Mysterious ‘Pips’ from the Chinese JILIN Constellation

Why is an imaging satellite constellation acting like a mobile-satellite communications system?

China’s first self-developed commercial remote sensing satellite system known as JILIN is sending strange wideband data pips in a quiet piece of spectrum on L-band. The JILIN system is operated by Chang Guang Satellite Technology Company in Beijing. No public references have been found by the author about what these emissions from the satellites purpose is.

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You can call me Dmitry Meyer…

History Repeats Itself

Russia operates a constellation of satellites in high Earth orbit called Meridian (меридиан). These satellites perform a critical communications purpose for Russia as much of its land mass is not well served by geostationary satellites. Therefore, you would think this constellation would be held to the highest operational level. Well it’s not as radio amateurs have observed. This fact could raise questions about Russia’s ability and preparedness to act on their recent veiled threats of nuclear war.

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Chang’e 5 Returns to the Moon

Chang’e 5 has quietly departed from the Sun-Earth L1 point to enter a distant retrograde orbit (DRO) of the Moon, a first.

Pre-empting NASA’s planned 1st use of the orbit during Exploration Mission 1 later this year.

Silence from China.

Off Station

In mid August 2021, the Chang’e 5 service module without any notice was noted to not be on station near the Sun-Earth L1 point where it had been since mid-March 2021. Observers were quick to reacquire the spacecraft’s X-band beacon and it was not long before it was clear from the data that Chang’e 5 was headed back to the Earth-Moon system where it would ultimately enter a Distant Retrograde Orbit (DRO) of the Moon.

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Basic Orbital Dynamics

There has been a recent surge in interest in a software package written by Cees Bassa known as ‘strf’, Sattools Radio Frequency.  Once over the initial installation and basic usage hump users quickly reach a wall about how to use the software because of a limited understanding of orbital dynamics.  I hope this brief post will help users understand some of the basic concepts so they can use strf as a tool.

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