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EIS Data Analysis Userguide
Quick links:How do I get my hands on the data?
How do I do cosmic ray removal
The EIS data analysis software package will hopefully be a joint effort where scientist using EIS data and developing useful software share their contributions through SolarSoft (SSW). The EIS team will provide software to calibrate data and access the data easily, and from thre on, each and everyone is basically free to do whatever they may please with the data.
How do I get my hands on the data
The easiest way of accessing data in a file called "mydatafile" is through the IDL procedure called eis_getdata:
SSWIDL> eis_getdata, myfilename, wd, (iwin = iwin, /all, hdr = hdr, /ccsds)
The inputs parameters are:
The output parameters are:
The keyword parameters (optional) are:
Example1: The data file myfilename is a FITS file containing a scanning raster with 200 raster positions, 512 pixels along the slit, 25 line windows each of 32 pixels width. Return line windows 3, 12 and 24. I also want the FITS header.
SSWIDL>eis_getdata, myfilename, wd, iwin=[3,12,24], hdr = hdr.
The wd cube should now have dimensions: [32, 512, 200, 3] or [nlambda, nslit, nraster, nlines].
Example2: The data file myfilename is a `CCSDS file containing a full CCD exposure. 512 pixels along the slit, 4 line windows each of 1024 pixels width. Return all line windows. I also want the telemetry header
SSWIDL>eis_getdata, myfilename, wd, /all, hdr = hdr, /ccsds
The wd cube should now have dimensions: [1024, 512, 1, 4] or [nlambda, nslit, nraster, nlines].
I want to calculate velocities, widths etc. How?There are two ways of calculating intensity, velocity and width from the line profiles. It can either be done from the QL control window XCONTROL, by clicking the "moments" button, or it can be done using a procedure called "eis_getmoments". In the first case, results are displayed using the QL, in the latter, the user will get hands on access to the calculated quantities.
In both cases, the user need to manually interact in order to define line and continuum pixels. In the future this could be done automatically from e.g. line IDs, but o far the logic around this has not been worked out. Input from the planning tool may be needed, and we're not there yet.
The usage of eis_getmoments is decribed in what follows:
SSWIDL> eis_getmoments, file, int, vel, wid, iwin =iwin, all = all, gauss = gauss, $ moment = moment, ccsds = ccsds, lamtype = lamtype, $ line_def = line_def
example 1: Calculate int, vel wid, from Line window 0 from CCSDS file1= 'file1.dat':
SSWIDL> eis_getmoments, file1, int,vel,wid, iwin=0, /ccsds
example 2: Get line windows 2 and 3 from fitsfile file2='file2.fits'. Use wavelength scale and gaussian fits:
IDL> eis_getmoments, file2,int,vel, wid, iwin=[2,3], lamtype='wav', /gauss
How do I do Cosmic Ray Removal
There is a routine called "eis_despike.pro" to do cosmic ray removal for one line window and on eexposure. So far there is now script available to process many line windows and several exposures automatically. eis_despike is based on the SSW procedure called "new_spike.pro", which has been extensively used and tested on CDS data.
To do cosmic ray removal do:
SSWIDL> eis_despike, wd_in, wd_despike
For description of keywords, see documentation of new_spike.pro in SSW.
I want to make a movie from several rasters. How?
Updated 11-May-2006 by Øivind Wikstøl