An inter satellite link is established between two satellite

An inter satellite link is established between two satellites. One satellite located at 325.5degreeE is transmitting with an EIRP of 20 dBW. The receiving satellite is at 359 degree E. Find the distance S between them, in km, and the illumination W in dBW/m^2.

Solution

for geostationary satellites illumination is given by,

W = EIRP - 162 dBW/m^2

W = 20 -162 = -142 dBW/m^2

locations of the satellites are 325.5E and 359E

distance = S = R(2 - 2cos(359-325.5))^0.5 = 0.42R

R is the distance of satellite from earth centre.