The experiment concept involves the use of millimeter wave radiation the atmospheric oxygen to provide vertical sensing information to a satellite-borne radiometer. The radiance profile studies require the calculation of ray brightness temperature as a function of tangential altitude and atmosphere model, and the computer program developed for this purpose is discussed. Detailed calculations have been made for a total of 12 atmosphere models, including some showing severe warning conditions. The experiment system analysis investigates the effect of various design choices on system behavior. Calculated temperature profiles are presented for a wide variety of frequencies, bandwidths, and atmosphere models. System performance is determined by the convolution of the brightness temperature and an assumed antenna pattern. A compensation scheme to account for different plateau temperatures is developed and demonstrated. The millimeter wave components developed for the local vertical sensor are discussed, with emphasis on the antenna, low noise mixer, and solid state local oscillator. It was concluded that a viable sensing technique exists, useful over a wide range of altitude with an accuracy generally on the order of 0.01 degree or better.

The feasibility of a microwave vertical sensor depends on the uniformity of the radiometric temperature of the earth's O2 mantle at some operating frequency in the 60-GHz(5-mm wavelength) range. The essential properties of passive vertical sensors are examined. The characteristics of the 5 mm O2-band emission from the earth's atmosphere are analyzed. The potential accuracy of a 60 GHz O2-band vertical sensor is determined, considering both instrumental and O2 mantle uniformity limitations. To take the data required to evaluate the O2 mantle uniformity, a downward-looking radiometric instrument operating at 60.80 GHz was designed and built by Ewen-Knight Corporation. The design of the instrument is analyzed from the atmospheric physics and the instrument engineering viewpoints. The instrument, designated Experiment CRLF 739, was accepted for flight aboard the OAR satellite OV1-86; the details of interfacing the instrument with OV1-86 are discussed. (Author).

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References are presented on the subject of recent (1971-74) work on radio propagation through atmosphere at frequencies from 10 to 100 GHz.