ACCURACY INVESTIGATION OF DEM BASED ON GÖKTÜRK-2 STEREO IMAGES

Öz

In December 18, 2012, Gokturk-2 satellite has been launched to the space from the Jiuguan station in China. The satellite has the pushbroom camera, which could enable to take panchromatic imaging with 2.5 m resolution and multispectral imaging with 5 m resolution at the height of 685 km. Satisfying the requests of Turkish Armed Forces, Turkish government agencies and institutes for satellite images has been aimed by the data provided by Gokturk-2 satellite. High Resolution Satellite Images (HRSI) have been extensively used in such fields as mapping, intelligence service, exploration, monitoring of environment, agriculture and change tracking; mapping is one of the most widespread application areas of HRSI.

In order to use satellite images like a map, geometric deformations should be removed; in other words, the deformations are required to be orthorectified. The model, Ground Control Points (GCP) and Digital Elevation Models are needed for an accurate orthorectification application.

In this study, block adjustment was made by using 20*60 km sized stereo image of Gokturk-2 satellite, GCPs and Check Points (CP) in different numbers. Average errors in X, Y, Z dimensions were analyzed at the end of the adjustment. Furthermore, the accuracy of Digital Elevation Model was controlled by the heights of primary bench marks.