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Engineering topics

Mosher, J.

Publications and source records attributed to Mosher, J..

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Determination of planetary photometric functions

The determination and removal of the photometric properties of the atmosphere and surfaces of pale planetary objects are of signal importance in the production of planetary mosaics and are themselves important scientific endeavors. The work done at the JPL Image Processing Laboratory in this area in support of the Voyager project is reviewed. Topics discussed include data-base generation, parameter determination, and photometric function removal. The importance of determining the photometric function for a planet in mosaicking together sets of images is stressed. It is noted that techniques have been developed and software has been written to allow scientists to easily determine the parameters to several photometric functions.

Mosher, J.↗
NASA NTRS1980

A color-ratio map of Mercury

Orange and UV frames are used to construct a color-ratio map of the portion of Mercury imaged by Mariner 10, with at least two independent color-ratio images being used for each region in order to prevent spurious, blemish-induced color. Color differences appear to be smaller than those of the moon, and many apparently fresh craters and their ray systems tend to be bluer than their surroundings. Regions of interesting color contrast are noted, and it is concluded that there is little evident correlation of color with either geology or topography.

Hapke, B.↗
NASA NTRS1975

Evidence for non-radial fields in the sun's photosphere and a possible explanation of the polar magnetic signal

The appearance of H-alpha fibrils suggests the presence of magnetic fields inclined at noticeably nonradial angles in the sun's chromosphere. Evidence is presented to suggest that these angles continue into the photosphere. The presence even of small nonradial inclinations can significantly affect the appearance of regions observed by a longitudinal magnetograph. In particular, a simple bipolar loop can appear unbalanced when viewed near the limb. It is suggested that the observed polar signal may be nothing more than a geometric effect arising when a balanced but systematically aligned array of bipolar pairs is viewed at an angle.

Pope, T.↗