Keywords: RadioPropagationResearch 006.jpg National Bureau of Standards now NIST Field Station at Gun Barrel Hill Colorado with three giant Wientsburg parabolic antennas used in microwave propagation research Information taken from NBS research in radio propagation STR 1859 National Institute of Standards and Technology National Institute of Standards and Technology PD-USGov-NIST PD-USGov National Bureau of Standards National Institute of Standards and Technology Radio waves Communication Parabolic antennas Radar antennas |