Free wifi

[CurlerRob]

26 minutes ago, longterm said:

Also, being in the middle of the ocean has no effect on an Internet service that relies on satellites, so it shouldn't matter *where* the ship is when it's using a satellite connection. Having said that, I don't know how well the satellite(s) cover the globe, so there may be areas where connectivity is weak or non-existent, but I can't speak to that.

@longterm, it does matter where you are on the globe. Most satellites used are in a geosynchronous orbit (appearing stationary from earth) and located in reasonable proximity to the equator.

 

As you move to higher latitudes (Arctic or Antarctic), the satellites appear lower and lower on the horizon and the signal strength is reduced. It's analogous to an overhead sun feeling much warmer than a setting / rising one. Service in the far north and south is challenged at best.

 

The other issue is that satellite connectivity is line of sight - just being in a fjord with high cliffs can block the signal (see Norway or Chile). This is especially noticeable at high latitudes as well. 🍺🥌

[longterm]

3 hours ago, CurlerRob said:

@longterm, it does matter where you are on the globe. Most satellites used are in a geosynchronous orbit (appearing stationary from earth) and located in reasonable proximity to the equator.

 

As you move to higher latitudes (Arctic or Antarctic), the satellites appear lower and lower on the horizon and the signal strength is reduced. It's analogous to an overhead sun feeling much warmer than a setting / rising one. Service in the far north and south is challenged at best.

 

The other issue is that satellite connectivity is line of sight - just being in a fjord with high cliffs can block the signal (see Norway or Chile). This is especially noticeable at high latitudes as well. 🍺🥌

Well, if that were the case, (and I know nothing about satellite orbit paths), how come I can use my car's satellite radio in north Texas or elsewhere, without any issues? I've driven north and still had good satellite connectivity on my car radio, and I do know that there are DirecTV subscribers in northern US and Canada.

Perhaps there are multiple satellites on different paths? I'm asking this knowing absolutely nothing about satellite paths, but it seems doubtful that the only place satellites are reliable would be along the equator. I have to think that there are multiple satellites (probably dozens for this one company) using different orbital paths; please correct me if I'm missing something here...

 

 

 

[longterm]

39 minutes ago, longterm said:

Well, if that were the case, (and I know nothing about satellite orbit paths), how come I can use my car's satellite radio in north Texas or elsewhere, without any issues? I've driven north and still had good satellite connectivity on my car radio, and I do know that there are DirecTV subscribers in northern US and Canada.

Perhaps there are multiple satellites on different paths? I'm asking this knowing absolutely nothing about satellite paths, but it seems doubtful that the only place satellites are reliable would be along the equator. I have to think that there are multiple satellites (probably dozens for this one company) using different orbital paths; please correct me if I'm missing something here...

 

 

 

This topic got me wondering about satellites' orbital paths, and I found this on NASA's website:
 

"Satellites can orbit Earth's equator or go over Earth's North and South Poles . . . or anything in between. They orbit at a low altitude of just a few hundred miles above Earth's surface or thousands of miles out in space.

The choice of orbit all depends on the satellite's job."

So I guess this means that cruise ships' satellites probably orbit on all sorts of paths in order to service cruise ships that go all over the globe...

[CurlerRob]

3 hours ago, longterm said:

Well, if that were the case, (and I know nothing about satellite orbit paths), how come I can use my car's satellite radio in north Texas or elsewhere, without any issues? 

Didn't mean to confuse you ... many communication satellites are launched such that they orbit earth at or near the equator and at an altitude such that they orbit in the same time that the earth rotates (~24 hours). That means that as seen from the ground, the satellite appears to stay in the same place in the sky - which makes it easy to aim a ground-based antenna (receiver). To provide global coverage, there are  multiple satellites in different spots around the orbital 'circle', each looking like it 'sees' a different portion of the earth.

 

Although they are orbiting at or relatively near to the equator, they all cover large amounts of territory due to their altitude. For example, a satellite that appeared to be stationary on longitude 100 W (which bisects Texas) might cover an area from southern Mexico to northern Canada - they are not limited only to a narrow area directly 'under' them.

 

When I referred to 'high latitudes' I was referencing places such as northern Norway and the high arctic, or the tip of South America / Antarctica. Think of a person holding a flashlight at night - the light (signal) is brightest (strongest) when you are directly in front of (under) it, but you can still see the light as you move farther to the side - it just gets dimmer and dimmer until it ultimately is too faint to see. That's the analogy for high latitudes.

 

If you were interested enough to look up the NASA site, this one has a brief article that may help with the idea of geosynchronous orbits: What Is a Geosynchronous Orbit? | Space   Cheers! 🍺🥌

[Heidi13]

4 hours ago, longterm said:

Well, if that were the case, (and I know nothing about satellite orbit paths), how come I can use my car's satellite radio in north Texas or elsewhere, without any issues? I've driven north and still had good satellite connectivity on my car radio, and I do know that there are DirecTV subscribers in northern US and Canada.

Perhaps there are multiple satellites on different paths? I'm asking this knowing absolutely nothing about satellite paths, but it seems doubtful that the only place satellites are reliable would be along the equator. I have to think that there are multiple satellites (probably dozens for this one company) using different orbital paths; please correct me if I'm missing something here...
 

 

The older SatNav and current GPS sats are in various orbits, but the INMARSAT sats, which are used by shipping companies for communications, are as per how Rob explained.

 

TV satellites are beamed to a specific area. Can't speak for Direct TV, but our new Shaw sats can be beamed with limiting latitudes, so we cannot receive the signal more than about 200 miles into the USA. Your DirecTV is probably also only broadcasting to the N/Hemisphere.

 

The INMARSAT sats are broadcasting and receiving at all Latitudes, both north & south. These are also Tx/Rx, whereas your Sat radio and TV are transmit only, so are not comparable.