HR: 1340h
AN: B43B-0286    [Abstracts]
TI: Development of the Method to Estimate Plant Area Density by Helicopter Mounted Side-looking LIDAR
AU: * Takeda, T
EM: takeda.tomomi@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506 Japan
AU: Oguma, H
EM: oguma@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506 Japan
AU: Yone, Y
EM: yone.yasumichi@nies.go.jp
AF: PASCO Corporation, 1-1-2 Higashiyama, Meguro-ku, Tokyo, 153-0043 Japan
AU: Fujinuma, Y
EM: fujinuma@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506 Japan
AB: In order to measure PAI (Plant Area Index) and APIA (Average Plant Inclination Angle) of a forest, the inversion method based on gap fraction which is the penetration of sun beam through the canopy is widely used. We used ground based laser scanner, and succeeded in measuring PAD (Plant Area Density) and APIA in horizontal layer from a penetration of laser beam through the canopy instead of sun beam. However, the measurement using a laser scanner had the problem that a lot of time and labor were required and the measurement area was restricted to small. So, this study examined how to measure gap fraction of a forest in a wide area using helicopter mounted side-looking LIDAR in order to measure PAD and APIA of a forest in a wide area. The wavelength, the divergence angle and the range of scannig angle of laser beams were 1.06 μm, 0.5 mrad and 60°, respectively. By attaching this laser scanner to helicopter with leaning 30°, it was able to become shoot a laser beam in the wide range from directly below to 60°, and the shooting angle of the laser beams which were needed by measurement of gap fraction was able to be obtained in the large range. The measurement was conducted on September 8, 2003 for 45-year-old Japaneser larch ( Larix kaempferi Sarg.) in the national forest in Tomakomai, Hokkaido, Japan (42°44'N, 141°31'E). The area of 500 m × 2100 m scanned by helicopter was divided into 105 plots of 100 m × 100 m, and PAD and APIA were measured in the horizontal layer with a thickness of 1 m in all plots. Simultaneously, a measurement of PAD and APIA was conducted using ground based laser scanner at 2 plots of forest floor. As a result of comparing two methods, the relation of 1:1 was seen for PAI and APIA that were integrated within the plot. On the other hand, comparing the profile of PAD, the height of a peak of PAD measured by the helicopter mounted side-looking LIDAR was lower than ground based laser scanner. Moreover, correlation was hardly found among both of the methods about PAD and APIA. As this reason, since there was an difference of altitude within the plot of 100m × 100m, when PAD and APIA were averaged within a plot, it was considered that vertical distribution cannot be measured correctly.
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0452 Instruments and techniques
DE: 0480 Remote sensing
SC: Biogeosciences [B]
MN: Fall Meeting 2005