Utilizing the method of mathematic transformation and characteristic of linear matrix equation,the problem of unobservability of a bearings-only target tracking system in noise-free bearings measurements was discussed based on the target and observer traveling in 3-dimensional space with constant velocity or constant acceleration.

This paper studies multi-bearings and first-range method of bearing-only target locating and tracking,gives change relation between bearings and range on bearings-only based on a multi-bearings and first-range.

Weighted method of bearings-only target localization and tracking is presented based on a multi-bearings and first-range least square filter.

This paper puts forward locating and tracking problems of target poly-line moving in bearings-only system.

There are foundational mistakes in some mathematic models about TMA in bearings-only system.

Firstly, the comprehensive comment of nonlinear least-squares algorithms used for TMA in bearings-only system is given.

The own ship deterministic optimal and suboptimal trajectory equations as well as optimal trajectory of bearing-only systems locating and tracking had given at target arbitrariness variable speed and variable course motion or fixed.

Application of nonlinear least square based on genetic algorithms in bearings-only target motion analysis;

Algorithms of bearings-only target motion analysis by two observers;

Algorithm study of anti-outliers for bistatic bearings-only target tracking;

Analysis of single-station bearing-only passive location on sea moving radiators

For overcoming the shortcoming of extended Kalman filter,the paper applies unscented Kalman filter on bearing-only target tracking problem.

This paper puts forward a new linear model for bearing-only single-target tracking problem, discusses its observability, gives its solution of filtering and analytic solution of discrete-time system.