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Revision 1092014-03-17 - IvanV

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SPIRE instrument and calibration web pages

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 This page provides up-to-date information about using the SPIRE instrument: from preparing observations to reducing your data. This page also provides you with the latest calibration accuracies and known SPIRE calibration issues.
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Observing with SPIRE

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Documents explaining SPIRE

 
<--The most up to date information on instrument calibration and performance is given in the SPIRE Observers' Manual. This is the reference document used by all the rest of the SPIRE user guides (eg data reduction guide, cookbooks etc). Sometimes it may happen that outdated values are quoted in some of the documents. In such a case use the values given in the SPIRE Observers' Manual. -->
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  • Summary papers from the A&A Special Issue:
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  • Summary papers from the A&A Special Issue, volume 518 (2010):
 
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    • 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.

  • 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 as a plug-in for HIPE. 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

The SPIRE Launch Pads

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  • The SPIRE Launch Pads are single sheet quick entries (like a cheat sheet) into SPIRE data reduction and providing quick references to the relevant sections in the SPIRE Data Reduction Guide. There are launch pads for Data Access, SPIRE Photometer and Spectrometer data reduction.
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  • The SPIRE Launch Pads are single sheet quick entries (like a cheat sheet) into SPIRE data reduction and providing quick references to the relevant sections in the SPIRE Data Reduction Guide. There are launch pads for Data Access, SPIRE Photometer and Spectrometer data reduction.
 
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Spectrometer data reduction

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Known Issues in ODs 1304 & 1305

For (yet) unknown reasons, the three detectors PSW-B5, PSW-E9 and PSW-F8 - that use to behave well during the entire mission - were noisy during the two operational days 1304 and 1305. The result are stripes visible in the final PSW map which the current (HIPE 11) pipeline is not able to correct. The solution is to mask and exclude these detectors from the analysis. This could be done in 2 ways:

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  1. You can use the SpireMaskEditor GUI as described in sec. 7.4.2 of the SPIRE Data Reduction Guide: write-click on your observation context variable and then select Level1_SpireMaskEditor and set to Master all samples in all scans (listed as BBID) for the detectors mentioned above.
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  1. You can use the SpireMaskEditor GUI as described in Sec. 8.4 of the SPIRE Data Reduction Guide: write-click on your observation context variable and then select Level1_SpireMaskEditor and set to Master all samples in all scans (listed as BBID) for the detectors mentioned above.
 
  1. Alternatively, you can use these lines of code

  • After either of those cases, you must then re-run level 1 to 2 steps on the newly modified level1 product. If your observation has been already re-reduced with HIPE 11, original and new level1s are already destriped, so you can directly run the naive map-maker on the new level1. Otherwise, you must run the destriper step: check the pipeline script for details.
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Planck-HFI & Herschel-SPIRE cross calibration: absolute offset re-processing

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Herschel-SPIRE detectors are only sensitive to relative variations, and so as a consequence, the absolute brightness of the observed region is unknown and maps are constructed such that they have zero median. The Planck-HFI detectors are similar to the SPIRE ones, but the Planck observing strategy allowed it to (almost) observe a great circle on the sky every minute (having a 1 rpm spinning rate). By comparing the sky brightness as measured by COBE-FIRAS at the galactic poles (where the dust emission is lower), HFI is capable of setting an absolute offset to its maps. SPIRE and HFI share two channels with overlapping wavebands: SPIRE-PMW and HFI-857 have a similar filter profile, while SPIRE-PLW and HFI-545 are shifted by ~10%.
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As of HCSS 11, a new task named zeroPointCorrection is available to the users: this task calculates the absolute offset for a SPIRE map based on cross-calibration with HFI-545 and HFI-857 maps, colour-correcting HFI to SPIRE wavebands assuming a grey body function with fixed beta.
 
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As of HCSS 11, a new task named zeroPointCorrection is available to the users: this task calculates the absolute offset for a SPIRE map based on cross-calibration with HFI-545 and HFI-857 maps, colour-correcting HFI to SPIRE wavebands assuming a grey body function with fixed beta. To run the task, you will need to download the 2 Planck maps HFI-545 and HFI-857 maps from the HSC/SPIRE FTP area as they are not included in the HIPE distribution. These maps are derived from the ones available in the Planck Legacy Archive, but convolved with an 8 arcmin Gaussian beam in order to circularize the effective map beams, plus the maps absolute offset as estimated by the Planck-HFI team via cross-calibration with FIRAS (see Planck Collaboration VIII. 2013, In preparation)
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Details on how to run the task are available in the SPIRE Data Reduction Guide, Section 6.8
 
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The offsets are computed on extdPxW maps, calibrated for extended emission, with extended gain correction applied and in units of MJy/sr (as explained in the section 4.10 of the SPIRE Data Reduction Guide). Hence, the re-processing will start from a level-1 context (which may be the result of merging multiple observations, see e.g. the Photometry Map Merging scirpt available in HIPE under the menu ScriptsSPIRE Useful script) and then executing the zeroPointCorrection task with one of the following methods:
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<-- Herschel-SPIRE detectors are only sensitive to relative variations, and so as a consequence, the absolute brightness of the observed region is unknown and maps are constructed such that they have zero median. The Planck-HFI detectors are similar to the SPIRE ones, but the Planck observing strategy allowed it to (almost) observe a great circle on the sky every minute (having a 1 rpm spinning rate). By comparing the sky brightness as measured by COBE-FIRAS at the galactic poles (where the dust emission is lower), HFI is capable of setting an absolute offset to its maps. SPIRE and HFI share two channels with overlapping wavebands: SPIRE-PMW and HFI-857 have a similar filter profile, while SPIRE-PLW and HFI-545 are shifted by ~10%.
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<-- To run the task, you will need to download the 2 Planck maps HFI-545 and HFI-857 maps from the HSC/SPIRE FTP area as they are not included in the HIPE distribution. These maps are derived from the ones available in the Planck Legacy Archive, but convolved with an 8 arcmin Gaussian beam in order to circularize the effective map beams, plus the maps absolute offset as estimated by the Planck-HFI team via cross-calibration with FIRAS (see Planck Collaboration VIII. 2013, In preparation)
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