______________________________________________________________________________ OK OKECAL ______________________________________________________________________________ Creates a calibration array to convert observed (SCRUNCHED) spectra (in wavelength) to absolute flux F(lambda) vs lambda. For each LAMBDA interval common to the observed standard spectrum and the flux library, OKECAL reads ABv = -2.5*LOG10(FNU) - 48.60 and computes : OKEMAGx = ABv + 48.60 - 2.5*LOG10(C/x*x) x = lambda v = frequency __ \ where RATE = /_ COUNTS/(DWELL*LAMBDA RANGE) = -2.5*LOG10(Fx) OBSMAGx = -2.5*LOG10(RATE) : RATE = obs counts/sec/A CALMAGx = OBSMAGx - EXTCO*AIRMAS - OKEMAGx = -2.5*LOG10(obs rate above atmos/Fx) This is fitted (spline or poly) to a continuous curve K(I) for each pixel where : K(I) = -2.5*LOG10(obs rate above atmos/Fx) and LAMBDA = XST + (I-1)*XINC This curve is stored in the CAL array. ______________________________________________________________________________ EXAMPLE OPTION .OK OPEN FILE WITH OBSERVED STD TO BE CALIBRATED FILI=SLINE There are 4 maps in the file Reading from the file 1 rows of 2040 pixels in R4 format MAPI=3 Start value increased by 1/2 channel in BINVAL ROWI=1 TYPE VALUE FOR DWELL DWELL= 490.000 PLOT=N OKESTD=L930 L930-80 DB OKE Ap.j.suppl.27 LOOK=Y START END MAG(lambda) 3360.0 3440.0 34.54 ____________ List abreviated for this example 5600.0 5680.0 36.05 SPECIFY 3 COEFS FOR EXTINC = A/X**4 + B/X**1.3 + C where X = LAM/10000 DEFAULTS ARE : RAYLEIGH A = 0.0092 DUST B = 0.0 CONSTANT C = 0.06 EXTCO= 0.920000E-02 0.000000E+00 0.600000E-01 AIRMAS = 1.1505 LAMBDA OBSMAG OKEMAG CALMAG EXTINC 1 3400.0 0.000 34.535 -35.396 0.861 2 3480.0 1.203 34.606 -34.194 0.791 _____________ Abreviated 29 5640.0 0.615 36.054 -35.613 0.174 NDEV=3 SELECT OPTION D delete points F fit curve P plot the calibration S save the calibration curve OPT=D DEL=1,2 SELECT OPTION D delete points F fit curve P plot the calibration S save the calibration curve OPT=F SELECT TYPE OF FIT 0 spline n nth order poynomial FIT=5 COEFFS 97.173940 -0.11641583 3.89959047E-05 -6.10004768E-09 4.28635702E-13 -9.77659330E-18 SIGMA 2.34563E-02 POINT X VAL Y VAL CAL VAL DIF 1 3560.000 -34.994 -35.013 -0.019 2 3640.000 -35.109 -35.095 0.013 _________________ Abreviated 24 5480.000 -35.337 -35.348 -0.011 IS FIT OK ? OK=Y SAVE THE CALIBRATION CURVE ? SAVE=Y CREATE THE CALIBRATION FILE NMAPS= 1 NPLNS= 1 NROWS= 1 NELS= 2040 TYPE FILENAME (<CR> FOR DEFAULT) FILC=SCALIB Creating new file TYPE MAPNUMBER FOR CALIBRATION ARRAY MAPC=1 DO YOU WANT A HARD COPY PLOT ? HARD=Y ______________________________________________________________________________