Iridium vs Globalstar satellites

[mtwarden]

Thought this might be of interest to some folks. Garmin and Zoleo use Iridium satellites, Apple and Spot use Globalstar. From testing by backpackinglight.


Globalstar remains constrained by the fact that its satellites can't talk to each other - they have to talk to ground stations. Globalstar has 25 satellites in orbit (and 17 more on the way soon), and another 27 ground stations. But if you get your message up to a Globalstar satellite, it has to hang on to it until it "sees" a ground station, and that can take some time. If it takes too much time, your message drops (send failure).

Iridium, on the other hand, relies on a true "mesh" network - its satellites talk to each other and (quickly) bounce your messages around, until it reaches the one closest to Tempe, AZ, where it's main ground station is located.

The result? Faster message delivery and more reliable communications.

This performance is magnified in heavy tree cover or in canyons. Here, Iridium has an edge as well, because of its 66 operational satellites currently in the sky.

This is why we lean towards recommending Iridium-based satellite messaging devices.

 

[z987k]

Thought this might be of interest to some folks. Garmin and Zoleo use Iridium satellites, Apple and Spot use Globalstar. From testing by backpackinglight.


Globalstar remains constrained by the fact that its satellites can't talk to each other - they have to talk to ground stations. Globalstar has 25 satellites in orbit (and 17 more on the way soon), and another 27 ground stations. But if you get your message up to a Globalstar satellite, it has to hang on to it until it "sees" a ground station, and that can take some time. If it takes too much time, your message drops (send failure).

Iridium, on the other hand, relies on a true "mesh" network - its satellites talk to each other and (quickly) bounce your messages around, until it reaches the one closest to Tempe, AZ, where it's main ground station is located.

The result? Faster message delivery and more reliable communications.

This performance is magnified in heavy tree cover or in canyons. Here, Iridium has an edge as well, because of its 66 operational satellites currently in the sky.

This is why we lean towards recommending Iridium-based satellite messaging devices.

Globalstar is also only a 52 degree inclination orbit. The more north you go the more towards the southern horizon the line of sight to the satellite is until there is no line of sight at all. This is made worse if there is terrain to your south.
Iridium uses polar orbits where your latitude doesn't matter.

 

[mtwarden]

Back in the day we had a couple of Globalstar Sat phones; I’m sure it’s better now, but those phones were not very good (I think the phones were probably fine, satellites not so much).

 

[GunsAreFun]

Until iPhone can send and receive messages and SOS passively without murdering my battery, I’ll continue carrying an inreach.

Being able to push SOS and know a message will eventually get out or receive a message from my family for an emergency even if I’m not deliberately connecting to a satellite is a big deal.

 

[yfarm]

The globalstar shortcomings have been well known for some time via their sat phone issues. I find it curious that Apple chose Globalstar as their partner, it is inconceivable that the engineers were not aware of this. How could Apple have made such a mistake unless they were made aware of significant changes to Globalstars system that no one is aware of. I remain a Garmin customer for the forseeable future. As an aside, in September I was at a trailhead east of Ridgway Co, at about 10,800 ft in a bowl about a mile across surrounded by peaks of 12-13k. Would periodically lose satellites on my Garmin resulting in delays of text tramsmission by several hours, assumed due to peaks blocking the view. Had never happened before using the Inreach for several years.

 

[mtwarden]

Evidently Apple is investing in Globalstar and adding more satellites. That probably will help, but sounds like the Iridium system is simply better.

 

[IDVortex]

I've actually started researching sat phones, especially if I can go on a goat hunt. For my wifes piece of mine. As of right now, I'm leaning more towards the iridium sat phones.