Target localization from bearings-only observations

Present a new method for the determination of the distance to a fixed or moving point (or target) from measurements of its direction (or bearing). The article makes none of the usual presumptions concerning random or systematic errors. Rather, it follows a new estimation principle that is designed to deal with both types of errors and allows one to make predictions regarding the "observability" of various aspects of the kinematic state of the target. Numerical examples for the sonar version of the problem are also included.