www.pudn.com > ld.rar > projection_parameter.m, change:2008-12-23,size:773b


function [alpha K Ps] = projection_parameter(phi_S,phi_N,phi_0,A,E);%%投影参数计算 
 
phi_1 = phi_S + ((phi_N - phi_S)/4.0); 
phi_2 = phi_N - ((phi_N - phi_S)/4.0); 
 
rad_0 = phi_0 * pi/180; 
rad_1 = phi_1 * pi/180; 
r1 = A * cos(rad_1) / sqrt(1-(E*sin(rad_1)*E*sin(rad_1))); 
rad_2 = phi_2 * pi/180; 
r2 = A * cos(rad_2) / sqrt(1-(E*sin(rad_2)*E*sin(rad_2))); 
 
u_0 = log(tan(pi/4.0 + rad_0/2.00)) + (E/2.0) * (log((1-E*sin(rad_0))/(1+E*sin(rad_0)))); 
u_1 = log(tan(pi/4.0 + rad_1/2.0)) + (E/2.0) * (log((1-E*sin(rad_1))/(1+E*sin(rad_1)))); 
u_2 = log(tan(pi/4.0 + rad_2/2.0)) + (E/2.0) * (log((1-E*sin(rad_2))/(1+E*sin(rad_2)))); 
 
alpha = ( log(r1) - log(r2) ) / ( u_2 - u_1 );	 
K     = exp( log(r1) + alpha*u_1 - log(alpha) ); 
Ps    = exp( log(K) - (alpha)*u_0 );