[tyw]

is centimeter accuracy even possible with GPS? http://www.gps.gov/systems/augmentations/ cites 10-15 centimeter accuracy under their NDGPS modernization efforts, but don't even say they've gotten there yet.

[chrissmithuk]

It's not possible, even with pretty ideal conditions.

Edit: I excluded RTK stuff in that comment :)

[Nrsolis]

Welll.....that's not strictly true. If you've got an environment free of multipath, you use differential or WAAS-enabled GPS receivers, you can get pretty good accuracy.

Source: http://www.oc.nps.edu/oc2902w/gps/gpsacc.html

Please note that all of these things depend on many factors and can be considered nearly "heroic" measures when it comes to position accuracy, but the Navy has historically been pretty damn concerned about knowing where their assets are and is somewhat obsessive about error-factors where that's concerned.

[MrUnderhill]

With orbit and clock corrections delivered to the receiver in ~real time (such as Fugro's G2), you'll get <10cm (95%) on a standalone receiver.

[Nrsolis]

translation: I didn't know about RTK before I posted. Thanks for schooling me.

[stefantalpalaru]

It is, using RTK (real time kinematic) and 2 different receivers: http://www.kickstarter.com/projects/swiftnav/piksi-the-rtk-g...

[ye]

RTK.

http://en.wikipedia.org/wiki/Real_Time_Kinematic