PLANCK Calibrated Time Ordered Data
A major step in the Planck data processing is to create
the calibrated time-ordered data file.
The significant steps are:
Tag (removal) of non-science data, bad & corrupt data - for HFI this includes
cosmic ray removal
Calibration data base (calibration history and parameters files
- absolute and relative) and alogrithms are applied to the unpacked
Determine, characterized, and remove instrument signatures.
This includes simple filtering such as the phase shift introduced
by time constants of the detectors and amplifiers
and alignment of the real times with the data samples.
There are potentially more complicated items such as removal of any cross-talk
(hopefully this is minimal)
More sophisiticated filtering and baseline removal
The goal here is to have a time-orderd data set which is calibrated
into physical units, has the significant features of the instrument
such as baseline drift and environmental sensitivities removed.
This calibrated data set is the input to the map making and
further downstream analysis.
This stage is usually only created from the raw data stream by the DPC
and only through a very limited number (e.g. 2 or 3) passes
because of the very large amount of effort and specific knowledge