Difference: SpireCalibrationWeb (133 vs. 134)

Revision 1342015-12-14 - IvanV

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META TOPICPARENT name="WebHome"

SPIRE instrument and calibration web pages

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SPIRE Spectrometer

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  • We also provide access to the latest stable developer build (latest stable CIB).
    • Beware These developer builds do not undergo the same in-depth testing as the user releases do. The latest developer build can be found here.
      Info Please contact the Herschel helpdesk if you plan to use a developer build as there may be some additional information needed in order for you to properly make use of it.
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  • Within HIPE you can access all the SPIRE data reduction and HIPE-user documentation. The SPIRE Data Reduction Guide (SDRG) follows the user pipeline scripts and also explains the details of pipeline processing and data analysis. It is also available online here:
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  • Within HIPE you can access all the SPIRE data reduction and HIPE-user documentation. The SPIRE Data Reduction Guide (SDRG) follows the user pipeline scripts and also explains the details of pipeline processing and data analysis. It is also available online here:
 
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  • SPIA: The SPIRE Photometer Interactive Analysis (SPIA) package is available in HIPE (previously it was a plugin). SPIA provides a structured GUI based access to the more intricate parts of the scan map photometer pipeline for SPIRE without the immediate need to resort to scripts. More information can be found in the SDRG or on the SPIA web page * Info Note: A bug that renders two deglitchers in the task spiaLevel1 unusable was found only recently. We have prepared a quick fix that will work on a standard HIPE 12.1 installation. Please see the SPIA web page for more information.
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<--   * SPIA: The SPIRE Photometer Interactive Analysis (SPIA) package is available in HIPE (previously it was a plugin). SPIA provides a structured GUI based access to the more intricate parts of the scan map photometer pipeline for SPIRE without the immediate need to resort to scripts. More information can be found in the SDRG or on the SPIA web page
     * Info Note: A bug that renders two deglitchers in the task spiaLevel1 unusable was found only recently. We have prepared a quick fix that will work on a standard HIPE 12.1 installation. Please see the SPIA web page for more information. -->
 

The SPIRE Launch Pads

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Spectrometer Overview

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The best source of information for reducing SPIRE Spectrometer data is the SPIRE Data Reduction Guide available through the HIPE help. This runs through the User Pipeline scripts step by step, describes several other Useful Scripts, and offers advice for specific types of sources:
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The best source of information for reducing SPIRE Spectrometer data is the SPIRE Data Reduction Guide available through the HIPE help. This runs through the User Pipeline scripts step by step, describes several other Useful Scripts, and offers advice for specific types of sources:
 
  • Faint (<10 Jy) and medium (<100 Jy) strength sources
  • Bright sources (>500 Jy)
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SPIRE Calibration Tree (& release note) Release Date Applicable HIPE Version Comment
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SPIRE_CAL_13_1 Apr 2015 HIPE v13.0 Calibration tree currently used in operations
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SPIRE_CAL_14_2 Dec 2015 HIPE v14.0 Calibration tree currently used in operations
SPIRE_CAL_13_1 Apr 2015 HIPE v13.0 Calibration tree currently used in operations
 
SPIRE_CAL_12_3 May 2014 HIPE v12.1 Final v12 cal tree
SPIRE_CAL_12_2 March 2014 HIPE v12  
SPIRE_CAL_11_0 July 2013 HIPE v11 Final v11 cal tree
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  Details of individual calibration products can be found here.
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  • Any of the calibration trees can be retrieved in HIPE from the HSA using (e.g.) cal = spireCal(calTree="spire_cal_13_1") etc. The default (applicable to the HIPE version in use) can be obtained with cal = spireCal(calTree="spire_cal"). It can then be saved to a local pool right-clicking on the cal variable and then selecting from the context menu Send To -> Local Pool.
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  • Any of the calibration trees can be retrieved in HIPE from the HSA using (e.g.) cal = spireCal(calTree="spire_cal_14_2") etc. The default (applicable to the HIPE version in use) can be obtained with cal = spireCal(calTree="spire_cal"). It can then be saved to a local pool right-clicking on the cal variable and then selecting from the context menu Send To -> Local Pool.
 
  • Alternatively, the latest calibration tree for SPIRE can be obtained as a jar file from Latest calibration trees. Then, you have to possibilities to read and save:
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    1. The jar file can be load directly into HIPE with the command: cal = spireCal(jarFile="PATH_TO_FILE/spire_cal_13_1.jar"). To save it to a local pool, proceed as described above, right-clicking on the cal variable and then selecting from the context menu Send To -> Local Pool.
    2. The jar file can also be saved directly to a local pool without opening HIPE, running the following command in the terminal command line: cal_import PATH_TO_FILE/spire_cal_13_1.jar. Then, to load the calibration tree in HIPE, simply type: cal = spireCal(pool="spire_cal_13_1")
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    1. The jar file can be load directly into HIPE with the command: cal = spireCal(jarFile="PATH_TO_FILE/spire_cal_14_2.jar"). To save it to a local pool, proceed as described above, right-clicking on the cal variable and then selecting from the context menu Send To -> Local Pool.
    2. The jar file can also be saved directly to a local pool without opening HIPE, running the following command in the terminal command line: cal_import PATH_TO_FILE/spire_cal_14_2.jar. Then, to load the calibration tree in HIPE, simply type: cal = spireCal(pool="spire_cal_14_2")
  See the SPIRE Data Reduction Guide for more details.
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<--     * Additionally repeatability of measured photometry to flux densities >100mJy ~ 2% -->

