如圖所示，至少需要4顆衛星的資料，知道這4顆衛星離目標點的距離數值，然後receiver表示使用者手持GPS的位置；可得方程組：

以下是matlab程式碼解上述方程組：

clear all;

clc;

load "D:\Desktop\local_1\local_Mat\location.txt";

c = 3*10^8;

pointAt = [0;0;0;0];

for u=1:6

lenAt = 1:8;

for k = 1:8

lenAt(k) = sqrt((location(k,2)-pointAt(1))^2 + (location(k,3)-pointAt(2))^2 + (location(k,4)-pointAt(3))^2 ) + c*pointAt(4);

end

lenAt = lenAt";

detlen = location(:,1) - lenAt;

A = zeros(8,4);

for k=1:8

A(k,1) = -(location(k,2)-pointAt(1))/(location(k,1)-c*pointAt(4));

A(k,2) = -(location(k,3)-pointAt(2))/(location(k,1)-c*pointAt(4));

A(k,3) = -(location(k,4)-pointAt(3))/(location(k,1)-c*pointAt(4));

A(k,4) = c;

end

detpoint = (A"*A)\A"*detlen;

pointAt = detpoint + pointAt;

% disp(pointAt);

end

disp("the ans is:");

disp(pointAt);

透過這個方法可以計算不止4顆衛星的資料的GPS位置，多餘的幾個資料可以減小GPS的測量誤差。