The HFI DPC
The HFI DPC has been organized into three different "Levels": 1, 2, 3, 4 and "S".
(L1): consists in receiving the telemetry and ancillary data files and ingesting them into the DPC database. This involves decompressing, in some cases changing data formats, computing the time of individual data samples from the time of the compression slices, but otherwise no processing proper. Other steps are:
- data ingestion (science, HK, ancillary, other?)
- construction of ToS in science data group
- pointing interpolation
- construction of other TOI and ROI objects from AHF, ...
(L2): this is where the data are processed from timelines into maps. The main processing steps are
- Timeline (or Time-Ordered Information = TOI) processing, which includes conversion from ADUs to engineering units (Volts), demodulation, deglitching, conversion from engineering to physical units (Watts), removal of known systematic effects (non-linearities, 4K lines, Jumps, ring flagging), removal of the instrumental signature (time transfer function)
- map-making: projecting the TOIs onto all-sky maps, etc. etc,
- Noise Estimation
- Focal Plane Reconstruction
- Diffuse Calibration
- Systematic Effect Removal
(L3): This is where the data in the form of frequency maps are converted to component maps, and where the maps used to create power spectra of the CMB. Much of this is done in common with the LFI, and is further described
Level 4 is the "Archive Level".
Level S is the so-called "Simulation Level".
(Planck) High Frequency Instrument
Data Processing Center
Time of Sample
Ring-Ordered Information (DMC group/object)
Attitude History File
EMI/EMC influence of the 4K cooler mechanical motion on the bolometer readout electronics.
Cosmic Microwave background
(Planck) Low Frequency Instrument