xgridw.m

GPS TOOLBOX包含以下内容： 1、GPS相关常量和转换因子； 2、角度变换； 3、坐标系转换： &#61656 点变换； &#61656 矩阵变换； &#61656 向量变换

%                                xgridw.m
%  Scope:  This MATLAB program generates and plots the longitude-latitude WAAS
%          grid as specified in [1].
%  Usage:  xgridw
%  Inputs:   - selection of option to save the generated data; the mat-file 
%              fgridw.mat is the output file 
%  Outputs:  - generated latitude-longitude WAAS grid data into the specified
%              mat-file (optional)
%            - graph of the latitude-longitude WAAS grid (2353 space 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
%  External Matlab macros used:  gridwaas     
%  Last update:  11/04/00
%  Copyright (C) 1998-00 by LL Consulting. All Rights Reserved.

clear
yes = 'y';
close all

%  Generate the WAAS grid data

[lat,lon] = gridwaas;

%  Save the WAAS grid data (optional)

disp('  ');
answer = input('Do you to save the generated grid data (y/n)[n]?  ','s');
if isempty(answer)
   answer = 'n';
end   
if (strcmp(answer,yes) == 1)
   disp('  ');
   disp('The Latitutde-Longitude WAAS grid is saved in file latlon.mat');
   save  fgridw lat lon
end

%  Execute the graph of the WAAS grid

figure(1)
plot(lon,lat,'*'), ...
title('WAAS Longitude-Latitude grid (2353 space points)'),...
xlabel('Longitude, in degrees'),...
ylabel('Latitude, in degrees'),...
axis([0 360 0 90]);

disp(' ');
disp('End of the program  XGRIDW ');
disp(' ');