Scott Tilley 🇺🇦 Profile picture
Бо плач не дав свободи ще нікому.
Mar 19 7 tweets 3 min read
MERIDIAN 9 on it's Eurasian apogee.

As you can see here there's legit Russian military traffic here.

Aircraft spotters I make a call for you to pay attention to this 🧵. MERIDIAN 9, 990MHz transponder narrow data. This type of traffic has been observed for decades on the Molniya-T1 spacecraft too. It is thought to be part of the Russian Strategic Rocket Force's communication system.
Mar 18 4 tweets 2 min read
MERIDIAN 8 RADAR re-emissions seen this morning.

Using the AM demodulator to examine the pulse dynamics of each RADAR. Here's another recording revealing a 4th radar with a much different higher pitched pulse pattern. It comes and goes so listen to the entire track.
Mar 17 4 tweets 1 min read
My wife says this blown to bits Russian EW warfare equipment looks like our backyard. Not sure why they need 2.4GHz grid but we've seen other off the self comms equipment blown up too. If you look carefully at the second image there are two feeds, so they had two complete WiFi antennas. Most likely for some local link they planned to establish. I wonder if they use secure or open WiFi networks?
Mar 12 4 tweets 2 min read
Russian military MERIDIAN 7 C-band this evening. There's now a 100KHz non-regenerative transponder on the band. I've seen these appear rarely on X-band but until now not on C-band. MERIDIAN 7 with the usual TTY beacon on 3610MHz.
Mar 6 8 tweets 3 min read
Here's how to understand the RADAR data I'm sharing.

The Russian MERIDIAN satellites are in High Earth Orbit and have their apogees fixed above the Northern hemisphere over Russia and North America. This allows the spacecraft to see both places at once.

THREAD
1. Being in a highly elliptical orbit the MERIDIAN satellite is actually visible to observers on the opposite side of the world at a very low elevation in their sky. Here's an example plot of simulation of MERIDIAN 8 at the North American apogee visible from Ukraine.
2.
Mar 5 15 tweets 6 min read
Some details on what is known about the MERIDIAN 990MHz transponder system. This transponder seems to be a legacy of the older Soviet MOLNIYA system as evidenced by this excerpt from a report to the US congress in the 1980s.
THREAD
When the last of the MOLNIYA's were still operational amateurs noted transponder activity from them while the spacecraft were on the Russian/European apogee. But by 2011 MOLNIYA went silent and was replaced by MERIDIAN and during the gap no one looked...
Mar 4 4 tweets 2 min read
It's March 4th.

Today a piece of humanity's cast off technology will impact the Moon in a event that would have gone unnoticed had it not been for the work of a few folks looking up in unpaid and normally unnoticed toil... (1/4) In order to explore the Moon and for all of humanity to share in the potential positive aspects of that exploration and utilization we need to be able to monitor activity around the Moon in a more transparent and accessible way.

(2/4)
Feb 27 5 tweets 3 min read
Based on research here's the layout of Russian military satellite communications at this time from Ukraine. 1st image is a sky view as you would see it from ground looking at the GEO satellites, 2nd a chart view of all assets visible and 3rd a map view. (1/n) ImageImageImage Understanding where command and control assets would need to view these satellites limits their tactical options to hide and helps one hunt them. (2/n)
Feb 27 4 tweets 1 min read
A primer on the Russian military's MERIDIAN satellite constellation.

MERIDIAN is an High Earth Orbit (HEO) Russian military satellite designed to provide communications to northern latitudes (I.e. Russia et. al.). It is a modern version of the MOLNIYA constellation. Image The MERIDIAN constellation is primarily designed to offer communications to high northern latitudes where access to GEO satellites could be difficult or impossible.
Feb 26 4 tweets 1 min read
This could be very well be a beacon of hope, the sound of resistance that can be heard around the world.

Russian military satellite MERIDIAN 8 reveals radar emissions that most are coming from Ukrainian forces defending themselves. After days of onslaught Ukraine stands.
Feb 26 6 tweets 2 min read
This is the P-441 communication complex that the Russian military uses for MERIDIAN, RADUGA and maybe transponders on other assets. It uses C and X-band. On these bands a clear view of the satellite is needed. Many variants of this system exist. (1/n) Tactically, you'd likely want to hid this thing as it's a critical asset and part of your command and control which limits your options to deploy it. MERIDIAN could give you the ability to hid it and use those satellites high elevation to advantage. From the operating manual...
Feb 26 4 tweets 2 min read
No signals from MERIDIAN 4 today. I suspect it has gone offline. We should be hearing about a replenishment soon.

