Here is the conclusion of Henri K
Conclusion
China has a triple radar, optical and electronic capability for detecting, identifying and tracking ships at sea.
Even without taking into account the real-time tracking capability from the geostationary orbit, the large optical constellation Field JB9 and the constellations SAR JB-5 and JB-7 make it possible to sweep every day a wide area to find contacts of interest, and have a good chance to refresh the tracks of the most interesting contacts every few Hours, even for vessels without electromagnetic emissions. As a result, it seems unlikely that an enemy naval group will hide long in the ocean.
However, in the event of heavy cloud cover, only SAR satellites can be used, which can severely limit the system's ability to identify and track. This does not mean that China would blind other means of detection, as
, or just its
may complement the satellite system, thus seriously question invulnerability The intervention of the United States to intervene in a new crisis of Taiwan would be much more risky, and so much less likely.
The Indian did some simulation study on the effectiveness of Chinese space surveillance system
China’s Constellation of Yaogan Satellites & the ASBM
Authors: S. Chandrashekar and Soma Perumal
To read the complete report in pdf click
With the recent launch of the Yaogan 19 satellite China has in place an advanced space capability to identify, locate and track an Aircraft Carrier Group (ACG) on the high seas. This space capability is an important component of an Anti-Ship Ballistic Missile (ASBM) System that China has set up.
The current 19 satellite constellation consists of ELINT satellites, satellites carrying Synthetic Aperture Radar (SAR) sensors as well as satellites carrying optical imaging sensors. Based on the orbit characteristics, their local time of equatorial crossing and other related parameters, these satellites can be grouped into different categories that perform the various functions for identifying, locating and tracking the ACG.
Yaogan 9 (Yaogan 9A, 9B, 9C), Yaogan (16A, 16B, 16C) and Yaogan 17 (17A, 17B, 17C) are the three clusters that are equipped with ELINT sensors that provide broad area surveillance over the Oceans. With a coverage radius of about 3500 Km, they provide the first coarse fix for identifying and locating an ACG in the Pacific Ocean.
Yaogan 13, Yaogan 10, Yaogan 18 and Yaogan 14 are the satellites carrying a SAR sensor. With Local times of crossing of 02 00, 06 00, 10 00 and 14 00 hours and a resolution of 1 to 3 m , they provide all weather as well as day and night imaging capabilities over the regions of interest.
Yaogan 11, Yaogan 4, Yaogan 2 and Yaogan 7 constitute the high resolution optical satellites in the current constellation. The sensors they carry may have resolutions of between 1 to 3 m. Their local times of crossing of 09 00, 11 00, 13 30, and 15 00 hours respectively ensure favourable illumination conditions for their imaging missions. Yaogan 19 and Yaogan 15 satellites with local times of crossing of 10 30 and 14 30 hours respectively are optical imaging satellites with medium resolution (5 to 10 m) capabilities. They act as a broad area coverage complement for the SAR as well as the high resolution optical imaging satellites.
The Yaogan 12 which replaced the Yaogan5 has the orbital characteristics of a SAR mission but its local time of crossing is 10 30 AM. This is very close to the 10 00 hours crossing time of the Yaogan 18 SAR satellite. Having two satellites spaced so close to each other makes it unlikely that it is a SAR mission. Most probably this is a high resolution optical imaging satellite that complements the broad area coverage provided by the 1200 km orbit of the Yaogan 15 and Yaogan 19 satellites.
Using typical sensor geometries and the two line orbital elements available from public sources the ability of the current constellation to identify, locate and track the Aircraft Carrier Group was simulated.
The three ELINT clusters typically make 18 contacts in a day with the moving target. The maximum period for which the target remains outside the reach of the ELINT satellites is about 90 minutes in a day. The SAR and the optical imaging satellites together typically provide 24 satellite passes over the target. About 16 targeting opportunities, during which the uncertainty in the target’s location is less than 10 km, are available in a day.
The analysis and the simulation results suggest that China has in place an operational ASBM system that can identify, locate, track and destroy an Aircraft Carrier in the Pacific Ocean. This seems to be an important component of a larger Chinese Access and Area Denial Strategy focused around a conflict over Taiwan.
