A STUDY FOR THE METHODOLOGY TO MONITOR MT. SHINMOE-DAKE VOLCANO BY COMBINING ALOS-2, RADARSAT-2, AND TERRASAR-X SATELLITES' DATA

摘要

The Mt. Shinmoe-dake is one of the active volcanoes located in the Kagoshima Prefecture of Japan. Huge eruptions occurred in the recent months and sent tons of ash into the atmosphere. PASCO is performing the spaceborne monitoring of the volcanic activities of Mt. Shinmoe-dake. We have described in the current paper about the evaluation conducted for the coherency and displacement extraction accuracy for the Mt. Shinmoe-dake among ALOS-2, RADARSAT-2, and TerraSAR-X satellites for the development of a combined monitoring methodology. We utilized the satellites' data for the evaluation of same acquisition period and two orbital directions (ascending and descending). Firstly, we evaluated the coherency between ALOS-2 and ALOS. The results showed that coherence value of ALOS-2 was higher comparing to ALOS. Even though RADARSAT-2 and TerraSAR-X had shorter acquisition date intervals comparing to ALOS-2, the obtained coherence was only limited to a portion of the scene. Our study indicated that regarding the coherence, ALOS-2 showed better coherence results. For the extraction accuracy, TerraSAR-X resulted higher accuracy. However, we observed that there were insignificant differences of the accuracies among the three satellites for Mt. Shinmoe-dake and the vicinity. The study confirmed about the possibility of a combined monitoring methodology.