A17.9.3 Input Parameters

In order to make correctly calculations using the Longley-Rice propagation, model should take into account a number of input parameters describing the weather phenomena, system parameters, sitting criteria, statistical criteria which was shown in the table below.

Figure 476: GUI of the Longley Rice

Table 91: Longley Rice propagation model

Description	Symbol	Type	Unit	Comments
Variation	-	Boolean	-	Variation in path loss takes into account the uncertainty of building design, furniture, room size, etc.
Mean surface refractivity (Ground refractivity)	-	Scalar	Ns	Equatorial Continental Subtropical Maritime Subtropical Desert Continental Temperate Maritime Temperate over land Maritime Temperate over sea	360 320 370 280 301 320 350
Terrain irregularity parameter	-	Scalar	M	Flat Plains Hills Mountains Rugged mountains	0 30 90 200 500
Electrical ground Conductivity	-	Scalar	S/m	Average ground Poor ground Good ground Fresh water Sea water	0.005 0.001 0.020 0.010 5
Relative permittivity	-	Scalar		Average ground Poor ground Good ground Fresh water Sea water	15 4 25 81 81
Polarisation	-	List	-	0 – horizontal, 1- vertical
Site Criteria	-	List	-	Random, Careful, Very Careful
Radio climate	-	List	-	Equatorial Continental Subtropical Maritime Subtropical Desert Continental Temperate Maritime Temperate over land Maritime Temperate over sea
Time percentage	-	Distribution or Scalar	%	0.01 – 0.99
Location percentage	-	Distribution or Scalar	%	0.01 – 0.99
Confidence level	-	Distribution or Scalar	%	0.01 – 0.99
Mode of variability	-	List	-	Single, individual, broadcast
Standard deviation	Std. dev.	Scalar	dB