Outdoor Sound Propagation Modelling Across Scales with Uncertainties

拟议的项目设定了以下四个目标：1。研究用于模拟近、中、远距离室外声传播的气象、地面和其他环境数据的不确定性。2 .通过建模确定输入模型参数的不确定性对给定军事平台发出声音的模型预测精度的影响。3 .在一个室外声音传播通用建模工具（UMTOSP）中开发和集成多个传播模型，该工具在商定的范围内的尺度范围内是准确的。验证UMTOSP，并展示在计算一系列军事平台产生的声音方面的准确性和灵活性，以及在数据存在现实不确定性的情况下。这项工作将建立在声学传播模型的最新发展上。作为该项目的结果，将开发的新的通用模型将是用户友好的，它将能够在一个或多个位置的范围和高度上计算来自广泛来源的室外声音，在一个具有代表性的环境范围内，在不同的尺度下，在地面上，在低海拔和高海拔。该项目的这一部分将包括对不同传播模型的能力的详细调查，但是，为了规划该项目的目的，预计umtosp将基于：当地面阻抗效应占主导地位时，用于计算短距离声音传播的鲁棒分析模型（例如[4,5]）；基于能量的边界元方法，用于研究复杂地形和强地面阻抗效应（如[6]）下复杂源的中短距离声波传播；格林函数，或时域有限差分，抛物方程方法(如：[7,8])，在地形复杂的情况下，中远程传播受气象条件的影响。这样，模型应该包括在10到100米范围内观察到的影响，例如当地地形或建筑物的存在，在100到1000米范围内观察到的影响，例如地面阻抗，风力条件，以及在1000到10000米（甚至更多）范围内观察到的影响，例如温度和风廓线。这些模型（和通用模型）对输入数据不确定性的敏感性将使用贝叶斯方法（例如[9]）进行研究；这将使我们能够理解这些模型在输入不准确或时变的源、气象、地形和地面类型输入数据集时产生的计算误差。当在一个UMTOSP中组合时，这些模型将使我们能够（首次）在任何复杂的环境中计算声音传播，并在设定的精度限制和传播范围内使用最小数量的参数。项目的主要输出将是UMTOSP的软件代码，如果合适的话，可以用作战术决策辅助的基础。

The proposed project sets the following four objectives:1. To study the uncertainties in the meteorological, ground and other environmentdata which are used to model short, medium and long range outdoor soundpropagation.2. To determine through modelling the influence of uncertainty in the input modelparameters on the accuracy of the model predications for sounds emitted by agiven military platform.3. To develop and integrate several propagation models in one Universal ModellingTool for Outdoor Sound Propagation (UMTOSP) which is accurate over a range ofscales within the agreed bounds.4. To validate the UMTOSP and demonstrate the accuracy and flexibility in terms ofcalculating the sound resulting from a range of military platforms and in thepresence of realistic uncertainty in data.The work will be built on the latest developments in acoustic propagation modelling. Thenew universal model which will be developed as a result of the project will be user-friendlyand it will be able to calculate outdoor sound at one or more positions in range and heightfrom a broad range of sources, in a representative range of environments, at differentscales, on ground and at low and high altitudes.This part of the project will include a detailed investigation into the capabilities of differentpropagation models but, for the purposes of planning the project it is expected that theUMTOSP is based on:i. robust analytical models (e.g. [4,5]) to calculate short range sound propagationwhen the ground impedance effect is dominant;ii. energy-based boundary element methods to study short and middle rangesound propagation from complex sources and in the presence of complexterrain and strong ground impedance effects (e.g. [6]);iii. green's function, or time domain finite differences, parabolic equation methods(e.g. [7,8]) when medium and long range propagation in the presence ofcomplex terrain is affected by the meteorological conditions.In this way, the models should include effects observed at short range, 10s to 100s ofmetres, such as the presence of local topography or buildings, medium range, 100s to 1000s of metres, such as ground impedance, wind conditions, and long range, 1000s to10,000s (and more) of metres, such as temperature and wind profile.The sensitivity of these models (and the universal model) to the uncertainties in the inputdata will be studied using the Bayesian approach (e.g. [9]); this will enable us tounderstand the errors in the calculations these models produce when inaccurate or timevariantsets of source, meteorological, topographical and ground type input data are inputfor a given source / receiver geometry.When combined in one UMTOSP these models will enable us to calculate soundpropagation (for the first time) in an environment of any complexity and with a minimumnumber of parameters within the set accuracy limits and propagation ranges.The main output from the project would be software code for the UMTOSP that could, ifappropriate, be used as the basis for a tactical decision aid.