[teqc] poor tracking of L1 with NetRS and constant value of MP1 (0, 15)

Lou Estey lou at unavco.org
Fri Jan 16 12:05:26 MST 2009


Dear Giorgi,

> Perhaps you have encountered something similar in the past:
> 
> We have installed a Trimble NetRS receiver as a permanent station at 
> Cabo Busto (Asturuas, Spain). One Hjek the station was working fine, but 
> afterwards it started to have problems tracking the L1 signal.

> SV+|--------|--------|--------|--------|--------|--------|--------|--------+SV
>  22|Lcccccccccccc           LLccccLooooooccc.                              | 22
>  12|LccIooooooooooooocccLL                                                .| 12

The 'c' (on these lines and for the other GPS SVs) indicates a problem with tracking
L2, not L1; 'c' means 'no A/S; L1 C/A', i.e. the rx _is_ tracking L1 (and only
L1) for both phase and code pseudorange during those times.  It looks like the
L2 tracking is a problem mostly at lower elevations.

Have you tried an antenna swap?

--lou

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Louis H. Estey, Ph.D.              office:  [+001] 303-381-7456
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