> The equipment I'm currently working on is capable of an accuracy > somewhat better than 10cm with correction or about 30cm without. Quite > fun to play with. A friend noted: "RP should take a look at the Leica GPS surveying gear - they are quoting sub-mm rms resolutions and accuracies based on differential techniques.." Russell --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .