jgg     2014 34 (1):  139-143    ISSN: 0412-1961  CN: 21-1139/TG TRI-FREQUENCY CYCLE-SLIP DETECTION AND REPAIR WITH  DIFFERENT SAMPLING INTERVAL Geospatial Information Institute, Information Engineering University, Zhengzhou 450052 Received: 2013-04-18  Revised: null  Online: 2014-01-23 Supporting info