INS-Aiding Using Bearings-Only Measurements of an Unknown Ground Object

摘要

A theory is developed for Inertial Navigation System (INS) aiding using passive, bearings-only measurements over time of an unknown ground object. The theory is developed in the context of kinematic navigation. Stand-alone bearings-only measurements over time of an unknown, but stationary, ground object and kinematic navigation are shown to yield estimates of the aircraft's angle of attack, α, and sideslip angle, β, which allows an update of the aircraft's attitude. Furthermore, it is shown that a baro-altitude measurement and knowledge of the ground object's elevation make it possible to estimate the aircraft's ground speed and update the aircraft's positional navigation variables. Therefore, damping of the error in the INS-provided position estimate is achieved. Furthermore, the ground object's position relative to the aircraft is also obtained, which affords the ground object's geo-location.