The accuracy of _2}$ cameras is significantly determined by the ability to obtain an accurate calibration. This work presents a real-time continuous calibration method for _2}$ cameras with a moderate resolution spectrometer by taking realistic radiative transfer into account. The effectiveness and accuracy of the proposed method have been verified through simulations and experiments. The calibration error can be reduced by about 20–80% compared with the commonly used cell calibration, especially for situations of long distance, poor visibility, or optically thick plumes.

(a)   Simulated DOD response of a UV camera system to the plume AOT and _2}$ CD for two different distances (1 and 2 km) and three different visibilities (10, 20, and 50 km). Colors represent the magnitude of DOD. (b) Camera calibration curves calculated with the sky spectrum data recorded by the UV spectrometer in conditions of different AOD and visibility.