Garmin GPS 155TSO, Owner'S Manual

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The RAIM Prediction function allows you to confirm that GPS coverage is avail-
able for a specific location or waypoint, any day of the year. R eceiver A utonomous
I ntegrity M onitoring performs checks to ensure that the GPS 155 will have adequate
satellite geometry to work with during your flight. RAIM availability will be near
100% in Oceanic, En route, and Terminal phases of flight. Because the FAA’s TSO
requirements for non-precision approaches specify significantly better satellite cover-
age than other flight phases, RAIM may not to be available when flying some
approaches. The GPS 155 will automatically monitor RAIM during approach opera-
tions and warn you if RAIM is not available. RAIM prediction will help you plan for a
pending flight to confirm that the GPS 155 can be used for an approach, and should
be calculated the night before or the day of the desired flight.
To predict RAIM availability:
1. Press
C
and rotate
O
to highlight ‘RAIM Prd?’. Press
E
. The cursor highlight will
appear on the ‘Compute RAIM?’ prompt, ready to compute RAIM for your present position
and time. To compute RAIM, press
E
. If you want to see if RAIM is available at anoth-
er date or time, or at any waypoint in the database, perform steps 2 through 6.
2. Rotate
O
to highlight the field which you would like to change.
3. Use
K
and
O
to enter the waypoint name, or leave it blank to use your current posi-
tion. Press
E
to accept. or :
4. Use
K
and
O
to enter the day/month/year and the estimated time of arrival in hours
and minutes (in local or UTC time, whichever you have selected from the clock display).
The current date will be displayed automatically. Press
E
to accept.
5. Rotate
O
to highlight ‘Compute RAIM?’ and press
E
.
When the computations are complete, the GPS 155 will display whether or not
RAIM is available for the specified date and time, +/- 15 minutes of your ETA.
20
NAV KEY
NAV Menu 2/RAIM Prediction
Confirm the selected waypoint.
Enter the time and date for RAIM prediction.
RAIM available for the entered date & time.
155man (GOOD) 7/24/98 1:56 PM Page 20