共查询到17条相似文献，搜索用时 125 毫秒
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风通过影响海洋表面从而产生200 Hz以上的深海环境噪声,但有研究指出,通过风生表面波之间的非线性相互作用产生的驻波,能够与海床共振构成海底微震,从而产生10 Hz以下的噪声。针对这一新型风生噪声机制,本研究对威克岛海域10 Hz以下的极低频噪声进行了分析。比较了不同频率下海洋环境噪声功率谱级与风速的相关性,并讨论了风速和风向对设立在威克岛南北部二组水听器三联体信号的影响,结果表明2 Hz处的海洋环境噪声级与风速相关性最好,而风速和风向变化越剧烈海洋环境极低频噪声与风速风向的相关性越好。 相似文献
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为探索南海某区域海洋环境噪声谱级与风场的相关特性,结合潜标海洋环境噪声数据及对应海域的海面风场再分析数据,计算各频段噪声级与风速相关系数及线性拟合函数。分析结果表明:400～1 000 Hz频段,海洋环境噪声谱级与海面风速的相关系数在0.5～0.8之间,达到中等相关。1 000～5 000 Hz频段,两者互相关系数大于0.8,达到高度相关。对海洋环境噪声谱级与对数风速的回归分析结果显示,1000～5 000 Hz频段,两者的线性函数关系显著;并且在1 000 Hz附近的拟合斜率最大,海洋环境噪声谱级对海面风速变化的灵敏度最高。 相似文献
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本研究利用亚洲海国际实验南海区所获取的海洋环境噪声数据,研究了2001年5月3日0时至5月17日0时海洋环境噪声的时频特性.实验期间有热带风暴西马仑经过,导致海面风速和风生海洋环境噪声随西马仑的逼近和远离出现了显著的升降.以1 250 Hz的海洋环境噪声为例,海洋环境噪声级在这一期间内有一个明显的升高、稳定和缓慢下降的过程.结合再分析风速数据研究海洋环境噪声级与风速的相关性,结果表明,在较高频1 250 Hz处,海洋环境噪声级与风速的互相关系数r为0.50;在较低频50~400 Hz处,两者的互相关系数r在-0.20~0.20之间.此外,本研究利用噪声级与对数风速之间的线性关系式,将海洋环境噪声级与实验过程中海面风速数据做回归分析,确定拟合系数,将此系数用于反演估计海面风速,反演误差在5%~20%之间. 相似文献
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针对环境噪声谱与多年前噪声谱已不同、非开阔海域环境噪声测量受限等问题,在南海某海域对环境噪声与风速进行了连续多年的观测,并对两者的关系进行了统计分析。文中首先介绍了海洋环境噪声的测量方法及风速数据的获取手段,然后针对环境噪声与风速的时变特性、相关系数进行分析,最后对比浅海与深海两种深度下环境噪声与风速相关性的差异。数据处理与分析结果表明,海洋环境噪声随风速的大小变化剧烈,7m接收深度的海洋环境噪声值与风速的相关性是所有接收深度中最好的,其中又以频率为2 000 Hz时最佳,并得到了海洋环境噪声与风速的回归拟合方程,此外浅海处环境噪声可能受到航行船舶的影响较多,浅海处环境噪声与风速的相关性明显小于深海处。 相似文献
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通过对2001年亚洲海国际声学实验(ASIAEX)得到的海洋环境噪声数据进行处理,计算了噪声场空间相关系数、功率谱密度和垂直指向性,分别研究了受到远距离和近距离船舶辐射噪声影响的海洋环境噪声空间相关性.结果表明:船舶距离较远(10 km)时其辐射噪声会导致500 Hz以下的海洋环境噪声的空间相关性提高,而对500 Hz以上噪声的空间相关性没有影响;船舶距离较近(≤10 km)时,船舶辐射噪声会导致500 Hz以下的海洋环境噪声相关系数振荡变化,噪声空间相关性曲线在噪声信号声程差相差四分之一波长时出现第一个零点,对500 Hz以上的海洋环境噪声则会引起噪声能量升高,噪声的空间相关性也相对提高.基于现有理论,分别讨论了远距离船舶和近距离船舶产生的噪声场声学特性,对两种噪声场的海洋环境噪声空间相关性进行了合理的解释. 相似文献
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近海风电场水下打桩辐射噪声特性测量分析 总被引：1，自引：0，他引：1
对滨海海上风电场一次完整的打桩过程不同水深处环境噪声进行监测和分析。结果表明:打桩过程水下辐射噪声脉冲信号,在所研究海域附近环境噪声级由原来打桩前的130 d B左右瞬间增加约20~50 d B,20~20 000 Hz频段,打桩噪声谱级高于工程前该海域背景环境噪声谱级约30~65 d B,100~1 000 Hz频率打桩辐射噪声谱级出现多个峰值,不同水深谱级最高峰值频率为200 Hz。根据打桩水下辐射噪声监测结果和浅海Marsh和Schulkin半经验公式,计算打桩辐射噪声声源级(距声源中心1 m处)为210.2 d B(参考声压1μPa)。为水下打桩辐射噪声的深入研究提供了基础数据,分析结果可供海洋环境和海洋生物保护研究参考。 相似文献
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星载微波散射计海面风场与海洋环境噪声的相关特性分析 总被引：2，自引：1，他引：1
根据海洋环境噪声机理及风关噪声已有的研究成果,提出利用星载微波散射计反演的海面风场数据进行海洋环境噪声分析,并对HY-2A和ASCAT数据与噪声谱级的相关性进行了对比分析。选取南海海域作为研究区,利用潜标测量系统获取的噪声数据和多源散射计风场数据开展了相关实验,并采用NCEP海面风场数据进行对比分析。结果表明,ASCAT数据与噪声的相关性优于HY-2A,散射计数据优于NCEP数据,散射计风场更适合海洋环境噪声的分析研究。该研究内容拓展了微波散射计风场数据的应用领域,并为海洋环境噪声研究提供了更好的技术手段。 相似文献
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近海海上风电场水下噪声传播模型适用性研究 总被引：1，自引：0，他引：1
通过现场采集近海海上风电场工程区运营期风机水下噪声和背景噪声数据,计算了噪声信号的倍频带声压级,功率谱级和峰值声压级,确定了海上风电场水下噪声总声源级为148.3 d B,以此开展近海海上风电工程风机水下噪声频域特性、功率密度谱特性等研究。在此基础上使用Kraken简正波模型和Bellhop射线模型对风电场运营期风机水下噪声在水平与垂直方向上的传播进行模拟,模拟了噪声在不同频带内的衰减程度,结果显示模型模拟结果在不同频率下的衰减趋势有着很大差异,产生了明显的多途干涉现象,通过实测数据对建立的噪声传播模型进行验证,发现Kraken简正波模型在500 Hz以下,Bellhop射线模型在500 Hz以上适合模拟实际水下噪声传播情形,同时海区本身背景噪声的存在会对预测的准确性产生影响。这些结论可用于进一步对近海海上风电场水下噪声传播的研究。 相似文献
