“…To get a higher-accuracy and higher-fidelity DEM, it is necessary to do some experiments recovered by different parameter estimation algorithms, and make comparisons about the results. Addressing the problem of distortion, the LS is one of the most widely used algorithms (Shyu, 2009;Wang, Qiu, & Cheng, 2011), whose principle is that minimizing the sum of squared residuals (shown in Figure 2) of the differences between the distorted values and recovered values to get the parameters of model. However, the LS cannot avoid abnormal data (DEM often presents in some mutations of elevation), the RANSAC is taken to compare with the LS, for it can reduce the interference of anomalous data and is widely used to improve the data accuracy (Schnabel, Wahl, & Klein, 2007;Raguram, 2008;Zhou, Zhu, & Li, 2011).…”