MESS MDIS MAP PROJ HIGH-INCIDENCE BASEMAP EAST RDR V1.0

The HIE data set is a companion to the Map Projected High-Incidence Angle Basemap Illluminated from the West RDR (HIW) data set. Together the two data sets are intended to detect and allow the mapping of subtle topography. They complement a Basemap Data Record (BDR) data set also composed of WAC filter 7 and NAC images acquired at moderate/high solar incidence angles centered near 68 degrees (changed to 74 degrees in the final end-of-mission data delivery), and a Low Incidence Angle (LOI) data set also composed of WAC filter 7 and NAC images acquired at lower incidence centered near 45 degrees, analogous to the geometry used for color imaging.

The map is divided into 54 'tiles', each representing the NW, NE, SW, or SE quadrant of one of the 13 non-polar or one of the 2 polar quadrangles or 'Mercury charts' already defined by the USGS. Each tile also contains 5 backplanes: observation ID; BDR metric, a metric used to determine the stacking order of component images, modified for the higher incidence angle centered near 78 degrees; solar incidence angle; emission angle; and phase angle.