GPS在胶南市地理信息工程中的应用

在胶南市应用GPS建立三等平面控制网及高程拟合作业过程中，所采用的数据处理方法提高了平面精度和高程拟合精度。该GIS工程证实，应对平面网的起算点进行精度检测和保留三维无约束平差中精度较低的短基线。就高程拟合而言，应采用多种方案对已知GPS水准点进行各种精度检验，同时对所求点的拟合高程进行精度检验，以多种拟合方案所计算出的所求点拟合高程的均值作为最或然高程，计算每种拟合方案的所求点拟合高程中误差及拟合高程与最或然高程的最小差值和最大差值；然后，综合考虑所有精度检验结果，并从中找出一种最优拟合方案。

Application of GPS in Jiaonan Geographical Information System Engineer

During the period of establishing third grade plane controlling net and elevation fitting work by using GPS, plane precision and elevation fitting precision are promoted. It is proved that precision test of measuring point in plane net should be carried out and short reference line with low precision in three-dimensional un-forbidding adjusting error should be kept. As to elevation fitting, many methods should be used to test all precision in already known GPS level mark. At the same time, precision of fitting elevation of measured spots are tested. Regarding average value of fitting elevation of measured spots as most probable error, errors, smallest and biggest values of fitting elevation are measured, and regarding all precision testing results, the best fitting plan is chosed.