How GEIPAN Determines Identified and Probable Cases

Introduction

Within France’s public UFO and UAP database, GEIPAN’s A and B categories are the mechanism used to distinguish sightings that have a plausible conventional explanation from those that remain unresolved. An A classification means investigators consider the phenomenon identified with a very high degree of confidence. A B classification means the most likely explanation has been found, but some uncertainty remains because the available evidence is incomplete or does not allow absolute confirmation. GEIPAN uses these categories to separate cases that are effectively resolved from those that lack sufficient information or remain unexplained after investigation. [Geipan]geipan.frGeipanRecherche de cas[A750] DE AUMELAS (34) VERS GIGNAC (34) 04.12.2021, 04/12/2021, B; [A86] DE SCEAUX (92) VERS PARIS (75) 01.11.2021…

For readers exploring UFO report databases and catalogues, the key point is that neither A nor B indicates an unknown phenomenon. Both categories represent cases where investigators believe a known cause best explains what witnesses reported. The difference lies in the strength of the identification rather than in the type of phenomenon involved. [Geipan]geipan.frRecherche de casThe Geipan. Mission & Geipan · Its history · Documentation · Events · Actualities; Cases & Testimonials. Case search · St…

Definition of A and B Categories

GEIPAN formally defines the categories as follows:

[* A: Phenomenon perfectly identified after investigation.]cnes-geipan.frSource details in endnotes. * B: Phenomenon probably identified after investigation. Geipan [cnes-geipan.fr]cnes-geipan.frSource details in endnotes.

The distinction is subtle but important. An A case is one in which the investigation produces a near-certain match between the reported observation and a known object, event, or natural phenomenon. A B case reaches a probable explanation, but investigators cannot eliminate all alternative possibilities with the available evidence. [Geipan]geipan.frRecherche de casThe Geipan. Mission & Geipan · Its history · Documentation · Events · Actualities; Cases & Testimonials. Case search · St…

Examples of explanations that commonly lead to A or B classifications include:

GEIPAN’s published statistics show that the majority of resolved cases fall into the A or B categories, with many arising from misidentifications or perceptual errors rather than genuinely unusual aerial phenomena. [Geipan]geipan.frRecherche de casThe Geipan. Mission & Geipan · Its history · Documentation · Events · Actualities; Cases & Testimonials. Case search · St…

How GEIPAN Decides Between Identified and Probably Identified

Since 2008, GEIPAN has used a more formal classification method based on two concepts: residual strangeness and consistency. These are not measures of how exciting a sighting is; they are tools for judging how well an explanation fits the evidence. [Geipan]geipan.frRecherche de casThe Geipan. Mission & Geipan · Its history · Documentation · Events · Actualities; Cases & Testimonials. Case search · St… [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

Residual Strangeness

Investigators begin by generating possible explanations for the reported event. These explanations may involve physical causes, such as astronomical objects or atmospheric phenomena, or human factors, such as perception effects and memory errors. They then estimate which explanation best fits the available evidence. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

GEIPAN defines strangeness as the distance from the strongest known explanation. If the best hypothesis appears highly probable, residual strangeness is low. If no convincing explanation emerges, residual strangeness becomes high. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

Consistency of the Evidence

Consistency reflects the quality and reliability of the information available. Investigators consider factors such as:

A case supported by multiple independent witnesses and objective evidence is considered more consistent than a brief report from a single observer with limited details. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

When a Case Becomes A Rather Than B

The crucial difference lies in the confidence level attached to the explanation.

An A classification is used when the evidence effectively confirms the explanation. GEIPAN’s own methodology describes A cases as those where the explanatory hypothesis is close to being proven. A B classification is used when the explanation is judged probable but not fully demonstrated. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

In practical terms:

SituationLikely ClassificationStrong evidence directly matches a known causeAKnown cause fits well but some uncertainty remainsBExplanation cannot be tested because information is insufficientCNo satisfactory explanation survives investigationD1 or D2

This framework prevents investigators from treating every unresolved detail as a mystery while also avoiding overconfident conclusions when the evidence is incomplete. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

Example Resolved Cases

GEIPAN’s public database provides many examples of A and B classifications that illustrate how the distinction works in practice.

