page_title: Two-ray ground-reflection model
section_title: Power vs. distance characteristics
hierarchical_section_title: Two-ray ground-reflection model / Power vs. distance characteristics
caption_attribution_description: English: This plot is generated using the matlab/octave script ld=0:0.001:5; d=10.^ld; ht=50; hr=2; l_gr=sqrt( (ht+hr)^2+d.^2); l_los=sqrt( (ht-hr)^2+d.^2); R=-1; G_los=1; G_gr=1; lambda=1/3; phi=2*pi*(l_gr-l_los)/lambda; los=sqrt(G_los)./l_los; gr=R*sqrt(G_gr)*exp(-j.*phi)./l_gr; rs=lambda.*(los+gr)/4*pi; ps=abs(rs).^2; norm=ps(1); pn=ps./norm; x = ld; y =10*log10(pn); plot(ld,y); title('Power vs distance plot for 2-ray ground reflected model '); xlabel('log(d)'); ylabel('Normalized Power(in dB)'); print -deps graph.eps Using http://www.compileonline.com compiler
context_page_description: The Two-Rays Ground Reflected Model is a radio propagation model which predicts the path losses between a transmitting antenna and a receiving antenna when they are in LOS. Generally, the two antenna each have different height. The received signal having two components, the LOS component and the multipath component formed predominantly by a single ground reflected wave.
context_section_description: When the distance  between antennas is less than the transmitting antenna height, two waves are added constructively to yield bigger power. As distance increases, these waves add up constructively and destructively, giving regions of up-fade and down-fade. As the distance increases beyond the critical distance  or first Fresnel zone, the power drops proportionally to an inverse of fourth power of . An approximation to critical distance may be obtained by setting Δφ to π as the critical distance to a local maximum.
caption: Power vs distance plot
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