Influence of spectral characteristics of IR (8-12 mkm) photodetectors on thermovision system parameters

The calculations of noise equivalent temperature difference (NETD) for thermovision devices are carried out, with cut- off wavelengths of photo detectors ((lambda) co) and distance to target used as parameters. For the estimation of influence of the photodiode spectral characteristics on the parameters of thermovision systems several characteristics were taken into account: the spectrum of radiation of object, transmission of an atmosphere and spectral characteristic of sensitivity of photo-diode array. The results show that an increase of (lambda) co above 10.5 microns at small distances improves the temperature resolution in degradation of temperature resolution (increase NETD).