Starlink 'beta' passive gimbal experiment?

[Midnight Son]

Originally Posted by betwys1

In seas in excess of 20 feet with winds gusting more than 50 knots, she will roll 25-35°, and occasionally roll in excess of 40°.
Stavradis, Proc. Vol. 113/1/1,007 USNI

Ah, who to believe: who to believe? Lieutenant Commander James Stavridis, U. S. Navy, or Midnight Son, Member CF, in good standing. <g>

So he and I agree, it will roll, and only the radar crew will know for sure, if it would lose lock. I highly doubt it.
Best wishes.

[Davidhoy]

Originally Posted by Brian.D

Oh and I wish people would stop using the term "speed of light". Just say it tracks very fast.

This ^^
The RF transmissions are speed of light (or close to it), but the antenna beam forming is way slower. Still a heck of a lot faster than the mechanically steered antenna systems I worked on at KVH years ago. Those antennas had slew times measured in seconds, the Starlink phased array antennas slew in milliseconds. As long as the antenna can be pointed in the general direction of the satellites, it will/should be able to track pretty easily, particularly if it has any kind of signal strength feedback loop to allow it to feed into the beam forming calculations.

[Tenedos]

It has been a while since this the last post on this thread and there has been some developments on the Starlink front. Has anyone had success to use Starlink at a marina (or preferably at anchor) reliably?

[bcboomer]

We're using ours in a marina and hope to use it up the Sunshine Coast this spring. Last summer it disconnected about 7 Nm down the river from the marina.

There is a user posting on Reddit and Facebook who has used it successfully all over the US and Canada on his RV. Yesterday he posted that he is now getting a connection without changing his registered location. He says that there has been a software update that allows roaming without loosing your home location.

If it is a permanent change it will be a game changer because there are cells up the Salish Sea.

At this time you shouldn't use it while moving because that is a contravention of SpaceX licences. We don't want their competitors complaining to the powers that be.

[Tenedos]

Originally Posted by bcboomer

If it is a permanent change it will be a game changer because there are cells up the Salish Sea.

At this time you shouldn't use it while moving because that is a contravention of SpaceX licences. We don't want their competitors complaining to the powers that be.

We are in Salish sea too! We are south of the border though and intend to cross to Canada in spring. My understanding is you cannot carry a Starlink unit from US to Canada or one country or another. Do you know if that is the case?

Also, when you say "while moving", you mean while underway or while you are at anchor? You are (at least we are) kinda moving while at anchor too :-) Any experience on the performance while at anchor?

[Statistical]

Originally Posted by Tenedos

We are in Salish sea too! We are south of the border though and intend to cross to Canada in spring. My understanding is you cannot carry a Starlink unit from US to Canada or one country or another. Do you know if that is the case?

Also, when you say "while moving", you mean while underway or while you are at anchor? You are (at least we are) kinda moving while at anchor too :-) Any experience on the performance while at anchor?

While underway. SpaceX doesn't have ESIM (Earth Station In Motion) license and the current hardware is not certified for it. Current hardware and license is only for FSS (Fixed Satellite Service).

In fact the upper end of their band is not authorized for it so SpaceX has requested an exemption from policy rules. That makes it a lot less straight forward and requires public comment and a chance for competitors to get their lobbying dollars worth in obstructing.

[bcboomer]

You need to buy your dish designated for the country you want to use it in. I think the guy in the RV sells his dish each time he changes back and forth between Canada and the US. Maybe you could buy 2 and just change your designated dish back and forth.

As far as motion is concerned I would consider an anchored or moored boat as being in a fixed location.

[Tenedos]

Originally Posted by bcboomer

As far as motion is concerned I would consider an anchored or moored boat as being in a fixed location.

Did you try yours at anchor? How does it perform?

[Tenedos]

Originally Posted by bcboomer

You need to buy your dish designated for the country you want to use it in. I think the guy in the RV sells his dish each time he changes back and forth between Canada and the US. Maybe you could buy 2 and just change your designated dish back and forth.

Also, looks like ordering a Canadian dish in the US seems to be a no-go, requires a Canadian address. Sigh, i hope this was easier. In the meantime, if someone wants to sell their Canadian dish, let me know

[bcboomer]

Originally Posted by Tenedos

Did you try yours at anchor? How does it perform?

No, we're in a marina on a river and last summer it wouldn't work past 7Nm down the river.

Based on how well it works in storms with the dish rocking back and forth pretty quickly I don't expect any problem at anchor. This thing focuses in milliseconds.

Order to delivery time can be a long wait unless you find an open cell. We got ours more than a year ago but had to wait for the cell we're in to get more capacity. We had ordered it to a street address 30 km away and that spot had space.

If you look at the facebook and reddit groups specific to RV use you may learn of some creative ways to get a Canadian address.

[Jon Hacking]

Originally Posted by Davidhoy

... As long as the antenna can be pointed in the general direction of the satellites, it will/should be able to track pretty easily, particularly if it has any kind of signal strength feedback loop to allow it to feed into the beam forming calculations.

