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A Symbol-Based Passband Doppler Tracking and Compensation Algorithm for Underwater Acoustic DSSS Communications

Journal of Communications and Information Networks 2020年第2期5卷 168-176页

作者： dajun sun Xiaoping Hong Hongyu Cui Lu Liu College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China Acoustic Science and Technology Laboratory Harbin Engineering UniversityHarbin 150001China Key Laboratory of Marine Information Acquisition and Security(HEU) Ministry of Industry and Information TechnologyHarbin 150001China

In this paper,we consider the problem of Doppler tracking and compensation for a direct sequence spread spectrum(DSSS)signal in underwater acoustic(UWA)*** the dynamic property of the UWA channel and the long duration of DSSS signals result in significant Doppler spread that severely distorts the propagated signal,Doppler tracking and compensation are *** on the ultra-wideband property of UWA signal,the Doppler spread not only results in the frequency shift,but also changes the signal ***,the accurate estimation of the signal expansion/compression in the time domain can reflect the Doppler ***,we present a Doppler tracking and compensation algorithm for a DSSS signal operating on the correlation output of passband signal at a symbol-by-symbol *** that the carrier frequency of UWA communication is around several kilohertz,and thus the time delay estimation can be performed on the passband to improve the ***,the prior information of Doppler limit is used to refine the resolution of delay estimation and achieve sequential *** compensate the correlation magnitude distortion induced by the velocity variation,the local reference signal is selected adaptively based on the filtered Doppler *** results demonstrate that the proposed passband Doppler tracking algorithm achieves a superior performance compared with the conventional receiver.

关键词： UWA communications DSSS passband Doppler tracking and compensation three-point interpolation

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A Block Parallel l_0-Norm Penalized Shrinkage and Widely Linear Affine Projection Algorithm for Adaptive Filter

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China Communications 2017年第1期14卷 86-97页

作者： Youwen Zhang Shuang Xiao Lu Liu dajun sun Acoustic Science and Technology Laboratory Harbin Engineering University Harbin 150001 China College of Underwater Acoustic Engineering Harbin Engineering University Harbin 150001 China

To improve the identification capability of AP algorithm in time-varying sparse system, we propose a block parallel l_0-SWL-DCD-AP algorithm in this paper. In the proposed algorithm, we first introduce the l_0-norm constraint to promote its application for sparse system. Second, we use the shrinkage denoising method to improve its track ability. Third, we adopt the widely linear processing to take advantage of the non-circular properties of communication signals. Last, to reduce the high computational complexity and make it easy to implemented, we utilize the dichotomous coordinate descent(DCD) iterations and the parallel processing to deal with the tapweight update in the proposed algorithm. To verify the convergence condition of the proposed algorithm, we also analyze its steadystate behavior. Several simulation are done and results show that the proposed algorithm can achieve a faster convergence speed and a lower steady-state misalignment than similar APA-type algorithm. When apply the proposed algorithm in the decision feedback equalizer(DFE), the bite error rate(BER) decreases obviously.

关键词： signal processing adaptive algorithm LMS l0-norm shrinkage linear DCD

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Improvement of Seafloor Positioning Through Correction of Sound Speed Profile Temporal Variation

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IEEE/CAA Journal of Automatica Sinica 2023年第4期10卷 1099-1101页

作者： Miao Yu Kuijie Cai Cuie Zheng dajun sun Acoustic Science and Technology Laboratory Harbin Engineering UniversityHarbin 150001 Key Laboratory of Marine Information Acquisition and Security(Harbin Engineering University) Ministry of Industry and Information TechnologyHarbin 150001 College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China College of Mathematical Sciences Harbin Engineering UniversityHarbin 150001China

Dear Editor,This letter proposes a high-precision seafloor transponder positioning method based on the correction of sound speed profile(SSP)temporal *** the proposed method,the ocean sound speed error is modeled as the temporal variation of a background SSP,and the linearized expression of the acoustic travel time with respect to the sound speed coefficient is derived based on the ray acoustic ***,the proposed method introduces the constraint of acoustic ranging observations between seafloor transponders and determines the weights of travel time and ranging observations using Akaike’s Bayesian information criterion(ABIC)to reduce the positioning error caused by the correlation between sound speed and position *** experimental results in the South China Sea show that the proposed method performs better than the global navigation satellite system-acoustic ranging combined positioning solver(GARPOS)[1],in terms of rigid distance errors and long baseline positioning accuracy.

