Publicações

The Telescope Array (TA) detector located in the southwestern desert of the State of Utah is the largest ultra-high energy cosmic ray experiment in the Northern Hemisphere. The TA detector has been a unique facility for studying downward TGFs and has reported several discoveries over the past few years that allowed us to better understand the Terrestrial Gamma-ray Flashes (TGF) phenomena. The surface detector array part of the TA experiment, used in these observations, is composed of 507 scintillator detectors on a 1.2 km square grid covering a 700-kilometer square area, 1400 m above sea level. New instrumentations have been added at the Telescope array site to study the optical emission of lightning in association with TGFs. In this work, we present optical emission observations of lighting discharges in association with multiple downward-directed TGFs as observed at the Telescope Array detector. Results from this study allow us to further the understanding of the initiation and propagation mechanism of TGFs. Moreover, they enhance our capability to compare satellite optical emissions of upward-directed TGFs with those of downward-directed TGFs.

The Telescope Array (TA) detector located in the southwestern desert of the State of Utah is the largest ultra-high energy cosmic ray experiment in the Northern Hemisphere. The TA detector has been a unique facility for studying downward TGFs and has reported several discoveries over the past few years that allowed us to better understand the Terrestrial Gamma-ray Flashes (TGF) phenomena. The surface detector array part of the TA experiment, used in these observations, is composed of 507 scintillator detectors on a 1.2 km square grid covering a 700-kilometer square area, 1400 m above sea level. New instrumentations have been added at the Telescope array site to study the optical emission of lightning in association with TGFs. In this work, we present optical emission observations of lighting discharges in association with multiple downward-directed TGFs as observed at the Telescope Array detector. Results from this study allow us to further the understanding of the initiation and propagation mechanism of TGFs. Moreover, they enhance our capability to compare satellite optical emissions of upward-directed TGFs with those of downward-directed TGFs.

Measuring socioeconomic indices at the scale of regions or countries is required in various contexts, in particular to inform public policies. The use of Deep Learning (DL) and Earth Observation (EO) data is becoming increasingly common to estimate specific variables like societal wealth. This paper presents an end-to-end framework DeepWealth that calculates such a wealth index using open-source EO data and DL. We use a multidisciplinary approach incorporating satellite imagery, socio-economic data, and DL models. We demonstrate the effectiveness and generalizability of DeepWealth by training it on 24 African countries and deploying it in Madagascar, Brazil and Japan. Our results show that DeepWealth provides accurate and stable wealth index estimates with an R2 of 0.69. It empowers computer-literate users skilled in Python and R to estimate and visualize well-being-related data. This open-source framework follows FAIR (Findable, Accessible, Interoperable, Reusable) principles, providing data, source code, metadata, and training checkpoints with its source code made available on Zenodo and GitHub. In this manner, we provide a DL framework that is reproducible and replicable.