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For the storage of control parameters and results, the context LONG uses a number of special keywords. They are intialised by the command SET/CONTEXT LONG, their values can at any time be listed by typing SHOW/LONG. The following table provides a brief description of the purpose of the LONG keywords:

Table 6.7: Keywords Used in Context LONG
Parameter Description
ALPHA Rejection parameter for lines matching [0,0.5]
AVDISP Average dispersion per pixel
BETA Non-linearity in mode LINEAR
BIAS Bias image or constant
BIASOPT Bias Correction (YES/NO)
COERBR Table of coefficients for RBR
COMET Combination method (AVERAGE/MEDIAN)
COORFIL Name of coords table of GCOORD/LONG
COROPT Computes correlation
CORVISU Plots correlation peak
DARK Dark image or constant
DARKOPT Dark Correction (YES/NO)
DCX fit degree of the dispersion coeff.
DISPCOE Dispersion coefficients
EXTAB Extinction Table
EXTMTD Extraction method (AVERAGE, LINEAR)
EXTOPT Extinction Correction Option (YES/NO)
FDEG Flat fitting degree
FFIT Flat fitted function
FILTMED Radius of median filter
FILTSMO Radius of smoothing filter
FITD Degree of fit
FITD fit degree of the dispersion coeff.
FITYP Type of fit (POLY, SPLINE)
FLAT Flat-Field Image
FLATOPT Flat Correction (YES/NO)
FLUXTAB Flux Table of the standard star
FVISU Visualisation flag (YES/NO)
GAIN Gain (e-/ADU)
GUESS Guess session name
IMIN lower limit from LINCAT
INPNUMB Input generic name
INPUTF Input generic name
INSTRUME instrument
LINCAT line catalogue
LINTAB Table of line identifications
LOWSKY Lower, upper row number of lower sky
MAXDEV Maximum deviation (pixels)
NITER Number of iterations
NPIX size of the raw images in pixels
OBJECT Lower, upper row number of object spectrum
ORDER Order for optimal extraction

Table 6.8: Keywords Used in Context LONG (continued)
Parameter Description
OUTNUMB Output starting number
OUTPUTF Output generic name
RADIUS Radius for cosmics rejection
REBEND Final wavelength for rebinning
REBOPT Rebin Option (YES/NO)
REBSTP Wavelength step for rebinning
REBSTRT Starting wavelength for rebinning
RESPLOT Plot flag for response computation
RESPONSE Response Image
RESPOPT Response Correction Option (YES/NO)
RESPTAB Intermediate Response Table
RON Read-Out-Noise (ADU)
ROTOPT Rotation Option (YES/NO)
ROTSTART Y-start after rotation
ROTSTEP Y-step after rotation
SEAMTD Search centering method (GAUSS, GRAV, MAXI)
SESSION Session name
SHIFT Shift in pixels
SIGMA Threshold for rejection of cosmics (std dev.)
SKYMOD Mode of fitting
SKYORD Orderfor sky fit
SMOOTH Smoothing factor for spline fitting
START start points of the raw image.
STD Standard Star Spectrum
STEP start points of the raw image.
THRES Threshold for line detection (above local median)
TOL tolerance in Angstroms for wavelength ident.
TRIM Trim window (x1,y1,x2,y2) in pixels
TRIMOPT Trim Option (YES/NO)
TWODOPT Computes bivariate polynomial option.
UPPSKY Lower, upper row number of upper sky
WCENTER Central wavelength
WIDTH Window size in X for line detection (pixels)
WLC wavelength calibration image
WLCMTD Wavelength calibration method (IDENT,GUESS)
WLCNITER Minimum, Maximum number of iterations
WRANG wavelength range to take from LINCAT
YSTART Starting row for the calibration (pixel value)
YSTEP Step in Y for line searching (pixels)
YWIDTH Window size in Y for line detection (pixels)

next up previous contents
Next: Example Up: Long-Slit and 1D Spectra Previous: Command Summary
Petra Nass