CONTENTS

Policy on Intellectual Property Right (IPR)     ii
RECOMMENDATION  ITU-R  P.1812-1     1
A path-specific propagation prediction method for point-to-area terrestrial services in the VHF and UHF bands     1
Scope     1
Annex 1     2
1 Introduction  2
2 Model elements of the propagation prediction method  3
3 Input parameters  3
        3.1 Basic input data  3
        3.2 Terrain profile  3
        3.3     Radio-climatic zones  4
        3.4 Terminal distances from the coast 5
        3.5 Basic radio-meteorological parameters  5
        3.6 Incidence of ducting  5
        3.7 Effective Earth radius  6
        3.8 Parameters derived from the path profile analysis  6
4 The prediction procedure  6
        4.1 General 6
        4.2 Line-of-sight propagation (including short-term effects) 7
        4.3 Propagation by diffraction  8
                  4.3.1 Median diffraction loss  8
Median diffraction loss for the principal edge     8
Median diffraction loss for transmitter-side secondary edge     9
Median diffraction loss for the receiver-side secondary edge     10
Combination of the edge losses for median Earth curvature     10
                  4.3.2 The diffraction loss not exceeded for β₀% of the time  10
Principal edge diffraction loss not exceeded for β₀% time     11
Transmitter-side secondary edge diffraction loss not exceeded for β₀% time     11
Receiver-side secondary edge diffraction loss not exceeded for β₀% time     11
Combination of the edge losses not exceeded for β₀% time     12
                  4.3.3 The diffraction loss not exceeded for p% of the time  12
        4.4 Propagation by tropospheric scatter 12
        4.5 Propagation by ducting/layer reflection  13
        4.6 Basic transmission loss not exceeded for p% time and 50% locations ignoring the effects of terminal clutter     15
        4.7 Terminal clutter losses  17
        4.8 Location variability of losses  18
        4.9 Building entry loss  19
       4.10 Basic transmission loss not exceeded for p% time and p_L% locations  20
       4.11 The field strength exceeded for p% time and p_L% locations  21
Appendix 1 to Annex 1  Radio-meteorological data required for the prediction procedure     21
Appendix 2 to Annex 1  Path profile analysis     22
1 Introduction  22
2 Construction of path profile  23
3 Path length  24
4 Path classification  24
5 Derivation of parameters from the path profile  25
        5.1 All paths  25
                  5.1.1 Transmitting antenna horizon elevation angle, θ_t 25
                  5.1.2 Transmitting antenna horizon distance, d_lt 25
                  5.1.3 Receiving antenna horizon elevation angle, θ_r 26
                  5.1.4 Receiving antenna horizon distance, d_lr 26
                  5.1.5 Angular distance θ (mrad) 26
                  5.1.6 “Smooth-Earth” model and effective antenna heights  26
Appendix 3 to Annex 1  An approximation to the inverse complementary cumulative  normal distribution function     29