AUV水下移动重力测量建模及误差分析

Modeling and Error Analysis of AUV Underwater Mobile Gravimetry

摘要:

水下移动重力测量能够连续实施近水底的重力勘测，如使用自主水下无人航行器(AUV)还能允许水面母船同时执行多个任务，进而降低水下重力测量相关的高昂成本和准入门槛。研究了水下移动重力测量的基本原理和方法，建立了水下移动重力测量模型和相应的误差模型，重点分析了捷联式重力仪的传感器、姿态、位置、速度等误差源。讨论了达到 1 mgal 测量精度的可行性以及对水下定位设备的性能要求。 经计算，在重力传感器与捷联式航空重力仪一致，水声定位系统定位精度达到测量斜距的 0.5%，水压深度计测深测量精度达到 5 cm，多普勒计程仪测速精度达到 0.1 m/s 的情况下，可以确保水下移动重力测量达到精度要求。

Abstract:

Gravity survey near the bottom can be continuously carried out in underwater mobile gravimetry， such as using autonomous underwater vehicle(AUV)to allow the surface mother ship to perform multiple tasks Simultaneously，and thus reducing the high cost and access threshold of underwater gravity survey. In this paper，the basic principles and methods of underwater mobile gravimetry are studied，the underwater mobile gravimetry model and the corresponding error model are established，and the error sources of sensor，attitude，position and velocity of Strapdown gravimeter are analyzed emphatically. The feasibility of reaching 1 mgal measurement accuracy and the performance requirements of underwater positioning equipment are discussed. The calculation shows that on the premise that the gravity sensor and the Strapdown gravimeter are consistent，the positioning accuracy of the underwater acoustic positioning system can reach 0.5% of the measured slant distance，the sounding accuracy of the water pressure depth meter can reach 5 cm，and the velocity accuracy of the Doppler log can reach 0.1 m/s，which can ensure that the underwater mobile gravimetry meets the accuracy requirements.