AN EXPERIMENTAL INVESTIGATION OF LUNAR AND AURORAL SCATTERED SIGNALS. PART 1 LUNAR ECHOES

An experimental investigation of lunar echoes at 915 mc has been conducted. The transmission loss between isotropic radiators over the earth-moon-earth path was established as being 280 dbAT 915 MC. This result, in conjunction with transmission losses reported by other investigators in the frequency range from 200 mc to 3000 mc, leads to the conclusion that the radar cross section of the moon is frequency dependent and decreases with increasing frequency at a rate of about 6 db per octave. At 915 mc, the lunar radar cross section was equal to 4.2 x 10 to the 10th power square meters. After detection, the lunar echo at 915 mc exhibits Rayleigh-like fading with an average 10- to 90-percent fading range of about 14 db. There is evidence that the lunar echo is not entirely randomly phased but contains a steady-signal component which is in the ratio of 1.5 to 1 with the rms scattered-signal components, i.e. 47 percent scattered power and 53 percent specular reflected power.