关键词： ocean travel sound

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Seafloor geodetic network establishment and key technologies

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Science China Earth Sciences 2020年第8期63卷 1188-1198页

作者： Yuanxi YANG Yanxiong LIU dajun sun Tianhe XU Shuqiang XUE Yunfeng HAN Anmin ZENG State Key L aboratory of Geo-Information Engineering Xi'an Research Institute of Surveying and MappingXi'an 710054China First Institute of Oceanography Ministry of Natural ResourceQingdao 266061China College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China Institute of Space Sciences Shandong UniversityWeihai 264209China Chinese Academy of Surveying and Mapping Beijing 100830China

Seafloor geodetic network construction involves the development of geodetic station shelter, network configuration design, location selection and layout, surveying strategy, observation model establishment and optimization, data processing strategy and so on. This paper tries to present main technological problems involved in the seafloor geodetic network construction, and seek the technically feasible solutions. Basic conceptions of developing seafloor geodetic station shelters for shallow sea and deep-sea are described respectively. The overall criteria of seafloor geodetic network construction for submarine navigation and those of network design for crustal motion monitoring are both proposed. In order to enhance application performances of the seafloor geodetic network, the seafloor network configuration should prefer a symmetrical network structure. The sea surface tracking line measurements for determining the seafloor geodetic station position should also adopt an approximately symmetrical configuration, and we recommend circle tracking line observations combined with cross-shaped line(or double cross-shape line) observations for the seafloor positioning mode. As to the offset correction between the Global Navigation Satellite System antenna phase center and the acoustic transducer, it is recommended to combine the calibration through external measurements and model parameter estimation. Besides, it is suggested to correct the sound speed error with a combination of observation value correction and parameterized model correction, and to mainly use the model correction to reduce the influence of acoustic ray error on the seafloor positioning. Following the proposed basic designs, experiments are performed in shallow sea area and deep-sea area respectively. Based on the developed seafloor geodetic shelter and sufficient verification in the shallow sea experiment, a long-term seafloor geodetic station in the deep-sea area of 3000 m depth was established for the

关键词： Seafloor geodesy Seafloor geodetic network Seafloor shelter Undersea navigation Acoustic positioning

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High-resolution topography measurement of PACMANUS and DESMOS hydrothermal fields using a ROV in Manus basin

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Science Bulletin 2016年第15期61卷 1154-1156页

作者： Xiaochuan Ma Jun Yan Zhendong Luan Xin Zhang Cui-E Zheng dajun sun Institute of Oceanology Chinese Academy of Sciences KeyLaboratory of Marine Geology and EnvironmentQingdao 266071 China Harbin Engineering University Ringgold Standard Institution College of Underwater Acoustic Engineering Harbin 150001China

In China,the lack of high-resolution topographical data from small target areas limits our understanding of deep sea ***,the high-resolution topography of the PACMANUS hydrothermal field and the DESMOS hydrothermal field were measured using a remotely operated underwater vehicle(ROV)with a multibeam system.A composition positioning system on the ROV provided high positioning accuracy(greater than 0.5 m).The data show that four knolls develop in the PACMANUS field on the crest of the Pual ***

关键词：高分辨率地形测量 ROV 热场海盆组合定位系统目标区域多波束系统

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Crosslinked hydrogels--a promising class of insoluble solid molecular dispersion carriers for enhancing the delivery of poorly soluble drugs

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Acta Pharmaceutica Sinica B 2014年第1期4卷 26-36页

作者： dajun D.sun Ping I.Lee Department of Pharmaceutical Sciences Leslie Dan Faculty of PharmacyUniversity of TorontoToronto M5S 3M2OntarioCanada

Water-insoluble materials containing amorphous solid dispersions(ASD)are an emerging category of drug carriers which can effectively improve dissolution kinetics and kinetic solubility of poorly soluble *** based on water-insoluble crosslinked hydrogels have unique features in contrast to those based on conventional water-soluble and water-insoluble *** example,solid molecular dispersions of poorly soluble drugs in poly(2-hydroxyethyl methacrylate)(PHEMA)can maintain a high level of supersaturation over a prolonged period of time via a feedback-controlled diffusion mechanism thus avoiding the initial surge of supersaturation followed by a sharp decline in drug concentration typically encountered with ASDs based on water-soluble *** creation of both immediate-and controlled-release ASD dosage forms is also achievable with the PHEMA based *** far,ASD systems based on glassy PHEMA have been shown to be very effective in retarding precipitation of amorphous drugs in the solid state to achieve a robust physical *** review summarizes recent research efforts in investigating the potential of developing crosslinked PHEMA hydrogels as a promising alternative to conventional water-soluble ASD carriers,and a related finding that the rate of supersaturation generation does affect the kinetic solubility profiles implications to hydrogel based ASDs.

