GNSS/SINS组合进行惯性重力测量误差分析

针对INS技术及GNSS数据处理技术,分析中国实现惯性重力测量的可能性。分析结果表明,目前中国GNSS观测与数据处理技术用于惯性重力测量已不存在技术上的困难,而国产惯性测量系统的性能指标要达到1×10^-5 ms ^-2 的重力观测精度虽有一定的困难,但随着惯性测量系统技术的进步,利用国内研制的捷联式惯导与GNSS联合进行惯性重力测量已成为可能。     

消费级无人机与GNSS接收机在地形图测绘中的应用及精度分析

随着倾斜摄影测量技术和人工智能的发展,消费级无人机在测绘行业得到了较好的应用.本文主要利用大疆精灵4和GNSS接收机,采用现场外业航拍、三维建模、空三解算、图形绘制等技术方法对测区进行大比例尺地形图测绘,利用全站仪对特征房角点进行地形图精度分析.通过实例分析,测图精度满足1∶500大比例尺地形图要求,提高了工作效率、节...     

Forearc deformation and tectonic significance of the ultramafic Molucca central ridge, Talaud islands (Indonesia)

Abstract The Molucca Sea is a narrow basin located south of Mindanao (Philippines) and underlined by a north-south ophiolitic ridge. This ridge represents the outer ridge of the Sangihe subduction zone and emerges by uplift in the central part of the basin, in the Talaud Islands. Field studies indicate that forearc sediments rest uncomformably on (i) a dismembered ophiolitic series and (ii) thick melanges. Structural analysis indicates two deformation events, one of which is oriented east-west coaxial with the present state of strain. We interpret the earlier (N20°E) direction as a thrusting event that affected an ophiolitic basement associated with the edge of the Celebes Sea. Thrusting within the oceanic crust and sediments also generated olistostromes (melanges). The style of deformation is characterized by flattened rhombs of peridotites which exists in situ in the upper section of the crustal sequence and were also found inside the melange. Incipient Sangihe subduction around 15 Ma uplifted the deformed crust and buried the melanges beneath the forearc sediments. Recent east-west shortening during subduction of the Snellius Plateau reactivated the melanges within thrusts cutting the forearc series.     

基于高精度GNSS定位解算及姿态数据获取潮位研究

文中基于GNSS高精度定位解算成果中的高程数据,利用测船航行过程中实时采集的姿态数据进行涌浪补偿,并根据船舶每天的吃水变化将GNSS天线高调整为瞬时水面高;通过相邻水位站的比对获取GNSS高程与深度基准面的高差,对获取的瞬时水面高进行基准面变换,得到基于深度基准面的潮位值。针对以上技术路线进行了研究,并在工程中进行了验证,成果统计数据证明,提取的潮位满足规范要求,可在实践中应用推广。     

GNSS浮标高程测量精度的影响因素研究

针对高度计定标检验的需求,研制了GNSS浮标,并在天津市于桥水库和威海市石岛镇分别进行了浮标性能测试。通过对影响浮标数据处理精度的因素进行研究,为GNSS浮标数据处理方法建立了完整的技术流程,使其满足高度计定标检验的需求。结果表明:GNSS浮标可以满足高度计定标检验的需求;但需特定的数据处理方法。(1)在基准站数据处理中,卫星截止高度角选择为5°~15°,数据采集时间不少于24 h;(2)浮标数据处理模式选择为自动模式,并对其进行移动平均滤波或中值滤波处理后,流动站解算结果最优;(3)GNSS浮标的水面高程测量精度优于1 cm;(4)受到GNSS本身的限制,当浮标距离GNSS基准站越远,浮标数据的解算精度越低。     

Improved Method to Detect and Repair Cycle Slip for GNSS Medium–Long Baseline in Real-Time Marine Surveys

Distance-related errors complicate the resolution of real-time ambiguity in medium–long baseline marine surveys. Therefore, detection and recovery of cycle slips in real time is required to ensure high accuracy of global navigation satellite system positioning and navigation in marine surveys. To resolve this, an improved method was presented, where linear combinations of the triple-differenced (TD) between carriers L₁ and L₂ were formed for a wide lane and free ionosphere. To overcome severe ill-conditioned problems of the normal equation, the Tikhonov regularization method was used. The construction of a regularized matrix by combining a priori information of known coordinates of reference stations, followed by the determination of the corresponding regularized parameter are suggested. A float solution was calculated for the TD ambiguity. The search cycle slip (TD integer ambiguity) was obtained using the least-squares ambiguity decorrelation adjustment (LAMBDA) method. Using our method, cycle slips of several reference station baselines with lengths of a few hundred to one thousand kilometers were detected in real time. The results were consistent with professional software, with a success rate of 100%.     

基于自动跟踪技术检测GNSS动态测量精度方法

提出一种基于TDA5005高精度全站仪对GNSS定位设备进行自动跟踪测量,通过自动控制、时间同步、姿态改正、空间基准统一等步骤,实现对动态环境下GNSS设备单历元定位精度进行检测。设备检测既可在海上也可在陆地上进行,自动化程度高,操作简便,以期对GNSS的应用有一定的指导和借鉴意义。     

精密单点定位技术在海上工程中的应用

结合海上科研工程实践,对GPS精密单点定位模型及数据处理方法进行研究,并采取陆上静动态定位和海上动态定位试验进行了精密单点定位精度统计和分析。结果表明:在超出常规差分定位基线长度限制的广阔海域,采用精密单点定位技术可实现亚米级实时动态定位,为海上高精度实时动态定位应用提供了技术依据。     

Precise Geoid Determination over Hong Kong from Heterogeneous Data Sets using a Hybrid Method

ABSTRACT

This study attempts to develop a methodology to construct a high-precision geoid model (HKGEOID-2016) over Hong Kong. To achieve this objective, a hybrid method is employed in this article. The proposed method involves three steps: the combination of multisource data; the construction of gravimetric geoid model using the remove-restore technique and Molodensky's theory; and the optimal combination of heterogeneous height data, improved by the evaluation of stochastic models through the variance component estimation method and assessment of the parametric model. The accuracy of the constructed geoid is evaluated with independent GNSS/leveling data. Numerical results indicate that external precision of 1.5 cm level is achievable. Furthermore, compared with the former geoid model HKGEOID-2000, the proposed procedure in this study improves the accuracy of the geoid significantly.     

Dynamic Modeling and Investigation of Maneuver Characteristics of A Deep-Sea Manned Submarine Vehicle

A deep-sea Manned Submarine Vehicle (MSV) is usually required to move at a low forward speed and a low rotational speed when it executes investigation tasks. In this condition, the motion is in large drift angles, and the maneuverability hydrodynamic forces cannot be expressed properly in the conventional mathematical model of submersible motion. In this paper, firstly, a general equation of MSV with six-freedom motion is presented, and the numerical simulation of descent/ascent motion and helix motion is c...