This paper tries to develop a new slope investigation method using remote sensing on the ground. The method consists of "thermal infrared remote sensing" and "visible and near infrared remote sensing". This paper reports some results of fundamental experiments for applying the remote sensing to rock mass slope investigation. In the experiments, we used some kinds of rock samples, changing the color, dry specific gravity and degree of weathering. At first, we observed spectral reflectance and temperature of the surface of rock samples. Secondly, we calculated L*a*b* values from the spectral reflectance and calculated the rate of increment of temperature from the temperature. From the relationship between the observed data and properties of the samples, we recognize that it is possible to estimate the stage of weathering and the dry specific gravity. The results show the possibility of our investigation method by remote sensing on the ground for applying the actual rock slope.
We have developed an air-borne ultraviolet remote sensor, named "Airborne-OPUS." It is a nadir-looking hyper spectral imaging spectrograph, with 1100 spectral channels and 330 spatial channels. It covers the wavelength range of 190-455 nm with 0.34 nm sampling step and covers 15 degrees field of view. All main components of the sensor are composed of commercially available products : a Jobin-Yvon spectrograph as a disperser, a PixelVision 1100×330 CCD camera as a detector, and a ready-made single lens as its front-end optics. For the data calibration, we examined the basic parameters and the performance characteristics of the detector, such as read noise, dark current, linearity, and pixel-response uniformity. After two-demonstration flights using the Gulfstream-II aircraft, the performances of Airborne-OPUS, such as spectral resolution, signal-to-noise ratio, have been evaluated. In the flights around Miyake-jima and Sakura-jima volcanoes, the absorption structure of SO2 was detected in the observed spectra, using the DOAS technique. The vertical column amount of SO2 was derived from each data, and its horizontal distribution was revealed. The sensitivity of the sensor was also examined, and we discussed its application to the detection of urban pollutions.
We proposed a new geometric correction method, where correlation between simulated irradiance image and ortho-rectified satellite image was used to evaluate geometric transform equation and to optimize its parameters. In this paper, we apply the method to 22 system-corrected Landsat TM images from 1984 to 2000 to check their accuracy and chronological change over 8 study areas. It is shown that there is large distortion in some images processed after 2000. NASDA announced that the usage of nominal orbit information instead of actual orbit information caused this distortion. At present, this type of distortion is mitigated and optimization on two parameters (scene center displacement) seems sufficient for relatively narrow area (18 km × 18 km) as we noted before.
It is important to survey topography around debris flow precisely and speedy for disaster prevention. Aerial/ground survey has been used for such a survey. However, these method are neither sufficiently speedy nor safety. Airborne LIDAR is a new technology, which can acquire precise topography data speedy and safety. In this paper, some sample images of debris flow, those are acquired by airborne LIDAR in Kyushu district are introduced.
Digital Asia is an initiative to provide people and communities with easy access to geo-spatial information over the Internet through open sharing of GIS and Remote Sensing Data among all the countries of Asia. Digital Asia will form the Digital Asia Network (DAN) to bring together all participating people and agencies, and to provide a place where they can obtain useful information for developing their applications and demonstration systems. As a three-year activity, DAN would support participants' efforts to link these Web-based GIS systems to demonstrate the usefulness of data availability and data sharing for society. The main objectives of Digital Asia are (1) to develop a mechanism for data sharing, so that partners can participate easily, (2) to provide guidelines for developing applications and demonstration systems, (3) to help any agencies, through sharing of technical knowledge and training, who would like to open their data, (4) to stimulate development of demonstration systems which will be the basis of a future operational system, and (5) to share experience and "lessons learned" through development of demonstration systems. To promote this DAN concept, NASDA agreed to support a DAN preparation meeting in cooperation with the DAN secretariat at the Asian Institute of Technology (AIT), and the preparation of a three-year implementation plan for DAN. This paper describes the overview of Digital Asia Network concept and the implementation plan.