; TELE520.PRO
;
; DPS, 20 August 1992
;
wavelength=627.0 & filename=''
; read file of wavelengths, common to both zenith angles
OPENR,unit,'wl.520',/GET_LUN
READF,unit,nw
w=FLTARR(nw) 
FOR i=0,nw-1 DO BEGIN
    READF,unit,wavelength
    w(i)=wavelength
ENDFOR
CLOSE,unit & FREE_LUN,unit
; read file of image file names for 0 deg z.a. images
OPENR,unit,'lite0',/GET_LUN
READF,unit,n0
IF (n0 NE nw) THEN BEGIN
    PRINT,STRING(n0,nw, $
     FORMAT='(I2," images at 0 deg doesn''t match ",I2," wavelengths!")')
    STOP
ENDIF
za0f=STRARR(n0)
FOR i=0,n0-1 DO BEGIN
    READF,unit,filename
    za0f(i)=STRCOMPRESS(filename,/REM)
ENDFOR
CLOSE,unit & FREE_LUN,unit
; read file of image file names for 57 deg z.a. images
OPENR,unit,'lite57',/GET_LUN
READF,unit,n57
IF (n57 NE nw) THEN BEGIN
    PRINT,STRING(n57,nw, $
     FORMAT='(I2," images at 57 deg doesn''t match ",I2," wavelengths!")')
    STOP
ENDIF
za57f=STRARR(n57)
FOR i=0,n57-1 DO BEGIN
    READF,unit,filename
    za57f(i)=STRCOMPRESS(filename,/REM)
ENDFOR
CLOSE,unit & FREE_LUN,unit
; read file of image file names for 0 deg z.a. dark frames
OPENR,unit,'dark0',/GET_LUN
READF,unit,nd0
za0d=STRARR(nd0) 
FOR i=0,nd0-1 DO BEGIN
    READF,unit,filename
    za0d(i)=STRCOMPRESS(filename,/REM)
ENDFOR
CLOSE,unit & FREE_LUN,unit
; read file of image file names for 57 deg z.a. dark frames
OPENR,unit,'dark57',/GET_LUN
READF,unit,nd57
za57d=STRARR(nd57)
FOR i=0,nd57-1 DO BEGIN
    READF,unit,filename
    za57d(i)=STRCOMPRESS(filename,/REM)
ENDFOR
CLOSE,unit & FREE_LUN,unit
; read file of pixels showing illuminated screen at 0 deg z.a.
OPENR,1,'mask0.dat' & READF,1,nm0 & wm0=INTARR(nm0)
READF,1,wm0 & CLOSE,1
; read file of pixels showing illuminated screen at 57 deg z.a.
OPENR,1,'mask57.dat' & READF,1,nm57 & wm57=INTARR(nm57)
READF,1,wm57 & CLOSE,1
; define minimum (i.e., spikefree) dark frame for 0 deg z.a.
FOR i=0,nd0-1 DO BEGIN
    rdkimg,za0d(i),h,dkf
    IF (i EQ 0) THEN dk0=dkf $
    ELSE BEGIN
        wl=WHERE(dkf LT dk0)
        dk0(wl)=dkf(wl)
    ENDELSE
ENDFOR
; define minimum (i.e., spikefree) dark frame for 0 deg z.a.
FOR i=0,nd57-1 DO BEGIN
    rdkimg,za57d(i),h,dkf
    IF (i EQ 0) THEN dk57=dkf $
    ELSE BEGIN
        wl=WHERE(dkf LT dk57)
        dk57(wl)=dkf(wl)
    ENDELSE
ENDFOR
; calculate mean and standard deviation of screen brightnesses versus
; wavelength at 0 deg z.a.
m0=FLTARR(n0) & sd0=m0
FOR i=0,n0-1 DO BEGIN
    rdkimg,za0f(i),h,im0
    im0=im0-dk0
    m0(i)=TOTAL(im0(wm0))/N_ELEMENTS(wm0)
    sd0(i)=STDEV(im0(wm0))
ENDFOR
; calculate mean and standard deviation of screen brightnesses versus
; wavelength at 57 deg z.a.
m57=FLTARR(n57) & sd57=m57
FOR i=0,n57-1 DO BEGIN
    rdkimg,za57f(i),h,im57
    im57=im57-dk57
    m57(i)=TOTAL(im57(wm57))/N_ELEMENTS(wm57)
    sd57(i)=STDEV(im57(wm57))
ENDFOR
OPENW,7,'signal.za'
out=[TRANSPOSE(w),TRANSPOSE(m0),TRANSPOSE(sd0),TRANSPOSE(m57), $
     TRANSPOSE(sd57)]
PRINTF,7,5,nw
PRINTF,7,out
CLOSE,7
PRINT,'Enter the nominal center wavelength (nm) of the filter'
READ,ncw
PRINT,STRING(MIN(w,MAX=wmx),wmx, $
      FORMAT='("Data span wavelengths from ",F5.1," nm to ",F5.1," nm;")')
PRINT,'Enter limits for wavelength axis'
READ,wlo,whi
!p.title="Passband of 520 nm Filter in PoCa Optics Module"
!x.title="Wavelength ( nm )"
!y.title="Average Signal from Center of Illuminated Screen ( DN )"
PLOT,w,m0,XRANGE=[wlo,whi],YRANGE=[0,MAX([m0+sd0,m57+sd57])],XSTYLE=1
ERRPLOT,w,m0-sd0,m0+sd0
OPLOT,w,m57,line=2
ERRPLOT,w,m57-sd57,m57+sd57
top=!Y.CRANGE(1)
wrange=whi-wlo
PLOTS,[wlo+0.05*wrange,wlo+0.10*wrange],[0.95*top,0.95*top]
XYOUTS,wlo+0.12*wrange,0.95*top,'0 !9%!x zenith angle'
PLOTS,[wlo+0.05*wrange,wlo+0.1*wrange],[0.9*top,0.9*top],linestyle=2
XYOUTS,wlo+0.12*wrange,0.9*top,'57 !9%!x zenith angle'
;
pbold=FINDFILE('/wesson/user/steele/PAC/filter/calib/*/*.spl',COUNT=nold)
PRINT,'You can overplot one of the following old passband curves for comparison:'
FOR i=0,nold-1 DO PRINT,STRING(i,pbold(i),FORMAT='(I1,2X,A)')
rfilter,wold,sold
nsold=sold*(MAX(m0)/MAX(sold))
OPLOT,wold,nsold,PSYM=4
PLOTS,[wlo+0.05*wrange,wlo+0.10*wrange],[0.85*top,0.85*top],PSYM=4
XYOUTS,wlo+0.12*wrange,0.85*top,'0 !9%!x z. a. (old)'
END