gridwaas.m

GPS software toolbox for GPS receiver development

%                             gridwaas.m
%  Scope:   This MATLAB macro generates latitude-longitude WAAS grid specified
%           in [1].
%  Usage:   [lat,lon] = gridwaas
%  Description of parameters:
%           lat    - output, latitude in degrees (for 2353 points)
%           lon    - output, longitude in degrees (for 2353 points)
%  Reference: 
%           [1] Anonym., Minimum operational performance standards for Global 
%               Positioning System/Wide Area Augmentation System airborne 
%               equipment. RTCA / DO-229, January 16, 1996, prepared by SC-159
%  Last update:  04/23/00
%  Copyright (C) 1998-00 by LL Consulting. All Rights Reserved.

function  [lat,lon] = gridwaas

lat = zeros(2353,1);
lon = zeros(2353,1);
point = 0;
for lattemp = 0:3:90
   denom = cos(lattemp*pi/180.);
   if (denom < 0.0083333)
       denom = 360.;
   else
      denom = 3./denom;
   end     
   lonstep = floor(0.5 + (360./denom));
   for loncnt = 0:(lonstep-1)
      point = point + 1;   
      lat(point) = lattemp;
      lon(point) = loncnt*360./lonstep;
   end
end