GPS and electronic navigation
Satellite navigation: the GPS receiver a vessel calling at a US port must carry, automatic acquisition of satellite signals and position updates on each usable pass, and the Automatic Identification System — who must carry AIS, what it transmits and how often.
Appears on 45% of examsDifficulty 2/550 drill questions
On the paperQ171 / Q35750 questions70% to pass, 15 wrong allowed
Authoritative sources#
Every answer on this topic traces back to the public rule corpus below.
Source excerpts#
Bowditch Pub. 9 Ch. 22 §2208
GPS Receiver Operations In order for the GPS receiver to navigate, it has to track satellite signals, make pseudorange measurements, and collect navigation data. A typical satellite tracking sequence begins with the receiver determining which satellites are available for it to track. Satellite visibility is determined by user-entered predictions of position, velocity, and time, and by almanac information stored internal to the receiver. If no stored almanac information exists, then the receiver must attempt to locate and lock onto the signal from any satellite in view. When the receiver is locked onto a satellite, it can demodulate the navigation message and read the almanac information about all the other satellites in the constellation. A carrier tracking loop tracks the carrier frequen…
Bowditch Pub. 9 Ch. 29 §2907 ¶1
Description and Purpose Vessel Traffic Services in the U.S. are implemented under the authority of the Ports and Waterways Safety Act of 1972 (Public Law 92-340 as amended) and the St. Lawrence Seaway Act (Public Law 358). The purpose of a Vessel Traffic Service (VTS) is to provide active monitoring and navigational advice for vessels in particularly confined and busy waterways. There are two main types of VTS, surveilled and non-surveilled. Surveilled systems consist of one or more land-based sensors (i.e. radar, AIS and closed circuit television sites), which output their signals to a central location where operators monitor and manage vessel traffic movement. Non-surveilled systems consist of one or more reporting points at which ships are required to report their identity, course, spe…
Bowditch Pub. 9 Ch. 29 §2907 ¶2
Description and Purpose 458 NAVIGATION REGULATIONS ational tests of several Universal AIS (ITU-R M.1371) precursors. The most comprehensive test bed has been on the Lower Mississippi River. AIS is discussed in greater detail in Chapter 30. The Nationwide Automatic Identification System (NAIS) consists of approximately 200 VHF receiver sites located throughout the coastal continental United States, inland rivers, Alaska, Hawaii and Guam. NAIS is designed to collect AIS transmissions from local vessels. Currently, NAIS collects valuable maritime data in 58 critical ports throughout the United States for use by Coast Guard operators and port partners. The primary goal of NAIS is to increase Maritime Domain Awareness (MDA) through data dissemination via a network infrastructure, particularly …
Bowditch Pub. 9 Ch. 30 §3018
Development and Purpose Automatic Identification System (AIS) is a navigation-communication protocol used in the maritime Figure 3016a. COSPAS-SARSAT System Overview. (1) Emergency locater transmitters (ELTs), EPIRBs, and personal locater beacons (PLBs) operate on the 406 MHz frequency. Each 406 MHz beacon transmits a unique digital code that identifies the type of beacon and that allows registration data to be associated with the beacon. The registration data provides information such as the beacon owner; the type of platform the beacon is associated with; emergency points of contact; and much more. (2) After the satellite receives a beacon signal, it relays the signal to ground stations referred to as local user terminals (LUTs). There are two types of LUTs: Low-Earth Orbiting LUTs (LEO…
33 CFR §164.01
Applicability. (a) This part (except as specifically limited by this section) applies to each self-propelled vessel of 1600 or more gross tons (except as provided in paragraphs (c) and (d) of this section, or for foreign vessels described in § 164.02) when it is operating in the navigable waters of the United States except the St. Lawrence Seaway. (b) Sections 164.70 through 164.82 of this part apply to each towing vessel of 12 meters (39.4 feet) or more in length operating in the navigable waters of the United States other than the St. Lawrence Seaway; except that a towing vessel is exempt from the requirements of § 164.72 if it is— (1) Used solely within a limited geographic area, such as a fleeting-area for barges or a commercial facility, and used solely for restricted service, such…
33 CFR §164.02
Applicability exception for foreign vessels. (a) Except for § 164.46(c), none of the requirements of this part apply to foreign vessels that: (1) Are not destined for, or departing from, a port or place subject to the jurisdiction of the United States; and (2) Are in: (i) Innocent passage through the territorial sea of the United States; or (ii) Transit through navigable waters of the United States which form a part of an international strait. [CGD 77-063, 44 FR 66530, Nov. 19, 1979, as amended by CGD 79-148, 45 FR 54039, Aug. 14, 1980; USCG-2003-14757, 68 FR 39367, July 1, 2003; 68 FR 60569, Oct. 22, 2003; USCG-2005-21869, 80 FR 5334, Jan. 30, 2015]
Practice this topic#
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In confined waters where dead reckoning alone is insufficient, which navigation method is considered primary?
Study this topic#
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