1. Naval Research Laboratory, Washington, D.C. 20375-5340, Georgetown University, 3900 Reservoir Road, Washington, D.C. 20007, Geocenters, Inc., 10903 Indian Head Highway, Ft. Washington, Maryland 20744, Kaman Sciences Corp, 2560 Huntington Avenue, Alexandria, Virginia 22308, and Nova, Inc., 1900 Elkin Street, Suite 230, Alexandria, Virginia 22308