Page "learned" Paragraph 11

The observations of Mayer, McCullough, and Sloanaker at 3.15 cm and of Sloanaker at 10.3 cm have not previously been published and will be briefly described.

Measurements at 3.15 cm were obtained on 11 days spread over the interval May 3 to June 19, 1956, using the 50-foot reflector at the U. S. Naval Research Laboratory in Washington.

The half-intensity diameter of the antenna beam was about 9', and the angle subtended by the moon included the entire main beam and part of the first side lobes.

The antenna patterns and the power gain at the peak of the beam were both measured ( Mayer, McCullough, and Sloanaker, 1958 ), so that the absolute power sensitivity of the antenna beam over the solid angle of the moon was known.

The ratio of the measured antenna temperature change during a drift scan across the moon to the average brightness temperature of the moon over the antenna beam ( assuming that the brightness temperature of the sky is negligible ) was found, by graphical integration of the antenna directivity diagram, to be 0.85.

The measured brightness temperature is a good approximation to the brightness temperature at the center of the lunar disk because of the narrow antenna beam and because the temperature distribution over the central portion of the moon's disk is nearly uniform.

The result of the observations is Af where the phase angle, Q, is measured in degrees from new moon and the probable errors include absolute as well as relative errors.

This result is plotted along with the 8.6-mm observations of Gibson ( 1958 ) in figure 1, A.

The variation in the 3-cm emission of the moon during a lunation is very much less than the variation in the 8.6-mm emission, as would be expected from the explanation of Piddington and Minnett ( 1949 ).

In the discussion which follows, the time average of the radio emission will be referred to as the constant component, and the superimposed periodic variation will be called the variable component.