[IGSSTATION-7892] Re: Tracking of G04 with Septentrio receiver

Wed Feb 19 22:34:28 PST 2020

Dear all,

Incidentally, we completed a small study on L1C tracking at 300+ MGEX sites last week. Thus, we also confirm that Septentrio v5.3.0 might have L1-band tracking issues with respect to SVN74.

Below, it is a multipath average visual for all Septentrio sites reporting L1C observations by Feb 14:
http://bit.ly/3bTry48

Update to firmware v5.3.2 seems to fix the issue and brings the multipath to similar levels as for Javad & Trimble models capable of tracking L1C. 
http://bit.ly/39MusWD

The significant reduction was found for the multipath of the other signals.

For the sites mentioned earlier and few other equipped with Septentrio, the rinex files found in the IGS MGEX repository do not include L1C observations for G04. Thus, the sites appear unaffected in the processing as stated by Jan and other colleagues.

Kind regards,
Octavian

---
Dr. Octavian Andrei
Vanhempi tutkija    | Senior Researcher
Maanmittauslaitos | National Land Survey of Finland
Paikkatietokeskus   | Finnish Geospatial Research Institute
Geodesia ja geodynamiikka | Geodesy and Geodynamics

Geodeetinrinne 2, 02430 Masala, Finland

E: octavian.andrei at nls.fi
Mobile: +358469211423
Twitter: @coandrei
SkypeForBusiness: octavian.andrei at maanmittauslaitos.fi

________________________________________
From: IGSSTATION <igsstation-bounces at lists.igs.org> on behalf of Jan Dousa <jan.dousa at pecny.cz>
Sent: Wednesday, February 19, 2020 12:36 PM
To: igsstation at lists.igs.org
Subject: [IGSSTATION-7888] Re: Tracking of G04 with Septentrio receiver

Hi Nacho and Rolf,

we noticed the problem was originally triggered on 22.10.2019,
truely reffering the G04 satellite - unhealthy at that time.
SEPT POLARX5* 5.3.0 were in use at that time, and # of cycle slips
(we observed at all signals) increased significantly for GPS/G04!

It is clearly visible for several stations in the summary plot
based on G-Nut/Anubis QC monitoring of a subset of IGS stations:

https://www.pecny.cz/grc/qc/?spec=net&period=2019-Q4&sites_filter=METGS&sites=&qcparam=obspha_cyc_slps&gnss_filter_net%5B%5D=GPS&view_cnt=1&view_rng=auto&view_rng_min=&view_rng_max=&view_rng_stp=

Interestingly, three stations from the subset also didn't show
the problem though equipped with the same receiver, even though
tracking the L1C (attached list of affected/unaffected stations).

Best regards,
Jan

Dne 2020-02-19 09:19, Nacho Romero napsal:
> Dear Rolf & Emilio,
>
> Your recent message about Septentrio receiver indicates issues with
> the L1C tracking and some users have concluded that the L1C
> observables could be less precise than needed, on the other hand I
> think you mean that just tracking the new L1C signal of G04 with the
> affected receivers is affecting all other G04 observables.
>
> Could you please confirm whether your concern is only about the L1C
> signal observables and what observables you used to check the MW
> linear combination ?
>
> Am I correct in concluding that the upgrade of the PolaRx5 receivers
> to 5.3.2 is recommended even if the observables of the L1C are not
> processed? ... because something (unknown?) is happening to the other
> L1 observables?
>
> Thanks again
>
> Best regards,
> Nacho
> _______________________________________________________________
>
> Ignacio (Nacho) Romero
> Aerospace Engineer, PhD
> CSC Ltd @ ESA/ESOC/OPS-GN
> Satellite Navigation Engineer @ ESOC Navigation Support Office
> IGS Infrastructure Committee Chair
> www.navigation-office.esa.int [2]
> www.canaryspaceconsulting.co.uk [3]
> _______________________________________________________________
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> On 18/02/2020 06:02, CODE AC team wrote:
>
>> Dear colleagues,
>>
>> the new GPS Block IIIA is active as PRN G04 since a few months. We
>> have been concerned in our IGS processing because of a significantly
>> higher amount of observations that are indicated as "bad" for this
>> particular satellite.
>>
>> When digging down our colleague Emilio discovered that the
>> Melbourne-Wuebbena linear combination for this particular satellite
>> is more noisy than for other satellites for some stations (30 out of
>> 230). All these sites are equipped with a Septentrio receiver
>> (POLARX5*, firmware 5.3.x; see attached file).
>>
>> Interestingly, there is also a number of sites with the same
>> receiver/firmware (MAR6, SPT0, ONSA, QAQ1, SCOR, VIS0, KIR0, ABMF)
>> where the noise of the MW linear combination is in the usual range.
>>
>> Some discussions with Martin Lidberg (responsible for most of the
>> "working" receivers) and colleagues from Septentrio have shown:
>> - tracking the new L1C signal with a Septentrio receiver is causing
>> these problems with the firmware versions 5.3.0 and 5.3.1
>> - the installation of the firmware version 5.3.2 should solve this
>> issue.
>>
>> Thank you for your consideration.
>>
>> Best regards
>>
>> Rolf & Emilio
>> on behalf of the CODE AC
>>
>> PS: The analysis is done based on our database of 30-sec. RINEX2
>> and RINEX3 files as used for IGS and EPN processing.
>>
>> _______________________________________________
>> IGSSTATION mailing list
>> IGSSTATION at lists.igs.org
>> https://lists.igs.org/mailman/listinfo/igsstation [1]
>
>
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> [2] http://www.navigation-office.esa.int
> [3] http://www.canaryspaceconsulting.co.uk
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