Abstract
Abstract. Prediction of outdoor sound levels in 3D space is important for noise management, soundscaping etc. Sound levels at outdoor can be predicted using sound propagation models which need terrain parameters. The existing practices of incorporating terrain parameters into models are often limited due to inadequate data or inability to determine accurate sound transmission paths through a terrain. This leads to poor accuracy in modelling. LIDAR data and Aerial Photograph (or Satellite Images) provide opportunity to incorporate high resolution data into sound models. To realize this, identification of building and other objects and their use for extraction of terrain parameters are fundamental. However, development of a suitable technique, to incorporate terrain parameters from classified LIDAR data and Aerial Photograph, for sound modelling is a challenge. Determination of terrain parameters along various transmission paths of sound from sound source to a receiver becomes very complex in an urban environment due to the presence of varied and complex urban features. This paper presents a technique to identify the principal paths through which sound transmits from source to receiver. Further, the identified principal paths are incorporated inside the sound model for sound prediction. Techniques based on plane cutting and line tracing are developed for determining principal paths and terrain parameters, which use various information, e.g., building corner and edges, triangulated ground, tree points and locations of source and receiver. The techniques developed are validated through a field experiment. Finally efficacy of the proposed technique is demonstrated by developing a noise map for a test site.
Highlights
Prediction of sound level is important for managing noise pollution, urban planning, sound barrier design, 3D virtual realization of sound, etc
A sound model needs various terrain parameters related to different paths of transmission of sound, viz. distance between source and the receiver, the length of path difference in case sound reaches the receiver after diffraction, angle and coefficient of reflection for the sound reflecting from ground or walls, and the length of transmission through trees
The shortfalls of modelling can be overcome by the input of accurate terrain parameters corresponding to detailed transmission paths after extracting these from high resolution 3D terrain data e.g., LIDAR data and Aerial Photograph
Summary
Prediction of sound level is important for managing noise pollution, urban planning, sound barrier design, 3D virtual realization of sound, etc. The shortfalls of modelling can be overcome by the input of accurate terrain parameters corresponding to detailed transmission paths after extracting these from high resolution 3D terrain data e.g., LIDAR data and Aerial Photograph. There is no reported technique to extract terrain parameters from classified high resolution remotely sensed data The determination of these terrain parameters becomes very difficult for urban environment due to the complexities of building and other over ground objects. Among all paths the shortest path termed as principal path make important contribution for prediction of sound at the receiver location (Bies, et al, 2003) These paths are required to be determined to find related terrain parameters that are needed for prediction of sound at different locations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
