Title
Bias estimation and correction for triangle-based surface area calculations.
Abstract
The calculation of surface area is meaningful for a variety of space-filling phenomena, e.g., the packing of plants or animals within an area of land. With Digital Elevation Model DEM data we can calculate the surface area by using a continuous surface model, such as by the Triangulated Irregular Network TIN. However, just as the triangle-based surface area discussed in this paper, the surface area is generally biased because it is a nonlinear mapping about the DEM data which contain measurement errors. To reduce the bias in the surface area, we propose a second-order bias correction by applying nonlinear error propagation to the triangle-based surface area. This process reveals that the random errors in the DEM data result in a bias in the triangle-based surface area while the systematic errors in the DEM data can be reduced by using the height differences. The bias is theoretically given by a probability integral which can be approximated by numerical approaches including the numerical integral and the Monte Carlo method; but these approaches need a theoretical distribution assumption about the DEM measurement errors, and have a very high computational cost. In most cases, we only have variance information on the measurement errors; thus, a bias estimation based on nonlinear error propagation is proposed. Based on the second-order bias estimation proposed, the variance of the surface area can be improved immediately by removing the bias from the original variance estimation. The main results are verified by the Monte Carlo method and by the numerical integral. They show that an unbiased surface area can be obtained by removing the proposed bias estimation from the triangle-based surface area originally calculated from the DEM data.
Year
DOI
Venue
2016
10.1080/13658816.2016.1162795
International Journal of Geographical Information Science
Keywords
Field
DocType
Terrain, DEM, surface area, area bias, bias estimation
Data mining,Monte Carlo method,Nonlinear system,Propagation of uncertainty,Terrain,Algorithm,Digital elevation model,Bias correction,Statistics,Triangulated irregular network,Mathematics,Observational error
Journal
Volume
Issue
ISSN
30
11
1365-8816
Citations 
PageRank 
References 
1
0.36
12
Authors
8
Name
Order
Citations
PageRank
Shuqiang Xue111.37
Yamin Dang212.72
Jiping Liu3116.00
Jinzhong Mi411.71
Chun Dong510.36
Yingyan Cheng610.36
Xiaoqing Wang7388.28
Jun Wan810.36