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Measurements of the ambient-noise field between 50 and 300 Hz with vertical arrays at 32°N (124°W, 136°W, and 150°W) have been made. Substantial differences in the vertical distribution of noise have been measured (especially at the higher frequencies), which can be interpreted in the context of attenuation by seawater sound absorption of coastal shipping noise. Under low wind-speed conditions, the vertical distribution of ambient noise is clearly concentrated within approximately ±15° of the horizontal. High wind speed has the effect of filling in the higher vertical angles, while leaving the level within the low-angular region unchanged 相似文献
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The correlation of ambient noise with wind speed, and the depth dependence of ambient noise are both investigated, where the ocean noise data were recorded by a vertical line array in the northern South China Sea. It is shown that the correlation coefficients increase with increasing hydrophone depth during typhoon periods when the frequency ≥ 250 Hz, which opposes the generally accepted knowledge that the correlation coefficients of noise level and wind speed decrease with increasing depth during non-typhoon periods. Particularly at frequencies of 250 Hz, 315 Hz and 400 Hz, the correlation coefficients increase by more than 0.05 at depths ranging from 155 m to 875 m. At the three frequencies, the average noise levels also increase with increasing depth during typhoon periods. It is suggested that these differences are attributed to the wind-generated noise in shallow waters and the effect of "downslope enhancement" to sound propagation. During typhoon periods, the surf breaking and surf beat upon the shores and reefs are strengthened, and the source levels are increased. The wind-generated noise in shallow waters interacts with the downslope sea floor, with the noise-depth distribution changed by a "downslope enhancement" effect promoting noise propagation. 相似文献
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A buoy for measuring wind speed and the ambient noise sound pressure level from 10 to 1500 Hz with 1-Hz resolution is described. The measurement buoy was deployed in a remote fjord in southeastern Alaska from October to December, 1989. The results from the data collected show that, for a wind speed of 5 kn, the measured ambient noise level at 900 Hz lies well below the Knudsen curve for open-ocean, wind-generated noise. As the wind speed increases from 5 to 10 kn, the measured ambient noise level approaches the Knudsen curve, increasing at 4 dB/kn compared to 1 dB/kn for the Knudsen curve. Above 10 kn, the measured ambient noise level matches the Knudsen curve 相似文献
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Hotspots in ambient noise caused by ice-edge eddies in the Greenland and Barents Seas 总被引：1，自引：0，他引：1
