Abstract

The Rocket Ozonesonde (ROCOZ) was originally developed in the early 1960’s and used for comparisons with ozone measurements from the OGO-4 satellite. In the 1970’s, measurements with ROCOZ were made in support of the BUV instrument on Nimbus-4 and the SBUV instrument on Nimbus-7. By 1982 problems with the ROCOZ payload led to an instrument improvement program at NASA Goddard Space Flight Center’s Wallops Flight Facility. Changes were made to the center wavelengths and spectral shapes of the ultraviolet filters. An integrated calibration facility was established¹, and new data reduction procedures were designed². Measurements of the repeatability of the current version of the instrument have been made², along with a description of the design of the radiometer³. The Improved Rocket Ozonesonde (ROCOZ-A) is propelled aloft by a Super-Loki booster rocket. At rocket burnout, the instrument and its carrier coast to a nominal apogee of 70 km, where the payload is ejected for deployment on a parachute. The radiometer measures the solar ultraviolet irradiance over its filter wavelengths as it descends through the atmosphere. The amount of ozone in the path between the radiometer and the Sun is then calculated from the attenuation of solar flux as the instrument falls. In addition, radar at the launch site measures the height of the payload throughout the descent. Knowledge of the solar zenith angle allows calculation of the fundamental ozone value measured by the radiometer, which is ozone column amount as a function of geometric altitude. Ozone number density is calculated from ROCOZ-A ozone measurements as the derivative of ozone column amount with altitude.

© 1990 Optical Society of America