检索结果-南通市图书馆

Precise Positioning Method for Seafloor Geodetic Stations Based on the Temporal Variation of Sound Speed Structure

在线全文

学校读者我要写书评

暂无评论

Journal of Geodesy and Geoinformation Science 2023年第2期6卷 81-92页

作者： Shuang ZHAO Zhenjie WANG zhixi nie Kaifei HE Huimin LIU Zhen SUN Chinese Academy of Surveying and Mapping Beijing 100036China College of Oceanography and Space Informatics China University of Petroleum(East China)Qingdao 266580China Qingdao Institute of Marine Geology China Geological SurveyQingdao 266237China

At present,GNSS-Acoustic(GNSS-A)combined technology is widely used in positioning for seafloor geodetic *** on Sound Velocity Profiles(SVPs)data,the equal gradient acoustic ray-tracing method is applied in high-precision position ***,because of the discreteness of the SVPs used in the forementioned method,it ignores the continuous variation of sound velocity structure in time domain,which worsens the positioning *** this study,the time-domain variation of Sound Speed Structure(SSS)has been considered,and the cubic B-spline function is applied to characterize the perturbed sound *** on the ray-tracing theory,an inversion model of“stepwise iteration&progressive corrections”for both positioning and sound speed information is proposed,which conducts the gradual correction of seafloor geodetic station coordinates and disturbed sound *** practical data was used to test the effectiveness of our *** results show that the Root Mean Square(RMS)errors of the residual values of the traditional methods without sound velocity correction,based on quadratic polynomial correction and based on cubic B-spline function correction are 1.43 ms,0.44 ms and 0.21 ms,*** inversion model with sound velocity correction can effectively eliminate the systematic error caused by the change of SSS,and significantly improve the positioning accuracy of the seafloor geodetic stations.

关键词： GNSS-Acoustic sound speed structure temporal variation seafloor positioning

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

改进视觉前端的视觉/惯导融合定位算法

全球定位系统 2024年第3期49卷 20-27页

作者：李志政聂志喜王振杰张远帆中国石油大学(华东)海洋与空间信息学院山东青岛266580

针对移动机器人在GNSS拒止环境下的高精度定位问题,提出了一种自适应通用角点检测(adaptive and generic accelerated segment test,AGAST)算法改进移动机器人视觉/惯导融合定位系统的视觉前端.该算法通过局部直方图均衡化和自适应阈值... 详细信息

针对移动机器人在GNSS拒止环境下的高精度定位问题,提出了一种自适应通用角点检测(adaptive and generic accelerated segment test,AGAST)算法改进移动机器人视觉/惯导融合定位系统的视觉前端.该算法通过局部直方图均衡化和自适应阈值检测改进视觉里程计(visual odometry,VO)算法,改善特征点提取的质量,提高VO在复杂环境中的定位精度和稳定性;基于因子图优化(factor graph optimization,FGO)算法融合VO和惯性导航系统(inertial navigation system,INS),实现移动机器人的高精度定位.分别采用公开室内、室外数据集进行测试,结果表明:改进算法相比VINS-Mono主流算法室内数据集定位精度平均提升22.8%,室外数据集定位精度平均提升59.7%.

关键词：因子图优化(FGO) 自适应通用角点检测(AGAST) 视觉里程计(VO) 视觉/惯导融合

A joint adjustment method for precise GNSS/acoustic underwater positioning based on single-differenced observations

在线全文

学校读者我要写书评

暂无评论

A joint adjustment method for precise GNSS/acoustic underwat...

A new satellite clock offsets prediction method based on the IGS RTS products

第十四届中国卫星导航年会

作者： Zhen Sun Zhenjie Wang zhixi nie College of Oceanography and Space Informatics China University of Petroleum (East China)

Global navigation satellite system/acoustic(GNSS/A) underwater positioning technique is widely used in the fields of marine scientific research and engineering applications. The conventional single-differenced(SD) positioning method generally treats the position of acoustic transducer obtained by GNSS positioning as known without error. However, error inevitably exists in the estimation of the transducer's position determined by GNSS positioning, and the precision varies at different epochs. Ignoring the errors of acoustic transducer coordinates will lead to a worse estimation of the position of seafloor transponder. In this contribution, a joint adjustment method for precise GNSS/A underwater positioning is presented based on single-differenced observations. The positions of both transducer and transponder are treated as unknown parameters, and the positions of acoustic transducer are considered as virtual observations. The Helmert variance component estimation is used to adjust the weight ratio of two heterogeneous observations. To verify the performance of the proposed method, two field experiments were carried out. The lake experiment results show that the positioning accuracy with the proposed method can be improved by approximately 49% compared with the SD positioning method. The sea experiment results further demonstrate that the proposed method can perform much better than the SD positioning method, with the standard deviation values of coordinate components better than 0.06 m and the root mean square errors of the acoustic ranging residuals better than 0.02 m.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

A new satellite clock offsets prediction method based on the...

