Satellite Orbits
What is the term for a satellite orbit that maintains a fixed position relative to a point on Earth?
Geostationary Orbit
Question: Which power source is most commonly used for satellites due to its availability in space?
Solar Energy
Name the tracking technique that involves an antenna beam rapidly switching between two positions around the axis.
Lobe Switching
In an Earth station, what component amplifies weak signals received by the antenna?
Low Noise Amplifier
What is the role of the cladding layer in an optical fiber?
The cladding, with a slightly lower refractive index than the core, supports the waveguide structure and reduces radiation loss.
What type of orbit is inclined at 90 degrees to the equatorial plane, allowing the satellite to pass over the poles?
Polar Orbit
How do satellites continue to function during periods when they are eclipsed from the sun?
By using rechargeable batteries that store energy from solar panels
What is the tracking method that scans the antenna beam in a circular path to monitor satellite location?
Conical Scan
What Earth station system is responsible for converting baseband signals to higher frequencies for transmission?
Up-Converter
Which index of refraction gradually decreases away from the center of the core?
Graded Index
According to Kepler's laws, what happens to a satellite's speed as it moves closer to Earth in an elliptical orbit?
The satellite’s speed increases as it approaches Earth
Name two types of rechargeable batteries commonly used in geostationary satellites for power storage.
Nickel-Cadmium (NiCd) and Lithium-Ion
What does the telemetry system transmit back to the Earth station as part of satellite tracking and health monitoring?
Data on satellite health, including power levels, temperature, and component status
What measure of an Earth station's performance is derived from the gain of the receiving antenna and the system noise temperature?
G/T ratio
What term describes the phenomenon where a pulse broadens as a result of wavelength-dependent speed variations in a fiber?
Dispersion
What is the significance of the Right Ascension of the Ascending Node (RAAN) in determining the orbital path of a satellite?
It defines the angle from a reference direction (usually the vernal equinox) to the point where the satellite crosses the equatorial plane from South to North, influencing the satellite's ground trackategory
In a satellite power system, what is the function of the Power Conditioning Unit (PCU), and how does it contribute to the overall power management strategy?
The PCU regulates the voltage and current from solar panels and batteries, ensuring that the satellite’s systems receive stable and appropriate power levels while also managing battery charging and discharging cycles .
What is the purpose of the Kalman filter in satellite tracking, and how does it improve accuracy in estimating a satellite's position?
The Kalman filter uses a series of measurements observed over time to estimate the unknown variables of the satellite’s position and velocity, effectively reducing noise and increasing tracking accuracy by predicting future states based on previous measurements .
In the context of Earth station design, how does intermodulation distortion (IMD) affect the performance of multi-carrier systems, and what strategies can be implemented to mitigate its effects?
IMD occurs when multiple carriers interact within non-linear components, creating additional unwanted frequencies that can interfere with signals. Strategies to mitigate IMD include using linear amplifiers, proper signal filtering, and designing appropriate spacing between carriers
How does the Group Velocity Dispersion (GVD) affect pulse broadening in optical fibers?
Causes different frequency by broadening the pulse
If an optical fiber has an attenuation of 0.5 dB/km and an initial input power of 20 mW, find the length of fiber required for the output power to drop to 5 mW.
12.04 km
Calculate the Brewster angle for light moving from air (with n1=1.0) into glass (with n2=1.5n).
Brewster angle=56.31 degree
A satellite is in a highly elliptical orbit around the Earth with a semi-major axis of 15,000 kmand an eccentricity of 0.20.Calculate the apogee (ra) and perigee (rp) distances of the satellite from the center of the Earth.
An optical signal with an input power of Pin=10 mW travels through a 5-km fiber and reaches an output power Pout=2 mW. Calculate the total attenuation and the attenuation per kilometer.
The total attenuation over 5 km is approximately 7 dB, and the attenuation per kilometer is 1.4 dB/km.
Calculate the critical angle for total internal reflection if the core refractive index is 1.52 and the cladding refractive index is 1.47.
76.1