Hubbry Logo
GaofenGaofenMain
Open search
Gaofen
Community hub
Gaofen
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Gaofen
Gaofen
Gaofen
View on Wikipedia
from Wikipedia

Gaofen Weixing
高分
Gāo Fēn
Program overview
CountryChina
StatusActive
Program history
First flight26 April 2013
Last flight15 October 2024
Successes34
Failures1
Launch sites
Vehicle information
Launch vehicles

Gaofen (Chinese: 高分; pinyin: Gāofēn; lit. 'high resolution') is a series of Chinese high-resolution Earth imaging satellites launched as part of the China High-resolution Earth Observation System (CHEOS) program.[1][2] CHEOS is a state-sponsored, civilian Earth-observation program used for agricultural, disaster, resource, and environmental monitoring. Proposed in 2006 and approved in 2010, the CHEOS program consists of the Gaofen series of space-based satellites, near-space and airborne systems such as airships and UAVs, ground systems that conduct data receipt, processing, calibration, and taskings, and a system of applications that fuse observation data with other sources to produce usable information and knowledge.[2][3]

Although the first seven Gaofen satellites and their payloads have been heavily detailed, little to no details on Gaofen 8 and later satellites have been revealed prompting suggestions that Gaofen satellites may be dual purpose supporting both civilian and military missions.[2][4][5][6][7]

In 2003, the China National Space Administration (CNSA) agreed with Roscosmos to share Gaofen data for data from Russia's Earth observation satellites of similar capability. This agreement was expanded in August 2021 when leaders from BRICS space agencies agreed to share space-based remote sensing data.[8]

Notable satellites

[edit]

Gaofen-5

[edit]

Gaofen-5 has been lauded as the "flagship of the environment and atmosphere observation satellite in the CHEOS program". Launched on 8 May 2018 from Taiyuan Satellite Launch Center (TSLC) into Sun-synchronous orbit, Gaofen-5 carries six payloads: an Advanced Hyperspectral Imagery sensor (AHSI), Atmospheric Infrared Ultraspectral Sensor (AIUS), Directional Polarization Camera (DPC), Environment Monitoring Instrument (EMI), Greenhouse-gases Monitoring Instrument (GMI), and Visual and Infrared Multispectral Sensor (VIMS).[2][9]

The Advanced Hyperspectral Imagery (AHSI) sensor payload aboard Gaofen-5 claims to be the first space-based hyperspectral imaging sensor utilizing both convex grating spectrophotometry and a three concentric-mirror (Offner) configuration.[10] The AHSI uses spectrophotometry to measure the light spectra reflected, transmitted, or emitted by an imaged object to detect or identify objects on the ground.[10] In civilian applications, the AHSI allows analysts to conduct environmental monitoring and resource discovery while in a military application would allow analysts to detect and identify an adversary's equipment or spot non-multi-spectral camouflage.[10][11][12] AHSI has a 30 meter spatial resolution and 5 nanometer spectral resolution in the visible, near-infrared (NIR), and short-wave infrared (SWIR) wavelength ranges.[12]

The Atmospheric Infrared Ultraspectral Sensor (AIUS) payload aboard Gaofen-5 is China's first hyperspectral occultation spectrometer meaning it measures the spectra of imaged atmospheric particles between the sensor and the Sun.[13][14] AIUS allows scientists to monitor atmospheric circulation by tracing H
2O (water vapor), temperature, pressure, and various carbon and halogen-containing gas pollutants such as chlorofluorocarbons (CFCs), dinitrogen pentoxide, and chlorine nitrate.[14][15] A Michelson interferometer, AIUS images wavelengths between 2.4 and 13.3 micrometers (near to mid-wave infrared) at a 0.3 centimeter resolution and a ±10° field of view.[14]

Gaofen-5's Directional Polarimetric Camera (DPC) is China's first space-based multi-angle polarimetric camera.[9] Prior to GF-5's launch, in September 2016, China had experimented with polarimetric imaging in 2016 aboard the Tiangong-2 space laboratory and launched its Cloud and Aerosol Polarimetric Imager (CAPI) aboard TanSat in December of that year.[9][16] CAPI imaged clouds within 670 and 1640 nanometer channels but was restricted to fixed-angle imaging. The DPC aboard Gaofen-5 enables atmospheric spectroscopy in three polarized bands (90, 670, and 865 nm; polarized at 0°, 60°, and 120°) and five non-polarized bands (443, 565, 763, 765, and 910 nm), all wavelengths from green to near-infrared (NIR). A step motor rotates the 512 × 512 pixel charge-coupled device (CCD) imager ±50° providing a 1,850 km swath of imagery at 3.3 km resolution.[9][17]

Satellites

[edit]

Since the program's start in 2013, the People's Republic of China has launched 32 Gaofen-series satellites with only one launch failure. Jilin-1 satellites described as 'Gaofen' are not part of the government's Gaofen series, rather are described as having high resolution (Chinese: 高分; pinyin: Gāofēn).[18]

