ISOCAM Interactive Analysis User's Manual Version 5.0 - ISO - ESA

Chapter 9
The data products and CIA data
structures
In this chapter we will look at how the data are stored in the data products as FITS files, how
these data products are named and how they relate to CIA Data Structures (see Part III for a
more detailed account of the CIA Data Structures).
9.1 Data product filename convention
Observers who have not obtained their data via IDA will have to deal with the filename convention
that has been applied to the data product files on the ISO CD-ROM. This is due to
a community requirement that the length of the filenames comply with the DOS convention
of a maximum of eight characters, with a three character extension. The file datalist.txt (see
Section C.2.2) lists the official names of the files on the CD-ROM along with the actual abbreviated
name used. Note that in the CIA User’s Manual, so-called observation data product files
(found in the CD-ROM directory /products/pmmmmmmm/nnnxxxyy) are always referred to
by their filename root, even though the official name is the root with nnnxxxyy appended to it,
e.g. CIER refers to CIERnnnxxxyy.
9.2 Data products as FITS files
All ISO data products, whether retrieved from IDA or delivered on an ISO CD-ROM, are FITS
files. The features of these FITS file are described in the ISOCAM Handbook 1 .TheISO Data
Product Document lists the header and binary table keywords for all ISO files. From the table
of contents of the ISO Data Product Document you can see that the files are grouped in a
particular way. Section 9.3 will help you understand the grouping and find the FITS file details
you want in the ISO Data Product Document.
9.3 Relating data product types to filenames
You can consider the data products to be organised into five groups. Raw Data, Standard
Processed Data, Automatic Analysis Results, Calibration Data and Auxiliary Data. Further
1 Also a good reference is Harten R.H., 1988, The FITS tables extension, A&A Suppl. Ser. 73, 365-372.
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