Surface displacement due to the 2014 North Nagano, Japan earthquake estimated from differential interferometry technique with ALOS-2 PALSAR-2 data

摘要

There are several new SAR satellites launched in the last years, and it becomes quite important to understand the measurement capability of the new sensors. The Japan Aerospace Exploration Agency (JAXA) launched ALOS-2 PALSAR-2 satellite in 2014, and the measurement of surface deformation with this new sensor is expected to be more accurate than the previous sensors such as JERS-1 and ALOS PALSAR-1. In this paper, we used PALSAR-2 data in order to measure displacement induced by the 2014 North Nagano earthquake (M6.7) occurred on November 22nd in Japan. A standard differential interferometry process (DInSAR) was carried out with PALSAR-2 data, and the results were validated with the permanent GPS data and the field survey data measured by disaster response activities for this earthquake. Although the validation is not quantitative analysis, the direction and amount of the deformation derived from DInSAR correspond to the ground truth data, and we conclude that PALSAR-2 should be essential data source to measure surface deformation with wide area.