RECOMMENDATION ITU-R P.452-10 - Prediction procedure for the evaluation of microwave ... ANNEX 1 1 Introduction 2 Interference propagation mechanisms 3 Clear-air interference prediction 3.1 General comments 3.2 Deriving a prediction 4 Clear-air propagation models 4.1 General 4.2 Line-of-sight propagation (including short-term effects) 4.3 Diffraction 4.4 Tropospheric scatter (Notes 1 and 2) 4.5 Ducting/layer reflection 4.6 Additional clutter losses 4.7 Calculation of transmission loss 5 Hydrometeor-scatter interference prediction 5.1 Introduction 5.2 Transmission loss formula 5.3 Cumulative distribution of transmission loss 5.4 Worst-month predictions APPENDIX 1 TO ANNEX 1- Radio-meteorological data required for the clear-air prediction procedure 1 Introduction 2 Maps of vertical variation of radio refractivity data 3 Map of surface refractivity, N0 4 Implementation of maps in computer database form APPENDIX 2 TO ANNEX 1 - Path profile analysis 1 Introduction 2 Construction of path profile 3 Path length 4 Path classification 4.1 Classification Step 1: Test for a trans-horizon path 4.2 Step 2: Test for line-of-sight with sub-path diffraction (i.e. without full first Fresnel zone clearance) 5 Derivation of parameters from the path profile 5.1 Trans-horizon paths APPENDIX 3 TO ANNEX 1 - Physical basis of the hydrometeor-scatter model APPENDIX 4 TO ANNEX 1 - An approximation to the inverse cumulative normal distribution function for x ( 0.5