China and Imagery Intelligence
On November 26, 1975, China's first "Squadron" returning remote sensing satellite was launched into space, accurately flying in space for 47 laps. The recovery cabin was safely landed in the Liuzhi area of ??Guizhou on November 29 according to ground instructions, marking China becoming the world. The third country to master satellite recycling technology. The satellite return capsule was donated by the Technical Department of the Seven Machines Department. It is now in the Chinese People's Revolutionary Military Museum.
The reconnaissance satellite represented by the "Squadron" series has been developed to the fourth generation, effectively safeguarding the PLA's maintenance of sovereign operations. "Jianbing No.1" (FSW-0) is the first type of returning satellite developed by China. It uses a prism scanning panoramic camera to obtain the first batch of photographic photos, but the resolution is low and the distortion is serious. The satellite adopts the analog three-axis stability control system, but there is no track control system, so the track attenuation is faster, the time of the track is short, and the accuracy of the return point is also affected. This return-type satellite used to be China's most important survey and remote sensing satellite. Since the 1970s, it has developed six models and carried out 24 launches.
November 4, 1996 is another memorable day in the history of China's aerospace. China's second-generation return-type photo census satellite, "Jianbing No.1" (FSW-2-3), after 15 days of orbital operation, is scheduled. It landed safely in the central part of Sichuan, bringing back a film with a ground resolution of 2.5 meters, which is three times higher than the resolution of the first generation of Jianbing No.1. "Feibing No.4" (FSW-3) is also China's second-generation return-type photographic mapping satellite. At 18 days of orbital time, the positioning accuracy of the fixed target on the ground is more than ten meters, which satisfies the requirements of the second-generation strategic missile target positioning accuracy. China's second generation of strategic weapons (DF-5B, DF-31A, DH-10) systems form practical capabilities.
The rise of the third generation of transmission satellites elevated China's military reconnaissance capabilities to a high level of technology. Photoelectric imaging data transmission type remote sensing satellite can significantly improve the real-time intelligence and extend the working life of the satellite. The "Zhibing No.3" (ZY-2) photoelectric imaging data transmission satellite has a life span of two years and a ground resolution of 3 to 1.5 meters. "Yingbing No.6" (YG-2) has a ground resolution of one meter and a computer enhanced processing image with a ground resolution of 0.6 meters.
At present, China's most advanced reconnaissance satellite is a radar imaging reconnaissance satellite, which uses synthetic aperture radar technology to detect all-weather and all-day real-time reconnaissance, and can detect targets under superficial groundwater. Compared with optical imaging satellites, the superiority is obvious. . The "Jianbing No. 5" (YG-1) Synthetic Aperture Radar Reconnaissance Satellite was launched in April 2006 with a ground resolution of 5 meters. The "Yi-3" (YG-3) synthetic aperture radar reconnaissance satellite was launched in November 2007. The rate has been improved.
China operates three different space based reconaissance systems under the Yaogan Weixing [Remote Sensing Satellite] nomenclature. The first to be launched [in 2005] carried a synnthetic aperture radar, the second version carries an electro-optical camera, and the third version consists of a triplet of spacecraft for passive electronic ocean surveillance. Space-based imagery supports the full range of military intelligence activities including indications and warning, current intelligence, order of battle, scientific and technical intelligence assessments, targeting, and combat assessments. Imagery is also used to conduct mission planning and rehearsal.
These spacecraft also have a Jianbing military designation. The term Jian, meaning build; construct; erect, or establish; set up; found [or less probably health], is commonly used with Chinese spacecraft. "Jian bing" is literally Soldiers Building, or more readily, "military spacecraft". There is the usual confusion common to Chineses programs, and classified intelligence programs, as to the precise allocation of these designators. Richard D. Fisher, in his 2008 China's Military Modernization: Building for Regional and Global Reach states that "The PLA also developed digital electro-optical satellites, the JianBing-6 and JianBing-8, which will complement the JianBing-5 and -7 radarsats". while other sources reverse the allocation of the 7 and 8.
The interpretation of "jian bing" in English can "point soldier" or "sharp soldier". This is a scout, a vanguard, a patrol or a package that specifically spies on the inside of the opponent's team, but in the eyes of military personnel, there is only one interpretation of this word, that is sharp soldiers. Because of cultural factors, living conditions are more primitive, the psychological self-construction of the members and the determination of the will, and the sense of honor and responsibility given by the tradition.
Jianbing is also a traditional dish often eaten for breakfast. Jianbing is a fried crepe made from a batter of wheat flour and coarse grains (beans, cereals, etc.) fried on a griddle with an egg and topped with scallions, baocui (a crispy fried cracker) and cilantro. It can be thick, thin, crispy or chewy, but itís almost always folded several times before serving. According to tradition, jianbing was invented during the Three Kingdoms period (220-280) when Zhuge Liang, Liu Beiís chancellor in Shandong Province, faced with feeding an army of soldiers who had lost their woks. Zhuge Liang ordered the cooks to mix water with wheat flour and spread the dough on to copper-made griddles suspended over fires. The dish lifted his soldiersí morale and they fought their way out of an ambush. Today, Jianbing is found on nearly every street corner, especially outside of subway stations or tourist attractions.
