This paper discusses the validation of measurements of O-3 distributio
n in the Earth's atmosphere made by the Millimeter-wave Atmospheric So
under (MAS), a component of NASA's ATLAS spacelab shuttle package. Mea
surements of 184 GHz O-3 emission from the Earth's limb at tangent alt
itudes between 20 and 80 km were made with a 50 channel radiometer hav
ing a spectral resolution of 200 KHz. In three missions the emissions
of O-3, H2O: ClO, and O-2 were measured between 70 degrees S and 70 de
grees N latitudes. O-3 mixing ratio calculations and error analysis we
re performed with the Rodgers optimal estimation method. Data binned i
n 128 s batches yield mixing ratio profiles with an altitude resolutio
n of 7 km at the O-3 peak and an estimated accuracy of 5%. Additional
retrievals made with all data from each mission binned in 50 latitude
zones yield mixing ratios with about 5 km altitude resolution and some
what improved accuracy. Comparisons with coincident measurements from
other space platforms indicate a general agreement within approximatel
y 5%. The data are publicly available through the German Remote Sensin
g Data Center.