1.
Which of the following is not one of the three distinct elements that work together to make satellite communication (SATCOM) possible?
Correct Answer
C. Payload segment.
Explanation
Satellite communication (SATCOM) involves three distinct elements that work together: the space segment, control segment, and terminal segment. The space segment consists of the satellites themselves, which transmit and receive signals. The control segment includes the ground-based stations that monitor and control the satellites. The terminal segment refers to the devices used by users to send and receive signals to and from the satellites. The payload segment, on the other hand, is not one of these elements. It refers to the actual data or information being transmitted through the satellite communication system.
2.
Which of the following is not a function of the (satellite communication) SATCOM control segment?
Correct Answer
D. Ground control.
Explanation
The SATCOM control segment consists of various components responsible for managing and controlling satellite communication. Spacecraft control involves monitoring and controlling the satellite's functions and movements in space. Network control handles the management of the communication network and routing of data. Payload control manages the satellite's payload, which includes the equipment used for transmitting and receiving signals. Ground control refers to the control center on Earth that monitors and manages the overall SATCOM system. Among these options, ground control is not a function of the SATCOM control segment as it refers to the physical location rather than a specific control task.
3.
Which term describes the longest distance across an elliptical orbit?
Correct Answer
B. Major axis.
Explanation
The major axis of an elliptical orbit refers to the longest distance across the ellipse. In an elliptical orbit, the shape resembles an elongated oval, and the major axis is the line that extends from one end of the ellipse to the other, passing through the center. This axis determines the maximum distance between the orbiting object and the focus point of the ellipse. Therefore, the major axis is the correct term to describe the longest distance across an elliptical orbit.
4.
What is the inclination angle of a polar orbit?
Correct Answer
C. 90°.
Explanation
The inclination angle of a polar orbit is 90°. A polar orbit is a type of orbit where a satellite passes over or near the Earth's poles on each orbit. In this type of orbit, the satellite's path is perpendicular to the equator, resulting in an inclination angle of 90°. This allows the satellite to cover the entire Earth's surface over time, making it useful for applications such as Earth observation and weather monitoring.
5.
Which are the two types of communications satellites?
Correct Answer
B. Active and passive.
Explanation
The correct answer is active and passive. Communications satellites can be categorized into two types based on their functionality. Active satellites are equipped with transponders that receive signals from Earth and amplify them before transmitting them back to the ground. These satellites actively participate in the communication process. On the other hand, passive satellites reflect signals back to Earth without any amplification or alteration. They simply bounce the signals off their surface. Therefore, the two types of communications satellites are active and passive.
6.
Which satellite reflects signals transmitted toward it?
Correct Answer
C. Passive.
Explanation
Passive satellites are designed to reflect signals transmitted towards them. Unlike active satellites, which generate their own signals, passive satellites simply reflect and redirect signals back to Earth. They are commonly used for communication purposes, such as relaying television or radio signals. Therefore, the correct answer is "Passive."
7.
Which of the following satellite look angle methods is provided by (satellite communication SATCOM planners?
Correct Answer
B. Satellite access authorization.
8.
Which satellite access technique is being used when all channels are pooled and used by any station according to its instantaneous traffic load?
Correct Answer
C. Demand assigned multiple access (DAMA).
Explanation
Demand assigned multiple access (DAMA) is the satellite access technique being used when all channels are pooled and used by any station according to its instantaneous traffic load. In DAMA, channels are dynamically assigned to stations based on their demand or need, allowing efficient and flexible use of satellite resources. This technique ensures that each station gets access to the required number of channels based on its traffic load at any given time. CDMA, TDMA, and FDMA are not suitable in this case as they do not provide the same level of flexibility and adaptability in channel allocation as DAMA does.
9.
Conflicts regarding Defense Satellite Communications System (DSCS) ground mobile forces (GMF) satellite resources that cannot be settled by the Defense Information Systems Agency (DISA) and the regional satellite communications support center (RSSC) are resolved by the
Correct Answer
A. Joint Staff.
Explanation
When the Defense Information Systems Agency (DISA) and the regional satellite communications support center (RSSC) are unable to resolve conflicts regarding Defense Satellite Communications System (DSCS) ground mobile forces (GMF) satellite resources, the responsibility falls on the Joint Staff to resolve the issue. The Joint Staff is responsible for providing military advice to the combatant commanders and the Secretary of Defense, and they oversee the overall military operations and planning. Therefore, they have the authority to settle conflicts related to satellite resources in the Defense Satellite Communications System (DSCS) ground mobile forces (GMF).
