Ostashev Vladimir E, Scanlon Michael V, Wilson D Keith, Vecherin Sergey N
NOAA/Earth System Research Laboratory, Boulder, Colorado 80303, USA.
J Acoust Soc Am. 2008 Dec;124(6):3413-20. doi: 10.1121/1.3003085.
Localization of sound sources on the ground from an acoustic sensor array elevated on a tethered aerostat is considered. To improve estimation of the source coordinates, one should take into account refraction of sound rays due to atmospheric stratification. Using a geometrical acoustics approximation for a stratified moving medium, formulas for the source coordinates are derived that account for sound refraction. The source coordinates are expressed in terms of the direction of sound propagation as measured by the sensor array, its coordinates, and the vertical profiles of temperature and wind velocity. Employing these formulas and typical temperature and wind velocity profiles in the atmosphere, it is shown numerically that sound refraction is important for accurate predictions of the source coordinates. Furthermore, it is shown that the effective sound speed approximation, which is widely used in atmospheric acoustics, fails to correctly predict the source coordinates if the grazing angle of sound propagation is relatively large.
考虑通过系留气球上的声学传感器阵列对地面声源进行定位。为了改进声源坐标的估计，应考虑由于大气分层导致的声线折射。利用分层运动介质的几何声学近似，推导了考虑声折射的声源坐标公式。声源坐标根据传感器阵列测量的声传播方向、其坐标以及温度和风速的垂直剖面来表示。利用这些公式以及大气中的典型温度和风速剖面，通过数值计算表明声折射对于声源坐标的准确预测很重要。此外，结果表明，如果声传播的掠射角相对较大，大气声学中广泛使用的有效声速近似无法正确预测声源坐标。
