Improvement of Calculating Medical Thermovision Camera Minimum Resolvable Temperature Difference

The paper is devoted to improvement of the equation for calculating the minimum resolvable temperature difference (MRTD) of medical thermovision camera by means of more sophisticated models of thermal images visual perception. An MRTD calculating algorithm, which is based on a more reliable approximation of the visual system modulation transfer function by Schultz, is considered. We obtain new expression for the bandwidth of Schultz’s approximation, which does not depend on the angular size of the Foucault pattern bar. An improved equation for calculating the MRTD was obtained. Analysis of the equation has showed that it coincides with the well-known equations for Foucault pattern bar with appointed angular size. The limits of validity of this equation in the visual system spatial integration from 1 to 5,7 arc. minute were determined. An example calculation for Thermal Eye TSC Imager MRTD was fulfilled. There were received two differing analytical MRTD equations, which use Schultz and Lloyd approximations. It is shown that these equations coincide with each other when pixel angular size of microbolometer matrix is equal to 0,71 mrad.
Keywords: medical thermal imager, minimum resolvable temperature difference, modulation transfer function.
Fig. 4. Refs.: 6 titles.

Publication year: 
2014
Issue: 
5
УДК: 
621.384.3
С. 96–100., Іл. 4. Бібліогр.: 6 назв.
References: 

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