VIA Technologies EPIA SN-Series Specifications download pdf (Page 32)

Remote Sensing and Photogrammetry, State of the Art Technologies

Instead of using an RGB filter to achieve colour registration, cameras can also be

equipped with three separate CCDs in conjunction with an optical beam splitter. This

solution avoid the interpolation necessary using a Bayern filter enabling higher spectral

performances. Systems made by Airborne Data System and Integrated Spectronics utilize

this simultaneous method to acquire the Red, Green and Blue spectral bands.

The New Metric Camera made by the VTT research institute in Finland utilizes nine

squared CCDs in its focal plane (pixel pitch 4 µm). The individual image produced by the

CCDs array is approximately 10000 pixels (in the across-track direction) x 1600 pixels

(in the along-track direction). This solution, called multiple arrays camera, is also used by

the G2010 camera developed by Global Imaging Technologies but in this case each CCD

is coupled with its lens while in NMC a single lens for entire set of detectors is used.

Another adopted technical solution is the use of multiple cameras put together in a

unique assembly. The multiple camera approach can be used to acquire colour or false

colour images; three to four monochrome cameras are coupled, with their optical axis

parallel to one another and their shutter synchronized to operate simultaneously to cover

the same target area. To produce the final image different spectral bands are fused

together to generate a colour image. An example is the ADS Agri-View with four small

format cameras acquiring the Red, Green, Blue and nIR bands.

Using multiple cameras it is possible to acquire oblique images like the the Track‟Air

MIDAS system which makes use of five Canon EOS 1D used to acquire one vertical and

four oblique colour photos simultaneously. Oblique images produced by these systems

are very useful in 3D building reconstruction because the camera is able to see vertical

side of constructions.

Figure 21:ADS Agri-View multispectral camera [Ref. (7)] and Track’Air oblique MIDAS system

[Ref. (8)]

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VIA Technologies EPIA SN-Series Specifications Page 32