共查询到18条相似文献，搜索用时 921 毫秒
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介绍了全球定位系统接收机自主交换格式(R INEX)标准数据文件,然后以SuperStar GPS-OEM主板接收的二进制原始数据为例,详细介绍GPS主板原始数据向标准的R INEX数据格式的转换方法及编程实现。该方法对不同类型的GPS(OEM)接收机原始数据处理具有借鉴作用。 相似文献
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Huffman与LZW算法在海洋观测浮标通信数据压缩中的应用研究 总被引：2，自引：2，他引：0
在现有两种比较主流无损压缩算法基础上(Huffman算法和LZW算法),根据海洋观测浮标采集的观测数据特点,比较两种压缩算法的优缺点,并通过布放在西太平洋海域的一套观测浮标数据进行数据验证。结果表明,使用Huffman算法和LZW算法分别对海洋观测浮标数据进行压缩,两者的压缩率都基本可达50%左右甚至更低,Huffman算法压缩率较优,而LZW算法复杂度较优。通过分析,可证明这两种无损压缩算法都能有效地提高深远海通信效率和降低通信成本,同时也提高了科学观测数据的安全性和保密性,可根据实际情况选择在深远海观测浮标数据通信中应用。 相似文献
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在研究GPS系统的基础上建立了GPS观测数据的仿真模型,编制了相应的计算机程序。仿真模型包括卫星参数模型、动力学模型和观测误差模型。仿真计算表明,卫星参数模型和动力学模型真实地反映了卫星的运动规律;误差模型反映了观测环境对信号传播的影响。同时可以调节和选择仿真模型的参数,仿真选择了地面静态和地面低动态的观测数据,这对于论证GPS定轨、导航算法、设计GPS接收机等有一定的实用价值。 相似文献
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本文介绍了两种型号GPS接收机实时读取观测数据、星历信息的输入码,讨论了海洋DGPS卡尔曼滤波算法及自适应技术,通过实例计算,得出几点有益结论。 相似文献
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北斗一代和北斗二代短报文每次通信数据长度只有78个字节，每次通信后间隔60秒或者300秒才能进行下一次通信，远远满足不了海洋观测实时通信的需求。设计了一套基于北斗短报文的海洋观测实时通信系统，北斗多卡机作为数据发送端，采用哈夫曼压缩算法将观测数据压缩后分成多个数据包，通过多个北斗卡分别发送，岸站接收系统接收到分包的数据后，将接收的数据包解压缩并整合成完整的观测数据。哈夫曼压缩算法将观测数据压缩50%左右，将1组观测数据压缩后发送3次，通过岸上3个月和海上1个月的测试，观测数据接收成功率达到了96%以上，验证了基于北斗短报文的海洋观测实时通信系统的可行性和实用性。 相似文献
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针对海底声学探测仪器采集数据量大而存储容量有限、数据传输带宽不足的实际问题,基于Lempel-Ziv-Welch(LZW)无损压缩算法,研究海底声学探测数据的实时压缩方法,提高数据压缩效果、节省传输带宽。并在LZW无损压缩算法的基础上结合数据存储的特点对压缩结果进行内存重新分配,极大提高压缩比(压缩数据大小/原始数据大小)。利用海底地震仪(OBS)采集的原始声学探测数据进行测试验证,结果表明该方法对于OBS声学探测数据有很好的压缩比,可用于对OBS采集的声学探测数据进行压缩处理,对于海底探测仪器的研发有很好的指导意义。 相似文献
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《Marine Geodesy》2012,35(1):1-22
AbstractThe deep seafloor is closest to the Earth’s interior and there are complicated interactions in the physical and biological processes of the seafloor. Oceanographic parameters such as temperature, salinity, and ocean current can provide support for climate prediction. Therefore, the long-term observation of the deep seafloor is critical to the study of global climate change and the biodiversity in complex environments. For the requirements of long-term observation and remote data transmission in the deep sea of the South China Sea, a seafloor observation prototype system is designed in this paper as a stand-alone observation platform. We then proposed a date management method based on Controller Area Network to ensure the data quality. Distributed data management can be performed through system layering, and strict data transmission standards are established between each layer. At the same time, aiming at the difficulty of seafloor video data transmission in real-time, a new solution based on satellite communication technology, object detection technology, and high-efficiency compression coding technology of video images is proposed to provide support for seafloor biodiversity research. The observation data from the experiment are given, and these results show that the system can meet the requirements of long-term observation and remote real-time data transmission, and the reliability of the system is verified. 相似文献
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为提高水印的不可见性,提出1种基于水印信息压缩的图像小波域水印算法.通过细化处理和骨架缩放技术将水印图像浓缩,减少要加入的水印数据量.压缩后的水印被嵌入到图像三级小波分解后的低频逼近系统上,并通过逆过程进行水印提取,嵌入的水印具有较高的不可见性和较好稳健性.仿真实验证明算法具有很好的不可见性,经滤波、噪声、图像压缩和剪切等攻击后仍然能较好的提取水印. 相似文献
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This study analyzes and summarizes seven main characteristics of the marine data sampled by multiple underwater gliders. These characteristics such as the big data volume and data sparseness make it extremely difficult to do some meaningful applications like early warning of marine environment. In order to make full use of the sea trial data, this paper gives the definition of two types of marine data cube which can integrate the big marine data sampled by multiple underwater gliders along saw-tooth paths, and proposes a data fitting algorithm based on time extraction and space compression(DFTS) to construct the temperature and conductivity data cubes. This research also presents an early warning algorithm based on data cube(EWDC) to realize the early warning of a new sampled data file.Experiments results show that the proposed methods are reasonable and effective. Our work is the first study to do some realistic applications on the data sampled by multiple underwater vehicles, and it provides a research framework for processing and analyzing the big marine data oriented to the applications of underwater gliders. 相似文献
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Despite rapid progress in improving mass-storage density and digital communication system performance, compression of hydroacoustic image data is still significant in many engineering and research areas since it can overcome data storage and transmission bandwidth limitations. In this paper, we present a novel and effective approach for lossless compression of hydroacoustic image data which consists of two stages. The first stage reduces the information redundancy. We propose several new techniques to remove redundancy between data samples, data blocks, and data frames. The second stage uses a newly developed cascade coding scheme. This simple scheme can achieve an efficiency of 97%. A decomposition algorithm is presented for finding the optimal cascade coding parameters. The algorithm decomposes a multivariable optimization problem into a series of one-variable optimizations. Our two-stage algorithm offers a compression ratio of 2-3 and provides an exact recovery of the original data. Because of its simplicity, the algorithm can be incorporated into a variety of echo sounder systems. The compression algorithms can also be implemented using low-level assembly language to meet the requirements of real-time applications 相似文献
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当前,很多海洋监测平台利用卫星进行数据传输,卫星通信虽然有其自身的优点,但也存在一个突出的问题-通信费用高.针对通过卫星发送的海洋监测数据的特点,采用Huffman数据压缩技术对数据进行压缩,可以提高通信效率,降低通信费用.论文主要介绍了Huffman数据压缩技术原理以及如何将其应用到海洋监测平台的卫星数据通信中. 相似文献