Z3D153 Vol 3 Unit 1
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Which are the two types of communications satellites?
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Delay and Passive
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Active and Passive
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Delay and Real-Time
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Active and Real-Time
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Z3D153 Vol 3 Unit 1 explores key aspects of satellite communications, focusing on the different segments, functions, and types of satellites. It assesses understanding of satellite technology, orbits, and communication methods, essential for learners in telecommunications.
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- 2.
Astronomical time is based on?
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Atomic clock oscillations.
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Apparent constellation movement.
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The moon's rotation about the earth.
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The apparent motion of the sun in the sky.
Correct Answer
A. 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 due to the rotation of the Earth on its axis. Astronomers use this motion to measure time, with the sun reaching its highest point in the sky at noon, marking the midpoint of the day. This method of timekeeping is different from atomic clock oscillations, which are used for precise and standardized time measurements.Rate this question:
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- 3.
Coordinated universal time (UTC) is based on what kind of clock system?
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12-hour.
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24-hour.
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Astronomical.
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Amplitude modulation and pulse modulation.
Correct Answer
A. 24-hour.Explanation
Coordinated Universal Time (UTC) is based on a 24-hour clock system. This means that the day is divided into 24 equal parts, with each part representing one hour. This system is used to standardize timekeeping across different time zones and ensure that everyone is using the same reference point for time. UTC is widely used in various fields such as aviation, telecommunications, and computer systems to ensure accurate and synchronized timekeeping worldwide.Rate this question:
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- 4.
Telecommunications service orders are issued by the?
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Department of Defense (DOD).
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User's technical control facility.
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National Communications System (NCS)
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Defense Information Systems Agency (DISA).
Correct Answer
A. Defense Information Systems Agency (DISA).Explanation
Telecommunications service orders are issued by the Defense Information Systems Agency (DISA). DISA is responsible for providing and managing telecommunications and information technology support to the Department of Defense (DOD). They oversee the planning, procurement, and implementation of telecommunications services for the DOD, including issuing service orders to ensure the smooth operation of communication systems. The other options, such as the DOD, user's technical control facility, and National Communications System, are not directly responsible for issuing telecommunications service orders.Rate this question:
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- 5.
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?
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Atomic time.
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Mean solar time.
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Astronomical time.
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Coordinated universal time.
Correct Answer
A. Coordinated universal time.Explanation
Coordinated Universal Time (UTC) is a time scale that provides a universally agreed standard time with the accuracy of atomic time. It is based on International Atomic Time (TAI) but also takes into account the earth's motion about the sun, ensuring synchronous operation. UTC is widely used in various fields such as aviation, telecommunications, and computing, as it provides a reliable and stable time reference that can be depended on globally. Mean solar time and astronomical time do not have the same level of accuracy and synchronization with atomic time as UTC.Rate this question:
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- 6.
The operation of the atomic clock is based on the phenomenon that?
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Crystals resonate when an electric charge is applied.
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Atoms release energy at a particular resonant frequency.
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Atoms are sensitive to temperature and directional effects.
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When atoms are split they produce predictable nuclear reactions.
Correct Answer
A. Atoms release energy at a particular resonant frequency.Explanation
The correct answer is that atoms release energy at a particular resonant frequency. Atomic clocks work by measuring the vibrations of atoms. When atoms are excited, they release energy in the form of electromagnetic radiation. This energy is emitted at a specific frequency, which is unique to each type of atom. By measuring these resonant frequencies, atomic clocks can accurately keep time.Rate this question:
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- 7.
A number of organizations can maintain accurate time-of-day clocks by referencing astandard time interval of one
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Second.
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Minute.
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Hour.
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Day.
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 a universally recognized unit of time measurement and is the smallest interval of time commonly used. By synchronizing their clocks to this standard, organizations can ensure that their timekeeping is precise and consistent.Rate this question:
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- 8.
Which of the following is not one of the three distinct elements that work together to make satellite communication (SATCOM) possible?
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Space Segment
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Control Segment
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Payload Segment
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Terminal Segment
Correct Answer
A. Payload SegmentExplanation
The payload segment is not one of the three distinct elements that work together to make satellite communication possible. The three elements are the space segment, control segment, and terminal segment. The space segment includes the satellite itself and the transponders that receive and transmit signals. The control segment consists of the ground-based control stations that monitor and control the satellite's operations. The terminal segment includes the equipment used by users to communicate with the satellite. The payload segment refers to the part of the satellite that carries the actual payload, such as data, video, or voice signals.Rate this question:
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- 9.
Which term describes the longest distance across an elliptical orbit?
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Minor Axis
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Major Axis
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Apogee
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Perigee
Correct Answer
A. Major AxisExplanation
The major axis is the correct answer because it represents the longest distance across an elliptical orbit. In an ellipse, the major axis is the line that passes through the center of the ellipse and is the longest distance from one end of the ellipse to the other. The minor axis, on the other hand, represents the shortest distance across the ellipse. Apogee and perigee, on the other hand, refer to the points in an orbit where an object is farthest and closest to the celestial body it is orbiting, respectively.Rate this question:
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- 10.
Which of the following satellite look angle methods is provided by (satellite communication SATCOM planners?
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Programed ground terminal
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Satellite access authorization
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Computer based application
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Satellite slide rule
Correct Answer
A. Satellite access authorizationExplanation
Satellite access authorization is a method provided by satellite communication SATCOM planners. This method involves obtaining authorization to access and use satellite communication services. It ensures that only authorized users can utilize the satellite resources, preventing unauthorized access and ensuring efficient and secure communication.Rate this question:
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- 11.
