clear all
close all
x1 = -30e3; % coordinates of ref station 1
y1 = 0;
x2 = 20e3; % coordinates of ref station 2
y2 = 0;
xu_true = 10e3; % true x coordinate of user
yu_true = 20e3; % true y coordinate of user [FOR CASE 2 THIS IS 5e3]
R1true = sqrt( (xu_true-x1)^2 + (yu_true-y1)^2);
R2true = sqrt( (xu_true-x2)^2 + (yu_true-y2)^2);
rng_std = 10; % standard deviation of the ranging measurement error
for i = 1:5000,
R1meas = R1true + rng_std*randn;
R2meas = R2true + rng_std*randn;
xu = 5e3; % initializing the initial guess of the user position
yu = 5e3;
delta_pos = [999999; 999999];
while norm(delta_pos) > 1e-3,
R1 = sqrt((xu-x1)^2+(xu-y1)^2) % top equation on slide 4 but use xu for x and yu for y;
% This is the computed distance from ref station 1 to the
% guessed user position
H(1,1) = (xu-x1)/R1 % (1,1) element of bottom right 2x2 matix on slide 4
H(1,2) = (yu-y1)/R1 % (1,2) element of bottom right 2x2 matix on slide 4
R2 = sqrt((xu-x2)^2+(yu-y2)^2) % similar as above
H(2,1) = (xu-x2)/R2
H(2,2) = (yu-y2)/R2
deltaR = [1600;100]; % this is a 2x1 vector consisting of the range
% measurements minus the ranges calculated from the
% ref stations to the guessed user position
delta_pos =[44.7;-22.5] % final equation on slide 4 (or use ordinary least
% squares; i.e., eqns 9 or 10 on page 2 of the
% Mod04 linearization handout)
xu = xu + delta_pos(1);
yu = yu + delta_pos(2);
end
xu_err(i) = xu - xu_true;
yu_err(i) = yu - yu_true;
horz_err(i) = sqrt(xu_err(i)^2 + yu_err(i)^2);
end
plot(xu_err,yu_err,'.')
ylabel('y error [m]')
xlabel('x error [m]')
axis equal
Htru(1,1) = (xu_true-x1)/R1true;
Htru(1,2) = (yu_true-y1)/R1true;
Htru(2,1) = (xu_true-x2)/R2true;
Htru(2,2) = (yu_true-y2)/R2true;
G = [1 0;1 0];
XDOP = 0.9
YDOP = 2.55
HDOP = 1.41
theoretical_x_err_std = 1414
sim_x_err_std = std(xu_err)
theoretical_y_err_std = 10;
sim_y_err_std = std(yu_err)
theoretical_h_err_std = 10^4;
sim_horz_err_std = sqrt( sim_x_err_std^2 + sim_y_err_std^2 );
Why i can not get my plot? When i run the program still running with out stop in the command windows, when i select pause stop and i have values in the workspace and in the command windows but the quit debugging show red(first time) im a new guys learning matlab but now im confuse. Any one can help me what is wrong with the program and guide me to the correct path?? thanks in advance.
