Research On Local Nonlinear Transformation Technique Of Vector Maps

In recent years, the informatization tide with the characteristic of digital and networksweeps across the whole world, all kinds of digital products emerge as the times require,geographic information system (GIS) has been an unprecedented development, and has gonedeep into the society in all walks of life. But the confidentiality and security of Vector mapdata have become a bottleneck in the development of GIS technology in China, which resultin a low penetration rate and a low resolution about the GIS technology in our country. Theso-called low penetration rate refers to the fact that high precision map data is mainly used ingovernment departments and research institutions; Low resolution refers to the fact that ourcommercial and residential digital maps are small scale maps with the scale no greater than1:25000, large scale maps are strictly controlled due to the national security. So, how toensure the confidentiality and security of the vector map data, how to make the high precision,large scale map data serve economic and social development has become an urgent problem.To solve the problem about the security issue of vector map data, hidden technology hasbeen used to classify and use maps, maps are divided into military class, government class,civil class when draw, so that the sensitive information of the map is protected. But thistechnology is high cost and inefficient. In view of the security and confidentiality issue ofvector map data, as well as today’s technology flaws, the map transformation technologycame into being.Map transformation is that under the premise of map topology unchanged irreversibletransform is used to protect the sensitive data in the map and make it no longer a confidentialmap. The vector map local nonlinear transformation technology in this paper combines themap projection technology and parallel projection technology, and makes non-lineartransformation of the area includes sensitive data, and ignores the non-sensitive areas, toensure the security of sensitive data in vector map.Experimental results show that, the local non-linear transformation technology can notonly ensure the vector map topology, map availability and transform irreversibility, but alsosafeguards the security and confidentiality of the vector map validly, so that after the processof the technology, high precision and large scale maps can be used for civil and commercialservices effectively, and it has higher practical value.