A brief analysis of the positioning accuracy for the TH-2 satellite system

The TH-2 satellite system is China's first microwave surveying satellite system based on distributed interferometric technology. In this paper, the positioning accuracy of the satellite system is studied. According to the InSAR mechanism model, the error sources that affect the positioning accuracy are analyzed, and the InSAR data processing flow is designed. The satellite positioning accuracies in plain and mountain area are tested and verified by using the baseline measurement accuracy and ground processing accuracy of ground design and on-orbit test. The tests show that the plane and elevation accuracy of the satellite system after processing the measured data on orbit is better than that of the original simulation analysis at the baseline length of 700~1050 m in formation configuration, it can satisfy the surveying and mapping precision of 1∶50 000 scale topographic map in plain and mountain area for China

滨海城市“气候承载—空间适应”方法研究——厦门气候承载空间模拟分析

城市气候承载力作为城市适应气候变化的核心测度,反映城市系统与气候系统之间互馈关系,其空间状态关乎城市安全与可持续发展。基于DPSIR和状态空间法,构建城市气候承载空间概念模型、气候承载力评价指标体系与评测模型,提出气候承载—空间适应方法体系;结合GIS,以厦门为具体案例城市,定性、定量、定位进行城市气候承载空间模拟分析,创建城市气候承载地图(UCC Map),判定气候承载—空间适应热点区域,进而提出城市气候承载—空间适应优化建议。以补充\"气候变化\"与\"城市空间\"相互调节适应的空白,为我国城市积极应对气候变化提供技术支撑。国家社会科学基金重大项目“基于智慧技术的滨海大城市安全策略与综合防灾措施研究”(13&ZD162);;国家自然科学基金面上项目“低碳理念下基于人工智能的城市空间结构的热岛效应模拟预测研究”(51278330

Monitoring of Inshore Aquaculture Cages Using Unmanned Aerial Vehicle

无人机(unmanned aerial vehicle,UAV)遥感具有高时效、机动灵活、高分辨率的特点,探索应用UAV遥感平台对沿海养殖区进行监测,实时掌握养殖发展动态,开展灾后应急监测,显然具有重要意义.利用UAV获取的CCD相机光谱信息,建立渔排监测指数,提出了渔排监测指数阈值快速提取算法;并针对渔排本身混合了水体和木筏2种目标物的特性,对提取结果进行图像闭合算子运算.在福建沿海古雷和可门港的实验结果表明,基于UAV获取的数据影像,利用渔排监测指数快速提取算法估算的渔排面积精度在两个区域分别达到98.9%和97.4%,与传统遥感分类方法——最大似然法相比,在同一计算平台上,计算速度提高5倍,无论精度或速度都可满足海洋与渔业管理部门在业务上的快速响应需求.此外应用UAV,以苏迪罗台风过后的三都澳海区为例,尝试开展了台风灾害造成的渔排损毁分析,初步推算出台风造成的渔排损毁面积比例.该研究表明利用UAV遥感可以为渔业管理提供有效的技术支持.Unmanned aerial vehicle( UAV) may provide a quick means to gather information of inshore aquaculture cages for the government to have an emergency response to events such as typhoons.Based on CCD imageries with 0. 1 meter resolution acquired with UAV platform and its spectral features,here we proposed a threshold method to quickly detect the distribution of aquaculture cages in two bays of southern Fujian.An identification accuracy of 98. 9% and 97. 4%,for Gulei and Kemen bays,respectively,was obtained.Meanwhile,the image processing time is reduced by 5 times,compared to the time needed using the widely accepted conventional approach-maximum likelihood method.In addition,a rough evaluation on the ruin extent of aquaculture cages by typhoon was also attempted,using UAV acquired imageries and satellite images.This study suggests that optical remote sensing with UAV holds promise for better management of inshore aquaculture activities.国家科技支撑计划(2013BAB04B01);; 厦门大学海洋科学基地科研训练及科研能力提高项目(J1210050);厦门大学大学生创新创业训练计划(201510384091

