The Characteristics of Time Paramerters in GPS Navigation Message
GAO Yu Ping (Shaanxi Astronomical Observatory,The Chinese Academy of Sciences,Lintong,Shaanxi,710600)
GPS navigation message contains satellite's position paramenter and time paramenter, which are necessary to both posisioning and timing. The navigarion message changed with the devlopment of GPS. The characteristics of time paramenters in GPS navigation message and the effect of SA on satellite's clock are discussed briefly in this paper.