I’m planning a Caribbean Cruise for later this year. If I take my Sirius receiver onto the ship with me, will it work? I’d love to be able to dig some jazz while laying on the deck.
Here’s a coverage map. It’s not from the Sirius web site though, no idea how accurate it is…
It worked in the south east corner of Cuba.
I don’t think so. Can a standard radio (like in your car) get reception in the middle of the sea? If so, then yes, I guess - The receiver works on standard radio frequencies.
I may be spectacularly wrong.
Joe
You are. 
Its from a satellite. It covers most of the Caribbean. I was able to get a signal in eastern Cuba.
Well, Sirius transmits from a satellite. The receiving antenna needs to be able to ‘see’ the satellite: it needs to be out in the open or at most behind a thin covering.
Does the satellite transmit in the direction of the places the OP will be cruising?
As far as I know it’s in geostationary orbit (so that would put it over the equator) and beaming its signal north (so it will hit the continental US + Canada). I’ll be in the Caribbean, and since the Caribbean is north of the equator, I think it should work.
Well, duh 
But for my reciever, I have to be able to tune into a standard station with no signal…
Oh, shit. Never mind :smack:
I’m officially a dumbass. But just for the purposes of this thread.
Joe
Actually no. I was surprised at this. There are actually three satellites and they do loops around North and South America. Only two are broadcasting to North America at a time. They don’t claim service in South America so I guess they turn them off. Wiki has a map of the satellite path.
Depends on if it’s water-proof. 
If you take your car on the cruise then you should have no problem finding a freq with no signal.
Sometimes you just want to be able to delete your posts.
Ex-Nasa satellite guy checking in here…
geostationary orbit refers more to the distance from earth then the location. Roughly 23,000 miles.
The entire sphere at that distance is available for the satellites. Where you want to park one depends on your application and the equipment on board.
Most TV satellites serving North America are located somewhere over the east of Brazil if I recall correctly. Sirius probably has a nearby position.
Look at the map in the above linked wiki article and let me know what you think (post 9). It is a lot different than what you describe.
The Sirius satelliets are in geosynchronous orbit, but not in geostationary orbit.
A geostationary orbit is a circular orbit, above the equator, with an orbital period of 24 hours. Which means it rotates with the earth; its position relative to the earth is fixed. You can maintain contact with a geostationary satellite with a fixed antenna. Which is why most communications satellites (including satellite TV broadcast satellites) are in geostationary orbit. One disadvantage is that the satellite must be above the equator; this means at higher latitudes, the satellite is very low in the sky.
A geosynchronous orbit is any orbit with a 24-hour orbital period. It comes back to the same position (relative to the earth) every 24 hours. If the orbit is circular but tilted, seen from the earth it appears to move back and forth in the north/south direction. If the orbit is ellitptical, it moves faster when it’s closer to the earth so it gets further ahead in its orbit, so it moves east/west in the sky. If it’s both tilted and elliptical it will follow a lopsided figure-8 path in the sky.
A radio brodcast satellite doesn’t need to be in geostationary orbit because satellite radio receivers don’t use directional antennas. It doesn’t matter if the satellite moves around in the sky, as long as the antenna has a clear line of sight to the satellite.
Still, if you only had one broadcast satellite, it would make sense to have it in geostationary orbit, because if it was in an inclined orbit, part of the time it’ll be south of the equator, and therefore even lower in the sky. But Sirius uses multiple satellites (3?). They are in different tilted orbits so at any given time, at least one of them is north of the equator. This means for all North American customers, the broadcasting satellite is higher up in the sky than a geostationary satellite would be.
Yeah I saw that after my post.
I was hoping someone else would take the time to write what scr4 did. I’d go with that with one caveat.
It has been a long time (decades) since I did the physics of orbits, but it seems to me that a geostationary orbit need not be over the equator.
The idea is that the satellite appears from earth to be hovering. If I am thinking clearly today (No guarantee), that can be accomplished anywhere. I’d say that to avoid precession, you’d want the orbit to be perpendicular to the tilt of the axis the earth rotates on (which is roughly parallel with the equator) but you don’t need to be over it.
You could park over a the North Pole for instance, and the orbit would basically be spinning in place. Over the equator, you’d have to go all the way around the earth.
In between those extremes, the circumference of the orbit would vary. Your calculus book will explain why and how
I will leave it for others to explain why most geostationary orbits are at the magic altitude of ~23K miles, but I will say that if you have sufficient means of propulsion it doesn’t necessarily have to be so.
Of course you can’t simply refuel if you run out, but I would not be surprised in the least to find out some country has nuclear powered military satellites in a low geosynchronous orbit that they can move to be over hotspots and stay there as needed. If you can live with limited fuel and a limited mission lifetime, that would not be an operational problem.
A satellite that stayed directly over the North Pole would not so much orbit as plummet.
Every orbit goes around the center of gravity of the object it’s orbiting. (You could hover like a helicopter, using rockets instead of rotors, but that’s not really orbiting and the energy cost would be enormous.) Orbits go all the way around the Earth. An object in orbit either stays over the equator, or crosses it twice each time around.
Sirius customer support might know.**
The center of a circular orbit is at the the center of earth. (And an elliptical orbit has one of its foci at the center of the earth.) If a satellite were fixed above anywhere other than the equator, the center of orbit will not be the center of the earth.
You can hover over any spot on the earth, but I wouldn’t call that an orbit. Nobody would consider a helicopter to be in orbit.
I’d say that’s implausible. Even a nuclear thruster needs propellant, which would be used up quite fast if you tried to use it to hover. It’s far more efficient to use either multiple satellites in low-earth polar orbit, or use some type of unmanned aircraft. There’s some research into high-altitude unmanned blimps, for example.
Whuuuuuuu . . . ? Color me ignorant but I was under the impression that Sirius covered most of the world. I’m 99% sure that someone on the Stern Show (possibly a caller, though) went to Africa and said it worked there, but I guess it’s possible they could’ve been listening on the internet. I’m also pretty much 100% sure that Stern has listeners in the UK. I guess it’s also possible that they listen on the net but seems weird.
You beat me to it. I was going to say everything you just said. By that coverage map earlier, I would also assume they must turn off the signal over South America.
I was going to mention the XM Sirius merger and the fact that XM has 2 birds in geostationary orbit over the equator which Sirius (and the OP) might benefit from, but I was way outta date. This wiki page about the merger says there are no details as to whether they can use each other’s satellites, but it also say XM has 4 satellites, apparently XM4 is in elliptical geosynchronous orbit.
Is it typical for elliptical orbits to gain and lose such altitude, or do they possibly do it to give better reception at their low point over the US? Maybe Sirius can’t offer service to South America because their satellites use a similar orbit and can’t beam a good signal that far?