6 ms·

"Nobody uses"... Do you understand what you just said? Raw GPS is universally unusable, requiring up to half an hour of waving your phone under clear sky, hopi

by pona-a 3y ago

"Nobody uses"... Do you understand what you just said? Raw GPS is universally unusable, requiring up to half an hour of waving your phone under clear sky, hoping it a) will actually work; b) will not loose signal; c) will not drain the battery before you reach your destination. The only way to get reasonable estimation of location? Location services. Guess who are the only providers? About 5 or something companies, all with expensive licenses and weird terms of use. And here comes Mozilla, providing this same expensive exclusive service for free as a convenient API. Just send some WiFi SSIDs and signal strength, cell towers, and Bluetooth devices, and without even having to turn on the actual GPS, you get a faster, more accurate estimate of geolocation, down to a few meters. This service is vital to mobile Linux or even deGoogled Android or non-Chrome browsers. In its time Canonical had to plead with Here maps for years to give their devices proper GPS. To say a project unique in its entire domain on which hinges the existence of entire ecosystems is less important than a yet VPN or email alias service seems downright silly. Besides, it's not like Mozilla did it on their own volition. A patent troll had come to destroy their competitor on shaky legal footing, knowing they won't fight back...

traceroute66 3y ago
> Raw GPS is universally unusable, requiring up to half an hour of waving your phone under clear sky, Sigh. The increasing amount of unsubstantiated FUD finding its way on to HN recently is depressing. Two glaringly obvious points to make at your nonsense: 1. What you describe is ancient history. It applied to old previous-generation devices with single-frequency chipsets (L1 GPS signals). However, effectively 100% of devices released within the last 3–5 years (and more in the case of certain manufacturers !) (a) have L1,L2,L5 GPS chipsets and (b) have multi-frequency GPS chipsets whch work not only with the "original" GPS but also Galileo, QZSS and others. 2. Even if we accept your argument, which we should not, then the rapid adoption of Apple's FindMy network (and the equivalent for Google) surely cannot have escaped your attention ? These serve to increase accuracy. The reality is there is fast becoming no need for a third-party service such as the one Mozilla provided, because there is now first-class support for sufficiently robust high-accuracy positioning.
- stavros 3y ago
  This is correct. I use GPS in RC planes and only the initial sync is that slow (when it has to download the ephemerides). Subsequent boots/syncs only take a few seconds, and you obviously get great resolution with just the GPS unit.
  - tonyarkles 3y ago
    I'm assuming you're using a UBlox M8 or F9P or something similar? Most of the built units have a small battery or supercap that allows them to retain almanac and ephemeris data while powered off. If the ephemeris data is less than 4 hours old this will allow it to very quickly re-sync to the visible SVs and get a lock again. It's quite impressive, though, at how the hardware has improved. For a complete cold start one of the challenging issues is to actually find a single satellite to listen to. For GPS there's 32 different spreading codes and each transmitted signal is affected by Doppler shift depending on its position and velocity relative to where you are on the Earth. You basically have to iterate through (spreading code, Doppler shift) pairs and run a correlator to see if there's a signal present. Contemporary hardware has a ton of correlators that can run in parallel which can significantly improve the TTFF (time to first fix). As soon as you find one SV and start to get a bit of almanac data you can quickly eliminate (spreading, Doppler) options from the problem space by dropping SVs that you know are not going to be visible.
    - stavros 3y ago
      Yep, exactly. And a mobile phone has an internet connection, which means that it always has an up-to-date ephemeris.
- sham1 3y ago
  I use the Mozilla location services to have my Linux desktops and laptops automatically figure out where they are in order to properly apply blue-light filtering at night. How might one be able to integrate either the aforementioned Apple or Google services into the system to provide the appropriate location data? Or would it instead require the purchase of separate GPS units for these computers in order to have them know just where they are? Dismissal of Mozilla being forced to bring down an essential service like this because the concerned post has some FUD in it, and that proprietary alternatives exist so what's the worry, is frankly disgusting. Especially when it's done via the blatantly immortal (but technically legal!) abuse of the legal system like this.
overstay8930 3y ago
What year did you last use GPS, it’s even usable deep within cities now. Modern devices use GPS, GLONASS, GALILEO, and various regional ones too. Locking on is super fast and it’s hard to lose unless you walk inside of a big building. I can even get a good GPS lock inside my house, it’s really good these days. You’re right that it can use more power, but it’s really not that bad with modern hardware.
- jeroenhd 3y ago
  With an up to date AGPS database, GPS is quite usable. AGPS is also distributed as a service, though, often by companies that made the GPS receiver chips. If that were to fall away, you'd struggle to make GPS usable for phones. You may not need Google for a GPS lock, but you certainly can't get a good fix without an external party. I've unwittingly tried this, when I saw a weird HTTP URL on my network being polled in the background; I blocked it in my Pihole and found out not much later that my phone's GPS started taking longer and longer to get a fix. Not "waving your phone 30 minutes at a clear sky" long, but definitely to the point where using Google Maps with cell/WiFi scanning disabled become very annoying.
  - dgacmu 3y ago
    I run a modest fleet of mostly-offline data collection devices that rely on GPS; we pay a lot of attention to how long it takes before they can sync. With a good sky view, the GPS chip often has a 3D position lock before Linux has finished booting. What you're seeing is the effect of AGPS and the interaction with the phone's aggressive power management. https://en.m.wikipedia.org/wiki/Assisted_GNSS https://en.m.wikipedia.org/wiki/Assisted_GNSS It's not really a limitation of GPS, it's about using the external service to let you minimize the time your GPS receiver is active. You can get a great fix without AGPS, but you can't both keep the GPS off 99.9% of the time _and_ get a fast, great position fix.
    - jeroenhd 3y ago
      Fair enough, I suppose. I think in the context of smartphones, continuously operating the GPS chip is simply not an option, but in other types of devices that isn't as big of a problem.
deleted 3y ago
[deleted]
ianburrell 3y ago
AGPS provided by the mobile carriers is sufficient. It is downloading the ephemeris that is slow, not getting the fix. That isn't considered Location Services. You could test this by disabling WiFi, downloading AGPS from mobile, and then driving to place without service or putting in airplane mode. GPS fix will be fast cause ephemeris is good for days and corrections are small.

