JPL's Wireless Communication Reference Website 

Chapter: Wireless Channels 
Section: Path Loss, Plane Earth Loss 


Two-Ray Model

 This model takes into account a line-of-sight and a ground reflection. It is a good approximation for propagation over a smooth well-reflecting terrain, as modeled by the plane-earth model, with

.

Matlab code

lambda = 0.3; 
ht100=100;
ht30=30;
ht2=2;
hr=2;

axis=[];
p100=[];
p30=[];
p2=[];
pfsl=[];


for i=1000:5000
 d=10^(i/1000);
 axis =[axis d]; 
 fspower  = (lambda/(4*3.1415*d))^2 ;
 power100 = fspower * 4 *(sin(2*3.1415*hr*ht100/(lambda*d)))^2;
 power30  = fspower* 4 *(sin(2*3.1415*hr*ht30/(lambda*d)))^2;
 power2   = fspower * 4 *(sin(2*3.1415*hr*ht2/(lambda*d)))^2;

 p100 =[p100, 10*log10(power100)];
 p30 =[p30, 10*log10(power30)];
 p2 =[p2, 10*log10(power2)];
 pfsl=[pfsl, 10*log10(fspower)];
end

text('FontSize',18)

semilogx(axis,p100, 'g-',axis,p30, 'b-',axis,p2, 'r-',axis,pfsl,'y-')
 
 
xlabel('distance in m');
ylabel('pathloss');
text(1000,-66,'blue  : hr=30m');
text(1000,-74,'red   : hr=2m');
text(1000,-58,'red   : hr=100m');
text(1000,-50,'yellow: free space');

text(50,-180,'lambda = 0.30 m');
text(50,-190,'hr = 2 m');

  

JPL's Wireless Communication Reference Website © Jean-Paul M.G. Linnartz, 1999.