基于船载重力和GNSS的测线式陆海高程传递研究

Precise height data with the unified datum over continent and ocean are needed in the marine engineering, and ocean exploitation, utilization and protection with the development of oceanic stratagem implement and marine economy development in China. The height transfer of high precision through long distance across sea cannot be made cheaply with the routine height measuring methods. A new method to connect heights through long distance across ocean along one sea route is put forward by combining the ship-borne gravimetry and GNSS techniques in the proposal. Based on the astronomical leveling principle, theory and method of route height datum unification and height connection will be researched. Using the least squares collocation, high precise deflections of the vertical along the ship course will be estimated from the marine gravity data determined by the ship-borne gravimetry along the route. Ship-borne GNSS receivers and antennae will be optimally designed to estimate positions, velocities, accelerations and poses of the ship with the single-epoch precise point positioning method. Evaluation and controlling system of ship-borne GNSS data quality will be constructed. Precise sea surface heights along the route will be estimated by studying the floater-borne and ship-borne GNSS technique, establishing the ship sea gauge model and selecting the appropriate filtering method considering effects of storm field and tide. The corresponding softwares will be programmed. Validity and accuracy of the new method will be validated by the experiments of simulation, experimental field and actual field data processing. Consequently the new method will be used to precisely connect heights along the route through long distance across sea, which will be the technique support to collect the marine geographical information in China.

随着我国蓝色战略实施和海洋经济发展，各项海洋工程、海洋开发利用与保护等都亟需高精度的陆海统一的高程资料，常规高程测量方法无法实现低代价、高精度、远距离的高程传递。本项目提出集成船载重力和GNSS的测线式远距离跨海高程传递新方法，根据天文水准原理，开展海上测线式高程基准统一理论和传递方法研究。沿船只航线，进行海洋重力测量，通过最小二乘配置方法，解算高精度航线海洋垂线偏差。优化配置船载GNSS，构建船载GNSS数据质量评价和控制体系，进行海洋环境下的单历元相对定位/精密单点定位研究，实现位置、速度、加速度和姿态的高精度测量。开展浮子GNSS研究，建立船只吃水深度模型，研究顾及风浪场和潮汐影响的滤波方法，实现航线海面高的精确测量。编制相应软件，通过模拟实验、实验场实验和实测数据处理，验证本项目所提方法的正确性和精度，实现远距离测线式跨海高程传递，为国家海洋基础地理信息获取提供技术支撑。

高程作为基础地理空间信息，在社会发展、国民经济建设和国防建设中具有举足轻重的作用。随着我国蓝色战略实施和国防建设发展，各项海洋工程、海洋开发利用与保护、海洋科学研究、海疆保护等亟需陆海统一的精确高程资料，需要统一的陆图和海图的垂直基准。常规陆海高程测量方法无法实现远距离、高精度、低代价的跨海高程统一和传递。本项目将天文水准原理首次引用到海洋测绘中，创新性地提出了集成船载重力和GNSS的测线式远距离跨海高程传递新方法。主要研究内容包括：①根据天文水准测量原理和误差传播定律，推导了海上测线式高程传递公式，确定了垂线偏差、距离、分段数、大地高和重力数据精度对跨海高程传递的误差影响；②通过沿测线往返测重力数据共线平差和滤波有效改善测线重力数据精度，构造了两种扰动位和重力场场元之间的协方差函数（基于扰动位球谐系数展开的全球表达形式的协方差函数，基于平面内拉普拉斯方程边值问题的局部扰动位协方差函数），分析了航线重力异常空间分辨率对测线式垂线偏差的计算误差和代表误差的影响，提出了由船载重力计算高精度测线式海洋垂线偏差的集成移去-恢复技术和最小二乘配置方法，提出了协方差函数距离参数与重力异常噪声方差最优组合的最小二乘配置优化方法；③提出了船载GNSS单历元PPP解算海面高的航线共线/交叉点平差方法，有效消除PPP、姿态和吃水等误差影响，提出了基于卫星测高海面高约束的船载GNSS单历元PPP海面高解算方法和基于单基准站的单历元差分PPP方法，进一步改善船载GNSS海面高测量精度。本项目进行了2个试验：①青岛沿海有两个水准点NZ和SLZ，海上航线距离为11km，本项目获得的高程与陆上水准测量高程之差为0.0191m；②青岛SLZ点和福建草屿P005点之间的海上航线距离达到1200km，本项目计算的高程与陆上水准测量高程之差为0.1005m。两个试验结果均能满足国家三等水准测量精度要求。