jgg     2014 34 (2):  169-174    ISSN: 0412-1961  CN: 21-1139/TG STUDY OF CHARACTER OF GPS/GLONASS SATELLITE CLOCK  CORRECTION BASED ON LEAST SQUARE SPECTRAL ANALYSIS 1）Shanghai Astronomical Observatory，Chinese Academy of Sciences，Shanghai 200030 2）College of Surveying and Geo-informatics，Tongji University，Shanghai 200092 Received: 2013-09-26  Revised: null  Online: 2014-04-21 Supporting info