Key technologies for on-orbit azimuth antenna pattern measurement of TH-2 dual satellites

On-orbit (inflight) measurement of the antenna pattern of space-borne synthetic aperture radar (SAR) is an indispensable and important procedure for SAR calibration, performance tuning and index test. Usually, in practical on-orbit (inflight) measurement of the SAR antenna pattern, it is separated into the vertical (elevation) and the horizontal (azimuth) directions respectively. The TH-2 satellite set is made up of two satellites to enable bistatic interferometry SAR (InSAR) observation. At the beginning of the on-orbit tests, the two satellites adopted a "following" flying formation in which one satellite flew about 40 km away after the other one. In this phase, the two satellites worked independently in SAR observation model to facilitate calibration, tuning and test of the satellites individually. When conducting the azimuth antenna pattern measurement, the collected signals from the two satellites in the ground receiver were overlapped (interleaved) and superposed, leading to the difficulty of measurement with the method designed for only one satellite. Aiming at solving this problem, an efficient and fully automated signal separation method for azimuth antenna pattern measurement is proposed. Based on the modeling and analysis of the sampled signal in the ground receiver, a novel signal separation method based on three main parts: key pulse rising edge extraction, pulse position estimation and pulse amplitude estimation is proposed to realize the separation of the signals from different satellites. After signal separation, the subsequent antenna pattern measurement tasks can be done using the traditional single-satellite method. Experimental results sufficiently show the effectiveness of the proposed method. This method escorted the on-orbit tests of the satellites smoothly, and the test efficiency can be doubled compared with the individual test of each single satellite. The proposed method can be used in the on-orbit tests of similar satellites in the future

Research and application of coal exploration data management method in working face based on GIS

In order to improve the efficiency of dynamic calculation of coal reserves in the mining process of coal working face and enrich the dynamic updated data required in the construction of 3D geological model of working face in intelligent mining, a GIS based coal mining face data management method is proposed through the full analysis and in-depth research on the professional needs, business processes, technical routes and data structure of coal mining face data management. At the data level, the business process of coal exploration data management was optimized, the data structure and storage method of different types of coal exploration data were designed, the coal exploration data sharing and management of mining face based on spatial relational database were realized from using the spatial data organization and management mode. At the presentation level, the interactive management of coal exploration data and graphics was realized based on the domestic geographic information system platform, LongRuanGIS, independently developed from the bottom. At the business level, a drawing algorithm of coal exploration line was proposed to realize the rapid drawing of different coal exploration lines. The data structure, drawing style, drawing method and data management method of coal exploration point were designed to ensure the beautiful mapping of coal exploration data and efficient reuse of data; a method of dynamically updating the geological model of coal mining face by using the data of coal thickness detection was proposed, which enriches the dynamic updating data source of high-precision three-dimensional dynamic geological model of working face. The results of normalization application in many mines show that the management method of coal exploration data based on GIS realizes the unified management and sharing of different types of coal exploration data, realizes the rapid automatic mapping and dynamic updating of coal exploration data and improves the drawing efficiency of coal mine geologists. At the same time, the timely updating of coal exploration data provides convenient and effective data management measures for dynamic calculation of reserves and dynamic updating of high-precision 3D geological model, ensuring the efficient use of coal exploration data in many aspects

Measurement and control software for vehicle cooling system based on 3-access architecture

