Abstract
Abstract. The newest very high resolution (VHR) commercial satellites, such as GeoEye-1 or WorldView-2, open new possibilities for cartographic applications, orthoimages generation and extraction of Digital Surface Models (DSMs). These DSMs are generated by image matching strategies from VHR satellite stereopairs imagery, reconstructing the 3D surface corresponding to the first surface view of the earth containing both microrelief (buildings, trees and so on) and bare terrain. The main aim of this work is to carry out an accuracy assessment test on the DSMs extracted from a GeoEye-1 stereopair captured in August 2011. A LiDAR derived DSM taken at the same month that the satellite imagery was used as ground truth. The influence of factors such as number of Ground Control Points (GCPs), sensor models tested and the geoid employed to transform the ellipsoid to orthometric heights were going to be evaluated. In this way, different sets of GCPs ranging from 7 to 45, two sensor models and two geoids (EGM96 and EGM08, the last adapted for Spain vertical network by the Spanish's National Geographic Institute) were tested in this work. The photogrammetric software package used was OrthoEngine from PCI Geomatica v. 10.3.2. OrthoEngine implements both sensor models tested: (i) the physical model developed by Toutin (CCRS) and, (ii) the rational function model using rational polynomial coefficients supplied by the vendor and later refined by means of the zero order linear functions (RPC0). When high accurate and well-distributed GCPs were used, the planimetric and vertical accuracies of DSMs generated from the GeoEye-1 Geo stereopair were always better than 0.5 m. Using only 7 GCPs and RPC0, a vertical accuracy around 0.43 m measured as standard deviation was attained. The geoid used by OrthoEngine (EGM96) produced similar results that the EGM08 adapted for Spain vertical network.
Highlights
Digital Elevation Models (DEMs) and Digital Surface Models (DSMs) have large relevance in some territorial applications such as modeling water flow, mass movement, topographic mapping, Geographic Information Systems, natural hazards, spatial and temporal change detection, feature extraction, visualization and many others (Deilami and Hashim, 2011)
Many new VHR satellites, capable of capturing panchromatic imagery of the land surface with Ground Sample Distance (GSD) of 1 m and even lower, such as EROS B1, Resurs DK-1, KOMPSAT-2, IRS Cartosat 2, WorldView-1, have been launched during 2006 and 2007, and they are offering to their customers very high resolution imagery of the Earth, with a very shortly revisit time
Due to the accuracy of these DSMs, they could be a direct competitors for the conventional aerial photogrammetric flights, and the choice about which product to use would be purely economic
Summary
Digital Elevation Models (DEMs) and Digital Surface Models (DSMs) have large relevance in some territorial applications such as modeling water flow, mass movement, topographic mapping, Geographic Information Systems, natural hazards, spatial and temporal change detection, feature extraction, visualization and many others (Deilami and Hashim, 2011). Many new VHR satellites, capable of capturing panchromatic imagery of the land surface with Ground Sample Distance (GSD) of 1 m and even lower, such as EROS B1, Resurs DK-1, KOMPSAT-2, IRS Cartosat 2, WorldView-1, have been launched during 2006 and 2007, and they are offering to their customers very high resolution imagery of the Earth, with a very shortly revisit time. A new commercial VHR satellite called GeoEye-1 (GeoEye, Inc., 2009) was launched in 2008 Nowadays, it is the commercial satellite with the highest geometric resolution, in panchromatic (0.41 m at nadir) and in multispectral (1.65 m at nadir) products. Image products from GeoEye-1 have to be down-sampled to 0.5 m and 2 m GSD, panchromatic (PAN) and multispectral (MS) respectively, for commercial sales, as a requirement levied by the U.S
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
