; file: GLLUVS2:[MARINER9.PDS_ARCHIVE.CALIBRATION]HOW_TO_CALIB.DOC
;		May 15, 2002 - kes
; The following file was created on ANSA to replicate the calibration
; procedure used by Barth and Hendrix to calculate Reflectance

; To calculate Reflectance, use:
;  relectance=(data-bkground)*(gainstate corr)*(1.52^2)/(calib*solarf*4*100)
;
; notes: gainstate correction is determined with the MMRD.PRO software
; sample_number is the position in the IDL array, ie wavelength

; F_WAVE units are Angstoms, with 15 Angstom resolution, and is from 
;        laboratory calibration

; CALIB units are (Data_Number * sample_number)/kR and is from lab calibration
; Data_Number is raw counts (=instrument output)

; SOLARF (pi*F) units are kR/(4*100*sample_number)  at F-channel
;        15 Angstrom resolution. It is from JPL Technical Report
;        No. 32-951, A Digitized Solar Ultraviolet Spectrum, by
;        R.T. Brinkman, A.E.S. Green, and C.A. Barth

; OZONE units are cm-1. It's source is JPL Publication 94-26, Chemical
;        Kinetics and Photochemical Data for Use in Stratospheric Modeling,
;        Evaluation Number 11, by W.B. Demore, et al.

IDL> openr,1,'mr10.udat'		; one of Barth's original
IDL> a=assoc(1,intarr(1265))		; EDR data extraction/analysis tapes
IDL> ozone=a(732:1259,3927)		; F-channel area (528 values)
IDL> f_wave=a(732:1259,3929)
IDL> plot,f_wave+868			; original offset for PDP byte scale
IDL> calib=a(732:1259,3926)		
IDL> plot,calib
IDL> solarf=a(732:1259,3925)
IDL> plot,solarf
IDL> f_wave=f_wave+868
IDL> plot,f_wave,solarf
IDL> plot,f_wave,calib 
IDL> 
IDL> 
IDL> close,12
IDL> openw,12,'mm71_fcal_solar.dat'
IDL> help,ww
WW              FLOAT     = File<mm71_fcal_solar.dat> Array[528]
IDL> ww(0)=float(f_wave)
IDL> ww(1)=float(calib)
IDL> ww(2)=float(solarf)
IDL> ww(3)=float(ozone)
IDL> close,12,11
IDL> openr,11,'mm71_fcal_solar.dat'
IDL> aa=assoc(11,fltarr(528))
IDL> plot,aa(0)
IDL> plot,aa(1)
IDL> plot,aa(2)
IDL> plot,aa(3)
IDL> plot,aa(0),aa(2)
IDL> close,11

; mm71_fcal_solar.dat is the file available on the web site