SUB-ELEMENT P Flashcards
What is the orbiting altitude of the Iridium satellite communications system?
A. 22,184 miles.
B. 11,492 miles.
C. 4,686 miles.
D. 485 miles.
D
What frequency band is used by the Iridium system for telephone and messaging?
A. 965 - 985 MHz.
B. 1616 -1626 MHz.
C. 1855 -1895 MHz.
D. 2415 - 2435 MHz.
B
What services are provided by the Iridium system?
A. Analog voice and Data at 4.8 kbps.
B. Digital voice and Data at 9.6 kbps.
C. Digital voice and Data at 2.4 kbps.
D. Analog voice and Data at 9.6 kbps.
C
Which of the following statements about the Iridium system is true?
A. There are 48 spot beams per satellite with a footprint of 30 miles in diameter.
B. There are 48 satellites in orbit in 4 orbital planes.
C. The inclination of the orbital planes is 55 degrees.
D. The orbital period is approximately 85 minutes.
A
What is the main function of the COSPAS-SARSAT satellite system?
A. Monitor 121.5 MHz for voice distress calls.
B. Monitor 406 MHz for distress calls from EPIRBs.
C. Monitor 1635 MHz for coded distress calls.
D. Monitor 2197.5 kHz for hexadecimal coded DSC distress messages.
B
How does the COSPAS-SARSAT satellite system determine the position of a ship in distress?
A. By measuring the Doppler shift of the 406 MHz signal taken at several different points in its orbit.
B. The EPIRB always transmits its position which is relayed by the satellite to the Local User Terminal.
C. It takes two different satellites to establish an accurate position.
D. None of the above.
A
What is the orbital altitude of INMARSAT Satellites?
A. 16, 436 miles.
B. 22,177 miles.
C. 10, 450 miles.
D. 26,435 miles.
B
Which of the following describes the INMARSAT Satellite system?
A. AOR at 35° W, POR-E at 165° W, POR-W at 155° E and IOR at 56.5° E.
B. AOR-E at 25° W, AOR-W at 85° W, POR at 175° W and IOR at 56.5° E.
C. AOR-E at 15.5° W, AOR-W at 54° W, POR at 178° E and IOR at 64.5° E.
D. AOR at 40° W, POR at 178° W, IOR-E at 109° E and IOR-W at 46° E.
C
What are the directional characteristics of the INMARSAT-C SES antenna?
A. Highly directional parabolic antenna requiring stabilization.
B. Wide beam width in a cardioid pattern off the front of the antenna.
C. Very narrow beam width straight-up from the top of the antenna.
D. Omnidirectional.
D
When engaging in voice communications via an INMARSAT-B terminal, what techniques are used?
A. CODECs are used to digitize the voice signal.
B. Noise-blanking must be selected by the operator.
C. The voice signal must be compressed to fit into the allowed bandwidth.
D. The voice signal will be expanded at the receiving terminal.
A
Which of the following statements concerning INMARSAT geostationary satellites is true?
A. They are in a polar orbit, in order to provide true global coverage.
B. They are in an equatorial orbit, in order to provide true global coverage.
C. They provide coverage to vessels in nearly all of the world’s navigable waters.
D. Vessels sailing in equatorial waters are able to use only one satellite, whereas other vessels are able to choose between at least two satellites.
C
Which of the following conditions can render INMARSAT -B communications impossible?
A. An obstruction, such as a mast, causing disruption of the signal between the satellite and the SES antenna when the vessel is steering a certain course.
B. A satellite whose signal is on a low elevation, below the horizon.
C. Travel beyond the effective radius of the satellite.
D. All of these.
D
What is the best description for the INMARSAT-C system?
A. It provides slow speed telex and voice service.
B. It is a store-and-forward system that provides routine and distress communications.
C. It is a real-time telex system.
D. It provides world-wide coverage.
B
The INMARSAT mini-M system is a:
A. Marine SONAR system.
B. Marine global satellite system.
C. Marine depth finder.
D. Satellite system utilizing spot beams to provide for small craft communications.
D
What statement best describes the INMARSAT-B services?
A. Voice at 16 kbps, Fax at 14.4 kbps and high-speed Data at 64/54.
B. Store and forward high speed data at 36/48 kbps.
C. Voice at 3 kHz, Fax at 9.6 kbps and Data at 4.8 kbps.
D. Service is available only in areas served by highly directional spot beam antennas.
A