Worlds of David Darling
Encyclopedia of Science
   
Home > Encyclopedia of Science

antenna temperature




In radio astronomy, a measure of the power per unit bandwidth (p) of the signal received by an antenna after losses in the detector system. It is defined as p/k, where k is Boltzmann's constant.

In an ideal, loss-free radio telescope, the antenna temperature is equal to the brightness temperature if the intensity of the received radiation is constant within the main lobe. If the angular dimension of the source is small compared to the main lobe, the antenna temperature is equal to the brightness temperature multiplied by the ratio of the solid angle subtended by the source to the effective solid angle of the antenna.


Related category

   • RADIO ASTRONOMY AND COMMUNICATIONS