My Go 720 is not accurate

[Coastie]

...but we don't need any newbies scanning through this thread and thinking that the "address locations" are "bad" in TomTom units, either...

that would be me, still trying to decide on which brand to buy

 

[The Spook]

Hi Chantillace,

I think the most important thing to realise is that a postal address, unlike a coordinate, is not a precise spatial location. It is only a guideline (for the postman) to the location, hence it is not entirely accurate when used for navigation. It is also never going to be.

Briand (who obviously does know a thing or two about GIS ) made this point saying:

There is no GPS Coordinate <--> Physical Address mapping.

Even if there was such a database it would quickly become inaccurate as addresses change. Coordinates don't.

Imagine that I have a farm with 2 miles of road frontage. My address may be: "Old Farm, 2567 Country Road, Wherever". Perhaps a mapping company will record the exact location of my farm (though most likely not). What if I knock down my 'old farm' and build a new one further along the road on my land? My postal address would be unchanged, even though I have relocated my house nearly 2 miles down the road. Of course, the postman will still find me, but your sat-nav doesn't have a chance.

A good way to see if your device is accurate is to do what is mentioned buy Lec510:

...in front of your home with the GPS, let it acquire full signal, set your Home as current GPS position, drive away away a few blocks then Navigate Home.

I think you will find that your TomTom gets you to the exact location.

Hence, the problem is with postal addresses, not GPS. It is not something that is fixable. If you want to get to a precise location, you have to use coordinates. Otherwise, you will only get it's approximate location. That may be good enough, but it may not.

Apologies for the sarcastic tone in may last post.



*post edited for grammar!