ESTIMATES OF ATMOSPHERIC ATTENUATION SENSITIVITY WITH RESPECT TO ABSOLUTE-HUMIDITY AT 337 GHZ

A 640-m field transmissometer was operated for a three-day period during late July 1986. Using an optically pumped, near-millimeter wave laser as the source, clear-air relative attenuation measurements were collected at an operating frequency of 337 GHz. Concurrent with the relative attenuation measurements, the ambient and dew point temperatures were recorded. An expression was synthesized to provide absolute humidity measurements from the recorded temperatures. By assuming static attenuation due to atmospheric constituents other than water vapor, the sensitivity of attenuation to absolute humidity at 337 GHz was estimated at a number of temperatures. Comparison of these new estimates to a previous investigation at the same frequency indicates general agreement. © 1990 IEEE