New from Leica Geosystems,Inc. is a "smart" DGPS antenna which can provide highlyaccurate position and velocity inputs to a PC computer. The apMK31is a single integrated unit that contains a 12-channel GPS receiverand a two-channel beacon DGPS receiver, all sealed in a low-profileweatherproof, fiberglass radome. The antenna unit connects viaa standard cable to a PC. It automatically receives signals from the GPS satellites and differentialerror-correction data from marine radiobeacon broadcasts, andcalculates the boat's position to within three to ten feet. The apMK31 DGPS an tenna can also serve as a stand-alone sensor to provide input for integrated navigationsystems, radars and echosounders. Leica Geosystems, Inc., Torrance,CA; (310) 791-5300.