AATSR had a single operational mode, MEASUREMENT mode, for nominal routine operations. When in MEASUREMENT mode, science data were generated and distributed. For most of the time, AATSR was in MEASUREMENT mode and required no commanding from ground for specific observations.
Whilst in MEASUREMENT mode, the only interruptions to the flow of science data were due to:
Information on the occurrence of these events is given in the Mission Operations Overview.
Several support modes were used to achieve or maintain full instrument operational conditions:
In HEATER mode, the Instrument Control Unit was running, and monitoring and controlling the instrument. All instrument subsystems were running and at operational temperatures, only the generation of measurement (science) data was paused. AATSR was commanded to HEATER mode during Envisat Orbit Control Manoeuvres.
A summary of the usage of the different modes for AATSR is given in the Mission Operations Overview.
Full information on all the events occurring during the AATSR mission lifetime can be found in the Envisat End of Mission AATSR Events Report.