Remote sensing geophysics from Skylab
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Engineering topics
Publications and source records attributed to Watson, K..
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An analysis was made of Nimbus satellite data to determine its suitability in determining the physical properties of surface materials. Attempts were also made to use these data in developing analytical techniques for handling data from other earth resources and meteorological satellites.
Results obtained through the NASA Earth Resources Aircraft Program at Mill Creek, Oklahoma, provide a case history example of the application of remote sensing to the identification of geologic rock units. Thermal infrared images are interpreted by means of a sequence of models of increasing complexity. The roles of various parameters are examined: rock properties (thermal inertia, albedo, emissivity), site location (latitude), season (sun's declination), atmospheric effects (cloud cover, transmission, air temperature), and topographic orientation (slope, azimuth). The results obtained at this site also illustrate the development of an important application of remote sensing in geologic identification. Relatively pure limestones and dolomites of the Mill Creek test area can be differentiated in nighttime infrared images, and facies changes between them can be detected along and across strike. The predominance on the earth's surface of sedimentary rocks, of which limestone and dolomite are major members, indicates the importance of this discrimination.
Spectral reflectance and thermal emission data were collected at the Mill Creek, Oklahoma test site during NASA missions 132 and 133 in June 1970. The data were collected by three aircraft flown several times during the diurnal cycle at altitudes of 150 to 17,000 m above mean terrain. Reflectance of the main rock types (limestone, dolomite, and granite) was determined from the data collected using a 12-channel multispectral scanner during mission 133 and from thermal infrared images recorded during mission 132 on an RS-7 scanner from 17,000 m above terrain. A preliminary rock recognition map was generated automatically using data collected from 900 m above terrain. The discrimination provided by the map is reasonably accurate. Misidentification occurred in areas of unusually high dolomite reflectivity. High altitude thermal infrared (10 to 12 micrometers) images show regional folds and faults distinguished by the presence of thermally contrasting materials. Linear and curvilinear structural features two to three times smaller than the nominal 17 m resolution could be detected.
A mathematical model derived from the equation of heat conduction was developed to assist in interpreting thermal infrared images acquired from aircraft and spacecraft. The model assumes steady state boundary conditions. It contains parameters of rock and soil properties, atmospheric effects, site location, and season. The results predicted provide an explanation for the thermal differences among granite, limestone, and dolomite recorded in the December 1968 daytime and predawn flights over the Mill Creek, Oklahoma test site, during which representative thermal inertia and albedo values were used. A second test of the model made use of data acquired during the June 1970 predawn overflight of Mill Creek. A simple model of transient heating of the ground was constructed as an extension of the overall model, in order to examine the effects of atmospheric perturbations. The results obtained are consistent with those of ground observations made at the time of the overflight.
Thermal and infrared imagery of Mill Creek Area, Oklahoma
Wall vibrations and amplitude attenuations measured in tunnel and cavity formed by underground nuclear explosion
Thermal conductivity of powders in vacuum from 120 to 350 degrees k, measured by an apparatus enclosed in a sand-cast aluminum vacuum chamber
Apparatus for measurement of thermal conductivity of powders in vacuum from 120 to 350 deg. k.
Lifetimes of ices of common volatiles /water, carbon dioxide, methane/ in solar system
Study of the stability of volatile ices in short period comet orbits, on the surfaces of jupiter and saturn major satellites, and saturn rings
Possible presence of local concentrations of ice on moon in permanently shaded areas