Inverse NS convolution: | ((120)) | |

Inverse NS combination: | ((121)) | |

Adjoint inverse NS convolution: | ((122)) | |

Adjoint inverse NS combination: | ((123)) | |

As with the stationary inverse convolution described above, it is apparent that subject to numerical errors, non-stationary inverse filtering with these equations in Table 1 is the exact, analytic inverse of non-stationary filtering with the corresponding forward operator described in equations () through (): they are true inverse processes. If operator represents filtering with a non-stationary causal-filter, and represents recursive inverse filtering with the same filter then

The `nhelicon` module Claerbout (1998a) implements the
non-stationary combination operator/adjoint pair, described by
equations () and (), while
`npolydiv` implements the corresponding inverse operators,
described by equations (A.10)
and (A.12).

5/27/2001