FORMOSAT-3/COSMIC science mission update

The FORMOSAT-3/COSMIC mission is a microsatellite mission for weather forecast, climate monitoring, and atmospheric, ionospheric and geodesy research. This mission is a collaborative Taiwan-USA science experiment to deploy a constellation of six microsatellites in low Earth orbits. The mission life is 2 years with a goal of 5 years. The final mission orbit has an altitude of 750–800 km. Each satellite consists of three science payloads: global positioning system (GPS) occultation experiment (GOX) payload, tiny ionospheric photometer (TIP) and tri-band beacon (TBB). The GOX will collect the GPS signals for the study on atmosphere, ionosphere, and geodesy. The TIP and TBB can provide the electron distribution information for ionospheric research. The deployment of the FORMOSAT-3 constellation and the resulting influence on the occultation sounding distributions are reported. Details are also given on GOX, TIP, and TBB payload operations and the contributions of the Taiwan Science Team.     

Interannual variability of low-degree gravitational change, 1980–2002

Time variations in the Earths gravity field at periods longer than 1 year, for degree-two spherical harmonics, C₂₁, S₂₁, and C₂₀, are estimated from accurately measured Earth rotational variations. These are compared with predictions of atmospheric, oceanic, and hydrologic models, and with independent satellite laser ranging (SLR) results. There is remarkably good agreement between Earth rotation and model predictions of C₂₁ and S₂₁ over a 22-year period. After decadal signals are removed, Earth-rotation-derived interannual C₂₀ variations are dominated by a strong oscillation of period about 5.6 years, probably due to uncertainties in wind and ocean current estimates. The model-predicted C₂₀ agrees reasonably well with SLR observations during the 22-year period, with the exception of the recent anomaly since 1997/1998.     

当前国家电子政务建设的思路

各位来宾,女士们、先生们:上午好!国土资源信息化建设研讨会今天在昆明隆重召开,我谨代表国务院信息化工作办公室王旭东主任,对此表示热烈祝贺!土地资源管理是国家非常重要的一项工作。土地审批,是宏观调控的重要闸门之一。搞好国土资源信息化建设,有利于合理利用土地资源,有利于国家宏观调控,有利于可持续发展,有利于构建和谐社会。国土资源信息化是国家电子政务和信息化建设的重要组成部分。在这里,我主要介绍一下国家整体上推进电子政务建设的一些想法和做法,供大家参考。     

基于ObjectARX的土地整理规划属性数据库系统设计与实现

论述土地整理规划属性数据库的设计思想和以ObjectARX为开发工具并基于AutoCAD图形数据库实现土地整理规划属性数据库的关键技术与实施方案。     

空间距离交会原理及应用

深入研究空间距离交会的基本原理,详细推导数据处理的主要公式,利用该公式可直接解算出任意投影面上的平面坐标和高程。结合工程实例,验证该方法的正确性和实用性,并讨论该方法在实际应用中的注意事项。     

Implementation of OGC web map service based on web service

OGC Web Map Service is one kind of OGC Portrayal Services belongs to OGC Web Service model and it provides multi-platform interoperability of spatial data set. This paper presents a method for implementing OGC Web Map Service based on Web Service technique and introduces the detailed process.     

用Voronoi方法为MapInfo扩展拓扑功能

分析了Voronoi图在表达邻近关系方面的特性,提出了用Voronoi方法为MapInfo建立动态邻近关系并扩展拓扑功能的方法。     

航空遥感稳定平台的模型参考自适应控制

针对航空遥感惯性稳定平台中所受到的不平衡力矩等所引起的成像载荷不稳定导致无法获取高分辨率遥感数据的问题,提出了在平台控制系统中应用基于模型参考的自适应比例-积分-微分控制方法。根据需求设计出参考模型,将参考系统输出与实际系统输出之间的误差输入到自适应PID调节器,实时调整PID参数,对误差进行实时校正,以达到抑制不平衡力矩扰动、提高稳定平台稳定精度的目的。对所提出的模型参考自适应控制方法进行了仿真验证,结果表明:相对传统PID方法,模型参考自适应控制器对偏心力矩等主要干扰具有很好的抑制作用,系统输出能够很好地跟踪姿态变化,系统稳定精度得到显著提高。     

网点印刷颜色再现物理模型

本文在讨论网点印刷呈色机理的基础上，提出四色版印刷时，用概率统计中的回归分析方法，修正Ｎｅｕｇｅｂａｕｅｒ方程，建立颜色再现物理模型。     

地图出版系统在地图复制中的应用

针对常规地图复制存在的问题，现在有一种新的地图复制技术和设备－地图出版系统。本文着重介绍该系统应用于地图复制过程的原理、方法和特点。