ABSTRACT

This chapter discusses the problem of estimating the location and velocity of a sonar contact via observation and processing of acoustic data. It provides a general perspective on contact localization and motion analysis (CLMA) in the ocean environment. The chapter introduces representative CLMA problems and also illustrates that the difficulty in solving these problems increases as the geometric relationship between contact and observer becomes nonstationary. It highlights the types of errors encountered in the ocean environment, which tend to make the various classes of problems more difficult to solve, are categorized and techniques for reducing these errors. For three-dimensional tracking, it is well known in radar-sonar work that serious degradation of depression/elevation angular measurements is caused by multipath propagation. Bias in range becomes significant as the contact range increases, as the contact moves away from sensor array broadside, and as the time delay variance deteriorates with signal and noise conditions.