Hi.
I have a big project land on my desk using GPS in conjunction with RFID to measure every pickup of every bin in a Local Government Authority area. That's about 150,000 bins.
I tried to search this forum but I'm not turning up much on GPS - so please feel free to reply with links to older messages.
The information I'm after is:
1. What's the best equation to calculate point to point distance between two sets of longitude and latitude co-ordinates? It needs to be accurate to about 0.5 m (when the points are accurately known).
What I've done so far is to use the "Great Circle Distance" - estimating the radius of the earth between the two points based on a Radius at a given geodetic latitude
(http://en.wikipedia.org/wiki/Earth_radius) Is there a better calculation, or will that suffice?
2. What's the normal variance on GPS devices?
3. Can someone give a quick run down on the process of Differential GPS, and how I might implement it. I have a couple of dozen trucks that collect data from known locations - approximately 10,000-20,000 reads per day for all trucks.
My thought is that any distortions could be detected and accounted for by using all trucks data. This would increase the accuracy of the GPS reads.
The reason an increased accuracy is advantagous is when we have an unexpected scan of an RFID (bin). This means that either the bin is stolen,
misplaced or otherwise "away" from where it is meant to be. Also, when we "FAIL" to read the RFID (but we do read the GPS), it would be good to find the actual house accurately.
Thanks,
Philip
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