GNSS多天线基线网单历元模糊度同步解算法     

汤佳明  柴艳菊  闻德保  欧吉坤 《大地测量与地球动力学》2019,39(3):262-268

提出多天线基线网单历元模糊度同步解算法，其具体实现步骤为：1）根据宽巷组合模糊度易于固定的优点，采用附加已知基线长度约束法同步解算各基线的宽巷模糊度，得到dm~cm级精度的近似基线分量；2）将解算得到的各近似基线分量作为约束，同步解算各基线的基频模糊度，以获取mm级精度的基线矢量。该方法的关键在于检验各历元宽巷模糊度解算的正确性，以获取可靠的近似基线分量，为解算各基线的基频模糊度提供准确的基线先验信息。由于动态情况下各历元观测信息比较少，单纯依赖ratio检验不可靠，提出结合基线误差、单位权中误差、基线网模糊度闭合环及ratio值等对多组宽巷模糊度进行检验，避免ratio值设置不当导致模糊度检验中发生纳伪和弃真问题。实测数据结果证明，该处理方法使得模糊度解算的成功率提高1%~2%，可以获取移动平台更丰富的导航信息，提高其服务能力。  相似文献   

Reduction of hydroelastic responses of a very-long floating structure by a floating oscillating-water-column breakwater system     

D.C. Hong  S.Y. Hong  S.W. Hong 《Ocean Engineering》2006,33(5-6):610-634

The hydroelastic responses of a very-long floating structure (VLFS) placed behind a reverse T-shape freely floating breakwater with a built-in oscillating water column (OWC) chamber are analyzed in two dimensions. The Bernoulli–Euler beam equation is coupled with the equations of rigid and elastic motions of the breakwater and the VLFS. The interaction of waves between the floating rigid breakwater and the elastic VLFS is formulated in a consistent manner. It has been shown numerically that the structural deflections of the VLFS can be reduced significantly by a suitably designed reverse T-shape floating breakwater.  相似文献   

斜向波对直立式防波堤堤头作用的试验研究     

唐筱宁  饶永红 《海岸工程》2005,24(2):7-12

直立式防波堤堤头在斜向波浪作用下波浪力的计算在现行的技术规范中尚属空白。通过物理模型试验给出了堤头结构设计所需的波压分布图，指出了波浪入射方向和地形对堤头所受波浪力的贡献有时可以超过波高和波周期，根据现行规范按波浪正向入射计算堤头所受的波浪力偏于安全。  相似文献   

Numerical prediction of performance of submerged breakwaters   总被引：1，自引：0，他引：1  

A. Chiranjeevi Rambabu  J.S. Mani 《Ocean Engineering》2005,32(10):88-1246

The results of a numerical model study on the transmission characteristics of a submerged breakwater are presented. Study aimed to determine the effect of depth of submergence, crest width, initial wave conditions and material properties on the transmission characteristics of the submerged breakwater. The results highlight the optimum crest width of the breakwater and optimum clear spacing between two breakwaters. A submerged permeable breakwater with d_s/d=0.5, p=0.3 and f=1.0, reduces the transmission coefficient by about 10% than the impermeable breakwater. The results indicates an optimum width ratio of B/d=0.75 for achieving minimum transmission. By restricting the effective width ratio of the series of breakwaters to 0.75, studies were conducted to determine the effect of clear spacing between breakwaters on transmission coefficient, suggesting an optimum clear spacing of w/b=2.00 to obtain K_t below 0.6.  相似文献   

Effect of Berm Width and Elevation on Irregular Wave Run-Up     

Chen Guoping  Yu Kuang-ming  Zhang Jiachang Assistant Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing Prof.  Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1991,(4)

This paper discusses the effect of berm width and elevation of composite slope on irregular wave run-up. Based on the data obtained from model tests, the formula and distribution of irregular wave run-up on composite slope are derived. The changing of wind speed, width and elevation of the berm are considered comprehensively. The wave run-up with various exceedance probability can be es-timated utilizing the distribution curves of irregular wave run-up.  相似文献   

