|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).