3D153 Volume 3 UREs

The signal originating from the satellite that we use to acquire and track the satellite is the beacon.

UTC (Coordinated Universal Time) is based on a 24-hour clock system. This means that the time is divided into 24 equal parts, with each part representing an hour. The use of a 24-hour clock allows for a standardized and globally recognized system of timekeeping, which is essential for coordinating activities and events across different time zones. It eliminates any confusion that may arise from using a 12-hour clock system, which requires the use of AM and PM to distinguish between morning and afternoon/evening hours. Astronomical and modulation methods are not relevant to the basis of UTC.

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 then amplify and retransmit them back to the designated receivers. They actively participate in the communication process. On the other hand, passive satellites reflect or redirect signals without any amplification or modification. They simply act as a medium to bounce signals from one location to another. Therefore, active and passive are the two types of communications satellites.

Passive satellites are designed to reflect signals transmitted towards them. Unlike active satellites, which generate their own signals, passive satellites rely on reflecting the signals they receive. This makes passive satellites ideal for applications such as communication, weather monitoring, and navigation, where the satellite acts as a relay station for signals transmitted from the ground.

A quartz oscillator's resonant frequency can drift due to changes in temperature and aging. Temperature variations can cause the quartz crystal to expand or contract, affecting its resonant frequency. Aging refers to the gradual degradation of the quartz crystal over time, which can also lead to changes in its resonant frequency.

The inclination angle of a polar orbit is 90° because a polar orbit is one that passes over or near the Earth's poles. In this type of orbit, the satellite travels from the North Pole to the South Pole and vice versa, covering the entire surface of the Earth. The inclination angle determines the angle at which the orbit is tilted relative to the equator, and for a polar orbit, this angle is 90°.

The correct answer is Defense Information Systems Agency (DISA). DISA is responsible for issuing telecommunications service orders. The Department of Defense (DOD) is a broader organization that oversees various aspects of national defense, but it is not specifically responsible for issuing telecommunications service orders. The user's technical control facility is responsible for managing and maintaining the user's telecommunications systems, but it does not issue service orders. The National Communications System (NCS) is a former organization that was responsible for coordinating national security and emergency preparedness telecommunications, but it does not issue service orders.

The demodulator is responsible for extracting the original information signal from the modulated carrier signal. In this context, "stripping away the intelligence" refers to the process of removing the modulating signal from the intermediate frequency. The demodulator accomplishes this by reversing the modulation process, allowing the original signal to be recovered and further processed. Therefore, the demodulator is the module that performs this task, making it the correct answer.

The Inmarsat headquarters is located in London, England. This can be inferred from the given options where each location is mentioned along with its corresponding country. Among these options, London, England is the correct answer as it matches the location of the Inmarsat headquarters.

Satellite access authorization is a method provided by satellite communication SATCOM planners. This method involves granting permission to access and use the satellite for communication purposes. It ensures that only authorized users can connect to the satellite and utilize its services. The other options mentioned, such as programmed ground terminal, computer-based application, and satellite slide rule, do not specifically pertain to the process of authorizing satellite access.

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. This algorithm allows the receiver to detect and correct errors in the received message by comparing the multiple copies. This ensures that the message is accurately received even if there are errors introduced during transmission. 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.

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 that can be precisely measured and synchronized across different clocks and systems. By using a standard time interval of one second, organizations can ensure that their clocks are accurately synchronized, allowing for consistent and reliable timekeeping.

The highest priority mission of the Defense Support Program (DSP) is the North American warning. This mission involves detecting and warning of any potential threats to the North American continent, including missile launches or other attacks. It is crucial for the DSP to prioritize this mission in order to ensure the safety and defense of North America.

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. This means that channels are dynamically assigned to stations based on their demand, allowing for efficient utilization of resources. Unlike other access techniques such as CDMA, TDMA, and FDMA, which have fixed assignments, DAMA allows for flexibility and adaptability in allocating channels based on real-time traffic needs.

The major axis is the term that describes the longest distance across an elliptical orbit. This axis runs from one end of the ellipse to the other, passing through the center. The minor axis, on the other hand, is the shortest distance across the orbit. Apogee and perigee, on the other hand, refer to the points in an orbit where the distance between the orbiting object and the body it is orbiting is at its maximum (apogee) or minimum (perigee).

The MILSTAR antenna that provides high gain, selective coverage of any ground station visible on the earth's surface within its own footprint is the spot beam. This antenna is designed to focus its signal on a specific area or "spot" on the ground, allowing for targeted communication with ground stations within that area. This selective coverage helps to optimize the efficiency and effectiveness of military strategic and tactical relay communications.

