Barrier Reflection Loss

**Strutt|Environmental Noise|Barrier Reflection loss** provides a calculation for the angle-dependant reflection loss of a barrier with a rough surface. To be used for calculating the effect of barrier reflections. Uses equations provided in Nord2000.

The calculation assumes the surface is hard or almost hard with a rough texture of random nature.

The reflection coefficient, `\rho_E` is calculated as:

`\rho_E = exp(-2(k\sigma cos(\theta))^2)`

Where,

`k` is the wave number,

`\sigma` is the rms-value of the depth of the random irregularities in the texture. This can be approximated as 0.3 times the peak to peak irregularities,

`\theta` is the angle of incidence.

The reflection loss is then calculated by:

`\Delta L_r = 10 log(\rho_E)`

References:

- Nord2000. Comprehensive Outdoor Sound Propagation Model. Part 1: Propagation in an Atmosphere without Significant Refraction, p100-101

Comments or suggestions to strutt@arup.com