NAVD 88
E244556
NAVD 88 is the current official vertical datum used across the United States to provide a consistent reference for measuring elevations.
All labels observed (2)
How this entity was disambiguated
This entity first appeared as the object of triple T2209727 — 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: NAVD 88 Context triple: [National Spatial Reference System, historicalComponent, NAVD 88]
-
A.
NADC
NADC is the abbreviation for the National Australia Day Council, the organization responsible for promoting and coordinating Australia Day celebrations and related national identity initiatives.
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B.
NHPA
NHPA is a landmark U.S. federal law that established the framework for preserving historic buildings, sites, and cultural resources nationwide.
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C.
NHA
NHA is the commonly used abbreviation for the National Hockey Association, a historic professional ice hockey league that operated in Canada in the early 20th century.
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D.
NCTC
NCTC is the U.S. government’s primary organization for integrating and analyzing terrorism-related intelligence and coordinating counterterrorism efforts across agencies.
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E.
Defense Manpower Data Center
The Defense Manpower Data Center is a U.S. Department of Defense organization responsible for managing and securing personnel, pay, and benefits data for service members, veterans, and their families.
- 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: NAVD 88 Target entity description: NAVD 88 is the current official vertical datum used across the United States to provide a consistent reference for measuring elevations.
-
A.
NADC
NADC is the abbreviation for the National Australia Day Council, the organization responsible for promoting and coordinating Australia Day celebrations and related national identity initiatives.
-
B.
NHPA
NHPA is a landmark U.S. federal law that established the framework for preserving historic buildings, sites, and cultural resources nationwide.
-
C.
NHA
NHA is the commonly used abbreviation for the National Hockey Association, a historic professional ice hockey league that operated in Canada in the early 20th century.
-
D.
NCTC
NCTC is the U.S. government’s primary organization for integrating and analyzing terrorism-related intelligence and coordinating counterterrorism efforts across agencies.
-
E.
Defense Manpower Data Center
The Defense Manpower Data Center is a U.S. Department of Defense organization responsible for managing and securing personnel, pay, and benefits data for service members, veterans, and their families.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
geodetic datum
ⓘ
vertical datum ⓘ |
| abbreviation | NAVD 88 ⓘ |
| adoptedBy |
National Geodetic Survey
ⓘ
National Oceanic and Atmospheric Administration ⓘ |
| adoptedYear | 1991 ⓘ |
| alsoKnownAs |
NGVD 88
ⓘ
linked to:
National Geodetic Vertical Datum of 1929
|
| associatedWith | GEOID models ⓘ |
| coordinateReferenceFrameRelation | compatible with NAD 83 horizontal datum ⓘ |
| coordinateSystem |
North American National Spatial Reference System
ⓘ
linked to:
National Spatial Reference System
|
| countryUsedIn |
Canada
ⓘ
Mexico ⓘ United States ⓘ
linked to:
United States of America
|
| datumType | fixed-height datum ⓘ |
| definedBy | constrained least-squares adjustment of leveling observations ⓘ |
| fullName | North American Vertical Datum of 1988 ⓘ |
| heightType | orthometric height ⓘ |
| knownIssue |
regional height biases
ⓘ
subsidence effects on benchmarks ⓘ tilt relative to modern geoid models ⓘ |
| maintainedBy | National Geodetic Survey ⓘ |
| numberOfBenchmarksUsed | over 600000 ⓘ |
| officiallyImplementedYear | 1993 ⓘ |
| partOf | National Spatial Reference System ⓘ |
| realizationMethod | spirit leveling network ⓘ |
| referenceSurfaceType | orthometric height reference ⓘ |
| referenceTideGauge | Father Point/Rimouski tide gauge ⓘ |
| referenceTideGaugeLocation | Rimouski, Quebec, Canada ⓘ |
| referenceTideGaugeType | primary tidal benchmark ⓘ |
| referenceTo | geoid ⓘ |
| replaced | National Geodetic Vertical Datum of 1929 ⓘ |
| replacementPlannedBy | National Geodetic Survey ⓘ |
| replacementReason | to improve accuracy using GNSS and gravimetric geoid models ⓘ |
| scope |
Alaska
ⓘ
Hawaii (limited applications) ⓘ U.S. territories (limited applications) ⓘ continental United States ⓘ
linked to:
contiguous United States
|
| successorPlannedName | NAPGD2022 ⓘ |
| usedFor |
coastal zone management
ⓘ
engineering design ⓘ floodplain management ⓘ hydrologic modeling ⓘ infrastructure construction ⓘ topographic mapping ⓘ |
| usedIn |
Federal Emergency Management Agency flood maps
ⓘ
US Geological Survey topographic maps ⓘ transportation infrastructure design standards ⓘ |
| willBeReplacedBy | North American-Pacific Geopotential Datum of 2022 ⓘ |
| zeroDefinition | height of primary tidal benchmark at Rimouski ⓘ |
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: NAVD 88 Description of subject: NAVD 88 is the current official vertical datum used across the United States to provide a consistent reference for measuring elevations.
Referenced by (8)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: NAVD 88