Objectives Differential interferometric synthetic aperture radar(DInSAR) has been widely used in large-scale surface deformation monitoring. However, the surface deformation obtained from spaceborne synthetic aperture radar(SAR) data is easily affected by atmospheric noise, and the long revisit period leads to the incoherence. In order to effectively reduce these effects, we propose a method to monitor the deformation of highway slope by vehicle-borne InSAR system.
Methods Due to the orbit control of the vehicle-borne dual-antenna InSAR system, the spatial baseline of the interferometric pairs is close to zero.Therefore, when the DInSAR data with this system is used to extract the deformation information, it can avoid the flat phase, which greatly simplifies the differential interference processing process.
Results A certain area of Wuhan, Hubei Province is chosen as the experimental area. Seven corner reflectors are deployed in the test area to evaluate the accuracy of deformation information extracted using the vehicle-borne dual-antenna InSAR system.The deformation of seven reflectors is calculated by using the proposed method. The root mean square error of deformation between the real value and the calculated value is 2.206 mm.
Conclusions A deformation monitoring method of zero space baseline using the vehicle-borne dual-antenna InSAR system is proposed and verified in Wuhan city. The DInSAR method based on zero space baseline can avoid the process of the flat phase. At the same time, our system is small in size, and the design of the trajectory according to the actual needs is flexibly, which is very practical for small-scale highway slope deformation monitoring. Because of the small revisit period, the vehicle-borne InSAR Data will not produce phase error due to atmospheric delay, and the deformation measurement accuracy is high.