U.S. Non-Federal-Government Allocations
MARITIME RADIONAVIGATION (radiobeacons) 5.73
Aeronautical radionavigation (radiobeacons)
SpectrumWiki
Radio spectrum allocations
Look up a frequency or a range.
Examples: 88.5 MHz, 1350–1430 MHz, 2.4 GHz
314.999 kHz (314,999 Hz)
U.S. Federal Government Allocations
MARITIME RADIONAVIGATION (radiobeacons) 5.73
Aeronautical radionavigation (radiobeacons)
ITU Region 1 Allocations
AERONAUTICAL RADIONAVIGATION
MARITIME RADIONAVIGATION (radiobeacons) 5.73
ITU Region 2 Allocations
AERONAUTICAL RADIONAVIGATION
Maritime radionavigation (radiobeacons) 5.73
ITU Region 3 Allocations
AERONAUTICAL RADIONAVIGATION
Maritime radionavigation (radiobeacons) 5.73
Footnotes
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5.73 The band 285-325 kHz (283.5-325 kHz in Region 1) in the maritime radionavigation service may be used to transmit supplementary navigational information using narrow-band techniques, on condition that no harmful interference is caused to radiobeacon stations operating in the radionavigation service. (WRC-97)
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5.74 Additional allocation: in Region 1, the frequency band 285.3-285.7 kHz is also allocated to the maritime radionavigation service (other than radiobeacons) on a primary basis.
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US2 In the band 9-490 kHz, electric utilities operate Power Line Carrier (PLC) systems on power transmission lines for communications important to the reliability and security of electric service to the public. These PLC systems operate under the provisions of 47 CFR part 15, or Chapter 8 of the NTIA Manual, on an unprotected and non-interference basis with respect to authorized radio users. Notification of intent to place new or revised radio frequency assignments or PLC frequency uses in the band 9-490 kHz is to be made in accordance with the Rules and Regulations of the FCC and NTIA, and users are urged to minimize potential interference to the extent practicable. This footnote does not provide any allocation status to PLC radio frequency uses.
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US18 In the bands 9-14 kHz, 90-110 kHz, 190-415 kHz, 510-535 kHz, and 2700-2900 MHz, navigation aids in the U.S. and its insular areas are normally operated by the Federal Government. However, authorizations may be made by the FCC for non-Federal operations in these bands subject to the conclusion of appropriate arrangements between the FCC and the Federal agencies concerned and upon special showing of need for service which the Federal Government is not yet prepared to render.
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US364 Consistent with US18, stations may be authorized on a primary basis in the band 285-325 kHz for the specific purpose of transmitting differential global positioning system information.
Wiki entries
Aeronautical Nondirectional Radiobeacons (NDBs)
Current Use
285–325 kHz Aeronautical NDBs (secondary to maritime radiobeacons)
According to the U.S. Federal Radionavigation Plan (2010):
NDB serve as nonprecision approach aids at some airports; as compass locators, generally collocated with the outer marker of an ILS to assist pilots in getting on the ILS course in a non-radar environment; and as en route navigation aids.
The NAS includes more than 1,300 NDB. Fewer than 300 are owned by the Federal Government; the rest are non-Federal facilities owned predominately by state, municipal, and airport authorities.
FAA has begun decommissioning stand-alone NDB as users equip with GPS. NDB used as compass locators, or as other required fixes for ILS approaches (e.g., initial approach fix, missed approach holding), where no equivalent ground-based means are available, may need to be maintained until the underlying ILS is phased out. Most NDB that define low- frequency airways in Alaska or serve international gateways and certain offshore areas like the Gulf of Mexico will be retained.
Except in Alaskan airspace, no future civil aeronautical uses are envisioned for these bands after the aeronautical NDB system has been decommissioned throughout the rest of the NAS. Marine radiobeacons have been phased out.
...
Further information from the Radionavigation Plan:
Radiobeacons are nondirectional radio transmitting stations that operate in the low- and medium-frequency bands to provide ground wave signals to a receiver. Aeronautical nondirectional beacons are used to supplement VOR-DME for transition from en route to airport precision approach facilities and as a nonprecision approach aid at many airports. An automatic direction finder (ADF) is used to measure the bearing of the transmitter with respect to an aircraft or vessel. Marine radiobeacons have been phased out.
