For survey applications, the Center has a Trimble 5600 robotic total station, two 5700 geodetic-grade receivers, a 5800 integrated receiver/antenna, two survey controller units, five GeoExplorerCE XM devices and two GeoExplorer XH devices for hand-held surveying to meter accuracy. CAST, in cooperation with DCI, Inc of Little Rock, AR, operates a Trimble NetRS base station (owned by DCI) mounted on the roof of the Science and Engineering Building. When surveying within 20 miles of campus, this base station provides real-time millimeter level accuracy to the two 5700 and 5800 receivers when operated. GPS observation data is also archived and made available to the public for post-processing via ftp transfer.