<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 98.1p1 release (March 2nd, 1998) originally by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>Data Format</TITLE> <META NAME="description" CONTENT="Data Format"> <META NAME="keywords" CONTENT="vol2"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <LINK REL="STYLESHEET" HREF="vol2.css"> <LINK REL="next" HREF="node492.html"> <LINK REL="previous" HREF="node490.html"> <LINK REL="up" HREF="node489.html"> <LINK REL="next" HREF="node492.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html7560" HREF="node492.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html7557" HREF="node489.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html7551" HREF="node490.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html7559" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="icons.gif/contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html7561" HREF="node492.html">Data Reduction</A> <B> Up:</B> <A NAME="tex2html7558" HREF="node489.html">PISCO</A> <B> Previous:</B> <A NAME="tex2html7552" HREF="node490.html">Introduction</A> <BR> <BR> <!--End of Navigation Panel--> <H1><A NAME="SECTION002820000000000000000"> Data Format</A> </H1> Formally, the raw data files produced by the PISCO data acquisition programme conform to the standards of FITS images or MIDAS bulk data frames and can, therefore, be treated with all MIDAS commands pertaining to images. By contrast, the content of these data files is very highly non-standard and is a mixture of spectrum-like images and tables (does not apply to calibration frames, cf. below). <P> As described in the PISCO Operating Manual, there are two types of data files: <DL> <DT><STRONG>Calibration frames</STRONG> <DD>contain 8 lines with 32 data points each which correspond to the 32 positions of the half-wave plate. In the first seven lines, seven measurements are stored; the eigth line holds their normalised mean. <DT><STRONG>Normal data frames</STRONG> <DD>also consist of 8 lines with 32 data points each. However, their contents is as follows: <DL COMPACT> <DT>Line 1: <DD>raw data of channel X in the direct mode of the compensating phase plate. <DT>Line 2: <DD>raw data of channel Y in the direct mode of the compensating phase plate. <DT>Line 3: <DD>raw data of channel X in the rotated mode of the compensating phase plate. <DT>Line 4: <DD>raw data of channel Y in the rotated mode of the compensating phase plate. <DT>Lines 5-7: <DD>results of on-line reduction as described in the Operating Manual. They are not used by MIDAS. <DT>Line 8: <DD>not used at present. </DL></DL> <P> <HR> <!--Navigation Panel--> <A NAME="tex2html7560" HREF="node492.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html7557" HREF="node489.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html7551" HREF="node490.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html7559" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="icons.gif/contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html7561" HREF="node492.html">Data Reduction</A> <B> Up:</B> <A NAME="tex2html7558" HREF="node489.html">PISCO</A> <B> Previous:</B> <A NAME="tex2html7552" HREF="node490.html">Introduction</A> <!--End of Navigation Panel--> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>