Positioning performance assessment of PPP-B2b service: static and kinematic PPP mode

第九届中国卫星导航学术年会

作者： Hongzhou Yang Yang Gao Liang Zhang zhixi nie

Satellite clock offsets prediction is crucial for GNSS applications and has attracted much attention from the GNSS ***,previous satellite clock offset prediction was mostly carried out based on the IGS rapid products or IGS final *** by the long latency of the above products,the predicted satellite clock offset cannot meet the requirements of high precision real-time applications such as real-time *** this paper,a new satellite clock offsets prediction method based on the IGS real-time service(RTS) products is proposed,in which the satellite clock drifts from the broadcast ephemeris are used as the *** the polynomial part,only clock drift and clock drift rate are estimated while the latest clock offsets are directly *** GPS satellite clock offsets are predicted all together by considering the datum change involved in the IGS combination process,which is observed in the IGS01 clock *** results show that the standard deviations of the predicted IGS01 products are 1.408 ns and 0.079 ns for the traditional method and proposed method,*** the IGS03 products,the corresponding standard deviations are 0.243 ns and 0.080 *** proposed satellite clock offset prediction method provides better clock prediction performance based on the IGS RTS products.

关键词： IGS RTS Satellite clock offset prediction clock drift constraint

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Positioning performance assessment of PPP-B2b service: stati...

非线性基线长约束条件线性化近似对模糊度解算的影响

第十三届中国卫星导航年会

作者： Xiaofei Xu zhixi nie Zhenjie Wang Yuanfan Zhang College of Oceanography and Space Informatics China University of Petroleum

The whole Beidou Global Navigation Satellite System（BDS-3） constellation was completed and officially announced to provide global service on July 31, 2020. Apart from the global positioning, navigation and timing（PNT） service, BDS-3 also broadcasts real-time precise point positioning（PPP） corrections by 3 Geostationary Orbit satellites（GEOs） via PPP-B2 b signal. At present, the PPP-B2 b service for GPS/BDS-3 satellites is available for users in China and the surrounding area. In this paper, we conduct the PPP-B2 b static and kinematic tests to evaluate the positioning performance of the BDS-3 new PPP-B2 b service. Regarding PPP-B2 b static positioning performance, the average positioning accuracy are 4.1 cm, 1.8 cm, and 5.2 cm in the east-, north-, and up-components, respectively. Additionally, the average horizontal and 3-dimensional positioning accuracy is about 4.5 cm and 6.9 cm. As to PPP-B2 b kinematic positioning performance, the vehicle test results show that the overall positioning accuracy is 25.7 cm and 40.1 cm in horizontal and vertical components. It could be concluded that centimeter-level positioning accuracy is reached in static scenario, and decimeter-level positioning accuracy can be achieved in kinematic scenario.

关键词： BDS-3 GPS PPP-B2b Precise Point Positioning

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

测绘学报 2015年第2期44卷 168-173,182页

作者：聂志喜王振杰欧吉坤姬生月中国石油大学(华东)地球科学与技术学院山东青岛266580 中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室湖北武汉430077

GNSS动态相对定位中常附加非线性的基线长约束进行解算,而LAMBDA方法只能处理无约束或者线性约束的模型,为了应用LAMBDA方法,应对非线性约束条件进行线性化近似。通常附加该约束后,模糊度固定成功率会提高,但对于超短基线有时反而会降... 详细信息

GNSS动态相对定位中常附加非线性的基线长约束进行解算,而LAMBDA方法只能处理无约束或者线性约束的模型,为了应用LAMBDA方法,应对非线性约束条件进行线性化近似。通常附加该约束后,模糊度固定成功率会提高,但对于超短基线有时反而会降低。何种条件下附加线性化近似的基线长约束条件可以提高模糊度固定成功率尚未有定论。本文基于附加基线长约束的GNSS相对定位数学模型,推导基线长约束条件线性化近似余项对浮点解的最大影响值公式,给出基线长约束能否线性化近似的诊断条件。当该条件满足时,线性化近似余项影响可以忽略,附加线性化近似的基线长约束可以改善浮点解解算精度,提高模糊度固定成功率;若不满足,则线性化近似余项影响可能不可以忽略,附加约束会因浮点解有偏不能固定为正确的模糊度,并通过算例验证了相关结论。

