[pct-l] Gps (patrick white )

[Gary Wright]

On Nov 15, 2011, at 2:26 PM, Jim & Jane Moody wrote:
> One caveat with a gps app on a smartphone - if your phone only receives its signal from cell towers, and if you're somewhere with no cell service, you also are without gps capability . 


By definition you can't have a GPS app on a phone that doesn't have a GPS radio (i.e. location via cell towers only).  That being said I don't think there are many (if any) smartphones on the market today that don't have a GPS radio.  The newest phones (e.g. iPhone 4S) actually have dual GPS and GLONASS radios.  GPS is the US network of satellites.  GLONASS is the Russian system.

Most smart phones utilize both cell tower and GPS signals to determine location. This is often called AGPS (assisted GPS).  The combined system determines a location faster than a GPS-only system.

Radar