Non-Directional Beacons
E586555
Non-directional beacons are ground-based radio transmitters that emit signals in all directions to help aircraft determine their bearing and navigate, especially in low-visibility conditions.
All labels observed (3)
| Label | Occurrences |
|---|---|
| NDB | 1 |
| NDB LLS | 1 |
| Non-Directional Beacons canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T6327301 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Non-Directional Beacons Context triple: [Aviation Navigation, includesTechnology, Non-Directional Beacons]
-
A.
TACAN
TACAN is a military tactical air navigation system that provides aircraft with precise bearing and distance information to a ground station.
-
B.
Knickebein radio navigation system
The Knickebein radio navigation system was a World War II German Luftwaffe beam-guidance technology used to direct bombers accurately to their targets at night and in poor visibility.
-
C.
NDB
NDB is a multilateral development bank established by the BRICS countries to finance infrastructure and sustainable development projects in emerging economies.
-
D.
LORAN
LORAN is a long-range terrestrial radio navigation system originally developed for maritime and aviation positioning before the advent of satellite-based GPS.
-
E.
VOR/DME
VOR/DME is a ground-based radio navigation system that provides aircraft with both bearing and distance information to aid en-route and approach navigation.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Non-Directional Beacons Target entity description: Non-directional beacons are ground-based radio transmitters that emit signals in all directions to help aircraft determine their bearing and navigate, especially in low-visibility conditions.
-
A.
TACAN
TACAN is a military tactical air navigation system that provides aircraft with precise bearing and distance information to a ground station.
-
B.
Knickebein radio navigation system
The Knickebein radio navigation system was a World War II German Luftwaffe beam-guidance technology used to direct bombers accurately to their targets at night and in poor visibility.
-
C.
NDB
NDB is a multilateral development bank established by the BRICS countries to finance infrastructure and sustainable development projects in emerging economies.
-
D.
LORAN
LORAN is a long-range terrestrial radio navigation system originally developed for maritime and aviation positioning before the advent of satellite-based GPS.
-
E.
VOR/DME
VOR/DME is a ground-based radio navigation system that provides aircraft with both bearing and distance information to aid en-route and approach navigation.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
aeronautical radio navigation service
ⓘ
ground-based navigation aid ⓘ radio navigation aid ⓘ |
| abbreviation | NDB ⓘ |
| beingReplacedBy |
area navigation procedures
ⓘ
satellite navigation systems ⓘ |
| canBeLocatedAt |
near airways
ⓘ
off-airport remote site ⓘ on an airport ⓘ |
| category | aviation navigation infrastructure ⓘ |
| comparedWith | VHF Omnidirectional Range ⓘ |
| coverageType | line-of-sight limited by ground-wave propagation ⓘ |
| emits | radio signal in all directions ⓘ |
| frequencyBand |
low frequency band
ⓘ
medium frequency band ⓘ |
| hasLimitation |
less accurate than VOR
ⓘ
susceptible to atmospheric interference ⓘ susceptible to coastal refraction ⓘ susceptible to night effect ⓘ |
| hasVariant |
locator middle marker
ⓘ
locator outer marker ⓘ |
| introducedIn | early 20th century ⓘ |
| modulation | amplitude modulation ⓘ |
| navigationPrinciple | bearing determined by relative bearing to station ⓘ |
| operatesIn |
instrument meteorological conditions
ⓘ
low-visibility conditions ⓘ |
| powerLevel |
higher-power for en‑route NDB
ⓘ
low-power for terminal NDB ⓘ |
| receivedBy |
ADF receiver in aircraft
ⓘ
automatic direction finder ⓘ |
| regulatedBy |
Federal Aviation Administration
ⓘ
International Civil Aviation Organization ⓘ |
| relatedTo | instrument landing system ⓘ |
| requires | magnetic compass for bearing calculation ⓘ |
| signalType | continuous wave ⓘ |
| stillUsedIn | many regions worldwide ⓘ |
| supportsInstrumentProcedure |
NDB approach
ⓘ
NDB holding pattern ⓘ |
| transmits | Morse code station identifier ⓘ |
| typicalFrequencyRange | 190–535 kHz ⓘ |
| usedBy |
aircraft
ⓘ
pilots ⓘ |
| usedFor |
aircraft navigation
ⓘ
approach procedures ⓘ bearing determination ⓘ en‑route navigation ⓘ holding patterns ⓘ |
| uses | non-directional radio transmission ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Non-Directional Beacons Description of subject: Non-directional beacons are ground-based radio transmitters that emit signals in all directions to help aircraft determine their bearing and navigate, especially in low-visibility conditions.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Non-Directional Beacons
linked to: Non-Directional Beacons