Publications
論文誌 (国際) A-UVI: GNSS-Assisted EO-based UV Index Estimation Method for Individual-level Precise UV Exposure Assessment
Yuuki Nishiyama (The University of Tokyo), Subaru Atsumi (The University of Tokyo), Kota Tsubouchi, Kaoru Sezaki (The University of Tokyo)
The Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT)
2025.6.25
Excessive or insufficient exposure to ultraviolet (UV) light can have adverse effects on health, including the development of skin cancer, cataracts, and osteoporosis. Earth observation (EO)--based UV index can estimate area-level UV indexes without effort in open-sky environments but can not provide sufficient accuracy for shaded environments. In contrast, conventional methods for monitoring individual-level UV index, such as mobile and wearable UV sensors, face limitations in terms of measurement and usability, presenting challenges for practical long-term usage. To address these issues, we introduce A-UVI, a method that enhances the accuracy of the EO-based UV index by leveraging raw signals from global navigation satellite systems (GNSS). By integrating an EO-based UV index and estimated attenuation ratio, which is estimated with raw GNSS signals, our method especially improves estimation accuracy in shady environments affected by obstructions. We evaluated our proposed method on data collected by different types of GNSS receivers in different mobility scenarios encompassing a diverse range of contexts and observation areas over the course of three days. Our evaluation showed that the A-UVI estimates the UV index with a precision exceeding existing methods by at least 44.25\%, achieving 5.53 times higher estimation accuracy in forest environments. We also confirmed that A-UVI is compatible with GNSS receivers in consumer-grade smartphones and has an average accuracy of 23% better than the baseline EO-based method. Our findings demonstrate that utilizing raw GNSS signals enables the accurate estimation of the UV index in various conditions, including in shaded areas, without the need for particular measurement actions or devices. This marks a significant advancement in enabling passive individual-level UV exposure monitoring and adaptive UV exposure management beyond simple exposure tracking.
Paper :
A-UVI: GNSS-Assisted EO-based UV Index Estimation Method for Individual-level Precise UV Exposure Assessment
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