Designation Launch date
(UTC) 		Payloads Orbit Orbital apsis Inclination SCN COSPAR ID Launch vehicle Launch site Status
Gaofen 1 26 April 2013 2m PAN, 8m MSI, 4x 16m WFV MSI SSO 632.8 km × 662.7 km 98.1° 39150 2013-018A Long March 2D Jiuquan SLC Operational
Gaofen 2 19 August 2014 0.8m PAN, 3.2m MSI SSO 630.5 km × 638.0 km 97.7° 40118 2014-049A Long March 4B Taiyuan SLC Operational
Gaofen 8 26 June 2015 EO SSO 501.7 km × 504.5 km 97.6° 40701 2015-030A Long March 4B Taiyuan SLC Operational
Gaofen 9-01 14 September 2015 EO SSO 624.5 km × 671.3 km 97.8° 40894 2015-047A Long March 2D Jiuquan SLC Operational
Gaofen 4 28 December 2015 50m VIS, 400m MWIR GEO 35,782.4 km × 35,806.4 km 0.1° 41194 2015-083A Long March 3B Xichang SLC Operational
Gaofen 3 9 August 2016 C-band SAR SSO 757.9 km × 758.8 km 98.4° 41727 2016-049A Long March 4C Taiyuan SLC Operational
Gaofen 10 31 August 2016 Unknown SSO (planned) N/A N/A N/A 2016-F01 Long March 4C Taiyuan SLC Launch failure[19]
Gaofen 1-02 31 March 2018 2m PAN, 8m MSI, 4x 16m WFV MSI SSO 645.4 km × 649.0 km 97.9° 43259 2018-031A Long March 4C Taiyuan SLC Operational
Gaofen 1-03 31 March 2018 2m PAN, 8m MSI, 4x 16m WFV MSI SSO 642.9 km × 651.9 km 97.9° 43260 2018-031B Long March 4C Taiyuan SLC Operational
Gaofen 1-04 31 March 2018 2m PAN, 8m MSI, 4x 16m WFV MSI SSO 644.3 km × 650.5 km 97.9° 43262 2018-031D Long March 4C Taiyuan SLC Operational
Gaofen 5 8 May 2018 303km POL MSI, 0.3cm HSI, 30m HSI SSO 706.2 km × 707.0 km 98.3° 43461 2018-043A Long March 4C Taiyuan SLC Operational
Gaofen 6 2 June 2018 MSI SSO 641.0 km × 654.3 km 97.9° 43484 2018-048A Long March 2D Jiuquan SLC Operational
Gaofen 11-01 31 July 2018 EO SSO 493.1 km × 512.5 km 97.6° 43585 2018-063A Long March 4B Taiyuan SLC Operational
Gaofen 10R 4 October 2019 Unknown SSO 632.0 km × 634.4 km 97.9° 44622 2019-066A Long March 4C Taiyuan SLC Operational
Gaofen 7 3 November 2019 2x 0.8m PAN, 2.5m MSI SSO 500.7 km × 517.9 km 97.4° 44703 2019-072A Long March 4B Taiyuan SLC Operational
Gaofen 12 27 November 2019 SAR SSO 634.4 km × 636.5 km 97.9° 44819 2019-082A Long March 4C Taiyuan SLC Operational
Gaofen 9-02 31 May 2020 EO SSO 493.9 km × 511.3 km 97.4° 45625 2020-034B Long March 2D Jiuquan SLC Operational
Gaofen 9-03 17 June 2020 EO SSO 491.5 km × 513.9 km 97.4° 45794 2020-039A Long March 2D Jiuquan SLC Operational
Gaofen DUOMO 3 July 2020 EO SSO 635.5 km × 657.6 km 97.9° 45856 2020-042A Long March 4B Taiyuan SLC Operational
Gaofen 9-04 6 August 2020 EO SSO 497.9 km × 506.4 km 94.4° 46025 2020-054A Long March 2D Jiuquan SLC Operational
Gaofen 9-05 23 August 2020 EO SSO 493.5 km × 511.9 km 97.4° 46232 2020-058A Long March 2D Jiuquan SLC Operational
Gaofen 11-02 7 September 2020 EO SSO 500.7 km × 505.2 km 97.4° 46396 2020-064A Long March 4B Taiyuan SLC Operational
Gaofen 13 11 October 2020 50m VIS, 400m MWIR GEO 35,782.5 km × 35,806.1 km 0.2° 46610 2020-071A Long March 3B Xichang SLC Operational
Gaofen 14 6 December 2020 EO SSO 492.9 km × 198.4 km 97.4° 47231 2020-092A Long March 3B/G5 Xichang SLC Operational
Gaofen 12-02 30 March 2021 SAR SSO 634.7 km × 636.6 km 97.9° 48079 2021-026A Long March 4C Jiuquan SLC Operational
Gaofen 5-02 7 September 2021 303km POL MSI, 0.3cm HSI, 30m HSI SSO 705.4 km × 710.2 km 98.2° 49122 2021-079A Long March 4C Taiyuan SLC Operational
Gaofen 11-03 20 November 2021 EO SSO 498.6 km × 504.8 km 97.4° 49492 2021-107A Long March 4B Taiyuan SLC Operational
Gaofen 3-02 22 November 2021 C-band SAR SSO 757.5 km × 759.2 km 98.4° 49495 2021-109A Long March 4C Jiuquan SLC Operational
Gaofen 3-03 6 April 2022 C-band SAR SSO 757.8 km × 758.9 km 98.4° 52200 2022-035A Long March 4C Jiuquan SLC Operational
Gaofen 12-03 27 June 2022 SAR SSO 633.3 km × 367.1 km 98.0° 52912 2022-069A Long March 4C Jiuquan SLC Operational
Gaofen 5-01A 8 December 2022 HSI SSO 706.1 km × 709.0 km 98.1° 54640 2022-165A Long March 2D Taiyuan SLC Operational
Gaofen 11-04 27 December 2022 EO SSO 498.6 km × 504.8 km 97.4° 54818 2022-176A Long March 4B Taiyuan SLC Operational
Gaofen 13-02 17 March 2023 Unknown GTO 35,788.4 km × 35,802.1 km 3.0° 55912 2023-036A Long March 3B/E Xichang SLC Operational
Gaofen 12-04 20 August 2023 SAR SSO 626 km × 630 km 97.9° 57654 2023-132A Long March 4C Jiuquan SLC Operational
Gaofen 11-05 19 July 2024 EO SSO Long March 4B Taiyuan SLC Operational
Gaofen 12-05 15 October 2024 SAR SSO Long March 4C Jiuquan SLC Operational
Table data sourced from previously cited references, CelesTrak, N2YO, NASA, and the U.S. Space Force

See also

[edit]