A. Signal Characteristics
Aeronautical NDB operate in the 190 to 415 kHz and 510 to 535 kHz ARNS bands. (Note: NDB in the 285-325 kHz band are secondary to maritime radiobeacons.) Their transmissions include a coded continuous- wave (CCW) or modulated continuous-wave (MCW) signal to identify the station. The CCW signal is generated by modulating a single carrier with either a 400 Hz or a 1,020 Hz tone for Morse code identification. The MCW signal is generated by spacing two carriers either 400 Hz or 1,020 Hz apart and keying the upper carrier to give the Morse code identification.
B. Accuracy
Positional accuracy derived from the bearing information is a function of geometry of the Lines of Position (LOP), the accuracy of compass heading, measurement accuracy, distance from the transmitter, stability of the signal, time of day, nature of the terrain between beacon and craft, and noise. In practice, bearing accuracy is on the order of +/-3 to +/-10 deg. Achievement of +/-3 deg accuracy requires that the ADF be calibrated before it is used for navigation by comparing radio bearings to accurate bearings obtained visually on the transmitting antenna. Since most direction finder receivers will tune to a number of radio frequency bands, transmissions from sources of known location, such as amplitude modulation (AM) broadcast stations, are also used to obtain bearings, generally with less accuracy than obtained from radiobeacon stations. For FAA flight inspection, NDB system accuracy is stated in terms of permissible needle swing: ±5 deg on approaches and +/-10 deg in the en route area.
C. Availability
Availability of Aeronautical NDB is in excess of 99%.
D. Coverage
Extensive NDB coverage is provided by 1,575 ground stations, of which FAA operates 728.
E. Reliability
Reliability is in excess of 99%.
F. Fix Interval
The beacon provides continuous bearing information.
G. Fix Dimensions
In general, one LOP is available from a single radiobeacon. If within range of two or more beacons, a two-dimensional fix may be obtained.
H. System Capacity
An unlimited number of receivers may be used simultaneously.
I. Ambiguity
The only ambiguity that exists in the radiobeacon system is one of reciprocal bearing provided by some receiving equipment that does not employ a sense antenna to resolve direction.
J. Integrity
A radiobeacon is an omnidirectional navigation aid. For aviation radiobeacons, out-of-tolerance conditions are limited to output power reduction below operating minimums and loss of the transmitted station identifying tone. The radiobeacons used for nonprecision approaches are monitored and will shut down within 15 s of an out-of-tolerance condition.
K. Spectrum
Aeronautical NDB operate in the 190-435 and 510-535 kHz frequency bands, portions of which it shares with maritime NDB.
NDB serve as nonprecision approach aids at some airports; as compass locators, generally collocated with the outer marker of an ILS to assist pilots in getting on the ILS course in a non-radar environment; and as en route navigation aids.
The NAS includes more than 1,300 NDB. Fewer than 300 are owned by the Federal Government; the rest are non-Federal facilities owned predominately by state, municipal, and airport authorities.
FAA has begun decommissioning stand-alone NDB as users equip with GPS. NDB used as compass locators, or as other required fixes for ILS approaches (e.g., initial approach fix, missed approach holding), where no equivalent ground-based means are available, may need to be maintained until the underlying ILS is phased out. Most NDB that define low- frequency airways in Alaska or serve international gateways and certain offshore areas like the Gulf of Mexico will be retained.
Except in Alaskan airspace, no future civil aeronautical uses are envisioned for these bands after the aeronautical NDB system has been decommissioned throughout the rest of the NAS. Marine radiobeacons have been phased out.
...
Further information from the Radionavigation Plan:
Radiobeacons are nondirectional radio transmitting stations that operate in the low- and medium-frequency bands to provide ground wave signals to a receiver. Aeronautical nondirectional beacons are used to supplement VOR-DME for transition from en route to airport precision approach facilities and as a nonprecision approach aid at many airports. An automatic direction finder (ADF) is used to measure the bearing of the transmitter with respect to an aircraft or vessel. Marine radiobeacons have been phased out.
