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IC 
IACCURACY ASSESMENT OF HIGH RESOLUTION SATELLITE IMAGES 
L. Iscan **, O. Aksu?, M. Onder ^, V.O. Atak *, O. Lenk ©, M.A. Gurdal “ 
* General Command of Mapping, Photogrammetry Department, 06100 Mamak Ankara, Turkey — (liscan, oaksu, 
oatak)@hgk.mil.tr 
? General Command of Mapping, Chief of Technical Departments, 06100 Mamak Ankara, Turkey — 
monder@hgk.mil.tr 
* General Command of Mapping, Geodesy Department, 06100 Mamak Ankara, Turkey — (olenk, agurdal )@hgk.mil.tr 
Commission IV, WG IV /7 
KEY WORDS: Photogrammetry, Remote Sensing, Measurement, DEM/DTM, GPS, Satellite 
ABSTRACT: 
High resolution satellite images (Ikonos, Quickbird, etc...) supply a lot of opportunities in mapping, GIS and many other 
applications by means of the improvements in Remote Sensing technologies. A test study has implemented in Turkey by General 
Command of Mapping (GCM). Golbasi case study area near Ankara, which is 10kmx10km and already used for kinematic GPS 
supported aerial triangulation test project in 1996, has been selected for accuracy assessment of high resolution satellite images. 12 
ground control points were revised and signalized before the recording of images. 
Stereo-pair IKONOS (dated August 4th, 2002) and mono QUICKBIRD (dated 26th May, 2002) images covering test area have been 
provided by Inta Uzay Sis.A.S (Turkey) and Eurimage (Italy) free of charge. Various ortophotos have been produced from aerial 
photograph, IKONOS and QUICKBIRD images with; 
- photogrammetric DEM 
- cartographic DEM 
- with/without ground control points 
- polynomial constants (rpc file) 
Well-distributed 27 checkpoints such as junction of roads, field corners have been defined and planimetric coordinates were 
measured on all orthoimages. GPS measurements of checkpoints and calculations of orthometric heights have also been 
implemented. Obtained results and comments are given in that paper. 
1. INTRODUCTION 
  
  
  
  
New opportunities in photogrammetry and remote sensing 
applications have been initiated by launching of IKONOS in A A 
1999 and QUICKBIRD in 2001. These high resolution satellite 130 A 800 
image are being used widely day by day in various fields for 313 
various purposes both in Turkey and abroad. A 
S ; ; 307 A 
Considering the accuracy assessment for geographical 
information provided by those images, a test study has 303 
implemented in Turkey by General Command of Mapping A 
(GCM) and obtained results have been given in that paper. 312 A 
A 
2. PROJECT AREA AND INPUT DATA 302 A 
Golbasi case study area near Ankara, which is 10kmx10km and A 817 
already used for kinematic GPS supported aerial triangulation A 131 A 
test project in 1996, has been selected for accuracy assessment 303 310 
of high resolution satellite images. 12 ground control points (in : 
figure 1) were revised and signalized before the recording of Figure 1. Distribution of GCP’s in project area 
images. 
  
* Corresponding author. 
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