Garmin GTN 625 Pilot's Manual page 452

As the GPS receiver locks onto satellites, a signal strength bar appears for each
Foreword
satellite in view, with the appropriate satellite number (01-32, SBAS satellites will
have higher numbers) underneath each bar. The progress of satellite acquisition
Getting
Started
is shown in the following stages:
Audio &
Graph Symbol
Xpdr Ctrl
No signal strength bars
Com/Nav
Grey signal strength bars
FPL
Direct-To
Yellow signal strength bars
Proc
Cross-hatch cyan signal
strength bars
Wpt Info
Solid cyan signal strength
bars
Map
Solid green signal strength
Traffic
bars
Terrain
Weather
The Time and other data may not be displayed until the unit has acquired
Nearest
enough satellites for a fix.
Services/
Music
The sky view display at the left of the page shows the satellites currently in view
as well as their respective positions. The outer circle of the sky view represents
Utilities
the horizon (with north at the top of the circle); the inner circle represents 45°
above the horizon and the center point shows the position directly overhead.
System
Each satellite has a 30-second data transmission that must be collected
Messages
(hollow signal strength bar) before the satellite may be used for navigation (solid
signal strength bar). Once the GPS receiver has determined your position, the
Symbols
GTN unit indicates your position, altitude, track and ground speed. The GPS
receiver status field also displays the following messages under the appropriate
Appendix
conditions:
Index
15-16
The receiver is looking for the satellites indicated.
The receiver has found the satellite(s) and is collecting
data.
The receiver has collected the necessary data but the
satellite is not being used in the position solution as it
has been excluded.
The receiver has found the satellite(s) but it has been
excluded by the FDE program as a faulty satellite.
The receiver has collected the necessary data, but is
not using the satellite in the position solution.
The receiver has collected the necessary data and the
satellite is being used in the position solution.
The "D" character inside the bars indicates differential
D corrections (e.g. WAAS) are being used for that
satellite.
Table 15-2 Signal Strength Bar Graph Description
Garmin GTN 625/635/650 Pilot's Guide
Description
190-01004-03 Rev. K