Calculating Method and Verification of Wave Pressure Distribution on the Breast Wall of Mound Breakwater     

Lu Wujiang Associate Prof.  Hohai University    Nanjing 《中国海洋工程》1992,(4)

In this paper, the calculating charts and formulae about wave pressure on the breast wall are derived with seven parameters on the basis of physical model study. The verification shows that the charts agree with the example, and are adopted in the Specifications of Fishery Harbours Breakwater by the Ministry of Agricultures.  相似文献   

A comparison of several wave spectra for the random wave diffraction by a semi-infinite breakwater     

Hong Sik Lee  Sung Duk Kim 《Ocean Engineering》2006,33(14-15):1954-1971

A comparison of the diffraction of multidirectional random waves using several selected wave spectrum models is presented in this paper. Six wave spectrum models, Bretschneider, Pierson–Moskowitz, ISSC, ITTC, Mitsuyasu, and JONSWAP spectrum, are considered. A discrete form for each of the given spectrum models is used to specify the incident wave conditions. Analytical solutions based on both the Fresnel integrals and polynomial approximations of the Fresnel integrals and numerical solutions of a boundary integral approach have been used to obtain the two-dimensional wave diffraction by a semi-infinite breakwater at uniform water depth. The diffraction of random waves is based on the cumulative superposition of linear diffraction solution. The results of predicted random wave diffraction for each of the given spectrum models are compared with those of the published physical model presented by Briggs et al. [1995. Wave diffraction around breakwater. Journal of Waterway, Port, Coastal and Ocean Engineering—ASCE 121(1), 23–35]. Reasonable agreement is obtained in all cases. The effect of the directional spreading function is also examined from the results of the random wave diffraction. Based on these comparisons, the present model for the analysis of various wave spectra is found to be an accurate and efficient tool for predicting the random wave field around a semi-infinite breakwater or inside a harbor of arbitrary geometry in practical applications.  相似文献   

Experimental study of strong reflection of regular water waves over submerged breakwaters in tandem   总被引：3，自引：0，他引：3  

Yong-Sik Cho  Jong-In Lee  Young-Taek Kim   《Ocean Engineering》2004,31(10):88-1335

A series of laboratory experiments was carried out to investigate the strong reflection of regular water waves over a train of submerged breakwaters. Rectangular and trapezoidal shapes of submerged breakwaters are employed and compared for reflecting capability of incident waves. Measured reflection coefficients of regular waves over impermeable submerged breakwaters are verified by comparing with those of the eigenfunction expansion method. A very good agreement is observed. Reflection coefficients of permeable submerged breakwaters are less than those of impermeable breakwaters. The trapezoidal shape is recommended for a submerged breakwater in terms of reflecting capability and practical application.  相似文献   

随机载荷下的疲劳损伤计算公式     

伍义生 《海洋工程》1994,(1)

本文推导了随机载荷下的疲劳损伤计算公式。数值计算结果表明：Ｐ．Ｈ．Ｗｉｒｓｃｈｉｎｇ给出的公式在宽带情况下与实际情况不符；Ｇ．Ｃｈａｕｄｈｕｒｙ给出的公式在窄带情况下与实际不符；本文绘出的公式不仅适合于窄带，也适合于具有各种不同带宽的宽带随机载荷。  相似文献   

防波堤损坏特点与其成因的关系   总被引：5，自引：2，他引：5  

李炎保  蒋学炼  刘任 《海洋工程》2006,24(2):130-138

利用日本《被灾防波堤集览》、葡萄牙锡尼斯防波堤、日本六小河原港防波堤、中国大连渔港、台湾基隆港等61件典型损坏案例及其它参考文献所涉及的140余件案例,讨论了防波堤损坏平面形态与断面部位的特征。根据防波堤损坏特点,从波浪水动力学特性、结构、地基和施工多方面分析了损坏原因与损坏特性之间的关系,从而深化对防波堤工作机理的认识。  相似文献