Research on Topographic Map Updating with Incremental Mode Based on Remote Sensing Images

Transcription

1 Research on Topographic Map Updating with Incremental Mode Based on Remote Sensing Images XIONG Junnan, JIA Hongliang, YANG Yanmei School of Civil Engineering and Architecture, Southwest Petroleum University, Chengdu, China, Abstract: With the completion of the database of 1:5 million, and the basic geographic information database of 1:1 million were begin construction, how to quickly update the map data, and ensure the current situation of map data has become an important challenge which GIS Field facing. This paper analyzes the current map update methods, focuses on the key technologies and technical process on the use of remote sensing images updating 1:5 million topographic map, after the experiments on updating topographic in Wenchuan earthquake affected area use remote sensing image, The results show that the use of remote sensing images update topographic maps is a fast, effective method. Keywords: Remote sensing image, potential, Map update, Incremental mode 1 Introduction 1:5 million topographic maps are basic maps in various departments of the national economy and national defense construction, has played a significant role in the local, national, global economic growth, environmental quality and stability, and social development. Currently, the construction speed of national economy accelerated, the surface feature changed more than 5% each year in cities, about 4% in rural towns and residents to dense, at the same time, disasters occur frequently in recent years, such as the 5.12 Whenchuan earthquake, August 7 Zhouqu large debris flow, resulting in a lot of damage to residential and landscape changes, so the original topographic map of the potential and accuracy are reduced. Therefore, accelerating the speed of updating topographic maps, in the national economic construction and social development in terms of basic mapping support is important. At present, the reality of data update is not so optimistic, the United Nations statistics show that 90 of the last century, the global topographic map of the update rate is far behind its production rate. China built a 1:25 million, 1:5 million scale basic geographic information database. 1:5 million scale topographic map data base have about 19,000 pieces of data, and its update work are very huge and difficult. Therefore, topographic map updating method of theory and technology is a premise to achieve quick update topographic maps. 2 Method of Topographic Map Updating The purpose of Topographic map update is to make the contents of map line with realities on the ground, according to the current mapping pattern, specifications reprinted to meet the needs of economic construction, national defense, science and technology development. Topographic map updating methods include orthophoto updated, aerial mapping method a sub-painted, three-dimensional mapping update, digital mapping update, remote sensing image updates etc. A sub-painted aerial mapping method is widely used in 90s last century, it use the latest photogrammetry data and Previous research, take analytical method block adjustment encryption control points on the instrument in three-dimensional mapping Revision and geomorphology, revision and surface features, the sub-version of carving, painting and finishing outside the business supplement, updated version of original map in one time. It s an effective method to update mountainous and hilly areas topographic maps. For flat areas, use photo to update are much better. Orthophoto map update is the corrected 72

2 orthophotos and topographic maps for the original registration, use of superposition of two plans to identify and detect changes to update the original topographic Remote sensing for updating topographic maps, is registration high-resolution images with the original DLG, use the superposition of two graphs, identify changes in surface features, and digitize the changed surface features to update existing surface features, to achieve topographic map updates. Current research concentrates on how to use high-resolution remote sensing image automatic registration with target data of digital vector maps; how to automatically extract spatial variations elements from the remote sensing image, and intelligent update vector digital maps; image data and vector data Pattern matching and information conversion. With resolution of remote sensing image become more and more high, making observations surface detail changes in a smaller spatial scale become possible. Therefore, by high resolution remote sensing images to achieve the topographic map updating has become a more efficient means. The choice of image data directly affect the accuracy of topographic map updating and quality, so, we need to select reasonable Spatial resolution and band, clear remote sensing images as a data source. The image data which Meet the precision require of variety scale topographic map update are list in Table 1.The main technical process of map update are shown in Figure 1. Tab.1 Updated topographic maps and remote sensing image data source correspondence Scale topographic map Remote sensing image data Spatial resolution /m 1: LandsatMss or Landsat TM 80/30 1: Landsat TM 30 1:50000 Landsat ETM+ 15 SPOT5 Multi-spectral bands 10 1:10000 QuikBird Panchromatic bands 0.61 IKNOS-2 Panchromatic bands 1 1:5000,1:2000 QuikBird Panchromatic bands :1000,1:500 Aerial Image Data 3 The Key Technologies of Use Remote Sensing Updating Topographic Maps 3.1 The registration of Remote sensing images and topographic maps Update topographic maps using remote sensing image data in general practice: compared 1 images and maps, manual select control points; 2 Relative correction for the images and maps; 3 compare with superimposed images and the map, add "new surface features", delete or modify Old (have been removed or changed) features. Because the terrain maps are the result of processing and symbolic, and images are surface features of the "photo", Digital topographic map Remote sensing image Image Enhancement Geometric correction Image Fusion Digital topographic maps and remote sensing image overlay, matching Discover the update scope Using satellite images updated Topographic maps Edit Finishing Figure 1 Technical process of use Remote sensing image update topographic map 73

