In August last year, CNES and ISRO committed to developing and building a constellation of satellites carrying telecommunications and radar and optical remote-sensing instruments, constituting the first space-based system in the world capable of tracking ships continuously.

After a successful design phase led by a joint team of ISRO-CNES, the satellite is now set to enter its development phases in the coming months, the official said.

The constellation of maritime surveillance satellites for the Indian Ocean Region, to be jointly launched by India and France, will be able to trace illegal spillage of oil by ships, a senior French space agency CENS official said on Sunday.

In August last year, CNES and ISRO committed to developing and building a constellation of satellites carrying telecommunications and radar and optical remote-sensing instruments, constituting the first space-based system in the world capable of tracking ships continuously.

The monitoring centre will be based in India, the official added.

"With a revisit capability (of the satellites), this makes possible to task acquisitions several times a day. It will also be able to detect oil slicks and trace their origin," the official said.

The main purpose of this is to trace illegal spillage of oil by ships. The Indian Ocean Region has several Sea Lanes of Communication (SLOC) and used by many ships every day.

The satellites will be operated jointly by France and India to monitor ships in the Indian Ocean.

The system will also cover a wide belt around the globe, benefiting a broad range of French economic interests, the official said.

Parts of the satellites will be built in both the countries and launched from India, he added.

CNES and the Indian Space Research Organisation (ISRO) are also operating a number of climate-monitoring satellites together.

'Trishna', a highly precise thermal infrared observer, will also be part of the fleet of Indo-French satellites.

After a successful design phase led by a joint team of ISRO-CNES, the satellite is now set to enter its development phases in the coming months, the official said.

"It will provide continuous thermal monitoring at high resolution, its unmatched capabilities serving precious applications ranging from sustainable agriculture to drought forecasting and monitoring of urban heat islands," the official said.

France and India are also collaborating on the Gaganyaan, India's first manned space mission.

France will also be part of ISRO's mission to Venus, the official added.