针对车辆冷却系统测控试验平台中的数据实时采集和电机控制问题,利用三层架构的开发思想,基于C#语言、Measurement Studio控件以及SQL Server数据库,在上位机中结合数据采集卡和传感器等硬件设计开发了车辆冷却系统的测控软件。详细介绍了三层架构的数据访问层、业务逻辑层、表示层在测控程序中的具体实现过程,完成了对测控数据的实时采集、存储与处理,绘制了测控数据实时曲线和历史曲线,以及实现了对风扇电机和水泵电机的控制等功能。同时,利用多次实验对测控程序的可靠性及稳定性进行了测试。实验结果表明,基于三层架构框架指导开发的软件具有更好的可读性、维护性和扩展性,满足车辆冷却系统试验平台的测控要求。Aiming at the problem of real-time data acquisition and motor control for vehicle cooling system test-bed,using the development thought of 3-access architecture,the measurement and control software of the vehicle cooling system was designed and developed by C #,Measurement Studio control and SQL Server database based on the hardware of data acquisition card and sensor in the host computer. The realization process of 3-access architecture of DAL,BLL and UI were introduced in detail in the measurement and control program,it finished real-time acquisition,storage and processing of measurement and control data,real-time curves and history curves,fan motor control and water pump motor control,and other functions. At the same time,the reliability and stability of the program were tested by several experiments.The results indicate that the software can improve the readability,maintainability and expansibility of the program,and meet the requirements of measurement and control based on 3-access architecture.福建省自然科学基金资助项目(2014J01210);; 深圳市科技计划项目(JCYJ20140417162429675

Visual Analysis of Literature Review of Phase Space Reconstruction

为探究相空间重构理论至今为止的发展历程及前景,特以CiteSpaceⅢ可视化引文分析软件为工具,通过文献计量学研究方法,对来自于Web of; Science平台的与phase space reconstruction相关1; 500篇文献按时间分布、空间分布、引文及作者分布的情况进行了汇总整理,并以图、表的形式展现。根据关键词和共现图及关键词时区图,重点考察了相空间重; 构理论的研究热点及趋势。研究表明,该理论的发文量逐年增加且势头强劲;在工程、技术领域的应用越发广泛;与多种算法相结合,可提高非线性系统的分析与预; 测精度。The primary object of the paper is to reveal the development process and; prospect of phase space reconstruction theory. The technique applied is; referred as CiteSpace Ⅲ, a visualized analysis software for citation.; The research method of literature metrology was used to classify the; fifteen hundred papers from the Web of Science platform related with; phase space reconstruction into different priorities according to time; distribution, spatial distribution, citation and author distribution.; All results were displayed in figures and tables. The hot spot and trend; of phase space reconstruction were discussed based on the keywords; co-occurrence graph and keywords time zone map. The study showed that; the amount of the publications on the theory increased year by year; harply, and it has been applied more widely in the field of engineering; and technology. Combined with a variety of algorithms, the accuracy of; the analysis and prediction of nonlinear systems can be improved.国家自然科学基

凡口铅锌矿多通道微震监测系统及其应用研究

微震监测技术是深部矿床地压监测的重要手段。简要概括了凡口铅锌矿深部矿床赋存条件、地压特征、地压灾害以及建立微震监测系统的必要性;对建立的16通道微震监测系统的组成、监测系统的性能、微震监测范围进行了详细介绍;通过对传感器布置优化分析,绘出传感器布置的一个优化分析结果的震源定位等值线实例图。采用人工放炮产生的震源对微震监测系统的震源定位性能进行测试,绘出测试结果和系统监测定位图,并比较实际测量和系统监测分析结果,两者结果对比表明,在传感器阵列内的震源定位误差不大于5m时,监测系统对震源具有较高的定位精度。采用该套系统对深部采区的大爆破余震进行监测发现,余震事件大多发生在数分钟之内,这表明目前采区围岩的稳定性较好

黄海及渤海海峡海缆建设与海底隧道

以位于北黄海的大连—烟台海底光缆和渤海海峡诸岛间的海底光缆为例,概括介绍了它们所处的海洋环境及重要的海洋开发活动状况,从中可见它们对海底光缆的作用及影响。并着重说明海缆路由的选择及确认的过程及其重要意义。最后介绍了海底光缆与海底隧道建设之间的相似及相关性,从海底光缆建设长期的的实践中,从长期开展的海底光缆建设形成的成熟工作流程及科学的工作方法中,吸取一些可资借鉴的经验教训,为未来建设海底隧道提供一些参考和帮助