Musk says Starlink will work on boats

[CruiseDucati]

In the 90's we could transfer packets to and from the Mir spacecraft with a tracking program, a handheld 1 watt VHF radio and a handheld Yagi.

[GordMay]

Originally Posted by CruiseDucati

In the 90's we could transfer packets to and from the Mir spacecraft with a tracking program, a handheld 1 watt VHF radio and a handheld Yagi.

Greetings and welcome aboard the CF, Ducati.

Indeed.
Contacting The Mir Orbital Complex ➥ https://www.qsl.net/kd4cga/mir1.htm
How to hear the ISS ➥ https://amsat-uk.org/beginners/how-to-hear-the-iss/

[disputin]

Steven Mitchell at Seabits had a pretty good review. The problem will keeping the satellite dish pointed at the satellite as the boat is moving.



https://seabits.com/using-starlink-a...d-in-a-marina/


Sean

[aqfishing]

Lets hope the come up with an affordable gyro antenna. I would happily pay a fair bit for an antenna in order to get cheap worldwide internet, especially in the middle of the ocean!

And not for social media etc.

Weather !!! Amongst other important things!

[Franziska]

Originally Posted by aqfishing

Lets hope the come up with an affordable gyro antenna. I would happily pay a fair bit for an antenna in order to get cheap worldwide internet, especially in the middle of the ocean!

And not for social media etc.

Weather !!! Amongst other important things!

As far as I understand it does not need a mechanical gyro.
The Starlink antennas achieve this electronically.

[wholybee]

Originally Posted by Franziska

As far as I understand it does not need a mechanical gyro.
The Starlink antennas achieve this electronically.

They quite possibly will, simply by applying simple geometry. I don't recall offhand the angle the array can see. Let's assume/guess it is 120 degrees. It is probably less than that.

If it can see 120 degrees, that means that as a satellite rises from the horizon, the dish can't see it until it is 30 degrees up, and will lose it as it dips below 30 degrees. If your boat is heeled over at 10 degrees, that changes to 40 degrees and 20 degrees. So, what happens when a rising satellite is at 35 degrees? Consider also that the satellites also have phased antennas to place a spot on your cell. So, one can't just assume that the dish will stay locked on the satellite that is at 25 degrees. Any abnormal tilting of the dish would need to be communicated to the satellites so the satellite could keep the beam on the cell when it might otherwise not be necessary.

Also, the dish doesn't point straight up in the air, but is tilted optimally toward the best direction to see the satellites. What happens when the boat turns, and the dish is pointed away from that direction?

[CruiseDucati]

Originally Posted by GordMay

Greetings and welcome aboard the CF, Ducati.

Indeed.
Contacting The Mir Orbital Complex ➥ https://www.qsl.net/kd4cga/mir1.htm
How to hear the ISS ➥ https://amsat-uk.org/beginners/how-to-hear-the-iss/

TV comms with the Shuttle was achieved with a tracking yagi and a mobile radio. Tnx for the welcome aboard. 73's
AC6BT

[trifan]

Originally Posted by CruiseDucati

In the 90's we could transfer packets to and from the Mir spacecraft with a tracking program, a handheld 1 watt VHF radio and a handheld Yagi.

Yeah but if I remember correctly there was no way in hell back then to run 100Mb/s like Starlink does now. Baby steps. Gotta crawl before you can walk.

[Jon Hacking]

Lets hope they come up with an affordable gyro antenna.

They quite possibly will, simply by applying simple geometry.

There appear to be some misconceptions about the StarLink antenna (known internally as "Dishy McFlat Face").

It's not really a "dish" in the normal sense, where a "feed" at the focus of a parabolic dish transmits (& receives) energy that reflects off the dish, which focuses the energy into a beam.

Dishy, despite the name, isn't a dish at all. It's a flat array of over 1,000 transceiver elements. By feeding the signal to the elements on the right side of the array infinitesimally ahead of when you feed the elements to the left, the beam will go off to the left.

Using this mechanism, the beam can be redirected (steered) in single digits of milliseconds (or even microsecs) without ever moving the platform (dish). This is plenty fast enough to compensate for the motions of the boat.

One problem is instrumentation. Dishy has an internal GPS & presumably has (or will have) accelerometers that work in 3-axes, either roll/pitch/yaw or x/y/z (or maybe all 6). So the software has to read all of these sensors to know how the orientation of Dishy is changing while the boat moves under it. The SW can also work out where each satellite is in absolute space, & can then work out where the bird it's talking to is relative to the boat, but this involves some pretty hairy spherical (hyperbolic) trigonometry, with long, dangly strings of relevant digits.

