CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations)

CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) was a joint NASA and CNES mission that operated in a 685 km sun-synchronous low Earth orbit at 98.2 degrees inclination. The primary instrument was CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization), a two-wavelength polarisation-sensitive lidar that profiled the vertical distribution of clouds and aerosols globally.^[1][2]

The satellite launched on 28 April 2006 and operated in formation with the A-Train constellation for much of its mission, enabling co-located measurements with other Earth-observing instruments. CALIPSO's vertically resolved aerosol and cloud observations supported research in climate, weather, and air quality science.^[2] Science operations concluded on 1 August 2023, following an official end-of-mission declaration.^[3] Over 17 years of operations, CALIPSO collected lidar profiles that underpinned a large body of peer-reviewed research on aerosol transport, cloud microphysics, and radiative forcing.^[1]