21
3-19. Why do satellite earth terminals require
highly sensitive receivers?
1. To overcome the down-link power
losses
2. To permit extraction of the desired
communications information from the
received signal
3. Both 1 and 2 above
4. Because of the signal scatter effect of
the antennas
3-20. Which of the following functions is
performed by the exciter stage of an earth
terminal transmitter?
1. Modulation of the IF carrier
2. Translation of the IF signal to the up-
link frequency
3. Amplification of the IF signal to the
level required by the receiver
4. Conversion of the down-link
frequency to an IF
3-21. Telemetery equipment used in satellite
communications systems performs which
of the following functions?
1. They monitor the operating
conditions within the satellite
2. They provide local control for
satellite operations
3. They furnish high-capacity wide-band
tty trunks
4. They measure ambient weather
conditions
3-22. A typical shipboard receive-only satellite
system uses which of the following types
of modulation?
1. Pulsed or amplitude
2. Pulsed or frequency
3. Amplitude or phase-shift-key
4. Frequency or phase-shift-key
3-23. Locating a near-synchronous satellite is
rather simple for which of the following
reasons?
1. It is stationary
2. It is moving north to south
3. It has a slow relative motion
4. It has a fast relative motion
3-24. What is the name of the table that
provides coordinates of a satellite at
specific times?
1. Bearing location
2. Longitudinal
3. Propagation
4. Ephemeris
3-25. To establish radio contact with a satellite,
an earth terminal must know which of the
following satellite data?
1. Attitude
2. Elevation
3. Operating speed
4. Angle of inclination
3-26. Satellite down-link frequency variations
occur most often from satellites in which
of the following orbits?
1. Low altitude elliptical
2. Medium altitude circular
3. High altitude synchronous
4. Superhigh altitude near-synchronous
3-27. Of the following terms, which one
describes the period of time required for
one earth terminal to yield control of a
satellite to another?
1. Slewing
2. Hand over
3. Control shift
4. Terminal continuity
