ecological viewpoint that allows understanding of an ecosystem based on its
topographic conditions is now recognized. Since Japan is a contracting state of
the Convention on Biological Diversity, the acquisition of information on its
biodiversity based on landscape ecology is essential.
Landscape ecology is the science of studying and improving relationships between
ecological processes in the environment and particular ecosystems. This is done
within a variety of landscape scales, development spatial patterns, and organizational
levels of research and policy (Wu 2006). Landscape ecological map is the thematic
map which shows the distribution of eco-topes, which are the smallest ecologically
distinct landscape features with uniform landform, soil and vegetation. These maps
are usually consisting of the combination of landform classification and vegetation
classification with middle scale such as 1/25,000 or 1/50,000. Recently, by the
development of airborne laser survey technology (Light Detection and Ranging;
LIDAR), it is possible to detect micro landform under the forest (Sato et al. 2007)
and three dimensional forest structure (Nelson et al. 1984; Næsset 1997a, b).
This study aims at understanding the detailed topographic information and the
three dimensional structure of vegetation using airborne laser survey data (airborne
LIDAR data), and developing a technology to construct a dataset to be used for
biodiversity assessment in Japan, based on the above understanding. In this paper,
the author introduces two types of landscape ecological study and mapping using
airborne LIDAR data in natural heritage area and rural area (Koarai et al. 2010a, b,
2011, 2012).
7.2 Airborne Laser Survey Data
Airborne laser survey is an active measurement method in which the distance from
the sensor to the ground is measured by processing the laser beam emitted from the
onboard scanner and reflected on the ground. Aircraft positions are calculated using
combinations of GPS data, both on the aircraft and on the ground. Aircraft acceleration and three-axial attitude data measured by an IMU (Inertial Measurement
Unit) are also used for the calculation. Furthermore, the direction data of the laser
beams are measured by an onboard sensor. These data are combined to calculate the
three dimensional position (X, Y, Z) on the ground (Fig. 7.1).
Akutsu et al. (2005) shows vertical accuracy of airborne laser survey. The sites
which were selected as points for accuracy verification were flat ground surfaces
such as parks. Coordinates of verification points acquired by airborne laser survey
were compared with those derived from the ground survey using GPS and leveling.
The results of comparison with the altitude value of leveling, was 0.03 m on average
(maximum +0.42 m minimum À0.32 m) and the standard deviation was 0.16 m.
One of characteristics of airborne laser survey is the possibility to detect micro
landform under forest. Because of the stereo matching method using aerial photos
will match on a tree crown, DSM will be made from aerial photo. Since a laser pulse
passes through between leaves and reflects a ground surface, it is possible to detect
micro landform under the forest using airborne LIDAR data. Many researches of
138
M. Koarai
topographic conditions is now recognized. Since Japan is a contracting state of
the Convention on Biological Diversity, the acquisition of information on its
biodiversity based on landscape ecology is essential.
Landscape ecology is the science of studying and improving relationships between
ecological processes in the environment and particular ecosystems. This is done
within a variety of landscape scales, development spatial patterns, and organizational
levels of research and policy (Wu 2006). Landscape ecological map is the thematic
map which shows the distribution of eco-topes, which are the smallest ecologically
distinct landscape features with uniform landform, soil and vegetation. These maps
are usually consisting of the combination of landform classification and vegetation
classification with middle scale such as 1/25,000 or 1/50,000. Recently, by the
development of airborne laser survey technology (Light Detection and Ranging;
LIDAR), it is possible to detect micro landform under the forest (Sato et al. 2007)
and three dimensional forest structure (Nelson et al. 1984; Næsset 1997a, b).
This study aims at understanding the detailed topographic information and the
three dimensional structure of vegetation using airborne laser survey data (airborne
LIDAR data), and developing a technology to construct a dataset to be used for
biodiversity assessment in Japan, based on the above understanding. In this paper,
the author introduces two types of landscape ecological study and mapping using
airborne LIDAR data in natural heritage area and rural area (Koarai et al. 2010a, b,
2011, 2012).
7.2 Airborne Laser Survey Data
Airborne laser survey is an active measurement method in which the distance from
the sensor to the ground is measured by processing the laser beam emitted from the
onboard scanner and reflected on the ground. Aircraft positions are calculated using
combinations of GPS data, both on the aircraft and on the ground. Aircraft acceleration and three-axial attitude data measured by an IMU (Inertial Measurement
Unit) are also used for the calculation. Furthermore, the direction data of the laser
beams are measured by an onboard sensor. These data are combined to calculate the
three dimensional position (X, Y, Z) on the ground (Fig. 7.1).
Akutsu et al. (2005) shows vertical accuracy of airborne laser survey. The sites
which were selected as points for accuracy verification were flat ground surfaces
such as parks. Coordinates of verification points acquired by airborne laser survey
were compared with those derived from the ground survey using GPS and leveling.
The results of comparison with the altitude value of leveling, was 0.03 m on average
(maximum +0.42 m minimum À0.32 m) and the standard deviation was 0.16 m.
One of characteristics of airborne laser survey is the possibility to detect micro
landform under forest. Because of the stereo matching method using aerial photos
will match on a tree crown, DSM will be made from aerial photo. Since a laser pulse
passes through between leaves and reflects a ground surface, it is possible to detect
micro landform under the forest using airborne LIDAR data. Many researches of
138
M. Koarai