Recently, pixel numbers and functions of digital cameras are amazingly increasing by modern semiconductor and digital technology, and there are many low-priced digital cameras which have more than 10 mega pixels on the market in Japan. In these circumstances, digital photogrammetry using digital cameras are enormously expected in various application fields. There is a large body of literature on the calibration of digital cameras and circle target detection, location. Target detection and location with subpixel accuracy had been investigated as a star tracker issue, and many centering algorithms have been carried out. It is widely accepted that the least squares modeling of ellipse fitting is the most accurate algorithm. However, there are still problems for efficient close range photogrammetry. These problems are reconfirmation for the target detection and location with subpixel accuracy based on real data which were taken indoors and an indicator for estimating the accuracy of normal close range photogrammetry using digital cameras. With this motive, the empirical testing of several algorithms for target detection and location with subpixel accuracy and an indicator for estimating the accuracy are investigated in this paper using real data which were taken indoors acquired 7 digital cameras which have 7.2 mega pixels to 14.7 mega pixels.
The purpose of this research is to estimate the individual stem volumes with small-footprint LiDAR (Light Detection And Ranging) data. The study area was a plantation of Sugi (Cryptomeria japonica D. Don) and Hinoki (Chamaecyparis obtusa Endl.) with plots of differing densities. We established the regression model to estimate individual stem volumes. Especially, we analyzed the effect of stand density to estimate stem volumes. As a result, the effect by stand density was not admitted both of Sugi and Hinoki. Therefore, we established the regression model to estimate individual stem volumes that does not depend on stand density. Then, we were able to estimate individual stem volumes for Sugi and Hinoki. The cause of the error for stem volumes was presumption accuracy of the tree crown surface area.
Hyperspectral sensor is able to collect information as a set of images in high spectral resolution. It has begun to spread into the field of not only earth resources but also agriculture and environmental surveillance. However, the ground surface resolution of the hyperspectral sensor is not enough in Japan. It is necessary to improve the ground surface resolution so that the hyperspectral sensor comes to wider use. The Wiener filter is able to provide the best restored signal with respect to the square error averaged over the original signal and the noise among linear operators from the observed signal. It is used for many inversion problems. In this paper, we studied the hyperspectrum generation method from the multispectral data based on the Wiener filter. We showed the experimental result that the generated hyperspectrum by using the Wiener filter was corresponding to the original spectrum well.
A new index combined with the normalized difference vegetation index (NDVI) and chlorophyll meter (SPAD) value is proposed and compared with the protein contents of rice grain, as the different time responses of NDVI and SPAD value were observed in the rice paddy measurements. The NDVI is determined from the spectrum measurement using spectrum radiometer. The SPAD value is measured by the chlorophyll meter of the soil and plant analyzer development (SPAD-502, Minolta). Time series of NDVI and SPAD value were measured at the paddy field in Atsushio, Fukushima prefecture, where the rice cv. Koshihikari is cultured with reduced agrichemical and organic fertilizer. The rice protein contents were determined by the taste analyzer, which analyses protein, amylose, and water contents of the rice grain. The variation index between NDVI and chlorophyll content (VNC index) was proposed with the time series measurements of two parameters from the ear emergence period to the duration grain filling. The VNC index and the protein content of rice grain exhibited a positive correlation. This study suggested a possibility to estimate the protein content of rice grain from the VNC index, where NDVI and SPAD value were combined.
The exact location of an excavating machine for allocating small size sewage pipes to be placed under the ground should be measured. A total station used to be applied for the traverse survey in case of larger size of pipes, but it would be difficult for those small size pipes as the total station could not be set in the small pipes. A special digital camera system with two cameras with forward and backward looking has been developed to measure the horizontal and vertical angle between the pipe units which made the traverse survey possible with high accuracy as the length of the pipe unit was precisely measured. However in order to achieve the required accuracy the camera calibration should be performed to assure the angle measurement accuracy. The paper describes the development of the special digital camera system, camera calibration and accuracy analysis.
Geospatial Information Authority of Japan (GSI) has started to maintain “Digital Japan Basic Map (Map Information),” and began broadcasting through the Internet since February 2011. Digital Japan Basic Map (Map Information) integrates information necessary for land management, such as topography and structure, into fundamental geospatial data such as roads and buildings for use as the nation's new basic land information, as a new fundamental map in digital age. This report shows some introduction to Digital Japan Basic Map (Map Information).
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