After having read the WBS data with YODAT, you can get a light curve of the
count rate of the ratio of HXS-PHi-j to HXS-PHk-l with UTPLOT.
IDL> hxsph1=mk_hxsph(index,data,xtime=xtime,channel=[i,j])
IDL> hxsph2=mk_hxsph(index,data,xtime=xtime,channel=[k,l])
MK_HXSPH is a function for making a float array of HXS-PH data.
Next you extract background data.
IDL> bgph=out_hxsph(index,data,/disp)
IDL> bgph=out_hxsph(index,data,stime=stime)
OUT_HXSPH is a function for output of HXS_PH data structure.
You subtract the background data and plot it.
IDL> subph1=hxsph1-total(bgph.signal(i:j))
IDL> subph2=hxsph2-total(bgph.signal(k:l))
IDL> utplot,xtime,subph2/subph1,index(0)
NOTE: You must be careful of the limitation due to dead time correction (see
DTCF_PH_HXS.PRO in the Reference Guide).