r sqrt(x^2+y^2) "Radial coordinate in the xy-plane"
theta atan2(y,x) "Azimuthal angle in the xy-plane"
dx x-dest(x) "Displacement from destination to source, x-coordinate"
dy y-dest(y) "Displacement from destination to source, y-coordinate"
dz z-dest(z) "Displacement from destination to source, z-coordinate"
dxn sqrt(dx^2+dy^2+dz^2) "Distance from destination to source"
dxcn sqrt(x^2+y^2+z^2) "Distance from receiver center to source"
delta acos((dx*x+dy*y+dz*z)/(dxn*dxcn)) "Solar angle of incoming rays"
fd 1000[W/m^2]/(pi*sin(4.65[mrad])^2)*(delta<4.65[mrad]) "Radiant intensity"
theta1 acos((dx*nx+dy*ny+dz*nz)/dxn) "Angle between reflected ray and normal, dish"
theta2 acos((dx*dest(nx)+dy*dest(ny)+dz*dest(nz))/dxn) "Angle between reflected ray and normal, target"
cr intop1(fd*cos(theta1)*cos(theta2)/dxn^2)/1[kW/m^2] "Idealized concentration ratio, Jeter"