Difference between revisions of "Terminology"

From Planck Legacy Archive Wiki
Jump to: navigation, search
Line 1: Line 1:
 +
;JT: Jan Tauber.
 
;4K lines: EMI/EMC influence of the 4K cooler mechanical motion on the bolometer readout electronics.
 
;4K lines: EMI/EMC influence of the 4K cooler mechanical motion on the bolometer readout electronics.
 
;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 [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.

Revision as of 09:31, 2 February 2018

JT
Jan Tauber.
4K lines
EMI/EMC influence of the 4K cooler mechanical motion on the bolometer readout electronics.
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.
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.
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.
far sidelobe [HFI meaning]
the response to the sky of a detector more than 5 degrees from the beam centroid.
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.
HEALPix
(Hierarchical Equal Area isoLatitude Pixelation of a sphere, [1]) pixelation used to produce Planck sky maps (and HFI HPR).
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. HPR are therefore partial sky maps produced via a projection onto the sky of each single pointing period separately.
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.
jump 
sudden change of the baseline level inside a ring
main beam [HFI meaning]
Response to the sky within 23 arcminutes of the centroid of response.
near sidelobe [HFI meaning]
Response to the sky between 23 arcminutes and 5 degrees from the main beam centroid.
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]
The response to the sky due to optics alone.
PBR [HFI meaning]
Phase Bin Rings provide a compressed and higher signal-to-noise ratio rendition of the original Time Order Data
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.
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.
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.
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.
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.
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
warm units 
JFET, Bellow, PAU et REU
ACMS 
Attitude Control & Measurement Subsystem (AOCS)
ADC 
analog to digital converter
AHF 
Attitude History File
APID 
Application Program Identifier
APPL  
Augmented Preprogrammed Pointing List
BEM 
LFI warm electronics Back End Module
BEU 
LFI warm electronics Back End Unit
BTB 
Back To Back HFI horns
CDMS 
Command and Data Management System
CDMU 
Command and Data Management Unit
CMB 
Cosmic Microwave background
CoP 
Commissioning Phase
CPV 
Calibration and Performance Verification
CSL 
Centre Spatial de Liège
CTR 
Central Time Reference
CUC 
CCSDS Unsegmented Time Code
DAE 
LFI Data Acquisition Electronics
DCE 
Dilution Cooler Electronics
DDS 
MOC's Data Distribution System
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
EOL 
End Of Life
ERCSC 
Early Release Compact Source Catalog
ES 
Explanatory Supplement
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
FEU 
LFI cryogenic amplifying stage Front End Unit
FH 
Feed Horn
FITS  
Flexible Image Transfer Specification
FOG 
Fiber Optic Gyroscope
FOV 
Field-Of-View
FPU 
Focal Plane Unit
FWHM  
Full-Width-at-Half-Maximum
HCM 
Angular momentum Control Mode
HEMT 
High Electron Mobility Transistor
HFI 
(Planck) High Frequency Instrument
HK 
House Keeping
HPFTS 
Herschel/Planck File Transfer System
HPMCS 
Herschel/Planck Mission Control System
HSK 
House-Keeping data
ICD 
Interface Control Document
ILS 
Instrument Line Shape
IOT 
Instrument Operation Team
JFET 
Junction Field Elect Transistor
LEOP 
Launch & Early Orbit Phase
LFER 
low frequency excess response
LFI 
(Planck) Low Frequency Instrument
LOBT 
Local On Board Time
LOS 
Line Of Sight
MOC 
[ESA's] Mission Operation Center [Darmstadt, Germany]
NEP  
Noise Equivalent Power
NET  
Noise Equivalent Temperature
OBT  
On-Board Time
OMT 
LFI Ortho Module Transducer
P/L 
Payload
PAU 
Pre_Amplification Unit
PI 
Principal Investigator
PIA 
Planck Internal Archive
PLA  
Planck Legacy Archive
PLM 
Payload Module
PO 
Physical Optics
POI 
Phase-Ordered Information (DMC group/object)
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
RAA 
LFI Radiometer Array Assembly
RAF 
Raw Attitude history File
RCA 
LFI Radiometer Chain Assembly
REBA 
LFI Radiometer Electronics Box Assembly
REU 
Readout Electronic Unit
RFQM 
Radio Frequency Qualification Model
RIMO 
reduced IMO
ROI 
Ring-Ordered Information (DMC group/object)
rpm 
revolutions per minute
RSSD 
Research Space Science Division of ESA [ESTEC, Netherlands]
RTS 
random telegraphic signal
S/C 
Spacecraft
SAA 
Solar Aspect Angle
SCC 
Sorption Cooler Compressor assembly
SCS 
Sorption Cooler Subsystem (Planck)
SEV  
Sun Earth Vector
SGR  
Small Gap Recovery
SGS  
Science Ground Segment
SIAM  
Spacecraft Instrument Alignment Matrix
SLT 
System Level Test
SOVT  
System Operation and Validation Test
SPPT 
Survey Performance and Planning Tool
SPU 
Signal Processing Unit
SREM 
Space Radiation Environment Monitor
SRP  
Solar Radiation Pressure
SSCE 
Sun-SpaceCraft-Earth angle max= 15°
SSO 
Solar System Object
STR  
Star TRacker
SVM 
Service Module
SZ  
Sunyaev-Zel'dovich
TBC 
To be confirmed
TBD 
To be defined / determined
TC 
Tele-Command
THF 
Telecommand History File
ToS 
Time of Sample
TSA 
hermal Stabilization Assembly
UTC 
Universal Time Coordinate(d)
warm units 
JFET, Bellow, PAU et REU
WG 
LFI Waveguide
WHR 
Weekly Health Report

