Au W W, Pawloski J L, Nachtigall P E, Blonz M, Gisner R C
Hawaii Institute of Marine Biology, University of Hawaii, Kailua 96734, USA.
J Acoust Soc Am. 1995 Jul;98(1):51-9. doi: 10.1121/1.413643.
The echolocation transmission beam pattern of a false killer whale (Pseudorca crassidens) was measured in the vertical and horizontal planes. A vertical array of seven broadband miniature hydrophones was used to measure the beam pattern in the vertical plane and a horizontal array of the same hydrophones was used in the horizontal plane. The measurements were performed in the open waters of Kaneohe Bay, Oahu, Hawaii, while the whale performed a target discrimination task. Four types of signals, characterized by their frequency spectra, were measured. Type-1 signals had a single low-frequency peak at 40 +/- 9 kHz and a low-amplitude shoulder at high frequencies. Type-2 signals had a bimodal frequency characteristic with a primary peak at 46 +/- 7 kHz and a secondary peak at 88 +/- 13 kHz. Type-3 signals were also bimodal but with a primary peak at 100 +/- 7 kHz and a secondary peak at 49 +/- 9 kHz. Type-4 signals had a single high-frequency peak at 104 +/- 7 kHz. The center frequency of the signals were found to be linearly correlated to the peak-to-peak source level, increasing with increasing source level. The major axis of the vertical beam was directed slightly downward between 0 and -5 degrees, in contrast to the +5 to 10 degrees for Tursiops and Delphinapterus. The beam in the horizontal plane was directed forward between 0 degrees and -5 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)
在垂直平面和水平平面上测量了伪虎鲸（Pseudorca crassidens）的回声定位发射波束模式。使用由七个宽带微型水听器组成的垂直阵列在垂直平面上测量波束模式，在水平平面上则使用相同水听器组成的水平阵列。测量在夏威夷瓦胡岛卡内奥赫湾的开阔水域进行，同时该鲸鱼执行目标辨别任务。测量了四种以其频谱为特征的信号类型。1型信号在40±9千赫兹处有一个单一低频峰值，在高频处有一个低振幅波峰。2型信号具有双峰频率特征，主峰值在46±7千赫兹，次峰值在88±13千赫兹。3型信号也是双峰的，但主峰值在100±7千赫兹，次峰值在49±9千赫兹。4型信号在104±7千赫兹处有一个单一高频峰值。发现信号的中心频率与峰峰值源级呈线性相关，随源级增加而增加。垂直波束的主轴在0度至 -5度之间略微向下指向，这与宽吻海豚和白鲸的 +5度至10度相反。水平平面上的波束在0度至 -5度之间向前指向。（摘要截取自250字）
