Calibration with the ISOPHOT Interactive Analysis (PIA)

The ISOPHOT Interactive Analysis (PIA) software was conceived primarily as a tool to be used by the instrument team for the calibration of ISOPHOT. This is one of the four instruments on board the European Space Agency's Infrared Space Observatory (ISO), launched in November 1995. Actually, PIA has been extended to form an interactive tool for ISOPHOT data analysis in general, which can be distributed to all interested ISOPHOT observers. In this article we describe the philosophy behind the implementation of the processing sequences dealing with calibration observations, and how this leads to a general calibration assessment and finally the generation of calibration files, both for commanding the ISOPHOT instrument and reduction of the scientific data.