Only once the SW has read the sensors & worked out all the trig can it decide where to aim the beam. And it has to do that about 100x/sec. Dishy's computing power is about that of a good smart-phone, so I'm hopeful the SW won't be the bottleneck, but the sensors could well be.

The SeaBits article is correct that the current sensor/SW can't do that today. But the system is supposed to eventually work for RVs on winding, bumpy roads, as well as planes in turbulence. Hopefully that will be good enough for us cruising boats as well.

Cruising boats also need a few more items that aren't currently provided:

1. The ability of the system to track us as we move outside our assigned cell. Right now, you sign up with a fixed address, & StarLink will then keep a satellite's beam on your cell 24/7. But that won't work for any mobile users, so presumably the system will eventually allow for us to move out of our cell, & track us as we do so.
   .
2. The satellite laser interconnects. At present, the satellite that's handling your data can't talk to other satellites, so it has to, itself, be able to talk to a ground station. This is much like the old GlobalStar system. But since the birds aren't very high, they can't see very far, so ground-stations (with good internet connections) are needed every few hundred miles. Yet most of those ground-stations will become obsolete once the birds can talk to each other, so StarLink may be dragging its feet a bit building them. StarLink has only recently started sending up birds with the laser interconnects, but has said that all future birds will have them. Since lasers in space are faster than fiber on the ground, StarLink is hoping that most of the data will go over the laser links before going down to a ground-station.
   .
3. Lower power. Dishy currently consumes about 100W, or 8A at 12v. This is more than most cruising boats will want to leave on for very long. Hopefully the power requirements will come down with later versions.

[redneckrob]

Originally Posted by Jon Hacking

There appear to be some misconceptions about the StarLink antenna (known internally as "Dishy McFlat Face").

It's not really a "dish" in the normal sense, where a "feed" at the focus of a parabolic dish transmits (& receives) energy that reflects off the dish, which focuses the energy into a beam.

Dishy, despite the name, isn't a dish at all. It's a flat array of over 1,000 transceiver elements. By feeding the signal to the elements on the right side of the array infinitesimally ahead of when you feed the elements to the left, the beam will go off to the left.

Using this mechanism, the beam can be redirected (steered) in single digits of milliseconds (or even microsecs) without ever moving the platform (dish). This is plenty fast enough to compensate for the motions of the boat.

One problem is instrumentation. Dishy has an internal GPS & presumably has (or will have) accelerometers that work in 3-axes, either roll/pitch/yaw or x/y/z (or maybe all 6). So the software has to read all of these sensors to know how the orientation of Dishy is changing while the boat moves under it. The SW can also work out where each satellite is in absolute space, & can then work out where the bird it's talking to is relative to the boat, but this involves some pretty hairy spherical (hyperbolic) trigonometry, with long, dangly strings of relevant digits.

Only once the SW has read the sensors & worked out all the trig can it decide where to aim the beam. And it has to do that about 100x/sec. Dishy's computing power is about that of a good smart-phone, so I'm hopeful the SW won't be the bottleneck, but the sensors could well be.

The SeaBits article is correct that the current sensor/SW can't do that today. But the system is supposed to eventually work for RVs on winding, bumpy roads, as well as planes in turbulence. Hopefully that will be good enough for us cruising boats as well.

Cruising boats also need a few more items that aren't currently provided:

1. The ability of the system to track us as we move outside our assigned cell. Right now, you sign up with a fixed address, & StarLink will then keep a satellite's beam on your cell 24/7. But that won't work for any mobile users, so presumably the system will eventually allow for us to move out of our cell, & track us as we do so.
   .
2. The satellite laser interconnects. At present, the satellite that's handling your data can't talk to other satellites, so it has to, itself, be able to talk to a ground station. This is much like the old GlobalStar system. But since the birds aren't very high, they can't see very far, so ground-stations (with good internet connections) are needed every few hundred miles. Yet most of those ground-stations will become obsolete once the birds can talk to each other, so StarLink may be dragging its feet a bit building them. StarLink has only recently started sending up birds with the laser interconnects, but has said that all future birds will have them. Since lasers in space are faster than fiber on the ground, StarLink is hoping that most of the data will go over the laser links before going down to a ground-station.
   .
3. Lower power. Dishy currently consumes about 100W, or 8A at 12v. This is more than most cruising boats will want to leave on for very long. Hopefully the power requirements will come down with later versions.

