1. Determining location with diffraction propagation Micah Taylor 2008-10-13 http://kixor.net/school/2008fall/comp790/project/

2. Localization

3. Finding location relative to wave source

4. Localization Finding location relative to wave source –Cell phones

5. Localization Finding location relative to wave source –Cell phones –GPS

6. Localization Finding location relative to wave source –Cell phones –GPS –Much work in robotics

7. Types of propagation

8. RF propagation Direct –From source to receiver –Strongest

9. RF propagation Direct –From source to listener –Strongest Reflection –Bounces off things –Multipath

10. RF propagation Direct –From source to listener –Strongest Reflection –Bounces off things –Multipath

11. RF propagation Direct –From source to listener –Strongest Reflection –Bounces off things –Multipath Diffraction –Travel around buildings –Multipath

12. Diffraction

13. Bending around objects

14. Diffraction Bending around objects Allows out of LOS paths

15. Diffraction Bending around objects Allows out of LOS paths

16. Diffraction Bending around objects Allows out of LOS paths Very important for signal in cities!

17. Diffraction research

18. Huygens’ diffraction

19. Diffraction research Huygens’ diffraction

20. Diffraction research Huygens’ diffraction Several models

21. Diffraction research Huygens’ diffraction Several models –Huygens-Kirchhoff –Fresnel –GTD –UTD –BTM

22. Frustum tracing

23. No complicated wave effects

24. Frustum tracing No complicated wave effects Uses geometry to estimate propagation

25. Frustum tracing No complicated wave effects Uses geometry to estimate propagation Models propagation

26. Frustum tracing No complicated wave effects Uses geometry to estimate propagation Models propagation –Stronger in LOS –Bounces

27. Frustum tracing No complicated wave effects Uses geometry to estimate propagation Models propagation –Stronger in LOS –Bounces Discrete volumes

28. Advantages

29. Very fast

30. Advantages Very fast Supports moving objects

31. Advantages Very fast Supports moving objects Different materials

32. Advantages Very fast Supports moving objects Different materials Convincing results

33. Advantages Very fast Supports moving objects Different materials Convincing results Runs on ordinary PC

34. Other work

35. Raytracing

36. Other work Raytracing –Dynamic/complex scenes –Slow and aliases

37. Other work Raytracing –Dynamic/complex scenes –Slow and aliases

38. Other work Raytracing –Dynamic/complex scenes –Slow and aliases Beam tracing

39. Other work Raytracing –Dynamic/complex scenes –Slow and aliases Beam tracing –Fast without aliasing –Static/simple scenes

40. Other work Raytracing –Dynamic/complex scenes –Slow and aliases Beam tracing –Fast without aliasing –Static/simple scenes

41. Other work Raytracing –Dynamic/complex scenes –Slow and aliases Beam tracing –Fast without aliasing –Static/simple scenes Frustum tracing

42. Other work Raytracing –Dynamic/complex scenes –Slow and aliases Beam tracing –Fast without aliasing –Static/simple scenes Frustum tracing –Some aliasing

43. Goals

44. Combine RF diffraction with frustum tracing

45. Goals Combine RF diffraction with frustum tracing Find possible paths through environment

46. Goals Combine RF diffraction with frustum tracing Find possible paths through environment Attempt localization using path attenuation