Tetsuji Ota

Learn More
In this study, we test and demonstrate the utility of disturbance and recovery information derived from annual Landsat time series to predict current forest vertical structure (as compared to the more common approaches, that consider a sample of airborne Lidar and single-date Landsat derived variables). Mean Canopy Height (MCH) was estimated separately(More)
We developed an empirical model to estimate aboveground carbon density with variables derived from airborne Light Detection and Ranging (LiDAR) in tropical seasonal forests in Cambodia, and assessed the effects of LiDAR pulse density on the accurate estimation of aboveground carbon density. First, we tested the applicability of variables used for estimating(More)
We investigated the capabilities of a canopy height model (CHM) derived from aerial photographs using the Structure from Motion (SfM) approach to estimate aboveground biomass (AGB) in a tropical forest. Aerial photographs and airborne Light Detection and Ranging (LiDAR) data were simultaneously acquired under leaf-on canopy conditions. A 3D point cloud was(More)
We have made various measurements on four different types of Hybrid PhotoDiodes (HPDs) with and without magnetic fields. We confirmed that all the four HPDs were operational with a magnetic field with a strength of at least 1.5 T if the device axis was adjusted approximately parallel to the magnetic field direction. Origins of the gain variation in magnetic(More)
We demonstrate a very wide tuning range normal dispersion fiber optical parametric oscillator (FOPO) using a femtosecond, fixed wavelength fiber laser as the pump source. A tuning range from 1360nm to 1835nm with pulse energy up to 1.3 nJ was achieved by operating the FOPO in the normal dispersion regime. We believe that the proposed laser design will be(More)
The quality of diameter measurements for natural old-growth forest was evaluated by comparing repeated field measurements in a diameter census and tree-ring chronologies. The diameter census was repeated three times from 1973 at 10- to 19-year intervals in old-growth Cryptomeria japonica forests on Yakushima Island, Japan. The diameter growth in the three(More)
  • 1