remote sensing

Figure: Ortho-Photo Mosaik from Kelurahan Tumbang Tahai and BOSF Station Nyaru Menteng with tracks superimosed on Landsat-image from 2003 (Rungan river)
by Viktor Boehm and Alvand Miraliakbari
 

The area along prallel to river Rungan was scanned with a LiDAR and a Hasselblad Camera 5 times with an overlap in an average altitude of 500m on the 7. August 2007. The weather was good. Beside LiDAR data RGB-Photos were taken with a Hasselblad camera of 22MB image size (5440 x 4080). These RGB-Photos had in flight direction and to the side an overlap. For the  area we collected more than 50 RGB-Photos. The orientation parameters (x, y, z, flight altitude, tilt angles, time, camera boresight) were stored during the helicopter flight. They were first used to ortho-rectify the RGB-Photos.

An automatic aerial triangulation process was used to generate an Ortho-Photo Mosaik. Next step was the Ground Control Point (GCP) measurements which were taken in the LiDAR data. This was carried out with the multi photo measurement tool. Most of those GCPs were found along road intersections since they are easy to find.
The final Ortho-Photo-Mosaik from this area was 7.5km respectively 3.5km long and had a pixel resolution of 0.2m x 0.2m. The Ortho-map above has a 5x reduced resolution!!!  
The Ortho-image was processed on 21.9.2010