[teqc] inexplicable value on Galileo Navigation Message

Lou Estey lou at unavco.org
Fri Feb 1 10:42:10 MST 2019


dear Bernard,

Exactly!  My 1st point has been that the Trimble record in question does not make
whether setting bit 8 or 9 is the correct thing to do when the source was I/NAV E1-B,
because it doesn't really indicate what the "source" for the SV clock model parameters,
ToC, and SISA was.  And my 2nd point has been that the RINEX spec does not really say
that one of bit 8 or bit 9 actually needs to be set, or address what to do in this situation.

At this point for the next release, right or wrong: bit 9 is going to be set if the
Trimble decoded Galileo nav record indicates the source to be I/NAV E1-B.

--lou

On 01-Feb-19 10:29 AM, Bonhoure Bernard wrote:
> Dear Lou,
> 
> Actually, bits 8 and 9 indicate for what iono-free combination are the clock parameters. This is clearer in Galileo SIS ICD.
> 
> --Bernard
> 
> -----Message d'origine-----
> De : Lou Estey <lou at unavco.org>
> Envoyé : vendredi 1 février 2019 18:13
> À : Bonhoure Bernard <Bernard.Bonhoure at cnes.fr>
> Cc : teqc support discussion list <teqc at postal.unavco.org>; Mathieu Peyréga <mathieu.peyrega at gmail.com>
> Objet : Re: [teqc] inexplicable value on Galileo Navigation Message
> 
> Great, Bernard, thank you for the information.  Then that's what the next teqc release will have.
> 
> But, personally, I think the RINEX specification is about as clear as mud on this particular point.
> 
> cheers,
> --lou
> 
> On 01-Feb-19 10:08 AM, Bonhoure Bernard wrote:
>> Dear Lou,
>>
>> Yes.
>>
>> --Bernard
>>
>> -----Message d'origine-----
>> De : Lou Estey <lou at unavco.org>
>> Envoyé : vendredi 1 février 2019 18:07 À : Bonhoure Bernard
>> <Bernard.Bonhoure at cnes.fr> Cc : teqc support discussion list
>> <teqc at postal.unavco.org>; Mathieu Peyréga <mathieu.peyrega at gmail.com>
>> Objet : Re: [teqc] inexplicable value on Galileo Navigation Message
>>
>> dear Bernard,
>>
>> Therefore you are saying to set bit 9 if the source is I/NAV E1-B, correct?
>>
>> --lou
>>
>> On 01-Feb-19 09:58 AM, Bonhoure Bernard wrote:
>>> Dear Lou,
>>>
>>> Considering the RINEX 2.12 which supports  the Galileo navigation message for RINEX2, it seems that this is similar to the RINEX3 for the source description.
>>>
>>> So we expect the following decimal values wrt signal frequencies for the Galileo Data source in RINEX2.12:
>>> - Decimal 258 = binary 0100000010 for FNAV transmitted in E5aI signal
>>> (reserved or non defined bits are set to 0)
>>> - Decimal 513 = binary 1000000001 for INAV transmitted in E1B signal
>>> - Decimal 516 = binary 1000000100 for INAV transmitted in E5BI signal
>>> - Decimal 517 = binary 1000000101 for INAV merged from E1B and E5BI
>>> signals, since INAV ephemeris parameters are transmitted in these
>>> both frequencies
>>>
>>> For example in RINEX3 source for Trimble receivers are 258 for E5aI, 513 for E1B, and 516 for E5bI.
>>> I guess that the source value of '1' in RINEX 2.12 for Trimble Alloy receivers using Teqc are rather for INAV sources E1B or E5bI, since we already see 258 values (for FNAV). I don't know the Trimble format (this is a proprietary format), but I imagine the '1' source should be rather 513 (E1B source), 516 (E5bI source) or 517 (merged E1B or E5bI sources, or unknown frequency source but with INAV inside).
>>>
>>> Best Regards,
>>>
>>> Bernard
>>>
>>> Bernard BONHOURE
>>> GNSS/Galileo Navigation Senior Expert
>>>      
>>> CNES – French Space Agency
>>> DSO/NT/SN
>>>     +33 (0)5 61 28 14 62
>>>     bernard.bonhoure at cnes.fr
>>>
>>> -----Message d'origine-----
>>> De : teqc <teqc-bounces at postal.unavco.org> De la part de Lou Estey
