Determining location with diffraction propagation

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

2. Localization

3. Localization • 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. Diffraction • 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 signalin cities!

17. Diffraction research

18. Diffraction research • 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. Frustum tracing • 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. Advantages • 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. Other work • 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. Goals • Combine RF diffractionwith frustum tracing

45. Goals • Combine RF diffractionwith frustum tracing • Find possible paths throughenvironment

46. Goals • Combine RF diffractionwith frustum tracing • Find possible paths throughenvironment • Attempt localization usingpath attenuation