The Starbase One Astronomy & Space Collection/STARBASE_ONE.ISO/images/planets/saturn/tmap.txt

Text File | 1994-11-13 | 2KB | 28 lines

Mercator map of Titan

The latitude ranges from 40 deg South to 50 deg North, the longitude from
0 to 0, with 180 in the center. The grid is 10 deg in latitude and 45 in
longitude. The sub-Saturn point is at 0 E, 7 N.

This map was made from the 14 F850LP fimages of Titan, which are primarily
sensitive to the 0.94 micron methane window. At the beginning of our
obsering period, the sub-Earth longitude was about 120 deg. The first
seven images were taken approximately every seven hours, and will be used
to attempt to locate and track clouds in a sort of Titanian weather movie.
During the time these first seven images were taken, the large bright
feature slowly moved off of the observable disk. The next seven images
were spaced about every 32 hours and gave us near complete coverage of the
surface, with the exception of a 96 hour gap centered near 10 deg. The
bright feature re-appeared in the last two images.

To make the map, the haze background was subtracted from each image. The
resulting images were individually projected onto a map, and they were
then averaged to make what you see. Maps made from even iand odd images in
the sequence were compared against each other to verify that the larger
and brighter features are all real, that is, observed in multiple images.
Some of the brightness may be from clouds, and the smaller and less
contrasty "features" are likely to be noise. Signal to noise in the
original images was ~200:1, and the range of contrast shown is plus or
minus ~5% from the mean.