Based on the two-layer media imaging problem that high-resolution imaging glacier penetrating radar (HRI-GPR) system has

this paper analyzes the spatial geometry and studies a modified nonlinear chirp scaling algorithm which can compensate the refraction effects and the propagation velocity changes in different medium automatically.This algorithm also can improve the focusing feature of the scatter.According to the model of echo signal

the phase compensation factors and realized steps of algorithm are given.Raw data of the radar is simulated

and image is achieved by using the algorithm proposed.The imaging quality is compared with theoretical value.Experimental results demonstrate the validity of the proposed algorithm.