Upgrading and expanding the observation system
Maintaining an observation network in an operational condition is accompanied by multi-annual system regeneration programmes in order to anticipate programmed obsolescence and reduce the cost of ownership by streamlining systems. Renewing surface networks continued in 2017 with the deployment of 140 automatic Mercury ground measurement stations and gradual replacement of mechanical anemometers with ultrasonic wind sensors. This initiative will continue into 2018 and will be complemented by the onset of automation of the Réseau climatologique d’État (RCE - French Climatological Network). Automation of the RCE consists of replacing daily readings carried out by volunteer operators with automatic stations recording temperature and rainfall.
In expansion for over thirty years, the radar network has reached its target size with 40 devices operating in mainland France and overseas territories. Two new radar sites were created in France in 2017, one in Saint-Rémy (X-band) and the other in Ajaccio (C-band), completing the network. A regeneration programme for the radar network is committed to replacing 1 to 2 radars per year. In 2017, the radar in Nancy was replaced by a C-band dual polarisation radar by the company Selex.
Recent automation of the altitude network is yet to reach its target size. Two new automatic radiosonde systems will be rolled out on the island of Réunion in the first quarter of 2018, and in Tahiti in the second quarter. An aerosol lidar network was rolled out in 2016. A regeneration programme for the altitude network programme should therefore begin by 2020 to replace the first helium robot-probes with hydrogen robot-probes in order to reduce ownership costs.