When the precise geometric rectification of TM imagery was made with the ground control points selected from topographic map in scale of 1:100000, the accuracy of half a pixel is high.

由1：10万地形图选取平面控制点对TM磁带进行精处理，平面定位精度为半个象元，精度较高；

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By means of GPS dummy network reference station positioning system, the ground control points for the calibration of remote sensing image were surveyed with the precision of centimeter level.

利用GPS虚拟网络参考站定位系统，以厘米级精度测定校正遥感图像的地面控制点。

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The slip surface is searched through moving the three geometric control points on the ground surface, the bottom of excavation and the surface at half of the height of the excavation, respectively.

通过分别移动基底、地表水平面和位于基坑高度一半处的水平面上的三个几何控制点，寻找到边坡最危险滑移面并计算出对应的稳定性安全系数。

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