全站仪遥测目标三维坐标的新方法

研究了利用全站仪悬高测量功能和前方交会来测定某些不能放置棱镜的目标点三维坐标的一种方法,并对所得到的结果进行误差分析,证明该方法测量精度满足工作要求.     

徕卡TCM电动全站仪测量系统在水域测绘中的应用

徕卡TCM电动全站仪是一种全新的自动动态跟踪型全站仪,用于近程、大比例尺水域测量。它只是岸上一个距离——方位测量系统。测量跟踪都是连续自动的。测量数据通过数据传输链(如UHF、VHF电台)传送到测量船。再由船上计算机计算点位,实施实时导航。按一定时间间隔或一定距离差选取定位点平面坐标,驱动测深仪测深。磁盘记录定位时间、点位平面坐标和水深值。利用全站仪进行水域定位虽早已有之,但尚不能解决大比例尺导航定位和测深之间的时间延迟问题,导致测深时往返测线水深不符。利用徕卡TCM电动全站仪测量系统,可有效地解决以上问题,确保测深精度。     

TCM全站仪导航、定位、潮位改正海测一体化应用

TCM电动全站仪是一种具有自动照准预设方向、能自动纵转望远镜,EDM迅速准确连接,能用RS232接口输出数据的全新马达驱动的电子全站仪。其配置的自动跟踪目标装置ATR1与全站仪测距系统及视线同轴,即使对在仰角和倾角很大的测点目标也能追踪如常。TCM电动全站仪配置GRZ4 360°全反射棱镜,使得持标员无需顾及棱镜反射面是否对准全站仪。TCM电动全站仪有效工作距离在一般大气条件下,ATR1全反射棱镜的工作距离为1000m(可满足大比例尺海上测绘范围     

RTK技术在杭州湾跨海大桥桥位地形测绘中的应用

介绍了RTK技术在杭州湾跨海大桥桥位地形测绘中的应用,并对其定位结果进行了精度比较与分析,结果表明:RTK定位测量的点位精度可达厘米级,各点位之间不存在误差积累,与全站仪等测量手段取得的结果符合得较好,可以用来代替二三级导线控制测量和等外水准等测量方法;流动站与基准站的距离在10km范围以内时,应用RTK技术对近岸水下地形进行测量具有方便、快捷、精度高等特点,但当此距离超过10km时,其精度则难以保证。杭州湾跨海大桥施工时应用RTK技术进行定位、高程测量,可提高工作效率和成果的质量。     

全站仪自由设站应用于航道控制测量的图形研究

利用全站仪自由设站测边交会确定待定点的坐标,在航道控制测量工作中得到较好的应用。为研究待定点的精度与交会图形之间的关系,在推出全站仪自由设站测边交会精度估算公式的基础上,对其有利图形进行了分析,并通过实例证明:当采用对称交会(β1=β2),且交会角γ>90°时,交会图形最为有利。     

RTK布设高精度控制点的可行性分析

GPS RTK可以实时获取流动站的坐标,但无法确定点位坐标精度的可靠性。利用高精度基线检定场对RTK测量成果的精度估计进行了研究,证明在具备高等级已知点位成果时RTK测量可用于获取较高精度的控制点。     

一种用于海上打圆桩过程监测的新型测量方法

针对打桩定位的测量方法,探讨了一种用于海上打圆桩过程监测的新型测量方法,使用全站仪无棱镜模式对圆桩横切面进行数据采集,应用最小二乘原理迭代拟合横切面,得到拟合圆心的坐标及圆半径,进而解算桩顶位置和高程、桩倾斜度及多桩控制,实现打桩过程动态监测。经过某项目打桩案例实践,验证了该测量方法的可行性和正确性。     

含有粗差的起始数据对水下地形测量的影响及修正

针对含有粗差的起始数据导致的错误碎部点成果,对粗差产生的途径进行了分析,给出了进行改正计算的必备条件,最后结合实际例子进行了计算验证。结果表明改正计算方法在理论上是严密的,在实际工作中也具有可操作性。     

