CARTOSAT-1: ORIENTATION, DEM AND ORTHORECTIFICATION QUALITY 
ASSESMENT 
R. Dabrowski a , W. Fedorowicz-Jackowski 3 , M. Kedzierski b , R Walczykowski 6 , J. Zych 3 
3 Geosystems Polska Sp. z o.o., ul. Smolna 38/5, 00-375 Warszawa, Poland - 
(rafal.dabrowski, witold.fedorowicz)@geosystems.com.pl 
b Military University of Technology, ul. Kaliskiego 2, 00-908 Warszawa, Poland - 
(mkedzierski, pwalczykowski)@wat.edu.pl 
Commission I, SS-11 
KEY WORDS: Photogrammetry, Digital, Orthorectification, DEM/DTM, Satellite, Accuracy, 1RS 
ABSTRACT: 
CARTOSAT-1 is an Indian satellite - the 11 th one in the IRS (Indian Remote Sensing) series designed to provide quality Earth 
imagery for telemetry and digital mapping. The satellite carries two panchromatic sensors capturing images forward (26 degrees) and 
backwards (5 degrees). Images are recorded almost simultaneously in both directions along the satellite’s orbit plane or with an 
inclination, if needed. The sensors cover the swath about 30 km wide with the resolution of 3 m (+26 degrees) and 2,5 m (-5 degrees). 
This article summarizes the findings of the research programme aiming to verify the quality of the imagery acquired by Cartosat-1. 
The verification was conducted using a test scene located in Poland. The research team included engineers from Geosystems Polska 
and scientists from Military University of Technology, Warsaw. The imagery was processed with Leica Photogrammetry Suite 
software. 
1. INTRODUCTION 
To assess the quality of imagery from Cartosat-1 and its 
viability for Earth’s Digital Elevation Models ISRO and ISPRS 
started a research programme named C-SAP (Cartosat Scientific 
Assessment Programme) inviting companies and institutions 
with appropriate human and technical resources. Sixteen 
Principal Investigators were chosen to provide reference data. 
The authors were part of the Principal Investigator responsible 
for the Test Site 9 (TS-9). 
2. INPUT DATA 
2.1 Image Data 
2.2 Reference data 
DEM: As required by C-SAP the Principal Investigator (PI) 
responsible for TS-9 provided two reference terrain models 
from two independent sources: a Digital Elevation Model 
(DEM) with the resolution of 25 m generated from topographic 
maps and a DTED-2. 
GCPs: To provide flexibility in data analysis, 36 Ground 
Control Points (GCPs) were established. The GCPs were 
distributed evenly over the stereopair. After a field survey the 
number of GCPs was reduced to 31 due to difficulty in 
identifying the correct location of 5 of them. As a general rule, 
GCPs were placed where roads or paths crossed, though in 
some areas only fence comers provided enough reliability. 
The coordinator of the CSAP-ISRO programme provided a 
stereoscopic pair of images acquired on February 25‘ , 2006. 
The pair covers an area located slightly over 100 km South- 
West of Warsaw, the capital of Poland. The scenes were rated 
good quality though due to the winter season most of the area 
was covered with snow. 
Figure 2. GCP distribution in the scene. 
Figure 1. The after (left) and forward image. 
The GCP field survey was conducted with a GPS receiver using