Besides power consumption not being an issue for any but a tiny niche of Starlink users, and therefore probably vanishingly low on the priority list, the amount of processing required may also make it hard to reduce it by much.

[Chotu]

Originally Posted by redneckrob

Besides power consumption not being an issue for any but a tiny niche of Starlink users, and therefore probably vanishingly low on the priority list, the amount of processing required may also make it hard to reduce it by much.

Also, reading everything that John wrote just above that you quoted, there is no chance that the power consumption will be going down on boats. If anything, it has to go up.

The calculation he’s talking about to track the satellites in absolute space, to phase vary the array... That means it’s going to run at the full 100W that it is rated for. Because it’s going to be doing those calculations hard-core and nonstop as the boat is continuously moving. There is no room for saving power in a continuously moving application that works that way. On land, you could certainly save some power with the array antenna being absolutely motionless relative to the planet. But not when it’s continuously in motion

[GordMay]

Cat on a hot satellite dish: Elon Musk’s Starlink antenna hits surprise problem
Starlink’s satellite internet performance has fallen victim to felines attracted to the warmth its dish gives off on cold days.
Starlink, Elon Musk’s internet company, has more than 1,600 outdoor satellites orbiting through space. However, some of the earthbound Starlink satellite dishes are having an internet speed problem. The satellite dishes have a self-heating feature, which works great at melting snow—but may be why cats are huddling on them to warm up, the Guardian reports.
More ➥ https://www.theguardian.com/technolo...cats-elon-musk

[Jon Hacking]

Thanks for this, Gord. An adorable photo of 5 cats snuggled together on a Dishy in the snow has been circulating around FB for a while now, with comments about connecting your Dishy with Cat-5 cabling.

I'm not sure if Dishy actually has a heating circuit, or if v1 Dishy simply dissipates enough power to keep the dish warm. I was thinking the latter, but we cruise in the tropics, so don't think about ice much.

But the new, rectangular Dishy (Dishy McSquare Pants?) draws significantly less power. Reports I've seen, mostly from RVers, who also care about power, say it's usually down around 40W, or about 3.5A@12v (although it seems to vary as new SW revisions are pushed out).

This is certainly more palatable for us power-stingy cruisers. I wouldn't want to leave it on 24/7, but leaving it on for several hours/day wouldn't be that big a deal (for us, but we have 1200W of solar). So power usage appears to be something that StarLink is thinking about.

While its true that running microprocessors faster consumes more power, I suspect that this is only a minor part of the User Terminal's power usage. The vast majority of the power is probably going into the beam, as making microwaves is pretty inefficient.

There have also been some articles circulating about how to run the whole thing from 12v without actually having to run an inverter, but they get more complicated, & most involve splicing into the proprietary cabling.

[goboatingnow]

phased arrays are not known for their low current consumption !!

I would suspect that moving platforms is well down the list of priorities for Starlink , commercial operators already have some options albeit at a high price and the number of mobile users not using cell systems is therefore quite small. I suspect it will be some time ( if ever) before a solid solution is available

[Jon Hacking]

Originally Posted by goboatingnow

I would suspect that moving platforms is well down the list of priorities for Starlink, commercial operators already have some options albeit at a high price and the number of mobile users not using cell systems is therefore quite small. I suspect it will be some time (if ever) before a solid solution is available

Boating, you've been surprisingly negative about StarLink for a while, especially given your tagline.

Pretty much all bigger ships have, & presumably use, sat-com domes, which, as you correctly point out, are considerably more expensive than StarLink, both to buy & to operate. I'd think that those shipping companies would save a BUNDLE on StarLink when compared to their current geostationary setups, & smaller shipping lines would want in as well, since the prices are so much lower than those other options. That's not a huge market, but it's pretty sizeable.

There are a TON of RVs out there, & they'd all like a mobile solution that works anywhere. They've got a lot more vibration than we do.

Commercial planes will need a different antenna entirely, probably a skin-mounted phased array. They're probably a comparably sized market to ships, & StarLink has promised them a solution, despite having to design & build an entirely new antenna for them.

I won't try to 2nd guess Musk, but there's a sizable market for mobile connectivity (as you should know). I'm keeping the faith.