Comment on GPS signals are surprisingly easy to disruptparentComments−VLM13yThis is optical:http://www.topconpositioning.com/products/total-stations/con..."can measure in reflectorless mode up to 500m at an incredible 3mm + 2ppm accuracy."A typical GPS:http://www.topconpositioning.com/products/gps/modular-soluti...Static H: 3mm +0.5ppm (x baseline length) V: 4mm +1.0ppm (x baseline length)So GPS gives you lower PPM than optical for long runs but lower accuracy on short runs.You could probably take multiple measurements and play triangulation games to get the error to, or under, one mm given enough time effort and money.
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This is optical:
http://www.topconpositioning.com/products/total-stations/con...
"can measure in reflectorless mode up to 500m at an incredible 3mm + 2ppm accuracy."
A typical GPS:
http://www.topconpositioning.com/products/gps/modular-soluti...
Static H: 3mm +0.5ppm (x baseline length) V: 4mm +1.0ppm (x baseline length)
So GPS gives you lower PPM than optical for long runs but lower accuracy on short runs.
You could probably take multiple measurements and play triangulation games to get the error to, or under, one mm given enough time effort and money.