Study On The Small Area GIS Digital Surveying And Mapping Based On GPS

GIS digital surveying and mapping is the merged production of both surveying and geographical information systems. It can provides general result of digital surveying and mapping, it can also automatically creates point, polyline, polygon, as well as their topological relationship, provides dynamic updating of GIS data, ensures the accuracy and updating of GIS data. The development of GPS, especially appearing of GPS receiver for GIS, provides a new method for digital surveying and mapping. It also represents a new trend for digital surveying and mapping. In this article, we pay attention to using GPS for digital surveying and mapping, and try to explore a method of digital surveying and mapping with the simplest equipment, the least operator, high efficiency with the highest precision.First, the theory and method of GPS and digital surveying and mapping are discussed systematically in this article. DGPS is emphasizing introduced, the process of GIS digital surveying and mapping and the method of interpolate is illuminated in detail. It is indicated that DGPS can meet demands of digital surveying and mapping, and good result can be given by using DGPS.Second, the author suggests that the keys to this method are to select working mode, collect data, and process them. By discussing these three important questions, the method of digital surveying and mapping based on GPS is summarized systematically. A kind of integration of GPS technique and Portable Laser/ Ultrasonic Distance Measuring Instrument is suggested in this article, in order to overcome the shortcoming of GPS.Finally, GIS digital surveying and mapping experiment has been done in Yuzhong campus of Lanzhou University, and Differential Positioning Post Processing mode was set in the experiment. By comparing the results of GPS with map data, analyzing the reason of difference, it is demonstrated that the results of the experiment can meet demands of map with 1:10000 scale. If the better result is needed, the receiver with the better precision and the better working mode can be selected. In addition, the experiment shows that the integration can meet the demands of digital surveying and mapping in difficult condition.The research proved that, using GPS for GIS digital surveying and mapping is feasible, and we can get not only precise positions but also attributes of the feature that is saved in the computer integrated in the GPS receiver. Especially for small area in open ground, GPS are better than other methods because of its flexible method, easy using, and little cost.