[time-nuts] Trimble UCCM survey results

Tom Curlee tcurlee at sbcglobal.net
Tue Dec 20 01:28:13 EST 2016

A couple of questions:
I've just started using  LH 5.0 with my 2  GPSDO units (Thanks Mark!) - a Trimble UCCM and a Z3801A.  Oddly, I'm very getting different survey altitude values.  The Z3801A is around 81 M, which agrees within 1 or 2 meters with Google maps (not a perfect source, but close), but the UCCM is usually around 48M to 53M depending on which survey I want to believe.  Both receivers are locked and both are fed off the same antenna through a splitter.  I admit that the antenna placement is very poor - anything below 60 degrees elevation to the north is blocked (LH is great for antenna placement analysis).  Anyone have any ideas?
A question on LH usage.  When the UCCM is in the position hold mode, what happens when a precision survey is run?  Looking at the .lla file shows that every position, including the final processed location,  is the same as that shown as the position hold location on the main LH screen.  Do you need to take the receiver out of the hold mode to run a precision survey?  How?  How is the position scatter plot used with a survey?  I usually don't see any positions plotted, certainly not when running a precision survey.  I think I saw data plotted when I did an internal survey.
Many thanks for any info.  And thanks again to Mark and John for all the work.

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