2 Chinese Earth observation satellites put into service

Two Chinese Earth observation satellites, the Gaofen-5 and Gaofen-6, were officially put into service on Thursday after completing in-orbit tests.

A high-resolution camera on the Gaofen-6 satellite took this photo of the new Beijing Daxing International Airport. [Photo/China Daily]

During the tests, the two satellites provided precise data on environmental monitoring, natural resources and natural disasters, according to China's State Administration of Science, Technology and Industry for National Defense (SASTIND) and China's National Space Administration (CNSA).

Zhang Kejian, vice minister of industry and information technology and head of SASTIND and CNSA, said at a press conference that after the launch of the Gaofen-7 satellite later this year, China will complete the construction of its space-based Earth observation system with seven high-resolution satellites.

Launched on May 9, 2018, Gaofen-5 is the first China-developed satellite that can monitor air pollution. It can dynamically reflect the state of air pollution in China through the monitoring of air pollutants, greenhouse gases and aerosols.

With a designed life of eight years, Gaofen-6 was launched on June 2, 2018, and can provide high-resolution images covering a large area of the Earth. Its data can be applied in monitoring natural and agricultural disasters, estimating crop yields and surveys of forest and wetland resources.

The Gaofen-5 and Gaofen-6 will form a constellation with other Gaofen satellites in orbit.

Gaofen means "high resolution" in Chinese. Since the Gaofen project began in 2010, China has had an increasingly clearer view of the planet.

Launched in April 2013, the Gaofen-1 can cover the globe in just four days.

The Gaofen-2, sent into space in August 2014, is accurate to 0.8 meters in full color and can collect multispectral images of objects greater than 3.2 meters in length.

The Gaofen-4, launched in late 2015, is China's first geosynchronous orbit high-resolution optical imaging satellite.

The Gaofen-3, launched in August 2016, is China's first synthetic aperture radar-imaging satellite.

Last July, China used the Gaofen-3 and Gaofen-4 for emergency monitoring of Typhoon Maria. The two satellites provided data assistance for disaster alerts, rescue and assessment.

The Gaofen project has helped reduce China's dependence on foreign remote sensing satellite data.