In the discussion above,
events were assumed to be either in the null space of an operator
or not.
In general, an operator will attenuate an event to some extent.
The null space of an operator is completely attenuated,
while other events are partially attenuated, depending on the
situation in which the filter is designed.
Operators derived from real seismic data are unlikely to
perfectly predict either signal or noise.
Events that are simply attenuated by the signal filter
and
the noise filter
will be distributed between the calculated
signal
and the calculated noise
depending on the relative attenuation
of
and
.