Division Calculation of the term Δ ground(O,R)

where

• A_{ground (O,R)} is the attenuation due to the ground effect between the diffraction point O and the receiver R. This term is calculated as indicated in the previous subsection on calculation in homogeneous conditions and in the previous subsection on calculation in favourable conditions, with the following hypotheses:

  z_s = z_o,r

• G_path is calculated between O and R.

The G′_path correction does not need to be taken into account here as the source considered is the diffraction point. Therefore, G_path shall indeed be used in the calculation of ground effects, including for the lower bound term of the equation which becomes – 3(1 – G_path ).

• In homogeneous conditions, Ḡ_w = G_path in equation (2.5.17) and Ḡ_m = G_path in equation (2.5.18);

• In favourable conditions, Ḡ_w = G_path in equation (2.5.17) and Ḡ_m = G_path in equation (2.5.20);

• Δ _dif(S,R′) is the attenuation due to the diffraction between S and the image receiver R′, calculated as in the previous section on pure diffraction;

• Δ _dif(S,R) is the attenuation due to the diffraction between S and R, calculated as in the previous subsection on pure diffraction.