Engineering topics

Peeples, W. J.

Publications and source records attributed to Peeples, W. J..

4 records

NASA NTRS1978

Orbital radar evidence for lunar subsurface layering in Maria Serenitatis and Crisium

Data from the lunar-orbiting Apollo 17 radar sounding experiment (60-m wavelength) have been examined in both digital and holographic formats, and it is concluded that there are two subsurface radar reflectors below the surface in Mare Serenitatis and one reflector below the surface in Mare Crisium. The mean apparent depths of the reflectors below the surface of the former Mare are 0.9 and 1.6 km, while the reflector below the surface of the latter Mare has a mean depth of 1.4 km. These reflectors represent basin-wide subsurface interfaces. Techniques for reducing surface backscatter (clutter) in the data are described, and reasons for thinking that the distinct alignments in radar returns represent subsurface reflecting horizons are explained

Peeples, W. J.↗

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.↗

NASA NTRS1973

Apollo lunar sounder experiment

The four basic data products from the ALSE are sounding, profiling, imaging, and noise measurements. Attention was concentrated on the first three products, and both theory and preliminary results are presented. Background information is presented on the experiment and on the data products. Preliminary examples of the types of analyses that can be performed and the conclusions to which they can lead are included. Preliminary analysis of the data for subsurface features was successful in indicating with a high probability the capability of the ALSE to achieve its fundamental goal of substrate sounding. The imagery and profiling data are useful immediately for geologic interpretation, as demonstrated.

Phillips, R. J.↗

NASA NTRS1973

The Apollo 17 Lunar Sounder

The Apollo Lunar Sounder Experiment, a coherent radar operated from lunar orbit during the Apollo 17 mission, has scientific objectives of mapping lunar subsurface structure, surface profiling, surface imaging, and galactic noise measurement. Representative results from each of the four disciplines are presented. Subsurface reflections have been interpreted in both optically and digitally processed data. Images and profiles yield detailed selenomorphological information. The preliminary galactic noise results are consistent with earlier measurements by other workers.

Phillips, R. J.↗