This page (revision-13) was last changed on 07-Dec-2016 14:14 by Peter Young

This page was created on 06-Jul-2007 13:51 by Harry Warren

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Version Date Modified Size Author Changes ... Change note
13 07-Dec-2016 14:14 6 KB Peter Young to previous
12 07-Apr-2011 16:27 6 KB PeterYoung to previous | to last
11 08-Jul-2010 21:01 5 KB PeterYoung to previous | to last
10 06-Nov-2008 16:34 4 KB PeterYoung to previous | to last
9 09-Jul-2007 12:53 3 KB Louise Harra to previous | to last
8 09-Jul-2007 12:12 3 KB Louise Harra to previous | to last Comment by Louise Harra
7 07-Jul-2007 12:51 3 KB David Pérez-Suárez to previous | to last
6 07-Jul-2007 12:49 3 KB David Pérez-Suárez to previous | to last
5 06-Jul-2007 14:04 2 KB Harry Warren to previous | to last
4 06-Jul-2007 14:03 2 KB Harry Warren to previous | to last
3 06-Jul-2007 14:02 1 KB Harry Warren to previous | to last
2 06-Jul-2007 13:55 1 KB Harry Warren to previous | to last
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EISGetWindata
EISGetWindata

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At line 1 changed 3 lines
[{ALLOW edit EISMainUsers}]
[{ALLOW view Anonymous}]
!!! EIS_GETWINDATA - a wrapper to the EIS objects
I just wanted to alert people to the fact that we've written a wrapper to the EIS objects that return the data as a structure. This may provide somewhat faster access to the data. Here's a quick example. If you wanted to read the Fe XII 195 data window from a file and plot it you could do this:
At line 5 removed 5 lines
The EIS data are stored in IDL objects, and all information about the data can be accessed through object methods. However, sometimes it is convenient for the user to dump a particular wavelength window to an IDL structure, together with useful information such as pointing coordinates, start time, exposure time, etc.
The routine that does this is called __eis_getwindata__ and an example of how to call it for the Fe XII 195 data window is given below.
At line 67 removed 2 lines
!! PLOT_EIS_RASTER - plotting data from eis_getwindata
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!!Operations on WINDATA structures
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There are a number of routines available for performing operations on WINDATA structures. The full set are listed in [EIS Software Note #21|ftp://sohoftp.nascom.nasa.gov/solarsoft/hinode/eis/doc/eis_notes/21_WINDATA/eis_swnote_21.pdf].
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!Spatial binning (EIS_BIN_WINDATA)
Sometimes it is useful to perform spatial binning on EIS data in order to improve photon statistics on the emission lines. The routine eis_bin_windata is available in Solarsoft which takes the output from eis_getwindata and performs binning in the X and/or Y directions while preserving the form of the eis_getwindata structure. Errors on the intensities at each of the binned pixels are correctly calculated.
The routine is called as, e.g.,
{{{
IDL> wd=eis_getwindata(l1name,195.12)
IDL> wdnew=eis_bin_windata(wd,xbin=2,ybin=2)
}}}
!Joining two WINDATA structures (EIS_JOIN_WINDATA)
Takes two WINDATA structures from a data-set and joins them in the wavelength dimension to produce a single, new WINDATA structure. This is most useful if the two WINDATAs are directly adjacent on the detector.
{{{
IDL> wd1=eis_getwindata(l1name,184.54)
IDL> wd2=eis_getwindata(l1name,185.12)
IDL> wd=eis_join_windata(wd1,wd2)
}}}
!Correcting data arrays for orbit variation and slit tilt (EIS_SHIFT_SPEC)
The wavelength scale for individual spatial pixels changes across the raster due to the thermally-induced, orbital drift of line centroids and the EIS slit tilt. The routine EIS_SHIFT_SPEC takes an array of wavelength corrections, and interpolates the intensity and error arrays such that the same wavelength scale applies to each spatial pixel. Due to complications of interpolating over missing pixels, the /refill option should be used in the call to eis_getwindata.
{{{
IDL> eis_wave_corr_hk, l1name, wvl_corr
IDL> wd=eis_getwindata(l1name, 195.12, /refill)
IDL> wd_new=eis_shift_spec(wd,wvl_corr)
}}}
!Trimming the wavelength range of a windata structure (EIS_TRIM_WINDATA)
This routine is intended for WINDATA structures with a large wavelength coverage; most commonly this will be full CCD data. An example use is when EIS_AUTO_FIT is to be run on just a single emission line within a full CCD spectrum. By trimming the wavelength coverage of WINDATA to just including the wavelength region around the line of interest, the spectrum becomes easier to fit. The usage is as follows for the case where Fe XII 195.12 is to be studied:
{{{
IDL> wd=eis_getwindata(l1name, 195.12, /refill)
IDL> wd195=eis_trim_windata(wd,[194.12,196.12])
}}}
Here a +/- 1 angstrom band around the line of interest is extracted.
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This page (revision-13) was last changed on 07-Dec-2016 14:14 by Peter YoungTop