Advanced Land Observing Satellite-2 (ALOS-2) can take data of the disaster stricken area widely, repeatedly even at night and under bad weather condition. These characteristics enable us to demonstrate disaster risk reduction and management for disaster using the satellite data in cooperation with national and local governments. This paper summarizes JAXA's activities and recent outcome of this demonstration.
The Sentinel Asia initiated an emergency observation request system in 2007 to provide image data (and analyzed images) acquired through the satellites operated by the participating space agencies on the WEB and via JAXA's Wideband InterNetworking engineering test and Demonstration Satellite (WINDS), also known as Kizuna, in the event of a disaster in the Asia-Pacific region. Participating disaster management/satellite agencies requested implementation of this activities a total of 234 times as end of 2015. Space agencies of the member countries of the Asia-Pacific Region Space Agency Forum (APRSAF) such as the Japan Aerospace Exploration Agency (JAXA) and disaster management organizations in the Asia-Pacific region such as Asian Disaster Reduction Center (ADRC) cooperate in forming a joint project team (JPT) and promoting the Sentinel Asia. This report provides an overview of the activities and results of the Sentinel Asia, which marks the tenth anniversary of its launch this year.
The Earthquake SAR Analysis Working Group is a group of experts which was established under the Coordinating Committee for Earthquake Prediction in order to detect detailed coseismic ground surface deformation through analyses of SAR images of the Advanced Land Observing Satellite-2 (ALOS-2), develop related techniques, solve seismogenic mechanism from the deformation field and seek ways to utilize SAR data for disaster response and mitigation. Once an earthquake occurs and it is expected to cause coseismic deformation, ALOS-2 urgently observes the affected area upon request from the working group and Japan Aerospace Exploration Agency (JAXA) promptly provides the observation data to members of the working group. Geospatial Information Authority of Japan (GSI), the Secretariat of the working group, has analyzed the data and successfully detected detailed ground surface deformation caused by a lot of earthquakes including the 2014 North Nagano Prefecture Earthquake, the 2015 Nepal (Gorkha) Earthquake and the 2016 Kumamoto Earthquake.
Monitoring volcanic activities is important for safety of people. If the volcanic activity has been increased, the installation of additional sensors near the volcano is difficult. So, Coordinating Committee for Prediction of Volcanic Eruption set up “Satellite Analysis Group" for using ALOS and ALOS-2 data which are able to monitor active volcanos safely in day-and-night or any weather. This report introduces ALOS-2 data's analysis results on Hakone, Kuchinoerabujima, and Sakurajima.
In order to reduce significant damage caused by large-scale of land movement, it is important to detect a sign of large-scale of sediment movements from minute-scales of slope movement at an early stage. Interferometric SAR (InSAR) analysis is considered as an effective method for monitoring land movements. Since we think that it is necessary to have a method for estimating the areas of slope movement indicating a possibility of landslide, which could be helpful for initial actions for disaster countermeasure, we approach the InSAR analysis method. In this study, we compared InSAR analysis data with the data of slope movement collected from a field survey and evaluated it with accuracy rate for estimating several patterns from movements of areas with micro-topography. From this study, we know that InSAR analysis would be effective way to estimate a slope movement of broad areas having micro-topography, showing a high frequency of InSAR fringes.
Currently, many land observation satellites can be used in order to monitor natural environment. For satellite data analysis, reference data is a very important. For instance, DSM (Digital Surface Model) is one of the important data, that can make correct shading and shadow effects in the satellite imagery. Therefore, suitable ground sampling distance of DSM should be understand. In this study, high resolution DSM by aerial LiDAR was used, that ground sampling distance showed 0.2m. A simple satellite image simulation was carried out by computing shading and shadow with the DSM and other field data including spectral reflectance of trees. The simulated satellite image was compared with real satellite image. The target satellite image was ALOS AVNIR-2. The ground sampling distance of ALOS AVNIR-2 is 10m. The standard deviation of the simulation showed less than 3.0 (W/m2/sr/micro m) in infra-red band. The ground sampling distance of DSM was changed from 0.2m to 2.0m. Then, the standard deviation of the simulation showed over 15.0 (W/m2/sr/micro m). A permissive value of the accuracy in infra-red band was 5.1 (W/m2/sr/micro m). The value was computed from standard deviation of real satellite data in simple land cover area. Then, 0.2m ground sampling distance showed same standard deviation with real satellite data.
The Asia Rice Crop Estimation and Monitoring (Asia-RiCE) initiative was launched by Asian space and agricultural agencies in 2012. The initiative promotes strengthening rice monitoring abilities through the use of remote sensing tools, and disseminating relevant, timely and accurate estimation of rice production. In this study, we develop a web-based system (JAXA's Satellite-based Monitoring Network system : JASMIN) to monitor the agrometeorological conditions of paddy areas in Southeastern Asia. JASMIN collects various satellite-derived agrometeorological data, provided by individual servers or websites, and then reprocesses the data spatially and temporally so that it can be used in the initiative. This system provides current and anomalous condition maps, as well as time-series chart in agrometeorological data such as soil moisture, solar radiation, Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), precipitation, and drought index, via the JASMIN website. This satellite-derived information, updated twice a month, is currently used to produce rice growth outlook for Indonesia, Thailand, Philippines, and Vietnam, as part of the Asia-RiCE initiative.
Geospatial Information Authority of Japan (GSI) has produced and published operating manual and safety guidance for UAV survey on the public survey in March, 2016. Procedures and methods for UAV survey are established in the operating manual, and rules for ensuring safety are shown in the safety guidance. We hope that UAV survey becomes widespread by using these manual and guidance especially in the field of public construction works.