Research On Land Use Changing Investigation Data Collection System Based On GPS And GIS

With the rapid development of economy, the cultivated land is reducing, the forest land is withering, the land is degenerating, and the ecology is worsening in our country. The situation is so stern that the departments of land resources must learn the changing pattern of farmlands in towns and in the countryside very accurately and in time. Then we can provide the foundation for the sustained development of agriculture and for the establishment of police to protect the farmlands. But the traditional method of surveying land has some shortening, for example, it is very difficult to obtain the boundary coordinately; mapping is very difficult and needs long time; and man' s operation is at random.The purpose of this paper is to study and explore the embedded data-collecting system of land use changing investigation based on Person Digital Assistant and Global Positioning System OEM, by using the rapid-development laptop and satellite positioning technique and taking the characteristics of data-collecting into account. According to technical requirement of land use changing investigation, this system involves two parts: PC and laptop. Laptops are used by outdoors workers so that the procedure of land measurement can be visual and intellectual. PC is used to calculate the pseudo-range difference and manage the data of land use changing investigation in combination with the data received by the PDA. This paper mainly studies the following:1. This paper summarizes systematically the development and the present situation of land use changing investigation, it discusses the purpose and significances of research, and it analyzes the tendency of land use changing investigation.2. This paper describes systematically the precision requirement of space positioning and clarifies the common space positioning techniques, especially the method of pseudo-range smoothing technique by carrier phase, its mathematical model, and relative software system. On this basis, given the environmental influence on GPS observation, this paper put forward integrated positioning model.3. Through GPS pseudo-range smoothing experiment by carrier phase, the paper testifies if the precision of space positioning technique can satisfy the requirement of land use changing investigation.4. The paper designs some software for land use changing investigation, such as data-collecting software, data-processing software and result-management software. The data-collecting mould is developed in Windows CE operation system; the data processing software first changes the original observational data into the standard format (RINEX), then this software usesMicrosoft Visual Basic 6. 0 to form the observational document of pseudo-range differential position and to calculate; finally this software utilizes MapX and Visual Basic environment programming to analyze and manage the result of land use changing investigation and to store the designed software in the experiments of land use changing investigation. In the end, the paper concludes the technique with living examples and foresees its prospect.