Starlink Satellite Flashes

Several aviation-related observations from 2023 were classified as A cases after investigators linked the reported lights to reflections from Starlink satellites. The satellite explanation matched the timing, location and observed characteristics closely enough for GEIPAN to treat the identification as effectively established. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

These cases demonstrate the role of modern tracking data. As satellite constellations have expanded, some sightings once considered unusual can now be matched against precise orbital information, allowing a stronger level of confidence. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

Aircraft Misidentifications

The database contains multiple B-classified reports ultimately attributed to aircraft. In such cases, flight activity, witness descriptions and viewing conditions may strongly support the explanation, but the available evidence may not allow investigators to prove beyond doubt that a particular aircraft caused the observation. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

A witness might report a stationary light that later appears to move in unusual ways. Investigation may show that an aircraft viewed under specific lighting conditions and relative motion effects provides the best explanation. If the match is persuasive but not conclusive, the case remains B rather than A. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

Lanterns and Atmospheric Phenomena

Other published B cases involve sky lanterns, cloud effects and optical phenomena. These reports often display characteristics consistent with known causes, yet lack the documentary evidence needed for a definitive identification. The result is a probable rather than certain resolution. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

Why the A–B Distinction Matters in Public UFO Catalogues

Many UFO databases simply record whether a case is solved or unsolved. GEIPAN’s approach is more granular. By separating identified cases from probably identified cases, the database reveals the degree of confidence attached to each conclusion. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

This distinction helps readers avoid a common misunderstanding: uncertainty does not automatically imply mystery. A sighting may have a highly plausible explanation even when investigators cannot prove it beyond all doubt. The B category captures exactly that situation. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

For researchers and members of the public using UFO report catalogues, A and B classifications therefore serve as a transparency tool. They show not only what investigators think happened, but also how confident they are in that assessment. Cases in both categories are considered resolved, yet the database preserves the difference between a near-certain identification and a well-supported probability. [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi… [Geipan]WikipediaGEIPANGEIPAN (an acronym in French for Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux Non-identifiés, or Unidentifi…

Amazon book picks

Further Reading

Books and field guides related to How GEIPAN Determines Identified and Probable Cases. Use these as the next step if you want deeper reading beyond the article.

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The UFO Experience

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Directly relevant to identified, probable, and unexplained case categories in structured UFO investigation.

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Gives accessible context for official UFO investigation and why resolved versus unresolved cases matter.

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The Report on Unidentified Flying Objects

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Browse more on Amazon: The UFO Experience UFOs UFOs and Government

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Endnotes

1. Source: geipan.fr
   Link: https://geipan.fr/en/recherche/cas/tab?field_date_value=2020-11-18&field_is_new_value=1&field_is_revisited_value=All&field_type_de_cas_target_id=All&order=title&page=21&sort=asc
   Source snippet

   GeipanRecherche de cas[A750] DE AUMELAS (34) VERS GIGNAC (34) 04.12.2021, 04/12/2021, B; [A86] DE SCEAUX (92) VERS PARIS (75) 01.11.2021...

2. Source: geipan.fr
   Link: https://geipan.fr/en/search/cas?field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=field_date_d_observation&page=%2C32&sort=desc
   Source snippet

   Recherche de casThe Geipan. Mission & Geipan · Its history · Documentation · Events · Actualities; Cases & Testimonials. Case search · St...

3. Source: geipan.fr
   Link: https://geipan.fr/en/search/cas?field_agregation_index_value=&field_date_d_observation_value%5Bmax%5D=&field_date_d_observation_value%5Bmin%5D=&field_date_value=&field_departement_target_id=&field_document_existe_ou_pas_value=All&field_is_new_value=All&field_is_revisited_value=All&field_latitude_value%5Bmax%5D=&field_latitude_value%5Bmin%5D=&field_longitude_value%5Bmax%5D=&field_longitude_value%5Bmin%5D=&field_phenomene_target_id=&field_type_de_cas_target_id=All&order=title&page=%2C290&s=09&sort=desc
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   Recherche de casThe Geipan. Mission & Geipan · Its history · Documentation · Events · Actualities; Cases & Testimonials. Case search · St...

4. Source: youtube.com
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   The UFO Office • FRANCE 24...

5. Source: cnes-geipan.fr
   Link: https://www.cnes-geipan.fr/en/node/412

6. Source: cnes-geipan.fr
   Link: https://www.cnes-geipan.fr/en/node/58787
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   GeipanClassificationA more detailed classification (A/B/C/D1/D2) has been used by the GEIPAN. It is based on 2 main criteria: the weirdne...

