China's Deep Space Network

[Martian2]

China's Deep Space Network

The Chinese VLBI (ie. Very Long Baseline Interferometry) Network consists of four massive radio telescopes, local atomic clocks, and computer processing of the radio interferometric signals.

The Chinese VLBI Network (CVN) spans the entire continental landmass of China. At the northeastern corner, there is a radio telescope in Beijing. On the eastern seaboard, there is another radio telescope located at Shanghai. In the south, there is a radio telescope in Kunming. To the northwest, the last radio telescope is in Urumqi (Xinjiang). Together, China has a "virtual"/interferometric telescope that is the size of continental China.

The good news is that if China decides to build a massive radio telescope on one of the South China Sea islands, it can create an interferometric telescope that is the size of East Asia.

As shown in the first citation below, China used its CVN to communicate and send commands to the Change'e I and II satellites in 2007 and 2010 respectively.

Also, Shanghai has upgraded its radio telescope and built a truly massive 65m (or 200 feet) steerable radio telescope. It is one of the largest steerable radio telescopes in the world. The Chinese VLBI Network is undergoing an upgrade as China pushes further into deep space.

EAVN/APT | About CVN

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Very Long Baseline Interferometry (VLBI)

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Tianma Telescope (Shanghai 65m Radio Telescope) | Shanghai Astronomical Observatory

 

[Keel]

It says "The Beijing and Urumqi station is a member of European ELBNI Network (EVN) and both stations play a role as longest baseline station"
So I guess we are also assisting the ESA in their deep space tracking too

Again, there is something to learn from the post
Keep up with your contribution to our knowlege and to our short-handed Chinese Community here @Martian2

Best wishes

 

[Keel]

More information to add:
Introduction to the EVN

The European VLBI Network (EVN) is an interferometric array of radio telescopes spread throughout Europe (and beyond) that conducts unique, high resolution, radio astronomical observations of cosmic radio sources. It is the most sensitive VLBI array in the world, thanks to the collection of extremely large telescopes that contribute to the network. The three stations from the Russian VLBI Network KVASAR (Svetloe, Zelenchukskaya, and Badary) joined the EVN as member stations in November 2009. The Korean VLBI Network (Yonsei, Ulsan, Tamna) became an Associate Member of the EVN in January 2014.

The map at left shows EVN and other participating stations, color-coded via:

• Yellow/Red: current operational EVN stations
• Cyan/Red: existing telescopes soon to be EVN stations
• Cyan/Blue: new EVN stations under construction
• Pink/Purple: non-EVN stations that have participated in EVN observations
• Green/Brown: non-EVN stations with whom initial EVN tests have been carried out

EVN Consortium board of directors
The general policy of the EVN is set by the EVN Consortium Board of Directors (CBD). Members of this board are the directors of the individual EVN member institutes. The board meets in the spring and autumn of each year.

Members of the board include:
EVN Consortium board of directors

• Anton Zensus (Chair) (MPIfR, DE)
• Rene Vermeulen (Vice-chair) (WSRT/ASTRON, NL)
• Rafael Bachiller (IGN, ES)
• Fernando Camilo (NAIC, USA)
• Ludwig Combrinck (HRAO, ZA)
• John Conway (OSO, SE)
• Luigina Feretti (IRA, IT)
• Simon Garrington (MERLIN/JBO, UK)
• Hong Xiaoyu (SHAO, CN)
• Alexander Ipatov (IAA, RU)
• Huib van Langevelde (JIVE, NL)
• Andrzej Marecki (TCfA, PL)
• Torben Schueler (BKG, DE)
• Bong-Won Sohn (KVN, KR)
• Joni Tammi (MRO/Aalto Univ., FI)
• Wang Na (XAO, CN)

Very-long-baseline interferometry
Very-long-baseline interferometry - Wikipedia, the free encyclopedia

Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy. In VLBI a signal from anastronomical radio source, such as a quasar, is collected at multiple radio telescopes on Earth. The distance between the radio telescopes is then calculated using the time difference between the arrivals of the radio signal at different telescopes. This allows observations of an object that are made simultaneously by many radio telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.

Interesting subject and that briefly explains why we need an atomic clock and a spread of telescope as widely as possible for optimal accuracy and coverage

and please read-on by clicking the wikipedia link above



Now the Chinese contribution:

1. NAOC Observing Facilities Distribution

2. Atomic clock

Chinese atomic clock given international recognition - Global Times
Source:Xinhua Published: 2014-8-21 22:50:59

A Chinese atomic clock has been accepted by international authorities as a primary basis for high-precision international atomic time, announced the National Institute of Metrology (NIM) on Thursday.

The cesium atomic clock, known as NIM-5 and developed by the institute, is a kind of extremely accurate time-keeping device. It can be accurate to within one second over 20 million years, according to Chinese media.

The nod from the Paris-based Bureau International des Poids et Mesures, the authority for international time and frequency standards, has made China the eighth country to calibrate the international atomic time, after France, the United States, Germany, Italy, Japan, the UK and Russia.

Insiders said the clock could define a Chinese atomic time independent from GPS signals or other international time-keeping data.




3. Some of the principal Chinese Radio Telescopes at different locations used to track Chinese and International space missions

Beijing

Urumqi



Shanghai

Yunnan





An illustration showing how Chang'e Lunar missions were tracked

为嫦娥发射准备?滇“探月望远镜”启用--科技--人民网

 

[TaiShang]

Again, there is something to learn from the post
Keep up with your contribution to our knowlege and to our short-handed Chinese Community here @Martian2

I second that!

