jgg     2013 33 (5):  120-123    ISSN: 0412-1961  CN: 21-1139/TG SATELLITE CLOCK PARAMETER TWO-STEP FIT ALGORITHM FOR  PERIOD OF OUT-OF-VIEW 1) College of Navigation & Aerospace Engineering, Information Engineering University, Zhengzhou 450052 2) The Equipment Research Institute of the Second Missile Army, Beijing 100085 3) Beijing Global Information Application and Development Center, Beijing 100094 Received: 2012-09-26  Revised: null  Online: 2013-10-13 Supporting info