Garmin GPS 55AVD - Manual (Page 17)

3-1
CHAPTER 3
BASIC OPERATION
3.1 POWER ON
After you turn your GPS 55 on, it will conduct a series of self tests and display
the following notices: “VER x.xx”, “COPYRIGHT”, “1992”, and “GARMIN”.
Following completion of the tests, the Database Page, which indicates the
database version (Americas vs International), effective date, and expiration
date will now be displayed.
Database Version
Effective
Date
Expiration
Date
The GPS 55 will still function with a database which is out of date; however,
you must exercise extreme caution and always verify that the database
information is correct before use. (Warning: The accuracy of the database
information is assured only if the database is current. Pilots using an out-of-
date database do so entirely at their own risk.) After you press ENT to
approve the database, the GPS 55 will begin acquiring satellites. This
process is fully automatic and typically will take two minutes to obtain a
position fix.
Initially, the GPS 55 will display the “ACQ” banner; it will inform you when a
position fix is obtained by transitioning to either the “2D” or “3D” banner.
When four or more satellites with good geometry are available, the GPS 55
will automatically operate in the 3D mode in which latitude, longitude, and
altitude are computed. If only three satellites are available, the unit will
operate in 2D mode in which only latitude and longitude are computed. When
operating in the 2D mode, the unit will use the last computed altitude or your
last entered altitude (Section 3.3 describes how you may enter the altitude).
If less than three satellites with acceptable geometry are available, the “DR”
banner will be displayed.
Your GPS 55 will automatically update satellite orbital data as it operates. If
you have not operated your unit for a period of six months or longer, it will take
approximately 12.5 minutes to search the sky and collect new orbital data.
You will be informed when your unit is searching the sky with the message