Patent ID: 6272444
Filing Date: 2001-08-07
Classification: G01V

Abstract:
Method of characterizing the coherence of measurements made in a given medium, comprising the steps of:taking N types of reference measurements at each point (P.sub.i) of a given reference set of said medium, each point (P.sub.i) being defined by a depth dimension, the group of N measurements which are associated with each point (P.sub.i) constituting a reference observation (X.sub.i),forming at least one N-dimensional learning set containing all the points (P.sub.i),taking at least N application measurements at each point (Q.sub.i) of an application set of the medium, which is different from the reference set, each group of application measurements which are associated with the point (Qi) constituting an application observation (x),comparing each application observation (x) with all the reference observations (X.sub.i) of the learning set,constructing a neighbourhood domain (D.sub.i) for each reference observation (X.sub.i) of the learning set using the k nearest neighbours process (K-NN), said neighbourhood domains constituting the learning set which defines an acceptance class (C.sub.a) for application observations (x) in the application set, anddefining a degree of membership of the application observations (x) to the acceptance class (C.sub.a), each application observation (x) being assigned to the acceptance class (C.sub.a) when its membership degree is at least greater than a first threshold (S.sub.1).