M.Sc. (Semester IV) (CBCS) Examination Mar/Apr-2018
Electronics Science
SATELLITE COMMUNICATION
Time: 2½ Hours
Max. Marks: 70
Instructions: Questions 1 and 2 are compulsory. Answer any three questions from Q.3 to Q.7. All questions carry equal marks. Use of nonprogrammable calculator is allowed.
Q.1

Select the most correct alternative:
14
Orbital velocity of Iridiam satellite system is if the orbital height of the system is 780km.
3.0747 km/s
4.8954 km/s
1.1272 km/s
7.4624 km/s
angle is an angle that the orbital plane makes with the equatorial plane.
Elevation
Azimuth
Inclination
Argument of perigee
At the point of Greenwich meridian,
Longitude is 0°
Longitude is 180°
Latitude is 360°
Latitude is 90°
Which of the following is NGSO orbit?
Equatorial orbit
Elliptical orbits
Sun synchronous orbit
All of the above
A satellite can make better use of its solar cell area.
Spinner
3-axis stabilized
LEO
GEO
A dish antenna is a type of antenna.
Patch
Reflector
Array
Wire
Outage time of Ka-band is per year.
0.01%
0.1%
0.1-0.5%
0.5%
Change in the orbital plane is called
Doppler shift
Retrograde
Transit outage
Precession
The orbital period of GPS satellite is equal to
One sidereal day
Half of a sidereal day
5hr 55min 48.4s
1hr 40 min 27s
10) Eccentricity of the molniya orbit is
1
0
Greater than 1
0.74
Page 2 of 2
SLR-UH-315
11) The diameter of a DTH antenna is
0.45-0.9m
1m
5m
5-8 m
12) orbit satellite maintains a constant aspects angle with the direction of sun.
LEO
MEO
GEO
Sun synchronous
13) An amplifier has a quoted noise figure of 2.5 dB. What is its equivalent noise temperature?
290K
120k
226k
279K
14) constellation is specially designed for business links.
GPS
VSAT
Iridium
Teledesic
Q.2
Answer the following:
Explain TTC M system.
05
Explain uplink design.
05
What is reliability?
04
Q.3
Explain the look angle determination. Derive elevation and azimuthal angles.
10
What are the selection factors of launch vehicle?
04
Q.4
Explain the communication sub-system of a satellite. Give a brief account of transponder with a neat block diagram.
10
Comment on three prototype models of space qualifications.
04
Q.5
Give the brief explanation of system noise temperature.
10
Discuss the satellite systems using small earth stations.
04
Q.6
What is DBS-TV? Explain digital DBS-TV.
08
Explain coverage and frequency considerations of NGSO satellite.
06
Q.7
Explain the following segments of a GPS system.
Space
User
Control
10
What are the advantages of satellite communication?
04