A new method for absolute datum transfer in seafloor control network measurement

Abstract

To decrease the time consumption and the labor intensity in the absolute datum transfer of traditional seafloor control network measurement, a new method, namely sailing-circle positioning method, is put forward in this paper. First, the traditional intersection positioning model is improved by considering the equivalent sound velocity profile error as an unknown parameter in the adjustment model. Second, the effect of geometric dilution of precision (GDOP) on positioning accuracy is analyzed. By seeking for the minimum of GDOP, it is concluded that the absolute datum transfer can achieve the highest accuracy in the condition of sailing along a circle relative to other sailing paths. Moreover, the optimal radius of the circle for the accurate datum transfer is also given out. Besides, the correlation between the accuracy of datum transfer and the sound velocity error in this method is analyzed. Finally, the new method was tested and verified by the experiments in Songhua lake with the water depth of 60 m and in South China sea with the water depth of 2000 m, respectively. These experiment results show that the new method can improve the accuracy and efficiency of traditional datum transfer method significantly.

Adjustment of Transceiver Lever Arm Offset and Sound Speed Bias for GNSS-Acoustic Positioning

“…Although the research of the virtual station is useful for the determination of the plate motion, which meets the needs of the geodetic survey, it is not specific to the precise position of each entity transponders; thus, its results are hard to be directly used in engineering construction and marine environment monitoring. Some scholars studied the positioning technology of the seafloor entity station composed of a single acoustic transponder, and proposed methods of optimising sailing tracks, processing methods of measurement differencing, and using distances between seafloor stations to build an adjustment model [28][29][30], which reduces the temporal and spatial correlation error and improves the positioning precision. However, few studies specifically discuss the systematic biases of the velocity of sound, including sound velocity measurement errors and temporal and spatial changes.…”

Random Optimization Algorithm on GNSS Monitoring Stations Selection for Ultra‐Rapid Orbit Determination and Real‐Time Satellite Clock Offset Estimation

“…In the three-dimensional case, in the center of the regular polyhedron, Cartesian configuration, spiral configuration, Walker configuration, and any combination of them, the GDOPs are minimal [15], and five types of regular polyhedral, including regular tetrahedrons, cubes, regular octahedrons, icosahedrons, and regular dodecahedrons, can be derived. Conical structures have been used for underwater positioning to control the course of ships [16,17]. Even so, it is still difficult to find all configurations with the lowest GDOP, furthermore, any theoretically optimal configuration cannot be directly applied to the actual situations, such as the distribution constrains of ground stations and the 71% ocean limitation.…”

Localization of an Underwater Control Network Based on Quasi-Stable Adjustment

“…It uses one survey vessel around one unknown point for circular sailing. Relative to the GPS-acoustic method, the circle navigation incident angle of the measuring beam is approximately equal, as well as the ranging error brought by velocity, which can be effectively eliminated after the least squares solution [ 14 , 15 ]. However, when there are many points to be determined in an underwater control network, circle navigation becomes time consuming and laborious.…”