#!/usr/local/bin/perl
#use lib '/home/aaossl/hmj/LIB/perl5';
#push @INC,"/local/www/hmj/perl5";
use lib '/local/www/hmj/perl5';
use CGI ':standard';

## Now the results: ta da!

require '6dfcalc.pl';

($SNR,$nobj,$nsky,$n_dn,$eff) =
signal_to_noise(
   param('ccd'),
   param('speed'),
   param('grating'),
   param('zd'),
   param('moon'),
   param('mag'),
   param('wavel'),
   param('exptime')
	       ) unless not defined param('ccd'); 



# Define all our queries
$ccd = "Detector: ".
  popup_menu(-name=>'ccd',
	     -values=>['EEV'],
	     -default=>'EEV');
$speed = "Readout speed: ".
  popup_menu(-name=>'speed',
	     -values=>['XTRASLOW','SLOW','NORMAL','FAST'],
	     -default=>'NORMAL');
$grating = "Grating: ".
  popup_menu(-name=>'grating',
	     -values=>['270R','316R','300B','600R','600V','600U','1200I','1200R','1200V','1200B'],
	     -default=>'300B');
$zd = "Zenith distance (degrees): ".
  textfield(-name=>'zd',
	    -default=>'30',
	    -size=>2,
	    -maxlength=>2);
$moon = "Phase of moon: ".
  popup_menu(-name=>'moon',
	     -values=>['Dark','Grey','Bright'],
	     -default=>'Dark');
$mag = "Magnitude: ".
  textfield(-name=>'mag',
	    -default=>'16',
	    -size=>4,
	    -maxlength=>4);
$wavel = "Wavelength (Å): ".
  popup_menu(-name=>'wavel',
	     -values=>['4000','4500','5000','5500','6000','6500','8000'],
	     -default=>'5000');
$exptime = "Exposure time (s): ".
  textfield(-name=>'exptime',
	    -default=>'3600',
	    -size=>6,
	    -maxlength=>6);
# Set up the tables
$specttable = table({-cellpadding=>2},
		    Tr({-align=>'left'},
		       [
			td({-align=>'right'},$ccd) . td($speed) . td($grating) 
		       ]
		      )
		   );
			 
$sitetable = table({-cellpadding=>2},
		   Tr({-align=>'left'},
		      [
		       td({-align=>'right'},$zd) . td($moon)
		      ]
		     )
		  );

$asttable = table({-cellpadding=>2},
		  Tr({-align=>'left'},
		     [
		      td({-align=>'right'},$mag) . td($wavel) . td($exptime)
		     ]
		    )
		 );

$input_table = table({-border=>undef,-cellpadding=>5,
		      -bgcolor=>'#CCCCFF'},
		     Tr(
			[
			 td($specttable),
			 td($sitetable),
			 td($asttable)
			]
		       ),
		    );

$submit_table = table({-border=>undef,-cellpadding=>5,
		       -valign=>'top'},
		       Tr(
			  td(strong(submit(-label=>'Calculate'))
			     .td(defaults('Reset form')))
			 )
		      );

$results_table = table({-border=>undef,-cellpadding=>5,
		      -bgcolor=>'#CCCCFF'},
		       Tr(
			  [
			   td(b(font({size=>"+1"},"SNR"))) 
			     . td(b(font({size=>"+1"},sprintf "%6.1f",$SNR))),
			   td(sprintf "Nobj") . td(sprintf "%6.1f",$nobj),
			   td(sprintf "Nsky") . td(sprintf "%6.1f",$nsky),
			   td(sprintf "Nrn")  . td(sprintf "%6.1f",$n_dn),
			   td(sprintf "Sys effy")  . td(sprintf "%6.2f",$eff)
			  ]
			 ),
		      );

if (not defined param('ccd'))
    {
      $output_table = table({-border=>undef,-cellpadding=>5,
			     -bgcolor=>'#CCCCFF'},
			    Tr({align=>"center"},
			       [
			       td($results_table),
  			       td($submit_table)
			       ]
			      ),
			   );
    }
    else
    {
      $output_table = table({-border=>undef,-cellpadding=>5,
			     -bgcolor=>'#CCCCFF'},
			    Tr({align=>"center"},
			       [
				td($results_table),
				td($submit_table)
			       ]
			      ),
			   )
      };

  # Now print the form
print header;
print start_html({-title=>' 6dF Spectrograph SNR Calculator',
		  -bgcolor=>'white'}),
    h1('6dF Signal-to-Noise Calculator'),
    em('IMPORTANT: Please read the notes below before using'),
    p;


print start_form;

print table({-cellpadding=>2},
	    Tr(
	       td($input_table) . td($output_table)
	      )
	   );

print "<p>\n <H3>Points to note:</H3>
<UL>
<LI> Sensitivities are not currently well-determined for wavelengths outside
the range adopted here. In any case, the actual signal-to-noise ratio will
be more heavily influenced by fibre absorption (below ~3800 &Aring),
and by airglow (above ~7000 &Aring).
<LI> The signal-to-noise ratios are calculated <EM>per pixel</EM>.
<LI> Single integrations in excess of 1800 seconds are not recommended,
due to the increasing covering factor of cosmic rays. When you break up
an integration of several thousand seconds into a number of shorter
exposures, the final signal-to-noise ratio will always be less than
for the equivalent single exposure, owing to the fixed readout noise
contribution from each exposure.
<LI> <tt>Magnitude</tt> is the magnitude of your source <B>at the wavelength of
observation</B>. For wavelengths of 4000 or 4500 &Aring;, use the <I>B</I>
magnitude; for wavelengths of 5000 or 5500 &Aring;, use the <I>V</B>
magnitude; and for wavelengths of 6000 or 6500 &Aring;, use the <I>R</I>
magnitude.
<LI> <tt>Nobj</tt> is the number of electrons <B>per pixel</B> from the object,
summed over all the exposures,
<LI> <tt>Nsky</tt> is the number of electrons per pixel from the sky (above
comments for <tt>Nobj</tt> apply also to <tt>Nsky</tt>).
<LI> <tt>Nrn</tt> is the detector noise in electrons.";

print "<p>\n<hr>\n <em>Maintained by Brian Boyle (<a href=mailto:bjb\@aaoepp.aao.gov.au>bjb\@aaoepp.aao.gov.au</a>). Adapted from the RGO SNR Calculator
written by Helen Johnston</em>.";

print "<br>\n <em>Last modified 22 August 2002</em>";

print end_form;