TRACE, SXT, MDI, and SSW techniques

Created by freeland at Tue Feb 10 06:30:49 1999 at MEDOC;
Last revised by Bentley at MSSL, 5 September 2000.

SSW environment setup

 Include trace sxt mdi and eit (at least) in your SSW instrument list ($SSW_INSTR)

Find, read , and prep some trace images (L0->L1)

IDL> tracef=trace_files('04:00 1-jun-1998') ; Find the file

IDL> read_trace, tracef, -1, tindex ; Read all the image headers in 'tracef' -> tindex

IDL> filter=['naxis1=1024','wave_len=171']
IDL> ss=struct_where(tindex,test=filter) ; Select desired instrument parameters using struct_where

OR

IDL> ss=trace_sswhere(tindex) ; Select desired instrument parameters from the WIDGET
For this demo, select channel = 171, NX 1024, then push [SHOW SELECTION] button and [EXIT]

IDL> read_trace, tracef, ss, tindex, tdata ; read the filtered subset of data
NOTE - tindex is a vector of six "header structures" and tdata is 3D (1024x1024x6)

IDL> trace_prep, tindex, tdata, otindex, otdata, /wave2point_correct ; PREP the data w/defaults; apply wavelength dependendent pointing correction
(You may ignore all the 'information' dumped to your terminal)

Apply the Mapping software to the TRACE L1 data just created

IDL> stdata=bytscl(alog10(otdata>1)) ; (optional) scale the data

IDL> index2map, otindex, stdata,tmap ; make maps using scaled data
NOTE tmap contains 6 elements (maps)

IDL> plot_map, tmap(0), grid=15, xsize=1024 ; plot the FIRST map with a solar grid

IDL> oplot_nar, anytim(otindex(0),/ecs) ; show what NOAA Active Region you are looking at, just cause you can...

Play with plot_map

For example, parameters FOV (size in arcminutes of field) and CENTER (of FOV) coordinates in arcseconds [EW,NS] permit zooming in and out and changing center of field of view.

Do some coordinated analysis with this trace data

 IDL> mdif=mdi_files(otindex(0)) ; find nearest MDI file for first trace image

IDL> rd_mdi, mdif, mindex, mdata ; read mdi index,data

IDL> index2map, mindex, mdata, mdimap, ref_sub=tmap(0) ; make the corresponding mdi map using trace map as reference (index2map calls sub_map internally

IDL> plot_map, mdimap,/over,/rotate,/positive,lcolor=!p.color,drange=[-500,500] ; overplot rotated postitive polarity
IDL> plot_map, mdimap,/over,/rotate,/negative,lcolor=0,drange=[-500,500] ; overplot contours for rotated negative polarity

IDL> sxtf=yohkoh_files(otindex(0),/spr) ; find SXT partial frame image file closest to trace index

IDL> rd_xda,sxtf,-1,sindex ; read the image headers into sindex vector

IDL> ss=sswhere(sindex) ; select the image parameters of interest
For this demo, select NORMAL Mode exposure, SANDWICH (AlMg) filter and DPE = 24 (exposure duration). Then push SELECT and EXIT.

IDL> rd_xda, sxtf, ss, sindex, sdata ; read the select subset of L0 images (12)

IDL> sxt_prep, sindex, sdata, osindex, osdata, /register ; generate L1 data (scattered light, dark current, Yohkoh jitter) NOTE - this command will take 3 or 4 minutes ...

IDL> index2map, osindex, osdata, smap ; generate the SXT map objects

IDL> plot_map,smap(0),/rotate,/over, lcolor=120 ; overplot SXT contours on the TRACE/MDI image

See Mapping Package by Dominic Zarro for more details and options http://orpheus.nascom.nasa.gov/~zarro/idl/maps.html

freeland@bullet