skydip_investigation

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

  function skydip_investigation(d)

  analyzes sky_dip_investiagation.sch, where we do sky dips at different
  azimuth values.

  sjcm

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

0001 function skydip_investigation(d)
0002 
0003 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0004 %
0005 %  function skydip_investigation(d)
0006 %
0007 %  analyzes sky_dip_investiagation.sch, where we do sky dips at different
0008 %  azimuth values.
0009 %
0010 %  sjcm
0011 %
0012 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0013 
0014 % first we cut unwanted data.
0015 % f5 is a sky dip, f10 is the noise diode
0016 d_dip = framecut(d, bitsearch(d.array.frame.features, 5, 'any'));
0017 d_noise = framecut(d, bitsearch(d.array.frame.features, 10, 'any'));
0018 
0019 
0020 azvals = unique(floor(d_dip.antenna0.servo.az*10))/10;
0021 for m=1:length(azvals)
0022   ind = d_dip.antenna0.servo.az>azvals(m)-0.5 & ...
0023       d_dip.antenna0.servo.az<azvals(m)+0.5;
0024   dc  = framecut(d_dip, ind);
0025 
0026   % so the first thing we want to do is normalize for the power when the
0027   % antenna is pointed straight up.
0028   thisY = dc.antenna0.receiver.data(:,[1 6]);
0029   f = find(dc.antenna0.servo.el==max(dc.antenna0.servo.el),1);
0030   y(:,1) = thisY(:,1)./thisY(f,1);
0031   y(:,2) = thisY(:,2)./thisY(f,2);
0032 
0033   % check for rfi/sun
0034   if(mean(var(y))>1)
0035     display('sun/source present in dip');
0036     noGood = 1;
0037   else
0038     noGood = 0;
0039   end
0040   
0041   % next we want to plot this normalized value against 1/sin(el)
0042   x = 1./(sind(dc.antenna0.servo.el));
0043 
0044   % now we fit a line to this, the value at the intercept, in these units,
0045   % is Tground/Tambient, the slope is tau
0046 
0047   plot(x,y);
0048   xlabel('csc(el)');
0049   ylabel('Normalized Channel');
0050   txt = sprintf('title(''az: %3.1f degrees'');', azvals(m));
0051   eval(txt);
0052   r = input('Keep this Point? [Y/N]:', 's');
0053   if(strcmp(r, 'y') || strcmp(r, 'Y'))
0054     noGood = 0;
0055   elseif(strcmp(r, 'n') ||  strcmp(r, 'N'))
0056     noGood = 1;
0057   elseif(strcmp(r, 'k'))
0058     keyboard;
0059   else
0060     noGood = 1;
0061   end
0062   
0063   if(~noGood)
0064     [tau(m,:) Tground(m,:)] = linfit(x,y);
0065     finY{m} = y;
0066     finX{m} = x;
0067   else
0068     display('Disregarding dip');
0069     tau(m,:) = nan;
0070     Tground(m,:) = nan;
0071     finY{m} = nan(size(y));
0072     finX{m} = nan(size(x));      
0073   end
0074   Tamb(m) = mean(dc.array.weather.airTemperature);
0075 
0076   
0077   
0078   
0079   clear y;
0080   clear x;
0081   
0082 end
0083 display('Done displaying plots');
0084 
0085 
0086 Tg = Tground.*repmat(Tamb', [1 2]);
0087 
0088 
0089 % now for plotting.
0090 figure(1)
0091 setwinsize(gcf, 800, 700);
0092 subplot(2,1,1)
0093 plot(azvals, tau);
0094 xlabel('Azimuth (degrees)');
0095 ylabel('Tau');
0096 legend('Channel 1', 'Channel 2');
0097 
0098 subplot(2,1,2);
0099 plot(azvals, Tg);
0100 xlabel('Azimuth (degrees)');
0101 ylabel('T Ground [K]');
0102 legend('Channel 1', 'Channel 2');
0103 
0104 gtitle('Sky Dip Investigation');
0105 
0106 figure(2)
0107 setwinsize(gcf, 800, 700);
0108 subplot(2,1,1);
0109 for m=1:length(finX)
0110   plot(finX{m}, finY{m}(:,1));
0111   hold on
0112 end
0113 xlabel('csc(elevation)');
0114 ylabel('Normalized data');
0115 title('Channel 1');
0116 hold off
0117 
0118 subplot(2,1,2);
0119 for m=1:length(finX)
0120   plot(finX{m}, finY{m}(:,2));
0121   hold on
0122 end
0123 xlabel('csc(elevation)');
0124 ylabel('Normalized data');
0125 title('Channel 2');
0126 gtitle('Sky dips at different Azimuths');
0127 hold off
0128 
0129 return;
0130 
0131 
0132