根据广播星历计算卫星坐标的matlab代码

以下是根据广播星历计算卫星坐标的Matlab代码示例：

function [sv_xyz, sv_clk] = get_satellite_pos(t,eph)

% t: 当前时间
% eph: 广播星历数据
% sv_xyz: 卫星坐标（x, y, z）
% sv_clk: 卫星钟差

GM = 3.986005e14; % 地球万有引力常数
OMEGA_E_DOT = 7.2921151467e-5; % 地球自转角速度

% 计算卫星时钟误差
a0 = eph.af0;
a1 = eph.af1;
a2 = eph.af2;
t_oc = eph.toc;
dt = t - t_oc;
sv_clk = a0 + a1 * dt + a2 * dt^2;

% 计算卫星位置
a = eph.sqrt_a^2;
n0 = sqrt(GM/a^3);
n = n0 + eph.delta_n;
M = eph.m0 + n * dt;
E = M;
for i = 1:10
E_old = E;
E = M + eph.e * sin(E_old);
if abs(E - E_old) < 1e-12
break;
end
end
v = atan2(sqrt(1 - eph.e^2) * sin(E), cos(E) - eph.e);
phi = v + eph.omega;
delta_u = eph.cus * sin(2 * phi) + eph.cuc * cos(2 * phi);
delta_r = eph.crs * sin(2 * phi) + eph.crc * cos(2 * phi);
delta_i = eph.cis * sin(2 * phi) + eph.cic * cos(2 * phi);
u = phi + delta_u;
r = a * (1 - eph.e * cos(E)) + delta_r;
i = eph.i0 + eph.idot * dt + delta_i;
x = r * cos(u);
y = r * sin(u);
OMEGA = eph.omega0 + (eph.omega_dot - OMEGA_E_DOT) * dt - OMEGA_E_DOT * eph.tgd;
sv_xyz = [x * cos(OMEGA) - y * cos(i) * sin(OMEGA); x * sin(OMEGA) + y * cos(i) * cos(OMEGA); y * sin(i)];
end