Wintec WBT-200, Руководство пользователя

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Part 8
Trouble shooting
The GPS signal will become weak under the following conditions.
If the vehicle enters the tunnel. The GPS signal transmits linearly
down to earth and its signal is blocked out in this situation.
GPS satellite coverage gets poor because of high-rise building or
thick forest. Even though WBT-200 can receive reflected weak
GSP signal, the data might be less accurate.
The sun shade in the vehicle can partially block out GPS signal
and effect good reception. The GPS satellite is under control of
USA and the accuracy might vary depending on some special
purpose (as may be required by USA).
It is a normal situation when GPS data displayed by the receiver
device shows a big difference from real position because of
unstable atmospheric condition which causes GPS axis to drift
from actual map axis occasionally.
Some navigation software can only decode latitude/longitude from
NMEA0183 provided by logger. No altitude information is available
and therefore it cannot define vehicle’s position whether that is
over or under the bridge.
After successful positioning of WBT-200, if it is moved to another
area of 500 km away it cannot be easily re-positioned. This is
because the firstly recorded data (position, time and number of
satellites acquisitioned) is different from the new area. It will need
longer time for re-positioning.
When the power LED flashes red, the battery is critically low and
needs re-charging. If it is not recharged within 30 min, GPS will
stop to work to prevent total exhaust of power.
PIN code will be requested after Bluetooth connection initiates
between GPS and PDA. Enter code as 0000 .
Avoid placing 2 GPS devices too close during positioning.