The System: China launches BeiDou-3 twins

February 7, 2018  - By
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China launches BeiDou-3 twins

China launched two BeiDou-3 navigation satellites into space on Jan. 12 as part of efforts to enable its BeiDou system to provide navigation and positioning services to countries along the Belt and Road by the end of 2018. The Belt and Road Initiative aims to create the world’s largest platform for economic cooperation, encompassing China, Southeast Asia, South Asia, Central and Western Asia, Middle East and Africa, and Central and Eastern Europe.

The twin satellites are coded MEO-7 and MEO-8, the 26th and 27th satellites in the BeiDou Navigation Satellite System. They are based on a newly developed dedicated satellite bus that features a phased-array antenna for navigation signals and a laser retro-reflector. They each weigh about one metric ton, and both have two deployable solar arrays; their design life is 12 years. This was the first BeiDou launch in 2018, which will see an intensive further launch schedule throughout the year.

In his December 2017 “Directions” article in GPS World, Changfeng Yang, chief BeiDou system architect, wrote that “Eighteen BD-3 MEO satellites and one BD-3 GEO satellite will be launched by around the end of 2018. Upon the deployment of those 19 satellites, BD-3 will possess the initial operational capability and serve the countries along the Belt and Road.”

This would bring the constellation to an initial operational capability before the end of this year. China targets completion of the fully operational global system in 2020.

B1C, B2A Control Document. On the Chinese part of the BeiDou website, there is now an English version of the Test ICD for the B1C and B2a signals. The link to the website item is www.beidou.gov.cn/icdb1cb2abeta.html, and the actual document is at www.beidou.gov.cn/attach/beidou/2333234155.pdf.


More interference potential from another tower set

Satellite operator Iridium asked the Federal Communications Commission (FCC) in April 2017 to modify its license to add a new class of ground stations called Certus for expanded terrestrial, maritime and aeronautical operations.

Iridium’s 66-satellite constellation provides, in addition to mobile communications signals, the Satelles time and location service: microsecond timing accuracy and 20- to 50-meter unaided position accuracy worldwide (see the “Innovation” column, July 2017 GPS World).

GPSIA. The GPS Innovation Alliance (GPSIA) commented in September, “GPSIA seeks to ensure that radio navigation satellite service (RNSS) receivers operating in the 1559–1610 MHz band are adequately protected from out-of-band emissions (OOBE) generated from the new Certus mobile Earth station (MES) terminals that will operate on the second-generation Iridium satellite system.

“GPSIA and Iridium are actively engaged in constructive discussions regarding the adequacy of that protection, but no final resolution has yet been reached. [….]

“In the unlikely event that GPSIA is unable to reach an agreement with Iridium, it asks the commission to impose limitations on the operation of Certus terminal devices to protect GPS/RNSS operations in the 1559–1610 MHz band at a level equivalent to what terrestrial terminals in the same and other frequency ranges provide at –95 dBW/MHz.”

Iridium Certus infographic.

Iridium Certus infographic.

Hexagon. Hexagon, the parent company of GPS manufacturer NovAtel, commented on Jan. 8, “Certain statements in the modification application regarding output power and amount of terminals to be deployed cause great concern regarding the unimpeded operation of radio navigation satellite service (RNSS) receivers. The application does not include enough information to simulate the impact properly.

“Hexagon politely requests that the FCC will exercise the same due diligence [as] during previous modification applications close to the RNSS bands (for example docket 11-109) and establish a technical working group or a similar testing process that ensures unimpeded coexistence of the modified Iridium terminals with the established RNSS systems.”

Documents related to the case can be found here, on the FCC International Bureau website.


Galileo security center moves to Spain

The Galileo Security Monitoring Centre (GSMC) for the European Union’s Galileo satellite system will move from the United Kingdom to Madrid, Spain, as a result of Brexit.

The center, not yet fully operational, is expected to grow to a staff of as many as 30. It controls access to the satellite system and provides around-the-clock monitoring when the main security center near Paris is offline.

The GSMC is operated by the European GNSS Agency. It is one of a number of EU institutions leaving the UK as a result of the 2016 referendum vote.

Spain has another of the fundamental centers of the program, the Loyola de Palacio GNSS Service Center, also in Madrid.

About the Author:


Tracy Cozzens has served as managing editor of GPS World magazine since 2006, and also is editor of GPS World’s sister website, Geospatial Solutions. She has worked in government, for non-profits, and in corporate communications, editing a variety of publications for audiences ranging from federal government contractors to teachers.

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