1. Moveout-Based Spreading Correction for Mode-Converted Waves Ellen (Xiaoxia) & Ilya

2. Moveout-Based Geometrical Spreading P S

3. VTI Model

4. Nonhyperbolic Moveout Equations Tsvankin & Thomsen (1994) Alkhalifah and Tsvankin (1995)

5. Accuracy of MASC with η-Equation Offset/Depth 1 2 6 5 4 3 Spreading (km) Ray tracing MASC

6. CMP Gather Time (s) 1.0 2.0 3.0 Offset (km) 0 12 3 PP PS SS

7. Processing Flow  pick amplitude  correct for source and receiver directivity  correct for geometrical spreading  calibrate amplitude

8. Comparison of Conversion Coefficients Horizontal slowness (s/km) 0.1 0.2 0.3 0.0 -0.1 -0.2 Exact MASC t 2 -gain

9. Transmission Loss 0.0 0.1 0.2 0.3 Horizontal slowness (s/km) -0.05 0.00 0.05 0.10 0.15

10. Moveout Equation in ORTH Media

11. Orthorhombic Model x1x1 x3x3 ISO x2x2

12. Spreading (km) Offset (km) 0 1 2 3 3 6 5 4 azimuth 90 o azimuth 0 o Accuracy of MASC with η-Equation

13. VTI/ORTH Model x1x1 x3x3 VTI ISO x2x2

14. Spreading (km) Offset (km) 0 1 2 3 3 6 5 4 azimuth 90 o azimuth 0 o Accuracy of MASC with η-Equation

15. Conclusions  same algorithm for PP and PSV  accuracy of η-equation for PSV lower than for PP  important for AVO analysis

16. Tilted Transversely Isotropic (TTI) Model

17. Traveltime Surface for TTI layer 0 1 2 -2 Traveltime (s) 1.0 1.1 1.2 1.3 1.4 X (km) Y (km)

18. Accuracy of MASC Offset (km) 0 1 2 3 -2-3 2 3 4 5 Spreading (km) MASC Ray tracing

19. Future Work Jonah field data application

20. Layered VTI Model ISO

22. Layered ORTH Media (aligned )

23. Layered ORTH Media (misaligned)

24. Generic equation of geometrical spreading Červený (2001)