In October 2020, the LaMMA Consortium carried out a field measurement campaign in the Southern Ligurian Sea (SLS) as part of the DDR20 – Drifter Demonstration and Research 2020 experiment. Organized by CMRE and supported by several EU-funded projects (SICOMAR plus, JERICO-S3, SINAPSI, and IMPACT), the campaign focused on the deployment of CODE drifters (Davis, 1985; Poulain, 1999). 

The drifters used were specifically acquired by LaMMA through the IMPACT project. Designed to monitor surface currents in the upper meter of the water column while minimizing wind influence, these were MAXO-manufactured CODE models equipped with SPOT Globalstar TRACE modules. The modules feature high-accuracy GPS receivers (<10 m) and transmit position data every 5 minutes, with an estimated velocity accuracy of around 3 cm/s.

A total of 26 drifters were deployed over a few hours, arranged in a 3 km × 3 km square grid in waters about 100 meters deep (centered at Lat: 43°16′N, Lon: 10°14′E). Five were recovered within 1 to 3 days, while the rest eventually beached after drifting for several days. Drifters operating near the coast used cellular networks to transmit data, whereas those farther offshore switched to satellite communication. The resulting dataset spans from October 8 to November 8, 2020, with positions recorded at 5-minute intervals. Some gaps are present due to occasional transmission issues or device malfunctions.

This dataset supports the validation and performance analysis of HF radar measurements in coastal areas, as discussed in Doronzo et al. (2025).

References:

•  Davis, R.E. (1985). Drifter observations of coastal surface currents during CODE: The method and descriptive view. Journal of Geophysical Research: Oceans, 90(C3), 4741–4755. https://doi.org/10.1029/JC090iC03p04741
• Poulain, P.-M. (1999). Drifter observations of surface circulation in the Adriatic Sea between December 1994 and March 1996. Journal of Marine Systems, 20(1–4), 231–253. https://doi.org/10.1016/S0924-7963(98)00084-0
• http://interreg-maritime.eu/web/impact
• Doronzo, B.; Bendoni, M.; Taddei, S.; Boccacci, A.; Brandini, C. Validating HF Radar Current Accuracy via Lagrangian Measurements and Radar-to-Radar Comparisons in Highly Variable Surface Currents. Remote Sens. 2025, 17, 1243. https://doi.org/10.3390/rs17071243