Not addressed in the ISOCAM Observer's Manual is the source displacement on the detector array. The displacement through the three polarizers P1, P2, P3 relative to the source position seen through the hole measurement (H) is:
Details of the set up of polarization observations will be done in close contact with the resident astronomer for ISOCAM. Targets having a sources flux of more than a few milli Jy it is recommended to use a 2 by 2 raster in 2 cycles with 40 exposures per polarizer and 25 exposures per hole measurement. Such an observation will take of order 3600s for a single filter measurement.