Bessel ellipsoid
E579588
The Bessel ellipsoid is a historical reference ellipsoid of the Earth defined in the 19th century for geodetic and cartographic purposes, particularly in Europe.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Bessel ellipsoid canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T6250942 — 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: Bessel ellipsoid Context triple: [Friedrich Bessel, notableFor, Bessel ellipsoid]
-
A.
Airy 1830 ellipsoid
The Airy 1830 ellipsoid is a reference ellipsoid defined in the 19th century for geodetic calculations in Great Britain, forming the basis of traditional mapping systems such as the British National Grid.
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B.
Airy Modified ellipsoid
The Airy Modified ellipsoid is a slightly adjusted version of the Airy ellipsoid used as the reference surface for mapping and geodetic calculations in systems such as the Irish grid reference system.
-
C.
Roche ellipsoid
A Roche ellipsoid is an equilibrium shape assumed by a self-gravitating fluid body that is tidally distorted by a nearby massive companion, important in the study of close binary systems and tidal interactions.
-
D.
Maclaurin spheroid
A Maclaurin spheroid is an oblate, rotationally symmetric ellipsoidal figure used in astrophysics and geophysics to model the equilibrium shape of a uniformly rotating, self-gravitating fluid body.
-
E.
Jacobi ellipsoid
A Jacobi ellipsoid is a rotating, self-gravitating fluid body in equilibrium that takes on a triaxial ellipsoidal shape due to its rapid spin.
- 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Target entity: Bessel ellipsoid Target entity description: The Bessel ellipsoid is a historical reference ellipsoid of the Earth defined in the 19th century for geodetic and cartographic purposes, particularly in Europe.
-
A.
Airy 1830 ellipsoid
The Airy 1830 ellipsoid is a reference ellipsoid defined in the 19th century for geodetic calculations in Great Britain, forming the basis of traditional mapping systems such as the British National Grid.
-
B.
Airy Modified ellipsoid
The Airy Modified ellipsoid is a slightly adjusted version of the Airy ellipsoid used as the reference surface for mapping and geodetic calculations in systems such as the Irish grid reference system.
-
C.
Roche ellipsoid
A Roche ellipsoid is an equilibrium shape assumed by a self-gravitating fluid body that is tidally distorted by a nearby massive companion, important in the study of close binary systems and tidal interactions.
-
D.
Maclaurin spheroid
A Maclaurin spheroid is an oblate, rotationally symmetric ellipsoidal figure used in astrophysics and geophysics to model the equilibrium shape of a uniformly rotating, self-gravitating fluid body.
-
E.
Jacobi ellipsoid
A Jacobi ellipsoid is a rotating, self-gravitating fluid body in equilibrium that takes on a triaxial ellipsoidal shape due to its rapid spin.
- F. None of above. chosen
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
Earth ellipsoid
ⓘ
geodetic datum component ⓘ reference ellipsoid ⓘ |
| accuracyContext | local best-fit rather than global best-fit ⓘ |
| application |
geodesy
ⓘ
map projection definition ⓘ surveying ⓘ |
| category | European reference ellipsoid ⓘ |
| comparedTo |
Clarke 1866 ellipsoid
ⓘ
Hayford 1909 ellipsoid ⓘ |
| computationBasis |
astronomical observations
ⓘ
geodetic measurements ⓘ |
| coordinateSystemUse | geodetic coordinates (latitude, longitude, ellipsoidal height) ⓘ |
| datumRealization | local best-fit to Europe ⓘ |
| datumUse |
Asian geodetic networks
ⓘ
European geodetic networks ⓘ |
| definedBy |
Friedrich Wilhelm Bessel
ⓘ
linked to:
Friedrich Bessel
|
| definitionYear | 1841 ⓘ |
| epoch | 19th century ⓘ |
| flattening | 0.003342773182 ⓘ |
| geometryType | rotational ellipsoid ⓘ |
| historicalImportance | one of the first rigorously computed Earth ellipsoids ⓘ |
| inverseFlattening | 299.1528128 ⓘ |
| namedAfter |
Friedrich Wilhelm Bessel
ⓘ
linked to:
Friedrich Bessel
|
| parameterSet | semi-major axis and flattening ⓘ |
| referenceBody | Earth ⓘ |
| regionOfBestFit |
Central Europe
ⓘ
Europe ⓘ |
| replacedBy |
GRS80 ellipsoid
ⓘ
linked to:
GRS80
WGS84 ellipsoid ⓘ
linked to:
WGS84
|
| semiMajorAxis | 6377397.155 m ⓘ |
| semiMinorAxis | 6356078.963 m ⓘ |
| status | historical ⓘ |
| surfaceType | oblate spheroid ⓘ |
| unitOfParameters | metre ⓘ |
| usedFor |
cartography
ⓘ
topographic mapping ⓘ triangulation networks ⓘ |
| usedIn |
Austrian geodetic surveys
ⓘ
German geodetic datum ⓘ Japanese geodetic datum (Tokyo datum) ⓘ Nordic geodetic systems (historical) ⓘ Prussian geodetic surveys ⓘ |
| usedUntil | late 20th century in some national systems ⓘ |
| usedWithProjection |
Gauss–Krüger projection
ⓘ
linked to:
Transverse Mercator
Transverse Mercator projection ⓘ
linked to:
Transverse Mercator
|
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: Bessel ellipsoid Description of subject: The Bessel ellipsoid is a historical reference ellipsoid of the Earth defined in the 19th century for geodetic and cartographic purposes, particularly in Europe.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.