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Gaofen

View on Grokipedia
from Grokipedia
Gaofen (高分, meaning "high resolution") is a series of civilian high-resolution satellites developed by as the space-based component of the China High-resolution Earth Observation System (CHEOS), a national program focused on acquiring detailed data for land resources, , and . The initiative began with the launch of Gaofen-1 in April 2013 from the , marking China's first medium-resolution optical satellite in the CHEOS framework with a design life of eight years and capabilities for in . Subsequent satellites have diversified the constellation's functionalities, including Gaofen-2's sub-meter optical for precise mapping, Gaofen-3's C-band for all-weather imaging, and Gaofen-4's for continuous regional surveillance, enabling applications in , disaster relief, ecological assessment, and . By 2025, over a dozen Gaofen satellites have been deployed, significantly bolstering China's autonomous infrastructure with enhanced spatial, spectral, and temporal resolutions, though some advanced models like Gaofen-11 and Gaofen-12 incorporate sensing with limited public details on specifications. While primarily civilian, the high-fidelity data supports broader national priorities including infrastructure development and security, with recent launches such as Gaofen-14 in October 2025 underscoring ongoing expansions for stereo mapping and multi-purpose utility.

Program Overview

Objectives and Scope

The Gaofen program forms a core component of the China High-resolution Earth Observation System (CHEOS), which was approved by the Chinese government in 2010 to develop an autonomous capability for high-resolution . The primary objectives include achieving nationwide coverage with 2-meter resolution in optical and 1-meter resolution in (SAR) , enabling detailed independent of foreign data. This initiative emphasizes indigenous technological development to enhance self-reliant innovation in sensors, platforms, and ground systems, addressing limitations from international export controls on advanced technologies. CHEOS, through the Gaofen satellites, targets applications such as resource surveying, including and mineral exploration; prevention and response; urban and rural planning; and , including monitoring. These goals support major national demands for near-real-time data to inform policy and operational decisions, with SAR capabilities providing all-weather, day-and-night observations to complement optical systems. The program's scope encompasses building a large-scale constellation of dozens of satellites across optical, SAR, hyperspectral, and other specialized types to ensure persistent global coverage, contrasting with reliance on intermittent access to overseas commercial imagery. By integrating space-based assets with stratospheric airships and aerial platforms, CHEOS aims for comprehensive, high-temporal-resolution monitoring to meet civil and economic needs.

Development Framework

The Gaofen program operates under the China High-resolution Earth Observation System (CHEOS), a state-led initiative coordinated by the as the primary oversight body, with satellite development primarily handled by the and technical inputs from the . This structure emphasizes centralized planning and resource allocation to align with national priorities in . Funding and strategic direction derive from China's Five-Year Plans, with foundational support originating in the 11th Plan (2006-2010), which prioritized advancements in space-based infrastructure as part of broader science and technology development goals, enabling initial system design and prototyping phases. Subsequent plans, including the 12th (2011-2015) and 13th (2016-2020), expanded investments to support constellation buildup and application integration. A key policy evolution involves the adoption of (MCF), formalized as a national strategy during the 13th Five-Year Plan, which integrates civilian Gaofen assets with requirements to streamline resource sharing, , and rapid prototyping-to-deployment cycles without separate parallel systems. This approach, directed by the Communist Party of China, has facilitated efficient scaling by leveraging dual-use technologies, though it maintains civilian designation for international optics while enabling defense applications. Gaofen's framework also incorporates selective international dimensions through alignment with the (BRI), promoting data access and cooperative projects with participating nations for applications like disaster monitoring and infrastructure mapping, yet with stringent controls on high-resolution data dissemination to preserve domestic sovereignty and .

Historical Development

Inception and Early Planning

The civilian High-Definition Earth Observation Satellite (HDEOS) program, which laid the groundwork for the Gaofen series, was proposed in to enhance China's independent capabilities in high-resolution , addressing gaps in domestic imaging technology amid reliance on foreign systems. This initiative aimed to integrate space-based, near-space, and airborne platforms for improved spatial, temporal, and spectral resolution in . In May 2010, the Chinese government formally approved the High-resolution System (CHEOS), encompassing the Gaofen satellites as its core orbital component, with the objective of building an autonomous system for applications in mapping, , and . Early planning emphasized surpassing the resolutions of international benchmarks such as NASA's Landsat series (30-meter multispectral) and France's SPOT satellites (10-meter panchromatic), targeting sub-5-meter capabilities, including 2-meter panchromatic imaging for the inaugural Gaofen-1 satellite. From 2006 to 2013, pre-launch prioritized indigenous sensor technologies, payload integration, and compatibility with launch vehicles (such as the for Gaofen-1) to achieve reliable sun-synchronous orbital insertions, while navigating constraints in miniaturizing high-resolution optics and ensuring data processing infrastructure scalability. These efforts were coordinated by the and state agencies, focusing on technological to mitigate external dependencies in precision Earth imaging.

Key Milestones in Launches

The Gaofen program initiated its operational phase with the launch of Gaofen-1 on April 26, 2013, from the aboard a Long March-2D , marking the first satellite in China's Civil High-Resolution System (CHEOS). This optical imaging satellite achieved 2-meter panchromatic and 8-meter multispectral resolution, enabling wide-area land monitoring and establishing the foundation for high-definition Earth observation capabilities. Subsequent launches advanced resolution and versatility, with Gaofen-2 deployed on August 19, 2014, from via Long March-4B, introducing sub-meter (0.8-meter) panchromatic imaging for detailed urban and agricultural applications. The program's diversification began in 2016 with Gaofen-3, China's inaugural civil (SAR) satellite, launched August 10 from on a Long March-4C, providing all-weather, day-night imaging at 1-meter resolution in spotlight mode using C-band multi-polarization. This was followed by Gaofen-5 on May 9, 2018, from aboard Long March-4C, incorporating advanced hyperspectral sensors for atmospheric and with over 300 spectral bands. The constellation expanded rapidly post-2018, incorporating additional optical, SAR, and specialized satellites to enhance revisit times and coverage; by June 2023, 37 Gaofen satellites had been launched under CHEOS, supporting persistent global observation. Recent missions have focused on and advanced maneuvering, exemplified by Gaofen-14 02, a stereo-mapping satellite launched October 26, 2025, from on Long March-3B, which bolsters agile, high-precision topographic data collection for and infrastructure planning. These developments reflect a progression from single-satellite proofs-of-concept to a robust network enabling near-real-time Earth imaging.

