V.V. Tikhonychev, Yu.G. Veselov, A.A. Danilin
In digital aerophotography systems (DAS), matrix photosensitive charge-coupled devices, which have a regular structure and a given element size, are used as a receiver of optical radiation. Using such receiver of optical radiation makes the main difference of DAS from aerial cameras in which an aerolandscape image is recorded on an aerofilm.
Using DAS without an image shift compensation system the image moves relative to the receiver of optical radiation thanks to the movement of the carrier.
In the article, expressions for the modulation transfer function of DAS are obtained taking into account the size of the ma-trix receiver element and the size of the longitudinal image shift.
Formulating the equations, the line spread function was defined as a response of the system to the one-dimensional optical delta-function, then the optical transfer function and the modulation transfer function were also defined.
Three variants of the image shift during the exposure time at the constant speed of image in the plane of the radiation re-ceiver:
- the shift is less than the radiation receiver element size;
- the shift equals to the integers of radiation receiver elements;
- the shift does not equal to the integers of radiation receiver elements.
The obtained modulation transfer function allows to the update the mathematical model of DAS.
The work is supported by the Russian fund of basic researches the project 08-08-00613.