Simulators are frequently used in astronomy to model the behaviour of a telescope and instrument, and to simulate its data products.
They are essential for software interface testing, observation planning and testing of the data pipeline. It is common practice to develop a simulator for a particular end-to-end data path, and the first MIRI simulator (Specsim for the MRS) was written in this way. However, the versatility of MIRI means there is a large potential for duplicated code.
Writing a suite of small, communicating data simulators (rather than one end-to-end package) reduces the amount of duplicated code; especially for multi-mode instruments like MIRI. Each simulator is designed to simulate one physical system and to solve a particular problem once:
• MOSim, MirimSim and Specsim simulate specific instrument modes and generate detector illumination information.
• SCASim then simulates the behaviour of the detectors.
It was thus decided to develop a general MIRI simulator as a communicating suite of packages. This MIRI simulator is being developed in Python by the European Consortium. It will include all functionalities of the instrument, taking into account all of the detectors effects and will be distributed worldwide.
In parallel, MICE, the French Centre of Expertise for MIRI, has developped an IDL simulator for the coronagraphs, the low resolution spectrograph, and the imager. This simulator can be used upon request and scientists who would make use of it should contact directly MICE.