PDERL: an accurate and fast algorithm with a novel perspective on solving the old viewshed analysis problem

Chuanjun Wu,Lingxiao Guan,Gang Chen,Qing Xia,Baohong Shen

doi:10.1007/s12145-020-00545-7

Chuanjun Wu, Lingxiao Guan + Show 3 more

Open Access

https://doi.org/10.1007/s12145-020-00545-7

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Abstract

Viewshed analysis based on the regular grid digital elevation model (DEM) is one of the basic functions of geographic information systems. Traditional viewshed analysis algorithms are mainly carried out in a geospatial coordinate system, that create complexities when it is necessary to accurately express a perspective relationship. Moreover, it can only reduce the amount of calculation by using approximation methods, which result in decreased accuracy. We found that the error ratio of approximation algorithms is low but uneven and thereby highly likely to result in continuous area visibility errors. Despite the quality of DEM data having improved significantly in the last decade, traditional approximation algorithms have been unable to take full advantage of the improved data. Finding a fast and accurate algorithm has therefore become an urgent task. This study takes a new perspective to solve this problem by establishing a ‘proximity-direction-elevation’ (PDE) coordinate system and proposing a PDE spatial reference line (PDERL) algorithm within it. Many experiments prove that the accuracy of PDERL is the same as the R3 algorithm and its speed is about half that of the XDraw and reference plane algorithms, but much faster than R3. Due to the speed of PDERL, it is now possible and practical to do an accurate large-area DEM-based viewshed analysis.

Highlights

Digital elevation model (DEM) based viewshed analysis is one of the basic functions of many geographic information systems (GIS) (Qiang et al 2019; Wang et al 1996) and has broad applications. Teng et al (1993) used viewshed analysis for topographic path planning, Winter-Livneh et al (2012) and Bongers et al (2012) used it for archaeological research, and Qiang et al (2019) used it for visibility analysis of oceanic blue space
With the rapid improvement in accuracy of modern DEM products, the calculation error present in the traditional fast approximation algorithms has become the main source of error in viewshed analysis (Zhu et al 2019)
Efficiency can only be improved by using approximation methods, which result in a decline in accuracy

Summary

Introduction

Digital elevation model (DEM) based viewshed analysis is one of the basic functions of many geographic information systems (GIS) (Qiang et al 2019; Wang et al 1996) and has broad applications. Teng et al (1993) used viewshed analysis for topographic path planning, Winter-Livneh et al (2012) and Bongers et al (2012) used it for archaeological research, and Qiang et al (2019) used it for visibility analysis of oceanic blue space. Digital elevation model (DEM) based viewshed analysis is one of the basic functions of many geographic information systems (GIS) (Qiang et al 2019; Wang et al 1996) and has broad applications. Teng et al (1993) used viewshed analysis for topographic path planning, Winter-Livneh et al (2012) and Bongers et al (2012) used it for archaeological research, and Qiang et al (2019) used it for visibility analysis of oceanic blue space. The study of viewshed analysis is based on the concept of line of sight (LOS), which refers to the line connecting an observer and a target (Franklin et al 1994). It is necessary to know the standing positions of an observer, a target, and the intervening

Methodology

Discussion and conclusion

Findings

Compliance with ethical standards