Abstract：
Echolocating bats are known to vary their waveforms at the phases of searching, approaching, and capturing the prey. It is meaningful to estimate the parameters of the calls for bat species identification and the technological improvements of the synthetic systems, such as radar and sonar. The type of bat calls is species-related, and many calls can be modeled as hyperbolic frequency- modulated (HFM) signals. To obtain the parameters of the HFM-modeled bat calls, a reversible integral transform, i.e., hyperbolic scale transform (HST), is proposed to transform a call into two-dimensional peaks in the \"delay-scale\" domain, based on which harmonic separation and parameter estimation are realized. Compared with the methods based on time-frequency analysis, the HST-based method does not need to extract the instantaneous frequency of the bat calls, only searching for peaks. The verification results show that the HST is suitable for analyzing the HFM-modeled bat calls containing multiple harmonics with a large energy difference, and the estimated parameters imply that the use of the waveforms from the searching phase to the capturing phase is beneficial to reduce the ranging bias, and the trends in parameters may be useful for bat species identification.
摘要：
众所周知，定位蝙蝠会在搜索阶段改变其波形，接近,捕获猎物。估计蝙蝠物种识别的呼吁参数和合成系统的技术改进是有意义的，比如雷达和声纳。蝙蝠叫声的类型与物种有关，并且许多呼叫可以被建模为双曲调频(HFM)信号。要获得HFM建模的蝙蝠呼叫的参数，可逆积分变换,即，双曲尺度变换(HST)，建议将呼叫转换为“延迟标度”域中的二维峰值，在此基础上实现了谐波分离和参数估计。与基于时频分析的方法相比，基于HST的方法不需要提取蝙蝠叫声的瞬时频率，只寻找山峰。验证结果表明，HST适用于分析HFM建模的蝙蝠叫声包含多个谐波，具有较大的能量差，和估计的参数意味着使用从搜索阶段到捕获阶段的波形有利于减少测距偏差，参数的趋势可能对蝙蝠物种识别有用。
