Research on data collection and database update of GIS based on GPS technology

Data is the core and emphasis of geographical information system (GIS). The operations such as information storage, management, inquiry, analysis and description all depend on data. Data collection is the basic work of GIS construction. Conventional methods can´t satisfy the need of GIS development with some disadvantages such as low digital degree, high cost and long time consuming. Global Positioning System (GPS) provides three-dimension position, velocity and time information about any point on the earth with high precision, whole-day and continuous properties by receiving radio signals from satellites. GPS as one of the most mature orientation technologies has gradually become one of the most important data resources of GIS. This paper focuses on two aspects. The first one is the technology and method of GIS data collection based on Global Positioning System. GPS dynamic data communication, position data process method and data transformation technology is discussed in detail with resolving methods and flow charts. The second one is the technology and method of GIS database update. The weighted average method of update which considers the original GIS position data as one kind of measurement and the GPS position data as another kind of measurement computes the average of these two kinds of measurements to get the new position information. And these two kinds of measurement are considered with different weights. The study is undertaken on Zhalong Wetland in Qiqihaer City China and Malan River in Dalian City China. The investigation results prove that the data collection and database update of GIS based on GPS technology can orient changed areas rapidly and make the local database update more convenient and flexible. It is helpful in trend prediction of wetland for the sustainable development of regional economy and has some significance in wetland dynamic analysis, protection and exploiture.