The Technique And Application Research On SAR Images For 1:50,000 Topographic Mapping In Hengduan Mountains

In order to fill up the 1:50,000 topographic maps blanks of Hengduan mountains in China's western quickly and serve to the national economic construction better,1:50,000 topographic mapping in Hengduan mountains is regarded to the key item of western region mapping project. State Bureau of Surveying and Mapping decides to complete the mapping task between the year of 2009 and 2010, in this way, we can build up the national 1:50,000 basic geographic information database and the thematic elements databases at real meaning. It can provide timely,reliable and applied surveying guarantee and geographic information service.Taking into account the difficult environment of no maps region in Hengduan mountains, the mapping in this region cross over the traditional mapping mode, a great number of new aerial and satellite remote sensing techniques are adopted, such as:IMU/DGPS supported aerial photography,high resolution satellite image,Synthetic Aperture Radar(SAR) image mapping and so on. Moreover, the mapping method based on few/no ground control points are used to realize the 1:50,000 topographic mapping. The main research results are as follows:1. The exterior orientation elements of bands are calculated by the information file of High-resolution satellite images SPOT-5/IRS-P5, then, the Rational Polynomial Coefficients(RPC) of Rational Function Model(RFM) are computed. Few ground control points are imported to apply block adjustment. After that, control points are chosen by the way of image to image using SAR images and SPOT-5/IRS-P5 satellite images. On the other hand, field control points are obtained by corner reflector. All the control points are used to process SAR images combined adjustment, the photographic points can be computed by this way, and the control surveying of SAR images can be carried out.2. Through the analysis on stereo model restoration of SAR image,objects gathering and landform elements, we research the key technology of SAR image mapping and the SAR image points computation by SPOT-5/IRS-P5 bundle adjustment. Then, the problem of no contol and mapping difficulty in Hengduan mountains unmanned areas.3. Through the analysis on production basic requirements,technical indices,technical flow of Digital Orthophoto Map(DOM),Digital Line Graphic(DLG),Digital Elevation Model(DEM), the key technology in the practical production of DOM,DLG and DEM. The production process quality control methods are provided by the analysis on quality control elements and characteristics in practical production process.4. C1 regional maps in Hengduan mountains are selected as an research example in this paper, we present the technical flow of 1:50 000 topographic map production. Moreover, using field check points, we evaluate the accuracy of DOM,DLG and DEM data production based on SAR images. Results verify that the 1:50000 topographic map production methods in Hengduan mountains area provided in this paper is feasible.