【摘要】：北極水聲學的研究是聲學研究的熱點之一。本文利用中國第六次北極科學考察的數(shù)據(jù)資料,對北冰洋太平洋扇區(qū)的聲學體積后向散射強度以及海洋環(huán)境噪聲進行重點研究。論文主要包括以下五個方面的內容:(1)利用下放式聲學多普勒測流儀(LADCP)數(shù)據(jù)分析白令海水下聲體積后向散射強度,發(fā)現(xiàn)白令海深散射層生物的晝夜遷移現(xiàn)象。深層水體積后向散射強度在1800m處有一個極大值區(qū)。(2)加拿大海盆海冰邊緣區(qū)是聲體積后向散射強度的明顯過渡區(qū)。無冰海面(海冰密集度小于15%)的海洋深層水的聲體積后向散射強度明顯大于密集海冰區(qū)域的海水(海冰密集度大于50%)。討論了聲體積后向散射強度與海冰融化之間的關系,造成融冰區(qū)聲體積后向散射強度增大的原因是水下懸浮泥沙、浮游生物等懸浮物質增加。根據(jù)海冰密集海域的海水后向散射強度弱的特點,對北極下放式聲學多普勒測流儀(LADCP)觀測的設置提出建議。(3)楚科奇海臺范圍內150m以淺的海水體積后向散射強度強于海臺周圍,對這種差異原因進行解釋。在極晝期間,150m以淺的聲散射層垂直遷移與當?shù)靥柛叨冉怯嘘P。(4)對北冰洋太平洋扇區(qū)的深散射層生物發(fā)聲進行研究,發(fā)現(xiàn)此區(qū)域深散射層生物發(fā)聲頻率集中在2000-3000Hz之間。(5)利用變閾值小波變換濾波法對SBE-911CTD配套梅花采水器10L懫水瓶的懫水信號進行提取,并分析懫水聲信號的時頻特性,懫水時域信號由激發(fā)彈扣信號與懫水瓶閉合信號組成;頻域信號有雙峰結構,峰值分別出現(xiàn)在750Hz與2300Hz,雙峰結構的明顯程度與時域信號脈沖數(shù)量有關。
[Abstract]:The study of Arctic underwater acoustics is one of the hot spots in acoustics research. Based on the data of the sixth Arctic Scientific Survey in China, the acoustic volume backscattering intensity and the environmental noise of the Arctic Ocean sector are studied in this paper. The main contents of this paper are as follows: (1) by using the (LADCP) data of the acoustic Doppler current meter, the backscattering intensity of underwater acoustic volume in Bering Sea is analyzed, and the diurnal migration of organisms in the deep scattering layer in Bering Sea is found. The backscatter intensity of deep water volume has a maximum at 1800 m. (2) the edge of sea ice in the Canadian basin is an obvious transition area of the backscattering intensity of acoustic volume. The sound volume backscattering intensity of deep sea water without sea ice (sea ice density less than 15%) is obviously higher than that of sea water in dense sea ice area (sea ice density is more than 50%). The relationship between the backscattering intensity of acoustic volume and the melting of sea ice is discussed. The reason for the increase of backscattering intensity of acoustic volume in melting ice area is the increase of suspended sediment and plankton. According to the weak backscattering intensity of sea water in the sea ice dense area, Some suggestions for setting up the (LADCP) observations of the arctic acoustic Doppler current meter are given. (3) the backscatter intensity of 150 m in shallow seawater volume is stronger than that around the sea station in the range of 150 m in the Chukchi sea station. The reasons for this difference are explained. During polar day, the vertical migration of 150m in a shallow acoustic scattering layer is related to the local solar height angle. (4) the acoustic sounding in the deep scattering layer in the Arctic Pacific sector is studied. It is found that the frequency of biological sound in the deep scattering layer in this area is between 2000-3000Hz. (5) using the variable threshold wavelet transform filter to extract the water signal from the 10L water bottle of the SBE-911CTD matching plum-blossom water collector. The time-frequency characteristic of the acoustic signal is analyzed. The time-domain signal is composed of the exciting elastic clasp signal and the closing signal of the water bottle. The frequency domain signals have bimodal structure, the peaks occur in 750Hz and 2300Hz, respectively. The obvious degree of bimodal structure is related to the number of time-domain signal pulses.
【學位授予單位】：國家海洋局第一海洋研究所
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P733.2

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相關博士學位論文 前1條

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