AbstractSubmeter Mapping...Really? The Revenge of the Shift Track: GPS Technology Author(s): Joel Cusick Using a global positioning system (GPS) receiver has never been easier. Accuracies claimed by various receiver manufacturers can be verified, and under good GPS conditions, mapping-grade GPS can easily map at the submeter range, while recreational autonomous GPS can exceed the accuracy of the typical USGS topographic quad. Most mistakes are made when basic fundamental field practices are disregarded and when the importance of geodetic datums are ignored. Have you ever run aground on a datum mismatch either in the field or in the GIS? This talk reemphasizes the importance of some basic field techniques, regardless of the receiver make or model, and controlling the dark side of GPS—datums and reference frames. Using a quote from Yoda, fictional character from Star Wars, "Happens to every guy sometimes this does." Joel Cusick National Park Service GIS 240 W. Fifth Ave. Anchorage, AK 99501 US Phone: 907-644-3549 E-mail: joel_cusick@nps.gov |