Satellite Constellation

Optical Imaging Satellites

The Gaofen program's optical imaging satellites employ visible and near-infrared sensors to deliver high-resolution panchromatic and multispectral imagery, primarily supporting land mapping, resource surveying, and over and adjacent regions. These satellites feature pushbroom or frame cameras capable of sub-meter to multi-meter resolutions, with agile attitude control systems enabling targeted stereo pair acquisition for topographic modeling. Key examples include the Gaofen-1, Gaofen-2, Gaofen-4, Gaofen-6, and Gaofen-7 series, which collectively enhance through constellation coordination, achieving near-daily revisits for priority areas within . Gaofen-1, launched in April 2013, pioneered the series with a panchromatic/multispectral (PMS) camera offering 2-meter panchromatic and 8-meter multispectral resolution across a 60-kilometer swath, complemented by a wide-field (WFVC) at 16-meter resolution for broader 800-kilometer coverage. Subsequent Gaofen-1 variants, including those launched in 2018, expanded the constellation to support 2-day global revisits and finer full-color imaging at 2 meters. Gaofen-2, operational since August 2014, advanced capabilities with a 0.81-meter panchromatic resolution and 3.24-meter multispectral bands (visible to near-infrared) over a 45.3-kilometer swath, facilitating precise urban and agricultural mapping. Gaofen-4, deployed in December 2015 into , provides persistent wide-area surveillance with a 50-meter visible/near- resolution and 400-meter mid-wave , covering up to 400 by 400 kilometers per scene for real-time over eastern . Gaofen-6, launched in June 2018, mirrors Gaofen-1's architecture but incorporates radiometric enhancements for improved data quality in multispectral bands, aiding in estimation and classification. These low-Earth assets synergize with Gaofen-4's stationary vantage for hybrid coverage strategies. Gaofen-7, launched in November 2019, specializes in three-line with forward-view panchromatic resolution better than 0.8 meters, at approximately 0.65 meters, and backward views enabling digital models accurate to 3 meters vertically for 1:25,000-scale mapping. Its agile pointing allows flexible baseline adjustments for pairs up to 20 kilometers wide, supporting and 3D urban modeling. The integrated constellation of these optical satellites yields daily or sub-daily revisits over Chinese territory through orbital phasing and multi-satellite tasking, outperforming single-satellite cycles of 4-5 days.
SatelliteLaunch DateKey Resolutions (PAN/MS)Swath WidthNotable Features
Gaofen-1April 20132 m / 8 m60 km (PMS); 800 km (WFVC)Wide-field complement for regional surveys
Gaofen-2August 20140.81 m / 3.24 m45.3 kmHigh-precision panchromatic for detailed mapping
Gaofen-4December 201550 m (VNIR)400 × 400 kmGeosynchronous for continuous regional monitoring
Gaofen-6June 20182 m / 8 m60 km (PMS); 800 km (WFVC)Enhanced radiometrics over Gaofen-1
Gaofen-7November 2019<0.8 m (stereo PAN)20 km (stereo)Three-line scanner for 3D terrain generation

Synthetic Aperture Radar Satellites

The Gaofen program's (SAR) satellites employ active microwave radar systems to enable imaging independent of weather conditions and sunlight, utilizing the synthetic aperture technique to achieve high spatial resolutions from orbital platforms. These satellites operate primarily in the C-band frequency, which balances penetration through vegetation and atmospheric attenuation with fine detail capture. The core of the SAR component is the Gaofen-3 series, representing China's inaugural civilian high-resolution SAR mission. Gaofen-3, launched on August 10, 2016, via a Long March 4C rocket from the , features a C-band SAR payload with 12 distinct imaging modes, including spotlight, stripmap, and scan modes. In spotlight mode, it attains a resolution of 1 meter, while broader modes offer swaths up to 650 kilometers at coarser resolutions up to 500 meters. The instrument supports multi-polarization configurations, such as single (HH or VV), dual (HH+HV or VV+VH), and full quad-polarization (HH+HV+VH+VV), facilitating detailed scattering analysis. With a design life of 8 years and an orbit at approximately 755 kilometers altitude in , Gaofen-3 marked a technical leap in domestic SAR capabilities, incorporating phased-array antennas for and agile imaging. Subsequent expansions bolstered the constellation's interferometric potential. Gaofen-3B, launched November 30, 2021, and Gaofen-3C, launched August 4, 2022, both employ similar C-band SAR systems optimized for tandem , enabling repeat-pass with baselines suitable for millimeter-scale deformation detection. These variants enhance phase stability and baseline diversity over the prototype, supporting high-precision differential InSAR processing. The series integrates SAR datasets with complementary optical observations from other Gaofen platforms, yielding fused products that combine radar's all-weather attributes with visible-spectrum detail, though SAR remains the primary modality for penetration-limited scenarios. Advancements in the Gaofen SAR fleet reflect iterative improvements in and antenna design, transitioning from single-satellite operations to a networked array for persistent coverage. The full-polarization SAR on Gaofen-3 pioneered domestic civil access to polarimetric techniques, previously dominated by foreign systems like Europe's Sentinel-1. Constellation growth has prioritized and mode versatility, with ongoing refinements in radiometric accuracy exceeding 0.5 dB and geometric precision below 3 meters without ground control.

