it2.m

迭代实现非线性函数（电离层延迟模型）的参数拟合问题

function delay=It2(A1,B,alpha0,alpha1,alpha2,alpha3,beta0,beta1,beta2,beta3,gama0,gama1,gama2,gama3,t,fm)

A2=a2(alpha0,alpha1,alpha2,alpha3,fm);
A3=a3(gama0,gama1,gama2,gama3,fm);
A4=a4(beta0,beta1,beta2,beta3,fm);
DC=dc(A1,B,t); 
if   (21600<t)&(t<72000);
    delay=5+A1+B*(t-72000)+A2*cos(2*pi*(t-A3)/A4);
else delay=DC;
end