Hans Peter Röser 
  
2 AIRBORNE DIGITAL CAMERA REQUIREMENTS 
Up to now film aerial cameras with traditional techniques have normally been used for high precision photogrammetric 
mapping followed by digital scanning for image processing including stereo visualization. By using different films 
these cameras can also be used for remote sensing to some extent. Figure 3 illustrates the typical workflow for the film- 
based process. Extensive research and industrial developments within the last 10 years in CCD technology, computer 
performance and data storage capacity offer the opportunity to replace the film aerial camera for many applications and 
also to improve the quality of the photogrammetric and remote sensing products. 
Revision 
Visual- 
ization 
Image- 
analysis 
Class- 
ification 
  
Figure 3: Film based and direct digital workflow 
To have any chance of an effective impact in a market place governed for decades by high performance film cameras, 
an airborne digital sensor (ADS) must ideally fulfill all the following requirements. 
* Provide a large field of view along and across the flight direction to reduce flight time and cost 
The detector system should have a high sensitivity and a linear response characteristic with high dynamic range 
The size of the CCD elements must enable high spatial resolution 
For multispectral imagery several wavelength channels with suitable bandwidths, including NIR, must be available 
The sensor system should operate with short exposure time and high repetition rates 
Provide a radiometric calibration procedure to guarantee stability of the sensor sensitivity 
Provide stereo capability in flight with one camera only 
* Near real time availability of the data on the ground. 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part Bl. Amsterdam 2000. 253