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 Joint Staff. The Joint Staff is responsible for providing military advice and support to the Chairman of the Joint Chiefs of Staff and the combatant commanders. They oversee the overall coordination and integration of military operations and resources, making them the appropriate authority to resolve conflicts in this scenario.

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, allowing us to measure the passage of time. The movement of the sun is used as a reference for determining the length of a day and for establishing time zones. Atomic clock oscillations, apparent constellation movement, and the moon's rotation about the earth are not directly used to measure astronomical time.

Satellite communication (SATCOM) involves three distinct elements that work together: the space segment, control segment, and terminal segment. The space segment refers to the satellites in space that transmit and receive signals. The control segment consists of ground-based stations that manage and control the satellites. The terminal segment includes the devices used by users to send and receive signals from the satellites. The payload segment, on the other hand, is not one of the three elements. It refers to the part of the satellite that carries the actual data or information being transmitted, such as television signals or internet data.

Coordinated Universal Time (UTC) is a time scale that provides a universally agreed standard time scale 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 reference. UTC is widely used in various fields, including aviation, telecommunications, and global navigation systems, to ensure consistent and synchronized timekeeping worldwide.

The operation of an atomic clock is based on the phenomenon that atoms release energy at a particular resonant frequency. This means that when atoms are excited, they emit energy in the form of electromagnetic radiation at a specific frequency. By measuring this frequency, the atomic clock can accurately keep time. The resonant frequency of atoms is highly stable and consistent, making it an ideal basis for timekeeping.

The correct answer is "meridian." To determine the number of hours UTC differs from your local time, you need to determine the number of time zones between your location and the location of the zero meridian. The zero meridian, also known as the Prime Meridian, is the line of longitude that passes through Greenwich, London, and serves as the reference point for measuring time zones around the world. By calculating the time difference between your location and the zero meridian, you can determine the number of hours UTC differs from your local time.

Multiplexing refers to the process of combining multiple information channels onto a common transmission medium. This allows for the efficient use of the transmission medium by transmitting multiple signals simultaneously. By multiplexing, different signals can be transmitted over the same medium without interfering with each other, thus increasing the overall capacity and efficiency of the transmission system.

The up converter is the SATCOM system module that is used to produce the final transmit frequency. It converts the baseband signal to a higher frequency before transmission. This process involves mixing the baseband signal with a local oscillator signal to generate the desired transmit frequency. The up converter is an essential component in satellite communication systems as it enables the transmission of signals at the appropriate frequency for communication with the satellite.

The International Bureau of Weights and Measures (BIPM) is responsible for coordinating the universal time (UTC). They are an international organization that ensures the accuracy and consistency of measurements worldwide. The BIPM collaborates with various national laboratories, including the United States Naval Observatory (USNO), Precision Measurement Equipment Laboratory (PMEL), and National Institute of Standards and Technology (NIST), to maintain and distribute the UTC. However, the BIPM is the primary agency responsible for setting and maintaining the international standard for timekeeping.

Wavelength division multiplexing assigns each incoming optical signal a specific frequency of light. This means that different signals can be transmitted simultaneously through a single optical fiber by using different wavelengths of light to carry each signal.

XTAR is the correct answer because it is a satellite company that is specifically designed to interface with all current X-band terminals. This means that XTAR satellites are compatible with the X-band terminals used by various organizations and military forces for communication and data transmission purposes. In contrast, Inmarsat, INTELSAT, and EUTELSAT are satellite companies that may offer different types of services and may not be specifically focused on X-band terminals.

When the same frequency radiates simultaneously in two different planes, it is referred to as polarization diversity. Polarization refers to the orientation of the electric field vector in an electromagnetic wave. In this case, the wave is radiating in two different planes, indicating a diversity in polarization. This type of diversity is commonly used in wireless communication systems to mitigate the effects of signal fading and improve signal quality and reliability.

The satellite readout station equipment group consists of the equipment required to receive and process signals from a satellite. This includes the radio frequency set, which is used to receive the signals, the transmit/receiver set, which allows for two-way communication with the satellite, and the digital equipment set, which processes and analyzes the received data.

INMARSAT mobile satellite services (MSS) include Swift broadband, Fleet broadband (maritime), and Broadband Global Area Network (BGAN). However, Iridium is not included in INMARSAT MSS.

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 assigning a circuit number to the telecommunications service request, the office checks if the user agency has the necessary funds or resources to cover the cost of the service. This step is important to ensure that the agency can financially support the requested service and prevent any potential payment issues or delays in the future.

The SATCOM control segment is responsible for managing and controlling satellite communications. It includes functions such as spacecraft control, network control, and payload control. However, ground control is not a function of the SATCOM control segment. Ground control typically refers to the operations and management of ground-based equipment and facilities, which are separate from the control segment responsible for satellite operations.

