GHGSat constellation

The GHGSat constellation is a commercial fleet of small satellites operated by GHGSat Inc. for facility-scale greenhouse gas monitoring, with the first satellite (GHGSat-D, also called Claire) launched on 2016-06-22 into a sun-synchronous orbit at approximately 500 km altitude.^[1][2] The constellation uses wide-angle Fabry-Perot spectrometers and SWIR absorption to measure methane and CO2 column concentrations at sub-facility spatial resolution (12 km swath, better than 50 m ground sampling on later satellites), enabling quantification of emissions from individual industrial sites including oil and gas facilities, coal mines, and landfills.^[2][3] Data products support matched-filter plume detection and flux estimation from identified emission sources.^[2] The constellation has grown through successive launches; by late 2025 the fleet included at least 15 satellites, with Teodor (C-14) and Laila (C-15) launched later that year.^[4][1] Tasking is commercially available. The exact operational count at any given date changes with the company's ongoing launch programme; per-satellite commissioning dates after launch are not detailed in public records.