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Shorthill, R. W.

Publications and source records attributed to Shorthill, R. W..

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Apollo experiment S-217 IR/radar study of Apollo data

An experiment using Earth based remote sensing radar, infrared eclipse, and color difference data to deduce surface properties not visible in Apollo photography is reported. The Earth based data provided information on the small scale (centimeter sized) blockiness and on the surface chemical composition (titanium and iron contents) of the lunar surface. These deduced surface properties complemented the new Apollo photography, leading to refined geologic interpretations of the lunar surface.

Thompson, T. W.↗
NASA NTRS1976

The 'soil' of Mars /Viking 1/

The immediate environs of the Viking 1 lander are described, and the techniques employed to deduce the properties of the two different 'soil' types there are summarized. It is shown that the surface in the immediate vicinity of the lander consists of an area with fine-grained materials ('Sandy Flats') and a rocky area set in a matrix of finer-grained material ('Rocky Flats'). Estimates are given for the bulk density, particle density, particle size distribution, cohesion, angle of internal friction, and penetration resistance of the surface layer in each area. Footpad penetration into the surface layer is discussed, and wind removal of particles is examined. It is concluded that the surface layer of the Viking 1 landing site contains loess, dune sand, lunar nominal soil, lag gravel, and bare rock.

Shorthill, R. W.↗
NASA NTRS1976

Physical properties of the Martian surface from the Viking 1 lander - Preliminary results

Examination of the erosion of the surface of Mars caused by the descent engines of the Viking 1 lander indicates that the soil is stronger and/or denser than the 'lunar nominal' soil (an artificially produced soil with a particle size distribution similar to results for lunar soils obtained by Apollo 11) used in preflight site alteration tests. There is further evidence to suggest that the finer grains are not as small as those of the lunar nominal material, and that the soil under the lander footpads is relatively stiff. The crater, depressions, and ejecta associated with the impact of a latch pin which fell from the surface sampler are consistent with terrestrial soils with very low cohesions, small grain size, and a density of 1.2 to 1.7 g/cu cm.

Shorthill, R. W.↗
NASA NTRS1975

The spectral reflectivity of select areas on Europa

The July 12, 1973, occultation of Europa by Io was observed in 30 wavelength channels in the spectral region between 3200 and 11,000 A with the 200-inch Hale telescope and a multichannel spectrometer. The data are presented in absolute units above the earth's atmosphere and are analyzed to obtain the spectral reflectivity of seven localized areas on the disk of Europa centered on 324 deg W longitude. The equatorial material is confirmed to be darker than the eastward-skewed bright north polar cap and a hint is evident that the darker material may be somewhat redder than the cap material.

Greene, T. F.↗
NASA NTRS1974

A comparison of infrared, radar, and geologic mapping of lunar craters

Between 1000 and 2000 infrared (eclipse) and radar anomalies have been mapped on the nearside hemisphere of the moon. A study of 52 of these anomalies indicates that most are related to impact craters and that the nature of the infrared and radar responses is compatible with a previously developed geologic model of crater aging processes. The youngest craters are pronounced thermal and radar anomalies; that is, they have enhanced eclipse temperatures and are strong radar scatterers. With increasing crater age, the associated thermal and radar responses become progressively less noticeable until they assume values for the average lunar surface. The last type of anomaly to disappear is radar enhancement at longer wavelengths. A few craters, however, have infrared and radar behaviors not predicted by the aging model. One previously unknown feature - a field strewn with centimeter-sized rock fragments - has been identified by this technique of comparing maps at the infrared, radar, and visual wavelengths.

Thompson, T. W.↗
NASA NTRS1974

Mare Serenitatis - A preliminary definition of surface units by remote observations

Mare Serenitatis is a ringed mare about 600 km in diameter situated in the northeast quadrant of the moon. The floor of the mare is comprised of several units. Remote observations of Mare Serenitatis are presented. Color difference photographs were produced by photographing the moon at two wavelength bands. Radar images were obtained by delay-Doppler mapping of radar echoes. The definition of surface units is discussed together with surface properties obtained from remote observations.

Thompson, T. W.↗
NASA NTRS1973

Infrared atlas charts of the eclipsed moon.

The objective of this atlas is to present the thermal response of the lunar surface observed during an eclipse of the moon with accurate position data. The observations were made at a wavelength of 11 microns with an angular resolution of 10 sec, equivalent to 17 km at the disk center. Over a thousand thermally anomalous regions (hot spots) were detected. They cool more slowly than their environs and remain warmer than their environs during the umbral phase. In addition to these very localized hot spots, some of the maria show thermal enhancements during the eclipse. Fourty four charts make up this atlas which are identical in coverage and projection to the Lunar Atlas Charts (LAC) series. The charts are in the form of digital images of a normalized temperature difference which is particularly useful for studying regions of small thermal enhancements. Each increase of intensity corresponds to a 4 K temperature increase.

Shorthill, R. W.↗
NASA NTRS1973

Remote sensing of Mare Serenitatis

An examination was made of earth based observations of optical color differences, infrared eclipse temperatures, and radar backscatter for Mare Serenitatis. Information is also included on orbital observations, physical properties of surface types, and correlation of surface types with geologic units. Differences in these remote observations are attributed to variations in chemical and minerological compositions.

Thompson, T. W.↗
NASA NTRS1972

Jovian satellite eclipse study 2 eclipse data

The Jove satellite eclipse observations performed on April, 8 May, and 13 May, 1972 with the 200-inch Hale Telescope are reported. Spectrograms, and multichannel spectrometer data are included.

Greene, T. F.↗
NASA NTRS1972

Apollo 16 landing site: Summary of earth based remote sensing data, part W

Infrared and radar studies of the Apollo 16 landing site are summarized. Correlations and comparisons between earth based remote sensing data, IR observations, and other data are discussed in detail. Remote sensing studies were devoted to solving two problems: (1) determining the physical difference between Cayley and Descartes geologic units near the landing site; and (2) determining the nature of the bright unit of Descartes mountain material.

Zisk, S. H.↗
NASA NTRS1971

Jovian satellite eclipse study. 1: 1971 eclipses

Observations of five Jovian satellite eclipses were obtained during February, March, and April 1971 with the 200-inch Hale telescope and multichannel spectrometer. Eclipse light curves in 20 wavelength bandpasses were obtained for each eclipse.

Greene, T. F.↗
NASA NTRS1970

Eclipse cooling of selected lunar features

Thermal measurements were made in the 10 to 12 micron band of the lunar surface during the total eclipse of December19, 1964. A normalized differential thermal contour map is included, showing the location of the thermal anomalies or hot spots on the disk and the eclipse cooling curves of 400 sites, of which more than 300 were hot spots. The eclipse cooling data is compared to a particulate thermophysical model of the soil.

Shorthill, R. W.↗