Question

Plot a graph describing the LOS distance in miles for transmitting antennas with heights from 0 ft up to 140155 ft. Assume that the receiving antenna is 5 ft above the ground. Discuss the results in couple of line and if user wanted to cover LOS 35 mile then what transmitting antenna height he should use? in matlab

Answer 1

Maximum distance between antennas for LOS propogation :

where :

h1 = height of antenna one (m)

h2 = height of antenna two (m)

k = adjustment factor to account for refraction, rule of thumb K = 4/3

The distance we get is km

Our conversion is from feet to miles. Accordingly we add conversion factors.

Matlab code for plotting :

h1 = 0 : 1 : 42719; % height from 0 foot to 140155 feet
h2 = 1.524 ; % 5 feet to metres
n = 4.122 * 0.62137; % overall conversion to miles
y = h1.^0.5 + h2.^0.5;
plot (h1 , n.*y); % final plot - on x axis : height of antenna one , on y axis : LOS in miles

According to above for 508.53 feet antenna, LOS will be 35 miles.

The graph is a right facing parabola.