Geometric aspects of digital frame cameras for aerial photogrammetry (2009)

Team:  Karsten Jacobsen
Year:  2009
Duration:  since February 1999
Is Finished:  yes

Cooperation with : Z/I Imaging, Oberkochen and Tang Ingenieurconsult, München

Background and goal

Different companies have recently announced digital aerial cameras on the basis of CCD chip technology. Two competing developments are those using linear and matrix sensors. Due to the large field of view and consequently a large image plane to be covered required in aerial photogrammetry different matrix sensors have to be merged together to realise a CCD camera based on 2D sensor technology.
In this project we investigate the geometry of the DMC (Digital Modular Camera) developed by Z/I Imaging. It is the goal to prove that the DMC has at least similar geometric characteristics when compared to a traditional aerial film based camera.

Tasks and methods

The DMC contains different matrix CCD sensors operating in parallel. Each sensor has its own camera head and lens and images a so called sub-image. This modular approach ensures a simple scalability of the whole system. Up to four panchromatic sub-images of 4kx7k pixels each and four multi-spectral sub-images of 3kx2k pixels each in blue, green, red, and infra-red can be captured simultaneously. The stability over time of the interior orientation of the individual camera head as well as the relative position and attitude of the different heads with respect to each other over time needs to be investigated. Also, we are interested in the effects stemming from a combination of the different sub-images to a common so called virtual image and in the overall accuracy of the whole system in object space.
To complete these tasks we look at different scenarios based on the transformation equations from object to image space in terms of analytical computations, computer simulations and practical tests; each result is thoroughly analysed, documented and evaluated.

Results

Final results are not yet available. Initial investigations indicate that in geometric accuracy the DMC will indeed be comparable with many classical aerial cameras.