3 both of which have many difference, such as the width of the railway on the vector map (usually the centerline) and the width of the image is different Some surface features on the vector maps, landscape changes may have occurred, the central projection of the remote sensing image and surface features compared with map are exist "shift"(ortho-image of its above ground buildings and other remains a central projection features), therefore, images and maps to ensure accuracy of the relative alignment, with the obvious time and the corresponding surface features should be selected points, usually a scene should be at least 50 control points selected and should be evenly distributed throughout the image. For the region have undulating terrain, needs to be ortho-rectified using DEM. First of all to carry out format conversion, change the DEM data adapt image processing platform; if DEM is the other coordinate system, there must be a projection transformation; DEM generally less than the range of areas of the image, and therefore the DEM mosaic. 3.2 Automatic Discovery Feature Change Currently in the process of updating topographic maps, the found of feature changes mainly use the way of visual judging, after registration the image map with topographic map, by comparing the change in interpretation of various features on the location, according to the change collect feature points like screen digital. Change detection and update automatic are the best way for people to pursue, it can realize real-time, on-orbit (that is intelligent sensors), but it also the most difficult method. Professor Li Deren think that, detection method can be divided into two categories of seven methods according to the two factors of image registration and change detection. The first detection method is to do the image rectification at first, and the second method is change detection synchronized with the image registration. Which old and new images based on change detection, based on new images and old DLG change detection, based on the number of old and new images and old maps of the change detection, multi-source image based on the new and old images / old maps for change detection is the first after image registration method for change detection. Based on the existing DEM, DOM, and new images for change detection is not correct, based on the old DLG, DRG, and the new image change detection is not correct, based on existing products and new three-dimensional 4D overlapping three-dimensional image change detection method Change detection is synchronized with the image registration method. 3.3 Collect Change information After registration and find updating region, we can use ARCVIEW GIS software to complete Topographic map updates. (1) The generation of digital contours can make in ARCVIEW GIS-3D Analyst extension module. Application system conversion (Convert to Grid) will be converted DOM into GRID, and then use "Create Contours" from the Grid to complete the conversion to digital contour lines, isopleth are Prepared for update the contour lines. (2) DRG hierarchical vector and construct database.to update the topographic map, you must first stratified vector DRG, all the pixels of DRG based on their geometric features extracted as point-like hierarchical elements (such as bridges, etc.), linear elements (such as roads, single river, canal Etc.), area feature (such as residential, independent mining, forest, etc.) three categories. Because ARCVIEW GIS has a strong function of vectorization, in order to avoid errors when data import, the vector process carried out in the ARCVIEW GIS. In ARCVIEW GIS layer for each vector corresponds to an attribute database should be building a database in the process of vector At the same time. With complete the work, will be done by the old topographic maps to digital maps of the transition. (3) Layer by layer Updated based on image interpretation. Layer by layer update refers to the vector for each layer of spatial data and attribute data synchronized, that is not only complete update each pixel in the geometric properties, but also complete property database updates. Each element of the vector layers and satellite images were superimposed display, and with reference to DRG, visible details of the two images of the landscape, and an objective reflection of 74

