A Unified Approach to the Error Analysis of Augmented Dynamically Exact Inertial Navigation Systems

A model for pure inertial navigation systems is defined which describes a wide class of dynamically exact systems for terrestrial and space applications. Based on this model a standard error block diagram is described and it is shown how the conventional simplifying assumptions lead to the specific version used for slow moving terrestrial applications. To efficiently treat augmented inertial systems, a generalized approach to error analysis of estimation systems is introduced. This approach, discussed in an earlier paper, is amplified as it pertains to augmented inertial systems. It is shown how the standard error propagation block diagram can be used to place the augmented inertial navigation system error analysis in the canonical form necessary for a generalized error analysis. Augmentations considered are position, velocity and attitude fixes. Specific examples are given.