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

15.4. AUXILIARY CALIBRATION DATA 177
.
HavealookattherestorevariablePSF:
CIA> help, psf, /str
** Structure , 7 tags, length=1809884, refs=1:
PFOV FLOAT 3.00000
WAVELENGTH STRING ’LW2’
RESOLUTION FLOAT 0.142857
STEP FLOAT 0.142857
IMA FLOAT Array[32, 32, 441]
XCEN FLOAT Array[441]
YCEN FLOAT Array[441]
The field .IMA holds the actual theoretical PSF image, and .XCEN and .YCEN the coordinates
of the center of the PSF. The step size and resolution of the PSFs are given by .STEP
and .RESOLUTION. respectively.
15.4.2 Observed PSFs
The observed PSFs were generated by replacing theoretical computed PSFs with the best fitted
observed PSFs. At the date of publication of the CIA User’s Manual observed PSFs had only
been generated for the 1.5 ′′ PFOV. The observed PSFs are stored as IDL save sets and have
the following shape psf filter pixel-field-of-view simul.save, e.g. psflw10 1p5as simul.save. They
have the same structure as the theoretical PSFs described in Section 15.4.1. The observed PSFs
may be retrieved along with the theoretical PSFs.
15.4.3 House keeping and CAM wheels data
CAM wheels position data are distributed in CIA as simple text files. These files are used by routines
such as convert wheel back to determine the wheel position from the wheel description
– see Section 16.5 for an example.
To access these files directly follow the procedure below.
1. Firstly, let’s have a look at the hk wheels *.txt files.
In unix these files can be found in. . .
CIA> hk_dir = ’$cia_vers/tables/’
...and in VMS in...
CIA> hk_dir = ’CIA_TABLES:’
Now list the contents of hk dir:
CIA> cd, hk_dir
CIA> dir, ’hk_wheel_*.txt’
hk_wheel_1.txt hk_wheel_3.txt hk_wheel_5.txt
hk_wheel_2.txt hk_wheel_4.txt hk_wheel_6.txt