Abundance,distribution and habitat preference of Hippocampus guttulatus and Hippocampus hippocampus in a semi‐enclosed central Mediterranean marine area          下载免费PDF全文

Michele Gristina  Frine Cardone  Roberto Carlucci  Laura Castellano  Sergio Passarelli  Giuseppe Corriero 《Marine Ecology》2015,36(1):57-66

Population abundance, distribution and habitat preference of the Mediterranean sympatric seahorses Hippocampus guttulatus and Hippocampus hippocampus were investigated in a semi‐enclosed sea system (Apulian coast, Ionian Sea). A total of 242 individuals of seahorses were sighted in the 11 transects surveyed in summer 2011. Hippocampus guttulatus (n = 225) were 14 times more abundant than H. hippocampus (17). The mean abundance of H. guttulatus for all the pooled sites was 0.018 m^?2 (SE ± 0.003) ranging from a maximum of 0.035 (SE ± 0.007) to a minimum of 0.008 (SE ± 0.002). The size structure of long‐snouted seahorse shows a population ranging from 7 to 14 cm (SL) with a peak at 10 cm (TL). Juveniles (96.0 ± 8.0 mm) represent a significant fraction of the population, accounting more than 21% of the sighted individuals. In Mar Piccolo, H. guttulatus is able to shelter both in monotonous habitats, including the algal beds, and diversified ones, such as the rich filter‐feeder communities that colonize hard substrates. By contrast, H. hippocampus is mainly associated with habitats of low complexity. Today, the Mar Piccolo di Taranto is among the most heavily polluted water bodies in South Italy, with trace metals, hydrocarbons, pesticides and organic wastes affecting both biotic and abiotic matrices. However, despite the high level of degradation, the presence of a large mussel farm has avoided the impact of towed fishing gears, and eutrophication of water bodies has ensured a high trophic level that supports large crustacean populations, potential prey for seahorses.  相似文献   

水声通信及组网的现状和展望   总被引：1，自引：0，他引：1  

朱敏  武岩波 《海洋技术学报》2015,34(3):75-79

水声通信是海洋中无线信息传输的主要技术手段。水声通信技术在海洋环境监测、水下航行器/载人潜水器作业等方面有着广泛应用。同时,水声信道传输状态多变、海洋作业环境恶劣,对通信算法和设备可靠性有较高要求,水声通信及组网成为目前的研究热点。文中面向海洋环境监测领域,从水声通信物理层技术、网络技术及组网应用等方面进行介绍,并对未来技术趋势进行展望。  相似文献   

深水新型水下立管支撑平台研究     

潘泽华  赵耀  严俊 《海洋工程》2015,33(6):119-128

FPSO系统在深海海洋油气资源开发中扮演着重要的角色,而深水FPSO系统水下立管管路较长,立管整体重量较大,立管在水流作用下产生的涡激振动也较强,这些将给FPSO主船体带来严重的稳性、强度及疲劳问题。鉴于此,深海FPSO系统在油气资源开发过程中,须在水下一定深度设置若干水下软管支撑浮体,用以支撑来自深海海底的管线,减轻深水立管对FPSO的负载作用。随着深海资源开发的深入发展,传统水下软管支撑浮体作为FPSO系统的关键装备已经无法满足深海开采的需求,寻求大型化、深海化、生命周期长久化的新型水下立管支撑平台迫在眉睫,设计简便快捷、低风险的安装方法成为其开发过程中的重点和难点。详细描述了水下软管支撑浮体的产生及其发展历程,针对深海开发的需求提出了新型立管支撑平台的新概念,着重对新概念下下水安装更便捷的耐压立管支撑平台设计原理及其下水安装方式展开了分析,最后对水下软管支撑浮体和新型立管支撑平台的关键技术进行了总结,并提出了需进一步解决的问题。  相似文献   

主动声纳探测效能评估的HMG法     

李胜全  李宏武  高飞  潘长明  孙磊 《海洋测绘》2015,35(3):67-70

海洋水声环境时空变化显著,评估其对主动声纳探测效能的影响具有重要的理论意义和应用价值。提出HMG方法用以评估水声环境效应对主动声纳探测的影响。采用UMPE(The university of miami parabolic equation)、CANARY、JACKSON模型模拟特定海洋环境下的传播损失、环境噪声、混响分布,将模拟结果融入主动声纳检测概率模型,计算检测概率。评估结果发现近场检测概率较高,远场可检测的区域与声能汇聚区一致。  相似文献   

