| 词条 | BPC (time signal) |
| 释义 |
BPC is the callsign of a time signal broadcasting from the BPC Shangqiu Low-Frequency Time-Code Radio Station, cooperatively constructed by the National Time Service Center of the Chinese Academy of Sciences and Xi’an Gaohua Technology Co., Ltd. , since April 25, 2002. BPC transmits a time signal on 68.5 kHz, which can be used for synchronizing radio controlled clocks. As opposed to other time signal transmitters, the signal format is not published openly; a special license is required. The transmission site is situated near Shangqiu, Henan Province[1] at {{Coord| 34.457|N|115.837|E|type:landmark_region:CN-61|display=it}}.[2] BPC broadcasts at 90 kW for 21 hours per day, with a 3-hour break from 05:00–08:00 (China Standard Time) daily[2] (21:00–24:00 UTC). BPC includes both conventional amplitude modulated time code and additional spread-spectrum time code, about which little is known.[3] References1. ^{{cite web|url=http://www.cl.cam.ac.uk/~mgk25/time/lf-clocks/ |title=Low-frequency radio time signals |publisher=Cl.cam.ac.uk |date= |accessdate=2011-10-20}} 2. ^1 {{cite web|url=http://www.time.ac.cn/serve/e_c.htm |title=Archived copy |accessdate=2013-03-16 |deadurl=yes |archiveurl=https://web.archive.org/web/20120617220116/http://www.time.ac.cn/serve/e_c.htm |archivedate=2012-06-17 }} 3. ^{{Citation |title=Additional spread spectrum modulation timing method in BPC |last1=Feng |first1=Ping |last2=Wu |first2=Guichen |last3=Bai |first3=Yan |last4=Ding |first4=Xiaofeng |date=August 2010 |journal=Sixth International Symposium on Precision Engineering Measurements and Instrumentation. Proceedings of the SPIE |volume=7544 |pages=75441X–75441X–6 |editor1=Tan, Jiubin |editor2=Wen, Xianfang |doi=10.1117/12.885845 |bibcode=2010SPIE.7544E..68F |series=Proceedings of SPIE}} External links
1 : Time signal radio stations |
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