Some sources report that the developer of the JB-10 Yaogan Radar Satellite was CAST (502th institute), while other sources report the developer as SAST. It is generally believed that the two institutes are responsible for the radar and EO spacecraft, though evidently there is confusion as to which is which. It is also reported that all these satellites were designed by the China Aerospace Science and Technology Corpís (CASC) No5 Research Institute and No8 Research Institute, with final fabrication and systems integration taking place at the CASCís Shanghai Academy of Spaceflight Technology.
The PRC has been conducting space-based imaging of the Earth since 1975, when it became the third country in the world to retrieve high resolution photographs of the planet shot from space. Although some of these FSW (Fanhui Shi Weixing - Recoverable Satellite) missions may have been in whole or in part related to civil requirements, Western assessments have long held that some, if not all, were also concerned with photographic reconnaissance of a national security nature. By mid-1999 a total of 17 FSW-class spacecraft had been orbited with 15 successful recoveries, and there were no subsequent flights.
The Satellite Area Monitoring System had been developed gradually based on self-reliance Information, derived from tens of thousand surface features films taken by recoverable remote sensing satellites and earth surface data obtained by other satellites after processing, cannot be or is difficult to be obtained by other means. The information had provided an important basis for China's land planning and macro-economic decision, and played an important role in the modernization of national defense.
The onboard space optical remote sensors developed by China in the 20th century consist of the film visible camera, the transmission visible-infrared multispectal scanner and CCD camera. The multispectal scanners used for meteorological satellites are developed by Shanghai Institute for Technological Physics and other remote sensors are developed by Beijing Institute of Space Mechanics and Electricity.
The film visible camera is the main payload of the recoverable remote sensing satellite. China has successfully developed the FSW-0 prism scanning panoramic camera, the FSW-1 frame camera, the FSW-2 nodal panoramic camera and three kinds of star cameras. The focal length and size of the FSW-1 frame camera are comparable to those of space shuttle orbiter. The main performances of the FSW-2 nodal panoramic camera have reached the level of the same kinds of products of other countries.
China further improved the standards of its space cameras through the development of three models of such cameras. In the production of space-to-ground cameras, for instance, China reached a high standard through the development of prismatic scanner panoramic cameras, frame-type measuring cameras and "nodal" panoramic cameras.
For any country, the true reconnaissance capability of its existing reconnaissance satellites is top secret and is never made known to the public. China is no exception. The outside world knows precious little about the resolution power of China's reconnaissance satellites.
The stellar cameras on China's reconnaissance satellites are used for the precision measurement of the position of satellites and ground targets. At first China's stellar cameras are only capable of taking photos of fourth magnitude stars. Now they can take photos of stars up to the seventh magnitude. The number of stars photographed has also been increased from about ten to nearly 200. This is a big improvement. It shows in a way that China's aerophotographic technology has reached higher standards and that China is now able to accurately locate any spot on earth and therefore provide target indicators for strategic weapons.
China's Academy of Space Technology (CAST) engineers have conducted design work on a tactical imagery system and associated mobile ground receiving stations. The system is based on small satellite technology, uses a charged coupled device (CCD) array, and, when operating in a 700-kilometer sun synchronous orbit, is designed to have a five meter resolution.
In the next decade [ie, through 2020], even as Beijing fields a larger and more capable array of reconnaissance satellites, it probably will continue to employ commercial satellite imagery to supplement its coverage. China currently accesses high-resolution, commercial electro-optical, and synthetic aperture radar imagery from all the major providers including Spot Image (Europe), Infoterra (Europe), MDA (Canada), Antrix (India), GeoEye (United States), and Digital Globe (United States). Recently, China attempted to acquire a fully functional, European imaging satellite constellation, but was blocked by USML re-export laws due to U.S. technology being on the satellites. As part of the Administration's recommendations in this report, this technology would remain subject to the USML.
The Mean Local Time of the Ascending Node (MLTAN) of an orbit is defined as the angle between the orbit's ascending node and the mean Sun. The MLTAN is often presented in units of time with 12:00 PM - or noon - describing a Sun-synchronous orbit that places the Sun directly at zenith when the spacecraft is at the ascending node. The Mean Local Time of the Ascending Node (MLTAN) is one of the parameters used to describe the orbits of members of the constellation is . Satellites flying in constellations usually have a small range of MLTAN that they are allowed to fly in. Each spacecraft in the constellation is required to maintain a specific MLTAN range to avoid potential conjunctions with other constellation constituents.
Due to orbital perturbations, the MLTAN will drift requiring periodic correction. Orbital perturbation caused by the Sun and the Moon will cause the actual MLTAN of a spacecraft to deviate from a fixed value. Because of this, Inclination Adjustment Maneuvers (IAM) are required to counteract the luni-solar precession that perturbs pure sun-synchronous flying.Since the MLTAN drift rate is caused primarily by the J2 perturbation to the Earth's gravity and this perturbation is a function of orbital inclination, the MLTAN rate is controlled through inclination maneuvers. In order to maintain the relative geometry between the constellation members, inclination maneuvers are performed on all spacecraft in the constellation at approximately the same time. A Sun-synchronous orbit is designed to maintain a constant MLTAN by matching the J2 nodal rate of the satellite with the nodal rate of the mean Sun.
Right Ascension of the Ascending Node (RAAN) is an angle, measured at the center of the earth, from the vernal equinox to the ascending node. Satellites in a constellation typicaly have nearly identical orbital period and other elements, except for the Right Ascension of Ascending Node (RAAN), which are equally spaced at the equatorial plane. The real world is a bit more complicated.
|Join the GlobalSecurity.org mailing list|