Imaging system with integrated measuring of the wear of its optical elements working in transmission mode and optronic imaging equipment comprising an imaging system such as this

An imaging system with integrated measurement of wear in at least one of its optical elements working in transmission mode in a given spectral band, said system including an input optical element, a combination of optical elements and an imaging detector on which there is projected, in imaging mode, an incident beam coming from an observed scene by means of the combination of optical elements, wherein said system comprises:

• means to generate a reference test pattern having a temperature difference defined with precision;
• means for the servo-control of the temperature difference of the reference test pattern, designed to give the imaging detector a known reference modulation transfer rate to the imaging detector, irrespectively of the ambient temperature;
• optical means which, in wear measurement mode, define an optical path designed to form an image of the reference test pattern on the imaging detector through the optical element to be checked;
• means to measure the modulation transfer rate and the rate of transmission of light through the optical element to be controlled on the basis of the variation in the amplitude of the signal given by the imaging detector;
• and alarm means designed to report the presence of an optical element, the degree of wear of which is greater than a critical value.