pldopworld.m

Sky lab calculate position of satellite in GNSS systems and calculate elevation and azimuth them and

function pldopworld (eph,tsat,xsat,ysat,zsat,PDOP);
%PLWORLD: Plot satellite tracks over the world
%
% The function create a plot showing the tracks of satellites over
% the world.
%
% Syntax:
%    plworld (eph,tsat,xsat,ysat,zsat);
%
% Input arguments:
%    eph    - Ephemerides
%    tsat   - Times on which positions are computed
%    xsat   - X-coordinates in earth-fixed WGS'84 coordinates
%    ysat   - Y-coordinates in earth-fixed WGS'84 coordinates
%    zsat   - Z-coordinates in earth-fixed WGS'84 coordinates
%
% Output arguments:
%    none

% ----------------------------------------------------------------------
% File.....: plworld.m
% Date.....: 11-JUN-1999
% Version..: 1.0
% Author...: Peter Joosten
%            Mathematical Geodesy and Positioning
%            Delft University of Technology
% ----------------------------------------------------------------------

% --------------------------------------
% --- Create the figure, set options ---
% --------------------------------------

h = figure('Units','normalized', ...
	   'Position',[0.2 0.2 0.6 0.4], ...
	   'Color',[0 0 0], ...
	   'Name','Satellite tracks', ...
	   'NumberTitle','off');

h = axes ('Units','normalized', ...
	  'Position',[0.05 0.05 0.90 0.90], ...
	  'Color',[0 0 0], ...
	  'XColor',[1 1 1], ...
	  'YColor',[1 1 1], ...
	  'Xgrid','on', ...
	  'Ygrid','on', ...
          'Xtick',[-180:30:180], ...
	  'Ytick',[-90:30:90], ...
	  'Box','on');

hold on;

imagesc([-180 180],[90 -90],PDOP);
h1=colorbar
set(h1,'XColor',[1 1 1], 'YColor',[1 1 1]);
% -----------------------------------------------------
% --- Coastlines, limits, grid, labels and such ... ---
% -----------------------------------------------------
axes(h);
set(h,'box','on')
set (gca,'Xlim',[-180 180]);
set (gca,'Ylim',[-90 90]);

load coast;
h = plot (long,lat,'w-');

% ------------------------------
% --- Plot satellites tracks ---
% ------------------------------

lcol = get(gca,'ColorOrder');

for i = 1:size(eph,1);
  
  plh = xyz2plh ([xsat(i,:); ysat(i,:); zsat(i,:)]);
  idx = [0 find(abs(plh(2,1:size(plh,2)-1)-plh(2,2:size(plh,2)))>deg2rad(180)) size(plh,2)];

  for j = 1:length(idx)-1;

    h = plot (rad2deg(plh(2,idx(j)+1:idx(j+1))),rad2deg(plh(1,idx(j)+1:idx(j+1))));
    set (h,'Marker','+');
    set (h,'LineWidth',2);
    set (h,'Color',lcol(mod(i,size(lcol,1))+1,:));

  end;
  
%  [tx,ty] = pol2cart (deg2rad(-azim(i,idx1(idx2(j)+1))+90),90-elev(i,idx1(idx2(j)+1)));
%  tx = tx - 2; ty = ty + 2;
%  h  = text(tx,ty,num2str(eph(i,1)));
%  set (h,'Color',lcol(mod(i,size(lcol,1))+1,:));
      
end;