CHEOS: behind the scenes of the Chinese Earth observation system

The Gaofen constellation: a heterogeneous fleet

Satellites with complementary capabilities

The CHEOS programme successfully launched seven civilian satellites between 2010 and 2020, all named Gaofen (GF)[reference:3]. Each satellite carries different sensors to cover the full spectrum of needs: high-resolution optical, synthetic aperture radar (SAR), hyperspectral, and even laser altimetry.

GF-1 and GF-6 carry both 2-metre panchromatic cameras and 8-metre multispectral cameras, dedicated to land-use monitoring[reference:4]. GF-3 is equipped with a dual-polarisation C-band radar capable of reaching a resolution of 1 metre, mainly for monitoring maritime targets[reference:5]. GF-5 carries six sensors, including a hyperspectral camera and a directional polarisation camera, for the study of the environment and climate: aerosols, clouds and greenhouse gases[reference:6]. Finally, GF-7 has a laser altimeter for three-dimensional mapping and natural resource surveying[reference:7].

Table of the main Gaofen satellites

The table below summarises the characteristics of the main satellites in the civilian Gaofen series, with their resolutions and preferred application areas.

Technical capabilities on a par with the best systems

High spatial, spectral and temporal resolution

CHEOS aims to build an Earth observation system with high spatial, temporal and spectral resolution, capable of operating day and night and in all weather conditions[reference:8]. The spatial resolution of Gaofen satellites reaches levels comparable to the best Western systems: GF-2 offers a panchromatic resolution of 0.8 metre, and some satellites in the military series (GF-11) are said to go below 0.5 metre[reference:9].

The hyperspectral resolution of GF-5 makes it possible to quantitatively describe the physical properties of land cover using hundreds of narrow spectral bands, from ultraviolet to near-infrared[reference:10]. Temporal resolution, essential for tracking subtle changes, is ensured by the diversity of orbits and the complementarity of sensors.

Concrete and strategic applications

Resources, disasters and security

Gaofen data feed applications in fields as varied as urban planning, disaster monitoring, agricultural assessment and environmental protection[reference:11]. The programme aims to provide real-time, all-weather observation data for disaster prevention and emergency response, particularly for landslides, typhoons and torrential rain[reference:12].

CHEOS also plays a key role in the “Belt and Road” initiative, by providing observation data for partner countries, and in nationwide environmental monitoring[reference:13]. Control of these data reduces China's dependence on foreign commercial providers and strengthens its strategic autonomy[reference:14].

The commercial ecosystem: SuperView Neo and beyond

A private offering in full expansion

Beyond the civilian CHEOS programme, China has developed a dynamic commercial ecosystem. The SuperView Neo constellation (四维高景), operated by China Siwei (a CASC subsidiary), combines optical and radar satellites to offer high-resolution services. SuperView Neo 2 (四维高景二号) is a synthetic aperture radar satellite capable of a resolution below 1 metre, operating day and night and in all weather conditions[reference:15].

SuperView Neo 3 (四维高景三号) is presented as China's first optical surveillance satellite combining a swath of more than 130 kilometres and a resolution of 0.5 metre, enabling coverage of vast areas with frequent revisit[reference:16]. This commercial constellation complements the public CHEOS offering and demonstrates the industrial maturity of the Chinese space sector.

Sovereignty and international cooperation

A data policy different from Copernicus

Unlike Copernicus, whose Sentinel data are freely accessible to all, CHEOS does not practise full openness. Gaofen data are distributed under controlled arrangements, depending on users and uses. This approach reflects the Chinese conception of geospatial data sovereignty, considered a strategic asset.

Nevertheless, China is actively developing international cooperation. The CNSA has presented CHEOS at international forums, particularly in Latin America, and offers partnerships within the framework of the space “Belt and Road” initiative[reference:17]. This strategy aims to position CHEOS as an alternative to Western systems for emerging countries.

Key takeaways

CHEOS is no longer an emerging programme: it is an operational reality that places China among the major powers in Earth observation. With its seven civilian Gaofen satellites, its optical, radar and hyperspectral capabilities, and its rapidly expanding commercial ecosystem, China now has a complete infrastructure to monitor its territory and export its expertise.

The comparison with Copernicus is illuminating: where Europe relies on openness and free data, China prioritises strategic control and sovereignty. These two models do not directly oppose each other, but they outline two visions of geospatial data governance on a global scale. The question is no longer whether China can compete with Copernicus, but under what terms and with which partners it will do so.