Moasure

• An intertial measurement device for getting areas, shapes, distances - great for initial surveys or estimating - https://www.moasure.com/products/moasure-one. Not GPS.

This brings up the question - how accurate is RTK GPS?

• To mm of relative coordinates, but 1-2 cm for absolute coordinates.
• DIY RTK station - GNS receiver + support - [1]
• $179 RTK module from Sparkfun [2]