Title :
Estimates of atmospheric attenuation sensitivity with respect to absolute humidity at 337 GHz
Author :
Galm, James M. ; Merat, Francis L. ; Claspy, Paul C.
Author_Institution :
Dept. of Electr. Eng. & Appl. Phys., Case Western Reserve Univ., Cleveland, OH, USA
fDate :
7/1/1990 12:00:00 AM
Abstract :
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. The ambient and dew point temperatures were recorded concurrent with the relative attenuation measurements. 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 estimates to a previous investigation at the same frequency indicates general agreement
Keywords :
atmospheric humidity; atmospheric measuring apparatus; tropospheric electromagnetic wave propagation; 337 GHz; 640 m; THF; absolute humidity; ambient temperatures; atmospheric attenuation sensitivity; clear-air relative attenuation measurements; dew point temperatures; field transmissometer; near-millimeter wave laser; Atmospheric waves; Attenuation measurement; Frequency estimation; Laser excitation; Optical attenuators; Optical pumping; Optical recording; Optical sensors; Pump lasers; Temperature sensors;
Journal_Title :
Antennas and Propagation, IEEE Transactions on