| Modern land fighting vehicles are equipped with passive sensors, laser range finders and active radar, all of which can be used to localize a target. Unfortunately, radar and laser warning receivers will also easily reveal and locate a transmitting vehicle. Thus, the replacement of active tracking techniques by more passive means is needed to increase battlefield survivability.; This thesis proposes a recursive Measurement Instrumental Variables Bearings-Only Tracking (MIV-BOT) method for a stationary observer. A smoothing operation directly fuses multi-sensor bearing measurements by exchanging sensor measurements as the instruments in a pseudo linear estimator. The MIV-BOT formulation produces a smoothed velocity estimate parameterized to any position along the target trajectory, which is found from a single laser range finder measurement. Target range predictions, derived from the smoothed two-state velocity estimate, are then used as range measurements in two parallel Kalman filters. The result is a recursive, passive and unbiased fusion scheme. The theoretical development is corroborated by Monte Carlo simulation, in short tracking scenarios. The experimental results show that the fusion scheme produces reliable estimates for non-manoeuvring targets. It is shown, with real target data, that the MIV-BOT fusion scheme can reliably estimate the state of the target using a residual-based track quality indicator. |