Which satellite access technique is being used when all channels are pooled and used by any station according to its instantaneous traffic load?
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Code division multiple access (CDMA).
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Time division multiple access (TDMA)
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Demand assigned multiple access (DAMA).
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Frequency division multiple access (FDMA).
Correct Answer
A. Demand assigned multiple access (DAMA).Explanation
In demand assigned multiple access (DAMA), all channels are pooled and can be used by any station based on its instantaneous traffic load. This means that the channels are dynamically assigned to stations as needed, allowing for efficient utilization of the available resources. CDMA, TDMA, and FDMA do not involve dynamic assignment of channels and do not allow for flexible sharing of resources based on traffic load.Rate this question:
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- 12.
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?
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Joint Staff.
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Combatant commander (COCOM).
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Consolidated Space Operations Center (CSOC).
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Defense Information Systems Agency Operations Control Complex (DOCC).
Correct Answer
A. Joint Staff.Explanation
When conflicts arise regarding DSCS GMF satellite resources that cannot be resolved by DISA and RSSC, they are ultimately resolved by the Joint Staff. The Joint Staff is responsible for assisting the Chairman of the Joint Chiefs of Staff in carrying out their responsibilities, which include providing military advice to the President and Secretary of Defense. As such, they have the authority and expertise to address and resolve conflicts related to defense satellite communications systems.Rate this question:
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- 13.
What two factors cause a quartz oscillator's resonant frequency to drift?
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Humidity and aging.
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Temperature and aging.
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Humidity and operating frequency.
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Temperature and operating frequency.
Correct Answer
A. Temperature and aging.Explanation
A quartz oscillator's resonant frequency can drift due to two factors: temperature and aging. Temperature changes can cause the crystal inside the oscillator to expand or contract, affecting its resonant frequency. Aging refers to the gradual degradation of the crystal's properties 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 the quartz oscillator's resonant frequency.Rate this question:
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- 14.
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
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Median.
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Latitude.
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Parallel.
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Meridian.
Correct Answer
A. Meridian.Explanation
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 meridian. The meridian is an imaginary line that runs from the North Pole to the South Pole and passes through the Greenwich Observatory in London, England. Time zones are based on the distance from this meridian, with each time zone representing a 15-degree difference in longitude. Therefore, by knowing the longitude of your location and the longitude of the meridian, you can calculate the time difference between UTC and your local time.Rate this question:
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- 15.
The agency responsible for coordinated universal time (UTC) is the
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United States Naval Observatory (USNO).
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International Bureau of Weights and Measures (BIPM).
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Precision Measurement Equipment Laboratory (PMEL).
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National Institute of Standards and Technology (NIST).
Correct Answer
A. 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 international organization that ensures the accuracy and consistency of measurements and standards worldwide. They work closely with various national metrology institutes, including the United States Naval Observatory (USNO) and the National Institute of Standards and Technology (NIST), to maintain and disseminate UTC. However, BIPM holds the primary responsibility for coordinating and maintaining the international standard for timekeeping.Rate this question:
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- 16.
Which of the following is not a function of the (satellite communication) SATCOM control segment?
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Spacecraft Control
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Network Control
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Payload Control
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Ground Control
Correct Answer
A. Ground ControlExplanation
The SATCOM control segment consists of various functions that are responsible for managing and controlling satellite communication. Spacecraft Control involves monitoring and controlling the spacecraft's operations and health. Network Control is responsible for managing the network infrastructure and ensuring connectivity. Payload Control manages the payload operations and configurations. Ground Control, on the other hand, is not a function of the SATCOM control segment. It refers to the control station on the ground that communicates with the satellite and manages overall operations, including monitoring and controlling the spacecraft's orbit, telemetry, tracking, and commanding.Rate this question:
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- 17.
What is the inclination angle of a polar orbit?
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0
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45
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90
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180
Correct Answer
A. 90Explanation
The inclination angle of a polar orbit is 90 degrees. A polar orbit is a type of orbit that passes over or near the Earth's North and South poles, allowing the satellite to cover the entire globe. In a polar orbit, the satellite's path is perpendicular to the Earth's equator, resulting in an inclination angle of 90 degrees. This allows the satellite to provide global coverage and is commonly used for Earth observation and mapping satellites.Rate this question:
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- 18.
One of the functions of the telecommunication certification office is to?
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Assign a circuit number to the telecommunications service request.
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Maintain case files on all major command (MAJCOM) circuits.
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Ensure the user agency is prepared to pay for the service
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Review the circuit priority against mission needs.
Correct Answer
A. Ensure the user agency is prepared to pay for the serviceExplanation
The function of the telecommunication certification office is to ensure that the user agency is prepared to pay for the service. This means that before providing the telecommunications service, the office verifies that the user agency has the necessary funds or resources to cover the cost. This helps to ensure that the service can be provided without any financial issues or delays.Rate this question:
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- 19.
Which satellite reflects signals transmitted toward it?
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Delay
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Active
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Passive
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Real-Time
Correct Answer
A. PassiveExplanation
Passive satellites reflect signals transmitted toward them. Unlike active satellites, which generate their own signals, passive satellites rely on receiving and reflecting signals from other sources. They do not actively transmit or amplify signals. Instead, they serve as a mirror, bouncing back the signals they receive. This makes passive satellites useful for tasks such as communication, weather monitoring, and navigation, where they can receive signals from ground-based stations and reflect them to specific locations on Earth.Rate this question:
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Current Version
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Mar 22, 2023Quiz Edited by
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Jul 30, 2017Quiz Created by
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