Glossary
This page gives definition of some words commonly used in this Explanatory Supplement.
- ACMS : Attitude Control & Measurement Subsystem (AOCS)
- AHF : Attitude History File
- APID : Application Program Identifier
- APPL : Augmented Preprogrammed Pointing List
- calibration [HFI meaning]:
For a single detector, the absolute calibration is gain factor between the measured signal (watts absorbed by the detector) and the sky signal (in astrophysical units); can vary with time. For a set of detectors, the relative calibration is the difference in the calibration between detector pairs. The latter can be measured very accurately from the observations of the same source by different detectors, and is only slightly affected by the differences in the detector spectral responses, which are similar; the former requires observations of sources with well modeled spectral energy distributions or well known spectra, and requires that the detector's spectral bandpass also be well known.
- calibration [LFI meaning]:absolute calibration refers to the 0th order calibration for each channel, 1 single number, while the relative calibration refers to the component of the calibration that varies pointing period by pointing period.
- BEM : LFI warm electronics Back End Module
- CDMS : Command and Data Management System
- CDMU : Command and Data Management Unit
- CMB : Cosmic Microwave background
- CoP : Commissioning Phase
- CTR : Central Time Reference
- CUC : CCSDS Unsegmented Time Code
- DCE : Dilution Cooler Electronics
- DDS : MOC's Data Distribution System
- detector set [HFI meaning]: a detector set (aka detset aka quad) is a combinaison of two pairs of Polarization Sensitive Bolometers pairs at the proper orientations. The lists of detsets is given in here.
- DMC : Data Management Component, the databases used at the HFI and LFI DPCs
- DPC : Data Processing Center
- DPU : Data Processing Unit
- DQR : Daily Quality Report
- DTCP : Daily Tele-Communication Period
- effective beam [HFI meaning]: the effective beam at the map level is the overall angular response to the sky in a map pixel, which results from the combined effect of the instrumental response, the scanning strategy and the data processing.
- EOL : End Of Life
- ERCSC : Early Release Compact Source Catalog
- ESA : European Space Agency
- ESOC : European Space Operations Centre (Darmstadt)
- ESTEC : European Space TEchnology and Research Centre
- FEM : LFI cryogenic amplifying stage Front End Module
- FITS : Flexible Image Transfer Specification
- focal plane geometry [HFI meaning]
- FOG : Fiber Optic Gyroscope
- FOV : Field-Of-View
- FPU : Focal Plane Unit
- FWHM : Full-Width-at-Half-Maximum
- half ring difference : difference between the map built using the first half of each pointing period (typically 20 minutes of contiguous data) and the one built with the second half. This difference effectively removes the sky signal and most of the correlated noise, leaving only the noise components that have time scales of < ~ 20 min.
- HCM : Angular momentum Control Mode
- HEMT : High Electron Mobility Transistor
- HFI : High Frequency Instrument
- HPFTS : Herschel/Planck File Transfer System
- HPMCS : Herschel/Planck Mission Control System
- HPR [HFI meaning]: HEALPix Rings are introduced to avoid any additional binning of the data. We choose a sky pixelization as a basis for this ring making (HEALPix, Górski et al. 2005). HPR are therefore partial sky maps produced via a projection onto the sky of each single pointing period separately.
- HSK : House-Keeping data
- ICD : Interface Control Document
- IMO [HFI meaning]: the HFI Instrument MOdel is a central repository containing the models (or a link to them) and sets of fixed parameters used in these models describing for example how photons are gathered and transformed into data. IMO is oriented toward the data reduction and data processing. IMO is also used to monitor the instrument health. IMO represents at any time the official knowledge of the instrument response. It is intended to represent its best current knowledge agreed on by the project and applicable to the data processing. IMO does not represent the knowledge of the instrument. It is a knowledge of its response, (e.g. how photons are gathered and transformed into data). It is a simplified fraction of this knowledge directly useful to reduce the data. The IMO is restricted to the sole parameters used in the DPC. IMO does not contain timelines, nor maps, although it can provide links to calibration timelines (e.g. gain evolution) and calibration maps (e.g. beam maps). Models do not need to be unique (not a single model for a single process). Depending on the purpose for which they are used, they can be more or less sophisticated. (e.g. bolometer models, beam representations, very simplified for first assessment of pointing parameters, ...). IMO does not choose between them : it contains the parameters for each of them at the same time. See HFI RIMO.
