Clayton M. Bjorland;Zorana Jelenak;Joseph W. Sapp;Casey G. Shoup;Bradley M. Isom;Paul S. Chang;James R. Carswell
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引用次数: 0
Abstract
KaIA is an airborne Ka-band radar altimeter capable of centimetric range resolution and near real-time significant wave height retrievals. Beginning in 2019, KaIA has been installed on National Oceanic and Atmospheric Administration (NOAA) WP-3D Hurricane Hunter aircraft to collect data in Atlantic tropical cyclones during the hurricane season, and extratropical cyclones during the winter storm season. This article details recent retracker algorithm innovations that address specific difficulties with airborne altimetry in extreme weather. Our two most significant contributions to retracker algorithm development are: 1) a higher-order expansion of the classic Brown (1977) altimetry waveform to accommodate off-nadir pointing angles up to 3.25${}^{\circ }$; 2) a GPS stabilization algorithm to enable along-track averaging while aircraft altitude is changing unpredictably. Comparisons against coincident measurements and modeled data are presented to validate algorithm improvements and document KaIA's performance throughout the 2021-2023 hurricane seasons. We measure less than 0.1 m bias in significant wave height retrievals relative to coincident satellite altimeters.
期刊介绍:
The IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing addresses the growing field of applications in Earth observations and remote sensing, and also provides a venue for the rapidly expanding special issues that are being sponsored by the IEEE Geosciences and Remote Sensing Society. The journal draws upon the experience of the highly successful “IEEE Transactions on Geoscience and Remote Sensing” and provide a complementary medium for the wide range of topics in applied earth observations. The ‘Applications’ areas encompasses the societal benefit areas of the Global Earth Observations Systems of Systems (GEOSS) program. Through deliberations over two years, ministers from 50 countries agreed to identify nine areas where Earth observation could positively impact the quality of life and health of their respective countries. Some of these are areas not traditionally addressed in the IEEE context. These include biodiversity, health and climate. Yet it is the skill sets of IEEE members, in areas such as observations, communications, computers, signal processing, standards and ocean engineering, that form the technical underpinnings of GEOSS. Thus, the Journal attracts a broad range of interests that serves both present members in new ways and expands the IEEE visibility into new areas.