A. Signal Characteristics
Aeronautical NDB operate in the 190 to 415 kHz and 510 to 535 kHz ARNS bands. (Note: NDB in the 285-325 kHz band are secondary to maritime radiobeacons.) Their transmissions include a coded continuous- wave (CCW) or modulated continuous-wave (MCW) signal to identify the station. The CCW signal is generated by modulating a single carrier with either a 400 Hz or a 1,020 Hz tone for Morse code identification. The MCW signal is generated by spacing two carriers either 400 Hz or 1,020 Hz apart and keying the upper carrier to give the Morse code identification.
B. Accuracy
Positional accuracy derived from the bearing information is a function of geometry of the Lines of Position (LOP), the accuracy of compass heading, measurement accuracy, distance from the transmitter, stability of the signal, time of day, nature of the terrain between beacon and craft, and noise. In practice, bearing accuracy is on the order of +/-3 to +/-10 deg. Achievement of +/-3 deg accuracy requires that the ADF be calibrated before it is used for navigation by comparing radio bearings to accurate bearings obtained visually on the transmitting antenna. Since most direction finder receivers will tune to a number of radio frequency bands, transmissions from sources of known location, such as amplitude modulation (AM) broadcast stations, are also used to obtain bearings, generally with less accuracy than obtained from radiobeacon stations. For FAA flight inspection, NDB system accuracy is stated in terms of permissible needle swing: ±5 deg on approaches and +/-10 deg in the en route area.
C. Availability
Availability of Aeronautical NDB is in excess of 99%.
D. Coverage
Extensive NDB coverage is provided by 1,575 ground stations, of which FAA operates 728.
E. Reliability
Reliability is in excess of 99%.
F. Fix Interval
The beacon provides continuous bearing information.
G. Fix Dimensions
In general, one LOP is available from a single radiobeacon. If within range of two or more beacons, a two-dimensional fix may be obtained.
H. System Capacity
An unlimited number of receivers may be used simultaneously.
I. Ambiguity
The only ambiguity that exists in the radiobeacon system is one of reciprocal bearing provided by some receiving equipment that does not employ a sense antenna to resolve direction.
J. Integrity
A radiobeacon is an omnidirectional navigation aid. For aviation radiobeacons, out-of-tolerance conditions are limited to output power reduction below operating minimums and loss of the transmitted station identifying tone. The radiobeacons used for nonprecision approaches are monitored and will shut down within 15 s of an out-of-tolerance condition.
K. Spectrum
Aeronautical NDB operate in the 190-435 and 510-535 kHz frequency bands, portions of which it shares with maritime NDB.
Nationwide Differential GPS (NDGPS) System
Current Use
285–325 kHz NDGPS Broadcasts on Marine Radiobeacons
The U.S. Coast Guard's Navigation Center (NAVCEN) operates maritime radiobeacons in the 285-325 kHz band that include a digital data broadcast of differential GPS corrections. These beacon signals are part of the Nationwide Differential GPS (NDGPS) Service. The system consists of one control site and 86 remote broadcast sites, which formally occupy center frequencies ranging from 286 to 325 kHz. The links below include a list of all broadcast sites.
According to the Coast Guard: "NAVCEN operates the Coast Guard Maritime Differential GPS (DGPS) Service and the developing Nationwide DGPS Service, consisting of one control center and 86 remote broadcast sites. The Service broadcasts correction signals on marine radiobeacon frequencies to improve the accuracy and integrity to GPS-derived positions. The Coast Guard DGPS Service provides 10-meter accuracy in all established coverage areas."
According to the Coast Guard: "NAVCEN operates the Coast Guard Maritime Differential GPS (DGPS) Service and the developing Nationwide DGPS Service, consisting of one control center and 86 remote broadcast sites. The Service broadcasts correction signals on marine radiobeacon frequencies to improve the accuracy and integrity to GPS-derived positions. The Coast Guard DGPS Service provides 10-meter accuracy in all established coverage areas."