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ECIN | We have encountered a situation on our Trimble RTK systems that our dealer is investigating with Trimble support to get resolved before planting, and I thought I would post here to see if anyone has experienced the same.
Here is the equipment:
Trimble 542 RTK fixed base with 450mhz radio running SecureRTK (part of dealer RTK network)
Trimble 432GNSS, 442, and FmX (GNSS unlocked) receivers with 450 mhz radios all running SecureRTK
Here is the situation:
Receivers have worked great since our dealer moved to 450 mhz RTK in 2010
Still were working fine through 2012 summer tiling (July/August)
SecureRTK was set up on everything (Early September)
Harvest started, and we pay little attention to receiver/sv stats as long as they are working!
Tiling resumed (December-February)
In December, I started noticing lower satellite numbers (never higher than 10) on the receivers in our tiling setup (FmX and 432GNSS), while the base would still show 13 to as many as 18. We were running <1 mile from the base in an open field with no tree borders. In the same field in August, with the same rovers, we would regularly run 12 -13 sats.
This all became a concern when I started re-mapping our field boundaries in February, and with the majority of our fields having at least one woods on a property line, GPS quality was inconsistent and difficult to maintain. Typically around woods in our area in the past, with GNSS, sats will drop to 7 or 8, and RTK still works great. Now, around woods, they will often be 4 to 7, and RTK loses fix frequently. FWIW, while running the boundaries, I was also using a PDL450 repeater at the field, so corrections were not an issue.
Yesterday, I took the FmX and 432 out in the driveway near the base, and wrote down all of the sats that each was seeing. The FmX and 432 showed the same 8 GPS sats (2,5,9,15,18,21,26,29) and the same 4 GNSS sats (4,5,19,20), in the background, but only displayed 8 on the summary screens. At the same time, the base showed the same 8 GPS sats, the same 4 GNSS sats (plus 1) in the background, and displayed 13 on the home screen.
It appears as though the rovers are seeing the GNSS sats, but are not including them in the mix.
I apologize for the rambling details; please let me know if I missed anything!
Edited by beiswanger 3/12/2013 11:03
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Trimble receivers and GNSS oddities
