GPR LINKS
Gary Olhoeft: http://www.g-p-r.com/
Steven Arcone: http://gpr.osu.edu/committee2006_files/Steven_Arcone.htm
GSSI: http://www.geophysical.com/
NRCS: http://soils.usda.gov/survey/geography/maps/GPR/
Wikipedia: http://en.wikipedia.org/wiki/Ground-penetrating_radar