Study And Practice To The Automated Generalization Of Road Networks

Traffic network is the total of all traffic route ways including roads and conduits in land, lines in air and water, additional objects and symbols related with traffics. Road networks are the roads in land; it is part of traffic networks. Roads are in all of the maps and they are various and complicated with many grades. At the same time, the road layer is important and frequent used among all the layers in map. It is important to military, too. For all these reasons, road networks generalization is very complicated and important among all layers. With the increase of map information and the development of computer and pertinent technology, there're many problems in road networks generalization. There are detailed researches and practices in this thesis. The main works and creations are as follow:1. Present methods of road networks generalization are introduced. Two different types of road networks are departed which are grid-like and irregular pattern, according to the characteristics of road networks. And then roads with different methods are selected in different patterns. At last, a series experiments have been done comparing the other methods with the used method, and the used method has been proved applicability.2. Several simplifying methods in common use are introduced. Six targets are proposed for analyzing the advantaged and shortage of simplifying methods. These targets have been used to estimate two common methods (Douglas-Peucker and Beam of Light) and some useful advises and corrections have been got. The six targets can also be used to other methods.3. A new method is excogitated to avoid the shortage of former method through analysis. This method is explained in detail and experimented with road data.4. Road-displacement is analyzed and improved based on present methods, and being more applied than before. The conflicts of inter-road and among roads are analyzed. Displacement or both-side is used for different condition among roads supported with rule storage. Two different ways are used to deal with the size of displacement of conflict in different condition.5. Automated match of digital map edge is realized by program according to the requirement of automated generalization. The program can mend half position between jointed maps or one map according to the better-quality map with different parameters.6. At last, the system of road networks generalization has been developed which includes all generalization models and methods in this thesis.