Interpolation Routines Assessment in ALS-Derived Digital Elevation Models for Forestry Applications

Remote Sensing

Antonio Luis Montealegre¹  Mar໚ Teresa Lamelas¹  Juan de la Riva¹  Nicolas Baghdadi² 

[1] GEOFOREST Group, Instituto de Investigación en Ciencias Ambientales de Aragón (IUCA), Department of Geography, University of Zaragoza, Zaragoza 50009, Spain; E-Mails:GEOFOREST Group, Instituto de Investigación en Ciencias Ambientales de Aragón (IUCA), Department of Geography, University of Zaragoza, Zaragoza 50009, Spain;

关键词: LiDAR;    ALS;    interpolation;    DEM validation;    CART analysis;    Mediterranean forest;   

DOI  :  10.3390/rs70708631

来源: mdpi

【 摘 要 】

Airborne Laser Scanning (ALS) is capable of estimating a variety of forest parameters using different metrics extracted from the normalized heights of the point cloud using a Digital Elevation Model (DEM). In this study, six interpolation routines were tested over a range of land cover and terrain roughness in order to generate a collection of DEMs with spatial resolution of 1 and 2 m. The accuracy of the DEMs was assessed twice, first using a test sample extracted from the ALS point cloud, second using a set of 55 ground control points collected with a high precision Global Positioning System (GPS). The effects of terrain slope, land cover, ground point density and pulse penetration on the interpolation error were examined stratifying the study area with these variables. In addition, a Classification and Regression Tree (CART) analysis allowed the development of a prediction uncertainty map to identify in which areas DEMs and Airborne Light Detection and Ranging (LiDAR) derived products may be of low quality. The Triangulated Irregular Network (TIN) to raster interpolation method produced the best result in the validation process with the training data set while the Inverse Distance Weighted (IDW) routine was the best in the validation with GPS (RMSE of 2.68 cm and RMSE of 37.10 cm, respectively).

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.