Hyperspectral and Specialized Satellites

Gaofen-5, launched on May 9, 2018, from aboard a Long March 4C rocket, introduced China's inaugural capabilities within the Gaofen program, primarily through its Advanced Hyperspectral Imager (AHSI). The AHSI operates with 330 contiguous spectral bands across visible, near-, and shortwave wavelengths, achieving a of 5-10 nm and a of 30 m over a 60 km swath width. This configuration supports precise material discrimination, facilitating applications in mineralogical mapping, vegetation health assessment, and detection of atmospheric pollutants like tropospheric via complementary payloads such as the Imager (EMI). A successor, Gaofen-5 02, launched on September 27, 2021, extends these hyperspectral functions with similar , enhancing and coverage for ongoing environmental and resource monitoring. The series' high fidelity, down to 5 nm in key bands, enables sub-pixel level identification of substances, such as distinguishing crop stress in or trace contaminants in , outperforming multispectral systems in analytical accuracy. Additionally, Gaofen-5 incorporates visible and multispectral scanners (VIMS) for , supporting land surface temperature retrieval with resolutions suitable for analysis and . Among specialized variants, Gaofen-4, deployed to on December 28, 2015, via Long March 3B/E, provides persistent real-time surveillance over regions using a visible-light and staring imager with 50 m resolution. This fixed-point capability allows up to three images per minute, integrating thermal channels for night-time and all-weather monitoring of dynamic events like wildfires or maritime movements. Later iterations, such as Gaofen-5 01A launched December 9, 2022, further integrate hyperspectral and thermal sensors, broadening applications to precise atmospheric and ecological analytics.

Technical Specifications

Sensor Technologies and Resolutions

The Gaofen program's optical imaging satellites primarily employ (CCD) or complementary metal-oxide-semiconductor () sensors for panchromatic and multispectral observation. Panchromatic sensors achieve sub-meter resolutions, with Gaofen-2 providing 0.8-meter ground resolution over a 45-48 km swath, while multispectral bands offer 3.2-4 meter resolutions across , red, and near-infrared spectra. Earlier satellites like Gaofen-1 deliver 2-meter panchromatic and 8-meter multispectral resolutions, with later models such as Gaofen-6 maintaining similar high-fidelity panchromatic/multispectral pairs for detailed mapping. These sensors incorporate agile pointing mechanisms to enable and off-nadir acquisitions up to 25 degrees. Synthetic aperture radar (SAR) systems in Gaofen satellites, such as the C-band instrument on Gaofen-3, utilize active phased-array antennas with multi-polarization capabilities (HH, VV, HV, VH) and 12 imaging modes ranging from spotlight high-resolution to wide-swath ScanSAR. Resolutions reach 1 meter or better in azimuth and range via synthetic aperture techniques and beam steering, enabling sub-meter effective azimuth detail in fine modes over swaths up to 40 km, independent of weather or daylight conditions. Advanced Gaofen SAR variants, including Gaofen-12, incorporate hierarchical processing for resolutions as fine as 0.3 meters in selected modes, prioritizing coastal and urban feature discrimination. Onboard sensor technologies include integrated units for real-time compression, geometric correction, and radiometric adjustment, reducing downlink volume while preserving . calibration employs onboard lamps, sun diffusers, and vicarious methods validated against ground reference sites and ocean targets, achieving radiometric accuracy within 5% as demonstrated in cross-calibration with hyperspectral instruments. These hardware innovations enable Gaofen sensors to exceed the imaging quality of early international counterparts like SPOT-5 (2.5-5 meter panchromatic), providing finer detail through optimized detector arrays and .

Orbital Configurations and Coverage

The Gaofen constellation employs a diverse set of orbital configurations to balance high-resolution with persistent regional monitoring. Most optical and satellites operate in sun-synchronous low Earth orbits (LEO) at altitudes ranging from 500 to 700 km, with inclinations of 97° to 98° to ensure consistent solar illumination for imaging passes. For instance, Gaofen-1 orbits at 645 km with a 98° inclination, while Gaofen-2 follows a 631 km near-circular path at 97.7° inclination, and Gaofen-12 maintains a 630 km altitude at 98° inclination. These parameters optimize ground resolution by minimizing atmospheric and enabling swath widths suitable for broad-area surveys, with individual satellites achieving revisit cycles of up to 4 days. Complementing the LEO fleet, Gaofen-4 occupies a at approximately 35,786 km altitude over 106° E , facilitating continuous fixed-point observation over without the need for repeated passes. This GEO configuration supports sub-hourly imaging updates for targeted regions, contrasting with the polar-oriented coverage of inclined LEO orbits that prioritize global latitudinal sweeps from 80°N to 80°S. The constellation's deployment strategy leverages multiple satellites in phased SSO planes to enhance , reducing effective revisit times across the network. By the early , with over 25 Gaofen satellites launched, the system achieves sub-daily coverage over Chinese territory through coordinated passes, meeting CHEOS objectives for high-frequency national monitoring while extending to worldwide revisits of no more than 5 days in key areas. This multi-orbit approach ensures persistent observation capabilities, with LEO elements providing high-fidelity snapshots and GEO assets enabling real-time regional persistence.

Operational Applications

Civilian and Economic Uses

Gaofen satellites support agricultural monitoring through high-resolution multispectral imagery, enabling the derivation of vegetation indices like the (NDVI) for crop yield prediction. For instance, Gaofen-6 data has been used to estimate rice yields under varying wheat residue coverage levels, with optimal yields observed at 60-75% coverage, facilitating data-driven decisions in cultivation. Similarly, Gaofen-1 and Gaofen-2 imagery aids in crop planting area prediction and classification, integrating spectral features for accurate vegetation health assessment and yield analysis in regions like Yangling District. In , Gaofen satellites provide rapid mapping for flood monitoring, as demonstrated during the July 2020 floods in southern , where Gaofen-1, Gaofen-3, and Gaofen-6 captured 73 images by July 13 to observe high-risk areas and support relief efforts. Gaofen-3 further contributed continuous monitoring of flooded areas in , delivering real-time data for frontline disaster management. Urban planning benefits from Gaofen imagery in land surveys, road network design, and building extraction; Gaofen-11 and Gaofen-12 satellites, for example, enable high-precision mapping of urban structures from and data. Gaofen-7 datasets support automated building height estimation and extraction, essential for development and verification. Economic applications extend to the , where Gaofen-11 provides geographic data for infrastructure projects, including and route planning across participating countries. Environmental tracking via Gaofen-1 monitors aeolian dynamics, using time-series data fused with MODIS to map land distribution changes efficiently over large areas. These capabilities enhance , with agricultural applications promoting precision techniques that optimize inputs through yield forecasting, though quantified economic gains vary by implementation.

