3D Locating System of Observation Tower with Multiple Constraints

摘要

The viewshed of a topographic dataset is the region around a given observation point that is visible from that location. The viewshed analysis which is an important function of GIS often is used to locate observation towers with DEM data. However, location problem of observation towers is not only a simple GIS analysis to compute viewshed of each observation tower, but rather a complicated locating model to optimize locating schemes for building tower. This paper abstracts the location problem with the actual constraints of building tower, and tries to establish a locating model with linear programming ideas. The core of the locating model is to choose more cost-effective viewshed in all of towers to be built, that is, the area of viewshed/building cost would be as high as possible.rnBased on the locating model, an automated software tools are developed to solve the practical problem efficiently. First, candidate points are extracted from peaks using neighbor analysis method based on DEM. Then, according to the type of tower and its parameters such as visual distance and cost, the viewsheds of multi-type tower are calculated on every candidate point, and all viewshed area/cost of all type towers are computed and ordered by descending. Finally, the linear programming problem is solved by a software system based on locating model and the result scheme of building tower is automatically calculate from candidate points. The location result can guarantee that the surface of given DEM is fully covered by viewsheds of all towers and cost of building towers is the minimum.rnThe software system can automatically generate a guided interactive location scheme, which can be analyzed with multiple angles of towers siting distribution, type, observations area and 3D scene. It indicates that location result has good reference value for making decision.