Legend:

Sphere plot(s): show(s) Iapetus as seen from Cassini
Grid lines Grid information is longitude degrees west
Areas covered by blue dots Terrain of Iapetus not illuminated by the sun.
The blue line marks the terminator (day/night boundary)
NAC/WAC field of view Field(s)-of-view of the ISS NAC and/or WAC

Map plot(s): show(s) a cylindrical map including the field-of-views of the ISS NAC and/or WAC as planned to be observed during the flyby. The global map is centered at the sub-Saturn point (0N, 180W). The surface map is courtesy of Steve Albers (NOAA).
Horizontal axis Surface longitude in degrees west.
Vertical axis Surface latitude in degrees north and south.
Areas shown at high contrast Terrain illuminated by the sun and visible by Cassini at this time.
Areas shown at low contrast Terrain not illuminated by the Sun, but visible to Cassini. Note that parts of this area might be illuminated by saturnshine.
The blue line marks the terminator (day/night boundary)
Areas shown in dark gray Terrain not visible to Cassini, because it is behind the horizon.
The yellow line marks the limb (horizon).
NAC/WAC field of view Field(s)-of-view of the ISS NAC and/or WAC
S/C Sub-spacecraft point (an observer on the surface would see Cassini exactly in the zenith direction)
S5P Sub-solar point (an observer on the surface would see the sun exactly in the zenith direction)