Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

iPhone 14 Pro comes with dual-frequency GPS

apple.com

Post reply on HN
Print view View original

41–50 of 205 posts

Re: iPhone 14 Pro comes with dual-frequency GPS

#41

Post by pxeboot »

ghaff wrote: post #22
simonjgreen wrote: post #12

Earlier quoted context omitted.

I for one absolutely recall "classic" GNSS based purely on GPS. The combination of only having GPS, early slow hardware with only cold starts, young software implementations, made for quite a ropey experience. I think my first proper experience was a PCMCIA GPS card in an HP IPaq running TomTom 2, or possibly some Garmin version. Revolutionary at the time, and brilliant on long journeys, but compared to today it was…

I still have an old Garmin for sea kayaking that I sometimes use. With a completely clear view of the sky it can easily take quite a few minutes to get a fix.

This is actually how all gps devices still work, including the latest smartphones and watches. It's just that now, devices can pre-download the almanac over your data connection, mostly eliminating that delay.

Re: iPhone 14 Pro comes with dual-frequency GPS

#43

Post by ashirviskas »

cesarb wrote: post #29

For Android users, there's an interesting article about dual-frequency GPS at https://barbeau.medium.com/dual-frequency-gnss-on-android-de... (source: https://github.com/barbeau/gpstest/blob/master/FAQ.md#does-g... ).

So my 2 year old Android device already had a feature that was only now implemented by Apple in their top of the line products. Neat.

Does anyone have personal experience of how dual-frequency improves GPS? As I'm not really using GPS a lot, I'm not sure I noticed a difference from my previous devices (I live in EU, so also no high rise skyscrapers here)

Re: iPhone 14 Pro comes with dual-frequency GPS

#44

Post by jtolmar »

Forge36 wrote: post #2

For those of us not deep into the technical details here: what's this mean?

GPS assumes* light travels in a straight line, which it doesn't due to atmospheric effects and reflections off buildings. L5 is a second frequency from the same satellites, which is affected by these problems differently, so the chip can compare the differences between the two signals and guess what's up with the atmosphere and buildings / throw out the dumber looking signal. It's also mostly independent so it's more data. L5 is also a bit less affected by atmosphere inherently.

The upshot is much better accuracy in urban canyons, and a small improvement where GPS was already good.

* Obviously people making chips and apps know this and try to mitigate it.

Re: iPhone 14 Pro comes with dual-frequency GPS

#45

Post by banana_giraffe »

Waterluvian wrote: post #39
elfchief wrote: post #34

Earlier quoted context omitted.

Neat, if so! Where do you see that, though?

Apologies for lack of a better source. A slide during the live presentation mentioned this. I’d estimate a 10% chance I’m misremembering.

Pretty big slide at 0:29:28 into the event:

https://imgur.com/a/mSZ17Fv

That said, this was talking about the Apple Watch Ultra. I'd assume it's the same for the phone, but I don't have proof of that.

Re: iPhone 14 Pro comes with dual-frequency GPS

#46

Post by chanandler_bong »

jtolmar wrote: post #44
Forge36 wrote: post #2

For those of us not deep into the technical details here: what's this mean?

GPS assumes* light travels in a straight line, which it doesn't due to atmospheric effects and reflections off buildings. L5 is a second frequency from the same satellites, which is affected by these problems differently, so the chip can compare the differences between the two signals and guess what's up with the atmosphere and buildings / throw out the dumber looking signal. It's also mostly independent so it's more…

Great, simple answer. Thank you!

Re: iPhone 14 Pro comes with dual-frequency GPS

#47

Post by snovv_crash »

antegamisou wrote: post #8
Forge36 wrote: post #2

For those of us not deep into the technical details here: what's this mean?

Dual frequency mitigates the ionospheric delay error of GPS signals, yielding more accurate measurements.

This. Adding a second channel means that without RTK/PPK you can get ~30cm precision. The rest is just technical details.

Re: iPhone 14 Pro comes with dual-frequency GPS

#48

Post by snovv_crash »

makeitdouble wrote: post #38
aaaaaaaaaaab wrote: post #30

Earlier quoted context omitted.

GPS is passive.

I don’t share parent’s pessimism, but I think that comment was probably referring to tracking inside apps and having better tracking accuracy. Basically Pokemon Go would know you went to the burger shop and not the Hawaian pancake shop 50m before.

Dual band (30cm accuracy) would mean that they know that you weren't walking on the sidewalk during pokemon go and could report you for jwalking.

Re: iPhone 14 Pro comes with dual-frequency GPS

#49

Post by oneplane »

shaky-carrousel wrote: post #21
NelsonMinar wrote: post #3

Article about what dual-frequency GPS is: https://www.zdnet.com/article/what-is-l5-precision-dual-freq... It says that GPS has added a new band (L5) that works better indoors. Combining it with traditional L1 gives better results. L5 is not fully deployed.

My Google Pixel 6 can already do this. I can see L5 and L1 GPS satellites at the same time right now. I can also see a lot of other systems ones.

I'm sure once L5 has an actual complete deployment it will be used by even more devices.

Re: iPhone 14 Pro comes with dual-frequency GPS

#50

Post by oneplane »

ashirviskas wrote: post #43
cesarb wrote: post #29

For Android users, there's an interesting article about dual-frequency GPS at https://barbeau.medium.com/dual-frequency-gnss-on-android-de... (source: https://github.com/barbeau/gpstest/blob/master/FAQ.md#does-g... ).

So my 2 year old Android device already had a feature that was only now implemented by Apple in their top of the line products. Neat. Does anyone have personal experience of how dual-frequency improves GPS? As I'm not really using GPS a lot, I'm not sure I noticed a difference from my previous devices (I live in EU, so also no high rise skyscrapers here)

I doesn't matter if your device had it for 99999 years and is therefore 'way cooler', what matters is how far along the GPS satellites are, and at this stage there isn't even one complete deployment, it's still being deployed.
Post reply on HN