Many numerical simulations and theoretical work have been carried out in order to decide the most suitable line and wavelength samples for the instrument. Numerical experiments have also been carried out for exploring the diagnostic capabilities of the instrument in the different observing modes. The scientific exploitation of the data has been remarkably successful.
A proximity electronics box goes in the optical bench that is in charge of reading out the cameras and of the high-voltage power supply of the étalon (wavelength is tuned by means of high voltage between -3000 and 3000 V). This box is pressurized to maintain laboratory conditions during the flight. Since the electronic components are commercial they would not work properly under the hostile conditions of the stratosphere.
The main electronics which is separated from the optical bench is responsible for the whole behavior of the instrument. As in the proximity electronics case, this main electronics box is also pressurized.
The software is made up of three modules, namely the control software (CSW), the data-processing software (DSW), and the EGSE (electrical ground support equipment). The latter is developed together with the IAC group.