ACE-FTS Instrument (interferometer side)

The Fourier Transform Spectrometer (ACE-FTS) is the primary instrument selected for the Atmospheric Chemistry Experiment (ACE) mission onboard the SCISAT satellite. The ACE-FTS instrument is designed to simultaneously measure the temperature, trace gases, thin clouds, and aerosols found in the atmosphere using a solar occultation technique. For this technique to work, the orbiting satellite must first point to the Earth's horizon during sunrise or sunset. As the sun "moves" through the thin band of atmosphere at the horizon, its rays are partly absorbed by the various gases in the atmosphere at different altitudes. It is these gases and their distribution that the high-resolution, infrared ACE-FTS will measure. Thus, as the instrument observes the rising or setting sun, it can perform its measurements throughout the whole thickness of the atmosphere. Aerosols such as those caused by gases ejected by volcanoes will also be measured. The ACE-FTS was built in co-operation with the Canadian Space Agency by ABB Bomem of Québec City. Funding for the ACE mission, including both Canadian instruments, was provided by the Canadian Space Agency’s Space Science Program. (Credit: Canadian Space Agency)