Home > pointing > star_set.m

star_set

PURPOSE ^

star_set(lst)

SYNOPSIS ^

function star_set(lst,ellim,maglim,lat, minuteDiff)

DESCRIPTION ^

 star_set(lst)

 Find the set of stars which are bright and available for pointing
 at a given LST

 To get the lst type "print $time(lst)" in szaViewer

 e.g.: star_set(19.1)

 Take the resulting list of numbers and paste it into
 /home/szadaq/carma/sza/array/sch/point_manual.sch

 Then run using:
 schedule /home/szadaq/carma/sza/array/sch/point_manual.sch

 Then center up each star using widget and hit the button
 Be sure to keep a note of which data file in
 /home/szadaq/arc contains the data from the star pointing run

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function star_set(lst,ellim,maglim,lat, minuteDiff)
0002 % star_set(lst)
0003 %
0004 % Find the set of stars which are bright and available for pointing
0005 % at a given LST
0006 %
0007 % To get the lst type "print $time(lst)" in szaViewer
0008 %
0009 % e.g.: star_set(19.1)
0010 %
0011 % Take the resulting list of numbers and paste it into
0012 % /home/szadaq/carma/sza/array/sch/point_manual.sch
0013 %
0014 % Then run using:
0015 % schedule /home/szadaq/carma/sza/array/sch/point_manual.sch
0016 %
0017 % Then center up each star using widget and hit the button
0018 % Be sure to keep a note of which data file in
0019 % /home/szadaq/arc contains the data from the star pointing run
0020 
0021 if(~exist('ellim'))
0022   ellim=[];
0023 end
0024 if(~exist('maglim'))
0025   maglim=[];
0026 end
0027 if(~exist('lat'))
0028   lat=[];
0029 end
0030 
0031 if(isempty(ellim))
0032   ellim=30;
0033 end
0034 if(isempty(maglim))
0035   maglim=4.0;
0036 end
0037 if(isempty(lat))
0038   lat=37; % OVRO
0039 end
0040 
0041 
0042 % Read in star catalog data
0043 [cat.name,ra,dec,cat.mag] = ...
0044   textread('stars.cat','J2000 %s %s %s %*s %*s # %f','commentstyle','matlab');
0045 
0046 % Convert ra,dec to fractional degrees
0047 [cat.ra,cat.dec]=ast2fracdeg(ra,dec);
0048 
0049 % Calc hour angle for given lst
0050 cat.ha=lst*15-cat.ra;
0051 
0052 % Calc az,el for site at given latitude
0053 d2r=pi/180; r2d=180/pi;
0054 [cat.az,cat.el]=hdl2ae(cat.ha*d2r,cat.dec*d2r,lat*d2r);
0055 cat.az=cat.az*r2d; cat.el=cat.el*r2d;
0056 
0057 % Cut down to stars above elevation and magnitude limits
0058 ind=cat.el>ellim&cat.mag<maglim;
0059 cat=structcut(cat,ind);
0060 
0061 % Cut out stars close to zenith as causes hangup
0062 ind=cat.el<83;
0063 cat=structcut(cat,ind);
0064 
0065 % Move az<-90 sources to +ve
0066 ind=cat.az<-90;
0067 cat.az(ind)=cat.az(ind)+360;
0068 
0069 % Sort to decreasing azimuth order to make for an efficent
0070 % star pointing run
0071 [x,ind]=sort(cat.az);
0072 cat=structcut(cat,flipud(ind));
0073 
0074 % Print list for inclusion into pointing script
0075 junk = lst:minuteDiff/60:(lst + minuteDiff/60*length(cat.az));
0076 for i=1:length(cat.az)
0077   disp(sprintf('{%8s, %3.2f}, # %7.2f %6.2f %5.2f',...
0078            cat.name{i},junk(i),cat.az(i),cat.el(i),cat.mag(i)));
0079 end
0080

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