The four small satellites in the CO3D constellation (Constellation Optique en 3D) are set to map the globe in 3D from low Earth orbit starting in 2025, to serve public and private sector needs.

Key figures

• 4 satellites in constellation
• 300 kg: mass of each satellite
• 1-m elevation accuracy
• 50-cm spatial resolution

Key milestones

• June 2025: Launch of constellation and start of in-orbit commissioning
• January 2026: Start of demonstration phase
• June 2027: End of demonstration phase and start of commercial phase
• 9 December 2020: CO3D launch contract awarded to Arianespace with Vega C
• 8 July 2019: CNES selects Airbus Defence & Space to build satellites

Project in brief

To succeed the stereoimaging capability provided by the Pleiades satellites, CNES has conceived the CO3D programme to deliver geographic data covering the entire globe in three dimensions. By surveying the same area of interest from different viewing angles, it’s possible to generate 3D maps. Image acquisition by pairs of satellites also enables synchronous measurements to render moving objects (e.g. vehicles or waves), while having two pairs of satellites augments revisit capability and coverage of wide survey areas.

Each CO3D satellite will have a unique optical instrument with a spatial resolution of approximately 50 cm in the red, green and blue visible bands and in the near-infrared. After processing on the ground, their data will yield 3D maps of all of Earth’s land surfaces in the form of a digital surface model (DSM) with an elevation resolution of approximately one metre. DSM production will cover some 25 million square kilometres annually, a rate unrivalled anywhere in the world at such a high level of accuracy. DSMs will be used by the military and by civil society, as well as opening up new commercial prospects for start-ups and established firms alike. The entire globe is expected to be covered in five years and for certain categories of user—glaciologists, snow scientists, geologists, etc.—zones of interest will be remodelled every few months.

On 8 July 2019, CNES awarded the CO3D contract to Airbus Defence & Space, which is currently building the satellites around a new spacecraft bus weighing about 300 kilograms equipped with electric thrusters for in-orbit manoeuvres and a new generation of reaction wheels offering a high degree of agility. The instruments will use new optics to acquire imagery and offer the ability to pre-process it on board and then downlink it to ground at very high data rates.

CNES’s role

CNES established the CO3D programme and is responsible for the quality of imagery and 3D products. To this end, it is developing 2D and 3D product processing chains that will form part of the ground segment, as well as the Image Quality unit devoted to radiometric and geometric image calibration.

Contacts

Project Leader
Lionel Perret
E-mail: lionel.perret at cnes.fr

System Performance
Laurent Lebegue
E-mail: laurent.lebegue at cnes.fr

Continental Biosphere subject matter expert
Philippe Maisongrande
E-mail: philippe.maisongrande at cnes.fr

Water Cycle subject matter expert
Delphine Leroux
E-mail: delphine.leroux at cnes.fr