38
iGage
iG8 User Manual
corrections from an unintended network source
someone else’s UHF base. You can debug this by
looking at the ‘Ref’ tab:
Is the ‘Distance to Ref’ correct for your base? In this
example, the base in use is nearly 100 miles away,
the Rover will never fix!
3.
If your Rover is under moderate or heavy canopy, it
may take a while for it to FIX ambiguities. Watch the
‘Hsdv’ and ‘Vsdv’ (Horizontal and Vertical estimated
errors):
If they are dropping, then the receiver may FIX after
some time and it is worth waiting. If Hsdv / Vsdv
continuously reset from low to high, there may be
too much canopy for the GNSS engine to fix.
You might be able to move to the open, get a FIX,
then carefully move back to the obstructed location
and make an accurate measurement.
Changing the elevation mask on the ‘Receiver’ tab
may help. Dumping the receiver (turning upside
down then right side up) may help.
Raising the rod height may help.
Waiting a while for a better satellite constellation
may help. (See the Mission Planning section below.)
4.
If the Rover is FLOATing, but never fixes, there could
be high multipath or canopy at the base. Remember
that ANY canopy obstructions at the base affect
EVERY rover location and every measurement.
5.
Is the Latency less than 4 seconds? If the Latency
builds up to values larger than 4 seconds there may
be someone else on the same UHF radio frequency
or the UHF radio signal is not strong enough to reach
the rover dependably. Use a handheld radio to
monitor the frequency.
If you are using a network connection, then the cell
connection may be unstable.
6.
Have you checked Mission Planning? See section
‘
Check the ‘SATView’ under ‘Monitor/Skyplot’. A
satellite distribution like this:
is good and the receiver should FIX within 30
seconds if in open sky.
However a sky-plot like this:
where all of the satellites are in one quadrant, or the
satellite count is very low, just won’t be sufficient to
get a FIXED solution.
Status = ‘AUTONOMOUS’, ‘WAAS’ or ‘DGPS’:
The Monitor/Skyplot display on the data collector will
show ‘AUTONOMOUS’, ‘WAAS’ or ‘DGPS’:
