List of symbols
$\mathit{V}$	velocity vector
${\mathit{V}}^{\prime }$	acceleration vector
${\mathit{V}}^{″}$	Jerk vector
${\mathit{X}}_k$	state, ‘k’ represents the time epoch of the data sample
${\mathit{W}}_k$	state noise
${\mathit{Z}}_k$	measurement
${\mathit{U}}_k$	measurement noise
$z_{code}$	the output of code phase discriminator
$z_{carrier}$	the output of carrier frequency discriminator
$e_{j,k}$	line-of-sight direction unit vector between the receiver and the jth satellite at time epoch k
$R_k$	measurement error covariance matrix
$Q_{k-1}$	represents the covariance matrix of the prediction error ${\mathit{W}}_{k-1}$
$X_{k|k-1}^{*}$	represents the weighted center matrix,
$S_{zz}$	square root of the innovation covariance matrix
$S_{Q,k}$	square root factor of $Q_k$
$S_{R,k}$	square root factor of the measurement error covariance matrix $R_k$
${\gamma }_{k|k-1}$	weighted center matrix
$K_k$	filter gain
${\widehat{z}}_{ k|k-1}$	measured predicted value
$S_{ k|k}$	square root factor of the state estimation error covariance matrix