地形分辨率对视线计算影响的仿真分析

Simulation Analysis of the Effect of DEM Resolution on LOS Computing

视线(Line of Sight,LOS)计算在GIS、旅游,电信等很多领域里有着广泛的应用。在描述LOS计算方法的基础上提出了表征分辨率对LOS计算影响的因子los-eff,模拟了五种典型地貌特征的地形在降低分辨率时los-eff的变化情况。实验表明降低分辨率可以使LOS计算时间近似指数下降,而在计算准确性方面,地貌特征简单的平原地形在降低分辨率后误差大于地貌特征复杂的山地地形,并且误差会随观察点高度增加而快速增加。因此可以根据不同的计算精度需要选择不同分辨率的DEM数据来进行视线计算,从而达到平衡计算时间和准确度的目的。

LOS computing has been widely used in GIS, touring, telecom and so on. The paper proposed the concept of effect factor los - eff of DEM resolution on LOS computing based on the description of the basic LOS computing algorithm, and simulated the change of los - eft using five representative physiognomy landforms after their resolutions of DEM had been reduced. The experiments showed that runtime in lower resolutions of DEM is much shorter than that in high ones and the effect factor los - eft in plain terrain with simple physiognomy is larger than that in mountainous terrain with complex physiognomy. Different DEM resolutions can be chosen on demands to get the required computing time and accuracy.