- IOT : Instrument Operation Team
- JFET : Junction Field Elect Transistor
- LEOP : Launch & Early Orbit Phase
- LFI : (Planck) Low Frequency Instrument
- LOBT : Local On Board Time
- LOS : Line Of Sight
- mission [HFI meaning]
- MOC : [ESA's] Mission Operation Center [Darmstadt, Germany]
- NET : Noise Equivalent Temperature
- OBT : On-Board Time
- OD : Operation Day definition is geometric visibility driven as it runs from the start of a DTCP (satellite Acquisition Of Signal) to the start of the next DTCP. Given the different ground stations and spacecraft will takes which station for how long, the OD duration varies but it is basically once a day.
- optical beam [HFI meaning]
- P/L : Payload
- PAU : Pre_Amplification Unit
- PBR [HFI meaning]: Phase Bin Rings provide a compressed and higher signal-to-noise ratio rendition of the original Time Order Data
- PI : Principal Investigator
- PLA : Planck Legacy Archive
- PLM : Payload Module
- PO : Physical Optics
- POI : Phase-Ordered Information (DMC group/object)
- polarization leakage [HFI meaning]: in general, systematic effects mix the I,Q,U signals. Given the amplitudes of the sky signals, leakage from temperature to polarisation can be dramatic for polarisation analysis.
- PPL : Pre-programmed Pointing List
- PPLM : Planck Payload Module
- PSM : Planck Sky Model
- PSO : Planck Science Office
- PTD : Physical Theory of Diffraction
- PUS : Packet Utilisation Standard
- RAF : Raw Attitude history File
- REBA : LFI Radiometer Electronics Box Assembly
- REU : Readout Electronic Unit
- RFQM : Radio Frequency Qualification Model
- ring [HFI meaning]: at the HFI DPC level the ring is the time intervalle between two First Thurster Firings as defined in AHF description document. It thus starts with a satellite slew and thus an unstable pointing period and continue with a satellite dwell and thus stable pointing period.
- RIMO [HFI meaning]: The RIMO, or Reduced Instrument Model is a FITS file containing selected instrument characteristics that are needed by users who work with the released data products.
- ROI : Ring-Ordered Information (DMC group/object)
- rpm : revolutions per minute
- RSSD : Research Space Science Division of ESA [ESTEC, Netherlands]
- S/C : Spacecraft
- SAA : Solar Aspect Angle
- sample [HFI meaning]
- scanning beam [HFI meaning]: the scanning is defined as the beam measured from the response to a point source of the full optical and electronic system, after the filtering.
- scanning beam [LFI meaning]: the actual beam which couples the optics of the instrument with the scanning movement of the satellite (beam smearing). It can be measured from planet observations.
- SCS : Sorption Cooler Subsystem (Planck)
- SEV : Sun Earth Vector
- SGR : Small Gap Recovery
- SGS : Science Ground Segment
- SIAM : Spacecraft Instrument Alignment Matrix
- SOVT : System Operation and Validation Test
- spectral response (or bandpass): steady state response of a detector system (i.e., detector and its electronics + horn + filter) as a function of frequency. It does not consider the temporal response and associated transfer function.
- SPPT : Survey Performance and Planning Tool
- SREM : Space Radiation Environment Monitor
- SRP : Solar Radiation Pressure
- SSCE : Sun-SpaceCraft-Earth angle max= 15°
- SSO : Solar System Object
- STR : Star TRacker
- survey [HFI meaning]: sky surveys (aka Scan #)are defined in terms of the direction of the satellite's spin axis. Survey periods are given here.