This creates a gap in MERIDIAN Molniya coverage for ~8 hours each day. Much like when M3 went belly up.
Unlike when MERIDIAN 3 went down they still had MERIDIAN 2 stranded in the wrong orbit but still operational and filling in some of the gap from time to time.
Feb 24 4 tweets 1 min read
The world can observe Russian military activity on UHF, C and X-band via their communication satellites in GEO and HEO. Observers should scan 279 +/- 2MHz, 484MHz +/- 2MHz , 980-1000MHz, 3.4-3.7GHz and 7.5GHz +/- 100 MHz for activity from GEO and HEO assets. Reports to follow. Search my profile @coastal8049 and use keywords like MERIDIAN to find details.
Jan 13 8 tweets 5 min read
The last observation before #Change5 'disappeared' after Dec 2nd, was 19 degrees from the Moon on the western side. Perhaps just before a burn!? This as you will see is significant to understand CE5's present trajectory and why I'm pretty much convinced it is in a DRO now. (1/n) The geometry of Dec 2nd timing is curious to say the least. If you examine this plot you'll not there are a number of possible DROs. If you measure the elongation angles for the second closest to the Moon you get ~19 degrees. (2/n)
Jan 12 8 tweets 5 min read
What in tarnation is a Distant Retrograde Orbit (DRO)?

For those wondering what I'm waving my hands about these days about here's a THREAD about what a DRO is and why it may be something you hear a lot more of soon... (1/n) Image A DRO is a long term STABLE orbit for a very small mass object around the smaller of two much larger bodies that are in a two-body orbital system. As the Earth has a Moon, one could place a spacecraft in a DRO of the Moon. (2/n) web.archive.org/web/2015011122… Image
Jan 9 4 tweets 2 min read
#Change5 DRO state vector estimate with rationale.

Amateurs lost signal ~2021-12-03. About 3 integer periods of ~13 days, which is around the optimal DRO period. We appear to be seeing spacecraft at eastern elongation now. So... (1/n) From what I understand of DRO insertion geometry one likes to enter DRO from one of the elongation points not the EM-L1 or EM-L2 points. This insertion burn occurred ~ 2021-12-03. SOURCE: ntrs.nasa.gov/api/citations/…
Jan 9 4 tweets 4 min read
Could #Change5 be in a Distant Retrograde Orbit (DRO) of the Moon pulling off a space first?

CE5 is ~15deg east of the Moon suggesting it is ~100000km distant from the Moon. I made a model DRO in GMAT seeded it with a start from EM-L2 around 2021-12-01 00:00 UTC, Hmmm... (1/n) Examining papers on the upcoming #NASA SLS EM-1 mission that will use a DRO reveals the geometry somewhat fits the limited observations we have of #Change5 since it was recovered a couple of days ago. (2/n) SOURCE: ntrs.nasa.gov/api/citations/…
Oct 9, 2021 7 tweets 5 min read
March 2021 - 18SPCS reported that YUNHAI 1-02 [44547, 2019-063A] had broken up. Since the breakup report, amateurs have monitored radio emissions on 1704MHz. As the spacecraft straddles the terminator it was lost in the glare of daylight until now...
THREAD @18SPCS reported that YUNHAI 1-02 broke up and amateurs noticed it continued to emit. The following thread should catch you up on some of these facts.
Jan 16, 2021 7 tweets 3 min read
Well well well, the mystery of what the signal on ~992.4MHz/~1000.44MHz and FM audio on ~998.94MHz from the Meridian satellites is resolved. It's SECAM TV channels from Turkmenistan. SECAM channel spacing is 8MHz and video carrier to audio carrier is 6.5MHz which matches. I mused a few weeks about about the curious nature of the 15.625MHz sub-carriers around the primary.
Dec 15, 2020 8 tweets 7 min read
Steffan Watkins provided a wealth of AIS data from MarineTraffic about the journey of Yuan Wang 3 to the #Change5 re-entry skip point in the Arabian Sea. The data reveals that the ship did some interesting stop and goes prior to arriving on station to look at what? THREAD. 2020-12-10 UTC between 18:30 & 22:30, Mars was at the zenith when they stopped and set just before they got underway again. Perhaps providing support for TIANWEN-1 on the way to Mars?
Dec 15, 2020 14 tweets 7 min read
Here's a plot of an estimated ground track for the #Change5 re-entry.
This THREAD will discuss:
- Evidence supporting this ground track,
- Alternatives that have been excluded,
- 'Skip' re-entry profile visibility characteristics,
- State vector confirmation of timings/position. Two possible re-entry ground tracks have been explored. The one presented is favoured because the tracking ship Yuan Wang 3 is now presently at the 'skip re-entry perigee'. Using AIS data dug up by @steffanwatkins the ship has been loitering in the area for a day or so now.