Radio propagation for vehicular communications

Radio propagation is affected by many factors including the frequency, distance, antenna heights, curvature of the earth, atmospheric conditions, and the presence of hills and buildings. The influence of each of these factors at frequencies above about 30 MHz is discussed with most of the quantitative data being presented in the series of nomograms. By means of three or four of these charts an estimate of the received power and the received field intensity for a given point-to-point radio transmission path ordinarily can be obtained in a minute or less. The theory of propagation over a smooth spherical earth is presented in a simplified form that is made possible by restricting the frequency range to above about 30 MHz where variations in the electrical constants of the earth have only a secondary effect. The empirical methods used in estimating the effects of hills and buildings and of atmospheric refraction are compared with experimental data on shadow losses and on fading ranges.

[1]  E. B. Ferrell,et al.  Ultra-Short-Wave Propagation , 1933, Proceedings of the Institute of Radio Engineers.

[2]  K. Norton,et al.  The Propagation of Radio Waves over the Surface of the Earth and in the Upper Atmosphere , 1937, Proceedings of the Institute of Radio Engineers.

[3]  C. Burrows,et al.  Radio propagation over plane earth — Field strength curves , 1937 .

[4]  K. Norton,et al.  The Calculation of Ground-Wave Field Intensity over a Finitely Conducting Spherical Earth , 1941, Proceedings of the IRE.

[5]  The Effect of the Earth's Curvature on Ground-Wave Propagation , 1941, Proceedings of the IRE.

[6]  H.T. Friis,et al.  Noise Figures of Radio Receivers , 1944, Proceedings of the IRE.

[7]  E. W. Allen.  Very-High-Frequency and Ultra-High-Frequency Signal Ranges as Limited by Noise and Co-channel Interference , 1947, Proceedings of the IRE.

[8]  K. Bullington,et al.  Radio Propagation Variations at VHF and UHF , 1950, Proceedings of the IRE.

[9]  Jr. W.R. Young,et al.  Comparison of mobile radio transmission at 150, 450, 900, and 3700 mc , 1952 .

[10]  J. W. Herbstreit,et al.  Large Reductions of VHF Transmission Loss and Fading by the Presence of a Mountain Obstacle in Beyond-Line-of-Sight Paths , 1953, Proceedings of the IRE.

[11]  Kenneth Bullington,et al.  Radio Transmission beyond the Horizon in the 40-to 4,000-MC Band , 1953, Proceedings of the IRE.

[12]  Jr. W.R. Young.  Comparison of mobile radio transmission at 150, 450, 900, and 3700 mc , 1953 .

[13]  P. L. Rice,et al.  The Use of Angular Distance in Estimating Transmission Loss and Fading Range for Propagation through a Turbulent Atmosphere over Irregular Terrain , 1955, Proceedings of the IRE.

[14]  K. Bullington,et al.  Results of Propagation Tests at 505 mc and 4,090 mc on Beyond-Horizon Paths , 1955 .

[15]  Kenneth Bullington,et al.  Characteristics of Beyond-the-Horizon Radio Transmission , 1955, Proceedings of the IRE.

[16]  W. H. Tidd.  Demonstration of Bandwidth Capabilities of Beyond-Horizon Tropospheric Radio Propagation , 1955, Proceedings of the IRE.

[17]  Kenneth Bullington.  Characteristics of beyond-the-horizon radio transmission , 1955 .

[18]  K. Bullington,et al.  Results of Propagation Tests at 505 mc and 4,090 mc on Beyond-Horizon Paths , 1955, Proceedings of the IRE.

[19]  J. Debettencourt,et al.  Theory of Radio Transmission by Tropospheric Scattering Using Very Narrow Beams , 1955, Proceedings of the IRE.

[20]  William E. Gordon,et al.  Radio Scattering in the Troposphere , 1955, Proceedings of the IRE.