UNAVCO has installed a surveyor's quaility GPS system at SummitStation? for researchers' use. The Trimble NetRS (http://facility.unavco.org/project_support/polar/whatnew/NetRS.pdf) is installed at the GreenHouse? and supports surveys up to 5km away. More information can be found at http://facility.unavco.org/project_support/polar/summit/base.html.