1subroutine geocentric(alat,elev,hlt,erad) 2 3 implicit real*8 (a-h,o-z) 4 5! IAU 1976 flattening f, equatorial radius a 6 f = 1.d0/298.257d0 7 a = 6378140.d0 8 c = 1.d0/sqrt(1.d0 + (-2.d0 + f)*f*sin(alat)*sin(alat)) 9 arcf = (a*c + elev)*cos(alat) 10 arsf = (a*(1.d0 - f)*(1.d0 - f)*c + elev)*sin(alat) 11 hlt = datan2(arsf,arcf) 12 erad = sqrt(arcf*arcf + arsf*arsf) 13 erad = 0.001d0*erad 14 15 return 16end subroutine geocentric 17 18