Gas flaring monitoring from space using the ATSR instrument series

Gas flaring flames are characterised by high temperatures and ATSR instruments are equipped with the appropriate spectral bands to detect them. In order to monitor gas flaring on global scale a new active flame detection scheme from satellite night-time Short Wavelength Infra Red measurements (SWIR, 1.6 μm) has been developed and tested using the Along Track Scanning Radiometer (ATSR) family measurements. The new algorithm, called ALGO3, is based on the verified assumption that, at SWIR wavelengths, the background contribution to the night-time total radiation measured by ATSR is negligible, while that emitted by active flames is fully detectable. ALGO3 products are suitable for detecting gas flares, due to their peculiar high temperature/small area flames. Flaring sites have been discriminated according to time persistency criteria, i.e. location for which hot spots are found at frequencies higher than 4 times a year are assumed to be industrial settlements. Continuity and consistency between the ATSR missions has been verified, and results relative to 1991–2009 time window are reported. Validation of flaring site discrimination has been performed by visual inspection of high resolution Earth surface images. The comparison of ALGO3 retrievals with light count data from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) show very good agreement.