>>> Envoyé : vendredi 1 février 2019 15:22 À : Mathieu Peyréga
>>> <mathieu.peyrega at gmail.com> Cc : teqc support discussion list
>>> <teqc at postal.unavco.org> Objet : Re: [teqc] inexplicable value on
>>> Galileo Navigation Message
>>>
>>> dear Mathieu,
>>>
>>> You've never seen what kind of message?  A Galileo I/NAV from E1-B?
>>>
>>> --lou
>>>
>>> On 01-Feb-19 07:15 AM, Mathieu Peyréga wrote:
>>>> Hello,
>>>>
>>>> my GNSS station
>>>> (http://rgp.ign.fr/STATIONS/logsheet.php?nom=magc_20181016.log) is
>>>> based on a trimble board (bd970, and the rt27 to rinex streaming is
>>>> done with teqc). It's tracking Galileo for a while now, but I've
>>>> never seen this kind of message. Station is in metropolitan France
>>>> and so probably not seing any IRNSS signals (and anyway, option is
>>>> not activated on the firmware)
>>>>
>>>> I'm keeping all .rt27 files in case and can provide them if needed for specific times.
>>>>
>>>> Best regards,
>>>>
>>>> Mathieu Peyréga
>>>> --
>>>> tel : +33 (0)6 87 30 83 59
>>>>
>>>>
>>>> Le 01/02/2019 à 14:56, Lou Estey a écrit :
>>>>> No one has commented on this in the last two days, either to this list or to me personally.
>>>>> If you have any thoughts or comments about it, I suggest you try to
>>>>> send me something very soon, or this particular bit of grizzle in
>>>>> the sausage (*) will remain as part of RINEX creation in the next teqc release and may be around for a while after that.
>>>>>
>>>>> cheers,
>>>>> --lou
>>>>>
>>>>> * see https://postal.unavco.org//pipermail/teqc/2018/002589.html
>>>>>
>>>>> On 30-Jan-19 07:34 AM, Lou Estey wrote:
>>>>>> dear Grégory,
>>>>>>
>>>>>>> Yes we track IRNSS SV also
>>>>>>
>>>>>> Then teqc's message of:
>>>>>> .dat 27/0x57-6: unknown SV type= 9 might be referring to the IRNSS
>>>>>> constellation.  The last documentation I received from Trimble on
>>>>>> .dat/.tgd record 27 (or streaming 0x57-6) does not have a type = 9
>>>>>> defined, so this is something new that Trimble has added (for at least the Alloy).
>>>>>>
>>>>>> I have an email in to our contact at Trimble to get some
>>>>>> clarification on this (and two other questions).
>>>>>>
>>>>>>> You saying "it's due to limited information", does it mean that the problem coming from receiver ?
>>>>>>
>>>>>> No, the receiver is almost certainly fine.
>>>>>>
>>>>>> This is one of those cases where the RINEX specification is asking
>>>>>> for something that's not available in the input "data" (the
>>>>>> decoded Galileo navigation message in the Trimble .tgd format,
>>>>>> record 28) or not clearly evident (at least to me) from the documentation on that "data" (the Trimble documentation on record 28).
>>>>>>
>>>>>> Where you're seeing a value of 1 for the "data sources", it's very
>>>>>> clear from Trimble's documentation that the source of that
>>>>>> particular Galileo navigation message is E1-B.  That much is 100%
>>>>>> certain.  But, from what I understand, that's all that can be known about this situation from the documentation.
>>>>>>
>>>>>> Then for RINEX, bit 8 or 9 of the "data sources" value could also be set, i.e.
>>>>>> from the RINEX spec:
>>>>>>
>>>>>> bit 8 set: af0-af2, ToC, SISA are for E5a,E1 bit 9 set: af0-af2,
>>>>>> ToC, SISA are for E5b,E1 bits 8-9; exclusive (only one bit can be
>>>>>> set)
>>>>>>
>>>>>> So in this case does one set bit 8 or bit 9?  I have no idea. Both
>>>>>> bits cannot be set (that much is 100% clear from the RINEX spec),
>>>>>> so I didn't set either one.  And, technically, not setting either
>>>>>> bit 8 or bit 9 is totally valid given the current RINEX spec for the Galileo data sources.
>>>>>>
>>>>>> --lou


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