GBSAR has been widely used in landslides monitoring for its high precision in deformation monitoring and portable characteristic in natural environments. When monitor slides in mountainous areas, GBSAR cannot only work in positive mode, and its antennas may be directed to the target with a large squint angle. Unfortunately, normal range doppler imaging algorithm is not used well in such applications. Thus, a correction method of RD algorithm for SAR imaging with a squint angle has been proposed in the paper. Because the monitoring target may be far away from the view center of the GBSAR, echo of the target may be side lobe resided, when it is received by the radar's sensor. Simultaneously, distance between the sensor and imaging target changes with the azimuth time. Therefore, target in the SAR image would not be focused in one range bin if no range correction method was used. Thus, phase correction methods were used in the paper. The phase error was corrected in range domain and azimuth domain, respectively. It avoids 2D FFT processing. Thus, it may use few time and work. In this way, the GBSAR would have real time processing ability in the future. In the paper, a GBSAR was designed and used in slide monitoring applications in western mountains of Beijing. The experiment result shows that the system can measure target's micro deformation in mm levels with a high precision.
"Landslides Monitoring with a Squint Angle Based on GBSAR," Progress In Electromagnetics Research M,
Vol. 80, 13-22, 2019. doi:10.2528/PIERM19012202
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