Re: [ILUG-BOM] Open Street Mapping Questions

On 28-Jun-08, at 11:37 AM, jtd wrote:

Also by fixing two points accurately on the periphery by non gps means,

how is this done? I am told that in America there are markers everywhere giving reference points. The only one in India I have seen is at St Thomas Mount where they started the survey of India.

you could get a deviation figure and correct your readings. You will have to take the correction every few hrs as ionospheric delays vary with sun activity.

I tried marking the main fountain in Ooty - walked around it 3 times and marked the waypoints. They were all over the place. I was using a garmin device and it was showing accuracy of 30-35 metres on that day.