In recent years environmental problems in the coral reefs attract both scientific and social attentions. However, most coral reefs have few maps showing the reef topography and the distributions of various benthic habitats in the reef. Satellite remote sensing can be used for coral reef mapping because satellites can observe the reefs scattered in tropical oceans in a short time repeatedly. Simple comparison between satellite images acquired on two different days is, however, strongly affected by the changes of the tidal level. Applying conventional classification algorithms to such satellite images often results in misclassification. We developed Bottom Index (BI) algorithm to minimize the water depth effect on satellite data. BI is a modified reflectance ratio between two bands in satellite data and corresponds to the proportion of benthic community cover in a pixel. In this study we applied this algorithm to Landsat TM data acquired during 1984-1996 on Ishigaki coral reefs, Japan, and evaluated its accuracy. We also developed the method for the separation of sand and coral / algae / seagrass habitat using BI. We also found that the extinction coefficient ratio between two TM bands that is necessary for BI algorithm was basically constant there. And temporal variations of the sea floor cover type in Ishigaki during 1984-1996 were indicated by BI maps. Sea truth survey was conducted in August 2000 to validate the BI maps.

Since the 1970s, Earth-observing satellites collect increasingly detailed environmental information on land cover, meteorological conditions, environmental variables and air pollutants. This information spans the entire globe and its acquisition plays an important role in epidemiological analysis when in situ data are unavailable or spatially and/or temporally sparse. In this paper, we present the development of Japan Aerospace Exploration Agency’s (JAXA) Public-health Monitoring and Analysis Platform available from JAXA, a user-friendly, web-based system providing environmental data on shortwave radiation, rainfall, soil moisture, the normalized difference vegetation index, aerosol optical thickness, land surface temperature and altitude. This system has been designed so that users should be able to download and utilize data without the need for additional data processing. The website allows interactive exchange and users can request data for a specific geographic location and time using the information gained for epidemiological analysis.

Abstract. The “Advanced Land Observing Satellite-3” (ALOS-3, nicknamed “DAICHI-3”) is the next high-resolution optical mission as a successor of the optical mission by the Advanced Land Observing Satellite (ALOS, “DAICHI”) in Japan Aerospace Exploration Agency (JAXA), and will be launched in Japanese Fiscal Year 2020. ALOS-3 is now under developing the flight model. The major missions of ALOS-3 are (1) to contribute safe and secure social including provision for natural disasters, and (2) to create and update geospatial information in land and coastal areas. To achieve the missions, the “WIde-Swath and High-resolution optical imager” (WISH, as a tentative name) is mounted on ALOS-3, which consists of the high-resolution panchromatic- and multispectral-bands.This paper introduces the overview of ALOS-3’s mission and the calibration and validation plan at JAXA. The standard product is the system corrected data using the sensor models, which will be provided from the sensor development team. Therefore, the sensor calibration is directly affected to the accuracies of the standard product. In addition, the sensor model based the Rational Polynomial Coefficient will be contained with level 1B2 standard product that can be used to process an ortho rectification and three-dimensional measurement from ALOS-3 images. As the target accuracy of WISH’s standard products, the geometric accuracies are less than 5 m in horizontal without ground control point (GCP), and 1.25 m in horizontal and 2.5 m in vertical with GCPs (1 sigma), and the radiometric accuracy is ± 10 % as absolutely and ± 5 % as relatively for multispectral band.

Shonai Plain is famous paddy area in Japan. As a countermeasure overproduction of rice in Japan, there are many other crops not rice in the paddy fields. We try to determination of planted crops using satellite data. Recently, in Asian countries, GIS is spread widely and agricultural field polygon is commonly used. Crop determination using the polygon is becoming popular. Normally, fields are used without changing, but sometimes, one field is divided two or three fields, and two or three fields are integrated one field. It is necessary to overlay satellite image and the polygon, and to check with fitting or not. In case of mismatch, field polygon must be corrected. Simultaneously with this confirmation work for each field polygon, the optical satellite data were classified as water surface ‘water’, vegetation as ‘vegetation’, bare soil as ‘soil’ and ‘cannot determination’. In the SAR image, we classify 4 degrees, as small scattering of the water surface ‘0’, scattering slightly larger than the water surface ‘1’, larger than the water surface ‘2’, and large scattering ‘3’. The crop determination is performed according to the following standard using to the time series data. (a) Rice: Almost water surface at rice planting time and following several weeks. In summer, there is large vegetation. (b) Wheat: There is large vegetation at rice planting time, and small vegetation at summer. (c) Soybean: There is small vegetation at rice planting time, and large vegetation in summer. Using this evaluation criteria, we performed the crop classifications in Shonai Pain by ALOS2 and Sentinel2 data, and the correct answer rates are more than 95% at both satellite data.

Temporal changes in pore structure due to weathering during 350ka were examined using sandstone gravel in fluvial terrace deposits which were distributed in the Miyazaki Plain, south Kyushu.The time between the age of each terrace formation and the present was assumed to be the weathering period. Using rock samples taken from the outcrop in each terrace,(1)microstructure of rock samples were observed through an optical microscope and X-ray CT Scanning analysis,(2)specific gravity and effective porosity of the samples were measured, and(3)pore size distribution(PSD)of rock samples were measured by a mercury intrusion porosimetry. Main results are summarized as follows: (1)the optical microscope observation shows that pores are connected due to weathering,(2)the CT values decrease with increasing weathering period,(3)the specific gravity decreases and the effective porosity increases with increasing weathering period, and(4)the pore radius and the pore volume increases with increasing weathering period, (5)the specific surface area increases with constant rate during 350ka. These results suggest that increasing of pores in gravel with increasing weathering period is derived from leaching of the matrix minerals with a small specific surface area.