共查询到19条相似文献，搜索用时 93 毫秒
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针对远离大陆的海岛礁地形测绘与高程基准转换困难的问题,基于ADS40航摄系统获取远离大陆的海岛礁区域遥感影像,按照GPS差分无地面控制点的空中三角测量模式实现海岛礁的地理定位,选择高精度的卫星测高模型实现海岛礁区域的高程基准转换。在某海域进行了ADS40测量作业与高程基准转换试验,结果表明,无地面控制点空中三角测量的平面精度达到0.587m;基于卫星测高模型进行垂直基准转换的精度与同步验潮水位观测法得到的高程传递精度相当。 相似文献
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远离岸线的中距离(30~50 km)海域缺少测绘基础资料,高程传递尚未形成相应的作业体系。为满足海上工程建设的精度要求,采用同步验潮平均海面传递法、GNSS/水准传递法以及DTU18全球平均海面模型传递法,在山东省半封闭海域与开阔海域进行了中距离海上高程传递实验。实验结果表明,15天同步验潮平均海面传递法与GNSS/水准法的精度相当(厘米级),与DTU18全球平均海面模型传递法进行直接传递的差异在15 cm内,可为不同测绘基础条件下海上风电高程基准传递提供作业参考。 相似文献
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Route height connection across the sea by using the vertical deflections and ellipsoidal height data
Distance between the main land and island is so long that it is very difficult to precisely connect the height datum across the sea with the traditional method like the trigonometric leveling,or it is very expensive and takes long time to implement the height transfer with the geopotential technique.We combine the data of GPS surveying,astro-geodesy and EGM2008 to precisely connect the orthometric height across the sea with the improved astronomical leveling method in the paper.The Qiongzhou Strait is selected as the test area for the height connection over the sea.We precisely determine the geodetic latitudes,longitudes,heights and deflections of the vertical for four points on both sides across the strait.Modeled deflections of the vertical along the height connecting routes over the sea are determined with EGM2008 model based on the geodetic positions and heights of the sea segmentation points from DNSC08MSS model.Differences of the measured and modeled deflections of the vertical are calculated at four points on both sides and linearly change along the route.So the deflections of the vertical along the route over the sea can be improved by the linear interpolation model.The results are also in accord with those of trigonometirc levelings.The practical case shows that we can precisely connect the orthometric height across the Qiongzhou Strait to satisfy the requirement of order 3 leveling network of China.The method is very efficient to precisely connect the height datum across the sea along the route up to 80 km. 相似文献
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Height datum is an important part of national geodetic network. Establishment of a unified national land and sea elevation benchmarks and implementation of height datum connection between the Chinese mainland and offshore islands are issues that need to be resolved in geomatics and marine sciences. Derived from basic definition of elevation datum and relationship between geo-potential and normal height, the scientific theory and algorithm for transferring height datum from mainland to islands with geo-potential are elaborated. The accuracy of geo-potential difference is discussed using a numerical analysis method. We also give criteria to choose virtual leveling routines and algorithm to give optimized results. One experiment in the China seas, among 26 tidal gauge stations in the sea coast of the mainland with known normal height, has confirmed the reliability and accuracy of the method developed in this paper. Further optimizations for improving accuracy of island elevation are also introduced. Distribution of quasi-geoid near Xisha Islands is also given with this method. 相似文献
