# Talk:GPS accuracy

Wow, I didn't know all that. Fortunately I have one decimal point of seconds -- so three metre precision -- and usually get 3 m accuracy displayed, so that by these methods I've been within 3 m all along. Thanks. -Robyn 21:46, 4 May 2009 (UTC)

Are you going to define degree minute and second? -Robyn 23:40, 4 May 2009 (UTC)

It's kind of a big task. Don't forget compass bearings and the cold geohash achievement, even ignoring educational levels and the meetup graph. If it were me, I'd delete the squere brackets and step away from the can of worms, keeping my hands in sight. -Robyn 23:40, 4 May 2009 (UTC)

## [edit] Ummm, I think there's an error

To quote:

"A simple rule of thumb is to add together the possible errors in precision and accuracy, and halve the total. This will give you the radius of a circle, centred on you, within which your destination lies....

"For example, if your GPSr uses four decimal digits of degrees, and is quoting a signal accuracy of 5 metres, the simple rule of thumb gives an error circle of radius 10.5-metres."

Actually, since the precision of .0001 gives 11 meters, and the accuracy is 5 meters, then (11+5)/2=8 meters. 11/2+5=10.5 meters. The example for the second method has the same flaw. So, it looks to me like there's an arithmetic error.

Unless, of course, the intent all along was to halve the precision (expressed in meters) and then add the accuracy. But the way it's written, it's the average of the accuracy and the precision that's desired. Basil (talk) 23:24, 4 November 2013 (EST)