Obtaining the change in surface elevation through satellite telemetry not only eliminates the need to go to the site, but also saves manpower and time, and can understand the trend and distribution of subsidence in a large area. Therefore, we should vigorously promote the evaluation to promote its applicability. INSAR interferometric measurement technology is currently the most promising. INSAR technology uses satellite microwave image data to quickly and accurately obtain the topographic variables of the study area after phase interference calculation and analysis. Its deformation detection potential can reach a common classification. It has been applied in seismology, volcanology, forestry, Research on ice and snow, land use, etc.

Synthetic Aperture Radar Interferometry (InSAR) is widely used in geodetic surveys due to its advantages of high resolution and common classification accuracy; Differential Synthetic Aperture Radar (D-InSAR) is a forward-looking development based on satellite radar echo coherence characteristics The permanent scatter synthetic aperture radar interferometry (PS-InSAR) can use natural permanent scattering points to effectively obtain surface deformation information, and obtain high-precision (mm-level) displacement information from the reflected signal.

The work of InSAR technology mainly includes the following six major items:

(1) Evaluation of the study area.

(2) Sorting, ordering and archiving of basic satellite image data.

(3) DInSAR calculation processing.

(4) PSI calculation processing.

(5) Verification of interferometric measurement results.

(6) Data fusion processing and analysis.