b'Seismic window Figure 6.Spectral Decomposition of a single 20 m thick bed. The peak amplitude at 25 Hz (*) successfully predicts the bed thickness. The short window FFT +-14 ms also has a peak amplitude at 25 Hz howeverFigure 9.Illustration of four bed model and frequencies below 20 Hz are attenuated and poorly estimated because the window length of the FFT is too short. combination of beds that give rise to multiple possible bed thicknesses. A35 m gross thickness, B25 m and C15 m. All these cases involve the top of a bed and the bottom of a bed but only in case D is it the same bed.AcknowledgmentOpendTect donated all software used to generate the figures in this article.Figure 7.Spectral Decomposition of a model with two 10 m beds separated by 10 m. Here the 10 m bed thickness can be estimated from the frequency at point F (~50 Hz). An interesting aspect is the high amplitude anomaly at point E (~17 Hz) which corresponds to the thickness of the gross interval (30 m).Figure 8.NOTE change of scale. This model has four beds 5 m thick with 5 m between each bed. The response not only includes the 5 m beds (D) but also the various combinations A, B and C. These correspond to gross thicknesses of 35 m, 25 m and 15 m respectively as shown in Figure 9.DECEMBER 2021 PREVIEW 52'