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High precision geoid models HKGEOID-2000 for Hong Kong and SZGEOID-2000 for Shenzhen, China, have been developed with a hybrid approach of so-called sequential processing, using high precision GPS/leveling data, land and sea gravity anomalies, and digital terrain models. These two local geoid models have the same 1-km resolution. The estimated accuracy (external accuracy) is better than 1.7 cm for HKGEOID-2000 and 1.4 cm for SZGEOID-2000. Some common areas are covered by HKGEOID-2000 and SZGEOID-2000. So these two geoid models, along with high quality GPS/leveling data collected on the overlapping areas, can be used to detect the systematic bias between HKGEOID-2000 and SZGEOID-2000, as well as the difference between Hong Kong Principal Datum and 1956 yellow sea height datum of China, yielding RMS errors of 1.011 m and 1,003 m, respectively. Moreover, HKGEOID-2000, along with GPS ellipsoidal heights, is employed to determine the errors of the “orthometric heights” from purely trigonometric heighting, yielding an RMS error of 0.102 m. The combination of SZGEOID-2000 and GPS ellipsoidal heights has been used to replace the traditional spirit leveling and mapping, called GPS mapping. 相似文献
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High precision geoid models HKGEOID-2000 for Hong Kong and SZGEOID-2000 for Shenzhen, China, have been developed with a hybrid approach of so-called sequential processing, using high precision GPS/leveling data, land and sea gravity anomalies, and digital terrain models. These two local geoid models have the same 1-km resolution. The estimated accuracy (external accuracy) is better than 1.7 cm for HKGEOID-2000 and 1.4 cm for SZGEOID-2000. Some common areas are covered by HKGEOID-2000 and SZGEOID-2000. So these two geoid models, along with high quality GPS/leveling data collected on the overlapping areas, can be used to detect the systematic bias between HKGEOID-2000 and SZGEOID-2000, as well as the difference between Hong Kong Principal Datum and 1956 yellow sea height datum of China, yielding RMS errors of 1.011 m and 1,003 m, respectively. Moreover, HKGEOID-2000, along with GPS ellipsoidal heights, is employed to determine the errors of the “orthometric heights” from purely trigonometric heighting, yielding an RMS error of 0.102 m. The combination of SZGEOID-2000 and GPS ellipsoidal heights has been used to replace the traditional spirit leveling and mapping, called GPS mapping. 相似文献
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通过对福建沿岸多年来已有的当地平均海面高程资料和与1985国家高程基准的水准点联测成果，分析并研究了福建沿岸主要验潮站的当地平均海面的高程情况和变化趋势，对福建沿岸当地平均海面的高程（1985国家高程基准）进行了比较深入的研究和探讨，阐述了福建沿岸与浙江、广东沿海平均海面高程的连续性和与我国海区平均海面高程的一致性，论述了当地平均海面高程的应用方法，以解决福建沿海海岸地形图和水深图的基准统一及高度衔接问题。 相似文献
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Jinyun Guo Xin Liu Yongning Chen Jianbo Wang Chengming Li 《Marine Geophysical Researches》2014,35(2):141-148
Heights as the basic geographical information are very important to study marine geophysics, geodesy and oceanography. Based on the astronomical leveling principle, we put forward a new method to unify the normal height (NH) datum along one ship route across sea with the ship-borne gravimetry and global navigation satellite system (GNSS) techniques. Ship-borne gravimeter can precisely measure gravity anomalies and the GNSS technique is used to measure precise sea surface heights (SSHs) along the ship track across sea. Precisions of ship-borne gravities and SSHs are improved with the colinear adjustment. To remove the effects of sea wave and wind, the Gaussian filter is used to filter residuals both between the ship-borne and modeled gravities from EGM2008 to degree 2160, and the measured and modeled SSHs from DTM10MSS, respectively. Deflections of the vertical (DOVs) along the ship route are estimated from the measured gravities with the least squares collocation method. The astro-geodetic survey is made on continent and island to improve the accuracy of DOVs along the route. We use the new method to connect NHs on the coastal sea of Shandong Peninsula, China. The results indicate that the method is very efficient to precisely connect the NH along the ship route across sea. 相似文献
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在海洋测深中，由于波浪和潮汐的影响，调查船或无人船所测量的瞬时水深不能直接作为海图水深。本文提出了一种新型的无人船海洋水深测量技术，以评估搭载RTK和单波束测深仪的无人船用于海洋水深测量的潜能。首先，使用无人船所搭载RTK的厘米级精度高程数据，通过低通滤波剔除波浪信息，而获得海平面高程。然后，基于潮汐表和无人船海平面高程，构建了一种参考椭球面和海图的两个基准面之差的获取方法；在常规的海洋调查中，该基准面差通常需要由长期的验潮获得。最后，利用海图基准和无人船测量的瞬时水深的转换关系，计算出海图水深。在海南省蜈支洲岛周边海域，利用自研发的无人船“USBV”开展了相关海上实验，以验证所提出的技术方法。实验结果验证了该无人船海洋水深测量技术。 相似文献