1. Trondheim Tekniske Fagskole The “Design Wave Philosophy’’ Calculation of the design wave Wave forces on semi-submersible platforms Wave forces and bending moments in FPSO-ships Platform movements in large waves Examples of heavy weather damage What is a Rogue Wave ? Why, where and when ? Shall we design against Rogue and Freak Waves ? What can a platform master do against Rogue and Freak Waves ? *****Remote-sensing of sea conditions ***** Search And Rescue and emergency operations Decision making in an emergency Remote-Sensing of Sea Conditions

2. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions

3. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions Satellite measurements Merging remote-sensing and forecasts Comkiss and Cammeo projects results Remote-sensing and rogue waves

4. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions Satellites can measure many ocean parameters: colour,

5. Trondheim Tekniske Fagskole Waves,

6. Trondheim Tekniske Fagskole Effects of bathymetry on ocean surface,

7. Trondheim Tekniske Fagskole Wind,

8. Trondheim Tekniske Fagskole How can a satellite measure waves ? Remote-Sensing of Sea Conditions A side-product of the altimeter noise, or A side-product of the imaging synthetic aperture radar. Keep in mind that the sensors were designed for other purposes than wave measurement

9. Trondheim Tekniske Fagskole Altimeter Remote-Sensing of Sea Conditions

10. Trondheim Tekniske Fagskole

12. Scatterometer Remote-Sensing of Sea Conditions

13. Trondheim Tekniske Fagskole Synthetic aperture radar (SAR) Remote-Sensing of Sea Conditions

14. Trondheim Tekniske Fagskole Synthetic aperture radar (SAR) Remote-Sensing of Sea Conditions

15. Trondheim Tekniske Fagskole Synthetic aperture radar (SAR) Remote-Sensing of Sea Conditions

16. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions

17. Trondheim Tekniske Fagskole Some problems: Altimeter returns are noisy Altimeter return signal is lower when winds are higher Scatterometer winds require model “first guess” to get the direction.

18. Trondheim Tekniske Fagskole Problem: One does not get a measurement where and when it would be needed

19. Trondheim Tekniske Fagskole Problems: SAR inversion is a complex process, no unique solution, and requiring a first guess. SAR imagettes are frequently unusable SAR misses all waves below 45m wavelength and some longer ones in the azimuth direction

20. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions Satellite measurements Merging remote-sensing and forecasts Comkiss and Cammeo projects results Remote-sensing and rogue waves

21. Trondheim Tekniske Fagskole Problem: It takes several hours to retrieve the data from the satellite process them validate them make them available to service providers In addition, ESA would like to make money out of them, so the question arises of what improvement over conventional forecasts ? Measurements w.r.t. Forecasts

22. Trondheim Tekniske Fagskole An example: San Francisco-Guam cable laying Measurements w.r.t. Forecasts

23. Trondheim Tekniske Fagskole An example: San Francisco-Guam cable laying Measurements w.r.t. Forecasts

24. Trondheim Tekniske Fagskole Agreement: service of little use to shipmaster Measurements w.r.t. Forecasts

25. Trondheim Tekniske Fagskole Disagreement: Measurements w.r.t. Forecasts

26. Trondheim Tekniske Fagskole Warning Measurements w.r.t. Forecasts

27. Trondheim Tekniske Fagskole Conclusions: Warning was not fetched and thus arrived too late Sending forecasts and corrections to them is not a good option, one should rather send the best forecast possible Measurements w.r.t. Forecasts

28. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions Satellite measurements Merging remote-sensing and forecasts Comkiss and Cammeo projects results Remote-sensing and rogue waves

29. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions Other Comkiss and Cammeo projects results: Several reliable sources provide surface currents Several reliable sources provide wave climate databases (DNV has pushed to acceptance of satellite databases for design) Improvement of the databases used for fatigue http://www.ifremer.fr/metocean/shipping/shipping.html

30. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions Other Comkiss and Cammeo projects results: High Speed Crafts operations (and thus offshore operations too) planning and conducting are not significantly improved. Forecast enhancement from satellite as well as from platform motion measurements is not yet mature. http://www.ifremer.fr/metocean/shipping/shipping.html

31. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions Satellite measurements Merging remote-sensing and forecasts Comkiss and Cammeo projects results Remote-sensing and rogue waves

32. Trondheim Tekniske Fagskole Remote-Sensing of Sea Conditions Some scientists claim that they can see rogue waves on SAR images or imagettes.

33. Trondheim Tekniske Fagskole One should be aware that: SAR measurements, on the opposite to altimeter ones, show a great deal of uncertainty on Hs

34. Trondheim Tekniske Fagskole uncertainty on the individual wave height measured by a satellite is very high

35. Trondheim Tekniske Fagskole the maximum wave height over an area is theoretically higher than when observing waves passing by a fixed point

36. Trondheim Tekniske Fagskole Altimeter measurements of Hs are reliable Wind measurements are reliable, except in extreme conditions Forecast enhancement from satellite data is not yet mature Rogue wave detection is still a topic for academic research. Conclusions