On pre-GPS roms, does 911 GPS *REALLY* work?

[Novicaine]

I'm curious... on the pre-GPS roms, supposedly the GPS works when you call 911... somehow I doubt it. If it takes effort (installing programs to download satellite locations, running programs to init the GPS) with anything less than the latest roms even to make the GPS get a lock in less than 15 minutes, then how does it happen to work when you're trapped under your burning car in the middle of a cornfield and dial 911 with your one free hand?
Just curious...

[rhannahs19]

to my knowledge all phones made in the past recent years have a E911 gps chip built in that i BELIEVE is seperate from the regular gps chip. the e911 gps chip is designed to give police and rescue squads your location within about 30 seconds... does it work? i sure hope so..

[Spr0ckEt]

I do dispatch for the local county and I can tell you that it DOES work. On all cell phones (just about) that make calls to 911. We get a little google maps-type picture with a circle around you (within about 30yards). The one thing that I haven't seen ours follow someone on the highway. Usually it just pinpoints the initial location.

[apacho01]

There is a nice little article on how it works here

[apacho01]

OK here is a better one from How Stuff Works

[weedahoe]

My GFs sis works dispatch and they can track you almost instantly. There are no Pre-GPS ROMS as all phones are GPS compliant since early 2k. No carrier will even activate a non-GPS compliant phone now.

[arparent]

E911 GPS is not really GPS. It triangulates your approximate location based on cellular tower signals. It isn't useful for anything moving... like say, navigating while driving.

[gbm85]

Originally Posted by arparent

E911 GPS is not really GPS. It triangulates your approximate location based on cellular tower signals. It isn't useful for anything moving... like say, navigating while driving.

NOT TRUE at all!

Sprint, Verizon, and Alltel all use aGPS which is actually better than stand-alone GPS in many cases. The aGPS gets an estimated position via data from the cell tower, then uses that to get a super-fast lock on satellites (since the phone already knows pretty much where it is, the initial lock doesn't take so long).

I guess if Spr0ckEt is right, it kinda sucks that it can't track you if you start moving, but an initial location is better than no location.

http://en.wikipedia.org/wiki/E911#Wireless_Enhanced_911

[weedahoe]

Originally Posted by gbm85

NOT TRUE at all!

Sprint, Verizon, and Alltel all use aGPS which is actually better than stand-alone GPS in many cases. The aGPS gets an estimated position via data from the cell tower, then uses that to get a super-fast lock on satellites (since the phone already knows pretty much where it is, the initial lock doesn't take so long).

I guess if Spr0ckEt is right, it kinda sucks that it can't track you if you start moving, but an initial location is better than no location.

http://en.wikipedia.org/wiki/E911#Wireless_Enhanced_911

First of all, go back and read where he said "e"GPS. Not "a"GPS. Secondly, aGPS will never be better that stand-alone GPS. You need to go back to GPS school for GPS v/s aGPS and look at triangulation v/s transponders and how many you need and how close they can pin point your location of within feet v/s yards.

[arparent]

Agreed, I was referring to 'normal' cellular phones. Not phones with actual GPS in them.

Originally Posted by weedahoe

First of all, go back and read where he said "e"GPS. Not "a"GPS. Secondly, aGPS will never be better that stand-alone GPS. You need to go back to GPS school for GPS v/s aGPS and look at triangulation v/s transponders and how many you need and how close they can pin point your location of within feet v/s yards.