## 4 Results and Discussion
### Spectrum Decomposition Comparison  
For the 15-50 Hz range, the seismic data volume was decomposed by spectral decomposition [36; 37; 38], using a 5 Hz step size. The spectral decomposition data volumes for different frequencies were obtained, together with the corresponding attribute slices along the layer spectral decomposition (Figure 14). For the same layers, the spectral decomposition slices of different frequencies were highly consistent overall but showed different energy intensities. From low to high frequencies, the energy range became more concentrated, and the anomaly became more obvious. The low energy part of the slice map, visible after high frequency spectrum decomposition, represents the abnormal body. Figure 14 shows obvious anomalies for the goat in the 45 Hz and 15 Hz areas of the coal seam #3. We digitized and standardized the logging data and synthesized the seismic records by integrating the logging data with the seismic data. This process was used to calibrate the target #3 and #15 coal seams. High-quality seismic data from Well 163 was selected to analyze the seismic wavelet statistics and synthesize the seismic records (Figure 15). The #3 and #15 coal seam intervals correspond to the negative phase positions at 420 ms and 480 ms on the seismic trace, respectively. Figure 13: Goal boundary in the conventional profile (**a**), in the conventional frequency lifting profile (**b**), in the OVT treatment profile (**c**), and in the OVT treatment frequency lifting profile (**d**). Figure 14: Installing amplitude slicing along the spectra obtained for coal seam #3 (**a**\(-\)15 Hz, **b**\(-\)20 Hz, **c**\(-\)25 Hz, **d**\(-\)30 Hz, **e**\(-\)35 Hz, **f**\(-\)40 Hz, **g**\(-\)45 Hz, **h**\(-\)50 Hz). Figure 15: Synthetic Seismic Record and Horizon Correlation for Well 163. By converting the well logs with pseudo-velocity curves into a velocity-depth relationship, we obtained the time-depth relationship for the study area. Due to the significant differences in rock properties (density and p-wave velocity) between the coal seams and the surrounding strata, the interfaces at the top and bottom of the coal seams were identified as locations where the reflection coefficient reaches its maximum absolute value (Figure 16). During the time-depth conversion, we used the average velocity calculated from the well side tracks to correct the average velocity field. This correction enhances the accuracy of the velocity field, thereby improving the overall precision of the time-depth conversion. The typical seismic profile of the sixth mining area (Figure 17), from top to bottom, shows the reflection wave of coal seam #3, the reflection wave of coal seam #15, and the top interface of Ordovician limestone. The reflection waves of coal seams #3 and #15 are evident in the profile, and the continuity of the whole area is good; moreover, the reflection wave of the Ordovician limestone top interface is strong and continuous in the whole area. Coal seam #3 was mined out on the right side of the seismic profile, resulting in a goaf. At the boundary between normal coal and the goat, the in-phase axis of coal seam #3 obviously changes from strong to weak, and there is an obvious time difference. The energies reflected by coal seam #15 and by the Ordovician limestone top interface are not much different, but the horizon time is obviously larger. In the 45-Hz spectral decomposition profile (Figure 17b), there is an obvious energy loss zone between the goat and the normal coal seam, which directly indicates the location of the goat boundary. To analyze the boundary of the goaf in the roadway, drilling depth, seismic data processing for dynamic correction velocity calculation of layer velocities and average velocities are employed to form a velocity field in spatial positions. After time-depth conversion, the coal seam roof and the ground elevation are obtained, forming a planar distribution. Along  
Figure 16: Characteristics of Major Coal Seams on the Seismic Profile.