Applications and prospects of terrestrial LiDAR and drones for an improved forest inventory

Transcription

1 Applications and prospects of terrestrial LiDAR and drones for an improved forest inventory A review based on current literature Erich Seifert Stefan Seifert Anton Kunneke David M Drew Jan van Aardt Thomas Seifert

2 Bibliometrics Publications over time Number of papers Year Drones Terrestrial LiDAR Data source: Scopus search for ( "terrestrial laser scanning" OR "terrestrial LiDAR" OR "t-lidar" ) AND ( "forest" OR "forestry" ) ( "UAV" OR "drone" OR "umanned aerial") AND ( ( forest OR tree ) AND measurement OR forestry ) Precision Forestry Symposium 2017 Stellenbosch 28th February

3 Bibliometrics Publications per country Terrestrial LiDAR Drones United States China Germany Finland Canada Australia United Kingdom France Netherlands Austria United States China Spain Australia Germany Canada Brazil Finland France South Korea Number of publmcatmons Number of publmcatmons Data source: Scopus Precision Forestry Symposium 2017 Stellenbosch 28th February

4 Terrestrial LiDAR Technology Time-of-flight (pulse-based) Phase-shift Source: Stefan Seifert Precision Forestry Symposium 2017 Stellenbosch 28th February Source: Zoller+Fröhlich GmbH 4

5 Terrestrial LiDAR Technology Source: Dassot et al Precision Forestry Symposium 2017 Stellenbosch 28th February 5

6 Terrestrial LiDAR Technology Source: Anton Kunneke Precision Forestry Symposium 2017 Stellenbosch 28th February 6

7 Terrestrial LiDAR Development of hardware Prmce [1,000 ] Accuracy at 50m [mm] Year Year Precision Forestry Symposium 2017 Stellenbosch 28th February 7

8 Terrestrial LiDAR Development of hardware Speed [1,000 pomnts/s] Wemght [kg] Year Year Precision Forestry Symposium 2017 Stellenbosch 28th February 8

9 Drones Technology Fixed-wing Multicopter Source: sensefly SA Source: DJI Source: QuestUAV Source: multikopter.cc Precision Forestry Symposium 2017 Stellenbosch 28th February 9

10 Drones Technology Take-off and landing area Cruise speed Maximum flight time Maximum coverage (single flight) Fixed-wing Large e.g. 20 m 15 m High km/h High minutes High ~ 12 km² Multicopter Very small vertical take-off/ landing Low Medium km/h Low minutes Low ~ 0.3 km² Precision Forestry Symposium 2017 Stellenbosch 28th February 10

11 Drones Flight planning Source: SPH Engineering Precision Forestry Symposium 2017 Stellenbosch 28th February 11

12 Drones Multiple View Geometry Precision Forestry Symposium 2017 Stellenbosch 28th February 12

13 Drones Multiple View Geometry Precision Forestry Symposium 2017 Stellenbosch 28th February 13

14 Forest inventory Traditional inventory Measured values DBH Height Number of trees Species Position Secondary target variables Taper and volume Biomass Log assortments f (DBH, h) Precision Forestry Symposium 2017 Stellenbosch 28th February 14

15 Forest inventory Additional information from Terrestrial LiDAR Source: Dassot et al Precision Forestry Symposium 2017 Stellenbosch 28th February 15

16 Forest inventory Additional information from Terrestrial LiDAR Bark texture analysis Tree species recognition Detection of external wood defects Source: Dassot et al Precision Forestry Symposium 2017 Stellenbosch 28th February 16

17 Forest inventory Additional information from Terrestrial LiDAR Bark texture analysis hornoeam oan spruce oeech pine Source: Othmani et al Precision Forestry Symposium 2017 Stellenbosch 28th February 17

18 Forest inventory Additional information from Terrestrial LiDAR Bark texture analysis Tree species recognition Detection of external wood defects Geometrical fitting Diameters (DBH, stem and branch profiling) Wood volumes / Stand value Stem density / Basal area Tree height Source: Dassot et al Precision Forestry Symposium 2017 Stellenbosch 28th February 18

19 Forest inventory Additional information from Terrestrial LiDAR Geometrical fitting Source: Hackenberg et al Source: Raumonen et al Precision Forestry Symposium 2017 Stellenbosch 28th February 19

20 Forest inventory Additional information from Terrestrial LiDAR Bark texture analysis Tree species recognition Detection of external wood defects Geometrical fitting Diameters (DBH, stem and branch profiling) Wood volumes / Stand value Stem density / Basal area Tree height Plot cartography Digital Terrain Model Stem detection and location Source: Dassot et al Precision Forestry Symposium 2017 Stellenbosch 28th February 20

21 Forestry Usage of drones Individual trees / stems Multicopter, 45 angle, MVG reconstruction, Comparison with TLS Source: Fritz et al Precision Forestry Symposium 2017 Stellenbosch 28th February 21

22 Forestry Usage of drones Tree height Fixed-wing drone Reconstruction with MVG Comparison with TLS data Source: Lisein et al Precision Forestry Symposium 2017 Stellenbosch 28th February 22

23 Forestry Usage of drones Spatial gaps in forests Fixed-wing drone 10 ha area Source: Getzin et al Precision Forestry Symposium 2017 Stellenbosch 28th February 23

24 Drone point clouds Airborne LiDAR vs. Digital Aerial Photogrammetry Airborne LiDAR Photogrammetric reconstruction Source: Wallace et al Precision Forestry Symposium 2017 Stellenbosch 28th February 24

25 Conclusion Terrestrial LiDAR can provide detailed below-canopy information, but it requires intensive field work, so it cannot be applied to large areas Drones can provide improved above-canopy and forest structure information at a fraction of the cost of terrestrial LiDAR. However, it does not reach the same level of accuracy and detail. Both technologies have considerably matured in the past decade and have reached a technological level that warrants their use for forest inventory Precision Forestry Symposium 2017 Stellenbosch 28th February 25

26 Outlook Drones fly in the forest SLAM: Simultaneous Localization and Mapping Swarm intelligence Machine learning Source: Astec Precision Forestry Symposium 2017 Stellenbosch 28th February 26

27 Acknowledgements Co-authors Stefan Seifert Anton Kunneke David M. Drew Jan van Aardt Thomas Seifert Scientes Mondium Stellenbosch University Stellenbosch University RIT Scientes Mondium, Funding Stellenbosch University Precision Forestry Symposium 2017 Stellenbosch 28th February 27