Evaluation of prediction methods for elevation determination using SRTM digital elevation model in Akure, Ondo State

Abstract

The Shuttle Radar Topography Mission (SRTM) was flown aboard the space in February 2000. The National Aeronautics and Space Administration (NASA) and the National Geospatial-Intelligence Agency (NGA) participated in an international project to acquire radar data which were used to create the first near-global set of land elevations. This paper deals with the accuracy assessment of elevation data obtained using SRTM from each of the eleven (11) selected interpolation algorithms, including Inverse Distance Weighting, Natural Neighbour, Spline Regular, Spline Tension, Universal Kriging, Empirical Bayesian Kriging, Topo to Raster, global (trend surface), local polynomial, kernel interpolation with barriers and radial basis functions in DEM surface creation. The data was compared with reference to ground control points of differential Global Positioning System (DGPS) field observations in the study area. The error statistics was generated between DGPS measurements and Extracted elevation data from each selected interpolation method and it was observed that elevation data extracted from Inverse distance weighting, Natural Neighbour, Spline R, Spline T, Topo to Raster, Universal Kriging, Empirical Bayesian Kriging, Global polynomial interpolation (GPI), local polynomial interpolation (LPI), Radial basis function and Kernel interpolation are ±8.446, ±8.648, ±9.532, ±10.707, ±10.020, ±9.795, ±8.452, ±14.565, ±9.266, ±10.802 and ±11.303 respectively when compared with elevation values from GPS with Inverse Distance weighting Interpolation method showing the best overall accuracy of ±8.446m.