Wintec G-RAYS 2 WBT-201, User Manual

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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 G-RAYS 2 can receive reflected
weak GPS 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 (especially when manipulated 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 G-RAYS 2, 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 30~100 min,
G-RAYS 2 will stop to work to prevent total exhaust of power.