A Study On The Data Collection And Processing Methods Of The Geographical Conditions Census On The Basis Of 3S Technology

With the continuous progress of the society, the social civilization, economy and culture in China have achieved giant development after the reform and opening up. But it also resulted in the expanding population, the shortage of land resources and the destruction of the ecological environment, which have already become the current problems that need to be solved urgently. How to learn, know and apply the present situations of the geographical conditions in our country is an extremely important issue. To meet the demands of the economic development and the ecological civilization construction, the State Council formally issued the notice about carrying out the first census of the geographical conditions on February 28, 2013.This is the first time that our country decided to carry out the Census of National Geographic and it indicates that the monitoring technology for China's geographic condition has taken a step forward. At present, the geographic national census work lacks successful experience which can be taken as references and it also doesn't form a perfect and effective working plan.This paper is based on the technology of 3S, taking Wangqing County of Jilin Province as the experimental area, to research the data acquisition and processing method of census of geographical conditions. It committed to forming a complete set of data acquisition and processing schemes for geographical conditions so that it can provide technical support for the continuous carrying out of geographical conditions. The main contents of the research are as follows:(1)The integration analysis of the existing basic data. Collect and organize the basic information and geographic humanities natural data of surveying & mapping geographic information industries or departments according to the orientation and requirements of the work of national geographic census by our country and the relevant technical indicators for the national geographic census. Analyze the up-to-date characters of each data. Research the principle of its use to form a technical scheme for the use of the existing data.(2)The establishment of data acquisition program. First, integrate and refine the DLG dataand improve its value to get the most out of it according to the technology indicators and factor code classification of the census data of geogr-aphical conditions. Through the experiments with comparison and analysis, establish the corresponding relationship among the elements including surface coverage, geographical conditions and DLG data. Establish the data conversion scheme which includes correlation of data elements, data organization mode, data expression, coordinate system and so on. Second, use the DOM image data to put forward a method of combining visual and automatic ways to interpret data.(3)The verification of the field data. Use the base drawing of the field survey to do a field investigation towards the information collection results of the interior work by using GPS. And it will provide a program for the validation of the field data and the interpretation of the sample collection in mountainous regions, including the analysis towards the road accessibility, the layout of the collection point, the data generation, and the layout of the partition sample of the generated data, which greatly saves the time for the field work.Furthermore, all of these are to lay the foundation to ensure the accuracy of the data and the evaluation of quality.(4)The establishment of the census data. Through the qualitative control towards the census of the geographical conditions, the database of the census is to be established. The results of the interior data and the field data are supposed to be sorted and modified. And the topology check is to be conducted using the software. After qualification, the extraction of data is to be completed and the database of the census results of the geographical conditions is to be established.By the research of this paper, it can be concluded that 3S technology plays a very important role in the census of national geographical conditions. It shows the obvious advantage in the process of the whole data extraction. The application of 3S technology in the geographical national census improved the efficiency of collection and reduced the workload.It can provide the technical support for the continued development of the work of geographical conditions.