XMM-Newton Science Analysis System


ssclib (ssclib-4.33) [xmmsas_20190531_1155-18.0.0]

skyToCartesian

  interface skyToCartesian
    function skyToCartesianSingle(ra, dec) result(vector)
      real(single), intent(in) :: ra, dec 
      real(single)             :: vector(3)
    end function skyToCartesian

    function skyToCartesianDouble(ra, dec) result(vector)
      real(double), intent(in) :: ra, dec 
      real(double)             :: vector(3)
    end function skyToCartesian
  end interface

Returns a vector of direction cosines of the celestial coordinates $ra$ and $dec$. NOTE $ra$ and $dec$ must be in radians.