies such as compressed sensing, matrix completion, mixing methods and the like only consider incoherence of compressed sampling, neglect the influence of phase errors, and the phase distortion can damage image sparsity and Radar data low rank property, so that imaging precision is reduced. Although there are phase correction techniques such as main/multiple scatterer autofocus, phase gradient autofocus (PGA, phase Gradient Autofocus), these techniques fail when directly processing down-sampled radar data due to lack of coherence in the pulses. Furthermore, the deep learning based hybrid approach, while alleviating parameter sensitivity, lacks generalization capability in processing new radar systems or new target data. Therefore, a method for combining two-dimensional downsampled signal sparse recovery and inverse synthetic aperture radar imaging phase error correction is needed to fill the gap in the prior art. Disclosure of Invention The invention aims to solve the technical problems that in the radar imaging field, the existing inverse synthetic aperture radar sparse imaging technology ignores the influence of phase errors, the existing phase correction technology fails to work on downsampled radar data, and the depth learning hybrid method has insufficient generalization capability, so that a clear inverse synthetic aperture radar image is difficult to generate under a two-dimensional compressed sampling and phase distortion scene. Therefore, an effective solution is needed to solve the above technical problems. In order to solve the technical problems, the technical scheme adopted by the invention is as follows: in a first aspect, the present invention provides a method of inverse synthetic aperture radar imaging with phase distortion and two-dimensional compressed sampling, the method comprising: Based on a low-rank and sparsity principle, constructing a sparse recovery model containing phase error correction, wherein the sparse recovery model is adaptive to an inverse synthetic aperture radar echo signal which is sampled in a two-dimensional compression mode and has phase distortion; based on a unified alternate direction multiplier method frame, solving the sparse recovery model to finish sparse recovery and phase error correction of the two-dimensional compressed sampling signal, and outputting an inverse synthetic aperture radar image. In one implementation, the constructing a sparse recovery model including phase error correction based on the low rank and sparsity principle includes: defining a matrix form of an inverse synthetic aperture radar signal model with fully sampled measurements; performing two-dimensional compressive sampling operation on the matrix form of the inverse synthetic aperture radar signal model to obtain a down-sampled signal model; Because the phase error matrix is a diagonal matrix, the downsampled signal model is rewritten; for radar data downsampled in two dimensions and with phase distortion, an inverse synthetic aperture radar imaging problem with low rank and sparsity constraints is defined. In one implementation, the matrix form of the inverse synthetic aperture radar signal model with fully sampled measurements is expressed as: Wherein, the The radar data representing the full sample is displayed,Representing an inverse synthetic aperture radar image,An additive white gaussian noise representing a full sample,A fourier matrix representing the distance dimension is presented,A fourier matrix representing the azimuth (transverse distance dimension),Representing the phase error matrix of the full sample,Representing the conjugate transpose operation. In one implementation, the two-dimensional compressive sampling operation is performed on the matrix form of the inverse synthetic aperture radar signal model, and the obtained down-sampled signal model is expressed as: Wherein, the Indicating a downsampling operation. In one implementation, since the phase error matrix is a diagonal matrix, the downsampled signal model is rewritten, expressed as: Wherein, the ,And is also provided with。 In one implementation, for two-dimensional downsampled and phase-distorted radar data, the inverse synthetic aperture radar imag