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数字相关器在信号检测系统、通信系统中有着较为广泛的应用,如用于颗粒的测量、海洋的探测、雷达接收机等。本文通过对信号噪声互相关性原理的分析,提出了一种基于数字相关的检测微弱信号的算法,用于检测淹没于强噪声中的微弱周期信号,运用这种算法可以检测到一般方法难以测量的微弱信号,提高了微弱信号检测的精度。 相似文献
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《科技通报》2016,(3)
研究基于Lab View信号优化检测方法。传统的信号检测方法多是采用专用仪器进行信号测量分析,一旦待测信号较弱,就会严重影响检测速度,且无法保证检测的准确度,不能满足试验平台的功能要求。为此,提出一种基于Lab View信号优化检测方法。针对初始信号中含有大量的无用信号和噪声信号,根据小波变换原理进行滤波去噪处理,最大化的保留重要信号及有用信号,提取待测信号的特征波形,利用相关检测函数进一步将有用信号从噪声信号中分离出来,实现基于Lab View信号的优化检测。实验结果表明,采用Lab View开发设计的信号优化检测虚拟实验室,在进行信号检测时,能够提高检测的精度与稳定性,节约运行成本,具有显著的优越性。 相似文献
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针对当前光电检测系统微弱信号检测存在的检测误差大、抗噪能力差等不足,设计了小波分析和最小二乘支持向量机相结合的光电检测系统微弱信号检测方法。首先采用小波分析对光电检测系统微弱信号进行处理,消除微弱信号中的噪声,抑制噪声对微弱信号检测结果的干扰,然后引入混沌分析算法对光电检测系统微弱信号进行重构,并采用最小二乘支持向量机建立光电检测系统微弱信号检测模型,最后进行了光电检测系统微弱信号检测的仿真对比测试。结果表明,本文方法可以实现高精度的光电检测系统微弱信号检测,检测速度和检测精度均优于当前其它光电检测系统微弱信号检测方法,具有更高的实际应用价值。 相似文献
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光电检测技术是光学技术与电子技术相结合以实现对各种光学物理量的检测与测量,当应用于恶劣的环境中,待测的光信号易受到外界的干扰,信号强度较弱时,设备要想提取准确完整的信号时,要求对检测电路提出更高的要求,如何将微弱信号从噪声中提取、恢复和增强成为光电检测的关键。 相似文献
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针对基于四象限压力传感器阵列的迎角测量方法中传感器信号受到干扰的问题,讨论了在其预处理中应用小波包变换进行信号分离提取的方法。根据小波包分解理论,对信号进行小波包分解,信号中频率不同的部分落在不同的尺度上,剔除反映干扰的变换尺度,提取出有用信息。结果表明,该方法可很好地提取信号的主要特征信息,也有效地去除了确定性干扰和随机噪声,与传统的信号滤波方法相比较具有明显的优点,同时为后续的信号处理奠定了基础。 相似文献
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目标噪声特征提取是被动声纳目标识别系统的关键技术。首先提出了一种利用从噪声极限环中提取的非线性特征来分析舰船噪声信号的新方法,然后采用基于自适应遗传BP算法的神经网络对提取的特征进行分类。实验结果表明,该系统具有较好的分类效果。 相似文献
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The problem of designing robust systems for the detection of stochastic signals in noise is considered for the large-sample-size, small-signal case. By applying two previously-established models for the detection of stochastic signals, known results for the robust detection of deterministic signals are extended on a limited basis to the stochastic- signal case. The proposed detectors are seen to be robust over a class of possible noise statistics, based on a Huber-Tukey mixture model, which contains noises characterized by heavy-tailed probability density functions. In addition, numerical results are presented which verify the robustness property of the proposed detectors over wider classes of noise mixtures. 相似文献
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水声是人类迄今为止所知道的唯一能在海洋里远距离传播的能量形式。其他的物理媒介,如可见光、电磁波、激光等在海水里传播时会很快衰减掉,因而无法传向远方。凡是利用水声能量进行观测、通讯的系统,均称为声呐系统。水声信号处理和声呐技术是一门发展迅速、需求推动力强大、应用前景异常广阔的学科。在声学领域的众多分支学科中,没有其他学科像水声学那样,其发展受着战争需求的推动。反过来,水声学的发展又为水下战武器装备的研制和创新注入活力。文章介绍我国改革开放40年来水声信号处理和声呐技术领域的研究进展和发展前景。包括水声信号建模、声场匹配、海洋波导和内波现象的探索与研究、水声信道的时/空相关特性、水下目标辐射噪声的提取及检测技术、高分辨力水下成像技术,以及水下语音、图像传输和抗干扰技术。文章还介绍了我国"863"计划海洋监测主题所取得的成就。提出了我国水声信号处理和声呐技术领域的发展前景,包括深海声学、北极声学、安静型潜艇辐射噪声检测、水下-水面-空天一体化信息获取和融合技术等,以及在建设海洋强国战略中不可替代的独特作用。 相似文献
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《Journal of The Franklin Institute》2002,339(6-7):499-520
In this paper we are concerned with the problems of (1) tracking or estimating the unknown, time-varying instantaneous frequency (IF) of a chirp signal from a multi-component signal (we assume our multi-component signal to be formed of additive chirp signals, disjoint in the time–frequency domain, and Gaussian noise) and (2) reconstructing a specific chirp signal based on the estimate of its IF found at (1). The algorithm we developed is based on a previously proposed method adapted now for the case of multi-component signals. It combines an adaptive smoothing procedure with a noise resistant Fourier filter to generate an algorithm with an extremely fine frequency resolution. The method is non-parametric, that is, we assume no prior knowledge about the form of the time-varying IF of the chirp or about the chirp itself. We demonstrate how the method works on simulated data and compare its performance to other presently used procedures. 相似文献
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杨立强 《中国科学院研究生院学报》2005,22(3):359-363
利用LOG算子和改进相干算法相结合来提高信噪比和地震资料分辨率 ,并同其他方法作了比较 .模型数据与实际数据的应用效果证明 ,该方法具有较强的信噪分离作用 ,能有效提高地震资料分辨率 ,该方法是实用的 . 相似文献
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《Research Policy》2019,48(9):103821
We investigate the influence of public R&D subsidies on a firm’s likelihood to form technological collaborations. Using signaling theory, we conceptualize the award of a subsidy as a pointing signal (i.e., indicating a quality attribute that distinguishes the signaler from its competitors), and the monetary amount raised through a subsidy as an activating signal (i.e., activating the quality attribute of the signaler). Drawing on the attention-based view, we investigate whether the relative salience of these signals varies between two types of signal receivers: academic and corporate partners. Using a panel sample of Spanish manufacturing firms, our results indicate that the two types of receivers attend to the two signals differently: while academic partners attend to pointing signals only (sent by the award of a selective subsidy), corporate partners react to the richer information that activating signals provide (sent by the monetary value of both selective and automatic subsidies). Our results are stronger for SMEs vis-à-vis large firms, and hold after controlling for endogeneity, selection bias, simultaneity, attrition, inter-temporal patterns in technological collaborations, and the substantive effects of subsidies. The theorized and tested dual nature of subsidy-enabled signals and their different salience to distinct partner types hold interesting implications for research on alliances, innovation policy, and signals. 相似文献