IPRAL is an automatic multi-channel lidar manufactured by Gordien Strato in partnership with Raymetrics. Lidar observation involves emitting a vertical laser pulse towards the sky. The backscattered optical signal is then collected by a telescope and analyzed to deduce the optical properties of the scattering medium, such as the optical thickness of cirrus clouds and aerosols.

Deployed since 2015 at the SIRTA observatory on the campus of the École Polytechnique, IPRAL is mainly operated by the LMD. With its laser available at wavelengths of 355, 532 and 1064nm, IPRAL is dedicated to the study of dynamic processes in a semi-urban environment to improve the understanding of interactions between clouds, radiative and dynamic processes, and to develop new remote sensing methods for future space observations.

In 2020, the instrument was moved to the new SIRTA2020 building of the observatory thanks to the expertise of no less than seven industrial service providers. Since the end of February 2024, the IPRAL Lidar has been operational again thanks to its new laser.

The IPRAL Lidar is involved in the commitments of the ACTRIS research infrastructure to provide regular continuous data to the Copernicus program’s Earth observation services.