%%%%%?gps?constellation?emluator?%%%%%%
clear
%?constant?defination%?????????????????
pi=3.1415926;
a=26609e3;????????????%軌道長半軸長，單位已經換算為?m
e=0.006;??????????????%軌道的偏心率
i_0=55*pi/180;??????????%基準時間t_0的軌道傾角
%?gpa?采用的橢球參數?%
a_e=6378137;??????????%地球橢球的長半徑
f_e=1/298.257223563;??%地球橢球體扁率
e_2=2*f_e-f_e^2;??????%GPS參考橢球第一偏心率的平方

%測站在大地坐標系中的經緯度數據經度L緯度B高度H?%
station=[118;32;300];
station（11）=station（11）*pi/180;%完成弧度轉換
station（21）=station（21）*pi/180;

L=station（11）;
B=station（21）;
H=station（31）;
%計算橢球的卯酉圈曲率半徑N
W=sqrt（1-e_2*sin（B）^2）;
N=a_e/W;
%將測站在大地坐標系下的坐標轉換為地球坐標系的空間直角坐標[xpypzp]
xp=（N+H）*cos（B）*cos（L）;
yp=（N+H）*cos（B）*sin（L）;
zp=（N*（1-e_2）+H）*sin（B）;
%求系數陣h
h（11）=-sin（B）*cos（L）;
h（12）=-sin（B）*sin（L）;
h（13）=cos（B）;

h（21）=-sin（L）;
h（22）=cos（L）;
h（23）=0;

h（31）=cos（B）*cos（L）;
h（32）=cos（B）*sin（L）;
h（33）=sin（B）;

E0=15;
mu=3.986008e14;???????%開普勒常數，單位為m3/s2
w_ie=7.292115147e-5;??%地球自轉平均角速率，單位rad/s
%?衛星軌道參數矩陣epoch:2007-04-01?14:21:46，第一列衛星標號1~30，第二列升交點赤經W_0，第三列平近點角距M_0?%
sate=[1?12.4664?313.6181;2?13.2561?99.1277;3?10.4480?41.9519;4?12.4727?289.5653;5?11.6077?116.5486;6?10.5432?209.4507;
??????7?65.1275?73.1881;8?66.9823?101.9770;9?68.3454?286.8979;10?73.1479?200.4810;11?70.2154?77.1527;
??????12?125.5712?295.1060;13?128.3618?285.5386;14?131.8240?123.7737;15?131.3074?44.5724;16?130.3997?73.6977;
??????17?186.9655?97.3078;18?188.4401?98.7626;19?184.9619?319.1793;20?194.1995?55.7345;21?190.8460?172.0155;
??????22?253.5063?46.1491;23?251.3094?346.3001;24?241.0610?333.6671;25?252.3879?163.3319;26?250.2394?231.0366;
??????27?311.8862?334.8484;28?309.8682?287.5291;29?312.8828?146.8152;30?313.3067?94.0084];
%w=;????????????????????%近地點角
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
t_0=0;????????????????%星歷的參考歷元
t_k=0;????????????????%仿真時間單位s
a3=a^3;
n=sqrt（mu/a3）;???????%?n=（2*pi）/T=sqrt（mu/a3）應用了開普勒第三定律
i=1;
r=1;
for?j=1:30
?????sate（j3）=sate（j3）*pi/180;%平近點角
?????sate（j2）=sate（j2）*pi/180;%升交點赤經
end
s=43201;
dot_step=300;
q=0;
while?t_k????q=q+1;????????%各個矩陣的行數表示量
????t_k
????t（q1）=t_k;
????j=1;????????????%?衛星標號
????while?j<=30?????%各個矩陣的列數表示量
??????????M_k（qj）=sate（j3）+n*（t_k-t_0）;????
???????%%%%%%%%%%%%%?求偏近點角?E_k?%%%%%%%%%%%%%?
??????????Et_1（qj）=M_k（qj）;
??????????t_end=1;??
??????????while（t_end）
??????????????Et（qj）=M_k（qj）+e*sin（Et_1（qj））;????????
??????????????delta_E（qj）=Et（qj）-Et_1（qj）;
??????????????Et_1（qj）=Et（qj）;
??????????????if?abs（delta_E（qj））<=1.0e-6
?????????????????E_k（qj）=Et（qj）;??
?????????????????t_end=0;
??????????????end?
??????????end?
???????%%%%%%%%%%%%%%?求真近點角?f?的值?%%%%%%%%%%
??????????%A=（cos（E_k（qj））-e）/（1-e*cos（E_k（qj）））;??????????%%?f?的余弦
??????????A=cos（E_k（qj））-e;???????????????%分母一定是是大于0的數所以只取分子來做判斷
??????????%B=（sin（E_k（qj））*sqrt（1-e^2））/（1-e*cos（E_k（qj）））;%%?f?的正弦
??????????B=sqrt（1-e^2）*sin（E_k（qj））;

?????????if?（A==0）
?????????????f（qj）=pi/2;????

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????7760??2008-01-09?15:24??GPS\gps_constellation_emluator\gps_constellation_emluator.m

?????文件???????3241??2007-12-06?21:41??GPS\gps_constellation_emluator\gps_satellite_distribute.m

?????文件???????8488??2007-12-06?21:37??GPS\gps_constellation_emluator\gps_satellite_distribute1.fig

?????文件???????8488??2007-12-06?21:41??GPS\gps_constellation_emluator\gps_satellite_distribute2.fig

?????文件???????8392??2007-12-06?21:41??GPS\gps_constellation_emluator\gps_satellite_distribute3.fig

?????文件???????9528??2007-12-04?14:01??GPS\gps_constellation_emluator\PDOP_Value.fig

?????文件??????10896??2007-12-04?14:01??GPS\gps_constellation_emluator\Plane_Orbit.fig

?????文件??????11896??2007-12-04?14:00??GPS\gps_constellation_emluator\Space_Orbit.fig

?????文件???????8464??2007-12-04?14:00??GPS\gps_constellation_emluator\visible_satellite.fig

?????目錄??????????0??2007-12-06?21:42??GPS\gps_constellation_emluator

?????文件??????15048??2008-03-26?17:03??GPS\gps_kalman\gps_kalman.m

?????目錄??????????0??2008-03-24?09:52??GPS\gps_kalman

?????文件??????13279??2007-12-08?21:05??GPS\gps_kalman_zsy\gps_kalman_zsy.m

?????目錄??????????0??2007-12-06?15:11??GPS\gps_kalman_zsy

?????文件??????12756??2008-03-22?09:38??GPS\gps_position\gps_position.m

?????目錄??????????0??2008-03-22?09:10??GPS\gps_position

?????文件??????19446??2008-01-16?15:03??GPS\read_data\brdc3330.07n

?????文件??????19446??2008-01-16?15:26??GPS\read_data\brdc3470.07n

?????文件???????1421??2008-01-16?15:13??GPS\read_data\eph.dat

?????文件???????1421??2008-01-16?15:28??GPS\read_data\eph1.dat

?????文件???????1132??2008-01-16?15:28??GPS\read_data\Read_eph.m

?????目錄??????????0??2008-01-16?15:28??GPS\read_data

?????目錄??????????0??2008-03-21?21:32??GPS

-----------?---------??----------?-----??----

???????????????161320????????????????????24