供平面变形观测用的弦线光机系统

工程建筑中经常需要布设能保证以足够精发对工艺设备的轴线进行放样的测量控制网。平面控制网的测量标志可能会埋没在将会产生变形的接础上。     

t-GIS and environmental dynamic models

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｏｄａｙｉｔｓｅｅｍｓｔｈａｔｐｅｏｐｌｅ’ｓｉｎｔｅｒｅｓｔａｎｄａｔｔｅｎ ｔｉｏｎｔｏＧＩＳｍａｉｎｌｙｆｏｃｕｓｏｎｔｈｅａｓｐｅｃｔｏｆｓｐａｔｉａｌａｔ ｔｒｉｂｕｔｅｓｏｆｇｅｏｇｒａｐｈｉｃｉｎｆｏｒｍａｔｉｏｎ ,ｎｏｔｓｕｆｆｉｃｉｅｎｔｌｙｏｎｔｉｍｅｆａｃｔｏｒ .Ｔｈｉｓｉｓａｎｅｒｒｏｎｅｏｕｓｔｅｎｄｅｎｃｙ ,ａｎｄｉｔｗｉｌｌｂｅｄｉｓａｄｖａｎｔａｇｅｏｕｓｔｏｔｈｅｂａｌａｎｃｅｄｄｅｖｅｌｏｐ ｍｅｎｔｏｆＧＩＳｗｈｅｎｅｘｐｌａｉｎｉ…     

Research on the security of national geospatial data clearinghouse based on ASP

1　ＩｎｔｒｏｄｕｃｔｉｏｎＮｅｅｄｌｅｓｓｔｏｓａｙ ,ｉｔｉｓｖｅｒｙｉｍｐｏｒｔａｎｔｆｏｒｍｏｓｔＧＩＳｕｓｅｒｓｔｏａｃｑｕｉｒｅａｎｄｉｎｔｅｇｒａｔｅｔｈｅｇｅｏｓｐａｔｉａｌｉｎｆｏｒ ｍａｔｉｏｎｆｒｏｍｖａｒｉｏｕｓｄｉｓｔｒｉｃｔｓ.Ｈｏｗｅｖｅｒ ,ｔｈｅｃｕｒｒｅｎｔｓｉｔｕａｔｉｏｎｏｆｇｅｏｓｐａｔｉａｌｉｎｆｏｒｍａｔｉｏｎｐｒｏｄｕｃｔｉｏｎａｎｄｄｉｓｓｅｍｉｎａｔｉｏｎｉｎｔｈｅｗｏｒｌｄｉｓｓｔｉｌｌｕｎｓａｔｉｓｆａｃｔｏｒｙ .Ｏｎｏｎｅｈａｎｄ ,ｕｓｅｒｓｄ…     

机载GPS自适应天线阵的测量结果

共形安装的机载GPS自适应天线阵的性能会受到阵列单元和飞机机身之间相互作用的影响。本文将介绍安装在比例为1：8的F－16飞机模型机身上的7单元微带贴片天线自适应阵列的设计和测量结果，以便评估这种天线阵与飞机间的相互作用及其在将多部宽带干扰机调零时对阵列性能的影响。自适应天线阵工作在12.6GHz的频率上，带宽为160MHz，分别是GPS L1频率和带宽的8倍。所有7个单元的远场天线方向图均在近场天线范围内的成比例频段上作了测量。为了更好地了解机体对天线方向图的影响，我们还将对隔离微带贴片单元测出的方向图与根据OSU－NEWAIR程序（code)计算出的天线方向图作了比较，OSU－NEWAIR程序使用均匀衍射理论来分析天线与机身间的相互作用。比较的结果表明，测量得的方向图和计算出的方向图之间具有良好的一致性。从这些缩比模型测量中收集的数据正在用来测试MITRE（麻省理工学院研究小组）开发的时空自适应调零算法在多部宽带干扰机相对飞机不同取向时的有效性。为了证明这种阵列在有两部窄带干扰机时使用简化直接矩阵求逆算法的调零能力，我们还进行了一些测量。测出的自适应阵列方向性图与理论上的预测十分吻合。文章还阐明了缩比模型测试的优点，以验证机载自适应阵列的调零性能。     

三维地籍

1.前言 在主要城市中心(特别是商业区),土地利用率如此之高,以至于空间上各楼层的用途都不相同。因此,目前所采用的二维地籍已不能满足实际要求。现有的三维情况的例子有: ·楼顶建筑 ·地上和地下的基础设施 ·日益增多的电缆和管道(受私有化进程影响,电缆和管道所有者的数量正越来越     

Similar single-difference model and its algorithm for solving GPS monitoring deformation directly at single epoch

A new similar singledifference mathematical model ( SS-DM) and its corresponding algorithm are advanced to solve the deformation of monitoring point directly in single epoch. The method for building the SSDM is introduced in detail, and the main error sources affecting the accuracy of deformation measurement are analyzed briefly, and the basic algorithm and steps of solving the deformation are discussed. In order to validate the correctness and the accuracy of the similar single-difference model, the test with five dual frequency receivers is carried out on a slideway which moved in plane in Feb. 2001. In the test, five sessions are observed. The numerical results of test data show that the advanced model is correct.     

SVLBI用于大地测量的卫星轨道及其跟踪网设计

SVLBI （space very long baseline interferometry） has some important potential applications in geodesy and geodynamics, for which one of the most difficult tasks is to precisely determine the orbit of an SVLBI satellite. This work studies several technologies that will possibly be able to determine the orbit of a space VLBI satellite. Then, according to the types and charac- teristics of the satellite and the requirements for geodetic study and the geometry of the GNSS （GPS, GALILEO） satellite to track the space VLBI satellite, the six Keplerian elements of the SVLBI satellite （TEST-SVLBI） are determined. A program is designed to analyze the coverage area of space of different altitudes by the stations of the network, with which the tracking network of TEST-SVLBI is designed. The efficiency of tracking TEST-SVLBI by the network is studied, and the results are presented.     

改进的能量守恒方法及其在CHAMP重力场恢复中的应用

An efficient method for gravity field determination from CHAMP orbits and accelerometer data is referred to as the energy balance approach. A new CHAMP gravity field recovery strategy based on the improved energy balance approach IS developed in this paper. The method simultaneously solves the spherical harmonic coefficients, daily Integration constant, scale and bias parameters. Two 60 degree and order gravitational potential models, XISM-CHAMPO1S from the classical energy balance approach, and XISM-CHAMPO2S from the improved energy balance, are determined using about one year＇s worth of CHAMP kinematic orbits from TUM and accelerometer data from GFZ. Comparisons among XISM-CHAMPO1S, XISM-CHAMPO2S, EIGEN-CGO3C, EIGEN-CHAMPO3S, EIGEN2, ENIGNIS and EGM96 are made. The results show that the XISM-CHAMPO2S model is more accurate than EGM96, EIGENIS, EIGEN2 and XISM-CHAMPO1S at the same degree and order, and has almost the same accuracy as EIGEN-CHAMPO3S.     

圣诞老人是中国人——为什么中国经济在崛起而美国在衰退

之所以说圣诞老人是中国人原因是每次圣诞节清晨当人们打开收到的礼物后,我总是习惯性地看一看这些礼物的产地,但结果几乎总是相同的:大约有70%的礼品产地是中国。而我自己家庭的情况对于整个国家来讲也具有一定的代表性。先从玩具谈起。从芭比娃娃到游戏机,美国出售