Total Ozone Mapping Spectrometer (TOMS)
Total Ozone Mapping Spectrometer (TOMS)

The Total Ozone Mapping Spectrometer, launched in July 1996 onboard an Earth Probe Satellite (TOMS/EP), continues NASA's long-term daily mapping of the global distribution of the Earth's atmospheric ozone. TOMS/EP will again take high-resolution measurements of the total column amount of ozone from space that began with NASA's Nimbus-7 satellite in 1978 and continued with the TOMS aboard a Russian Meteor-3 satellite until the instrument stopped working in December 1994. This NASA-developed instrument, measures ozone indirectly by mapping ultraviolet light emitted by the Sun to that scattered from the Earth's atmosphere back to the satellite. The TOMS instrument has mapped in detail the global ozone distribution as well as the Antarctic "ozone hole," which forms September through November of each year.