0 0 NOMINAL - ALTITUDE AND EPHEMERIS DATA AVAILABLE
1 1 MISSING AT MOST A SMALL GAP OF ALTITUDE AND EPHEMERIS DATA
2 2 MISSING MORE THAN A SMALL GAP OF ALTITUDE AND EPHEMERIS DATA, BUT NO MORE THAN A GRANULE BOUNDARY
3 3 MISSING MORE THAN A GRANULE BOUNDARY OF ALTITUDE AND EPHEMERIS DATA
15 15 MISSING
