Evaluation of the ICEYE constellation for observing short-term surface displacements induced by volcanic activity

Abstract

ICEYE operates the world’s largest SAR constellation, offering global imaging services with more than 60 X-band SAR satellites launched since its first mission in 2018. The continuous expansion of the ICEYE fleet enables short-repeat observations of the Earth, which is crucial for responding to natural disasters such as floods, earthquakes, and volcanic activities. While ICEYE data have demonstrated capabilities in amplitude-based analysis for Earth science applications, the potential for InSAR analysis as part of the international SAR constellation has only begun to be explored. In particular, global monitoring and rapid response capabilities for short-term volcanic activity benefits immensely from a dense, multitemporal satellite network. Here, we quantitatively assessed the InSAR capability and quality of ICEYE data for observing volcanic activity over two locations: Kı̄lauea volcano (Hawai’i, US) and Reykjanes Peninsula (Iceland). We examined important InSAR quality metrics, namely decorrelation characteristics and accuracy of deformation measurement relative to GPS/GNSS, and then analyzed the feasibility of measuring three-dimensional (3D) displacements. We found that ICEYE data quality was more variable and had higher error relative to GPS/GNSS than other X-band satellites we studied, in particular COSMO-SkyMed (CSK), TerraSAR-X (TSX), and TanDEM-X (TDX). Furthermore, as with many current NewSpace providers, data tasking can be challenging. Still, we were able to demonstrate initial 2D deformation retrieval, which can be expanded to 3D retrieval if multiple geometries can be leveraged. These capabilities can be combined with ICEYE’s very short temporal baselines to enable unprecedented rapid-repeat observations of volcanic activity. Despite the reduced InSAR performance of the ICEYE constellation relative to larger InSAR-capable satellites, the fleet contributes unique capabilities to the global SAR constellation for capturing deformation patterns associated with rapidly evolving volcanic events.