Daedalus Airborne Thematic Mapper ( ATM) data, obtained between 12.14GMT and 13.44GMT on 19 June 1984 as part of the Natural Environment Research Council's Airborne MSS-84 campaign, have been used to calculate sea surface temperatures in the western English Channel. Quantitative analyses of the thermal infrared data are discussed with particular reference to boat trials and eddy structures. A method to calculate brightness temperatures and their associated errors is also discussed along with a review of two atmospheric correction procedures for the estimation of sea surface temperatures from thermal infrared data. An apparent asymmetry in the thermal infrared data is considered in the context of the atmospheric correction model used. Results show that the asymmetry can be compensated by using an effective scanner tilt angle.