Since ISO is a pre-planned observatory, all observations have to be specified in full detail in advance. ESA has developed the Proposal Generation Aids, a software tool which permits observers to prepare their observations and enter target and observation parameters. An updated version of this tool will be used by proposers during Phase 2 of proposal submission. The two phases of proposal submission are described in the SUPPLEMENTAL CALL FOR OBSERVING PROPOSALS - POLICIES AND PROCEDURES.
Although for Phase 1 of proposal submission, the full details need not to be included in the proposal, observers have to know about all parameters needed to specify an observation and how to calculate the corresponding observing time.
Each of the four instruments has a number possible operating modes. To simplify the specification of an observation and to allow users to specify their observations in terms familiar to them, a set of astronomically useful operating modes of the instruments has been defined - the observing modes.
Each observing mode of an instrument is represented by an Astronomical Observation Template - AOT. Each AOT is designed to carry out a specific type of astronomical observation. In the Proposal Generation Aids, the AOT is the only user interface to specify an observation. To the user of the software, it appears as a set of panels containing fields where the actual parameters have to be filled in.
An observation, that is a combination of target and specific observing parameters, is specified by the following set of parameters: