Passive emitter localization using weighted instrumental variables

The linear least-squares algorithms for emitter localization such as the pseudolinear estimator are known to exhibit large estimation bias because of the correlation between the measurement matrix and the bearing noise. The paper presents a new bearings-only emitter localization algorithm with a closed-form solution that overcomes this bias by making use of instrumental variables obtained from a biased location estimate. By way of computer simulations, the new algorithm is shown to outperform the pseudolinear estimator while having a performance identical to that of the computationally more expensive maximum likelihood estimator.