Local observability matrix and its application to observability analyses

A local observability matrix for a linear time-varying system is introduced. The matrix is useful for observability analysis; it is much easier to use than the usual observability grammian for linear time-varying systems. The matrix is applied to a terrain-aided inertial navigation system to reveal the observability of the system in terms of the nature of the terrain. Results of a simulated covariance analysis are presented and discussed