pro sam_pix_to_ab,r0,theta,alpha=alpha,beta=beta alpha=dblarr(320,240) beta=dblarr(320,240) if n_elements(r0) eq 0 then r0=[164.5,120.6,-21200] if n_elements(theta) eq 0 then theta=!dtor*15.5d ;Figure the image matrix n=[sin(theta),0,cos(theta)] nx=n[0] ny=n[1] nz=n[2] mx=0 my=1 mz=-my*ny/nz m=[mx,my,mz] m/=norm(m) p=crossp(m,n) A_r2i=[[P],[M],[N]] A_i2r=transpose(A_r2i) for i=0,319 do begin for j=0,239 do begin r_i=[i,j,0] r_r=A_i2r ## r_i rt=r_r-r0 alpha[i,j]=-atan(rt[0]/rt[2]) beta[i,j]=atan(rt[1]/rt[2]) end end ;Convert radians to arcmin alpha=alpha*60d*180d/!dpi beta=beta*60d*180d/!dpi end