Hi list, Like a great many people, i can afford consumer GPS units (~$100) but not a 'professional' unit (~$4000-8000). Of course, the well-known lack of accuracy in consumer units (~10m) is nowhere near usable for many applications.
The solution that springs to mind would be a cheap differential: 1. Buy a second consumer GPS unit. 2. Tie it to a post or other fixed object. 3. Walk around, gathering data with the first GPS. 4. Download data from both units. 5. Using the timecode to correlate, subtract the second unit's drift from the first unit's coordinates. >From everything i've read, it seems to me that would bring the 5-10m error >down to 1-2m. However, i didn't find any software to do this simple operation. There is plenty of information out there about fancier DGPS using WAAS or other things which are not widespread and/or not reliable (http://www.gpsinformation.org/dale/dgps.htm) There is high-end proprietary software like GrafNav (http://www.novatel.com/products/waypoint_grafnav.htm) which apparently costs thousands of dollars. But it should be a really simple operation to subtract one track's offset from another. Is there some reason this simple approach wouldn't work? Is there some FOSS which will do it? Thanks, Ben http://vterrain.org/ _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking
