InSAR是一种极具潜力的新型空间大地测量方法，但它也有其固有的限制，特别是受到大气层延迟（对流层延迟、电离层延迟等）、卫星轨道误差、地表状况和时变去相关性等影响，很容易导致InSAR图像解释错误，而InSAR数据本身无法解决所存在的上述问题。而GPS可以精密定位，可以较为精确地确定电离层、对流层参数，是当前应用最广泛的一种空间大地测量手段。-InSAR is a potential new space geodetic methods, but it also has its inherent limitations. in particular by the delay in the atmosphere (troposphere delay, ionospheric delay, etc.), satellite orbit errors, Surface conditions and time-varying correlation to the impact of such very easily lead to wrong interpretation of InSAR image, InSAR data and by itself can not solve the above problems. GPS precision positioning can be more accurately determine the ionosphere, troposphere parameters, is the most widely used as a means of space geodesy.