GPS Enhancer Setting

[daveoftruro]

I have just discovered the GPS Enhancer On/Off switch in Settings - Advanced, and I'm trying to find out what it does.

With the switch already set to the ON position, I went to Browse Map and it showed my location as that of the local cellphone transmitter site, about half a mile away (I was inside my house at the time,).

I switched OFF the GPS Enhancer, went back to Browse maps and my position had now changed to a spot 10 yards away (ie the switch did the opposite of what it says on the label!). Presumably it had got this from the address of my WiFi server.

Reversing it again, (and again) and it gave up trying, simply saying it could not find my position. Did I want to use last known etc

I have seen a s/w 1.5 release note (but can't find it now) which says that when GPS is not available, it will use cellphone sites and Wifi to determine its position. It looks like it's doing this with GPS Enhancement Off, but not when it's On. Strange!

Any suggestions as to what GPS ENhancement is actually doing?

 

[SeniorShizzle]

GPS Enhancer

As I understand it, GPS Enhancer only compensates for GPS performance while moving, not while standing still. While standing still, WiFi positioning is not very accurate, as it simply takes the approximate location of the base station and uses a mathematical formula to calculate a radius based on the received WiFi signal. Thus, you are only placed at some location on the edge of a circle (say, at the 6 o'clock position), and you could be positioned several hundred feet away from your actual location (say, the 2 o'clock position). This is also combined with the fact that GPS location is always more accurate when calculating the position of a moving object, as the time data received from the GPS satellites can be calculated with a differential from the previous location, as opposed to calculating the same data constantly.

This may not be the TomTom app, but I know some methods of GPS compensation use the accelerometer to calculate forward acceleration, which is mathematically combined with the GPS and other location data to give a more precise and accurate measurement of GPS data.

 

[gatorguy]

Nice answer.

 

[Liquid Rhino]

When using a Car Kit with built-in GPS receiver such as the TomTom or Magellan cradles, should this option remain on (as is by default) or should it be switched off? Can't seem to find any real documentation on this

I did briefly set it to off on while on a route but didn't really notice any lag or choppiness enough to warrant either setting, just curious as to the optimal choice or other user's experiences.

 

[KS8]

Bringing this question back as I too was wondering about the same. Any one now know the answer to the last question? Thanks