关键词： Amorphous solid dispersions Crosslinked hydrogels Poly(2-hydroxyethylmethacrylate) Supersaturation Kinetic solubility

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Study on the influence of the subsurface buoy＇s vibration on the vector sensor due to ocean current

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High Technology Letters 2014年第3期20卷 223-229页

作者：师俊杰 sun dajun Lv Yunfei Lan Hualin Mei Jidan Key Laboratory of Underwater Acoustic Technology Underwater Acoustic Engineering College HarBin Engineering University Harbin 150001 P. R. China

Subsurface buoy systems,especially equipped with the vector sensor,have more and more extensive applications in military and civilian ***,their acoustic performances are constrained by the vibration resulting from the unavoidable ocean current in some *** influence of such vibrations is quantitatively analyzed by means of modeling the simplified models of two deployment configurations involving the positive buoyant buoy and neutral buoy *** corresponding formulas are deduced respectively for the deployment configuration buoy systems in the motion state *** the simulation software is developed and some numerical simulations are put up via the Runge-Kutta *** simulation results and theoretical analysis indicate that the neutral buoy will be an excellent design protocol in engineering application in comparison with the positive buoyant buoy.

关键词： subsurface buoy system vector sensor ocean current neutral buoy

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Rapid calibration method for rank defect marine geodetic station network

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Chinese Journal of Acoustics 2023年第4期42卷 434-449页

作者： sun dajun OUYANG Yujie HAN Yunfeng National Key Laboratory of Underwater Acoustic Technology Harbin Engineering UniversityHarbin 150001 Key Laboratory of marine Information Acquisition and Security(Harbin Engineering University) Ministry of Industry and Information TechnologyHarbin 150001 College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001

A rapid calibration method for marine geodetic control networks based on the combination of beacon mutual ranging information and absolute coordinate information is *** with existing methods, the rapid calibration method reduces the initial condition restriction of free net adjustment, the number of absolute calibration points is reduced by more than 50%, and the calibration efficiency and absolute coordinate precision are significantly improved. In addition, several typical formations under ideal conditions are proposed by analyzing the formations and absolute calibration points. The shallow water test results show that the calibration efficiency is improved by 50% when the calibration precision of the reference network is greater than 0.2 m.

关键词： formations marine shallow

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A high precision calibration method for long baseline acoustic positioning systems

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Chinese Journal of Acoustics 2017年第4期36卷 489-500页

作者： HAN Yunfeng ZHENG Cuie sun dajun Acoustic Science and Technology LaboratoryHarbin Engineering University College of Underwater Acoustic Engineering Harbin Engineering University

To solve the problem that traditional long baseline（LBL） positioning system is easily affected by severe sound speed varying results in low calibration precision, low efficiency and inconsistent position using different references, we propose a high precision array calibration method. We use distances between beacons to build error adjustment model. This model improves the calibration performance of traditional calibration method. The theory shows this method can achieve equal calibration precision with distance measurement precision in horizon. This method can improve the calibration efficiency, solve position ambiguity and achieve high precision especially in deep ocean. The shallow water experiment shows this method has millimeter calibration precision which is equal to distance measurement error. The calibration precision improves from centimeter to millimeter compared to traditional calibration *** method also decreases the operation complexity. The localized positions are more close to GPS compared to traditional method, which has great application values.

关键词： calibration positioning beacon underwater adjustment shallow baseline coordinate trajectory positions

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High resolution underwater acoustic image measurement method based on deconvolution

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Chinese Journal of Acoustics 2020年第4期39卷 433-453页

作者： MEI Jidan PEI Yuqing sun dajun SHI Wenpei Acoustic Science and Technology Laboratory Harbin Engineering UniversityHarbin 150001 Key Laboratory of Marine Information Acquisition and Security(Harbin Engineering Uninersity) Ministry of Industry and Infornation TechrologyHarbin 150001 College of Underuwater Acoustic Engincering Harbin Engineering UniversityHarbin 150001

In order to improve the resolution and positioning accuracy of multiple sound sources in acoustic image measurement,a near-field deconvolution focus beamforming acoustic image measurement method is *** near-field two-dimensional generalized convolution mathematical model is *** is among the conventional acoustic image measurement results,the *** function,and the array directivity *** point spread function is shift-variant in the acoustic image measurement,but it is *** beamforming can be achieved by convolution *** the convolution operation can be translated into the original superposition integral problem by the pre-storing point spread function ***-Lucy iterative algorithm has the ability of *** the near-field acoustic image deconvolution problem,a two-dimensional algorithm is adopted,and the high-resolution acoustic image measurement processing is *** performance of deconvolution,conventional and MVDR acoustic image measurement is compared by simulation and sea *** results show that the focus peak size of the proposed algorithm is less than 1/2 of the other two algorithms when the RL algorithm in 500 *** side lobe level drops by more than 6 dB.

关键词： image resolution algorithm

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