- SVM : Service Module
- SZ : Sunyaev-Zel'dovich effect
- TBC : To Be Confirmed
- TBD : To Be Determined
- TC : Tele-Command
- THF : Telecommand History File
- TOD [HFI meaning]: Time-Ordered Data
- TOD [LFI meaning]: Time-Ordered Data, refers to calibrated data
- TOI [HFI meaning]: Time Ordered Information
- TOI [LFI meaning]: Time Ordered Information, refers to uncalibrated data
- ToS : Time of Sample
- UTC : Universal Time Coordinate(d)
- warm units : JFET, Bellow, PAU et REU
- WHR : Weekly Health Report
Attitude Control & Measurement Subsystem (AOCS)
Attitude History File
Application Program Identifier
Augmented Preprogrammed Pointing List
[LFI meaning]: absolute calibration refers to the 0th order calibration for each channel, 1 single number, while the relative calibration refers to the component of the calibration that varies pointing period by pointing period.
(Planck) High Frequency Instrument
(Planck) Low Frequency Instrument
LFI warm electronics Back End Module
Command and Data Management System
Command and Data Management Unit
Cosmic Microwave background
Commissioning Phase
Central Time Reference
CCSDS Unsegmented Time Code
Dilution Cooler Electronics
MOC's Data Distribution System
[ESA's] Mission Operation Center [Darmstadt, Germany]
Data Management Component, the databases used at the HFI and LFI DPCs
Data Processing Center
Data Processing Unit
Daily Quality Report
Daily Tele-Communication Period
End Of Life
Early Release Compact Source Catalog
European Space Agency
European Space Operations Centre (Darmstadt)
European Space TEchnology and Research Centre
LFI cryogenic amplifying stage Front End Module
Flexible Image Transfer Specification
Fiber Optic Gyroscope
Field-Of-View
Focal Plane Unit
Full-Width-at-Half-Maximum
difference between the map built using the first half of each pointing period (typically 20 minutes of contiguous data) and the one built with the second half. This difference effectively removes the sky signal and most of the correlated noise, leaving only the noise components that have time scales of < ~ 20 min.
Angular momentum Control Mode
High Electron Mobility Transistor
Herschel/Planck File Transfer System
Herschel/Planck Mission Control System
(Hierarchical Equal Area isoLatitude Pixelation of a sphere, <ref name="Template:Gorski2005">HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere, K. M. Górski, E. Hivon, A. J. Banday, B. D. Wandelt, F. K. Hansen, M. Reinecke, M. Bartelmann, ApJ, 622, 759-771, (2005).
House-Keeping data
Interface Control Document
reduced IMO
Instrument Operation Team
Junction Field Elect Transistor
Launch & Early Orbit Phase
Local On Board Time
Line Of Sight
Noise Equivalent Temperature
On-Board Time
Operation Day definition is geometric visibility driven as it runs from the start of a DTCP (satellite Acquisition Of Signal) to the start of the next DTCP. Given the different ground stations and spacecraft will takes which station for how long, the OD duration varies but it is basically once a day.
Payload
Pre_Amplification Unit
Principal Investigator
Planck Legacy Archive
Payload Module
Physical Optics
Phase-Ordered Information (DMC group/object)
Pre-programmed Pointing List
Planck Payload Module
Planck Sky Model
Planck Science Office
Physical Theory of Diffraction
Packet Utilisation Standard
Raw Attitude history File
LFI Radiometer Electronics Box Assembly
Readout Electronic Unit
Radio Frequency Qualification Model
Ring-Ordered Information (DMC group/object)
revolutions per minute
Research Space Science Division of ESA [ESTEC, Netherlands]
Spacecraft
Solar Aspect Angle
Sorption Cooler Subsystem (Planck)
Sun Earth Vector
Small Gap Recovery
Science Ground Segment
Spacecraft Instrument Alignment Matrix
System Operation and Validation Test
Survey Performance and Planning Tool
Space Radiation Environment Monitor
Solar Radiation Pressure
Sun-SpaceCraft-Earth angle max= 15°
Solar System Object
Star TRacker
Service Module
Sunyaev-Zel'dovich
To be confirmed
To be defined / determined
Tele-Command
Telecommand History File
Time of Sample
Universal Time Coordinate(d)
JFET, Bellow, PAU et REU
JFET, Bellow, PAU et REU
Weekly Health Report