Abstract
Appropriate restriction of a migration aperture decreases migration noise of a seismic migration method. The Fresnel volume migration chooses the migration aperture considering the Fresnel volume of the received elastic wave. The Fresnel volume is regarded as the energy propagation space and determined by the propagating wave frequency and the incident angle to the receiver. Robust estimation of the Fresnel volume position leads to robust migration aperture restriction. Thus, estimation of the incident angle with maximum accuracy enhances signal to noise ratio of the Fresnel volume migration result.
In recent researches, some Fresnel volume migration methods estimate incident angles using three components slowness vectors in TSP, VSP, etc. Other methods estimate incident angles by analyzing the correlation of one component sensors for surface seismic data. Though, these method may miss-choose incident angles either when signal to noise ratio does not reach to estimate and when analyzing sensor receives several waves at the same time.
In this study, we used τ-p transforms to estimate incident angles stably even in such cases. We applied the Fresnel volume migration using τ-p transforms to 2D simulation data of point and slope model. As the result, we find that two methods are robust methods to use for the Fresnel volume migration. Also, comparing with slowness vector method, τ-p transform estimation can restrict migration aperture more stably.
