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Chase, S. C., Jr.

Publications and source records attributed to Chase, S. C., Jr..

14 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Viking infrared thermal mapper

The infrared thermal mapper (IRTM) was designed to measure the emitted and reflected radiance of Mars. Carried by the Viking Orbiter, the IRTM contains four small Cassegrainian telescopes which each image the same, seven circular areas. There is a total of twenty-eight channels in four surface and one atmospheric thermal bands from 6 to 30 microns and a broad solar reflectance band. All channels are sampled simultaneously, using the spacecraft scanning capability to map the radiance over small and large areas of the planet. All channels use thermopile detectors; spectral passbands are determined by a combination of interference filters, detector lense materials, antireflection coatings, and restrahlen optics.

Chase, S. C., Jr.↗
NASA NTRS1976

Martian north pole summer temperatures - Dirty water ice

Broadband thermal and reflectance observations of the Martian north polar region in late summer yield temperatures for the residual polar cap near 205 K with albedos near 43 percent. The residual cap and several outlying smaller deposits are water ice with included dirt; there is no evidence for any permanent carbon dioxide polar cap.

Kieffer, H. H.↗
NASA NTRS1976

Infrared thermal mapping of the Martian surface and atmosphere - First results

The Viking infrared thermal mapper measures the thermal emission of the Martian surface and atmosphere and the total reflected sunlight. With the high resolution and dense coverage being achieved, planetwide thermal structure is apparent at large and small scales. The thermal behavior of the best-observed areas, the landing sites, cannot be explained by simple homogeneous models. The data contain clear indications for the relevance of additional factors such as detailed surface texture and the occurrence of clouds. Areas in the polar night have temperatures distinctly lower than the CO2 condensation point at the surface pressure. This observation implies that the annual atmospheric condensation is less than previously assumed and that either thick CO2 clouds exist at the 20-kilometer level or that the polar atmosphere is locally enriched by noncondensable gases.

Kieffer, H. H.↗
NASA NTRS1976

Mariner 10 infrared radiometer results - Temperatures and thermal properties of the surface of Mercury

Mariner 10 infrared brightness temperatures of the surface of Mercury at 11 and 45 microns are presented. The data were obtained during the first flyby along a near-equatorial swath extending from 17 hours local time through local midnight to 9 hours local time. For an assumed emissivity of 0.9, derived surface thermal inertias are between 0.0015 and 0.0031 cal/sq cm/sq root sec/K and the implied minimum predawn surface kinetic temperature for the warm pole at longitude 270 deg is near 93 K. Several pronounced thermal inhomogeneities were seen, one of which appears to coincide with a region of high radar reflectivity. The derived thermal properties, the electrical skin depth, and loss tangent fall within the range of values found on the moon.

Chase, S. C., Jr.↗
NASA NTRS1973

Preliminary report on infrared radiometric measurements from the Mariner 9 spacecraft.

Preliminary 10- and 20-micron brightness temperatures of Mars are presented. More than 35% of the Martian surface was observed with a resolution better than 100 km. On the whole, the results confirm the thermal properties derived from the Mariner 6 and 7 radiometers, although the temperatures, on the average, were cooler and shifted with respect to the Martian day during the dust storm. Thermal inertias and radiometric albedos were derived for many areas; no clear correlation exists between these properties. Thermal structure again was found at the spatial limit of the radiometer; no cases were found in which it was necessary to invoke internal heat sources.

Kieffer, H. H.↗
NASA NTRS1972

Infrared thermal mapping experiment - The Viking Mars Orbiter.

The Mars infrared thermal mapper (IRTM) will be carried on the scan platform of the orbiter of the Viking 1975 mission. The IRTM is a multichannel radiometer with several detectors in each of six spectral regions. The spectral channels are selected to be sensitive to surface emissivity variations and provide good temperature resolution over the entire range of Martian temperatures. These observations will allow determination of the surface kinetic temperature and thermal balance, and by coverage of the dark hemisphere, a search for regions with anomalous cooling can be made. Observations of ground frosts or clouds will help to determine their composition, and in the case of extensive H2O frosts, will allow the local water vapor pressure to be estimated.

Kieffer, H. H.↗
NASA NTRS1972

Infrared radiometry experiment on Mariner 9.

A two-channel IR radiometer similar to that carried on Mariners 6 and 7 was included on Mariner 9 in order to extend and improve the surface coverage and spatial resolution obtained on the earlier flights. The minimum brightness temperature observed by the Mariner 9 radiometer over the shrinking south polar cap, slightly after Martian southern midsummer, is at least 25 K above the temperature that would correspond to frozen carbon dioxide.

Chase, S. C., Jr.↗
NASA NTRS1969

Infrared radiometry

Mariners 6 and 7 infrared radiometer measurements on energy spectrum of Mars

Chase, S. C., Jr.↗