28 February 2013, 14:30 CET
Chair: Luca Conversi (HSC/ESA)

On the call: Allison Noble, Gabriele Mainetti, Simone Bianchi, Luca Conversi, Nicola Schneider, Karin Dassas, Chris Pearson, Stephan Ott, Bruno MerĂ­n

Video recording of the webinar




Contents:

- Minute 0:00: Presentation New improvements in HIPE 10 SPIRE photometer pipeline

- Minute 17:40: Q&A about timeline for Plank Data release an relation to SPIRE PHOT cross-calibration

- Minute 28:10: Presentation on Source Extraction and Photometry with SPIRE PHOT

- Minute 46:40: Demo on merging multiple observations and coverting maps to surface brightness

- Minute 1:06:00: Q&A about the structure of the multi-extension FITS files written by HIPE

- Minute 1:16:00: Q&A about how to use timelineFitter on merged maps

- Minute 1:18:20: Q&A about inclusion of old K4E/K4P factor in the convertImageUnit

- Minute 1:20:10: Demo on usage of bolometer finder to remove manually glitches from images

- Minute 1:31:54: end of video

Questions and Answers


Q - Nicola Schneider: How does the new map merging script treats saturated pixels?
A - Luca Conversi: Saturated pixels are automatically flagged in the level 0 to level 0.5 stage; they are then excluded from further calculation. When merging a second observation meant to recover saturated regions previously observed, the latter are automatically exluded and only the former are taken into account into the calculation.

Q - Allison Noble : does the convertImageUnit change also the error map? I wrote the output of that to a FITS file and the result did not look right. How do you load this in ds9? The ds9 command to open multi ext cube does not seem to work.
A - Luca Conversi: Yes, convertImageUnit changes the error map too. Although we were not able to reproduce it during the demo, we have checked afterwards that you can open the image with File -> Open Multi Ext Data Cube in Saoimage Ds9 versions 6.1.2 onwards and you will see all three planes in order (1: image, 2: error, 3: coverage). You can always check how to read FITS files produced by HIPE in other systems with the instructions at http://herschel.esac.esa.int/twiki/bin/view/Public/ExportingDataProducts.

Q - Allison: how do I merge together a lot of level2 contexts of maps and run the timelineFitter
A - Luca Conversi: timelineFitter works on level1s, so you need to merge them (not level2 -> maps). However note that if the total stream of data is large, the current (HIPE 10.x) timelineFitter is slow and may take much time (this mainly affects large and parallel mode maps). In such cases I suggest to use the SussexSourceExtractor which work on (merged) maps and would be much faster

Q - Simone Bianchi: does the convertion to MJy/sr takes into account the old K4E/K4P factor?
A - Luca Conversi: No. If you are observing a point source but you want to do aperture photometry on a SPIRE map, you need to take a point-source calibrated psrcPxW map and convert it to Jy/pixel or MJy/sr using the convertImageUnit task and the provided beam areas.
If you are interested in an extended source, then you either take the new extdPxW maps or (if these are not available because the observation has not been reprocessed with HIPE 10.x yet) you start from the point-source calibrated map, convert it to Jy/pixel or MJy/sr using the convertImageUnit task and the provided beam areas AND multiply by the K4E/K4P.



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