Iterative multi-baseline high-precision 4-FFT phase unwrapping method

Abstract

The invention discloses an iterative multi-baseline high-precision 4-FFT phase unwrapping method. A 4-FFT phase unwrapping algorithm is introduced to multi-baseline phase unwrapping, the interferometric phase information of a solved baseline is enriched through interferometric phase obtained by other baselines from different perspectives, an iterative terminating condition is set, subtraction is carried out on the multi-baseline unwrapping phase and wrapping phase corresponding to the solved baseline, a principal value is taken, and an unwrapping error principal value is obtained; the unwrapping error principal value is subjected to 4-FFT phase unwrapping to obtain an unwrapping error real value; iterative compensation is finally carried out on the multi-baseline 4-FFT unwrapping phase continuously, unwrapping errors are reduced, whether the iterative terminating condition is met is judged, the operation is terminated until to reach the terminating condition, and final unwrapping phaseis obtained. The phase stacking problem of a single-baseline 4-FFT phase unwrapping algorithm can be solved, and higher interferometric phase unwrapping precision can be acquired.

Description

technical field [0001] The invention belongs to the technical field of radar, in particular to the technical field of phase unwrapping in interferometric synthetic aperture radar (InSAR) elevation surveying and mapping. Background technique [0002] Interferometric Synthetic Aperture Radar (InSAR) is an extension of Synthetic Aperture Radar (SAR) imaging technology. It mainly uses more than two antennas or multiple passes to observe the same observation scene at different angles or at different time periods to obtain more than two SAR images. SAR image interferometric phase information, combined with the imaging geometric relationship to invert the terrain elevation information, thus realizing the remote sensing technology of high-precision terrain three-dimensional surveying and mapping. In the data processing flow of InSAR 3D imaging technology, it is first necessary to perform high-precision imaging processing on InSAR echo signals. The observation angles of the two anten...

AI Technical Summary

Problems solved by technology

Perform 4-FFT phase unwrapping on the main value of the unwrapping error to obtain the true value of the unwrapping error, and finally iteratively compensate the multi-baseline 4-FFT unwrapping phase to reduce the unwrapping error and judge whether the iteration termination condition is met, until When the termination condition is reached, the operation is ended to obtain the final unwrapping phase. This method solves the phase stacking problem of the single baseline 4-FFT phase unwrapping algorithm and achieves higher interferometric phase unwrapping accuracy.

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