I would like to share with you a beautifully-written scientific introduction about Beidou system: its origin, development, application, and prospect.  I admire the author could explain such profound theories in simple, humorous language so as to make it easily to be understood.  To me, the report is also a bitter-sweet history of modern China, in miniature and in retrospect.

https://user.guancha.cn/main/content?id=67463&page=1