The major mission of CFOSAT (Chinese-French Oceanic SATellite) is to obtain the global sea wave spectrum, wind filed and polar sea ice characteristics. CFOSAT could further strengthen the scientific understanding of the changing pattern of marine dynamic environment, improve the accuracy and timelines of catastrophic sea conditions such as huge wave, tropical storms and storm surges, and provide foundational data for the study of global climate change by obtaining polar ice sheet data.

        CFOSAT is jointly developed by China National Space Administration (CNSA) and French Centre National d'etudes Spatiales (CNES). China provides satellite carrier, launch, measurement and control, satellite platform and fan-beam rotation scatterometer (SCA) and Beijing, Sanya, Mudanjiang ground station and data processing centers. France provides SWIM (Surface Waves Investigation and Monitoring), digital RF components and Arctic ground stations and data processing centers. According to the agreement, the payload of SCAT and the data belong to CNSA. The payload of SWIM and the data belong to CNES. The CFOSAT Scientific Data Management Plan states that Level-1 and Level-2 data products are free for non-commercial use.

The primary objective of CFOSAT is to monitor the global sea wave spectrum, sea surface wind, and polar sea ice characteristics at the orbit altitude of 500 km or so. CFOSAT could further improve the observation and prediction ability of the two countries and international scientific communities on marine meteorology and the understanding of air-sea interactions, forecasting ocean waves and monitoring ocean conditions. Also, it plays a role in the process of building atmospheric-ocean interface model, analyzing the role of waves in atmospheric-ocean interface, studying polar floes and polar ice characteristics. CFOSAT will also be used for the estimation of land surface parameters for better understanding ocean dynamics and climate changes. CFOSAT will enhance the ocean remote sensing capabilities of China and France, and lay the foundation for the cooperation of application study and the research of global climate change, which is of great significance and has far-reaching impact.

As the first satellite jointly developed by China and France, CFOSAT will achieve the large-area and high-precision observation of ocean surface wind and waves simultaneous for the first time in the world. SCAT is the first rotating fan-bean scatterometer for global ocean vector wind observations. The antenna and rotation part have a small weight and moment of inertia which means it has less disturbance to the platform during operation and suitable for small satellite. SWIM is the first space radar that is dedicated to the measurement of ocean waves directional spectrum through the six incidence beams real-aperture radar way. The combination of SCAT with fan-beam and SWIM with multi-incidence beams is of great significance for studying the process of marine dynamic environment and surface scattering characteristics.

CFOSAT is included in the medium and long-term planning of Chinese and French cooperation plan and is a major contributor to the space climate observing platform together with the marine series satellites. The data will be used for global climate change research which facilitating the implementation of the Paris Agreement signed at the 21st United Nations Global Climate Change Conference.


Sensor specification

SWIM (sea surface wave monitoring)


13.575 GHz

Incidence angles (on ground)


Resolution cell

 50x50 km2~ 70x70 km2

Beam retrieval Accuracy (at nadir)

Significant ocean wave: 10% or 0.5m

Wind speed: ±2m/s or 10% (@ max value)

Wavelength range


Wave direction accuracy


Power density spectrum accuracy of wave height

15% (target 10%) @ 3dB peak width range

Average radar backscattering coefficient

Absolute accuracy: ±1dB

Relative accuracy:  ±0.1dB

SCAT (sea surface wind monitoring)

Center frequency


Swath width


Resolution cell


Backscattering coefficient measurement accuracy

0.5dB( wind speed @ 6~24m/s)

1dB(wind speed @ 4~6m/s)

Measurement range


Wind speed accuracy

 ±2m/s or 10% ( @ max value) (4~24m/s)

Wind direction accuracy


National Satellite Ocean   Application Service