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

24 CHAPTER 3. RASTER OBSERVATION (CAM01)
directory (for file saving, sharing data with external executables etc. . . ). Identify the
location of the CISP data product. The actual CISP data product name is the first
argument to spdtoscd and the keyword dir is set to the directory containing the CISP
file. If you are working from the CD-ROM you will need to copy your data products to
disk space – see Section 10.1.
In our example the CISP file is called cisp02600506.fits and it is located in the subdirectory
test/ of the CIA installation directory:
CIA> spdtoscd, ’cisp02600506.fits’, sscd, dir=’$cia_vers/test’, /nowrite
When spdtoscd is finished we have created a multitude of data structures in CIA’s memory.
There is a simple bi-level hierarchy to these structures. At the bottom level there is
one data structure for all the data from a CAM STATE, these data structures are called
SCDs. In the case of a raster observation, a STATE is time spent in each pointing of
CAM. So in our example, there are at least 32 SCDs: 4 CONFIGURATIONs, each of a
2×4 raster, adding up to 32. In order to keep track of all these SCDs there is a top level
data structure – this is called an SSCD. It holds relatively few data as its primary function
is to catalogue its component SCDs. The variable sscd returned by spdtoscd contains
the unique SSCD name.
CIA> print, sscd
CSSC026005060101_02022714575801
This name is used to address the data in CIA. Note that the SSCD and SCD are not
regular IDL structures, but are implemented in CIA using handles.
3. Remember from Section 3.1 that there is more than one CONFIGURATION in our example
data set. This can be illustrated with the routine sscd info. This routine operates on
the SSCD and lists the characteristics of its component SCDs. In doing so it is also listing
the characteristics of all the STATEs in the AOT.
CIA> sscd_info, sscd, /deg
48 SCDs in the SSCD: CSSC026005060101_02022714575801
seq channel mode fltrwhl pfov tint gain offset size ra dec
0 LW IDLE LW2 6.0 25.20 1 512 1 180.498 -18.849
1 LW IDLE LW2 6.0 2.10 2 512 1 180.498 -18.849
2 LW OBS LW2 6.0 5.04 1 512 1 180.498 -18.849
3 LW OBS LW2 3.0 5.04 1 512 46 180.498 -18.849
4 LW OBS LW2 3.0 5.04 1 512 24 180.490 -18.871
5 LW OBS LW2 3.0 5.04 1 512 24 180.482 -18.893
6 LW OBS LW2 3.0 5.04 1 512 24 180.473 -18.915
7 LW OBS LW2 3.0 5.04 1 512 23 180.450 -18.908
8 LW OBS LW2 3.0 5.04 1 512 24 180.458 -18.886
etc...
If you look at the output of sscd info you will see more than the expected 32 SCDs.
These others correspond to STATEs where CAM is busy doing other things other than