The InflateSAR Campaign: Developing Refugee Vessel Detection Capabilities with Polarimetric SAR

Citation

Lanz P, Marino A, Simpson MD, Brinkhoff T, Köster F & Möller M (2023) The InflateSAR Campaign: Developing Refugee Vessel Detection Capabilities with Polarimetric SAR. Remote Sensing, 15 (8). https://doi.org/10.3390/rs15082008

Abstract
In the efforts to mitigate the ongoing humanitarian crisis at the European sea borders, this work builds detection capabilities to help find refugee boats in distress. For this paper, we collected dual-pol and quad-pol synthetic aperture radar (SAR) data over a 12 m rubber inflatable in a test-bed lake near Berlin, Germany. To consider a real scenario, we prepared the vessel so that its backscattering emulated that of a vessel fully occupied with people. Further, we collected SAR imagery over the ocean with different sea states, categorized by incidence angle and by polarization. These were used to emulate the conditions for a vessel located in ocean waters. This setup enabled us to test nine well-known vessel-detection systems (VDS), to explore the capabilities of new detection algorithms and to benchmark different combinations of detectors (detector fusion) with respect to different sensor and scene parameters (e.g., the polarization, wind speed, wind direction and boat orientation). This analysis culminated in designing a system that is specifically tailored to accommodate different situations and sea states.

Keywords
polarimetry (PolSAR); constant false alarm rate (CFAR) detector; polarimetric detector; sub-look detector; vessel-detection system (VDS); ship detection; synthetic aperture radar (SAR); disaster mitigation, refugee boat

Journal
Remote Sensing: Volume 15, Issue 8