Measurements of Planetary Radiation at Centimeter Wavelengths

Radiation from the planets, Venus, Mars, and Jupiter, has been measured at a wavelength of 3.15 cm using the Naval Research Laboratory 50-foot reflector and a narrow-band radiometer. The apparent blackbody temperatures for Mars and Jupiter derived from the radio measurements agree reasonably well with the results of infrared radiometric measurements. For the case of Venus, the apparent blackbody temperature derived from the 3.15-cm measurements is about a factor of two higher than the value derived from the infrared measurements. A measurement of the radiation from Venus at 9.4-cm wavelength was made using the same antenna. The apparent blackbody temperature derived from this measurement agreed well with the value derived from the 3.15-cm measurement, but the accuracy of the 9.4-cm result was low because of the small flux density of radiation and the small number of observations.