E-TRAK/R 5000, Руководство пользователя

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When the Bearing History arc is very wide it means you are
receiving RDF reports from all around you. This happens
when you are rapidly changing the direction of the tracking
car (U-turn or navigating a parking lot) or are receiving
multipath and reflections from many directions (Figure 1).
With GPS turned on various messages appear in the Text
Message Box (see page 21). These include information
about GPS communication and more importantly Distance
to Target estimations based on GPS data received from the
beacon and relative GPS location of the tracking vehicle.
“Distance to target 0.5 miles”. As you get closer the number
will get smaller and the audible pitch of beacon signal will
get higher.
The ideal tracking distance is around 0.1 to 0.2 miles. This
keeps the tracking vehicle out of the target vehicles sight
while maintaining relatively reliable two-way communications
between the E-TRAK/R and the E-beacon. This distance may
be significantly less in urban environments and areas of high
RF ambient noise.
It is common to have the RDF indicator appear to be in
direct contradiction to the GPS coordinate arrow due to
reflected signals. The target may have just turned right and
your GPS update will track its location but RDF signals
may be bouncing off a building from the left (Figure 2).
Recognizing that the target vehicle couldn’t have turned left
you follow to the right.
Figure 2
Figure 1
CH
Mute Dim Tracker
2 171.600 MHz
Fil.
CH
Mute Dim Tracker
2 171.600 MHz Raw
CH
Mute Dim Tracker
2 171.600 MHz
Got valid GPS data
Raw
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TARGET
BEACON
ACTUAL GPS
COORDINATE
REFLECTION
OFF BUILDING
TRACKER