During marine seismic surveys for oil and gas,offshore platforms,shipping traffics,barriers on the sea floor and
discontinuous topography can cause point source diffracted noises with strong energy.The diffracted noises seriously
affect the seismic imaging,which is one of the difficulties in noise suppressing for marine seismic data
processing.Based on the production mechanism and time-distance equation of the diffracted noise,we studied
attenuation methods for linear and hyperbolic point source diffracted noises.The linear diffracted noise attenuation
is conducted by predicted filtering in f-x domain by linear noise analysis,discrimination,fitting and
subtraction.The hyperbolic diffracted noise is simulated on time-distance equation and point source positions
predicted by similarity scanning,and matched modeling diffracted noise from the predicted point source with field
data by matching filtering.Then it is subtracted from field data.We tested the methods on model data and field
data.The results show that the new methods can attenuate point source diffracted noises effectively with good
amplitude preservation.