[teqc] inexplicable value on Galileo Navigation Message

Lou Estey lou at unavco.org
Fri Feb 1 07:21:38 MST 2019


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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