Abstract: The problems met in high dynamic circumstances during estimating GPS signal parameters and detecting data transition are analyzed. The signal parameters are estimated through extended Kalman filter (EKF) algorithm. The pseudonoise (PN) code tracking through digital delay-locked loop (DDLL) and carrier assistant technology are discussed. And a simple data transition detection and parameter correction method is studied emphatically. The tracking performance and tracking error of the algorithm are analyzed through simulation. The simulation shows that this data transition method conduces to improve the parameters estimation precision, and the algorithm dynamic performance is ameliorated too.

Key words: parameter est imat ions, p seudo random codes, algo rithm s, GPS, h igh dynam ic