The low noise amplifier is the first step of the receive signal path because it amplifies the weak incoming signal from the antenna while introducing minimal noise. This is crucial to ensure that the signal is strong enough to be processed further in the system without being corrupted by noise. The down converter, up converter, and demodulator are all subsequent steps in the receive signal path that process the amplified signal in different ways, but the low noise amplifier comes first to boost the signal's strength.

The Air Force Satellite Control Network (AFSCN) command and control nodes consist of the Environmental Satellite Operations Center at Schriever AFB, CO, and the National Oceanographic and Atmospheric Administration (NOAA) Satellite Operations Control Center at Suitland, MD. These two centers are responsible for the management and control of satellite operations, ensuring the functionality and effectiveness of the Air Force's satellite network.

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The correct answer is solid state. Solid state power amplifiers use semiconductor transistors designed for microwave and higher frequency RF operation. These transistors are capable of providing high power output and operate efficiently at high frequencies. Solid state power amplifiers are commonly used in applications such as radar systems, satellite communications, and wireless networks. They offer advantages such as compact size, lightweight, and high reliability compared to other types of power amplifiers like klystrons or traveling wave tube amplifiers.

The MARK IVB antennas can be located up to 1500 feet away from the processing area.

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Polarization diversity requires two antennas, two receivers, and two transmitters. This type of diversity is used to improve the quality and reliability of wireless communication by reducing the effects of multipath interference. By using antennas with different polarizations, the system can receive signals from multiple paths and combine them to create a stronger and more reliable signal. This technique is commonly used in wireless communication systems such as Wi-Fi and cellular networks.

Crosslinking refers to the ability of MILSTAR to establish direct communication links between satellites in space without relying on ground-based stations. This capability is different from previous MILSATCOM and commercial satellite communications systems, which typically require ground-based stations to relay signals between satellites. Crosslinking allows for faster and more secure communication between satellites, enhancing military strategic and tactical capabilities.

Iridium is the correct answer because it is the only commercial satellite communication system that can offer true pole-to-pole global coverage. Unlike other systems like INTELSAT, EUTELSAT, and INMARSAT which have limited coverage, Iridium's network consists of a constellation of satellites that are evenly distributed around the Earth, allowing for communication in even the most remote and polar regions.

The programmed track method does not require any input from a satellite. This method involves pre-programming a specific path or route for the tracking device to follow, without relying on satellite signals for guidance. It is a predetermined and fixed track that the device will follow autonomously, without the need for real-time satellite updates or communication.

Each UHF Follow-on satellite has a total of 39 ultrahigh frequencies (UHF) channels available.

Ku-band service for commercial satellite services is not available worldwide. It is primarily located over land masses and highly populated areas. This means that the service coverage is limited to specific regions where there is a higher demand for satellite communications, such as urban areas and densely populated regions. It is not available over ocean areas and sparsely populated areas.

The correct answer is 6. The Global Positioning System (GPS) consists of 6 orbital planes, with each plane containing multiple satellites. These satellites are evenly distributed in their respective planes to ensure global coverage and accurate positioning.

The correct answer is Time. Time division multiplexing (TDM) is a multiplexing technique where each low-speed channel is sampled in sequence, and the bits or characters are interleaved and transmitted at a high speed. This allows multiple channels to share the same transmission medium by taking turns using it for short periods of time.

Planning is the correct answer because in the MILSTAR mission, the allocation of communication resources is a crucial aspect of ensuring effective and efficient communication. Planning involves determining the specific communication needs, identifying available resources, and allocating them accordingly. This process helps in optimizing the use of communication resources and ensuring that they are allocated to the right units or individuals as required for the mission's success.

The MILSTAR satellite sends downlink communications transmissions at ultrahigh frequency (UHF) and super-high frequency (SHF). This means that it uses both UHF and SHF to transmit its communications.

Handheld satellite phone communications are not normally provided through commercial wideband services. Wideband services typically refer to high-speed internet connectivity, video teleconferencing, and very small aperture terminal networks. Handheld satellite phones operate on a different technology and network infrastructure, allowing users to communicate via satellite signals in remote or disaster-stricken areas where traditional communication networks may be unavailable.

The correct answer is Ultrahigh frequency (UHF) follow-on. The UHF follow-on satellite system provides Global Broadcast Services (GBS). This system is designed to provide worldwide coverage for broadcasting data, including video, audio, and other multimedia content. It operates in the UHF frequency range, which allows for efficient and reliable communication over long distances. The UHF follow-on satellites are used by various organizations, including the military, to broadcast information globally.