Figure 4.38: Satellite status
Figure 4.38 illustrates the
GPS
satellite reception page. In this example the GPS SD+ shows that 8
satellites are visible, and all 8 are being used to provide the position x. Each bar shows the signal
strength for each individual satellite. A lled bar indicates the GPS SD+ has a
lock
on that satellite.
The
position dilution of precision
(pdop) shown gives an indication of how reliable the
GPS
data is at
the moment. The lower the pdop value the more accurate the position x. Values bellow 2.5 are fairly
accurate. If the GPS SD+ is switched on in a location where no satellites are visible (indoors for example)
it will go into wide search mode. If this occurs, going outdoors again will make the GPS SD+ take an
increased amount of time to pick up satellite signals. If this occurs pushing ENTER on the
GPS
menu
item will reveal the
Reset GPS
option, changing it to yes will make the GPS SD+ reset the
GPS
status
and start a new search (see Figure 4.39). So if you notice GPS SD+ is taking abnormally long to get a
x (over 2 minutes) a
gps reset
will probably get it locked quicker.
Figure 4.39: GPS Reset
44