MEASUREMENT OF THE INFRARED HORIZON OF THE EARTH.

Abstract : Radiance measurements of the Earth's horizon in three infrared spectral regions were made during two Aerobee rocket flights at White Sands Missile Range, New Mexico. Preliminary results indicate equivalent blackbody radiation temperatures in the CO2 band (14.0 - 15.6 microns) varied from 231K to 239K; in the atmospheric window region (10.2 - 11.8 microns) from 205K to 287K; and in the rotational water vapor band (19.5 - 31.8 microns) from 206K to 239K. Numerous dropouts due to clouds are apparent in the atmospheric window and water vapor bands, while no such effect is evident in the CO2 band. The infrared radiometer, stellar aspect sensor and vehicle attitude control system are described, and actual traces of the horizon profiles and outputs from the stellar aspect system are included. (Author)