RECOMMENDATION ITU-R P.1812
A path-specific propagation prediction method for point-to-area
terrestrial services in the VHF and UHF bands 2
Scope
Annex 1
1 Introduction
2 Model elements
of the propagation prediction method
3 Input parameters
3.1
Basic input data
3.2
Terrain profile
3.3 Radio-climatic
zones
3.4
Terminal distances from the coast
3.5
Basic radio-meteorological parameters
3.6
Incidence of ducting
3.7
Effective Earth radius
3.8
Parameters derived from the path profile analysis
4 The prediction procedure 9
4.1 General
4.2
Line-of-sight propagation (including short-term effects)
4.3
Propagation by diffraction
4.3.1 Median diffraction
loss
Median diffraction loss for the principal edge
Median diffraction loss for transmitter-side secondary edge
Median diffraction loss for the receiver-side secondary edge
Combination of the edge losses for median Earth curvature
4.3.2 The diffraction
loss not exceeded for β0% of the time
Principal edge diffraction loss not exceeded for β0% time
Transmitter-side secondary edge diffraction loss not exceeded for β0%
time
Receiver-side secondary edge diffraction loss not exceeded for β0%
time
Combination of the edge losses not exceeded for β0% time
4.3.3 The diffraction
loss not exceeded for p%
of the time
4.4
Propagation by tropospheric scatter
4.5
Propagation by ducting/layer reflection
4.6
Basic transmission loss not exceeded for p% time and 50%
locations ignoring the effects of terminal clutter
4.7
Terminal clutter losses
4.8
Location variability of losses 20
4.9
Building entry loss
4.10
Basic transmission loss not exceeded for p% time and pL%
locations
4.11
The field strength exceeded for p% time and pL%
locations
Appendix 1 to Annex 1 Radio-meteorological data required for the
prediction procedure
Appendix 2 to Annex 1 Path profile analysis
1 Introduction
2 Construction of
path profile
3 Path length
4 Path
classification
5 Derivation of
parameters from the path profile
5.1
All paths
5.1.1 Transmitting
antenna horizon elevation angle, θt
5.1.2 Transmitting
antenna horizon distance, dlt
5.1.3 Receiving antenna
horizon elevation angle, θr
5.1.4 Receiving antenna
horizon distance, dlr
5.1.5 Angular distance θ (mrad)
5.1.6 “Smooth-Earth”
model and effective antenna heights
Appendix 3 to Annex 1 An approximation to the inverse
complementary cumulative normal distribution function