Adam Dick M.Sc.F. Candidate, University of New Brunswick 2007 Western Mensurationists Meeting

1. Adam Dick M.Sc.F. Candidate, University of New Brunswick 2007 Western Mensurationists Meeting June 24-26, 2007 Kelowna, B.C.

2. Introduction A Google example: 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 2

3. Introduction 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 3

4. Introduction 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 4

5. Introduction 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 5

6. Introduction 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 6

7. Introduction 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 7

8. Introduction Photography has been an important tool used by foresters for many years Satellite/ aerial photography underpins most large scale inventories What if we could have an in-stand perspective to help interpret collected data? Assist by making data collection more efficient? 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 8

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10. 360- degree photography • Equipment • Digital camera • Tripod • Tripod mount • Ensures nodal point of lens is above rotational axis of tripod • Eliminates parallax errors 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 10

11. 360- degree photography Camera mounted vertically Photo every 15-degrees 24 photos per plot Ensures adequate overlap between adjacent images Focus, flash settings the same around plot 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 11

12. 360- degree photography 5 January 2020 • Software (Panorama Factory v4.5) • Automates stitching process • Automatically corrects barrel distortion, detects focal length Adam Dick ~ Western Mensurationists Meeting 12

13. 360- degree photography 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 13

14. 360- degree photography Unwrap and print out flat stand Distortion free Consistent scale 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 14

15. So……… How can we use these photographs? 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 15

16. Using photography 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 16

17. Spatial tree mapping • To calculate distance to object • Dimension of the tree (or surrogate) • And camera focal length 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 17

18. Spatial tree mapping Calculate azimuth to object 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 18

19. Spatial tree mapping Azimuth of first tree measured used as reference Could arbitrarily start at zero if only relative position of trees is required 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 19

20. Using photography 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 20

21. Angle count sampling (ACS) • Bitterlich 1948 • “basal area density of a unit area of area can be estimated by counting those trees whose diameter at breast height (dbh) subtended angles appearing larger than the horizontal angle-gauge” (Grosenbaugh 1958) 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 21

22. Angle count sampling (ACS) • Using a camera • Decourt, N. 1956 Utilisation de la photographie pour mesurer les surfaces terriers. Revue forestière française, Vol 8. No.7 pp.505-507 • Adaptation of Bitterlich to use photographs 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 22

23. Angle count sampling (ACS) • Several methods identified to do ACS • Measure width of trees in photograph • Calculate the BAF of each tree • Apply desired BAF constant (e.g. mBAF2) 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 23

24. Angle count sampling (ACS) Calibrate gauge width for photograph Count trees larger than gauge width 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 24

25. Angle count sampling (ACS) Do as a prism does Shift the tree at breast height by gauge width Tree overlaps: in Tree cut: out 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 25

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27. 49 plots • Sampled trees with a mBAF1 prism • 1400 trees sampled • Measured tree DBH • Distance and azimuth to each tree • Took photographs at each plot 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 27

28. 5 January 2020 • Sampled across range of densities • Stand types • 2 camera models • Olympus D550Z, 3 megapixels • Canon PowerShot SD200, 3.2 megapixels Adam Dick ~ Western Mensurationists Meeting 28

29. Spatial tree mapping • Azimuth calculations • Linear regression • Field measurements vs. measurements from photo 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 29

30. Spatial tree mapping 5 January 2020 • Distance calculations • Linear regression • Field measurements vs. measurements from photo Adam Dick ~ Western Mensurationists Meeting 30

31. Spatial tree mapping Photography is underestimating the distance Azimuth is generally good Relative positions of the trees is good Need to adjust the focal length 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 31

32. Angle count sampling (ACS) Tree visibility by BAF Selection Tree Visibility by distance 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 32

33. Angle count sampling (ACS) 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 33

34. BAF calculations • Field measurements vs. measurements from photo 5 January 2020 Adam Dick ~ Western Mensurationists Meeting 34

35. Plot 52 – Pre Harvest Plot 52 – Post Harvest Other Applications As a monitoring tool Repeated measures 5 January 2020 Maintain data integrity Prescription training tool Adam Dick ~ Western Mensurationists Meeting 35