the fraction of transmitted power that returns to appear
at the terminals of a unity gainreceiving antenna is
Example. Let us compute the pathlossfraction at
432 MHz. Since the Moon'sdiameter is approximately
d = 3475 km and themean distance from the Earth to
the Moon is R = 382,942 km,the pathloss fraction is
F = 7.078 x E(-27),
an unwieldy number. We should go over to decibels.