This paper discusses the placement of Chinese annotation from point of view of graphics. Area Feature is classified as simple polygon, complex polygon and special polygon. For simple ones, annotations are placed along...This paper discusses the placement of Chinese annotation from point of view of graphics. Area Feature is classified as simple polygon, complex polygon and special polygon. For simple ones, annotations are placed along the longest edge. For complex ones, firstly the polygon are simplified according to close points, then the longest diagonal is gotten by comparing length, lastly, annotations are placed along long diagonal. For special ones, the polygon are partitioned into several parts by a certain rule for getting their sub\|diagonals, then their annotation are placed by means of the second.展开更多
This paper develops a WebGIS\|based GPS vehicle monitoring system with typical three\|tier application architecture of B/S pattern. It provides ordinary registered users with a valid and convenient means to get access...This paper develops a WebGIS\|based GPS vehicle monitoring system with typical three\|tier application architecture of B/S pattern. It provides ordinary registered users with a valid and convenient means to get access to real\|time GPS location information of certain moving vehicles at any place, and further offers a powerful tool for super users to manage user information and remotely monitor those vehicles and provide corresponding services timely if necessary. The system architecture, function modules, key technologies and application interfaces are given. Finally, the validity of our system is demonstrated in practical cases.展开更多
The new Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite image offers a large choice of opportunities for operational applications. The 1-km Advanced Very High Resolution Radiometer (AVHRR) image is not...The new Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite image offers a large choice of opportunities for operational applications. The 1-km Advanced Very High Resolution Radiometer (AVHRR) image is not suitable for retrieval of field level parameter and Landsat data are not frequent enough for monitoring changes in crop parameters during the critical crop growth periods.A methodology to map areas of paddy fields using MODIS,geographic information system (GIS) and global position system (GPS) is introduced in this paper. Training samples are selected and located with the help of GPS to provide maximal accuracy.A concept of assessing areas of potential cultivation of rice is suggested by means of GIS integration. By integration of MODIS with GIS and GPS technologies the actual areas of rice fields in 2002 have been mapped. The classification accuracy was 95.7% percent compared with the statistical data of the Agricultural Bureau of Zhejiang Province.展开更多
可视化方法可有效分析处理勘查设计的数据结果。传统公路勘查工作使用纸质化方式填写,存在多种问题,如测量精度不准确、时间长,导致勘查设计工作受到了影响。新信息技术的智能化发展改变了公路交通勘查方式,合理使用地理信息系统(Geogra...可视化方法可有效分析处理勘查设计的数据结果。传统公路勘查工作使用纸质化方式填写,存在多种问题,如测量精度不准确、时间长,导致勘查设计工作受到了影响。新信息技术的智能化发展改变了公路交通勘查方式,合理使用地理信息系统(Geographic Information System,GIS)与全球定位系统(Global Positioning System,GPS)智能化技术,可以快速获取地形原始数据勘查相关数据,健全道路勘查设计内容,实现智能化手段对公路设计过程的支持以及对路网构建与应用。展开更多
文摘This paper discusses the placement of Chinese annotation from point of view of graphics. Area Feature is classified as simple polygon, complex polygon and special polygon. For simple ones, annotations are placed along the longest edge. For complex ones, firstly the polygon are simplified according to close points, then the longest diagonal is gotten by comparing length, lastly, annotations are placed along long diagonal. For special ones, the polygon are partitioned into several parts by a certain rule for getting their sub\|diagonals, then their annotation are placed by means of the second.
文摘This paper develops a WebGIS\|based GPS vehicle monitoring system with typical three\|tier application architecture of B/S pattern. It provides ordinary registered users with a valid and convenient means to get access to real\|time GPS location information of certain moving vehicles at any place, and further offers a powerful tool for super users to manage user information and remotely monitor those vehicles and provide corresponding services timely if necessary. The system architecture, function modules, key technologies and application interfaces are given. Finally, the validity of our system is demonstrated in practical cases.
文摘The new Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite image offers a large choice of opportunities for operational applications. The 1-km Advanced Very High Resolution Radiometer (AVHRR) image is not suitable for retrieval of field level parameter and Landsat data are not frequent enough for monitoring changes in crop parameters during the critical crop growth periods.A methodology to map areas of paddy fields using MODIS,geographic information system (GIS) and global position system (GPS) is introduced in this paper. Training samples are selected and located with the help of GPS to provide maximal accuracy.A concept of assessing areas of potential cultivation of rice is suggested by means of GIS integration. By integration of MODIS with GIS and GPS technologies the actual areas of rice fields in 2002 have been mapped. The classification accuracy was 95.7% percent compared with the statistical data of the Agricultural Bureau of Zhejiang Province.
文摘可视化方法可有效分析处理勘查设计的数据结果。传统公路勘查工作使用纸质化方式填写,存在多种问题,如测量精度不准确、时间长,导致勘查设计工作受到了影响。新信息技术的智能化发展改变了公路交通勘查方式,合理使用地理信息系统(Geographic Information System,GIS)与全球定位系统(Global Positioning System,GPS)智能化技术,可以快速获取地形原始数据勘查相关数据,健全道路勘查设计内容,实现智能化手段对公路设计过程的支持以及对路网构建与应用。
