jgg     2014 34 (3):  178-182    ISSN: 0412-1961  CN: 21-1139/TG STUDY ON ELIMINATION OF MULTIPATH ERROR IN PPP BASED ON  SIDEREAL FILTERING 1）College of Electronic Science and Engineering，National University of Defense Technology， Changsha 410073) 2）Jiangnan Institute of Computing Technology，Wuxi 214083 Received: 2013-11-18  Revised: null  Online: 2014-05-28 Supporting info