The ISOPHOT-Interactive Analysis (PIA), a calibration and scientific analysis tool

Carlos GABRIEL
ESA-SAI

Session ID: T2.05   Type: oral

Abstract:

The PHT-Interactive Analysis, PIA, is a calibration, scientific analysis and visualization tool for accessing and processing ISOPHOT data. ISOPHOT is one of the four instruments on board ISO, the Infrared Space Observatory, launched in November 1995 by the European Space Agency. ISOPHOT contains several sub-instruments for performing photometry, polarimetry, and imaging in the infrared range of [2.-240.] microns, and low resolution spectro-photometry in the range [2.-12.] microns. PIA is an IDL (Interactive Data Language) based package. It comprises more than 1200 routines imbedded in a user friendly graphical interface. All the capabilities of input/output, processing and visualization can be reached from window menus. The capabilities are built in for all sub-systems in all the different levels of data reduction, starting from voltages CRE output in digitized form, as coming from the telemetry, to the final level of images, 3-D images, spectra, multi-filter, multi-aperture analysis. PIA runs on every UNIX or VMS platform under different IDL versions, from IDL 3.6 upwards. The software is used at the same time for ISOPHOT operation purposes as for calibration and scientific analysis. Input for the PIA are all the products in FITS format, as delivered by ESA to the ISO observers, following performance of their observations. Also PIA internal (IDL/XDR format) and FITS files, produced by the PIA package itself, are used as input by the PIA. Output are observations on every reduction level in FITS or PIA internal format. PIA can save/restore data at every reduction step. This gives the possibility of interrupting and restarting the data analysis at any point. In addition, the PIA produces text, plot and image output to files or to printers in several different formats (PS, GIF, Sun, TK, HP). PIA offers different processing modes, fully interactive, semi-automatic or fully automatic. All the parameters used for calibration and data reduction are changeable, most of them testable. Documentation is available on-line from the package as a hypertext help system. A general user manual, as well as case sensitive help informations are accessible from the different windows. A "Guided tour" chapter is also provided to help first time users. Leaving the PIA graphical interface does not prevent the user from accessing directly all the package buffers and structures. In this way, the full capability of all IDL routines and libraries can be used to be added to those already present in the PIA. Special chapters in the documentation should help users who are familiar with IDL, to exploit this capability. PIA is available for free to all astronomers wishing to use it for ISOPHOT data reduction and analysis.





Patrick P. Murphy
Wed Sep 11 10:08:29 EDT 1996