  We develop mathematical methods which allow us to study asymptotic properties
of solutions to the three dimensional Navier-Stokes system for incompressible
fluid in the whole three dimensional space. We deal either with the Cauchy
problem or with the stationary problem where solutions may be singular due to
singular external forces which are either singular finite measures or more
general tempered distributions with bounded Fourier transforms. We present
results on asymptotic properties of such solutions either for large values of
the space variables (so called the far-field asymptotics) or for large values
of time.
