Characteristics of the thermal radiation of nonisothermal regions

Methods for the determination of temperatures of objects in circumterrestrial space using a multispectrum IR-radiometer against cold space background

“…It follows from relation (2) and expression for B λ in Eq. (1) that, in the case of significant dependence of…”

“…First of all, it is necessary to make clear whether it is possible to determine the thermodynamic temperature of one of the so-called pseudotemperatures (for example, color or brightness temperature [1]). In addition, at the initial stage of investigations, the temperature of only nonisothermal objects may be measured, because the radiation spectrum of nonisothermal objects with even ideally black surfaces differs from that of bodies with a uniform surface temperature [2].…”