关键词：动态相对定位基线长约束线性化近似余项影响诊断条件

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

水声定位中一种大入射角声线跟踪方法

武汉大学学报（信息科学版） 2016年第10期41卷 1404-1408页

作者：王振杰李圣雪聂志喜王毅吴绍玉中国石油大学(华东)地球科学与技术学院山东青岛266580 海洋国家实验室海洋矿产资源评价与探测技术功能实验室山东青岛266071 中国石油东方地球物理公司河北涿州072751

在高精度水下声学定位中,常采用分层等梯度声线跟踪的方法对水下目标进行定位。但当声线入射角度过大时,该方法入射角的迭代解算会出现发散问题。首先,针对该问题产生的原因进行了分析,并在此基础上提出了一种新的入射角迭代方法,新方... 详细信息

在高精度水下声学定位中,常采用分层等梯度声线跟踪的方法对水下目标进行定位。但当声线入射角度过大时,该方法入射角的迭代解算会出现发散问题。首先,针对该问题产生的原因进行了分析,并在此基础上提出了一种新的入射角迭代方法,新方法采用曲率半径R代替Snell常数p进行迭代。利用500m水深模拟数据进行了验证,结果表明:在声线入射角较小时(如不大于80°),新方法和原方法的定位精度相当;在声线入射角度进一步增大时,新方法的定位效果优于原方法。

关键词：水下声学定位分层等梯度声线跟踪大入射角精度

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

顾及双程声径的常梯度声线跟踪水下定位算法

测绘学报 2022年第1期51卷 31-40页

作者：闫凤池王振杰赵爽聂志喜孙振李伟嘉中国石油大学(华东) 山东青岛266580

高精度水下声学定位通常采用声线跟踪定位算法,但传统的声线跟踪方法一般针对单程声径进行声线弯曲改正,未能顾及船载换能器在声信号往返过程中发生的位移,导致海底应答器定位解算时引入系统性偏差,从而降低海底点定位精度。针对此问题... 详细信息

高精度水下声学定位通常采用声线跟踪定位算法,但传统的声线跟踪方法一般针对单程声径进行声线弯曲改正,未能顾及船载换能器在声信号往返过程中发生的位移,导致海底应答器定位解算时引入系统性偏差,从而降低海底点定位精度。针对此问题,本文提出一种顾及双程声径的分层常梯度声线跟踪水下定位算法。该方法结合水下声信号实际传播路径,根据换能器在声信号发射和接收时刻的位置,构建双程声径水下定位模型,采用顾及双程声径的分层常梯度声线跟踪算法进行解算。采用圆走航观测与交叉十字观测的海上实测数据对方法进行了验证,结果表明,本文方法能显著提高水下定位精度。

关键词：水下声学定位双程声径声速剖面最小二乘法声线跟踪

顾及声速结构时域变化的海底基准站高精度定位方法

在线全文

学校读者我要写书评

暂无评论

测绘学报 2023年第1期52卷 41-50页

作者：赵爽王振杰聂志喜贺凯飞刘慧敏孙振中国测绘科学研究院北京100036 中国石油大学(华东)海洋空间与信息学院山东青岛266580 中国地质调查局青岛海洋地质研究所山东青岛266071

目前广泛采用GNSS-A联合技术进行海底基准站定位,高精度位置反演通常基于声速剖面数据采用等梯度声线跟踪方法实现。但该方法使用的离散声速剖面忽略了声速结构的时域连续变化特性,制约海底点定位精度。本文顾及声速结构时域变化,引入三... 详细信息

目前广泛采用GNSS-A联合技术进行海底基准站定位,高精度位置反演通常基于声速剖面数据采用等梯度声线跟踪方法实现。但该方法使用的离散声速剖面忽略了声速结构的时域连续变化特性,制约海底点定位精度。本文顾及声速结构时域变化,引入三次B样条函数表征扰动声速,基于声线跟踪理论,构建“分步迭代-渐次修正”的位置信息和声速信息迭代反演模型,进行海底基准站坐标和扰动声速的渐次修正。采用南海实测数据进行验证,结果表明:传统不施加声速修正、基于二次多项式声速修正,以及基于三次B样条函数声速修正的方法,对应的观测值残差均方根误差分别为1.43、0.44和0.21 ms;施加声速修正的反演模型有效消除了声速结构变化引起的声速相关系统性误差,显著提高了海底基准站定位精度。

关键词： GNSS-声学定位声速结构时域变化海底基准站