4 the orthophoto real landscape near the ground, easy to read and use, increase amount of information, at the same time raster images and vector graphics complement each other, carefully looking for change and change, and other information that add and disappear through the interpretation of satellite images to complete the step by step update. In addition, county and township industry sector according to the requirements and other administrative boundaries of land use data and information on the Home Office to adjust, geographic names and other attribute data by government departments, local updates the information provided; and contour line layer is from the DEM the number of contour lines generated to update the composite. Updating the end point layer, but also completed a topographic map 1:5 million basic geographic information database and old topographic maps generated by the electronic map updates. 3.4 New data fusion with not changed data This is a multi-source, multi-scale data sets of the fusion process, the new collection is about to change information in the database does not change the original information fusion, to form the current potential of the new integrated database. Original data may be added, disappear, change and other changes in the type, the corresponding processing, including: (1) Inserted. The surface features will be added to the database information. (2) Deleted. Surface features would have been lost to delete information from database. (3) Match and replace. According to similarity criteria, the spatial form and location change of surface features to match the original data to determine the replacement object, then the new data replaces the contents of the changed In this process, key issues that need attention include: (1) Evolution of data models. Different periods of data acquisition and collection are often based on different data models, resulting in the expression of the same terrain with multiple objectives, and its topological, semantic and metadata are different and need to be matched. (2) The standard of Scale and data quality. The scale of data acquisition and collection of data quality standards vary and will result in data gaps; the same data model, multiple access will also coordinate the different position and different features on the interpretation of some differences, need to be eliminated. (3) Need to provide sufficient metadata to track the update process (4) Matching method include artificial matching, interactive matching, automatic matching, especially in the automatic assessment of matching points, automatic matching algorithms and tools is the current hotspot, it is worth noting that not all of the update process can be automated. 4 Experiment Study area is located in northwest Sichuan, hit area of Wenchuan earthquake, which is the jurisdiction of Jiangyou City, terrain elevation greater maximum elevation of 2402m, the minimum elevation of 590m. Overall the study area in the low mountain topography in the main, east and west was quite high, the central part and north-south low-lying, and there are two more open mountain valleys, rivers, roads and towns along the north-south trending. The area lies in earthquake intensity is 7 degrees area, the earthquake triggered a large number of landslides, collapse hazard, some houses were damaged and residents to landscape changed significantly. Topographic map of the last century the early 90's aerial mapping, part of the study area, the terrain are shown in Figure 2, the current situation and geometric accuracy are difficult to meet the needs of reconstruction, it is imperative to carry out the update topographic maps. 75

5 Figure 2 The original topographic map Figure 3 The remote sensing image use to Update Used ADS40 aerial images which after the earthquake to update the image, shown in Figure 3, by determining the update strategy, image and topographic map registration, changes in access to information, change information collection, the new data does not change with the data fusion step, layer by layer to be updated To complete the updating of topographic maps. 5 Conclusion (1) Using remote sensing images to update Topographic maps, after select remote sensing images to meet the accuracy requirements, registration accurate of topographic maps and remote sensing is the key problem of ensure update result accuracy. (2) Experiments show that the use images to updates topographic map is a practical and fast methods should be promoted to accelerate the pace of reconstruction, can do important role in rehabilitation of infrastructure affected areas. Acknowledgement: This study was supported by the technology fund of Southwest Petroleum University (2010XJZ180) Technological innovation seedling projects of Sichuan Province ( ) References [1]. JIANG Jie, CHENG Jun. Some Consideration for Update of Fundamental Geo-information Database[J], Bulletin of Surveying and Mapping2000(5):1-3 [2]. LIU Xuejun. The Update cycle research on 1: topographic map [J],China Surveying and Mapping,1994(2),9-14 [3]. PAN Shixiang, YANG Dingguo etc. The Revision of 1:50000 Maps in China [J], Journal of Institute of Surveying and Mapping, 1988(2):37-41 [4]. CHENG Jun, ZHAO Renliang.Key Issues of Continuous Updating of Geo-spatial Databases [J], GEOMATICS WORLD,2004(5):1-5 [5]. JIAN Chanliang, RUAN Hongli. Using high-resolution remote sensing satellite images updated1:1 million Scale digital topographic map [J],Science of Surveying and Mapping, 2006 (Supplement) [6]. ZHANG Baogang, YUAN Yanyan. Automatic Discovery of Feature Change Based on the Database of Urban Large Scale Topographic Maps [J], Geomatics and Information Science of Wuhan University,2005,30(7): [7]. ZHANG Baogang, SHI Qiang. Incremental update topographic map database [J], BEIJING SURVEYING,2007(1):1-4 [8]. LI Deren. Change Detection from Remote Sensing Images [J], Geomatics and Information Science of Wuhan University, 2003, 28(Supplement):