!
!@cobsn.i
!
      Integer*4 Nzero
      COMMON / OBSRVN / Nzero
!  Mods:
!     98.07.29 - D. Gordon  Include file and comon block created.
!
!       1. Nzero   -  Set equal to 1 or 2 if station 1 or 2 is at the geocenter.
!                     Otherwise zero.