Page 64
I Have a Question
Some helpful things to know about the
GPS Sta
tu
s
screen:
There are a total of 27 GPS satellites in orbit, arranged
so that at least 4 satellites can be seen from every point
on the planet at all times. These satellites broadcast radio
VLJQDOVWKDWDOORZ*36GHYLFHVWR¿QGWKHP$WPRVSKHULF
conditions and radiation can affect the signal strength on
the satellite’s end just as the local environment can affect
the signal strength on the recevier’s end.
Satellites
in view
are above the horizon and have the
potential to be tracked. When the device receives a valid,
continuing signal from a satellite, it marks that satellite as
tracked
. When the device synchronizes with the satellite
and locks onto its position in the sky, it marks that
satellite as
active
.
The device must lock onto at least three satellites to
estimate your latitude and longitude. If it locks onto four
satellites, it can also calculate your altitude. Generally,
the device must lock onto four satellite signals to
calculate your position accurately.
The
GPS Sta
tu
s
screen also shows the accuracy of
your position. An accuracy of 10 feet means that the
calculated position is within a 10 foot radius of your actual
position.
Once the device locks onto the satellites, it can usually
maintain the lock even if the signal strength goes down.
Also, if the device locked onto the satellite signals within
the past 30 minutes or so, it can often get a new lock very
quickly.
Ź
Ź
Ź
Ź
Ź
