Search

Wireless Local Area Network (WLAN) is a new information access platform which can be used to achieve positioning, monitoring and tracking in wide area. Self-positioned of the network node is the basis and prerequisite for most applications, although the current popular WiFi positioning technology is a position solution for WLAN series standard (IEEE802.11). In this paper, based on the principle of satellite navigation and positioning with wireless sensor networks, the new method of combining GPS and WiFi networks is put forward to achieve seamless positioning and navigation. And the potential problems of existed technology are conducted in-depth discussion by summing up the seamlessly, current location and navigation technology, as well as analyzing existed problems and trends. Finally, the WiFi network assisted GPS positioning algorithm is analyzed in detail.

Technological principle of EDSS and its architecture are introduced in this paper. In proposed EDSS, the four technologies, i.e. GPS, GIS, RS and ES are integrated to provide decision support for environment problem. The system model based on spatial information technology is elaborated on. The integration hierarchical structure of EDSS is also proposed and the conclusion is given in the final

The basic components of location based service (LBS) is introduced in this paper. It is composed of client, network and server. According to the work flow of LBS system, LBS service hierarchical architecture is elaborated on based spatial information Integration. Five levels architecture is described in detail and around 10 primary functions are analyzed also. Finally the application mode of LBS is proposed.

By introducing spatial information technology (SIT), including remote sensing, geographic information system (GIS), satellite navigation system, etc., the principals and methodologies of traffic information collection and management based on SIT were discussed in this paper. The analysis and fusion of all the available information by the support of GIS was described, and the Traffic Information Management System (TIMS) was designed and developed, which has many features such as friendly interface, easy operation and versatile functions. The system can be widely applied to traffic control, vehicle guidance and dispatching, route planning and infrastructure construction.

Satellite positioning technology has been widely used in all kinds of military and civil land, marine, space and aeronautical target positioning tasks, navigation activities and accurate surveying measurements since 90s in the last century due to its advantage in providing all weather, real-time, three dimensional and high precision positioning information, as well as speed and accurate timing information. This paper briefly reviews the development of the global satellite positioning and navigation technologies including the basic information of China's "Plough navigation system", introduces the history of satellite positioning technology and its major application fields. The paper also gives an account of the authors' vision for the application and prospect of the satellite positioning technologies in China, and approaches the tactics and stresses of the satellite positioning technology's application and its industrialization future in China.