GPS Map comparison

Hi Doug,
interesting comparisons. I always look at various maps and compare them when preparing a journey. I also compare my actual track travelled on the journey, against the maps as well. It is amazing the differences I have found, especially in Arnhem Land. There is often many kms difference between the actual track travelled and that shown on the map, often due to tracks being damaged by floods and re-routed to higher or firmer ground. Same goes in central australia.

But your example above, shouldn't in fact occur.

Hmmm - I note the same, and a question is: are all the various map overlays using the same map datum? e.g. WGS84 - and later versions to take into account GPS data - i.e. "WGS 84 (G873)", adopted I think in 1997.

Now one would think that between 1997 and 2009 would give enough time for mapping authorities and organisations to streamline their map data, but I think in Australia's case, the huge size of the country and lack of resources mean that we have some dud information, add to that old survey data that has not been updated with modern equipment.

Travelling through Europe I note stark contrasts between various country's data - France, excellent, Germany excellent, Holland, Denmark, also excellent. Norway, fair, Austria - amazingly accurate (as you would expect). Now Italy....... good in some parts, woeful in others. And Australia, outside the cities, is last.

Old story of GIGO - Garbage In, Garbage Out.

I am looking for some software for outback work to upload to my Garmin (in my travels a revered and precious little bit of electronic usefulness) - I have OzTopo V2 (V3 coming out.... when???) - am looking at the Garmin Topo product - how do you find it when compared to the others mentioned?

viz

This is the same area taken from Magellans DiscoverAus Streets and Tracks.
Looks very similar to your OzTopo V2

Image Could Not Be Found

Chris

Gday Doug,
Cd is the way to go, you can load it to a decent sized SD Card. I bought the Garmin Topo on Sd card and it does have some shortcomings. It comes on a 2 gig micro SD and it takes up 1.78 gb, so it has no room to add music and other items. You cannot transfer the file to another bigger sd card, the lock does not work when you move the file to another card. It really is just a plug and play with little foresight for other applications on most Nuvi's!! I also found the contour lines are very pronounced and in hilly country where there is a lot of them, they are a bit overbearing. It would be nice of garmin to provide a second mapset with all the ground detail without the contours. Michael

Excellent info there Doug.

When you put Garmin Topo into your new Nuvi, do you have to swap SD cards or can Garmin Topo co-exist with the normal Nuvi maps?