National Security and Dual-Use Roles

The Gaofen constellation operates under China's (MCF) strategy, which integrates civilian space assets into (PLA) operations for enhanced . This policy, formalized in 2017, mandates resource sharing between state-owned enterprises and military entities, enabling Gaofen satellites to provide high-resolution imagery for PLA , , and (ISR) tasks. Gaofen data supports real-time monitoring through the Aerospace Control Center (BACC), which manages both Gaofen and dedicated military series satellites for fused operational use. Gaofen satellites contribute to border surveillance and , particularly in contested areas like the . For instance, optical and (SAR) sensors on Gaofen-3 and Gaofen-11 enable persistent tracking of naval vessels and , with resolutions down to sub-meter levels for identifying military assets. These capabilities have been utilized for monitoring foreign military activities near disputed islands, integrating with PLA ground stations for rapid data dissemination to support anti-access/area-denial (A2/AD) strategies. High revisit rates from the constellation's configuration—up to daily coverage in key theaters—facilitate timely threat assessment without reliance on foreign systems. The dual-use nature of Gaofen's electro-optical (EO) and SAR payloads allows for precise target identification comparable to dedicated reconnaissance satellites, including potential applications in counterspace operations through orbital object tracking. Satellites like Gaofen-11, with panchromatic resolutions below 0.5 meters, provide imagery rivaling U.S. systems for discriminating space assets or ground-based threats. This fusion achieves technological independence by domesticating high-resolution , reducing vulnerabilities to export controls on sensitive components. However, data products from Gaofen remain tightly controlled, with commercial exports limited to aggregated or lower-resolution variants, prioritizing over international collaboration.

Achievements and Impacts

Technological Advancements

The Gaofen series has advanced resolutions from 2-meter panchromatic capabilities in Gaofen-1, launched on April 26, 2013, to sub-0.5-meter levels in satellites like Gaofen-11 by the early 2020s, enabling detailed Earth surface monitoring comparable to leading international systems. Gaofen-2, operational since August 19, 2014, improved to 0.8-meter panchromatic resolution with enhanced sensor design. In technology, Gaofen-3 has produced over 2.79 million images since its December 2016 launch, reflecting high-volume data acquisition and processing efficiency as of 2025. This output underscores improvements in C-band polarimetric SAR systems, supporting resolutions down to 1 meter in spotlight mode. Satellite agility has seen key innovations, including fast-roll mechanisms and high-precision attitude control in Gaofen-2's platform, facilitating rapid reorientation for multi-angle . Gaofen-9 introduced three-dimensional agile maneuvering, optimizing observation efficiency through enhanced freedom in pointing and tracking. Domestic sensor development has promoted technological , with indigenous components in Gaofen satellites achieving self-sufficiency in high-resolution data production and reducing reliance on imported technology, as evidenced by performance metrics matching global benchmarks.

Contributions to Global Monitoring

Gaofen satellites have supplied high-resolution imagery and data for international , including the February 2023 Turkey-Syria , where Gaofen-derived images enabled rapid assessment of damaged infrastructure and supported rescue prioritization in affected regions. Similarly, the Gaofen-3 satellite has delivered over 1,300 scenes of data for more than 600 operations worldwide since its 2016 launch, aiding in , , and mapping by providing all-weather, day-night penetration capabilities. These contributions, part of China's Civil High-Resolution System (CHEOS), facilitate real-time global monitoring, with Chinese satellites tracking over 30 major international natural disasters since 2018, such as Iranian and southern Asian typhoons, thereby shortening assessment-to-action timelines from days to hours through prompt data dissemination to affected nations and agencies. In , Gaofen-5's hyperspectral sensors have enhanced mineral resource identification, as demonstrated in uranium exploration mapping in , where full-spectrum data (covering 0.4-2.5 μm wavelengths) distinguished alteration zones with accuracies exceeding 85% via spectral unmixing techniques, offering methodologies applicable to global geological surveys beyond domestic use. For and weather policy, Gaofen series data integrate into models for detection, regional , and tracking; Gaofen-5's instruments, operational since 2018 and upgraded in 2022, monitor CO2 and concentrations, contributing to atmospheric composition datasets that refine international variation analyses and emission inventories. These applications support policy decisions in and disaster preparedness, with Gaofen imagery enabling precise land-use changes for economic sectors like and , though quantified global economic returns remain tied to national implementations rather than direct international attribution.

