Microwave Staring Correlated Imaging Method Based on Steady Radiation Fields Sequence

Abstract

Microwave Staring Correlated Imaging (MSCI) is a newly proposed computational high-resolution imaging technique. The imaging performance of MSCI with the existence of modeling errors depends on the properties of the imaging matrix and the relative perturbation error resulted from existing errors. In conventional transient-radiation-fields-based MSCI, which is commonly accomplished by utilizing random frequency-hopping (FH) waveforms, the multiple transmitters should be controlled individually and simultaneously. System complexity and control difficulty are hence increased, and various types of modeling errors are introduced as well. The computation accuracy of radiation fields is heavily worsened by the modeling errors, and the transient effect makes it hard to take direct and high-precision measurements of the radiation fields and calibrate the modeling errors with the measuring result. To simplify the system complexity and reduce error sources, in this paper, steady-radiation-fields-sequence-based MSCI (SRFS-MSCI) method is proposed. The multiple transmitters are excited with coherent signals at the same observation moment, with the signal frequency varying in the whole frequency band during the imaging process. By elaborately designing the array configuration and the amplitude and phase sequences of the coherent transmitters, the SRFS-MSCI is thus implemented. Comparing the system architecture of the proposed SRFS-MSCI with the conventional random FH-based MSCI, it can be found that the proposed method significantly reduces the number of baseband modules and simplifies the system architecture and control logic, which contributes to reducing error sources such as baseband synchronization errors and decreasing deterioration caused by error cascade. To further optimize the design parameters in the proposed SRFS-MSCI system, the Simulated Annealing (SA) algorithm is utilized to optimize the amplitude sequences, the phase sequences, and the antenna positions individually and jointly. Numerical imaging experiments and real-world imaging experiment demonstrate the effectiveness of the proposed SRFS-MSCI method that recognizable high-resolution recovery results are obtained with simplified system structure and optimized system parameters.

Waveform design of radar coincidence imaging radiation field based on image entropy

“…This is primarily attributed to the constraint on energy dissipation, ensuring that energy is predominantly confined within the corresponding grids. When using sequence (4), there is a reduction in image entropy; however, due to the lack of consideration for target characteristics, the imaging performance is inferior to that obtained by sequence (5). Imaging performance using sequence (2) and sequence (3) does not improve.…”

“…Therefore, each resolution element has MN scattering intensity values under MN observation angles. Scattering intensity values are generated by Equation (5).…”

“…The influence of the condition number of the Gram matrix on the imaging performance is analyzed in [4] and the sensitivity of imaging to errors is reduced. We learn the orthogonality of radiation field cannot be directly obtained by the orthogonality of radiation source parameters [5].…”

Bistatic Radar Cooperative Imaging Based on Complementary Random Waveform

“…Moreover, the missile-borne radar usually works in complex electromagnetic environments with a large number of jammers. In order to improve the detection performance, the missile-borne radar usually adopts a random frequency-hopping signal with excellent anti-jamming performance [10][11][12][13]. Therefore, based on the bistatic radar detection framework and the random frequency-hopping signal system, this paper studies the bistatic radar cooperative imaging method.…”

“…Finally, a band fusion algorithm is designed to achieve two-dimensional imaging of the target. The radar imaging method studied in this paper has the advantages of the bistatic radar system and a random frequency-hopping signal [3][4][5][10][11][12][13]. It improves the detection performance and realizes the efficient estimation of target velocity, which lays a foundation for the future study of missile-borne radar collaborative detection imaging.…”