Page | 23 Revision 1.4 15 January
2015
Troubleshooting guide
Restart
→
Should you need to restart the LabSat 3 unit for any reason please hold down the power button
continuously for at least 30 seconds. Release the button and then press again briefly to switch
device on.
Trouble Locking onto Satellites
If the GNSS engine under test is having trouble locking onto satellites when replaying recorded data then
please follow the checklist below for typical solutions:
→
During recording of LabSat data, ensure that the antenna is placed in a position where it has an
unobstructed view of the sky. (See ‘GNSS Antenna Placement’ below)
→
Check the antenna connection with the LabSat; any small amounts of dirt in the socket can cause a
significant reduction in signal strength. Also check the cable for any damage.
→
If possible try another known working antenna, to confirm antenna functionality.
→
Perform a Cold Start of the device under test after each start of the data replay. This is because a
GNSS receiver will normally download and store almanac information to help it re-acquire satellite
signals from power up. Therefore, when a recorded GNSS test signal is replayed, it is possible that
any almanac data previously stored in the GNSS engine will cause it to look for the wrong satellite
signals.
Please also note that when using any GNSS equipment, a clear
view of the sky, without physical obscuration, is important.
Objects in the surrounding area such as tall buildings or trees
can block the GNSS signal causing a reduction in the number of
satellites being tracked, or introducing reflected signals that
can decrease the accuracy of the system. Note that clouds and
other atmospheric conditions do not affect the LabSat 3
performance.
GNSS antennae require a ground plane to operate correctly. This helps to reduce unwanted reflections
of the GNSS signals caused by nearby objects, and usually the metal roof of a vehicle performs this
function. However, if a test requires an antenna to be placed either off the vehicle, or on a vehicle that
does not have a metallic roof, a special
ground plane
antenna must be used. This has an internal
ground plane and can operate perfectly without the need for mounting on a metal surface. Ground
plane antennas are available from your LabSat distributor
Optimising Data Transfer Speeds
→
LabSat 3 uses a high speed SD card to record and replay RF data. If you wish to transfer LabSat
scenarios from and to the LabSat 3 Hard Disk Drive (HDD) it is recommend to use a PC that supports
USB3.0. The LabSat 3 HDD supports USB3.0 connection and to get maximum transfer speed then
the SD card reader should also have USB3.0 capability.