10.
One of the functions of the telecommunication certification office is to
Correct Answer
C. Ensure the user agency is prepared to pay for the service.
Explanation
The telecommunication certification office ensures that the user agency is prepared to pay for the service. This means that before assigning a circuit number to the telecommunications service request, the office verifies that the user agency has made the necessary arrangements and is financially ready to cover the cost of the service. This step helps to ensure that the telecommunications service is not provided without proper payment arrangements in place.
11.
Telecommunications service orders are issued by the
Correct Answer
D. Defense Information Systems Agency (DISA).
Explanation
The correct answer is Defense Information Systems Agency (DISA). DISA is responsible for issuing telecommunications service orders. The Department of Defense (DOD) is a government agency that oversees the military, but it is not specifically responsible for issuing service orders. The user's technical control facility may play a role in managing and controlling telecommunications services, but it is not responsible for issuing the orders. The National Communications System (NCS) is a former agency that has been absorbed by DISA.
12.
Astronomical time is based on
Correct Answer
D. The apparent motion of the sun in the sky.
Explanation
Astronomical time is based on the apparent motion of the sun in the sky. This is because the sun's position in the sky changes throughout the day, and this change is used to measure time. The apparent motion of the sun is caused by the rotation of the Earth on its axis, resulting in the sun appearing to rise in the east and set in the west. This motion is consistent and predictable, making it a reliable basis for measuring time.
13.
What time scale gives us a universally agreed to standard time scale with the stability and accuracy of atomic time and synchronous operation with the earth’s motion about the sun we can depend on?
Correct Answer
D. Coordinated universal time.
Explanation
Coordinated Universal Time (UTC) is a time scale that provides a universally agreed-upon standard time with the stability and accuracy of atomic time. It also ensures synchronous operation with the Earth's motion about the sun, making it a reliable time scale. UTC is used worldwide as a reference for various applications, including international communication, global navigation systems, and scientific research.
14.
What two factors cause a quartz oscillator’s resonant frequency to drift?
Correct Answer
B. Temperature and aging.
Explanation
A quartz oscillator's resonant frequency can drift due to two factors: temperature and aging. Temperature changes can affect the stability of the quartz crystal, causing its resonant frequency to shift. Aging refers to the gradual degradation of the crystal over time, which can also lead to a drift in the resonant frequency. Humidity and operating frequency are not directly responsible for causing the drift in a quartz oscillator's resonant frequency.
15.
The operation of the atomic clock is based on the phenomenon that
Correct Answer
B. Atoms release energy at a particular resonant frequency.
Explanation
The correct answer is that atoms release energy at a particular resonant frequency. This is the basis for the operation of an atomic clock. Atomic clocks use the vibrations of atoms to measure time accurately. When atoms are excited, they release energy in the form of electromagnetic radiation at a specific frequency. By measuring these vibrations, the atomic clock can keep precise time.
16.
To determine the number of hours coordinated universal time (UTC) differs from your local time, you must determine the number of time zones between your location and the location of the zero
Correct Answer
D. Meridian.
Explanation
The question is asking for the correct term to determine the number of hours coordinated universal time (UTC) differs from your local time. The answer is "meridian." A meridian is a line of longitude that runs from the North Pole to the South Pole and is used as a reference point for determining time zones. By calculating the number of meridians between your location and the location of the zero meridian (which passes through Greenwich, London), you can determine the time difference between your local time and UTC.
17.
Coordinated universal time (UTC) is based on what kind of clock system?
Correct Answer
B. 24-hour.
Explanation
The correct answer is 24-hour. Coordinated Universal Time (UTC) is based on a 24-hour clock system, which is commonly used in many countries around the world. This system divides the day into 24 equal parts, with each hour representing a specific time. UTC is used as a standard time reference for various purposes, including international communication, aviation, and global time synchronization.
18.
