| Abstract Submission No. | ABS-4.1-0197 |
| Title of Abstract | Amplitude Compensated Laplacian Filtering for suppression of the Low-Frequency Artifacts in RTM imaging |
| Authors | Raju Babu Allu*, Dr. Laxmidhar Behera |
| Organisation | CSIR-National Geophysical Research Institute |
| Address | Room No 121, CSS and Gas Hydrates Section, CSIR-NGRI, Habsiguda. Hyderabad, Telangana, India Pincode: 500007 E-mail: allu.ngri21j@acsir.res.in |
| Country | India |
| Presentation | Oral |
| Abstract | Reverse time migration (RTM) with zero lag cross-correlation imaging is commonly employed for subsurface reflector imaging, however it frequently produces low-frequency artifacts due to direct arrivals, backscattering, and diving waves, reducing image clarity and interpretability. To reduce these artifacts, we use a Laplacian filter, a second-order derivative operator that is good for edge enhancement and low-frequency suppression. However, direct application of Laplacian filtering may affect reflection amplitudes and wavelet integrity. As a result, we use an amplitude-compensated Laplacian filtering approach that first normalizes the migrated image with a source-derived compensation factor. Our proposed workflow includes three important steps: 1. Create the initial RTM image using zero lag cross correlation of the source and receiver wave fields. 2. Create a compensation map based on the source illumination energy with wavelet amplitude. 3. Apply the Laplacian operator to the corrected image. This method effectively reduces low-wavenumber noise while maintaining reflection fidelity. We test the strategy using both benchmark synthetic models and field seismic data. The results show clearer reflector delineation, fewer artifacts, and better preservation of amplitude characteristics, beating both unfiltered RTM and naive Laplacian filtering. The suggested technique improves image resolution and interpretability in difficult geological contexts while incurring little additional computing costs. |
| Keywords | reverse time migration, cross correlation imaging, Laplacian filter, amplitude compensation, low frequency artifact suppression, seismic imaging. |