Japan Geoscience Union Meeting 2023

Presentation information

[J] Oral

S (Solid Earth Sciences ) » S-TT Technology & Techniques

[S-TT39] Synthetic Aperture Radar and its application

Wed. May 24, 2023 10:45 AM - 12:00 PM 304 (International Conference Hall, Makuhari Messe)

convener:Takahiro Abe(Graduate School of Bioresources, Mie University ), Yohei Kinoshita(University of Tsukuba), Yuji Himematsu(National Research Institute for Earth Science and Disaster Resilience), Haemi Park(Graduate School of Global Environmental Studies, Sophia University), Chairperson:Yohei Kinoshita(University of Tsukuba), Yuji Himematsu(National Research Institute for Earth Science and Disaster Resilience)


11:30 AM - 11:45 AM

[STT39-04] High-resolution imaging of oceanic heavy rain signals by ALOS-2 full-polarimetry

*Masato Furuya1, Ito Ide2 (1.Department of Earth and Planetary Sciences Hokkaido University, 2.Earth and Planetary Sciences, Faculty of Science, Hokkaido University)

Keywords:ALOS-2, SAR, heavy rain, oceanic area, full polarimetry

Advanced Land Observing Satellite-2 (ALOS-2), launched by JAXA in 2014, carries Phased-Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) that delivers high-spatial-resolution radar images to monitor natural disasters such as earthquakes, volcanic eruptions, floods, and so forth. Besides land areas, PALSAR-2 imageries over oceanic regions have been used to estimate surface winds and sea-ice distributions. However, there are few observation reports of heavy rain episodes over oceanic areas by PALSAR-2, while rain signals would become noise for wind velocity retrieval. Alpers et al (2016) reviewed radar imaging of rain footprints over the ocean but focused mostly on C-band radar images. Here we report two heavy rain episodes over the ocean off south Kyushu imaged by ALOS-2/PALSAR-2 full-polarimetric mode, whose maximum spatial resolution is ~6m.
Figure 1 indicates the amplitude image of the HH-channel acquired on August 11, 2021 with a darker (brighter) area indicating weaker (stronger) scattering amplitude. Comparing Figure 1 with the JMA's rain radar map at the epoch, we confirm that the darker (brighter) area corresponds to higher (lower) rain-rate area. By analyzing other channels, HV, VH, and VV, we aim to map the rain intensity distribution with high-spatial-resolution.