

Satellite Propagation Time Problem
Given the geostationary satellite diagram in Figure 2, calculate the maximum and minimum range in kilometers from an Earth
Station to a satellite in geosynchronous orbit. What is the roundtrip data signal propagation time for both maximum and
minimum ranges calculated?
Solution:
a) Calculated geosynchronous satellite ranges:
θ_{max} = cos^{1}(r_{e} / r_{s})
θ_{max} = cos^{1}(6370km / 42,242km) = 81.33 deg
And:
r_{min} = r_{s}  r_{e} = 35,872km
r_{max} = r_{s} sin (θ_{max}) = 41,759km
b) Round trip data transmission signal propagation time:
T_{min} = 2 (r_{min}) / c = 2 (35,872km) / 3E5km/s = 0.239s
T_{max} = 2 (r_{max}) / c = 2 (41,759km) / 3E5km/s = 0.278s
Satellite key words: geosynchronous orbit, RF signal, GEO, data transmission, transceiver, electromagnetic signal
propagation time, orbital parameters, range, kilometers, earth station, ES, attenuation, atmospheric.
