Quantifying Observability and Analysis in Integrated Navigation

This paper concerns the problem of quantifying the observability of different states in linear (or linearized) time-varying systems with focus on the usability to integrated navigation. The main goal is the derivation of a novel scalar method to measure the degree of observability in order to quantitatively analyze the observability of each state variable of a system. The new proposed observability analysis method is easily employed in practice with less computer memory and clearer physical meanings. The application to integrated navigation systems was illustrated to analyze the observability properties of navigation error-states. According to the simulation results, the degree of observability can help us to quantitatively compare the observability of each state variable and further function as an indicator to analyze the influence of physical model parameters on the observability and estimability of navigation errors.