The radiometric quality of a digital image sensor is given by the signal to noise ratio of pixel, which is defined by the number of signal electrons divided by the number of noise el (Theuwissen, 1995) The number of signal electrons be specified in terms of the number of photons impinging on the sensor po (hv) photon can Apbel, the quantum flux/energy of a single photon), the pixel area efficiency n and the integration time Tint Signal The number of noise electrons can be split up into three main noise sources photon shot noise, equal to the square root of the number of signal electrons, given by lil noise electrons generated in the CCD channels (e.g. incomplete transfer, shot noise on dark current, fixed-pattern noise all summed in n output amplifier noise nout thus the number of noise electrons can be written as Noise n +n [2] If all these contributions are put in the definition of S/N, this yields [3] For normal light levels the noise is dictated by the amplifier noise, fixed read out pattern noise and of the CCD. Fixed pattern noise minimised by the radiometric correction of the individual pixel sensitivity. The signal is thus linear depending on the incoming photon flux Do (light shows, the integration and the area of the CCD-pixel itself. This linear functional relation not be that for best performance of the CCD the exposure time (defined by the integration) must chosen to short, it needs to be adapted to approximately half the saturation level for optimum radiometric resolution of the system. Since the forward motion compensation feature of the DMC allows free choice of the exposure time, optimum illumination conditions for the CCD can be independent from the v/h ratio of the photo flight The CCD size is 144 um2 (12umx12Hm) which is considerable larger (factor 3.5) than a typical line sensor of 42um2 (6.5umx6.5um), thus enabling 12 bit radiometric resolution of the system