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<H2><A NAME="SECTION003037000000000000000"> </A>
<A NAME="extract"> </A>
<BR>
Extracting the Spectrum
</H2>
<P>
The limits of the object are defined in the keyword
<!-- MATH: $\fbox{OBJECT}$ -->
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ALT="\fbox{OBJECT}">.
A simple
row average is performed by:
<BR> <BR>
Midas...> <TT>SET/LONG OBJECT=189,196</TT> <BR>
Midas...> <TT>EXTRACT/AVERAGE corr56 ext56</TT> <BR>
<BR>
which is equivalent to the general MIDAS command:
<BR> <BR>
Midas...> <TT>AVERAGE/ROW ex56 = corr56 @189,@196 </TT> <BR>
<BR>
An optimal extraction algorithm is also available, requiring
the knowledge of the CCD detector parameters, a preliminary
definition of the sky background, as well as the values of
a polynomial order
<!-- MATH: $\fbox{ORDER}$ -->
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and a number of iterations
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The command:
<BR> <BR>
Midas...> <TT>EXTRACT/LONG ccd0056 ext56 sky56</TT> <BR>
<BR>
applies the Horne's optimal extraction algorithm to the
image <B>ccd0056.bdf</B> and performs the sky subtraction to generate
the output image <B>ext56.bdf</B>.
<P>
<BR><HR>
<ADDRESS>
<I>Petra Nass</I>
<BR><I>1999-06-15</I>
</ADDRESS>
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