沙漠地区旁折光影响的规律

THE LAW OF THE SIDE-REFRACTION INFLUENCE IN DESERT REGIONS

本文根据我国西北地区,塔里木和柴达木两盆地沙漠地区所布设的一等三角锁环资料统计分析,沙漠地区旁折光属于同性折光场影响,它使得沿沙漠地区布设的一等三角锁系全向沙漠中心偏转。沙漠地区旁折光对三角锁系的方位角条件及基线条件常数项的影响表现为系统性误差。而一等三角锁系的图形条件和极条件常数项则不受旁折光影响。按照统计分布检验结果,三角形闭合差仍为随机误差,并服从正态分布,而三角锁系的观测误差却不服从正态分布。本文对沙滇地区的布设的控制网平差处理以及为提高三角锁系的精度均有一定的意义。

According to the statistic analysis of the data of first-class triangulation chains laid in the desert regions of the Tallim Basin and Qaidam Basin in the northwestward of our country, the side-refraction influence in desert regions is the same character istic refraction field influence. It makes all the first-class triangulation chains laid in desert regions incline to the centre of the desert regions. The influence of the side-refraction in desert regions on the absolute terms of the azimuth conditions and base-line conditions of triangulation chains is expressed as systematic errors. The side-refraction doesn't affect the absolute terms of the figure conditions and pole conditions of first-class triangulation chains. According to the test result of statistic distribution, the triangle closure error is random error and obeys the Normal Distribution, however the error of survey of triangulation chains doesn't obey the Normal Distribution. The paper has certain significance to layout, survey and adjustment process of the control network and also for improving the accuracy of triangulation chains in desert regions.