gpsmain.txt

An Example Simulation of Differential GPS

% GPSlog.m
% Author: Jim Connor ([e-mail])
% 03/05/2002
% Program reads a log file produced by the NovAtel RT20 
% receiver and imports data into the matlab workspace
% The program then graphs the scatter plot in NED coordinates
% and calculates the CEP. Also displays the  mean coordinates

R = input('What type of log file is it? 1=POSA   2=P20A   3=P20A and DOPA   ');

% Input dialog box to enter the GPS log file to open
% Format is filename.txt   Ex: GPSlog2.txt

file = INPUTDLG('Enter the File name','Enter GPS log file to open');
file=char(file);  % the file must be a character array to work
 
% Textread opens the file, pulls out information, and stores it in
% the four arrays. See 'help textread' for programming format

if R==1
    [time lat long height] = textread(file, ' %*s %*d %f %f %f %f %*[^\n]', 'delimiter',',');

elseif R==2
      [time sat lat long height rt20stat stat] = textread(file, ' %*s %*d %f %*f %d %f %f %f %*f %*f  %*f  %*f  %*f  %*f  %d %d %*[^\n]', 'delimiter',',');
      
else   GPSDOP;
end

GPSConvert      %Changes Longitude and Latitude coordinates to NED coordinates
GPSCEP          %Calls file that calculates the CEP
GPSPlot         %Plots the scatter plot
GPSCalculate    %Displays CEP and mean LAT, LONG and Height