On the estimation of local slopes

Abstract

Conventional semblance methods can be avoided for a number of imaging tasks if local slopes can be directly extracted from prestack data, for example, by filtering schemes. Recent literature shows a revival of the idea for various purposes, such as velocity analysis, tau-p imaging, migration to zero offset and time migration. Here, we discuss several different ways of extracting the desired slope information from the data. We propose a simple, straightforward correction to linear plane-wave destructors. The correction is based on the observation that additionally to the local slope, also its inverse can be extracted from the data in a fully analogous way. Combining the information of both extractions yields a simple but powerful correction to the local slopes. In our numerical examples, the naive application of simple linear plane-wave destructors with our simple, straightforward correction produced results of high quality, even in an example with a rather high noise level and interfering events.

Conventional semblance methods can be avoided for a number of imaging tasks if local slopes can be directly extracted from prestack data, for example, by filtering schemes. Recent literature shows a revival of the idea for various purposes, such as veloci