Garmin GPS 150 Pilot's Manual page 75

The Receiver Status field can display the following messages:
Search Sky - The GPS 150 is searching the sky for visible satellites. You will
be informed with the message 'Searching the sky'.
Acquiring - The GPS 150 is acquiring satellites for navigation.
2D Nav - The GPS 150 is in 2D navigation mode. If your installation
does not include an altitude serializer, you must enter the alti-
tude manually.
3D Nav - The GPS 150 is in 3D navigation mode and will compute
altitude.
Simulator - The GPS 150 is in simulator mode, which should only be used
for practice and trip planning. NEVER use simulator mode for
actual navigation.
Poor Cvrge - The GPS 150 cannot acquire sufficient satellites for navigation.
Need Alt - The GPS 150 needs altitude in order to start/continue naviga-
tion. Select the Position page and enter the altitude. (See
Section 1 for more information.)
Not Usable - The GPS 150 is unusable due to incorrect initialization or
abnormal satellite conditions. Turn the unit off and back on
again. If this does not help, contact an authorized GARMIN
dealer for service.
REFERENCE
Receiver Status Messages
Section
5
65