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OK
OKECAL
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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.
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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
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