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190-00607-02 Rev C
Detailed Operation
Terrain (TER) Function
The Terrain Function shows a map of the terrain
in the area relative to your airplane’s position and
altitude. The GMX 200 has a standard internally based
terrain function. The GMX 200 also supports an exter-
nal TAWS sensor. When the external TAWS sensor is
connected, it replaces the GMX 200’s internal Terrain
function.
Terrain information can be supplied by one of two
sources:
•
Internal GMX 200-Based Terrain
•
External TAWS-Based Terrain
Review the Limitations section in the front of this
guide for the limitations that apply to the terrain data.
Internal GMX 200-Based terrain
The altitude information comes from an external
altitude encoder or GPS altitude depending on your
installation. For pressure altitude, displayed altimeter
setting has to be adjusted, or baro-corrected, just like
the one in your aircraft’s instrument panel.
Terrain Page with GMX 200-Based Data
The terrain screen has a 360-degree and a 120-
degree display. Both screens will show terrain relative
to your position. Colors used for terrain display are
shown below.
1000 feet below your
current altitude
Ye
llo
w
2000 feet below your
current altitude
B
la
ck
R
ed
G
re
en
Current Altitude
Highest Terrain
More than 2000 feet
below your current altitude
1
below or at
your current altitude
00 feet
Above your current altitude
R
ed
Terrain Elevation Color Coding Reference
(Normal Terrain Model)
NOTE:
The Terrain function shows you the gen-
eral terrain elevations relative to your altitude
and are advisory in nature. Individual obstructions
may be shown if available in the database. Terrain
is displayed from database information and may
therefore potentially contain some degree of er-
ror. Do not use this information for navigation.
obstructions
Obstructions, such as towers and other man-made
objects, are part of the GMX 200 updateable database.
Obstructions over 250 feet high are shown on the maps
with tower symbols. The symbol is color coded to sig-
nify the relative altitude of the tower to your aircraft’s
altitude and follows the same conventions as the color
coding for terrain.
Obstruction icons
Objects that are at your altitude are shown in red;
objects that are near your altitude are shown in yellow;
objects with towers that are significantly below your
altitude colored green. Obstructions are shown on the
Terrain
