The Mars Global Surveyor mission
dictionary.
The edit mode is the first pixel of the CCD sampled
for the image acquisition, and thus specifies the off-nadir look
angle. For WA products, the special value 3456 indicates that the
leading dark reference pixels were acquired as the first eight
pixels of each line; the special value 3472 indicates that the
trailing dark reference pixels were acquired as the last eight
pixels of each line. For WA products, if dark pixels were acquired
and compression was enabled, the dark reference pixels are
compressed and included in the data. An edit_mode_id value of "0"
refers to the first pixel in the array.
The instrument_id element provides an abbreviated
name or acronym which identifies an instrument.
Per-line exposure duration in units of milliseconds.
The time a given line was acquired can be determined by multiplying
the line exposure time by the number of previous lines and
adding it to the image start time. Note that the NA implements
downtrack summing by increasing the line time; for example,
a 2X2 summed image has an actual line time twice that given by this
field. Similarly, the gain is adjusted appropriately for summed NA
images; for example, a 2X2 summed image's gain is reduced by a factor
of 2.
The mission_phase_name attribute provides the commonly
used name of a mission phase.
The spacecraft_clock_start_count attribute provides
the value of the spacecraft clock at the beginning of a time period
of interest.
Identifier of the version of the MOC flight software
used to acquire this image.