Olive Tree Lab Terrain® is an acoustics software application that can be used for noise barrier design and for mapping small to medium scale projects. Olive Tree Lab Terrain® covers the need of acoustic engineers for a noise barriers design tool. The application is focused on two main pillars, accuracy and ease of use.
Sound Path Explorer (SPE)
The Sound Path Explorer, is a module used by OTL-Terrain, an in-house developed algorithm to detect valid diffraction and reflection sound paths from source to receiver in a proper 3D environment.
Sound Propagation Calculation
Mediterranean Acoustics Research & Development, has created an acoustical calculation engine which simulates sound propagation in a three dimensional environment with a possibility of eventually including all phenomena deemed important in acoustics. It utilises the principle of sound rays to detect sound paths. Currently a sound ray in OTL-Terrain, carries information on how to lose intensity with distance, how to interact with the atmosphere and how to reflect and diffract when it encounters objects. Eventually the sound ray will acquire sound transmission and refraction properties, thus the acoustical model would be able to analyse phenomena combining outdoor sound propagation, sound transmission and room acoustics at the same time.
OTL Terrain is based on the following methods and their limitations (Please see Reference List):
- Hadden & Pierce Diffraction 3D model implemented with finite impedances faces using Salomons semi-analytical method including ground effects. Multiple barrier diffraction is calculated in a recursive way at any diffraction order.
- In-house sound path detection methods.
- Ground effect using the One Parameter Theory of Chessell based on Delany and Bazley.
- Reflections from finite surfaces based on Clay–Medwin’s work to include Fresnel zones contribution at any order level.
- Atmospheric absorption based on ISO 9613 -1.
- Turbulence coherence factor based on HARMONOISE WP3
- Includes ISO 9613-2 calculation methods (equivalent to ANSI S12.62-201x standard, which will soon be adopted in the USA.)
Based on state of the art calculation methods it is based on high frequency resolution calculations, as opposed to just 1/3 octave band analysis, which can also be seen in 1/3 and 1/1 octave bands after being appropriately averaged. Olive Tree Lab Terrain can be used for acoustic engineering, acoustic research and educational purposes.
Olive Tree Lab-Terrain displays the results as level vs frequency or level vs spatial mapping.
- Impulse Response
- Auralisation in mono
- Isolines in mapping
- User adjusted interpolation in mapping
- User adjusted legend steps in mapping
- Improved 3D representation for multiple mapping areas
- Export of mapping results to clipboard
- Absorption coefficients have been added for walls, grounds and barriers
- Flow resistivity values can now be converted to absorption coefficients
- Unlimited reflections and diffractions
- Calculation of selected paths contribution in the frequency and time domains
- Other features