A number of organizations can maintain accurate time-of-day clocks by referencing a standard time interval of one
Correct Answer
A. Second.
Explanation
Organizations can maintain accurate time-of-day clocks by referencing a standard time interval of one second. This is because a second is the most precise unit of time measurement commonly used. By synchronizing their clocks to a standard second, organizations can ensure that their timekeeping is accurate and consistent. This is important for various applications, such as coordinating schedules, conducting experiments, or ensuring the accuracy of financial transactions.
19.
The agency responsible for coordinated universal time (UTC) is the
Correct Answer
B. International Bureau of Weights and Measures (BIPM).
Explanation
The International Bureau of Weights and Measures (BIPM) is responsible for coordinating universal time (UTC). BIPM is an intergovernmental organization that ensures the worldwide uniformity of measurements and standards. It maintains the International Atomic Time (TAI) and coordinates it with UTC through the use of leap seconds. The United States Naval Observatory (USNO), Precision Measurement Equipment Laboratory (PMEL), and National Institute of Standards and Technology (NIST) are also involved in timekeeping and standards, but BIPM is the agency responsible for UTC coordination.
20.
What is multiplexing?
Correct Answer
C. Combining multiple information channels onto a common transmission medium.
Explanation
Multiplexing refers to the process of combining multiple information channels onto a common transmission medium. This allows for efficient use of the available bandwidth by transmitting multiple signals simultaneously. By multiplexing, different data streams can be sent over the same transmission path, which increases the capacity and utilization of the network. This technique is commonly used in telecommunications and computer networks to optimize the use of resources and improve overall efficiency.
21.
What specifically does wavelength division multiplexing assign each incoming optical signal?
Correct Answer
B. Frequency of light.
Explanation
Wavelength division multiplexing assigns each incoming optical signal a specific frequency of light. This technique allows multiple optical signals to be transmitted simultaneously over a single optical fiber by assigning each signal a different wavelength. By using different frequencies of light, the signals can be separated and transmitted without interfering with each other. This enables efficient and high-capacity communication over optical networks.
22.
Which multiplexing division technique samples each low speed channel in sequence to interleave bits or characters and then transmit them at high speed?
Correct Answer
D. Time.
Explanation
The correct answer is time. Time division multiplexing (TDM) is a multiplexing division technique that samples each low-speed channel in sequence, interleaves the bits or characters, and then transmits them at a high speed. TDM assigns a specific time slot to each channel, allowing multiple channels to share the same transmission medium. This technique is commonly used in telecommunications to optimize the utilization of bandwidth and efficiently transmit multiple signals over a single communication link.
23.
Which of the following relies on the transmitter to send multiple copies of the same message to the distant end using a predetermined algorithm?
Correct Answer
C. Forward error correction.
Explanation
Forward error correction is a technique that relies on the transmitter to send multiple copies of the same message to the distant end using a predetermined algorithm. It involves adding redundant information to the original message, which allows the receiver to detect and correct errors that may occur during transmission. This redundancy ensures that even if some bits are corrupted or lost, the original message can still be reconstructed accurately at the receiver's end. Controlled diphase, non-return to zero, and quadrature phase shift keying (QPSK) are modulation techniques and do not involve sending multiple copies of the same message for error correction.
24.
Which SATCOM system module is used to produce the final transmit frequency?
Correct Answer
A. Up converter.
Explanation
The up converter is the SATCOM system module that is used to produce the final transmit frequency. It takes the baseband signal from the modulator and converts it to a higher frequency that is suitable for transmission through the antenna. The up converter is responsible for translating the signal to the desired frequency band and ensuring that it is within the appropriate range for satellite communication. This module plays a crucial role in the overall transmission process of the SATCOM system.
25.
Which type of power amplifier uses semiconductor transistors designed for microwave and higher frequency RF operation?
Correct Answer
B. Solid state.
Explanation
Solid state power amplifiers use semiconductor transistors designed for microwave and higher frequency RF operation. This type of amplifier does not require any vacuum tubes or specialized components, making it more compact, efficient, and reliable compared to other types of power amplifiers. Solid state amplifiers are commonly used in various applications such as telecommunications, radar systems, and wireless communication devices.