As part of its support for the preparation of future surface–current observation missions, CNES is funding the PIRATA–ODYSEA experiment, dedicated to studying ocean surface circulation in the equatorial Atlantic. Launched in March 2025 for several months, the campaign aims to bridge the gap between satellite observations—which target currents within the uppermost meter of the ocean—and the in-situ instruments typically used for calibration/validation (CAL/VAL), which operate at depths of several meters. The campaign also seeks to better characterize the diurnal variability of currents, a key source of aliasing for satellite measurements. The dataset comprises 40 Hereon Lagrangian surface drifters deployed along the equatorial line of the Atlantic Ocean.

The PIRATA-ODYSEA experiment is funded by CNES as part of its support for future satellite missions measuring surface currents and follows earlier CNES-supported projects such as STREAM and COURANTS. It is complemented by instruments provided in 2023 by the INSU national oceanographic facility, as well as additional sensors funded by IRD and the LEFE/GMMC program and installed on the three equatorial PIRATA moorings.