Chief, Cartography & Remote Sensing Unit, Infrastructure Branch, Natural Resources & Energy Division, Department of Technical Cooperation for Development, United Nations since 1990. Senior Economic Affairs Officer, Chief, Remote Sensing Unit, Department of Technical Cooperation for Development, since 1981. Adjunct Professor, Hunter College, Department of Geology & Geography, Visiting Professor, University of Hamburg, Visiting Scientist, Foundation in Maritime Transportation ^ Shipbuilding, Geesthacht, Germany.
Ocean Economic & Technology Office, United Nations, New York, 1974-1976. Assistant Professor, College of Marine Studies, University of Delaware, 1971-1975. National Academy of Sciences Association, NASA Goddard Space Flight Center, Greenbelt, Maryland, 1969-1971.