II Morrow Inc. 920 GPS - Manual (Page 77)

The screen also shows that the signal from satellite 6 is the
weakest received. The satellite is currently located at an
elevation of 41° from a horizon azimuth of 341° and is
being tracked by the receiver.
Use the LEFT or RIGHT ARROW keys to check
signal strengths from other received satellites.
Important: When signals from fewer than
four satellites are being received, a 3D position
fix is not possible. GPS altitude cannot be
accurately calculated by the receiver.
Managing
Messages The Apollo handheld GPS receiver helps you
navigate by informing you of important events.
These events are announced by alert messages
which show on the display anytime the receiver is
operating. An audible beep sounds and continues
until you press the ENTER key to acknowledge
the alert message.
Alert messages may alert you of:
n
airspace penetration
n
arrival at the destination
n
excessive course deviation
n
low battery power
n parallel track navigation
n loss of position fix
n
expiration of countdown timer
D
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