Program: LRSCAL Purpose: Generate a calibrated LRS spectrum from data in an IRDS Category: IRAS File: lrscal.c Author: P.R. Roelfsema Keywords: IRSET= Name of input IR data set [quit] IRSETOUT= Name of output IR data set [no output] POS= Position at which spectrum is to be generated [ same as before ] Giving Q(UIT) at this keyword will stop the program. SNIP= Give snip number of spectrum to process [ all remaining spectra ] Possible answers are : Q(UIT) - loop the program back to the POS= keyword. A(LL) - (re)process all spectra in the data set. n - process snip number n. If all spectra have been calibrated has the same effect as typing Q(UIT). *** ISLIM= In-Scan offset where spectrum extraction starts in arcsec [ 2000 ] *** SINGLE= Use single baseline component ? [ N ] The baseline subtraction for LRS is best done using two separate baselines; one for those data from before the source crossed the aperture and one derived from the data after the aperture crossing. This is the standard mode (SINGLE=N). In low signal to noise conditions this approach gives rise to wildly varying baslines, and thus in that case it is better to determine one global baseline level, this can be forced by specifying SINGLE=Y. *** BWIN= Set default window for ALL snips [ -1000 -250 250 1000 ] *** BWINn= Windows (inscan) for baseline of snip n [ BWIN= value] This keyword can be used to specify up to two windows in the in-scan direction. Through the data within these windows a straight line is fitted which is subsequently subtracted from the data. e.g. BWIN3=-300 -200 200 300 (in arcsec). UNITS= Give units of data after calibration [LFL] Options are: Jy - F(lambda) in Jy Wm - F(lambda) in Wm^-2mu^-1 LFL - lambda*F(lambda) in Wm^-2 L4FL - lambda^4*F(lamba) in Wm^-2mu^3 GRDEVICE= Give graphics device for display [ list available devices ] ***COHEN= Apply Cohen correction factors? [ Yes ] ***MXGAIN= Specify maximum cross-scan gain to be applied [ 2 ] This keyword allows the user to discard data taken with the source of interest very close to the edge of a detector. This is done by setting a limit on the maximum correction for the cross-scan gain variations. The cross-scan gain corrections vary from 1.0 at the centre of the detectors upto 5-6 near the edges. ***ALIGN= Align spectral halves? [ Yes ] If no is specified the short wave and long wave spectral halves are not aligned. ***MINMAX= Min and max levels to be plotted [ min and max of data ]. ***PSC= Point source catalogue fluxes (Jy) at 12 and 25 mu [ none ]. ***THICK= Do you want thick lies in plot? [ Yes ]. Updates: May 10, 1990: PRR, Document created. Dec 17, 1990: PRR, Version 1.0. Feb 11, 1991: PRR, Upgrade for PGPLOT. Feb 13, 1991: PRR, Major rewrite. Jun 12, 1991: PRR, new flux-calibration. Aug 9, 1991: PRR, min nr. of ticks implemented rms noise calculation. Oct 10, 1991: WZ, PGPLOT standard names implemented Mar 19, 1992: HB, New interface to irds_enquire_snip Sep 23, 1992: PRR, Changed BWIN default, baseline subtraction, more UNITS. Mar 23, 1993: PRR, GRDEVICE not cancelled anymore Jul 20, 1993: PRR, added Cohen correction factors Jul 22, 1993: PRR, added MXGAIN and ALIGN options Aug 9, 1993: PRR, solved (?) crashes on HP Aug 11, 1993: PRR, changed BWIN= to BWINn= Aug 13, 1993: PRR, added BWIN= to BWINn=