When the input-offset vector is parallel
to the output-offset vector ,
the triangle --, formed
by the midpoints of the input trace, zero-offset trace, and output
trace, degenerates to a line. The location of the zero-offset midpoint
is not constrained by the input and output midpoints and can
take different values on the line. The cascade of DMO and inverse DMO
becomes a convolution on that line. To find the summation path of 2-D
AMO (offset continuation), one needs to consider the envelope of the
family of traveltime curves (where *m _{0}* is the parameter of a
curve in the family):

(49) |

(50) |

11/11/1997