Kobrick, M. — Page 3

NASA NTRS1976

Local lunar topography from the Apollo 17 ALSE radar imagery and altimetry

The Apollo 17 ALSE (Apollo Lunar Sounder Experiment) VHF radar provided imagery and continuous profiling data around the moon during two revolutions. The imagery data are used to derive depth and diameter measurements of small craters (diameters less than 30 km). The profiling data are used to study the topography of a few large craters: the bulged floors in Hevelius, Neper, and Aitken; central peaks in Neper and Buisson; and the depressed floor of Maraldi. The same data provided accurate (better than 25 m) profiles of Mare Crisium and Mare Serenitatis.

Elachi, C.↗

NASA NTRS1974

Elevation profiles of the moon

Five MHz radar data obtained from the Apollo 17 mission are used to determine elevation profiles of the moon. A change in range of one quarter of a wavelength (15 m for the 5 MHz radar) changes the round-trip radar range one half wavelength or 180 deg, thus allowing determination of the relative surface profile or slope with a high degree of precision. The technique of deriving the range or altimetry measurement from the range-Doppler data record on film yields a better understanding of the range accuracy. The presence of fade intervals can be observed directly and their effect on the profile measurement reduced to a minimum. The maria used to generate the center of maria are Western Procellarum, Serenitatis, and Crisium. The location of the center of mare relative to the center of figure and center of mass is identified.

Brown, W. E., Jr.↗