Originally Posted by
dervish
..Honeywell seem at pains to point out the database is supplied by someone else, but on their website claim it is proprietary to themselves.
All I can find in the manual (2012 version) is this:
"The terrain database is the heart of the EGPWS. The database includes information regarding terrain, airports
and obstacles such as towers, buildings and antennas, that are 100 ft or taller. It is important to know that
wires are not a part of the database at this time.
The system compares aircraft position and motion against the terrain and obstacle database to provide its
cautions and warnings. EPWS also provides non-database related warnings. It does so using a term known
as geometric altitude, which is derived from radar altitude, a GPS altitude, barometric pressure and aircraft
motion calculations"