@GalileoSats

All about the Galileo satellites (not an official EU or EUSPA account!). Operated by @bert_hu_bert.

 29599.8km
galmon.eu/
Joined July 2019
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GalileoSats 🛰🇪🇺 retweeted
Daniel Estévez@ea4gpz3 Oct 2023
New blog post: Update on the Galileo GST-UTC anomaly. After one month I have updated my plots with new data. The anomaly persists. The GST-UTC offset has now gone negative. destevez.net/2023/10/update-… @GalileoSats
A plot of the system time differences in the broadcast data compared with the difference of the CODE minus broadcast clock. This can be used to study the GST-UTC offset. We see that it hasn't been close to zero since the end of August. It was positive during the first half of September, and now it has become negative.

ALT A plot of the system time differences in the broadcast data compared with the difference of the CODE minus broadcast clock. This can be used to study the GST-UTC offset. We see that it hasn't been close to zero since the end of August. It was positive during the first half of September, and now it has become negative.

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GalileoSats 🛰🇪🇺 retweeted
Shrirang Kahale@AlbonyCal14 Sep 2023
msn.com/en-in/money/topstori… iPhone 15 added support for NavIC (Navigation with Indian Constellation ) for GPS :)
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GalileoSats 🛰🇪🇺 retweeted
Josef Aschbacher
@AschbacherJosef3 Sep 2023
Warmest congratulations to @isro and all involved in the Aditya-L1 mission for this achievement, following so closely after #Chandrayaan_3. Honoured to be able to help both missions with @esaoperations support.
ISRO
@isro3 Sep 2023
Aditya-L1 Mission: The satellite is healthy and operating nominally. The first Earth-bound maneuvre (EBN#1) is performed successfully from ISTRAC, Bengaluru. The new orbit attained is 245km x 22459 km. The next maneuvre (EBN#2) is scheduled for September 5, 2023, around 03:00 Hrs. IST
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Really very nice work. It does look like Galileo may be broadcasting the *inverted* UTC drift rate! destevez.net/2023/09/galileo…
Daniel Estévez@ea4gpz2 Sep 2023
New blog post: Galileo GST-UTC anomaly. @GalileoSats and others have noticed that lately the Galileo system time has drifted unusually far away from UTC. Here I study the situation, comparing the satellite clock biases in the navigation message with CODE's precise clocks. 🧵
A plot of the difference between the broadcast clock bias and the CODE precise clock bias for each satellite, and for the average of all satellites. We see that the values are around zero during the middle of August, but at the end of August they start decreasing until reaching -18 ns.

ALT A plot of the difference between the broadcast clock bias and the CODE precise clock bias for each satellite, and for the average of all satellites. We see that the values are around zero during the middle of August, but at the end of August they start decreasing until reaching -18 ns.

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These graphs are quite suggestive. Left is what is being transmitted (check the green lines), right what it looks like if you flip the sign:
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GalileoSats 🛰🇪🇺 retweeted
Daniel Estévez@ea4gpz2 Sep 2023
New blog post: Galileo GST-UTC anomaly. @GalileoSats and others have noticed that lately the Galileo system time has drifted unusually far away from UTC. Here I study the situation, comparing the satellite clock biases in the navigation message with CODE's precise clocks. 🧵
A plot of the difference between the broadcast clock bias and the CODE precise clock bias for each satellite, and for the average of all satellites. We see that the values are around zero during the middle of August, but at the end of August they start decreasing until reaching -18 ns.

ALT A plot of the difference between the broadcast clock bias and the CODE precise clock bias for each satellite, and for the average of all satellites. We see that the values are around zero during the middle of August, but at the end of August they start decreasing until reaching -18 ns.

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GalileoSats 🛰🇪🇺 retweeted
Daniel Estévez@ea4gpz1 Sep 2023
This is definitely weird. I noticed the other day that the GST-UTC was somewhat large, but didn't look into it. Now it is much larger than I ever recall having seen it, and there is the weird thing where they broadcast a negative slope ramp but then periodically make it jump up.
A plot of the GST-UTC offset in the INAV message, obtained from the public.galmon.eu Grafana dashboard. We see that the offset is currently at 17 ns, which is really large, since usually it's only a couple ns. This has been creeping up over the last week, and moreover the plot looks like a bunch of negative slope ramps which keep jumping up.

ALT A plot of the GST-UTC offset in the INAV message, obtained from the public.galmon.eu Grafana dashboard. We see that the offset is currently at 17 ns, which is really large, since usually it's only a couple ns. This has been creeping up over the last week, and moreover the plot looks like a bunch of negative slope ramps which keep jumping up.

GalileoSats 🛰🇪🇺@GalileoSats31 Aug 2023
Something might be up with the Galileo UTC offset, as discussed on the TIME-NUTS list: febo.com/pipermail/time-nuts…
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Something might be up with the Galileo UTC offset, as discussed on the TIME-NUTS list: febo.com/pipermail/time-nuts…
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🛰#Galileo update: GSAT0216 has been upgraded with the improved I/NAV message. More info: gsc-europa.eu #EUSpace #UseGalileo
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#Galileo OSNMA: Internet Data Distribution (IDD) document just released! The information provided in this document along with the OSNMA SIS ICD and the OSNMA Receiver Guidelines allows the full implementation of the OSNMA protocol. More info: gsc-europa.eu/news/galileo-o…
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GalileoSats 🛰🇪🇺 retweeted
Dr. Robert Rohde@RARohde31 Jul 2023
Why does it potentially matter? Despite its low concentration (parts per million), water vapor remains a significant infrared absorber in the upper atmosphere (reference plot prior to the HTHH eruption). Boosting upper atmosphere water vapor will impact the greenhouse effect.
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Four years of Galmon more or less! Do you remember when you joined Twitter? I do! #MyTwitterAnniversary
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