A New Measurement Model of Clock State Tracking From Analysis of Observability

It can be found by simulations that there exists instability in the solution of distributed Kalman filter in the state tracking problem of distributed clock. This article has analyzed that the premise of obtaining the deterministic state estimation is ensuring the observability of system. Then, an observable measurement model for constructing a new comparative transformation of minimum mean square error (MMSE) oriented to basic measurement unit is proposed. Based on the vector operation for vector space of measurement state, while ensuring the observability of system, a state uncoupled measurement equation that has approximately equivalent performance with MMSE is established, and the algorithm has the scale extensibility of MMSE measurement performance. The algorithm realized the distributed tracking of clock state by updating of measurement value oriented to the two-way message exchange.