jgg     2014 34 (4):  123-126    ISSN: 0412-1961  CN: 21-1139/TG BEIDOU CODE DIFFERENTIAL POSITIONING BASED ON WEIGHTED  MEASUREMENTS CARRIER PHASE SMOOTHING 1）Institute of Surveying and Mapping，Information Engineering University，Zhengzhou 450052 2）Xi’an Information Division of Surveying and Mapping，Xi’an 710054 3）Beijing Satellite Navigation Center，Beijing 100094 Received: 2013-09-01  Revised: null  Online: 2014-07-22 Supporting info