Airborne LiDAR for forest mapping
Poate Degei1, Fabian Enßle², Wolf Forstreuter1 Barbara Koch²
1
SPC/SOPAC GIS/RS
²Department of Remote Sensing and Landscape Information Systems - FeLIS
fabian.enssle@felis.uni-freiburg.de
Outline
09.04.2015
•
Introduction to Airborne Laser Scanning (ALS)
•
ALS data recorded at Nadi
•
Various capabilities of LiDAR data
•
TreesVIS software
•
Summary & Conclusion
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
2
Airborne Laserscanning (ALS)
09.04.2015
• ALS is an active remote sensing technique
• Laser scanner can be mounted on airplanes,
helicopters or UAV’s
• Laser scanner technology has several advantages
• 3D mapping of vegetation
• Laser penetrates thru canopy
•
Principals and data will be described in next slides
Source: http://www.riegl.com
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
3
Airborne Laserscanning (ALS)
C. Brenner ISPRS Summer school 2006
Easting
Northing
3462486.09
5483534.20
3462484.77
5483533.61
3462483.42
5483533.01
3462482.08
5483532.41
3462480.75
5483531.82
3462479.44
5483531.23
3462478.12
5483530.64
3462477.01
5483530.14
3462475.51
5483529.47
3462474.22
5483528.89
3462472.91
5483528.30
3462471.57
5483527.71
3462470.43
5483527.19
LILLESAND ET AL. 2008
3462468.92
5483526.52
Elevation
93.74
93.97
93.50
93.50
93.48
93.87
94.02
97.74
94.89
95.49
95.78
95.77
98.49
95.90
Intensity
32
35
74
25
55
94
107
28
58
78
32
25
18
41
TSOULIS 2006
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
4
Airborne Laserscanning (ALS)
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
5
ALS data flight in Nadi area
09.04.2015
First ALS data recorded in Viti Levu
•
Financed by World Bank
• May, 2012
• Island Hoppers helicopter
• Light Detection & Ranging
equipment
Demonstration area
• A subset is used in next slides
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
6
Airborne Laserscanning (ALS)
Bird view
A
B
Look from Mark B towards A
Cross section between mark A and mark B (depth 5m)
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
7
Airborne Laserscanning (ALS)
Calculation of Digital Terrain Models (DTM)
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
8
Airborne Laserscanning (ALS)
Calculation of Digital Surface Models (DSM)
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
9
Airborne Laserscanning (ALS)
normalized DSM (nDSM)
• Height of objects
• Vegetation
• Buildings
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
10
Airborne Laserscanning (ALS)
Inclination (surface slope) calculation
• Precise DTM‘s important
• Accessibility to forests
• Environmental modeling
• Soil erosion
• Water drainage
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
11
Airborne Laserscanning (ALS)
Assessment of multilayer structure within the vegetation
Wang et al. 2007 FeLis
09.11.2010
Double layer
forest stand
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
Single layer
forest stand
with trees of
mixed height
12
Airborne Laserscanning (ALS)
Assessment of canopy closure and height
• Forest segmentation
• By height
• Canopy closure
• Species composition
Example from a German forest (by Christoph Straub)
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
13
TreesVIS – Software skills
• Data processed with TreesVIS
3D real-time visualisation
• Developed at Dep. of Remote
Sensing; University Freiburg
• Special prices for research and
Processing and filtering of raw data
Calculation of DSM, DTM, nDSM
students
True orthophoto calculation
Combining TLS and ALS data
Modules for object extraction
Laser flight simulation
09.11.2010
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
14
Summary & Conclusion
Various capabilities of LiDAR technology
•
3D point information
• Precise Digital Surface Models
• Precise Digital Terrain Models even under forest canopy
• Data is useful for multiple purposes
• Forest mapping
• Environmental and Disaster modeling/mapping
• Urban area mapping (houses, transmission lines)
• Data acquisition is expensive, but of high value due to its use
for multiple purposes
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
15
Thank you for your attention
Vinaka Vakalevu
The authors are greatful to:
The ReCover consortium within the FP7 programme (no. 263075)
http://www.vtt.fi/sites/recover/?lang=en
09.04.2015
27.11.2012 – 30.11.2012 PACIFIC GIS/RS USER CONFERENCE
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