7. Source: cnes-geipan.fr
   Title: methodologie classification geipan
   Link: https://www.cnes-geipan.fr/en/actualites/methodologie-classification-geipan
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   GeipanLa méthodologie de classification au GEIPAN26 Feb 2021 — La classification du GEIPAN (A/B/C/D1/D2) s'appuie sur l'évaluation de deu...

8. Source: uapedia.ai
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   GEIPAN: France's Official UAP UnitC – Unidentified / not workable (insufficient data to test hypotheses). D – Unidentified after investig...

9. Source: cnes-geipan.fr
   Link: https://www.cnes-geipan.fr/en/node/58788
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   MethodologyClassification categories: Classification A: Phenomenon perfectly identified after investigation. Classification B: Phenomenon...

10. Source: cnes-geipan.fr
    Link: https://www.cnes-geipan.fr/en/glossaire
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    GeipanLe glossaire du GeipanCLASSIFICATION DES CAS. La classification d'un cas nécessite l'évaluation, d'une part, de son degré de consis...

11. Source: cnes-geipan.fr
    Title: evolution classification des cas
    Link: https://www.cnes-geipan.fr/en/actualites/evolution-classification-des-cas
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    GeipanEvolution de la CLASSIFICATION DES CAS10 Dec 2008 — Depuis l'origine, les OBSERVATION de PAN analysés par le GEPAN et le SEPRA sont...

12. Source: Wikipedia
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Additional References

1. Source: researchgate.net
   Link: https://www.researchgate.net/publication/376891986_A_global_picture_of_unidentified_anomalous_phenomena_Towards_a_cross-cultural_understanding_of_a_potentially_universal_issue
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   (PDF) A global picture of unidentified anomalous phenomenaOver recent years, the issue of unidentified anomalous phenomena (UAP) has incr...

2. Source: researchgate.net
   Link: https://www.researchgate.net/publication/369507030_GEIPAN_classification_with_text_mining_and_machine_learning
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   ly explore and classify the content of massive data from databases and from texts.Read more...

3. Source: ufomagazines.com
   Title: ufology news kalytyuk ufology news no 17 july august 2013
   Link: https://www.ufomagazines.com/ufology-news-kalytyuk-ufology-news-no-17-july-august-2013/
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   НОВОСТИ УФОЛОГИИ — Ufology News (Kalytyuk)9 Aug 2013 — GEIPAN uses an ABCD classification system: A for easily identified phenomena, B fo...

   Published: august 2013

4. Source: scribd.com
   Link: https://www.scribd.com/document/316858564/Unidentified-Flying-Object
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   It describes how the term was coined by the US Air Force to...Read more...

5. Source: reddit.com
   Link: https://www.reddit.com/r/UFOs/comments/1l3mw3x/pentagons_aaro_director_jon_kosloski_just_told/
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   "trol." - Leslie Kean, 2010, page 120: [https://archive.org..."](https://archive.org...")...

6. Source: cnes-geipan.fr
   Link: https://www.cnes-geipan.fr/en/node/58791
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   the CNES (French Space Agency). · It also...Read more...

7. Source: cnes-geipan.fr
   Title: 2015 09 01 Spatial Point Pattern Analysis of the Unidentified
   Link: https://www.cnes-geipan.fr/sites/default/files/2015-09-01_Spatial_Point_Pattern_Analysis_of_the_Unidentified.pdf
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   A/B/C/D, forming a kind of scale, which goes from perfectly known and determined...Read more...

8. Source: Wikipedia
   Title: Unidentified flying object
   Link: https://en.wikipedia.org/wiki/Unidentified_flying_object
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   Unidentified flying objectAn unidentified flying object (UFO) is an object or phenomenon seen in the sky but not yet identified or exp...

9. Source: jhmovie.fandom.com
   Title: Unidentified flying object
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   flying object | JH Wiki Collection Wiki - Fandom↑ GEIPAN: Le GEIPAN. Groupe d'Études et d'Informations sur les Phénomènes Aérospatiaux No...

10. Source: ultimatepopculture.fandom.com
    Title: Unidentified flying object
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    flying object | Ultimate Pop Culture Wiki - FandomUnidentified flying object (UFO) is the popular term for any aerial phenomenon that can...