Accession Number : AD0704584
Title : DESIGN, DEVELOPMENT, AND INITIAL MEASUREMENTS OF A 1.4-mm RADIOMETRIC SYSTEM.
Descriptive Note : Rept. for Aug 67-Aug 68,
Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
Personal Author(s) : Johnson,Walter A. ; Mori,Tsutomu T. ; Shimabukuro,Fred I.
Report Date : 15 FEB 1970
Pagination or Media Count : 24
Abstract : The development of a 1.4-mm heterodyne radiometric system and the initial measurements taken with it are described. The delta T of the system at the antenna terminals was approximately 18.6 K for a 0.25-Hz post-correlation noise bandwidth. Measurements show that the attenuation through the atmosphere at this wavelength is primarily due to water vapor, and an estimate of the zenith attenuation is given by A(dB) = 2.8 w, where w is the precipitable water in centimeters. Measurements of the antenna half-power beamwidths using the sun as a source show that at 1.4 mm, the atmospheric turbulence effects are not appreciable for observations through the atmosphere at zenith angles less than 45 deg with a 15-ft antenna. (author)
Descriptors : (*RADIO ASTRONOMY, MILLIMETER WAVES), (*MILLIMETER WAVES, *RADIOMETERS), ATTENUATION, WATER VAPOR, RADIO TRANSMISSION, ATMOSPHERIC MOTION
Subject Categories : Astrophysics
Distribution Statement : APPROVED FOR PUBLIC RELEASE