湖北某市城区四等GPS控制网测量实践

Control Survey Practice with 4-grade GPS Net in a City of Hubei

介绍某山区城市四等GPS控制网的施测过程和测量效果。针对影响山区GPS测量的客观因素,分析主要误差来源,选择设计合适的网形,参考星历预报,GPS点环视图和基线长度,特别是现场反馈的测站信息,有选择变更观测时段长度甚至待定点位置可有效减弱山区交通、地形给GPS测量带来的不利因素,在保证精度的基础上,减少外业工作量、提高效率、降低成本。

The control survey practice with 4 - grade GPS in the mountainous city and the surveying effect are described. The sources of the survey error are analyzed based on the external factor of affecting the survey mountainous by using GPS. The outward workload and the cost are decreased, and the efficiency of work in the mean time is improved on basis of assuring the precision of survey results by means of the appropriate the net form selection and design, the ephemeris forecast reference, the spot annular map of GPS and the length of base line, especially the information of the spot survey feedback, selectively variation of the observation periods and the position of the unfixed spot to effectively decrease the disadvantageous factor of the landform and mountainous traffic to the survey of GPS.