e-Navigation战略下提出的基于船舶自动识别系统（AIS）和中频信标系统的陆基导航系统，是克服全球卫星导航系统脆弱性，保障船舶航行安全最为经济的解决方案。但目前的AIS和中频信标系统是通信系统，其岸站覆盖条件在很多情况下很难满足传统测距模式定位参考点数目的要求，且海上无线电信号传输中存在的非直达波会严重影响船舶定位精度。因此，e-Navigation提出的陆基导航系统对于船舶定位是非理想的，本项目拟在上述非理想环境下探讨船舶定位新方法。利用自组织协作理论和位移辅助算法，解决岸站非定位覆盖限制下两个参考点的船舶定位问题；建立海面非直达波（NLOS）传播模型，利用滤波算法实现抗NLOS的船舶非线性动态跟踪定位，提高定位精度；建立以不同度量指标为依据的通用定位精度评估体系，给出克拉美罗下界。通过本项目的研究，为e-Navigation提出的测距模式陆基导航系统实现奠定理论基础。

In the e-Navigation, the most economical ground-based navigation system solution is adding the ranging mode on the basis of the existing Automatic Identification System (AIS) and MF beacon system, to overcome the vulnerability of Global Navigation Satellite System (GNSS) and guarantee the safety of maritime navigation. However, the AIS and MF beacon system is a communication system essentially. It is difficult to meet the number request of positioning reference nodes in traditional ranging mode under the coverage of the existing shore stations in many cases. Moreover, the positioning accuracy is affected seriously by the Not Line of Sight (NLOS) signals in maritime radio signal transmission. The novel position estimation methods in the above two types of non-ideal conditions of land-based radio navigation system for e-Navigation is investigated in this project. To solve the vessel positioning problem under the limit coverage of shore stations, the self-organization collaboration positioning and the novel displacement assisted positioning of two reference points are investigated. The model of signal propagation characteristics under maritime NLOS environment is proposed. A nonlinear dynamic tracking positioning method based on the filter algorithm is proposed to against NLOS interference effectively and improve the positioning accuracy of vessels. The positioning accuracy evaluation system according to different metrics is given to assess the positioning method. And Cramer-Rao lower bound of the proposed method is calculated. Through this project research, a theoretical foundation is laid for the non-ideal conditions of the ranging mode land-based navigation system for e-Navigation.