Interesting thought, David. I've been thinking that it would need accelerometers (as well as its current GPS & fluxgate compass) to decide which way it was moving/pointing, & then use that to decide which way to point its beam (after some fairly hairy calculations to figure out where the bird is in 3D space). I was thinking it would have to do this hundreds of times/sec to keep the beam locked on while the boat (RV/car/plane) is moving underneath it, given our motion while underway.

There's no feedback signal per se, but I suppose it could measure signal strength, move the beam a bit, take another reading, & move the beam a bit more, take another reading, etc. That also takes significant time, but it might be fast enough. It also depends on the signal from the bird remaining constant while it's whizzing along at 27,000 Km/hr, or 7.5 Km/sec. The main problem with this approach is that it's all too easy to get off on a side-lobe instead of the main beam. Believe me, I've been there.

Maybe a hybrid approach, where the initial direction is set from readings of accelerometers, GPS, fluxgate compass, & calculations of where the bird is (to make sure it's on the main lobe), followed by smaller iterations based on received signal strength? That would have the computer & sensor HW working pretty flat-out, but I guess it doesn't take much to run that stuff.

Does anyone know what the 3db beam-width of Dishy is? According to this article, for an array of 1,000 elements, it's about 3 degrees (if I'm reading it correctly - it's been a LONG time since I played this game).

You need to buy your dish designated for the country you want to use it in.

Musk has promised that it would work on "boats". He didn't specify size of boat, but boats cross international borders, especially the big ones he's primarily interested in. Planes & RVs do as well, & once these things get fitted into the roofs of Teslas, I'm sure many of those will want to cross international borders, especially in Europe. While I don't think it will ever be as portable as an Iridium, it can be made portable enough for our purposes.

Once StarLink gets its Earth Station In Motion license, I think the country restrictions will go away. Hope so, anyway, as it would be pretty silly to leave them on.

I only started getting into this game in 2001, when we bought our Iridium. I don't remember Iridium having to go through all these shenanigans. Why is StarLink having to jump through all these hoops?

[goboatingnow]

Originally Posted by Jon Hacking

Interesting thought, David. I've been thinking that it would need accelerometers (as well as its current GPS & fluxgate compass) to decide which way it was moving/pointing, & then use that to decide which way to point its beam (after some fairly hairy calculations to figure out where the bird is in 3D space). I was thinking it would have to do this hundreds of times/sec to keep the beam locked on while the boat (RV/car/plane) is moving underneath it, given our motion while underway.



There's no feedback signal per se, but I suppose it could measure signal strength, move the beam a bit, take another reading, & move the beam a bit more, take another reading, etc. That also takes significant time, but it might be fast enough. It also depends on the signal from the bird remaining constant while it's whizzing along at 27,000 Km/hr, or 7.5 Km/sec. The main problem with this approach is that it's all too easy to get off on a side-lobe instead of the main beam. Believe me, I've been there.



Maybe a hybrid approach, where the initial direction is set from readings of accelerometers, GPS, fluxgate compass, & calculations of where the bird is (to make sure it's on the main lobe), followed by smaller iterations based on received signal strength? That would have the computer & sensor HW working pretty flat-out, but I guess it doesn't take much to run that stuff.



Does anyone know what the 3db beam-width of Dishy is? According to this article, for an array of 1,000 elements, it's about 3 degrees (if I'm reading it correctly - it's been a LONG time since I played this game).





Musk has promised that it would work on "boats". He didn't specify size of boat, but boats cross international borders, especially the big ones he's primarily interested in. Planes & RVs do as well, & once these things get fitted into the roofs of Teslas, I'm sure many of those will want to cross international borders, especially in Europe. While I don't think it will ever be as portable as an Iridium, it can be made portable enough for our purposes.



Once StarLink gets its Earth Station In Motion license, I think the country restrictions will go away. Hope so, anyway, as it would be pretty silly to leave them on.



I only started getting into this game in 2001, when we bought our Iridium. I don't remember Iridium having to go through all these shenanigans. Why is StarLink having to jump through all these hoops?

Iridium also ran into considerable legal hurdles


As to why anyone would want to physically move ie gimbal , a phased array unit , is beyond me.

[Yojimbo]

Haven't tried to insert a link here before- this may have some relevancy for offshore hopes of connectivity.

https://fortune.com/2022/02/10/space...%20the%20fleet.

An article in Nov. 21 Harpers expands on upper atmosphere traffic.

[Statistical]

Originally Posted by Jon Hacking

I only started getting into this game in 2001, when we bought our Iridium. I don't remember Iridium having to go through all these shenanigans. Why is StarLink having to jump through all these hoops?

Everyone I mean everyone has to go through these shenanigans. At one time in flight wifi cutoff when you went into Chinese airspace because OrbComm hadn't been certified by Chinese regulators. Even today Iridium doesn't work in all countries (granted not places you likely want to go).

Satellite connectivity due to its nature of crossing national borders and yet being regulated by those nations has always been a complicated mess. Iridium only seems plug and play and work everywhere like magic because the company has spent 30+ years making that happen.