Learning a lot from @Martian2 .

 

[GR!FF!N]

one question,with which countries,China made co-op on operating this DSN,as you know,to properly track spaceship/deep space missions constantly,one generally needs tracking stations across the globe..

Nasa's DSN has 3 ground stations

ESA too has widespread networks...

these are the most advanced.Russia has 3 ground stations,1 in Ukrain,2 in Russia.

ISRO too has a large network and it is expanding...

plus,ISRO use ships to track,as well as we had co-op with ISRO and SANSA to track some non visible portions of our Mars mission.

how China handles it??co-op with Russia perhaps??

 

[Martian2]

one question,with which countries,China made co-op on operating this DSN,as you know,to properly track spaceship/deep space missions constantly,one generally needs tracking stations across the globe..

Nasa's DSN has 3 ground stations

ESA too has widespread networks...

these are the most advanced.Russia has 3 ground stations,1 in Ukrain,2 in Russia.

ISRO too has a large network and it is expanding...

plus,ISRO use ships to track,as well as we had co-op with ISRO and SANSA to track some non visible portions of our Mars mission.

how China handles it??co-op with Russia perhaps??

China's Yuanwang ships are mobile tracking stations with large radio telescopes

China has a total of 6 Yuanwang space tracking ships. For manned spaceflights, China deploys at least four Yuanwang ships. For unmanned space programs like Chang'e II, China deploys only three Yuanwang ships.

By using interferometry, the three on-board Yuanwang radio telescopes act as a single massive unit that runs the length of the ship.
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Yuan Wang class tracking ship - Wikipedia, the free encyclopedia

"Another two Yuanwang-class vessels were launched in Shanghai in early 2007.[1]

Pictures of Yuanwang 6 were published as it has been revealed that both Yuanwang 5 and the newly commissioned ship would be on duty for the Shenzhou 7 mission.[2]

During the Shenzhou spacecraft flights, the four ships are positioned with:[3]

* Yuanwang 1 in the Yellow Sea
* Yuanwang 2 about 1500 km (about 900 statute miles) southwest of French Polynesia
* Yuanwang 3 off the Namibian coast
* Yuanwang 4 off the coast of Western Australia in the Indian Ocean
...
References

1. "Yuanwang Space Tracking Ships". [1]. June 3, 2007. Archived from the original on July 7, 2007. Retrieved July 12, 2007.
2. "远望六号航天测量船交付将执行神七任务". 人 民 网. April 14, 2008. Retrieved April 15, 2008.
3. "Xinhua - English". News.xinhuanet.com. 2005-10-12. Retrieved 2013-12-20."

 

[Keel]

China's Yuanwang ships are mobile tracking stations with large radio telescopes

China has a total of 6 Yuanwang space tracking ships. For manned spaceflights, China deploys at least four Yuanwang ships. For unmanned space programs like Chang'e II, China deploys only three Yuanwang ships.

By using interferometry, the three on-board Yuanwang radio telescopes act as a single massive unit that runs the length of the ship.
----------

Yuan Wang class tracking ship - Wikipedia, the free encyclopedia

"Another two Yuanwang-class vessels were launched in Shanghai in early 2007.[1]

Pictures of Yuanwang 6 were published as it has been revealed that both Yuanwang 5 and the newly commissioned ship would be on duty for the Shenzhou 7 mission.[2]

During the Shenzhou spacecraft flights, the four ships are positioned with:[3]

* Yuanwang 1 in the Yellow Sea
* Yuanwang 2 about 1500 km (about 900 statute miles) southwest of French Polynesia
* Yuanwang 3 off the Namibian coast
* Yuanwang 4 off the coast of Western Australia in the Indian Ocean
...
References

1. "Yuanwang Space Tracking Ships". [1]. June 3, 2007. Archived from the original on July 7, 2007. Retrieved July 12, 2007.
2. "远望六号航天测量船交付将执行神七任务". 人 民 网. April 14, 2008. Retrieved April 15, 2008.
3. "Xinhua - English". News.xinhuanet.com. 2005-10-12. Retrieved 2013-12-20."

That is correct @Martian2 but the ships are not as good a platform because the accuracy of equipment can be affected by waves

During the Chang'e missions, ESA has also provided tracking assistance for us like during our Chang'e 3 mission by virtue of our participation in the European VLBI Network (EVN) as detailed in post #1 and 3

Tracking and communication with the spacecraft throughout its cruising phase, was primarily accomplished by two big radio dishes in mainland China, specifically built for deep-space tracking applications. One 115 foot (35-meter dish), which is located at the city of Kashgar in the Xinjiang Region, near the Tajikistan borders, and a 213 foot (65-meter) dish, located at the city of Jiamusi in the Heilongjiang province in northeast China, near the Russian borders.

The European Space Agency (ESA) also provided a communications relay link and tracking support, via its 49 foot (15-meter) ground station in French Guiana, South America, and its Estrack network. Estrack is comprised by a system of ten tracking stations in seven countries, headquartered at the Estrack Control Centre in ESA’s European Space Operations Centre, in Darmstadt, Germany. These dishes will be the primary means of communication with Chang’e throughout the whole duration of its mission as well.

Destination Moon: Chang'e 3 conducts historic soft-landing on the Moon - SpaceFlight Insider

On top of the above, it is a welcoming news for starting a new page of co-operation with Argentinians in deep space tracking
@post 717 credit to @bobsm's posting
Chinese Space Capabilities | Page 48