| People need it in different resolution ratios more and more, observe, understand and describe the geographical phenomenon on different space yardstick, namely need to analyse , deal with and express to the space data of many kinds of scales more and more. This has caused appearance of mult- scales characteristic GIS demand.The research of automatic cartographic generalization is a very difficult subject.Now recognizing the road network by hand tracing is used generally in the creation of the vector map. It's time consuming and inefficient by this means. Moreover, it's difficult to update timely. Can utilize the geographical data of foundation in existing GIS database based on single scale , produce mult-scale data synthetically through automatic cartographic generalization. Obviously , gather , store , management and newer input in reduction mult- scales data that this kind of method not only can be great, and can expand the service surface of GIS basic database , improve its potential using value. So the research of automatic cartographic generalization and GIS linear linear key element is one of the key technology of the digital map.The purpose of the thesis is to utilize UML to improve GIS figure modeling and apply to figure modeling course with GIS linear data simplifying and automatic cartographic generalization.Basing on the recent production of automatic cartographic generalization and GIS linear data simplifying, I design the arithmetic arming to progress it. The ameliorated part include: B-spline inserting and precision controling based on classing feature point of the irregular curve characteristic; The simplifying of GIS linear data based on limit of resolution ratio of human eye; Based on linear data of GIS the naturally wavelets base is constructed.; Hand in the experiment of simplifying in such data as road network , network of waterways , contour ,etc. of Orthogonal cycle wavelets. |
