This document describes a system for interpolating and visualizing PM2.5 data based on wind fields. It discusses capturing PM2.5 and wind data from various sources, using wind data to interpolate sparse PM2.5 readings, and rendering the results in a web-based 3D interactive visualization using techniques like streamlines and volume rendering. The goal is to promote environmental awareness and education around PM2.5 issues.

1. PM2.5 Interpolation and Visualization
based on Wind Fields
ked
2016/05/15
2016/06/13 update

2. Our system
 PM2.5
 http://www.cmlab.csie.ntu.edu.tw/~ked/pm25.htm
 PM2.5 + radar
 http://www.cmlab.csie.ntu.edu.tw/~ked/pm25_4.ht
m

3. Why a different PM2.5 vis. system
2016/04/12

4. The visualization of
 PSI result
2016/04/12

5. The visualization of
2016/04/20

6. The visualization of
 PSI result
 Averaged index
2016/04/12

7. The visualization of
 PSI result
 Averaged index
 Sparse distribution
2016/04/12

8. Other systems for PM2.5
http://env.g0v.tw/air/
2016/04/15

9. Other systems for PM2.5
http://env.g0v.tw/air/ http://env.childgrowth.info/air/
2016/04/15

10. Other systems for PM2.5
http://env.childgrowth.info/air/
天下雜誌 2015.03.17

11. How to interpolate the sparse data

12. Wind & PM2.5
天下雜誌 2015.03.17

13. Wind & PM2.5
東森新聞 2016.01.01

14. Our system
2016/04/15

15. Our system
2016/04/22

16. Outline
 System description
 Data capture
 Interpolation
 Rendering
 Conclusions

17. Outline
 System description
 Data capture
 Interpolation
 Rendering
 Conclusions

18. Features
Interpolation based on winds
x 3D interaction
x Auto-renewal

19. Architecture
Our server
環保署
NCEP
Capture PM 2.5
Interpolate
Capture wind field & height field

20. Architecture
Web browserOur server
環保署
NCEP
Capture PM 2.5
Interpolate
Get data
Visualize &
update
Capture wind field & height field

21. Outline
 System description
 Data capture
 Interpolation
 Rendering
 Conclusions

22. PM2.5 data
Location ?

23. PM2.5 data + coordinate

24. Data of NCEP

25. .grib2 format – records

26. How to read .grib2 file
 Refer to https://www.google.com.tw/url?
sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjCvc7I2Y3MAhVKGJQKHVC4AxgQFgglMAA&url=http%3A%2F%2Fjou-p3.as.ntu.edu.tw
%2FP3%2Ffile%2Fteaching%2Ff1386923093.pdf&usg=AFQjCNF0Z5dLY08WxC5pl_0BUxfTvxUvuQ&sig2=eLDe7X0wv0Ol1KG_Dnr9YQ

27. .grib2 format – regular data
 https://www.google.com.tw/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjCvc7I2Y3MAhVKGJQKHVC4AxgQFgglMAA&url=http%3A
%2F%2Fjou-p3.as.ntu.edu.tw%2FP3%2Ffile%2Fteaching%2Ff1386923093.pdf&usg=AFQjCNF0Z5dLY08WxC5pl_0BUxfTvxUvuQ&sig2=eLDe7X0wv0Ol1KG_Dnr9YQ

28. Outline
 System description
 Data capture
 Interpolation
 Rendering
 Conclusions

29. Vector field

30. Streamline

31. Streamlines

32. Flow in the field

33. Flow in the field

34. Transition
1/3
5/9
1/9

35. Transition – intensity decay
1/3 x 1/2
5/9 x 1/2
1/9 x 1/2
1/2

36. Transition matrix
 Refers to the stochastic process in which the
transition probabilities depend only on the
current state
1/3 x 1/2
5/9 x 1/2
1/9 x 1/2
1/2

37.  Irreducible, aperiodic, recurrent
Stationary Markov chain

38. Stationary Markov chain

39. Outline
 System description
 Data capture
 Interpolation
 Rendering
 Conclusions

40. Implementation
 Javascript + webgl

41. Rendering
Taiwan
PM2.5
Wind vector

42. Scientific visualization
 "it’s infovis when the spatial representation is chosen,
and it’s scivis when the spatial representation is given“
-- wikipedia

43. Volume rendering

44. Volume rendering

45. Billboard
http://www.markmark.net/clouds/

46. Outline
 System description
 Data capture
 Interpolation
 Rendering
 Conclusions

47. Case – 2016.03.14
 " 在臺灣西南側一條繩索狀的
白雲，那是南海吹過來微弱西
南風和東側高壓迴流的交界面
，因為大氣穩定，所以只在海
面上形成一長條的索狀雲。 "

48. Case – 2016.04.08

49. Thx.
站在推廣環保和教育的立場，
我從電腦圖學的角度出發，做了一個互動系統，
希望民眾可以重視 PM2.5 的問題，
更希望的是，
我們的下一代，可以因為我們的覺醒，
而呼吸到更好的空氣。

50. Update
 Streamlines for wind field
 Weather radar for rainfall
 Anaglyph 3D

51. Streamline placement
 Refer to

52. Weather radar data
 Download from

53. Thx.