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Eis_prep
Eis_prep

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At line 1 added 2 lines
[{ALLOW edit EISMainUsers}]
[{ALLOW view Anonymous}]
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The standard way of calling eis_prep is:
IDL> eis_prep, filename, /default, /save
which will create the level-1 FITS file and associated error FITS file in the working directory. Additional keywords that you may want to use are:
/quiet - eis_prep runs without popping up information widgets
/retain - see Step 2 discussion below
/noabs - calibration is not performed (Step 6 below), so the final units are DN
/photons - instead of erg/cm2/s/sr/Angstrom, the final units will be photons/cm2/s/sr/Angstrom
The full list of keywords is given in the header of the eis_prep routine.
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It is to be noted that both of these methods will yield some pixels with negative DN values. For window data it will only be 1 % of pixels because of the method used, but for full CCD spectra it can be up to 50 % of pixels if the raster contains very weak emission (e.g., coronal holes or off-limb spectra). ''The default mode for eis_prep sets pixels with zero or negative DN values to be missing data.'' This is because it is not possible to assign a photon noise error to the data points.
It is to be noted that both of these methods will yield some pixels with negative DN values. For window data it will only be 1 % of pixels because of the method used, but for full CCD spectra it can be up to 50 % of pixels if the raster contains very weak emission (e.g., coronal holes or off-limb spectra). ''The default mode for eis_prep sets pixels with zero or negative DN values to be missing data.'' This is because it is not possible to assign a photon noise error to the data points. (Note that negative DN values are expected since, if there are zero solar counts, then the uncertainty in the CCD counts will be 0 +/- read noise.)
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Spectrometer (CDS) data-sets (Thompson et al., 1998; Pike
& Harrison, 2000). For CDS data processing it was typical
Spectrometer (CDS) data-sets ([Thompson et al., 1998|http://solar.bnsc.rl.ac.uk/swnotes/cds_swnote_46.pdf]; [Pike
& Harrison, 2000|http://adsabs.harvard.edu/abs/2000A%26A...362L..21P]). For CDS data processing it was typical
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with an error estimate of the dark current of 2.5 DN.
with an error estimate for the dark current. This varies from 2.24 to 2.37 DN for the four CCD quadrants.
This page (revision-7) was last changed on 07-Dec-2016 14:14 by PeterYoungTop