由北京三足通讯技术公司研制的VTS车辆定位跟踪系统,主要用于交通管理,其技术已达到世界领先水平。与GPS(全球定位系统)相比,VTS具有精度高、系统容量火的优点。据悉,任何一辆配有该装置的机动车,只要在主控中心50公里半径范围内,无论是地下通道或茂密丛林,主控中心的电子地图都将准确地显示其位置,系统定位误差在5米以内。可同时管理30万辆下的VTS定位系统,还可对固定用户群,如银行、储
With the use of techniques in nonlinear problems, the IDP (improved discrepancy principle) method has been proposed and applied to the optimal smooth factor (parameter y) in the inversion process of a
随着人们对空间位置重要性的认识，地理信息系统（ＧＩＳ）已得到广泛地应用。本文对ＥＳＲＩ公司的组件式地理信息系统（ＧＩＳ）软件ＭａｐＯｂｊｅｃｔ（以下简称ＭＯ）中不同的符号绘制手段进行了介绍和比较。在此基础上，提出了一种基于组件的参数化方法来地绘制形式多样的自定义符号。并对ＧＩＳ中符号绘制技术的发展前景进行了展望。
A model of estimating the global positioning system (GPS) instrumental biases and the methods to calculate the relative instrumental biases of satellite and receiver are presented. The calculated resu
The uplift of the Tibetan Plateau has been monitored by the FG5 absolute gravimeter, whose observing accuracy is as high as 1×10-8m/s2. The analysis of the gravity observation results at the Lhasa sta
The problem of crustal movement in the Qing-hai-Tibetan Plateau is a hotstopic of the present-day international geodetic world. GPS observations in 1993, 1995 and 1997 are used to survey the three-dim