We present a target-oriented version of least squares migration (LSM). A small target region of the model is defined, and the associated target data are identified by Kirchhoff modeling. The target data are much smaller in size than the original data. These data are migrated in the least squares sense to obtain the reflectivity, but the computational cost is significantly reduced due to a smaller data set and target size. Results with UNOCAL's poststack marine data show the LSM images to be noticeably more focused compared to Kirchhoff migration images. In addition, use of the migration deconvolution image as a starting model improves the ability of LSM to focus seismic energy. An important implication is that target-oriented LSM might be as affordable as standard Kirchhoff migration.
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology