2.1 Meteorological Satellites
The Chinese meteorological satellite program, FengYun (FY), was initiated in the 1960s and is composed of both polar-orbiting (odd numbered) and geostationary (even numbered) satellites. Each satellite is assigned an incremental alphabetic suffix according to its launch sequence.
The NSMC operates both the polar-orbiting and geostationary components, but the development and implementation of the FY program—from satellite development, launcher design, and manufacture, to telemetry, control, and ground applications—is the result of joint efforts between many institutes in China. The FY program is designed to enhance China’s three-dimensional atmospheric sounding and global data acquisition capabilities, in an effort to collect more cloud and surface characteristics data from which meteorologists may infer atmospheric, land surface, and sea surface parameters that are global, all-weather, three-dimensional, quantitative, and multispectral.
FY-1 was China’s first generation of sun-synchronous orbiting meteorological satellites. FY-1A and FY-1B were experimental satellites, launched on July 9, 1988 and September 3, 1990, respectively. FY-1C and FY-1D (operational satellites) were subsequently launched on May 10, 1999 and May 15, 2002. To date, all FY-1 satellites have completed their missions. The FY-1 series carried the visible and Infrared radiometer (VIRR) and space environment monitor (SEM). VIRR provided Earth imaging capability with ten channels at 1.1 km nadir spatial resolution, while SEM observed energetic particles in solar winds.
China started to develop its geostationary meteorological satellites, named FY-2, in the 1980s. The first satellite, the experimental FY-2A, was launched on June 10, 1997 and positioned at 105°E above the equator. This was followed by another experimental satellite, FY-2B. The subsequent FY-2C, FY-2D, and FY-2E satellites had noticeably enhanced performance; for example, the onboard scanning radiometer had five channels rather than the three of its predecessors. The latest satellites in the series, FY-2F, FY-2G, and FY-2H, are designed to serve as a consistent and stable bridge to the second generation of Chinese geostationary meteorological satellites, as the first generation fleet approaches the end of its life in the 2015 timeframe.
The FY-2 series is equipped with a stretched visible and infrared spin scan radiometer (S-VISSR) that scans the full Earth disk every 30 min at a spatial resolution of around 5.0 km (IR) and 1.25 km (VIS). The satellites are also equipped with SEMs to monitor the space environment where the satellites operate.
China’s second-generation polar-orbiting meteorological satellite series, FY-3, began with the launch of the experimental FY-3A and FY-3B satellites on May 27, 2008 and November 5, 2010, respectively. The operational FY-3C satellite, with 11 instruments and enhanced remote sensing capabilities, was launched on September 23, 2013. The FY-3 program has a life expectancy of 15 years.
FY-4 is China’s second-generation geostationary meteorological satellite series. These new generation satellites are designed with enhanced imagery scanning capabilities, desirable for monitoring small- and medium-scale weather systems. FY-4 satellites are also equipped with vertical atmospheric sounding and microwave detection capabilities to address 3D remote sensing at high altitudes. They are also able to make solar observations of extreme ultraviolet and X-ray emissions, in a bid to enhance China’s space weather watch and warning capability. FY-4 satellites will come in two varieties, carrying either optical or microwave instruments. An optical satellite will carry a ten-channel 2D scanning imager, an interferometric vertical detector, a lightning imager, CCD camera, and an Earth radiation budget instrument. The satellites will produce full-disk earth images every 15 min.
2.2 Oceanic Satellites
The Chinese oceanic satellite program, HaiYang (HY), has been designed to detect ocean color and to support ocean bio-resource utilization, ocean pollutant monitoring and prevention, offshore resource exploration, and marine science. Eight oceanic satellites will be launched before 2020, including four ocean color satellites, two dynamic ocean environment satellites, and two ocean radar satellites.
HY-1 series satellites carry an ocean color scanner and coastal zone imager to measure global ocean color, temperature, and coastal zone dynamic change. HY-1A was an experimental mission launched on May 15, 2002 and equipped with a ten-channel ocean color scanner (3-day revisit frequency, 1.1 km nadir spatial resolution) and a four-band CCD (7-day revisit frequency, 250 m nadir spatial resolution). The follow-up satellite, HY-1B, was launched on April 11, 2007.
HY-2 series satellites measure marine environment dynamics and are used for all-weather assessments of offshore and global sea surface wind fields, sea surface height, significant wave heights, and sea surface temperature. Remote sensing payloads include a microwave scatterometer, radar altimeter, scanning microwave radiometer, and calibration microwave radiometer. The first HY-2A satellite was launched on August 16, 2011.
HY-3 will be an ocean radar satellite series used to detect ocean waves, ocean ice, and oil leaks, among other features.
2.3 Earth Resources Satellites
CBERS, also known as ZiYuan-1 (ZY-1), is a joint program between China and Brazil that was initiated in the 1980s. The CBERS program was designed to meet the needs of both countries and to allow them to enter the emerging market of satellite imagery. Despite an initial commitment to just two satellites, a series of missions have now been jointly built by China and Brazil. Following CBERS-1 and -2, both governments decided to expand the cooperation to include CBERS-2B, -3 and -4.
ZY-1-02C was the third satellite in the CBERS-2 series, but it was developed exclusively as a Chinese project with no Brazilian participation. It was the first high-resolution Chinese imaging mission. ZY-1-02C launched on December 22, 2011. CBERS-3 was launched on December 9, 2013 but unfortunately failed to reach its orbit. CBERS-4 was successfully launched on December 7, 2014. It will be followed by further joint China–Brazil missions.
2.4 China High-Resolution Earth Observation System
The China High-resolution Earth Observation System (CHEOS), also known as GaoFen (GF), is one of 16 tasks that are listed in the National Medium- and Long-term Plan for Science and Technology Development (2006–2020). The program was proposed in 2006 and approved and initiated in 2010. CHEOS is a series of small satellites for high-resolution land observation being developed between 2010 and 2020. The entire GF series of satellites will be in orbit by 2020, mostly sun synchronous around 10:30 or 06:00 except for GF-4, which will be placed into geostationary orbit. The design lifetimes are 5 years for GF-1/2 and 8 years for GF-3/4/5. China plans to launch six GF satellites between 2013 and 2016. The main goal of the GF series is to provide near-real-time observations for disaster prevention and relief, climate change monitoring, geographical mapping, environment and resource surveying, and precision agriculture.
2.5 Environmental Protection and Disaster Monitoring Constellation
The Environmental Protection and Disaster Monitoring Constellation mini-satellite constellation, also known as HuanJing-1 (HJ-1), is a national program to construct a network of Earth observation satellites. The overall objective is to establish an operational Earth-observing system for disaster monitoring and mitigation using remote sensing technology in order to improve the efficiency of disaster mitigation and relief.
The HJ-1 constellation is comprised of three mini-satellites, referred to as the ‘2 + 1 constellation’. HJ-1A and HJ-1B were launched together on September 6, 2008. HJ-1A was equipped with two optical wide view CCD cameras (WVC) and one hyperspectral imager (HSI). Both WVCs take images with four bands at 30 m spatial resolution with a swath width of 700 km. HSI measures 110–128 bands at 100 m spatial resolution with a swath of 50 km. Likewise, HJ-1B was equipped with two optical WVCs as well as one infrared multispectral scanner (IRMSS). HJ-1C was launched on November 19, 2012, equipped with an S-band synthetic aperture radar (SAR) payload.
2.6 The Private Sector
Twenty-First Century Aerospace Technology is a private company that has received scientific funding support primarily from the Ministry of Science and Technology of China. The company operates Beijing-1 and Beijing-2, a constellation of three small Disaster Monitoring Constellation (DMC) satellites. Beijing-1 was equipped with a 4-m panchromatic camera and a 32-m multispectral camera with a swath of 600 km. The camera, developed by Surrey Satellite Technology Ltd. (SSTL, UK), had a design lifetime of 5 years. Beijing-1 was launched on October 27, 2005. This was followed up with the launch of three Beijing-2 DMC satellites on July 11, 2015, each carrying a 1-m panchromatic camera and a 4-m multispectral camera.
The Jilin-1 series is privately owned and operated by Chang Guang Satellite Technology Co., Ltd. The series includes one optical satellite, two video satellites, and one experimental satellite. The first satellite in the series, Jilin-1A, was launched in October 2015. By 2030, it will be joined by a further 137 satellites, forming a large constellation. Jilin-1A is capable of 0.72-m panchromatic/2.88-m multispectral imaging as well as 1.12-m spatial resolution video capture.
Beijing-1/2 and Jilin-1 are market-oriented satellite programs that aim to promote the commercial service of remote sensing technology in China.