GDLSSW004_en, EPS, MDI, and Trace

Notebook for using SSW (Solar Soft Ware) on GDL (GNU Data Language).



To confirm how SSW works on GDL, I try to make a figure previously made in IDL.

The following is the figure 3 of Yamamoto & Sakurai (2009, PASJ, 61, 75).

This JPG figure is made from the original EPS file via 'convert' command.

The event in this figure is a X10 flare in AR10486.

Plotted is a 1600 A image observed by TRACE, and red and blue contoures show positive and negative field strengths of MDI.

Subjects in this trying are 1) to read observed data (fits files), 2) to make map structures, and 3) to make EPS files.

MDI data and map structure

First, I try to read MDI data and to plot a map structure.

There is no error message in reading MDI data.

'mreadfits.pro' to read multiple FITS files also works.

However, contents of data may be incorrect.

As far as I remember, outside of the photosphere, values are the minimum value of FLOAT.

These values are 'nan.'


In making map structure, several messages appear.

% Compiled module: GET_FITS_CDELT.
% Compiled module: REP_TAG_NAME.
% Compiled module: IS_NUMBER.
% Compiled module: IS_NUMBER2.
% Input conversion error.
% Type conversion error: Unable to convert given STRING: 'cdel1' to FLOAT.
% Input conversion error.
% Type conversion error: Unable to convert given STRING: 'cdel2' to FLOAT.
% Input conversion error.
% Type conversion error: Unable to convert given STRING: 'dxb_img' to FLOAT.
% Input conversion error.
% Type conversion error: Unable to convert given STRING: 'dyb_img' to FLOAT.
% Compiled module: GET_FITS_CEN.

I checked procedures, and found that 'finite' function in is_number2.pro show these messages.

index2map.pro -> get_fits_par.pro -> get_fits_cdelt.pro -> rep_tag_name.pro -> is_number.pro -> is_number2.pro

These messages can be ignored.



After excluding 'nan' value, map structure is shown as follows.

The dynamic range is ±3000 G.



I exclude 'nan' as follows.

>    w0=where(finite(data0,/nan))
>    data0[w0]=-30000.





If one does not exclude 'nan' value from data, '0' value is overwritten there in plot_map_index.pro.

The following figure is a result of this.