An Accuracy Assessment of Cartosat-1 Stereo Image Data-Derived Digital Elevation Models: 
A Case Study of the Drum Mountains, Utah 
Gayla A. Evans a , Bhaskar Ramachandran b , Zheng Zhang b , G. Bryan Bailey 3 , and Philip Cheng' 
a U.S. Geological Survey, Earth Resources Observation and Science Center, Sioux Falls, SD, 
USA-(gevans, gbbailey)@usgs.gov 
b ADNET Systems Inc.* Contractor to the USGS EROS Center, Sioux Falls, SD, USA-(bhaskar, zhang)@usgs.gov 
c PCI Geomatics, Richmond Hill, Ontario, Canada-(cheng)@pcigeomatics.com 
KEYWORDS: Cartosat-1, DEM, NED, ASTER, DOQQ, Vertical, Horizontal, Accuracy 
ABSTRACT: 
This study evaluates the accuracy of digital elevation models (DEMs) produced from Cartosat-1 data. The Cartosat-1 satellite, 
launched by the Indian Space Research Organization (ISRO) in May 2005, carries two panchromatic cameras capable of acquiring 
stereoscopic data along the orbital track. These data provide the potential to produce high-quality DEMs for virtually any location on 
the Earth’s surface. Cartosat-1 DEMs produced for the Drum Mountains study site in west-central Utah are compared to a number of 
reference data sets. The vertical accuracy is compared against NED, ASTER, and SRTM DEMs. The horizontal accuracy is 
compared with the Digital Orthophoto Quad data. Cartosat-1 DEMs compare quite well with the most accurate reference DEMs. 
1. Introduction 
In May 2005, the Indian Space Research Organization (ISRO) 
launched its Cartosat-1 satellite, which carries two cameras 
that acquire panchromatic stereoscopic images in the visible 
region of the electromagnetic spectrum. Cartosat-1 
stereoscopic data are particularly useful for producing digital 
elevation models (DEMs) of the Earth’s land surface. This 
study evaluates the vertical and horizontal accuracies of the 
Cartosat-1 DEMs produced with commercially available 
software systems. A similar study (Bailey et al., 2006) was 
carried out in 2006 with the same Cartosat-1 data, and those 
results are incorporated as part of this paper. 
This area is semiarid and sparsely vegetated, and contains 
more than 600 meters of relief with slopes that range from 
steep to very gentle. 
2. 
Study Area 
The study area for this investigation is the central part of the 
Drum Mountains, which are located in west-central Utah 
(Figure 1). These mountains comprise a lithologically diverse 
landscape in a complex structural setting within the Basin 
and Range physiographic province of the western United 
States. The Basin and Range province topography is 
characterized by elongated north-south trending valleys, 
which are bounded by adjacent fault-block mountain ranges. 
Figure 1: Geographical location of the Drum Mts, Utah 
(Source: Google Earth) 
Work performed under U.S. Geological Survey Contract 08HQCN0005 
1161