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

42 CHAPTER 6. BEAM-SWITCH OBSERVATION (CAM03)
11 LW OBS LW10 1.5 2.10 2 512 22 295.462 50.517
12 LW OBS LW10 1.5 2.10 2 512 26 295.417 50.501
13 LW OBS LW10 1.5 2.10 2 512 21 295.417 50.501
14 LW OBS LW10 1.5 2.10 2 512 26 295.463 50.518
15 LW OBS LW10 1.5 2.10 2 512 22 295.463 50.517
16 LW OBS LW10 1.5 2.10 2 512 26 295.488 50.488
17 LW OBS LW10 1.5 2.10 2 512 21 295.488 50.488
18 LW OBS LW10 1.5 2.10 2 512 27 295.463 50.518
19 LW OBS LW10 1.5 2.10 2 512 21 295.463 50.518
20 LW OBS LW10 1.5 2.10 2 512 26 295.508 50.534
21 LW OBS LW10 1.5 2.10 2 512 2 295.508 50.534
22 LW IDLE LW10 1.5 2.10 2 512 25 295.463 50.519
23 LW OBS LW2 6.0 25.20 1 512 1 295.462 50.518
3. Get an overview of the SCDs:
CIA> sscd_info, sscd, /deg
There are quite a few SCDs here. Some of these we will discard.
For each source and reference pointing there are a pair of SCDs. The first SCD contains
on target data and the second SCD contains data from an intermediate step when ISO is
slewing. This SCD is considered to contain invalid data, though in reality the data may
be quite usable. Section 19.4.1 describes how such data may be incorporated into the data
reduction.
4. We normally can not use sscd clean on a beam-switch observation (see Section 19.4.1 for
a work-around). However, it is a simple manner of looking at the above list and deleting
the undesirable SCDs. STATEs that are IDLE and STATEs where the filter wheel was
not set to LW10 should be discarded:
CIA> scds = sscd_elem( sscd )
CIA> scd_del, scds[ 0:4 ]
CIA> scd_del, scds[ 22:23 ]
5. Now we must place the contents of the SSCD into a PDS. For a beam-switch observation
we use a BS PDS. This is created with get sscdbs.
CIA> bs_pds = get_sscdbs( sscd )
Note that there is one irregularity which sometimes arises in beam-switch observations:
some observers have programmed their observations in reverse! Section 19.3 tells you how
get sscdbs can be used to deal with this problem.
6. Now we can proceed with the calibration. We will perform the standard calibration steps
on the cube, i.e. bs pds.cube.
CIA> x3d, bs_pds