This article is devoted to the issues of remote sensing of natural surfaces in order to determine their temperatures by their own radiation in the infrared (IR) region of the spectrum. The basics of the radiometric method are briefly described, the factors influencing the result of remote measurements are analyzed. A formula is obtained by which the influence of ambient radiation (background) reflected from the studied surface on the result of thermodynamic temperature measurement is calculated. The calculation takes into account the emissivity of the reference black body, according to which the IR radiometer was calibrated, the background radiation temperature during calibration of the device and is performed for two spectral ranges located in the transparency window of the atmosphere. The calculation results are relevant for improving the accuracy of remote sensing of temperature fields of natural objects.

Keywords: remote sensing, IR radiation, IR radiometer, temperature field, energy brightness, background radiation, blackbody, optical flux, radiation temperature, emissivity