Presentation

In 2019, the European Space Agency (ESA) has published a Call for Tender (CfT) for a 4-year project. The purpose is the measurements of atmospheric conditions above different site around the world thanks to a measurement station called CATM-GSE (Clouds Aerosols and Turbulence Monitoring – Ground Support Equipment) to assess the optical telecommunication links availability. This campaign should last at least for two years. These measurements will be then correlated to long-term satellite databases to assess the possibility of using these later for a long-term site characterization without using in-situ measurements.

The CNRS/OCA/Lagrange Lab. has gathered a consortium called ANAtOLIA (Atmospheric moNitoring to Assess the availability of Optical LInks through the Atmosphere) and a project has been proposed and then accepted by ESA. The main objectives of the ANAtOLIA project are:

• To design, manufacture, procure and assembly a self-standing and autonomous ground support equipment precisely measuring the clouds, aerosols and turbulence conditions for atmospheric transmission characterization.
• To install and commission this equipment on selected ground location in ESA member states or in their vicinity.
• To monitor continuously local atmospheric conditions for a sufficiently long period (³24 months).
• To correlate these local ground measurements with long-terms satellites database. The purpose is to validate these databases in order to use them for longer term site characterizations.

The CATM-GSE ANAtOLIA station has been developed and now under onsky tests at the Calern Observatory since Feb. 2022. The ANAtOLIA station consists of the following set of complementary instruments:

• The Generalized Monitor of Turbulence, dedicated to the optical turbulence monitoring will be design and manufacture by the Lagrange laboratory (CNRS/UCA/OCA) and will be able to measure during both daytime and nighttime the turbulence conditions.The Reuniwatt SkyInsight InfraRed Camera is a wide field sky imager which monitors, 24h/day the cloud conditions (coverage, thickness, …) of the entire sky.
• The SkyInsight is an off the shelf instrument already validated and confirmed.
• The Cimel CE318-T multispectral photometer is dedicated to the monitoring of aerosols conditions during both daytime and nighttime. As for the SkyInsight, the CE318-T is an off the shelf instrument worldwide validated and confirmed.

For this ANAtOLIA project, the CNRS/OCA/Lagrange Lab. has gathered a consortium called ANAtOLIA, composed of European research laboratories, industrials and companies has shown on the organigram below. The partners of the consortium are:

• CNRS-OCA-Lagrange Laboratory
• CNRS-LatmosAirbus DS FR (ADS-FR)
• Thales Alenia Space (TAS)
• Norway University (NTNU)
• CNRS-ICARE/AERIS
• OCA-Lagrange Technical Direction
• Reuniwatt
• Cimel

Initially, ESA planned to have a monitoring campaign above 8-10 sites around the world for a 2M€ budget. Considering the instruments needed to measure atmospheric parameters with the best possible precision, and the work to be delivered to achieve the ESA goals, the ANAtOLIA consortium has considered this budget too low for such a number of sites.

Therefore, the consortium and ESA agreed to reduce the number of sites to monitor to 4 and to limit their location in Europe. To monitor this site, the consortium will build 2 portable CATM-GSE station to visits 3 sites as follow:

• 1 site for a 2-year campaign
• 2 sites for a 1-year campaign successively

The 4th monitored site will be the Calern Observatory, already hosting the Calern Atmospheric Turbulence Station (CATS) since 2015.