When crude oil is extracted from onshore and offshore oil wells it brings with it raw natural gas to the surface. In Nigeria a vast amount of this is burned directly into the atmosphere. The hazardous air pollutants emitted from gas flaring have been shown to severely impact human health and the ecosystem.
The Gas flare tracker uses satellite data measured by the VIIRS instrument (Visible Infrared Imaging Radiometer Suite) on board the Suomi National Polar-orbiting Partnership (S-NPP) satellite.
The VIIRS uses a Nightfire (VNF) algorithm to detect and characterise active fires during night-time. Every 24 hours, the VNF updates a database with geo-located radiant heat, footprint area and temperature estimates, from active fires detected by the VIIRS instruments.
The Gas Flare Tracker downloads this data for Nigeria and removes readings with temperatures below 1400 degrees kelvin. A calibration method outlined below is then applied to this data.