GPS Grid for Walking in Australia
Q. I have a basic Garmin etrex. Which grid systen can I use for walking in Australia?
Peter Robinson, Liverpool
A. The trite answer is that you can use any grid you want to. The important thing is to use the same grid as the map that you are working from. If you are working from Google, Yahoo or Open Street Map then use WGS84; most paper maps will have the datum on which it is based printed on the map. The Australian 1966 and 1984 datums are almost identical (but some way from WGS84); the 1994 datum is as close to WGS84 as makes no difference.
John Thorn, Cardiff