What are the most likely causes of simultaneous slips of all satellites in my Rinex report? (I can't get them to line up here, but they really do.)?ÿ The .18o file shows for one 30-second epoch that all or nearly all the same satellites are listed but have no measurement entry.
Birds on the antenna??ÿ Big truck passing by??ÿ Cable intermittent??ÿ Receiver getting flaky??ÿ Other?
.3|Looooo-___
26|LoooooooooI+___
16|LoooooooooIooooIoo-____
23|LoooooooooIooooIoooLI___
27|LoooooooooIooooIooooooIoo--__
.9|LoooooooooIooooIooooooIoooI-_
.7| _-IoIoooooIooooIooooooIoooooo
.8| __--ooooooIooooIoooooomoooooo
30| ___,IooooIooooooIoooooo
11| ___LIooooooIoooooo
28| ___-IooooooIoIoooo
?ÿ
UFO hovering low or touching down.
Paul in PA
Were you recording to the receiver or data collector??ÿ
It would be really difficult to lose ALL satellites. So, a hardware or software glitch is likely the culprit.
You could also try importing the native static file into your choice of software to see if the lapse exists in the original file as well.
Many years ago in the early days of dual frequency receivers we would get cycle slips on all channels due to nearby radio interference, for example keying the mike on a handheld radio held near the antenna, or police radar guns, etc. This was using trimble 4000SSi, and the problem was mainly fixed in the 4000SSe (or maybe the SSe was the one with the problem and the SSi fixed the problem, I can't remember exactly). Point is that the receiver circuitry was susceptible to interference. This was also a problem in the very early days of airborne. We solved that by moving the VHF antennas from the top of the plane to the belly of the plane.?ÿ
?ÿ
This was recorded in the 4000sse memory, which had been cleared before the session.?ÿ I think the ssi is the later of the two models.
I use Trimble GPLOAD to pull the data into the computer, and usually run TEQC to translate to RINEX.?ÿ I look for error messages, but don't always study the TEQC report carefully.
This session had three totally lost epochs spaced out by more than an hour.?ÿ It was the one in the median of US Hwy 30 that I posted a picture from recently, so there would be a lot of truck traffic with CB radios, and a possibility of radar or radar jammers.?ÿ I thought about overheating, but all these events occurred before local noon.?ÿ
Another session that has such an event was along a 2-lane road busy with mostly local traffic, a few miles from an airport and nearly under the main landing approach so there could be comm and radar.?ÿ Looking back I have found more instances in older files, and will try to examine more of them to see if I can find a pattern of time, place, etc.
Clock stearing enabled or not?
Hard to see if drops have have even?ÿ spacing or not. Usually clock issues are temperature dependant too, so not always even spaced drops.
(I believe, and have heard, that OPUS likes non-steared inputs.)
Big trucks is good guess too.?ÿ
What does receiver do in open?
FWIW,
Looking at?ÿ http://www.unavco.org/software/data-processing/teqc/doc/UNAVCO_Teqc_Tutorial.pdf and the screen captures below (from the qc full option) might be of some help.
I do not know whether your summary file was run in "lite" of "full" mode. I recommend the latter which requires a NAV message matching the OBS file. Note that the example file has no clock updates. Clock steering on some receivers (all?) can be selected in the receiver setup. Note as well the dn option explanation.
Unfortunately, I cannot provide a definitive explanation for the slip common to all SVs.?ÿ
BTW, a new version of teqc was released dated 5 March 2018. The PDF linked above pre-dates this release. See:?ÿ https://postal.unavco.org/pipermail/teqc/2018/002450.html
HTH,
DMM?ÿ
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