Criticisms and Geopolitical Implications

International Security Concerns

The , as part of China's High-Resolution System (CHEOS), has elicited concerns from U.S. policymakers regarding its dual-use contributions to (PLA) intelligence, , and reconnaissance (ISR) operations. The U.S.-China Economic and Security Review Commission (USCC) assesses that Gaofen satellites, including those in providing multispectral and , enable precise tracking of U.S. and allied military assets, such as naval vessels, thereby undermining operational secrecy and complicating command-and-control in potential conflicts. This persistent ISR capability supports PLA early warning, battlefield reconnaissance, and precision targeting, which could extend to anti-satellite (ASAT) operations by furnishing real-time data for kinetic or non-kinetic counterspace activities. Such advancements heighten risks of regional , as high-resolution monitoring allows to exert pressure on adversaries through demonstrated surveillance dominance without kinetic escalation. The scaling of Gaofen's high-resolution imaging—achieved via a growing constellation of over 470 ISR satellites—represents a proliferation of capabilities akin to U.S. systems like the KH-11 Keyhole series, but adapted for mass, all-weather surveillance that erodes prior space norms limiting such technology to select national actors. U.S. analyses highlight how this network, integrated with AI for target detection, challenges strategic stability by enabling the PLA to monitor and potentially disrupt U.S. space-dependent forces, including in scenarios involving or the . Proliferation risks are compounded by commercial offshoots, such as data from affiliated constellations sold internationally, including to entities like Russia's , prompting U.S. sanctions on involved firms. Chinese state sources maintain that Gaofen serves primarily civilian purposes, such as , , and , in line with commitments to the peaceful use of and opposition to its weaponization. has asserted sovereignty over its space program, arguing that Western critiques overlook comparable commercial high-resolution systems, like Maxar's satellites offering sub-meter imagery, while imposing export controls that perpetuate technological disparities. Nonetheless, the opaque integration of Gaofen data into PLA systems underscores ongoing dual-use tensions, with U.S. assessments prioritizing of military applications over official declarations of intent.

Technical and Reliability Issues

The Gaofen constellation has encountered several launch-related reliability challenges, primarily due to failures during deployment. In September 2016, a Long March 4C malfunctioned shortly after liftoff from the , preventing the Gaofen-10 satellite from reaching orbit; this marked one of the early setbacks for the program and required the subsequent deployment of a replacement, Gaofen-10R, in October 2019 to fulfill the mission's optical reconnaissance objectives. Similar issues have affected affiliated high-resolution payloads, such as the Jilin-1 in 2020, which failed to achieve its intended orbit following a solid-fuel anomaly, highlighting dependencies on domestic prone to occasional upper-stage separations or ignition failures. These incidents underscore the risks of relying on a concentrated set of launch sites, including , , and , where or weather-related delays can compound access bottlenecks. Data quality assessments reveal inconsistencies in radiometric and geometric performance across Gaofen sensors. U.S. Geological Survey characterizations of Gaofen-1 identified striping artifacts in wide-field-of-view (WFV) imagery and variations in modulation transfer function (MTF) that affect sharpness, necessitating post-processing corrections for precise applications like land cover mapping. For Gaofen-6, independent evaluations noted persistent quality issues, including unexplained artifacts in panchromatic and multispectral bands, alongside limited public data availability despite official claims of open access, which has constrained external validation efforts. While on-orbit calibrations mitigate some degradation—such as through lunar observations for Gaofen-4's panchromatic multispectral sensor—these findings indicate that advertised resolutions (e.g., 2 meters for Gaofen-1 WFV) require user-applied adjustments to achieve consistent accuracy, particularly in off-nadir views where view-angle effects degrade radiometric fidelity. To address single-point failures, the Gaofen architecture incorporates via multi-satellite constellations in sun-synchronous orbits, enabling coverage; for instance, Gaofen-6 supplements Gaofen-1's capabilities with identical WFV sensors for enhanced revisit rates. However, analyses of systems, including those from Chinese orbital dynamics studies, acknowledge inherent vulnerabilities to kinetic threats like anti-satellite intercepts, which could disrupt clustered formations without sufficient maneuvering reserves or diversified altitudes—prompting ongoing refinements in and attitude control for resilience. Empirical orbital data from tracking networks show stable post-deployment maneuvers for most Gaofen units, but unmitigated anomalies in isolated cases have led to minor altitude adjustments outside nominal parameters.

