Research On Key Technologies Of Calibration For Long Baseline Navigation System Array Position

At present,underwater acoustic positioning system has been widely used in ocean development,ocean monitoring,underwater exploration,submarine oil and gas pipeline laying,submarine archaeology and other fields.As one of the commonly used underwater positioning systems,long baseline system is guaranteed by its array position calibration.The research of array position calibration technology has strong practical application value.Based on several problems of element position calibration for long baseline system,a series of studies have been carried out in this paper.The main contents of this paper include the following aspects:1.The shortcomings of previous models of element position calibration are described.Two classical models of element position calibration are introduced.The reasons that affect the calibration accuracy of traditional models are obtained through theoretical analysis,and an optimization model is put forward.In order to make better use of the redundant data in the measurement process,the differential evolution algorithm is used to solve the model.The influence of measure errors on the calibration accuracy of the optimization model is analyzed,and the performance of the traditional model and the optimization model in element position calibration is simulated and compared.The results show that the optimization model has high calibration accuracy and can be better adapted to the maneuvering calibration of measuring ships.2.The influence of sound field on sound line bending is analyzed,and the sound field model is built based on Bellhop.The effective sound velocity is used as the element position calibration solution to compensate the acoustic field.The difference of the calibration accuracy before and after compensation is compared by simulation,which verifies the necessity of the acoustic field compensation.3.The relationship between the layout of calibration measurement points and the calibration accuracy is analyzed,and the calibration radius is optimized with the cramer-rao lower bound of time delay estimation,which provides theoretical support for determining the baseline length of calibration route.The difference of calibration accuracy between the three traditional routes and the designed routes in this paper is compared by simulation.The results show that the designed routes have high calibration accuracy and can be used in actual calibration work.4.Based on the actual sea trial,the processing of array position calibration delay signal is carried out,and an effective sonic tachometer is established by using the measured hydrological information.The array position of a long baseline system is calibrated by the time delay obtained from sea trial and the GPS position information of the surveying ship.The results of long baseline positioning show that the long baseline system has been well calibrated.In this paper,several problems of element position calibration for long baseline system are studied.The results show that the calibration model established in this paper has high calibration accuracy,which opens a good foundation for the follow-up work.