Application of the normalized total gradient (NTG) method to calculate envelope of seismic reflection signals


JOURNAL OF APPLIED GEOPHYSICS, vol.71, pp.90-97, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 71
  • Publication Date: 2010
  • Doi Number: 10.1016/j.jappgeo.2010.05.002
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.90-97
  • Keywords: Analytical signal, Fourier sine series, Normalized total gradient, Resolution, Smoothness, FULL GRADIENT, GRAVITY-ANOMALIES, BODIES
  • Karadeniz Technical University Affiliated: Yes


In interpretation of seismic data the resolution and smoothness of the envelope of the seismic trace is an important property to have. This paper introduces a new method of envelope generation for seismic traces that is based on the concept of normalized total gradient (NTG) that found many useful applications in interpretation of potential field data and is considered in that field of study to be better resolved and smoother than envelopes obtained using the well known complex trace concept based on Hilbert transform. The NTG method defines a seismic trace by finite Fourier sine series. It then converts the seismic trace into an analytical trace in a manner similar to complex seismic trace analysis. As this trace is made of partial derivatives of a new function defined from the trace itself it is indeed a gradient vector and its envelope is therefore called "total gradient". The division of the total gradient by its average over time forms the "normalized total gradient" (NTG).