References

  1. https://spj.science.org/doi/10.34133/2022/9769536
  2. https://www.eoportal.org/satellite-missions/gaofen-1
  3. https://chinaspacereport.wordpress.com/spacecraft/gaofen/
  4. https://www.cnsa.gov.cn/english/n6465652/n6465653/c6768527/content.html
  5. https://www.eoportal.org/satellite-missions/gaofen-3
  6. https://en.most.gov.cn/pressroom/201607/t20160727_126827.htm
  7. https://pubs.usgs.gov/publication/ofr20211030M
  8. https://spacenews.com/china-launches-new-gaofen-14-stereo-mapping-satellite/
  9. https://www.space.com/china-launches-earth-observation-gaofen-satellites
  10. https://mezha.net/eng/bukvy/china-launches-gaofen-14-02-earth-observation-satellite-for-defense-and-economy/
  11. https://www.globalsecurity.org/space/world/china/cheos.htm
  12. https://www.geodoi.ac.cn/weben/Pdfdown.aspx?paperID=2cb8adf7-f969-430e-acbe-fb838771e323
  13. https://www.un-spider.org/news-and-events/news/china-launches-satellites-disaster-warning-and-emergency-response
  14. https://www.cnsa.gov.cn/english/n6465715/n6465716/c6840357/content.html
  15. https://www.uscc.gov/sites/default/files/2020-05/China_Space_and_Counterspace_Activities.pdf
  16. https://2017-2021.state.gov/military-civil-fusion/
  17. https://chargedaffairs.blog/2024/08/21/the-strategic-positions-behind-chinas-space-militarization/
  18. https://idstch.com/geopolitics/chinas-space-silk-road-strategy-elevating-its-global-space-power-status/
  19. https://news.cgtn.com/news/2019-12-15/Gaofen-satellites-upgrade-China-s-civilian-mapping-practice-Mrt66LeUUg/index.html
  20. https://www.unoosa.org/pdf/pres/stsc2014/tech-47E.pdf
  21. https://space.skyrocket.de/doc_sdat/gf-1.htm
  22. https://www.eoportal.org/satellite-missions/gaofen-2
  23. https://space.skyrocket.de/doc_sdat/gf-2.htm
  24. https://space.skyrocket.de/doc_sdat/gf-3.htm
  25. https://space.skyrocket.de/doc_sdat/gf-5.htm
  26. https://www.nasaspaceflight.com/2018/05/long-march-4c-lofts-gaofen-5/
  27. https://english.news.cn/20251026/ab7c5cf6d1ec4c0580e92c02baa475a5/c.html
  28. https://www.tandfonline.com/doi/full/10.1080/10095020.2020.1838957
  29. https://pubs.usgs.gov/of/2021/1030/b/ofr20211030b.pdf
  30. https://space.skyrocket.de/doc_sdat/gf-4.htm
  31. https://innoter.com/en/satellites/gaofen-4-gf-4/
  32. https://pubs.usgs.gov/of/2021/1030/m/ofr20211030m.pdf
  33. https://isprs-annals.copernicus.org/articles/V-1-2022/145/2022/
  34. https://www.nik.com.tr/content_sistem_uydu.asp?id=93&language=english
  35. https://spacenews.com/china-launches-gaofen-3-high-resolution-radar-imaging-satellite/
  36. https://www.tandfonline.com/doi/full/10.1080/10095020.2022.2124129
  37. https://ieeexplore.ieee.org/document/11006049/
  38. https://ieeexplore.ieee.org/document/10930789/
  39. https://www.mdpi.com/1424-8220/25/15/4616
  40. https://www.nature.com/articles/s41377-020-0306-z
  41. https://iopscience.iop.org/article/10.1088/1755-1315/509/1/012033
  42. https://www.sciencedirect.com/science/article/pii/S1569843222001625
  43. https://www.mdpi.com/2072-4292/12/23/3990
  44. https://ieeexplore.ieee.org/document/8127395/
  45. https://spaceflightnow.com/2015/12/29/china-launches-eagle-eyed-satellite-to-stare-down-at-earth/
  46. https://www.csis.org/analysis/no-place-hide-look-chinas-geosynchronous-surveillance-capabilities
  47. https://www.chinadaily.com.cn/a/202401/24/WS65b063dfa3105f21a507df95.html
  48. https://ieeexplore.ieee.org/document/8899816/
  49. https://www.mdpi.com/2072-4292/12/6/1037
  50. https://spacenews.com/china-launches-new-gaofen-12-remote-sensing-satellite/
  51. https://www.cnsa.gov.cn/english/n6465652/n6465653/c6480538/content.html
  52. https://space.oscar.wmo.int/satellites/view/gf_4
  53. https://www.thespacereview.com/article/4453/1
  54. https://www.researchgate.net/publication/360678005_CHINA%27S_HIGH-RESOLUTION_EARTH_OBSERVATION_SYSTEM_CHEOS_ADVANCES_AND_PERSPECTIVES
  55. https://www.isprs-annals.copernicus.org/articles/V-3-2022/583/2022/isprs-annals-V-3-2022-583-2022.pdf
  56. https://www.agroengineering.org/jae/article/view/1698
  57. https://www.mdpi.com/2072-4292/15/15/3792
  58. http://english.scio.gov.cn/m/chinaprojects/2020-07/17/content_76281452.htm
  59. https://spaceflightnow.com/2019/11/28/china-launches-radar-observation-satellite/
  60. https://www.nature.com/articles/s41597-024-03009-5
  61. https://www.deccanchronicle.com/world/asia/310718/china-launches-earth-observation-satellite-to-monitor-belt-and-road-in.html
  62. https://pmc.ncbi.nlm.nih.gov/articles/PMC5177959/
  63. https://www.researchgate.net/publication/392952366_Estimating_rice_yield_under_different_wheat_residue_coverage_levels_using_multispectral_Gaofen_satellite_data_and_remote_sensing_indices
  64. https://www.isdp.eu/wp-content/uploads/2025/07/files_chinas-military-civil-fusion-in-space-strategic-transformations-and-implications-for-europe.pdf
  65. https://media.defense.gov/2021/nov/03/2002885874/-1/-1/0/2021-cmpr-final.pdf
  66. https://imrmedia.in/chinas-dual-use-space-support-programme/
  67. https://www.uscc.gov/sites/default/files/2024-12/Chinas_Remote_Sensing.pdf
  68. https://imrmedia.in/chinas-fleet-of-military-satellites/
  69. https://ordersandobservations.substack.com/p/the-plas-imagery-satellites
  70. https://spacenews.com/china-launches-new-gaofen-11-high-resolution-spy-satellite-to-match-u-s-capabilities/
  71. https://www.mdpi.com/2072-4292/15/10/2512
  72. http://english.cas.cn/newsroom/archive/china_archive/cn2015/201512/t20151230_158257.shtml
  73. https://news.cgtn.com/news/2023-02-19/Chinese-scientists-deploy-satellites-for-Turkish-earthquake-relief-1hxO4tTRwOY/index.html
  74. https://www.nationthailand.com/international/30373831
  75. https://www.researchgate.net/publication/355404561_Application_of_Gaofen-5_Hyperspectral_Data_in_Uranium_Exploration_A_Case_Study_of_Weijing_in_Inner_Mongolia_China
  76. https://www.spacedaily.com/reports/CNSA_announces_full_operation_of_Gaofen_5_01A_boosting_environmental_and_climate_monitoring_999.html
  77. https://www.mdpi.com/2072-4292/15/4/1105
  78. https://www.nasaspaceflight.com/2016/09/long-march-4c-apparently-fails-during-gaofen-10-launch/
  79. https://www.seradata.com/gaofen-10r-satellite-is-launched-by-china-to-replace-destroyed-predecessor/
  80. https://www.airport-technology.com/news/china-jilin-1-gaofen-02c/
  81. https://pubs.usgs.gov/publication/ofr20211030B
  82. https://www.researchgate.net/publication/380333763_Using_the_Moon_for_on-orbit_absolute_radiometric_calibration_of_GaoFen-4_PMS
  83. https://www.dia.mil/Portals/110/Documents/News/Military_Power_Publications/Challenges_Security_Space_2022.pdf
Add your contribution
Related Hubs
User Avatar
No comments yet.