全站仪的补偿与改正研究

为提高全站仪的测量精度,分析研究了全站仪的补偿与改正方法。基于全站仪三轴误差对角度测量的影响规律和双轴补偿器的工作原理,着重探讨了正确使用补偿装置对全站仪进行水平度盘和垂直度盘读数的补偿与改正。     

摄影全站系统及其精度评定

摄影全站系统是成熟的数字摄影测量技术与高精度工程测量仪器（全站仪）的集成,可以实现无接触和无控制测量,对摄影测量的发展具有重要的作用。以GFF-7000I摄影全站系统为研究对象,分别对其简单测量模式和标准测量模式进行了不同距离上的精度测试,对摄影全站系统的应用具有一定的指导意义。     

航空摄影测量技术在海岛礁测绘的应用

在完成海岛像控测量、野外调绘、空三加密、内业测图等航空摄影测量技术流程,测绘比例尺1:10000海岛地形图,制作相应的数字高程模型、正射影像图等产品的基础上,总结了航测技术应用于海岸、海岛地形测绘的技术方法、作业流程,并将航测成果与常规海岸地形测量成果进行比对,得出了航测成果精度能够满足<海道测量规范>要求,航测技术可...     

基于多源数据融合的典型海岛三维形貌表征方法研究

随着海岛开发利用和基础设施建设的频繁,高效、精准地获取海岛形态基础数据就显得尤为迫切。三维地形地貌探测和构建技术的日臻完善,及时解决了海岛基础勘测时间长、效率低、精度小的问题。文章通过三维激光扫描和无人机航测手段,全覆盖扫描广西小庙墩(炮台口)海岛表面形态,结合RTK-DGPS实测验证和近景摄影测量,获取海岛实景,运用Geomagic Studio和Smart3D等软件,构建典型海岛三维数字高程模型(DEM),融合多源数据和海岛实景,还原海岛高精度仿真三维形态。为高精度勘测海岛提供有效手段,为海岛基础地理信息获取、地质灾害识别和生态环境修复提供基础数据支撑。     

导线测量中全站仪棱镜常数的影响

针对导线测量中棱镜常数设置错误的情况,分析了导线验算无法检核棱镜常数使用错误的原因,研究了棱镜常数使用错误对平差结果的影响,提出了导线测量中棱镜常数使用是否正确的检测方法,通过使用该方法可以避免距离测量的粗差,从而保证导线测量的精度。     

南海岛礁航空摄影常见问题及对策

为解决远离大陆的海岛礁地形测绘的技术难题,在西沙群岛应用IMU/DGPS辅助海岛礁无控航空摄影技术进行了作业,经实测成果检验,影像精度满足大比例尺航测要求。基于试验分析,对在南海岛礁进行航空摄影常见问题提出了解决建议,有助于航空摄影测量技术在海岛礁测绘中的应用推广。     

A numerical study of the relative importance of wind and topographic forcing on oceanic eddy shedding by tall, deep water islands

A process-oriented, quasi-geostrophic, barotropic model has been developed with the aim of studying the relative importance of wind and topographic forcing on oceanic eddy generation by tall, deep water islands. As a case study, we chose the island of Gran Canaria. Topographic forcing was established using different intensities (weak, medium, strong, and very strong) for the oceanic current incident to the island. Wind forcing was introduced to simulate the mean wind curl observed in atmospheric tall island wakes. As observed from in situ data, the resulting wind curl consists of two cells of opposite sign which become a complementary source of vorticity at the island lee. The intensity and the shape of the two cells depend on the strength of the incident wind against the obstacle. The oceanic model was forced at three different wind (trade winds) speeds which correspond to weak, medium and strong wind intensities. Results from several numerical experiments show that in those periods where the incident wind is in the medium–strong range and the incident current speed is low (low Reynolds number), the wind forcing is the trigger mechanism for oceanic eddy generation. Eddies are spun off from the island for a lower Reynolds number (Re)/intensity of the oceanic flow (Re = 20) when compared with only topographic forcing (Re > 60). However, when the current speed is strong (high Reynolds number), the vorticity input by the wind is quickly advected by the oceanic flow and does not contribute to oceanic eddy generation. When only wind forcing is considered, only two stationary eddies are generated in the island wake. In this case, eddies of opposite sign are not sequentially spun off by the island and a Von-Kármán-like eddy street is not developed downstream of the island. Therefore, the main mechanism responsible for the development of an eddy street is the topographic perturbation of the oceanic flow by the island flanks. The wind over the island wake acts only as an additional source of vorticity, promoting the generation of an eddy street at a lower intensity of the incident oceanic flow, but not being capable of generating an eddy street without the topographic forcing.     