无人机遥感系统的集成与飞行试验研究   总被引：4，自引：1，他引：3  

吕书强  晏磊  张兵  杨绍文  焦健  赵红颖  秦其明  曾琪明 《测绘科学》2007,32(1):84-86

为了拓展无人机在民用遥感领域的应用,形成对卫星遥感和有人机航空遥感有益的补充,本文首先介绍了集航迹规划、空中遥感控制、数据获取、数据压缩解压缩、数据传输、快视图实时显示等功能为一体的无人机遥感系统。然后对该系统的多次遥感飞行试验进行了介绍。最后根据所获取的遥感影像和飞行辅助数据对飞行试验进行了质量评价。  相似文献   

一种基于多目视觉的无人机实时定位方法     

王辰  郑顺义  朱锋博  桂力 《测绘通报》2018,(4):32-35,82

提出了一种基于多目视觉的实时无人机自动定位方法。该方法将多相机和多台计算机联合组建局域网,通过相机标定、图像同步采集、背景差分与前方交会等实现无人机自动检测与定位。为了验证该方法的有效性,开发了一套无人机检测和定位的软硬件系统,试验结果表明该方法是可行、有效的,定位精度满足要求。  相似文献   

机载水质定点分层采样装置设计与实现_^*     

陈城  方卫华  韩继伟  符伟杰 《水文》2023,43(4):53-56+63

为了提高水质采样的自动化、精准化以及信息化水平,针对传统水质采样（人工采样和无人船采样）的低效率、高成本、周期长以及难以到达采样地点等问题,提出了利用无人机技术取代传统的水质采样方式,该装置由旋翼无人机、采样装置以及标准取水容器组成,其采样过程首先是通过拨动无人机遥控器上的开关按钮预先设置好采样深度,然后在无人机地面站输入经纬度信息使得无人机能够飞行到指定的采样地点,进而拨动遥控器上的一键采样按钮自动完成取水操作,最后再一次拨动遥控器上的返航按钮使得无人机自动返航回到初始位置。该方法相比于传统方式具有安全性高、成本低等优势,有利于推动水文仪器现代化发展。  相似文献   

应用光照模型的交通车辆识别定位的高分辨率遥感方法   总被引：1，自引：0，他引：1  

曹天扬  申莉 《测绘学报》2015,44(1):39-45

针对识别和定位路面上每辆汽车这一交通遥感图像处理的核心环节,提出一种解决方法。应用光照模型推导出路面、车辆(深浅两类)、汽车阴影在全色遥感影像中的亮度差异与亮度变化特征。以亮度差异为基础建立了能够将车辆区域从路面遥感图像中分割出来的图层分离算法。针对密集行驶的汽车因阴影相互覆盖而容易被误识别为一辆大型车的问题以及浅色车因深色车窗造成的识别结果割裂问题,利用亮度变化特征以及阴影、车窗与汽车的位置关系设计了车辆区域内的阴影和车窗干扰消除算法,通过闭运算实现了遥感图像中的汽车识别与定位。选用10幅交通遥感图像进行了测试,对浅色车的识别率大于92%,对深色车的识别率大于87%。  相似文献   

基于BDS的主辅站技术在车载导航中的应用研究     

邹浜  王伟权  周文胜  高云志 《测绘工程》2015,(5)

为了克服传统车载导航定位技术的不足,提高定位精度,文中将基于北斗卫星导航系统的主辅站技术应用于车载导航中,主辅站技术有着可靠性高,无需双向数据传输和服务用户无数量限制等优点。理论研究和实践表明,基于主辅站技术的车载导航定位系统,其定位精度可以达到厘米级,实现车道级定位导航,并能在车辆即将越界时提供预警,防止车辆违章,具有一定的实用价值。  相似文献   

Exploring Social and Spatial Patterns in Private Vehicle Fuel Efficiency: a case study of Brisbane and Sydney,Australia     

Tiebei Li  Jago Dodson  Neil Sipe 《The Australian geographer》2015,46(2):217-233

Australian cities have seen continued growth in private car travel that has resulted in increasing vehicle energy consumption and greenhouse gas emissions. While much research has shown that vehicle demand is related to urban spatial structure, very little research has investigated the spatial patterns of private vehicle fuel efficiency (VFE) and its association with socio-spatial circumstances in urban areas. This study has combined State-level motor vehicle registration datasets with standard vehicle efficiency measures that permit a comprehensive understanding of spatial variation of VFE in urban areas. A spatial-based technique was applied to explore intra-urban patterns in socio-spatial conditions of private vehicle efficiency in Brisbane and Sydney. In both cities, the VFE of the private vehicle fleet tends to be lower in outer suburbs than in middle and inner suburbs. The analysis further shows that by linking the standard vehicle efficiency measures to the entire urban fleet datasets the VFE outcome showed a moderate relationship to socio-spatial variables in both cities. The built environment and household economic status are more transferable factors that relate to the VFE across different urban contexts. Outcomes from this research are of relevance to policy makers charged with identifying highly oil-vulnerable communities and designing intervention strategies to improve household vehicle efficiency.  相似文献