atomic clock for Beidou navigation satelite Dec 2, 2015 21:11:30 GMT -5 Quote Select PostDeselect PostLink to PostBack to Top Post by challenge on Dec 2, 2015 21:11:30 GMT -5 bbs.wforum.com/wmf/bbsviewer.php?trd_id=315684two hydrogen atomic clock were develop,one from shanghai R and d the other from lab no. 203.