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Comment by user3939382 | Hacker News Reader

Wait, what? iPhones are sat phones?? It has the antenna for that?? Since when? The GPS is a passive receive. I skimmed the article and didn't see, how on Earth (lol) does this work? Sat antennas are huge. Maybe these search and rescue SOS beacons have their own signal?

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New this year. The phone basically guides you to point it at the satellite (and turn as necessary), which is why it doesn’t need a big antenna.

It’s not as good as a Garmin or some such, but you have it with you.

You have to point the phone at the sky for long periods of time AND track the sat position in the sky while you do it. It's probably some long spread spectrum approach (lots of processing gain), as well as I'm sure a bunch of other cool tricks/techniques.

There are obviously people out there that are deep experts on radio, signals, propagation, antennas, etc. That's not me, but I know enough about it to appreciate that this is completely amazing.

Does anyone know how they track the position of the communication satellites? I assume they use GPS for the users position, the gyro and accelerometer for device orientation, and then periodically load and update the LEO sat paths on the device when they are connected. Or is the antenna able to estimate LEO position via a signal the LEO sats sends out?

Yeah, no different than a stargazing app where you point your phone and it labels the stars that show up in the view.

Just need the x,y,z, compass and gps coordinates.

The positions of the satellites are well known and documented. Fun fact..on the Garmin fenix watches, it is recommended that you synch your watch with your Garmin Connect app every few days (week) so that you download the latest satellites position file, which significantly improves the GPS lock time with the satellites before you begin an activity.

As others have stated, I don't think Apple's product will really erode Garmin's market share for several years. The lack of detailed topo maps and applications will severely hamper them.

With Apple latest shift, I see their ecosystem as a very strong contender for business travel (international news reporter?) that requires strong security (lockdown mode), ability to communicate in many form factors through adverse conditions (voice, data and now satellite), and has a slew of safety features (crash detection).

Garmin has decades of experience regarding outdoor travel and safety that Apple would always be playing catchup...IMO.

They got around the antenna issue by using a really poor antenna that requires the user to aim the phone at a passing satellite, plus a pretty cool UI to help you do that.

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