  Gravitational radiation plays an important role in astrophysics. Based on the
fact that our universe is expanding, the gravitational radiation when a
positive cosmological constant is presented has been studied along with two
different ways recently, one is the Bondi-Sachs (BS) framework in which the
result is shown by BS quantities in the asymptotic null structure, the other is
the perturbation approach in which the result is presented by the quadrupoles
of source. Therefore, it is worth to interpret the quantities in asymptotic
null structure in terms of the information of the source. In this paper, we
investigate this problem and find the explicit expressions of BS quantities in
terms of the quadrupoles of source in asymptotically de Sitter spacetime. We
also estimate how far away the source is, the cosmological constant may affect
the detection of the gravitational wave.
