为了研究沙漠、草地等具有连续分布特点的自然地物对星载激光测高仪回波特性的影响，以菲涅耳衍射理论为基础，建立连续地面物理模型，采用网格划分的方法，对地面平均高度以及地面高度均方差对回波形状、功率和脉冲宽度等特性的影响进行了数值模拟研究。结果表明，若地面高度均方差一定，地面平均高度的变化不会引起脉冲回波信号的变化，而地面高度均方差的变化会直接导致回波信号的变化。

According to the theory of Fresnel diffraction, a continuous land model was established for natural terrain like desert and grass land, a method of gridding partition was developed to simulate the effect of average surficial height and height mean square error on the properties of return signal, including waveform, power and pulse width. The results show that height mean square error determines the properties of return signal, while the change of terrain mean height cause no difference in return signal in the case of fixed height mean square error.