  • SPIRE Photometer Beams:
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    • These are available in the SPIRE calibration context, at the standard map pixel size of (6,10,14) arcsec/pixel for (250,350,500) Ám bands, and can be accessed in HIPE after a calibration context has been loaded (see above).
    • A more detailed analysis of the SPIRE beam profile data was undertaken in 2012, leading to revised values for beam profile solid angles and derivation of a semi empirical wavelength dependent beam profile model. The results at a scale of 1 arcsec/pixel as well as the data needed for the model are available for download. A detailed description of the analysis is given as well.
    • NEW A final analysis of the SPIRE beam profiles was completed in Oct 2014, taking into account so called "shadow" observations that were taken after Neptune had moved away. This dramatically reduced the uncertainties in the beam profile solid angles to better than 1%. It also eliminated the need for a "static" part in the semi-empirical beam profile model. The results at a scale of 1 arcsec/pixel as well as the data needed for the model are available for download. A detailed description of the analysis is available too.
<--      * Tip, idea The observed beams at much finer scale of 1 arcsec/pixel, as well as the theoretical ones, are available from here . Please read the release note for more details. -->
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    • NEW A final analysis of the SPIRE beam profiles was completed in Oct 2014, taking into account so called "shadow" observations that were taken after Neptune had moved away. This dramatically reduced the uncertainties in the beam profile solid angles to better than 1%. It also eliminated the need for a "static" part in the semi-empirical beam profile model. The results at a scale of 1 arcsec/pixel as well as the data needed for the model are available for download. A detailed description of the analysis is available too.
    • These new beam maps and radial profiles are available also in the latest SPIRE calibration tree (BeamProf, RadialCorrBeam).

<--      * These are available in the SPIRE calibration context, at 1 arcsec/pixel as well as with the standard map pixel size of (6,10,14) arcsec/pixel for (250,350,500) Ám bands, and can be accessed in HIPE after a calibration context has been loaded (see above). 
    • A more detailed analysis of the SPIRE beam profile data was undertaken in 2012, leading to revised values for beam profile solid angles and derivation of a semi empirical wavelength dependent beam profile model. The results at a scale of 1 arcsec/pixel as well as the data needed for the model are available for download. A detailed description of the analysis is given as well. -->
 
  • SPIRE Photometer filter transmission curves:
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    • These are also available in the SPIRE calibration context (photRsrf) and can be accessed in HIPE after a calibration context has been loaded (See above).
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    • These are available in the SPIRE calibration context (photRsrf).
 
  • Neptune and Uranus models used for the SPIRE photometer flux calibration:
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    • The ESA2 models used up to HIPE v10 and spire_cal_10_1, are available here.
 
    • NEW The ESA4 models used from HIPE v11 and spire_cal_11_0, are available here.
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    • The ESA2 models used up to HIPE v10 and spire_cal_10_1, are available here.
 

Spectrometer calibration and uncertainties

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    • Calibration uncertainties, which should be included in addition to the statistical errors of any measurement from HIPE v11 onwards, are as follows:
      • Point sources observed on the centre detectors (SSWD4 and SLWC3): the measured repeatability is 6%, with the following contributions: (i) absolute systematic uncertainty in the models from comparison of Uranus and Neptune - determined to be ▒3%; (i) the statistical repeatability determined from observations of Uranus and Neptune, with pointing corrected - estimated at ▒1% (excluding the edges of the bands); (iii) the uncertainties in the instrument and telescope model, which lead to an additive continuum offset error of 0.4 Jy for SLW and 0.3 Jy for SSW and (iv) the effect of the Herschel APE.
      • Sparse observations of significantly extended sources:
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        • the absolute uncertainty in intensity for a reasonably bright, fully extended object, observed in the central detectors is, in theory, ▒1%, with the following contributions: (i) the systematic uncertainty in telescope model of 0.06%; (ii) the statistical repeatability estimated at ▒1% and (iii) an additive continuum offset of 3.4x10-20 W/m2/Hz/sr for SLW and 1.1x10-19 W/m2/Hz/sr for SSW.
        • In practice, truly extended sources tend to be faint and the uncertainty is therefore dominated by the additive offsets. When the source extent is larger than the main beam size, but not fully extended, or if there is structure inside the beam, then the uncertainties are dominated by the source-beam coupling ( see Wu et al. 2013 ) and are significantly greater than 1%.
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        • the conservative absolute uncertainty in intensity for a reasonably bright, fully extended object, observed in the central detectors is of the order of 10%, with the following contributions: (i) the systematic uncertainty in telescope model of 0.06%; (ii) the statistical repeatability estimated at ▒1% (iii) an additive continuum offset of 3.4x10-20 W/m2/Hz/sr for SLW and 1.1x10-19 W/m2/Hz/sr for SSW and (iv) far-field feehorn efficiency correction of the order of 10% (conservative).
        • When the source extent is larger than the main beam size, but not fully extended, or if there is structure inside the beam, then the uncertainties are dominated by the source-beam coupling ( see Wu et al. 2013 ) and are greater than ▒10%.
 
      • Mapping mode: the variations between detectors becomes important and the overall repeatability has been measured as ▒7% (see Benielli et al., 2014 for a full discussion of mapping mode observations). The off-axis detectors are less well calibrated, especially outside the unvignetted part of the field.

  • Uranus model used for the SPIRE FTS point-source flux calibration:
 
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