北斗系统3个频段信号反演潮位高度技术研究

全球性海平面的上升可能会对沿海地区的社会活动产生重大的影响,因此,监测和了解海平面变化显得非常重要。本文依据信号的信噪比（SNR）测高原理,通过分析2014年9月5-31日,在中国浙江省舟山市的大洋山岛上所收集的北斗3个频段的卫星信号,成功地实现潮位高度反演。其中,B1频段反演结果的标准差（STD）为33.82 cm,相关系数为95.98%;B2频段反演结果的STD为38.48 cm,相关系数为94.68%;B3频段的反演结果的STD为34.56 cm,相关系数为96.08%。这是首次关于北斗3个频段信号的SNR测高研究。本次实验论证了该方法在北斗系统上的可行性,同时对北斗B1、B2、B3频段的信号在SNR测高中的性能作了对比分析。     

赤湾验潮站搬迁前后潮位变化特征及其订正

赤湾海洋站是国家海洋局在深圳西部海域唯一的潮汐观测站点,至今已观测30多年。由于地理位置特殊,2008年起该站被选为《中国海平面公报》反映珠江口海平面变化的代表站。2012年10月该站搬至新验潮站,受此影响,其潮位观测序列产生了差异性和不连续性。本文通过计算机编程实现了对海洋站水文气象数据的质量控制。同时,采用赤湾站与邻近验潮站进行对比的方法得出新旧站的潮位差值,初步探讨了搬站前后潮位观测结果的订正方案,并研究其建站以来的历史海平面变化特征。这对确保该站潮位资料的准确性及代表性具有重要意义,同时也为珠江口海域防灾减灾、涉海工程、风暴潮预报等提供了数据支撑。     

水尺与压力式水位计数据关系的算法研究

针对海道测量中在同一验潮点人工水尺与压力式水位计同步水位观测所得不同的潮位数据,分别绘制潮位曲线,从两条相关的曲线数据中应用三次样条和拟合数学函数模型,利用计算机程序确定曲线间的线性关系,从而根据压力式水位计测得的数据确定的关系得出真实的潮位数据。     

黄浦江风暴潮位、区间降雨量和上游来水量遭遇分析

分析了黄浦江水位的主要影响因子及其相关关系。建立了黄浦江吴淞口潮位与太湖地区降雨量的联合分布模型,计算出不同频率的吴淞口设计水痊与不同频率的太湖地区设计降十量及相应的黄浦江区间降雨量相遭遇的概率,并采用水动力学模型结合外包方法确定出相应组合频率下的黄浦江设计水面线,为上海市远期设防标准的确定提供决策支持,并为论证吴淞口建闸的必要性提供科学依据。     

台风诱发暴潮极端潮位的预测方法

以杭州湾为例,根据水文站历史潮位资料,采用改进的灰色马尔可夫预测模型对台风诱发暴潮的极端潮位进行预测.同时采用复合极值分布理论对可能出现的极端潮位进行概率预测,使预测结果更为接近真实数值.     

多波束测深数据处理及成图

针对多波束测深系统测量的特点,分别分析声速改正技术和潮位改正技术。从声速在海水中的传播出发,阐述海水中声速的测量,对声速的较正方法进行探讨,随后针对潮汐效应的影响,对多波束测深数据进行潮位改正,并利用海上试验实测的多波束测深数据,将处理后的数据绘制成海底地形数字地图。     

Tidal analysis in the venturi-shaped area between Zhenhai and Shenjiamen in the East China Sea

In order to better understand the general tidal features in the venturi-shaped area between Zhenhai and Shenjiamen in the northern coastal region of Zhejiang Province in the East China Sea, the tidal data were obtained from both the three permanent tide stations of Zhenhai, Dinghai and Shenjiamen, and four temporary tide stations of Mamu, Chuanshan, Guoju and Liuheng, along with the current speed being observed at Luotou Waterway. Results from harmonic analysis show that: (1) The area was dominated by shallow water tides with irregular semi-diurnal features, and the smallest tidal range occurred in the area near a crossing line between Zhenhai and Dinghai stations, indicating that a tidal node existed in the southern Hangzhou Bay; (2) Formulae, HS2/HM2 >0.4 and gM2-(gK1+gO1)=270° (where H and g are harmonic constants), could be used as judging criteria for high and low tidal level diurnal inequalities; (3) The duration difference between ebb and flood tides could be roughly assessed by the ratio of HM4 vs. HM2; and the larger the ratio is, the bigger the duration difference is. At the same time, the duration period could be assessed by 2gM2-gM4, the epoch difference between M2 and M4 tidal constituents. If 2gM2-gM4 <180°, then the ebb duration is longer than the flood duration; if 180°< 2gM2-gM4 <360°, the result is reversed; (4) Taking Dinghai station as a center point, the highest tidal levels and the average high tidal levels, as well as the average tidal ranges at all stations became higher and larger both southeastwards and northwestwards, while the lowest tidal levels and the average low tidal levels appeared to be lower both southeastwards and northwestwards; and (5) The tidal patterns were not all in line with the tidal current patterns. As a conclusion, the smallest tidal range occurred in the narrow part of the venturi-shaped area. Along the both sides of the area, the highest tidal level and tidal range became higher and larger, while the lowest tidal level became lower with the increase of the distance from the narrow throat area. This is somehow different from the theory that the tidal level increases gradually when it moves towards the top narrow area of a V-shaped bay or estuary.     

风暴潮模拟中潮位对风拖曳力系数的影响研究

近年来,应用数值模型模拟台风引起的风暴潮运动越来越普遍,模型中对于风拖曳力系数的确定,一般都从相对风速出发,可引用的公式也较多,但这些公式很少考虑潮位变化对此系数的影响.在强潮河口、海岸海域,潮位变幅大,最高潮位甚至可达风速参考高度(10m)的近一半,如长江口和杭州湾.在数值模拟中不考虑风暴潮和天文潮共同引起的潮位变化,会造成风应力高潮时被低估、低潮时被高估的现象,从而影响风暴潮模拟的精度.为此本文对现有的风拖曳力系数加以改进,提出了考虑潮位影响的风拖曳力系数表达式,并应用于长江口、杭州湾9711号台风风暴潮的模拟中,增水模拟结果得到了明显改善,可进一步推广应用于强潮河口、海岸的风暴潮增水模拟中.     

我国南极长城站和中山站锚地选址及测绘回顾

在1997年以前,我国南极考察船到达南极长城站和中山站附近水域后,由于没有合适的锚地而多次出现险情。成功地在南极长城站和中山站水域完成锚地选址和锚地测绘任务,是一件非常重要的事情。它是南极科考船安全避风、高效货物装卸的保证,它对于我国南极科学考察和基站建设有着十分重要的意义。