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.

Olive Tree Lab Terrain bases its strengths on its powerful ray tracing/ ray detection engine.  In contrast with traditional ray tracing methods, Olive Tree Lab Terrain uses an in-house developed engine which combines speed from the latest algorithms in ray detection and ray tracing alongside with the accuracy of established approaches in ray tracing like the image source method.

Noise prediction calculation in Olive Tree Lab Terrain takes into account geometrical spreading, atmospheric absorption, atmospheric turbulence, spherical wave complex ground impedance, reflection and diffraction effects of natural or man-made objects.

Olive Tree Lab Terrain displays the results as level vs frequency or level vs spatial mapping.

OTL Terrain is an acoustic calculations application based on the following methods and their limitations (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

In this version no atmospheric refraction calculations are included.

Based on state of the art calculation methods which demand computational power and time, Olive Tree Lab Terrain  is aimed for noise mapping for small and medium scale projects as opposed to large noise mapping software. It addresses mostly fixed noise sources within a small area where one has control over most of the parameters involved in the calculations. 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.

Calculations based on the following:

• Currently implementing the final part of ISO 9613, to be released in the next update version 1.4
• Atmospheric absorption based on ISO 9613 -1.
• Hadden & Pierce Diffraction 3D model implemented with finite impedances faces using Salo-mons semi-analytical method including ground effects. Multiple barrier diffraction is calculated in a recursive way at any diffraction order.
• 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 contribu-tion at any order level.
• Turbulence coherence factor based on HARMONOISE WP3
• Ray Tracing and Ray Detection engine – sophisticated in-house detection engine that can detect sound rays in complex 3D environments

• Multiple Noise Sources
• Noise Source Database. Also manual input of sound measurements or other data
• Line Source & Point Source
• Sound Power Level in 1/3 Octave Bands - 25 Hz to 10,000 Hz
• Sound Pressure Level 1/3 Octave Bands - 25 Hz to 10,000 Hz

• Multiple Receivers
• Receiver Noise Criteria Database. Also manual input of sound measurements or other data

• Noise barriers of finite size with special properties for the design of remedial measures. At a click of a button one can change from a wedge barrier to an I-shape, Γ-shape or Π-shape barrier thin or thick
• Barrier surface type from database or manual input of data
• Multiple barrier diffraction is calculated in a recursive way at any diffraction order

• Maximum diffraction order up to 3 on barriers and 2 on walls
• Maximum Reflection order up to 5
• Maximum ray length 10,000m

• According to the accuracy of the theoretical models used. Indicative range of +/-2 dB(A) up to 500m

• Spatial sound level distribution – Noise mapping displaying results in terms of spatial sound level distribution. Multiple areas may be selected by the user. Noise Levels are displayed in 1/3 octave bands centre frequencies or overall levels in dB(A). Results comparison with noise criteria show in colour areas complying or not with project noise criteria
• Frequency Analysis - spectrum results can be displayed within any frequen-cy range with a constant bandwidth or constant percentage bandwidth fre-quency analysis or both. At any switch-over frequency value one may apply a different frequency analysis method. Results are at the same time displayed in 1/3 (25 – 10000Hz) and 1/1 (31 – 8000 Hz) octave bands after being processed from the high resolution frequency analysis
• Excess Level Meter, indicates in red, orange and green colours how close to a solution the design process is. It checks whether a source, receiver, barrier and ground configuration within a 3D model, meet project noise criteria.
• Indicative Graph - Runs calculations in 1/3 octave centre frequencies only, displaying results in octave bands. It checks whether solutions meet noise crite-ria. The Indicative calculations take into account only the (a) Noise Source/s, (b) Receiver, (c) Barrier and (d) Ground/s and disregards everything else in the 3D model.
• Real-time indicative results are given in real time whenever any parameter is changed or object is moved.
• Precise Graph - Results are shown in 1/1 octave bands after being appro-priately processed from higher frequency resolution results (also shown in Out-put Window)
• Results can be exported to the clipboard, in .txt or .csv file formats
• Screenshots exported to Report or Clipboard
• Output Window result curves and 3D mapping show:
  • Level Before: the noise source level at the receiver before the imple-mentation of a barrier.
  • Level After: the noise source level at the receiver after the imple-mentation of a barrier.
  • IL: Insertion Loss (Level After - Level Before). This is the effect felt at the receiver by the implementation of a barrier. By definition this is a negative value and that is how it is shown in the Output Window, however, in the Precise and Indicative Results, IL is shown as a posi-tive quantity.
  • BEA: Barrier Excess Attenuation
  • Noise Criteria applied at the receiver.
  • Excess Noise Levels: The level exceeding the Noise Criteria (graphs in values, mapping in colour).

• Import/Export to DXF/DWG
• No limitations on number of surfaces OTL Terrain can handle, it depends on PCs memory

• Windows XP, Windows Vista, Windows 7, Windows Server 2003, Windows Server 2008, Windows Server 2008 R2 (Required)
• .Net Framework 4.0 (Required)
• 100MB hard disk (Required)
• Dual Core or better processor (Recommended)
• Graphics Card with Direct X 10 and above (Recommended)