by pona-a 3y ago

traceroute66 3y ago

> Raw GPS is universally unusable, requiring up to half an hour of waving your phone under clear sky, Sigh. The increasing amount of unsubstantiated FUD finding its way on to HN recently is depressing. Two glaringly obvious points to make at your nonsense: 1. What you describe is ancient history. It applied to old previous-generation devices with single-frequency chipsets (L1 GPS signals). However, effectively 100% of devices released within the last 3–5 years (and more in the case of certain manufacturers !) (a) have L1,L2,L5 GPS chipsets and (b) have multi-frequency GPS chipsets whch work not only with the "original" GPS but also Galileo, QZSS and others. 2. Even if we accept your argument, which we should not, then the rapid adoption of Apple's FindMy network (and the equivalent for Google) surely cannot have escaped your attention ? These serve to increase accuracy. The reality is there is fast becoming no need for a third-party service such as the one Mozilla provided, because there is now first-class support for sufficiently robust high-accuracy positioning.

stavros 3y ago
This is correct. I use GPS in RC planes and only the initial sync is that slow (when it has to download the ephemerides). Subsequent boots/syncs only take a few seconds, and you obviously get great resolution with just the GPS unit.
- tonyarkles 3y ago
  I'm assuming you're using a UBlox M8 or F9P or something similar? Most of the built units have a small battery or supercap that allows them to retain almanac and ephemeris data while powered off. If the ephemeris data is less than 4 hours old this will allow it to very quickly re-sync to the visible SVs and get a lock again. It's quite impressive, though, at how the hardware has improved. For a complete cold start one of the challenging issues is to actually find a single satellite to listen to. For GPS there's 32 different spreading codes and each transmitted signal is affected by Doppler shift depending on its position and velocity relative to where you are on the Earth. You basically have to iterate through (spreading code, Doppler shift) pairs and run a correlator to see if there's a signal present. Contemporary hardware has a ton of correlators that can run in parallel which can significantly improve the TTFF (time to first fix). As soon as you find one SV and start to get a bit of almanac data you can quickly eliminate (spreading, Doppler) options from the problem space by dropping SVs that you know are not going to be visible.
  - stavros 3y ago
    Yep, exactly. And a mobile phone has an internet connection, which means that it always has an up-to-date ephemeris.
sham1 3y ago
I use the Mozilla location services to have my Linux desktops and laptops automatically figure out where they are in order to properly apply blue-light filtering at night. How might one be able to integrate either the aforementioned Apple or Google services into the system to provide the appropriate location data? Or would it instead require the purchase of separate GPS units for these computers in order to have them know just where they are? Dismissal of Mozilla being forced to bring down an essential service like this because the concerned post has some FUD in it, and that proprietary alternatives exist so what's the worry, is frankly disgusting. Especially when it's done via the blatantly immortal (but technically legal!) abuse of the legal system like this.

overstay8930 3y ago

What year did you last use GPS, it’s even usable deep within cities now. Modern devices use GPS, GLONASS, GALILEO, and various regional ones too. Locking on is super fast and it’s hard to lose unless you walk inside of a big building. I can even get a good GPS lock inside my house, it’s really good these days. You’re right that it can use more power, but it’s really not that bad with modern hardware.

jeroenhd 3y ago
With an up to date AGPS database, GPS is quite usable. AGPS is also distributed as a service, though, often by companies that made the GPS receiver chips. If that were to fall away, you'd struggle to make GPS usable for phones. You may not need Google for a GPS lock, but you certainly can't get a good fix without an external party. I've unwittingly tried this, when I saw a weird HTTP URL on my network being polled in the background; I blocked it in my Pihole and found out not much later that my phone's GPS started taking longer and longer to get a fix. Not "waving your phone 30 minutes at a clear sky" long, but definitely to the point where using Google Maps with cell/WiFi scanning disabled become very annoying.
- dgacmu 3y ago
  I run a modest fleet of mostly-offline data collection devices that rely on GPS; we pay a lot of attention to how long it takes before they can sync. With a good sky view, the GPS chip often has a 3D position lock before Linux has finished booting. What you're seeing is the effect of AGPS and the interaction with the phone's aggressive power management. https://en.m.wikipedia.org/wiki/Assisted_GNSS https://en.m.wikipedia.org/wiki/Assisted_GNSS It's not really a limitation of GPS, it's about using the external service to let you minimize the time your GPS receiver is active. You can get a great fix without AGPS, but you can't both keep the GPS off 99.9% of the time _and_ get a fast, great position fix.
  - jeroenhd 3y ago
    Fair enough, I suppose. I think in the context of smartphones, continuously operating the GPS chip is simply not an option, but in other types of devices that isn't as big of a problem.

deleted 3y ago

[deleted]

ianburrell 3y ago

AGPS provided by the mobile carriers is sufficient. It is downloading the ephemeris that is slow, not getting the fix. That isn't considered Location Services. You could test this by disabling WiFi, downloading AGPS from mobile, and then driving to place without service or putting in airplane mode. GPS fix will be fast cause ephemeris is good for days and corrections are small.