Community Release Note for SPIRE Calibration 9_1
The SPIRE calibration tree "spire_cal_9_1" was released in July 2012 to be compatible with HIPE v9.0.
Note that this calibration tree corrects a problem found in the "pre-release" tree, 9_0, with the PhotChanNoise product. The noise level for PLWD2 was corrected (note that small changes are also present for all other detectors too).
Impact of the changes compared to the previous release (8_1)
- The photometer filter profiles are contained in SCalPhotRsrf. This will add a frequency column to match Spectrometer data which are now in frequency and not wavenumber. Only affects IA.
- The electrical crosstalk updates mean that the electrical crosstalk correction can be included in the SPG pipeline. These crosstalk files should change the thermistor timelines but not the bolometer timelines.
- The PCAL profile will allow the SPG pipeline to use the new PCAL processing algorthm that takes the PCAL baseline into account. This fills the photPcal product which is just for information (it does not affect data in the photometer pipeline).
- Update the SCalPhotChanNoise to correct for PLWD2 white noise, which was too high because of an outlier not rejected by the RobustMean in the previous derivation.
- Fixing units in the bright gain file means that correct units can be propagated by the task in the pipeline. Affects bright mode observations only.
- The nominal PCAL values needed to be updated to match the new PCAL processing algorithm. Affects bright mode observations only.
- Updating the beamParam product will
- allow using the new Uranus model - small effect on the pipeline result, but model better justified. Biggest effect at longest wavelength.
- include off-axis point source conversion. No effect on SPG pipeline. For information and IA only.
- restructure product to remove unnecessary columns and include errors. Makes it easier to understand for IA (no change to pipeline)
- The PCAL profile will allow the SPG pipeline to use the new PCAL processing algorthm that takes the PCAL baseline into account. This is used for processing of bright mode observations only and leads to an improved PCAL gain esp. for very bright sources.
- The beam prof product is not used in the pipeline - purely informational. Currently has pre-launch model data. Resetting to NaN makes it clear that this should not be used. Update planned for v10.
- Errors for smecStepFactor are purely informational and not used by the pipeline.
- Errors for bolPhase are purely informational and not used by the pipeline.
- RSRF files must be updated to match software updates in the pipeline - this makes them consistent with the final pipeline.
- The RSRF and beamParam for LR mode are now created only from LR data, giving a better shape to processed low resolution data.
- The new teleModel allows a correction to be made to the telescope model and leads to a substantial improvement in data for faint sources.
- Changing the OPD limits is necessary for the new phase correction algorithm, and also for consistency to include the real limits for CR observations. CR observations are now processed as HR within the pipeline rather than relying on setting the values in the opdLimits product.
Differences in individual products compared to the previous release
For detailed information about each product, see http://herschel.esac.esa.int/twiki/bin/view/Public/SpireCalibrationProducts.
- SCalPhotRsrf: Column containing frequency in GHz added (previously only contained wavenumber).
- SCalPhotElecCross: Electrical crosstalk coefficients introduced for bolometer-thermistor crosstalk.
- SCalPhotPcalModel: New product to contain a model of the PCAL flash profile, used in fitting PCAL flashes.
- SCalPhotChanNoise: Correct noise for PLWD2 (note that small changes are also present for all other detectors too).
Release Date: July 2012 (coinciding with the public release of HIPE v9.0)
- SCalSpecBrightGain: Correction to units. No change to values.
- SCalSpecNomPcal: Updated to match results from improved PCAL task.
- SCalSpecBeamParam: Updated calibration to use new Uranus model, updated beam FWHM and improved LR calibration (+include point source calibration for off-axis detectors and remove forwardRsrf and reverseRsrf columns).
- SCalSpecPcalModel: New product to contain a model of the PCAL flash profile, used in fitting PCAL flashes.
- SCalSpecBeamProf: Set all values to NaN until measured values can be added (previously was pre-launch model which should not be used).
- SCalSpecSmecStepFactor: Add errors. No change to values.
- SCalSpecInstRsrf: Updated for v9 pipeline, and improvements for LR products.
- SCalSpecTeleRsrf: Updated for v9 pipeline, and improvements for LR products.
- SCalSpecOpdLimits: Revert CR limits back to the true limits (CR was set equal to HR in v8_1).
- SCalSpecTeleModel: New product to contain telescope model correction coefficients.
- SCalSpecBolPhase: Add errors. No change to values.