gravity.m

惯性导航系统传递对准系统模型程序

function g = gravity(lat,height)

   if nargin<2,error('insufficient number of input arguments'),end
   
   h = height;
   [Rm,Rp] = radicurv(lat);
   Ro = sqrt(Rp*Rm);   % mean earth radius of curvature
   g0 = 9.780318*( 1 + 5.3024e-3*(sin(lat))^2 - 5.9e-6*(sin(2*lat))^2 );
   if h >= 0,
      g = g0/( (1 + h/Ro)^2 );
   end
   if h < 0,
      g = g0*(1 + h/Ro);
   end,
   if h < -Ro,
      error(' Input altitude is less than -(earth radius) ')
   end,