Johannessen O.M. Sagen H. Sandven S. Stark K.V. 《Oceanic Engineering, IEEE Journal of》2003,28(2):212-228
Mesoscale eddies are frequently observed in the Greenland and Barents Seas' marginal ice zone (MIZ). The objective of this study was to investigate the hypothesis that acoustic hotspots along the ice-edge region are due to mesoscale eddy currents interacting with the broken-up ice floes in the MIZ. To test this hypothesis, ambient-noise case studies were carried out during the MIZEX 85-87 and SIZEX 89 field experiments. In each experiment, ice-edge eddies were localized visually from aircraft and by use of satellite remote-sensing data obtained in near real time. Sonobuoys were, thereafter, deployed by fix-wing aircraft and helicopters in selected eddy areas. Ambient-noise data, recorded over several hours by aircraft, were analyzed estimating averaged ambient-noise levels at four selected frequencies: 40, 100, 315, and 1000 Hz. The analysis showed high mean levels and large gradients in ambient noise near ice-edge eddies and during strong wind and wave forcing against the ice edge. The conclusion of this study is that mapping of the ice edge and localization of mesoscale ocean processes using remote sensing from space will provide important input to ambient-noise prediction in the MIZ. 相似文献
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Low-frequency ambient-noise measurements in the South Fiji basin 总被引：1，自引：0，他引：1
The effect of wind speed on ambient noise has been measured in an experiment carried out in the South Fiji basin. The noise data in the band 15-250 Hz are well correlated with the variations in the local wind speed. The relationship between noise level N and wind speed ν is expressed by N =B +20n log ν. The constants B and n have been estimated by fitting the data using this model. The analysis indicates that there are two types of behavior: for ν>15 kn, a value of n =1.5 is obtained for the entire band, whereas for ν<15 kn, there is no correlation with wind speed observed in the data. The results suggest that there is a delay of 40-120 min for the effect of wind on the hydrophone noise level 相似文献
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西沙北部海域海洋环境噪声频谱特性 总被引：2，自引：1，他引：1
Ambient noise is very important in the prediction system of a sonar performance, because it determines the detection ranges always in a passive sonar and usually in an active sonar. In the uncertainty issue for the so-nar performance, it is necessary to know this factor＇s statistical characteristics that are only obtained by data processing from the underwater ambient noise measurements. Broad-band ambient noise signals from 16 hydrophones were amplified and recorded for 2 min every 1 h. The results show that the ambient noise is essentially depth independent. The cross correlation of the ambient noise levels （1, 6 and 12 h average） with a wind speed is presented. It was found that the correlation is excellent on the upper frequency band and the noise levels correlate better with high wind speed than with low wind speed. 相似文献