Sadegh Karimi - Department of Geomatics Engineering, K. N. Toosi University of Technology, Tehran, Iran
Ehsan Khorrambakht - Department of Aerospace Engineering, K. N. Toosi University of Technology, Tehran, Iran

Topography maps are crucial for civil engineering projects, such as road construction, water channel construction, urbanconstruction, and mining. Here we present a method which enables us to extract topographical map via modeling GoogleEarth and some field works. In this method, first, we model Google Earth as an object with closed-range photogrammetricmethod in the Agisoft Photoscan. Through some field works, we measured twenty-two points including twelve groundcontrol points (GCP) and ten independent check points (ICP). Due to these GCPs, we were able to transform our model toreal world with global polynomial and multi-quadratic equations and ICPs were used for precision analysis. This methodis easy and cheap to obtain spatial data and the accuracy is sufficient for research requirements.

Photogrammetric Method; Data Extraction; Google Earth; Modelling; Agisoft Photoscan; Data Processing; Multi -quadraticTransformation