ABSTRACT
This chapter presents an introduction to the issues in actual and lower bound localization accuracies. Several factors influence localization accuracy when using passive or active arrays of sensors. The arrays receive delayed versions of the emitted signal. The chapter explains multiple cross-sections of the general problem. These cross-sections give a good perspective on the encountered problems. The Cramer-Rao lower bound gives the local or small error performance of parameter estimators. Physical instrumentation, that is, maximum likelihood estimator, exists to reach this bound for sufficiently high signal-to-noise ratio and/or long observation time. Lower bounds on global errors exist, that is, Barankin, Battacharya, and Ziv Zakai bounds. Those bounds are based on different assumptions and their results are not directly comparable. While attainability of the Cramer-Rao bound is well established, no comparable result exists for the global bounds.