上海市滩涂水下地形测量研究

针对上海市滩涂水下地形测量工作的历史与现状,详细介绍了滩涂水下地形的测量方法、技术标准以及测绘成果的应用,说明了水下地形测量工作在水利事业中发挥的重要作用,并对更好地提高测绘精度提出了建议,展望了滩涂水下地形测绘的未来发展。     

强潮河口水下地形测量潮位控制研究

钱塘江河口属于强潮河口,具有潮差大、流急、地形复杂和局地潮汐变化大等特点,对潮位控制设计与实施造成较大困难。为解决钱塘江河口水下地形测量潮位控制难题,针对强潮河口的水下地形和潮汐特征进行分析,提出了该区域潮位控制的潮位站布设方案与作业时间要求。实测数据表明,只要合理布设潮位站、选择合适的时间段作业,强潮河口水下地形测量的潮位控制可以达到规范精度要求。     

Variations in the thermal conductivities of surface sediments in the Nankai subduction zone off Tokai, central Japan

We investigated the relationship between variations in the thermal conductivity of surface sediments and the topography in the Nankai subduction zone off Tokai, central Japan, the easternmost part of the Nankai subduction zone, which has an accretionary prism with varied topography. We analyzed sediment thermal conductivity data obtained from the trough floor and accretionary prism. Variations in the thermal conductivity of sediments were related to the topographic features formed by accretionary prism development. Thermal conductivities of 1.1?W/m?K were measured on the trough floor where thick terrigenous turbidites have been deposited. The thermal conductivity of Nankai Trough floor sediments decreases from northeast to southwest along the trough, probably because of the decreased grain size and/or changes in sediment mineral composition. High thermal conductivities (??1.0?W/m?K) were measured in fault scarps on the accretionary prism. A landward increase in these values on the prism may be explained by decreased porosity of the sediments attributable to tectonic deformation during accretionary prism development. At the base of the fault scarp of the frontal thrust, low thermal conductivities (<0.9?W/m?K) were measured, likely reflecting the high porosity of the talus deposits. Low thermal conductivity (0.9?W/m?K) was also measured in slope basins on the accretionary prism, likely also related to the high porosity of the sediments. Our results demonstrate that, for accurate heat flow measurement in an area of varied topography, the geothermal gradient and the thermal conductivity of the sediments must be measured within regions with similar topographic features.     

多波束测深边缘波束误差的综合校正

边缘波束误差是影响多波束测深数据精度的主要因素,数据精度影响其可信度和使用范围,也是进行相关研究的基础.多波束勘测系统声呐参数的精确校正、勘测区声场模型的建立以及实时勘测海洋噪声的合理剔除是影响边缘波束数据质量的关键因素,严重时甚至导致勘测数据出现沿测线方向的条带状假地形或地形位置偏移.上述因素对多波束勘测数据的影响是一个综合作用的过程,靠单一的校正或编辑方法很难提高采集数据的精度.以多波束勘测原理和声学理论为指导,以多波束实测数据为研究基础和分析对象,运用GIS面向对象方法,全面分析造成多波束勘测大误差边缘波束的原因,并探寻改善已勘测多波束大误差数据、提高数据精度的综合处理方法,最终以可视化的方式实现人机交互处理.该项研究成果已初步应用于海洋项目总图编绘工作,并取得了预期效果.