The compass direction (in degrees clockwise from true north) that a rocket's exhaust plume points after ignition, as observed from above by a geostationary satellite. Plume azimuth reveals the rocket's flight trajectory direction within seconds of ignition — easterly azimuth for typical low-inclination launches, southerly for polar/SSO, etc. LaunchDetect derives plume azimuth from the thermal anomaly's elongation axis in ABI band 7 imagery.
In LaunchDetect
Combined with the known launch pad position, plume azimuth provides an immediate estimate of the orbital inclination the rocket is targeting.