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information_for_astronomers:user_guide:faq
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information_for_astronomers:user_guide:faq [2014/03/19 14:08] bwinkel [Preparation] |
information_for_astronomers:user_guide:faq [2014/12/11 08:22] bwinkel [Previewing the data] |
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| === How can I have a look into my spectral data, to check if everything is ok? === | === How can I have a look into my spectral data, to check if everything is ok? === | ||
| - | Again, you could use the [[information_for_astronomers:user_guide:pyonlplot|Online Plotter]] for a preview, but most people will prefer to use ''Gildas/Class'' for this task. Our class pipeline runs on ''observer5'', so for a timely access log-in to this machine. Files will be located in ''/data/Class''. See [[information_for_astronomers:user_guide:reduction_of_spectroscopic_measurements|this page]] for details. | + | Again, you could use the [[information_for_astronomers:user_guide:pyonlplot|Online Plotter]] for a preview, but most people will prefer to use ''Gildas/Class'' for this task. Our class pipeline runs on ''observer2'' and ''observer4'', so for a timely access log-in to this machine. Files will be located in ''/data/Class''. See [[information_for_astronomers:user_guide:reduction_of_spectroscopic_measurements|"reduction of spectroscopic measurements"]] for details. |
| ===== Obtaining the data ===== | ===== Obtaining the data ===== | ||
| === Where is the data stored? === | === Where is the data stored? === | ||
| - | Raw data files (in FITS format) are originally stored in ''/daten/Raw'' on ''be4'', but this directory is NFS-mounted on most user machines (e.g., ''observer2'' and ''observer5''. The latter runs the ''Class'' pipeline to produce the spectroscopy files in ''Gildas'' format. So, if you only want these, you should use ''observer5'' to read the data located in ''/daten/Class''. | + | Raw data files (in FITS format) are originally stored in ''/daten/Raw'' on ''be4'', but this directory is NFS-mounted on most user machines (e.g., ''observer2'' and ''observer4''. The latter runs the ''Class'' pipeline to produce the spectroscopy files in ''Gildas'' format. So, if you only want these, you should use ''observer4'' to read the data located in ''/daten/Class''. |
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| + | [[information_for_astronomers:user_guide:data_storage_and_archive]] | ||
| === How do I copy them to my place? === | === How do I copy them to my place? === | ||
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| ===== Calibrating and analyzing the data ===== | ===== Calibrating and analyzing the data ===== | ||
| === What steps are necessary to calibrate my data? === | === What steps are necessary to calibrate my data? === | ||
| - | The FITS files contain the Raw data (pure counts), while the "reduced" spectra and continuum scans contained in the ''Class'' files were in fact only partly calibrated by the pipeline. In fact, the pipeline removes the gain factor ("bandpass") from the data using the position-switch or frequency-switch technique, but the result is in units of the noise diode's signal, $T_\mathrm{cal}$. You have to use calibration sources to measure $T_\mathrm{cal}$. For quick'n'dirty calibration you can use values from our [[information_for_astronomers:rx_list|RX list]]. Furthermore, depending on observing frequency you will need to correct for elevation-dependent gain efficiency and atmospheric opacity. Details are discussed a calibration memo by A. Kraus (on request) and partly in [[http://adsabs.harvard.edu/abs/2012arXiv1203.0741W| A&A 540, A140, 2012]]. | + | The FITS files contain the Raw data (pure counts), while the "reduced" spectra and continuum scans contained in the ''Class'' files are only partly calibrated by the pipeline. In fact, the pipeline removes the gain factor ("bandpass") from the data using the position-switch or frequency-switch technique, but the result is in units of the noise diode's signal, $T_\mathrm{cal}$. You have to use calibration sources to measure $T_\mathrm{cal}$. For quick'n'dirty calibration you can use values from our [[information_for_astronomers:rx_list|RX list]]. Furthermore, depending on observing frequency you will need to correct for elevation-dependent gain efficiency and atmospheric opacity. Details are discussed in a calibration memo by A. Kraus (on request) and partly in [[http://adsabs.harvard.edu/abs/2012arXiv1203.0741W| A&A 540, A140, 2012]]. |
information_for_astronomers/user_guide/faq.txt · Last modified: 2019/08/10 21:54 by akraus
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