Page 120 - Satellite Communications, Fourth Edition

100 Chapter Three

3.12. Referring to Prob. 3.11, verify that the geostationary arc required for
CONUS plus Hawaii is 85° to 136° W and for CONUS plus Alaska is 115° to
136°W.
3.13. By taking the Mississippi River as the dividing line between east and
west, verify that the western region of the United States would be covered by
satellites in the geostationary arc from 136° to 163°W and the eastern region
by 25° to 55°W. Assume a 5° angle of elevation.
3.14. (a) An earth station is located at latitude 35°N. Assuming a polar mount
antenna is used, calculate the angle of tilt. (b) Would the result apply to polar
mounts used at the earth stations specified in Probs. 3.6 and 3.8?

3.15. Repeat Prob. 3.14 (a) for an earth station located at latitude 12°S.
Would the result apply to a polar mount used at the earth station specified in
Prob. 3.7?
3.16. Repeat Prob. 3.14 (a) for an earth station located at latitude 30°S.
Would the result apply to a polar mount used at the earth station specified in
Prob. 3.9?

3.17. Calculate the angle of tilt required for a polar mount antenna used at your
home location.

3.18. The borders of a certain country can be roughly represented by a
triangle with coordinates 39°E, 33.5°N; 43.5°E, 37.5°N; 48.5°E, 30°N. If a
geostationary satellite has to be visible from any point in the country,
determine the limits of visibility (i.e., the limiting longitudinal positions for
a satellite on the geostationary arc). Assume a minimum angle of elevation for
the earth station antenna of 5°, and show which geographic location fixes
which limit.

3.19. Explain what is meant by the earth eclipse of an earth-orbiting satellite.
Why is it preferable to operate with a satellite positioned west, rather than east,
of earth station longitude?
3.20. Explain briefly what is meant by sun transit outage.

3.21. Using the data given in Fig. 3.7, calculate the longitude for INTELSAT
904.
3.22. Calculate the semimajor axis for INTELSAT 901.

3.23. Calculate the apogee and perigee heights for INTELSAT 906.

3.24. Calculate the rate of regression of the nodes and the rate of rotation of
the line of apsides for INTELSAT 907.