One column of ISOCAM LW detector, column 24, continues to be always at
0V. For this reason during the phase II data entry of guaranteed time
and open time (pre-launch call) holders we recommended to use a small
raster instead of a staring or beam switching observations for any C05
measurements.
During C05 in-flight calibration measurements we detected, for the
three polarizers, a several-pixel, polarizer-dependent, displacement
(D [arcsec]) of:
polarizer 1 : D(p1) = (-3, -10.5) polarizer 2 : D(p2) = (+9, 0.0) polarizer 3 : D(p3) = (-3, -4.5)
Together with the column 24 problem it is recommended to use at least
a 2 x 2 raster with about a quarter array step size, e.g. M=N=2;
dM=dN=8pixels.
The recommended observing strategy for C05 is the raster mode.