Automatic registered back‐projection approach based on object orientation for airborne repeat‐track interferometric SAR

Xiang

et al. 2021

IEEE Access

The interferometric synthetic aperture radar (InSAR) elevation inversion method based on the backprojection (BP) imaging model simplifies the interferometric processing chain where image registration and phase unwrapping are not required. Meanwhile, BP algorithm is suitable for radar with different imaging modes and geometry. However, the existing calibration methods are all aimed at traditional InSAR which adopts frequency domain imaging algorithm, but the calibration method for backprojection InSAR elevation inversion model has not been published. In this paper, we propose a novel InSAR calibration method which combines Fast Fourier Transform (FFT) estimation method with sensitivity equation method based on backprojection imaging model. FFT is used to process the interferometric phase which has removed the terrain phase of external digital elevation model (DEM) under BP imaging, and the estimation of interferometric parameters is realized through the phase fringe frequency. In the calibration method based on sensitivity equations, the deviations of interferometric parameters are calculated by solving sensitivity equations according to the three-dimensional information of ground control points. FFT estimation method not only generates the initial baseline parameters for sensitivity equation method, which is conducive to obtaining the global optimal solution, but also separates the calibration of phase offset and baseline parameters, which makes it possible to minimize the condition number of sensitivity matrix in sensitivity equation method. Finally, we obtain the calibrated interferometric parameters through iteration of sensitivity equation method and realize high accuracy DEM inversion. Both simulation experiment and airborne dualantenna InSAR data processing are performed to verify the effectiveness of this method.INDEX TERMS backprojection imaging model, FFT baseline estimation, InSAR calibration, sensitivity equations.

Section: Figure 4 Schematic Diagram Of Local Optimum Of Sensitivity Equation Methodsmentioning

confidence: 99%

Section: Interferometric Parameter Estimation Based On Fast Fourier Transformmentioning

confidence: 99%

Section: A Simulation Experimentsmentioning

confidence: 99%

Section: B Airborne Dual-antenna Insar Data Processmentioning

confidence: 99%

See 2 more Smart Citations

A Novel Airborne Dual-Antenna InSAR Calibration Method for Backprojection Imaging Model

Xiang

et al. 2021

IEEE Access

“…However, the repeat-pass InSAR has problems such as its temporal baseline, non-parallel flight route and real-time varying attitude and position [ 19 , 20 ], which makes the coherence of repeat-pass interferometry image pairs very low. Besides, light and small carrier platforms installed with FMCW SAR are more sensitive to atmospheric disturbances.…”

Section: Introductionmentioning

confidence: 99%

A Coherence Improvement Method Based on Sub-Aperture InSAR for Human Activity Detection

Xiang

et al. 2021

Sensors

Human activity detection plays an important role in social security monitoring. Since human activity is very weak, it is necessary to employ the repeat-pass Interferometric Synthetic Aperture Radar (InSAR) technique to detect the potential activity between two data acquisitions; a high level of coherence is required for detection. With the object of detecting human activity of interest, this paper presents a coherence improvement approach based on sub-aperture InSAR for human activity detection. Different sub-apertures contain different scattering information of the target, as they represent the backscatter of the target from a different range of angles. Integrating corresponding sub-aperture interferometric results can improve the coherence between two complex images compared to the entire synthetic aperture, as well as removing a little disturbance in some circumstances. To validate the method presented in this paper, the actual airborne Ka-band frequency modulated continuous wave (FMCW) InSAR data acquired by the Aerospace Information Research Institute, Chinese Academy of Sciences (AIRCAS) are utilized. The experimental results demonstrate that the proposed method can effectively improve the coherence between two complex SAR images and can validly detect human activity of interest.

High-Resolution Synthetic Aperture Imaging Algorithm for Terahertz

2023

J. Phys.: Conf. Ser.

The reconstruction and recovery of targets in the terahertz band has always been a direction for the improvement of synthetic aperture radar imaging algorithms. In order to improve the imaging resolution of the target, the scattering principle of electromagnetic waves to the target is analyzed. Through model establishment and formula derivation, the propagation process between the electromagnetic wave and the target is obtained, and the simulation and experiment verify that the corresponding algorithm can greatly improve the accuracy of target recovery.