Due to the frequent mining activity and increasing mine geological disasters in our country

the long term dynamical monitoring and analysis of the mining area are of great importance to prevent the potential geological damage in mining area. The Permanent Scatterer Interferometric Synthetic Aperture Radar（PSIn SAR）

a newly developed ground deformation monitoring technique

which may not be influenced greatly by the spatial and temporal deccorelation

has been widely applied in study on regional displacement

including the deformation of urban area

terrain area and mining area. During the step of spatial unwrapping in PSIn SAR algorithm

stable points or external known GPS points are necessary. The procedure of selecting the reference stable points is obviously uncertain and the external GPS data is difficult to obtain. Due to the shortcomings of traditional spatial unwrapping in PSIn SAR algorithm

a new method of spatial unwrapping based on periodic function is developed. Since Corner Reflector（CR） point can be installed easily

which can be applied in the area without external constrained data（such as GPS data） and avoid the uncertainty of choosing reference point in the PS parametric adjustment network

the subsidence rates calculated on CR points are used as constraints for PS network while the spatial unwrapping is performed using the parametric adjustment method. With the improved method

the PSIn SAR is applied in the inversion of time series ground deformation in mining area.With 14 ALOS PALSAR images from February 2007 to February 2010

the deformation inversion experiment is carried out. The colliery dense distribution area

around Baisha reservoir in Henan province

is chosen as the study area in the experiment. 6546 PS points except CR points are detected during the experiments. The linear velocities calculated out through traditional spatial unwrapping method are compared to that of the developed method. The algorithm achieves the integration of CR data and PSIn SAR algorithm for the first time. The authors succeed to inverse the time series of subsidence from February in 2007 to February in 2010

using the periodic function to simulate the linear and nonlinear components of the deformation. The results show that there appears obviously time series subsidence around the reservoir

with the max value over 10 cm in the colliery distribution area

due to mining activities. The subsidence mainly performs to be linear subsidence. The nonlinear subsidence only appears to be a little obvious in the northeast of the reservoir. In order to validate the result of the experiment

deformation monitoring with leveling was also carried out in the area. With comparison to the deformation result of leveling

the accuracy of ± 2.1mm is calculated.It can be concluded from the good accordance that the method has the following advantages:（1） CR point can be installed easily

hence we can choose the study area freely

which can be applied in the area without external constrained data（such as GPS data）;（2） CR Point can be taken as constraining data for the spatial unwrapping of PS network and increase the redundancy number of parametric adjustment model which can make the solutions more stable;（3） Corner reflectors have high reflectivity which can be identified easily on the SAR image

thus the inaccuracy within the step of coordinate transformation can be avoided and the accuracy of the solutions can be improved.（4） It can avoid the uncertainty of choosing reference point in the PS parametric adjustment network.