plworldini.m

In the planning stage of a GNSS-measurement campaign it is useful to compute several design para-met

function plworldini (eph,tsat,xsat,ysat,zsat,satpos,colpos,coltrack);
%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
%    satpos - string with date and time for which to show the 
%             satellite positions as red points in the plot
% Optional input arguments:
%    colpos   - color string for satellite positions (default 'r')
%    coltrack - color string for satellite tracks (default 'b')

%
% Output arguments:
%    none

% ----------------------------------------------------------------------
% File.....  : plworldini.m
% Date.....  : 20-JUN-2001
% Version..  : 1.0
% Created by : Sandra Verhagen
% Based on   : plworld.m (in SKYLAB)
% Author...  : Peter Joosten
%              Mathematical Geodesy and Positioning
%              Delft University of Technology
% ----------------------------------------------------------------------

if nargin < 7
    colpos = 'r'; coltrack = 'b';
end

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


hold on;

% -----------------------------------------------------
% --- Coastlines, limits, grid, labels and such ... ---
% -----------------------------------------------------

set (gca,'Xlim',[-180 180]);
set (gca,'Ylim',[-90 90]);

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

% ------------------------------
% --- Plot satellites tracks ---
% ------------------------------
tnow = mktsat ( satpos, satpos, 300);
idx2 = find(abs(tsat-tnow)==min(abs(tsat-tnow)));

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))),coltrack);
    set (h,'LineWidth',0.5);
    hold on

  end;
    h = plot (rad2deg(plh(2,idx2)),rad2deg(plh(1,idx2)),colpos);
    set (h,'Marker','p','Markersize',7,'LineWidth',4);


    %  [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;