黄河防汛计算机系统

黄河防汛计算机系统杜学胜王春青李根峰（黄委会水文局水文水资源情报预报中心）１引言１９４６年出现了世界上第一台电子计算机,短短的几十年时间计算机以强大的生命力和迅猛的发展速度渗透到各个领域。简单地讲,电子计算机的发展经历了电子管、晶体管、集成电路和大规...     

Simulation of Suspended Sediment in the Yellow and East China Seas

Described is an initial attempt to simulate the suspended sediment dynamics relating to tidal and wave forcing during summertime in June 1980 and August 1981 for the Yellow and East China Seas continental shelf. The cohesive/non-cohesive sediment resuspension and movement generated by the interaction between current and wave are modeled by use of ECOMSED and WAM Cycle 4. Model results are compared with observations in US-China Marine Sedimentation Dynamics Program performed for 1980-81 at off the Changiiang estuary. The main features of simulations show that suspended sediment concentrations during the summer decreased markedly offshore as observed during the simulation periods. As for some discrepancies for the mouth of the estuary with high river discharges, i.e., the Changjiang River, the model did not properly reproduce the over-mixing situation in the summer; thus distinct vertical concentration variation in this local region is not agreeable with observation. However, general dispersal patterns of suspended sediment movement seem to be agreeably reproduced for the nearshore shallow region. Some of the procedures of simulation and results are presented and discussed.     

AUV Local Path Planning Based on Acoustic Image Processing

The forward-looking image sonar is a necessary vision device for Autonomous Underwater Vehicles （AUV）. Based on the acoustic image received from forward-looking image sonar, AUV local path is planned. When the environment model is made to adapt to local path planning, an iterative algorithm of binary conversion is used for image segmentation. Raw data of the acoustic image, which were received from serial port, are processed. By the use of ＂Mathematic Morphology＂ to filter noise, a mathematic model of environment for local path planning is established after coordinate transformation. The optimal path is searched by the distant transmission （Dt） algorithm. Simulation is conducted for the analysis of the algorithm. Experiment on the sea proves it reliable.     

针对GF-1遥感影像的基于影像与基于辐射传输模型的两种交叉定标方法比较

"高分一号"配置了4台16m分辨率多光谱宽幅(WFV)相机,组合观测幅宽达到800km。为了将其应用于定量遥感,需要对其进行精确的辐射定标。目前针对高分一号卫星有两种交叉定标方法,都在传统方法的基础上进行了改进。一种是基于影像的交叉定标方法(image-based),另一种是基于辐射传输模型和二向反射分布函数的交叉定标方法(RTM-BRDF)。本文采用这两种方法对高分一号(GF-1)的4个相机进行辐射定标,并对这两种方法进行了对比分析,发现对于WFV2和WFV3这两个近似星下点成像相机,image-based方法可以得到精度较高的辐射定标系数,而对于WFV1和WFV4这两个非星下点成像相机来说,RTM-BRDF方法得到的定标系数精度较高。因此,最终将两种方法结合给出GF-1 4个相机最终的定标系数。     

基于稳健估计的白桦叶片铜元素含量反演

根据阔叶叶片模型（a model of leaf optical properties spectra,PROSPECT）叶片辐射传输模型机理,利用一次范数稳健估计估算叶片结构参数N和铜元素的吸收系数k_Cu。选取黑龙江呼玛地区作为研究区,利用美国ASD公司的FieldSpec 3 Hi-Res光谱仪野外测定白桦叶片的反射光谱,实验室测定相应叶片的铜含量,利用改进的PROSPECT-Cu模型进行白桦叶片铜元素含量反演。通过与野外样品测定值和反演值进行比较分析,决定系数为0.963。研究结果表明,反演结果得到的叶片Cu含量是准确的,反演方法是可行的。     

水下无线电能传输研究进展

首先对水下无线电能传输技术进行了分类,然后给出了磁感应式水下无线电能传输的基本结构和工作原理,讨论了该技术的最优工作频率、传输距离、线圈结构选择、涡流损耗与频率分裂现象.随后简要给出了磁谐振式水下无线电能传输技术和电场耦合式水下无线电能传输的研究现状.最后对水下无线电能传输技术有待研究的问题进行了展望.     

我国2000年海上通信的发展前景和对策

本文根据海上通信的发展现状,展望了未来海上通信发展趋势和我国海上通信发展前景,探讨了我国海上通信的发展战略和对策。     

浅析低空智联网与无人机产业应用

无人机正处于技术快速突破与应用快速增长的重要时期,将成为低空经济发展的重要推手。低空智联网是无人机产业发展的基石,是在低空空域实现“人—机—物”三元融合万物智能互联的重要基础设施。低空智联网体系架构就是依托天空地海网络基础设施,实现传统互联网络向万物智能互联网络演进,形成适合低空业务数字化、智能化运营的实体网络空间,可为无人机产业发展提供一个网络化、数字化、智能化的运营环境,对促进低空经济发展具有重要意义。     

基于卫星短消息通信的大地测量信息传输技术

无线通信是大地测量内外业一体化生产中的瓶颈问题。首先介绍了大地测量信息传输系统的基本功能,给出了通信管理功能的基本结构,然后重点讨论了通信管理中的一些关键技术：用户终端与计算机控制程序之间的信息组织、利用CRC校验和多重确认进行误码控制、建立传输队列来防止信号失锁造成的信息拥塞。最后通过试验分析,验证了利用卫星短消息通信进行大地测量信息传输的可行性。