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<H2><A NAME="SECTION003038000000000000000"> </A>
<A NAME="flux-cal"> </A>
<BR>
Flux Calibration
</H2>
<P>
Parameters for instrumental response estimation and flux
calibration are displayed by the command:
<BR> <BR>
Midas...> <TT>SHOW/LONG f</TT> <BR>
<BR>
The flux calibration consists of correcting for atmospheric extinction
using a table
<!-- MATH: $\fbox{EXTAB}$ -->
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and of comparing the one-dimensional
reduced spectrum of a standard star
<!-- MATH: $\fbox{STD}$ -->
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to a reference flux
table
<!-- MATH: $\fbox{FLUXTAB}$ -->
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ALT="\fbox{FLUXTAB}">.
The sequence:
<BR> <BR>
Midas...> <TT>SET/LONG FLUXTAB=fei110 EXTAB=atmoexan</TT> <BR>
Midas...> <TT>PLOT/FLUX</TT> <BR>
Midas...> <TT>EXTINCTION/LONG std23 ex23</TT> <BR>
<BR>
plots the flux table and corects the one-dimensional reduced
spectrum <B>std23</B> for the atmospheric extinction. The
instrumental response can be estimated by filtering with the
command:
<BR> <BR>
Midas...> <TT>RESPONSE/FILTER ex23</TT> <BR>
Midas...> <TT>PLOT/RESPONSE</TT> <BR>
<BR>
or by polynomial or spline interpolation using the sequence:
<BR> <BR>
Midas...> <TT>INTEGRATE/LONG ex23</TT> <BR>
Midas...> <TT>RESPONSE/LONG fit=SPLINE</TT> <BR>
Midas...> <TT>PLOT/RESPONSE</TT> <BR>
<BR>
The obtained response is stored in the image <B>response.bdf</B>
and can be applied to any reduced, extinction corrected spectrum using the
command:
<BR> <BR>
Midas...> <TT>CALIBRATE/FLUX exspec spectrum</TT> <BR>
<P>
<BR><HR>
<ADDRESS>
<I>Petra Nass</I>
<BR><I>1999-06-15</I>
</ADDRESS>
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