GEIPAN — Phénomènes Aérospatiaux Non identifiés
France's Centre National d'Études Spatiales (CNES) has continuously operated a public UAP study programme since 1 May 1977, when the Groupe d'Étude des Phénomènes Aérospatiaux Non identifiés (GEPAN) was created inside CNES by then-director Yves Sillard. Renamed SEPRA in 1988 and GEIPAN in 2005, the unit is the world's longest continuously operating government UAP investigation programme. Its 3,343 published cases are catalogued by witness location, observation type, and the four-tier PAN classification.
Mission (verbatim, CNES governing decree)
"GEIPAN est chargé de collecter les témoignages d'observation de phénomènes aérospatiaux non identifiés, d'enquêter et d'analyser ces témoignages, et de mettre à la disposition du public les résultats de ses travaux."
In English: "GEIPAN is responsible for collecting UAP observation reports, investigating and analysing them, and making the results of its work available to the public."
PAN classification
PAN A — phénomène identifié (identified — astronomical, aeronautical, atmospheric).
PAN B — phénomène probablement identifié (probably identified).
PAN C — données insuffisantes (insufficient data).
PAN D — phénomène non identifié (unidentified after exhaustive investigation). Sub-divided into D1 (without physical effects) and D2 (with physical effects).
As of the most recent publicly-released breakdown, PAN D cases represent approximately 3.4% of the corpus.
Method
GEIPAN takes reports from civilian witnesses via online form, mail, or phone. Investigators include retired CNES engineers and trained civilian volunteers. Each report passes through: (1) witness interview, (2) site survey if applicable, (3) corroboration against aviation records, satellite passes, meteorological data, (4) classification, (5) publication on the public case database.
Why this matters globally
GEIPAN is uniquely civilian and transparent: every case file (anonymised) is published, classification methodology is documented, and methodology updates are released as PDF whitepapers. AARO's modern multi-sensor framework cites GEIPAN as a structural precedent.