海下目標搜索與偵測之模擬與分析研究

聲波仍是水下唯一可以遠程傳遞能量的形式，可以用來偵測海下目標，然而聲波在海中傳播的能量、速度與角度，會隨著時間、空間而變化，因而增加應用的困難度。研究水下聲學雖源自於偵測潛水艇的軍事需求，然而目前已廣泛應用於海下目標偵測，包含水中生物探測、海洋物理探測、鯨豚監測、海洋環境監測等用途，本論文以水下聲學監測為基礎，置重點於海下目標搜索的模擬與分析。水下聲學在軍事上的用途主要是運用於反潛作戰，反潛作戰包含水面艦艇、直升機對潛艇的搜索、定位與攻擊。本研究探討了水下偵測設備的種類、發展與搜索的應用，並針對濱海區域，建立蒙地卡羅模擬模式，發展戰術階層想定，重複模擬求算大洋反潛作戰使用的距離獨立(RI)與濱海所用的距離相依(RD)兩種聲納預測模式之作戰效益數據，經1000次的模擬運算，以嚴謹的ANOVA分析，發現不同聲納預測法、潛艦速率、偵測機率之間都具有極大的差異。另外本研究也分析了南海海域在不同時空下的聲納偵測效能，提出了南海聲納探測效能的模擬結果，顯示在秋、夜間和淺水區，聲納的偵測效能表現較好。在海下生物目標搜索與偵測方面，本論文以台灣西海岸瀕臨絕種的中華白海豚族群為研究標的，在大甲溪至大肚溪之間的台中港近海佈放了6個固定的水下聲學監測站，對活動的白海豚進行大範圍的水下聲學量測，藉由統計whistles 及clicks的結果，能初步分析白海豚在該海域活動之狀況。目前主要使用於調查白海豚族群數量的方法是海上目視搜索，然而這種方法受限於天候、人力等限制。使用被動式聲學監測可以輔助目視觀察的不足，在能見度低的時間也能夠蒐集到鯨豚活動的資料。為改良海上目視搜索法，本研究提出了水下聽音器以物聯網與無人機結合的新的監測機制。水下聽音器在偵獲白海豚時，將呼叫無人機前來攝影識別，經過蒙地卡羅的模擬結果顯示，新的機制在操作中的可用性提高了8.5倍，並且接觸的次數至少是海上目視調查法的2倍，是一種有效的搜索與偵測機制。

關鍵字

搜索與偵測；水中聲學；聲納效能；模式模擬；反潛作戰；中華白海豚；物聯網

並列摘要

Sound waves are still the only underwater energy that can be transmitted remotely for detecting the undersea targets. However, the energy, speed and path of sound propagating in the sea are changed in terns of time and space, which would increase the difficulty of implementation. Although the study of underwater acoustics originated from the military requirements of detecting submarines, it has been widely used in aquatic life detection, marine physical detection, cetacean monitoring, marine environmental monitoring and other livelihood applications. The objective of this dissertation is to use models and simulation for getting insight of underwater operations in terns of search, detection and monitoring. The military use of underwater acoustics is mainly in the anti-submarine warfare. Anti-submarine warfare includes the search, location and attack on submarines from surface ships or helicopters. In study, in order to evaluate explores the development and effectiveness of equipments, a Monte Carlo simulation model was developed, to calculate the efficiency of sonar prediction methods. Range independent (RI) mode used by the open ocean anti-submarine warfare and the range dependent (RD) mode used by the coastal. That they were evaluated for the best interest to the coastal ASW. After 1000 runs simulation and with a rigorous ANOVA analysis, is a significant differences between this two sonar prediction methods in terns of submarine speed, and detection probability. In addition, this study also analyze the sonar detection performance of the South China Sea in different time and space, and proposed the simulation results of the South China Sea sonar detection performance, showing that the sonar detection performance is better in autumn, night and shallow water. In searching and dectection of marine mammal, this study also got to look at the issue of the endangered Chinese white dolphin population on the west coast of Taiwan. There are six fixed underwater acoustic monitoring stations were deployed near the Taichung Harbor between Dajia river and Dadu river. This is a large-scale underwater acoustic monitoring system for the moving white dolphins in this area, the aim is to measure dolphin’s whistles and clicks. As a result, the status of the activity of the white dolphins in this waters is initially analyzed. On the other hand, the current method used to investigate the number of white dolphin population is the maritime visual search method. However, this method is limited by weather, manpower and other restrictions. Passive acoustic monitoring can be used to assist visual observations, and sounds on cetacean behaviors can be collected at low visibility times. In order to improve the maritime visual survey method, this study proposed a new monitoring mechanism for the hydrophone to combine the Internet of Things with the UAV. Once the hydrophone detects the white dolphin, the system would call the UAV for flying over the targeted area for the search and recognition. After the analyses of Monte Carlo simulation, the availability of the new mechanism is increased by 8.5 times in operation, and the number of contacts is at least 2 times to the visual survey method at sea. The result showed that this hydrophone and UAV mechanism is very effective in monirting the sea animal in terns of a specific task.

並列關鍵字

search and detection ； underwater acoustic ； sonar detection performance ； modeling simulation ； ASW warfare ； Chinese white dolphin ； IoT

參考文獻

[1] Wood A. B. (1965), From the Board of Invention and Research to the Royal Naval Scientific Service, Journal of the Royal Naval Scientific Service, Vol 20, No 4, pp 1–100 (185–284).