EPB Function

  1. astro_module.f90
  2. astro_module
  3. EPB

public function EPB(dj1, dj2) result(res)

Julian Date to Besselian Epoch.

Status: support routine.

Note

The Julian Date is supplied in two pieces, in the usual SOFA manner, which is designed to preserve time resolution. The Julian Date is available as a single number by adding DJ1 and DJ2. The maximum resolution is achieved if DJ1 is 2451545D0 (J2000.0).

Reference

  • Lieske, J.H., 1979, Astron.Astrophys. 73, 282.

History

  • IAU SOFA revision: 2013 August 7

Arguments

TypeIntentOptionalAttributesName
real(kind=wp), intent(in) :: dj1

Julian Date (see note)
real(kind=wp), intent(in) :: dj2

Julian Date (see note)

Return Value real(kind=wp)

the Besselian Epoch


Contents

Source Code

EPB

Source Code

    function EPB ( dj1, dj2 ) result(res)

    implicit none

    real(wp),intent(in) :: dj1 !! Julian Date (see note)
    real(wp),intent(in) :: dj2 !! Julian Date (see note)
    real(wp) :: res !! the Besselian Epoch

    !  J2000.0 minus B1900.0 (2415019.81352) in days
    real(wp),parameter :: d1900 = 36524.68648_wp

    !  Length of tropical year B1900 (days)
    real(wp),parameter :: ty = 365.242198781_wp

    res = 1900.0_wp + ( ( dj1-dj00 ) + ( dj2+d1900 ) ) / ty

    end function EPB