4 ms·

An in-car unit is permanently powered and can maintain a warm-fix for much faster positioning than a cold-fix from my phone, which takes about five minutes with

An in-car unit is permanently powered and can maintain a warm-fix for much faster positioning than a cold-fix from my phone, which takes about five minutes with a good view. Plus the advantages of a large, external antenna. Instead of holding my phone out of the sunroof...

mi100hael 9y ago
What phone do you have that could possibly require 5 mins and an arm out the sunroof just for a GPS fix?
- Symbiote 9y ago
  Many phones with data service switched off, which might be the case when driving abroad.
  - Bud 9y ago
    Data service has nothing to do with a GPS fix. Nothing at all. No data is used. GPS does not require any internet connection at all.
    - ropiku 9y ago
      You are technically true but if you don't have internet connection to get the almanac (future position of satellites) you have to wait 12.5 minutes to download it very slowly from the GPS itself. That's what parent was saying. It works but the time-to-fix is very high.
    - mynewtb 9y ago
      AGPS uses data service to get the almanac.
      - Bud 9y ago
        Thank you. I learned something from this. How often does that almanac need to be updated, however?
- Rebelgecko 9y ago
  Time to fix can be worse if you've moved since your last fix, or if you're moving quickly. If you don't have a network connection to download the almanac info, it takes 12.5 minutes to receive in its entirety.
ebikelaw 9y ago
These things are also true of Android Auto. It uses the GPS equipment in your car. I leave a dedicated phone in my car's glove box and it always has a strong location. Android Auto also has access to the car's wheel speed and steering angle sensors so it can use dead reckoning when underground. GPS units can't do that.
- netsharc 9y ago
  > Android Auto also has access to the car's wheel speed and steering angle sensors Hah, that's pretty interesting. To make a flippant joke, imagine if Facebook had this info, "Hey $AUTO_INSURER, 30% of people who visit your portal and log into it (we have this info because you added a 'Like our page on Facebook' iframe in the page) are bad drivers, you want to know who they are? Pay us and we'll tell you!".

mi100hael 9y ago

What phone do you have that could possibly require 5 mins and an arm out the sunroof just for a GPS fix?

Symbiote 9y ago
Many phones with data service switched off, which might be the case when driving abroad.
- Bud 9y ago
  Data service has nothing to do with a GPS fix. Nothing at all. No data is used. GPS does not require any internet connection at all.
  - ropiku 9y ago
    You are technically true but if you don't have internet connection to get the almanac (future position of satellites) you have to wait 12.5 minutes to download it very slowly from the GPS itself. That's what parent was saying. It works but the time-to-fix is very high.
  - mynewtb 9y ago
    AGPS uses data service to get the almanac.
    - Bud 9y ago
      Thank you. I learned something from this. How often does that almanac need to be updated, however?
Rebelgecko 9y ago
Time to fix can be worse if you've moved since your last fix, or if you're moving quickly. If you don't have a network connection to download the almanac info, it takes 12.5 minutes to receive in its entirety.

ebikelaw 9y ago

These things are also true of Android Auto. It uses the GPS equipment in your car. I leave a dedicated phone in my car's glove box and it always has a strong location. Android Auto also has access to the car's wheel speed and steering angle sensors so it can use dead reckoning when underground. GPS units can't do that.

netsharc 9y ago
> Android Auto also has access to the car's wheel speed and steering angle sensors Hah, that's pretty interesting. To make a flippant joke, imagine if Facebook had this info, "Hey $AUTO_INSURER, 30% of people who visit your portal and log into it (we have this info because you added a 'Like our page on Facebook' iframe in the page) are bad drivers, you want to know who they are? Pay us and we'll tell you!".