摘要
本文基于贝叶斯估计采用同时估计海底应答器位置和声速水平梯度的策略处理了水深约3 km的GNSS-A观测数据,分别在单应答器模式、多应答器阵列模式下,分析了航迹几何构型、参数初值以及参数估计策略对海底固定应答器和锚系应答器三维定位精度的影响.结果表明:应答器位置后验不确定度与先验不确定度呈正比关系,其比例系数对于单站模式约为0.1,对于多站模式约为0.05;观测时延残差均方差(RMS)在单站模式下约为0.6 ms,多站模式下约为4.5 ms;圆形测线由于测量时间较短,声速水平梯度变化不大,因此同时估计海底应答器位置和声速水平梯度能够获得较高的定位精度;然而,由于井字形航迹的走航时间较长,声速水平梯度变化较大,该估计策略已不再适用,因而精度最低;圆形测线对参数初值先验精度要求较高;当换能器与GNSS天线的臂长先验精度较高时,对于圆形测线,估计该参数并不能显著提升定位精度.
This paper uses Bayesian estimation to analyze the Global Navigation Satellite System-acoustic(GNSS-A) observation data at a water depth of 3 km by simultaneously estimating the position of the transponder and the horizontal sound speed gradient. The effects of geometric tracks, initial parameter values, and parameter estimation strategies on the three-dimensional positioning accuracy of the underwater transponder are analyzed in the single-transponder mode and the multi-transponder array mode, respectively. The results show that the posterior uncertainty of the transponder position is proportional to the prior uncertainty, and the coefficient is ~0.1 for the single-transponder mode and ~0.05 for the multi-transponder mode. The Root Mean Square(RMS) of the observed travel time delay residual is ~0.6 ms and ~4.5 ms for single-transponder mode and multi-transponder mode, respectively. Due to the short measurement time of the circular track, the horizontal sound speed gradient changes little and the higher positioning accuracy can be obtained. However, the method is not suitable for the tic-tac-toe track due to the obvious change of the horizontal sound speed gradient during the longer measurements. The positioning accuracy of the circular track is closely related to the initial values. When the priori accuracy of offset of the transducer relative to the GNSS antenna is high, for a circular survey line, estimating this parameter cannot significantly improve the positioning accuracy.
作者
明锋
杨元喜
曾安敏
MING Feng;YANG YuanXi;ZENG AnMin(State Key Laboratory of Geo-Information Engineering,Xi'an Research Institute of Surveying and Mapping,Xi'an 710054,China)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第3期951-960,共10页
Chinese Journal of Geophysics
基金
国家自然科学基金项目(41931076)
崂山实验室科技创新项目(LSKJ202205101)
国家重点研发计划项目(2020YFB0505801)资助。
关键词
水下声学定位
海底大地测量
声速剖面
几何构型
贝叶斯估计
Underwater acoustic positioning
Seafloor geodesy
Sound speed profile
Geometric configuration
Bayesian estimation