References[edit]

  1. 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).

EMI/EMC influence of the 4K cooler mechanical motion on the bolometer readout electronics.

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.

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.

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.

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.

the response to the sky of a detector more than 5 degrees from the beam centroid.

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.

(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).

(Planck) High Frequency Instrument

HEALPix Rings are introduced to avoid any additional binning of the data. We choose a sky pixelization as a basis for this ring making. HPR are therefore partial sky maps produced via a projection onto the sky of each single pointing period separately.

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.

Data Processing Center

reduced IMO

sudden change of the baseline level inside a ring

Response to the sky within 23 arcminutes of the centroid of response.

Response to the sky between 23 arcminutes and 5 degrees from the main beam centroid.

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.

Daily Tele-Communication Period

The response to the sky due to optics alone.

Phase Bin Rings provide a compressed and higher signal-to-noise ratio rendition of the original Time Order Data

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.

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.

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.

Flexible Image Transfer Specification

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.

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.

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.

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.

sky surveys (aka Scan #)are defined in terms of the direction of the satellite's spin axis. Survey periods are given here.

Time-Ordered Data

Time-Ordered Data, refers to calibrated data

Time Ordered Information

Time Ordered Information, refers to uncalibrated data

JFET, Bellow, PAU et REU

JFET, Bellow, PAU et REU

Junction Field Elect Transistor

Pre_Amplification Unit

Readout Electronic Unit

Attitude Control & Measurement Subsystem (AOCS)

analog to digital converter

Attitude History File

Application Program Identifier

Augmented Preprogrammed Pointing List

LFI warm electronics Back End Module

(Planck) Low Frequency Instrument

LFI warm electronics Back End Unit

Back To Back HFI horns

Command and Data Management System

Command and Data Management Unit

Cosmic Microwave background

Commissioning Phase

Calibration and Performance Verification

Centre Spatial de Liège

Central Time Reference

CCSDS Unsegmented Time Code

LFI Data Acquisition Electronics

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 Unit

Daily Quality Report

End Of Life

Early Release Compact Source Catalog

Explanatory Supplement

European Space Agency

European Space Operations Centre (Darmstadt)

European Space TEchnology and Research Centre

LFI cryogenic amplifying stage Front End Module

LFI cryogenic amplifying stage Front End Unit

Feed Horn

Fiber Optic Gyroscope

Field-Of-View

Focal Plane Unit

Full-Width-at-Half-Maximum

Angular momentum Control Mode

High Electron Mobility Transistor

House Keeping

Herschel/Planck File Transfer System

Herschel/Planck Mission Control System

House-Keeping data

Interface Control Document

Instrument Line Shape

Instrument Operation Team

Launch & Early Orbit Phase

low frequency excess response

Local On Board Time

Line Of Sight

Noise Equivalent Power

Noise Equivalent Temperature

On-Board Time

LFI Ortho Module Transducer

Payload

Principal Investigator

Planck Internal Archive

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

LFI Radiometer Array Assembly

Raw Attitude history File

LFI Radiometer Chain Assembly

LFI Radiometer Electronics Box Assembly

Radio Frequency Qualification Model

Ring-Ordered Information (DMC group/object)

revolutions per minute

Research Space Science Division of ESA [ESTEC, Netherlands]

random telegraphic signal

Spacecraft

Solar Aspect Angle

Sorption Cooler Compressor assembly

Sorption Cooler Subsystem (Planck)

Sun Earth Vector

Small Gap Recovery

Science Ground Segment

Spacecraft Instrument Alignment Matrix

System Level Test

System Operation and Validation Test

Survey Performance and Planning Tool

Signal Processing Unit

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

hermal Stabilization Assembly

Universal Time Coordinate(d)

LFI Waveguide

Weekly Health Report