In this paper,several methods of the synchronization satellite positioning with the second pulse in TV-signals transmmitted by communication satellite are introduced,and calculation methods about PDOP in each positioning model are given.
给出了在各种观测方法中,地面测站与同步卫星所构成的几何图形强度因子的计算公式。
For the CAD drawings largely used in measuring and mapping work,the method is studied for quick conversion from DLG to DEM data with VC+ OPENGL software.
针对目前测绘行业中大量应用的CAD图形进行研究,在VC+OPENGL平台下实现了从DLG到DEM数据的快速转换方法,在DEM的基础上进行三维可视化,并解决了CAD矢量数据难以处理的体积计算、坡度计算等技术难题。