The AOTs are designed such that the observer has to specify only those parameters that are specific to the particular observation and target, e.g., source position (for solar system targets just the name ), wavelength range, flux density, desired signal-to-noise ratio. Parameters that require an in-depth understanding of the instrument are derived for the observer. Such parameters include, e.g. detector reset interval, amplifier gains and grating settings. They will be computed automatically from the observer's inputs and known instrument parameters. The whole observation will be translated automatically into spacecraft and instrument commands.
The AOT concept ensures that a particular observational task is executed in a way consistent with the properties of the instrument, that the necessary internal calibrations are performed, and that the resulting data are suitable for data reduction in the off-line processing chain. Observers have to specify the AOT input parameters fully and accurately.