Study On Algorithm Of Precise Marine Geodetic Datum Positioning And Long Baseline Underwater Acoustic Navigation

The ocean is rich in resources.With the implementation of China’s strategy of building an ocean power,various types of marine resource development work have emerged,and these work require the support of high-precision,high-reliability marine geodetic datum and underwater navigation technology.Based on the above requirements,this paper systematically studies marine geodetic datum positioning and long baseline underwater acoustic navigation algorithm.The main contents are as follows:(1)Aiming at the problem that the positioning accuracy of the marine geodetic datum is reduced due to the measurement error of the lever arm,a single marine geodetic datum positioning model based on the lever arm correction and a marine geodetic datum network positioning model based on the lever arm correction are constructed in this paper.The above two models set the lever arm as the model parameter,and estimate the lever arm through single point solution and network solution respectively,so as to reduce the calibration error caused by the lever arm measurement error.Through the experiment,compared with the traditional marine geodetic datum positioning model,the external coincidence accuracy of the single marine geodetic datum positioning model based on the lever arm correction is increased by 35.18%,and the internal coincidence accuracy is increased by 34.13%,the external coincidence accuracy of the marine geodetic datum network positioning model based on the lever arm correction is increased by 57.57 %,and the internal coincidence accuracy is increased by37.37 %.The experimental results show that the single marine geodetic datum positioning model and the marine geodetic datum network positioning model based on the lever arm correction can effectively estimate and correct the lever arm measurement error,so as to improve the positioning accuracy of marine geodetic datum.(2)Aiming at the problem that the positioning accuracy of marine geodetic datum is reduced due to the Doppler frequency shift error,this paper construct a marine geodetic datum positioning model based on Doppler frequency shift error correction.The model constructs a Doppler frequency shift compensation parameters according to the character of Doppler frequency shift error,and uses this parameter to modify the range observation value,thus reducing the positioning error caused by Doppler frequency shift error.Through experiments,compared with the traditional marine geodetic datum positioning model,the external coincidence accuracy of the marine geodetic datum positioning model based on Doppler frequency shift error correction is increased by 31.87%,and the internal coincidence accuracy is increased by 18.33%.The experimental results show that the marine geodetic datum positioning model based on Doppler frequency shift error correction can effectively estimate and correct the Doppler frequency shift error,thereby improving the positioning accuracy of marine geodetic datum.(3)Aiming at the problem that the variation of sound velocity during positioning the marine geodetic datum,this paper proposes a marine geodetic datum positioning algorithm based on twice time-varying sound velocity error estimation.The algorithm first uses two cubic B-spline curves with different smoothness to parameterize the long-period and short-period terms of the sound velocity error,and then constructs an observation model containing two sets of sound velocity correction parameters.Finally,the model is solved by the maximum posteriori estimation.Under the experimental condition of 3000 m water depth,the standard deviation of the average one-way slant range error of the marine geodetic datum positioning algorithm based on twice time-varying sound velocity error estimation reaches 13 cm,and the difference between the positioning results of the two data sets reaches 17.1cm.The experimental results show that marine geodetic datum positioning algorithm based on twice time-varying sound velocity error estimation significantly improves the positioning accuracy of marine geodetic datum.(4)Aiming at the problem that the changeable motion state of underwater vehicle and abnormal observations in long baseline underwater acoustic navigation,this paper proposes a long baseline underwater acoustic navigation algorithm based on improved robust interacting multiple model.The algorithm construct a mixed equivalent variance,and correct the model probability.By processing simulation and measured data,it can be obtained that,compared with Kalman filter,interacting multiple model and robust interacting multiple model,the navigation accuracy of this method is improved by 68.70 %,10.41 % and 12.63 % respectively when the simulation data does not contain gross errors,and the navigation errors of this method are reduced by 64.18 %,26.35 % and 10.61 % respectively when the simulation data contains gross errors,the measured data results show that the navigation accuracy of the proposed method is improved by 31.79 %,14.76 % and 14.93 % respectively.The experimental results show that compared with the traditional filtering algorithm,the improved robust interacting multiple model algorithm can significantly improve the navigation accuracy and stability of the underwater vehicle.