init_antenna_data Subroutine

  subroutine init_antenna_data (nk_stir)
    integer, intent (in) :: nk_stir

! do not reallocate this array on this processor...

    if (initialized) return
    initialized = .true.

    ant_on = nk_stir > 0
    if (.not. ant_on) return
    allocate (a_ant(nk_stir), b_ant(nk_stir))
  end subroutine init_antenna_data