Receiver (noise) temperature

From Glossary of Meteorology

receiver (noise) temperature

A measure of the noise power density at the output of a radio or radar receiver due to internally generated noise and passive losses in the receiver. In particular, the receiver temperature Tr is the temperature of a resistor having noise power per unit bandwidth equal to that of the receiver output at a given frequency.

It is given in terms of the power output P and bandwidth B of the receiver by Tr = P/kB, where k denotes Boltzmann's constant, 1.38 × 10-23J K-1. The receiver temperature is related to the receiver noise factor F by Tr = To(F - 1) with To = 290 K.
See noise temperature, noise figure.