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

15.3. CALIBRATION DATA STRUCTURE (CDS) 175
Figure 15.1: cds display window.
As you can see from the above, no user-friendly strings exist in the CDS – as stated earlier
calibration is handled internally by CIA so usually the innards of the CDS are not touched by
a CIA user. For completeness, an example of how to convert the coded data into a readable
format follows.
If we want to know the pixel unit of intensity, it has to be converted to string:
CIA> print, string( dark_data[0].bunit )
ADU/G/s
Furthermore, data such as GAIN are in telemetry coded format and also have to be converted:
CIA> print, convert_gain( fix( dark_data[0].gain ) )
2
However, displaying the actual DARK image is easy:
CIA> tviso, dark_data[0].image[*,*,0]
For an example on how to extract PSF images from a CDS see Section 16.5.
15.3.3 cds display
If you simply want to browse through the contents of a CDS, then cds display is the tool for
you. It may be called by simply typing cds display, without arguments, on the CIA command
line. cds display will then prompt you for the name of a CDS stored on disk. Alternatively,
if you have a CDS in memory it may be supplied as an argument. For example, to view the
DARK CDS created in the previous section: