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iPhone 14 Pro comes with dual-frequency GPS

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Re: iPhone 14 Pro comes with dual-frequency GPS

#51

Post by matt_attack »

pxeboot wrote: post #41
ghaff wrote: post #22

Earlier quoted context omitted.

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.

Well most offline devices don't take minutes now except for the first fix in a long time. It's generally around 30 seconds to a minute.

Usually the almanac is stored in non-volatile memory so additional startup fixes are much faster.

Re: iPhone 14 Pro comes with dual-frequency GPS

#52

Post by MilaM »

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.

How is the positioning accuracy outdoors?

My iPhone 13 is rather disappointing in this regard. Even in my garden, with a clear sky, Maps.app will show my location at least 5 m off my actual position.

Re: iPhone 14 Pro comes with dual-frequency GPS

#54

Post by m3kw9 »

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)

Android has copy and paste before iOS but you wouldn’t want to brag about it just because. It didn’t work well at all till iOS came out with their implementation

Re: iPhone 14 Pro comes with dual-frequency GPS

#55

Post by Rebelgecko »

oneplane wrote: post #50
ashirviskas wrote: post #43

Earlier quoted context omitted.

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.

You don't need every satellite to be broadcasting the L5 signal to benefit. In fact there's probably diminishing returns, you really only need to receive one L5 signal to do ionosphere correction

Re: iPhone 14 Pro comes with dual-frequency GPS

#56

Post by tomcam »

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…

That was infinitely better than TFA, thanks.

Re: iPhone 14 Pro comes with dual-frequency GPS

#57

Post by labcomputer »

Rebelgecko wrote: post #55
oneplane wrote: post #50

Earlier quoted context omitted.

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.

You don't need every satellite to be broadcasting the L5 signal to benefit. In fact there's probably diminishing returns, you really only need to receive one L5 signal to do ionosphere correction

Ha, if only. No, a satellite broadcasting L5 only gives you ionospheric corrections for that satellite.

Otherwise what would be the point? WAAS already gives ionospheric corrections for a course grid. If you could just assume that the ionospheric delay was constant across the sky, you wouldn’t need L5 at all.

Re: iPhone 14 Pro comes with dual-frequency GPS

#58

Post by oneplane »

Rebelgecko wrote: post #55
oneplane wrote: post #50

Earlier quoted context omitted.

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.

You don't need every satellite to be broadcasting the L5 signal to benefit. In fact there's probably diminishing returns, you really only need to receive one L5 signal to do ionosphere correction

It doesn't matter how little you need if there are big gaps in availability. Granted, having prepared hardware and sometimes-coverage is great, but the buck has got to stop somewhere.

Re: iPhone 14 Pro comes with dual-frequency GPS

#59

Post by Waterluvian »

banana_giraffe wrote: post #45
Waterluvian wrote: post #39

Earlier quoted context omitted.

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.

Thanks! Indeed, it seems logical that they’re shipping the same tech inside these same gen devices. I think Apple has been very consistent with that (except for when they intentionally ship older tech like in the SE)

Re: iPhone 14 Pro comes with dual-frequency GPS

#60

Post by dylan604 »

anotherOneSound wrote: post #18
toomuchtodo wrote: post #14

Earlier quoted context omitted.

Are there any specific use cases where this will see outside benefit (urban areas)? Or is it just faster fix and higher precision without PPS/RTK?

inside of the mall when your weather widget pulls your location every 5 minutes they will better know what stores you went in to in what order

Wouldn't the WiFi and Bluetooth beacons provide more accurate and more granular points of data than polling GPS for this purpose?
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