GEPAN Technical Notes
GEPAN's formal scientific output: peer-reviewed internal papers written by CNES scientists who applied astrophysics, statistical analysis, and engineering methodology to the UFO data. All in French, spanning two decades of continuous research.
The Programme
GEPAN (Groupe d'Etudes des Phénomènes Aérospatiaux Non-identifiés) sat inside CNES, the French space agency, from 1977 onwards. Claude Poher founded the programme and established the methodological standards these technical notes embody. Not military intelligence. Not a classified black programme. A civilian space agency, the same organisation that launched Ariane rockets, housed its UFO researchers alongside satellite engineers and atmospheric scientists.
The Notes Techniques read like academic papers because that is what they are. Methodology sections, data tables, statistical tests, formal conclusions. The Louange studies, a subset of the series, went further and explored automated detection systems for anomalous aerial phenomena. These were scientists writing for other scientists, inside an institution that expected that standard.
The A/B/C/D classification system came out of these papers. Category A: fully explained. Category D: reliable witnesses, physical evidence, no conventional explanation. GEIPAN still uses this framework. It solved a practical problem: with limited staff and resources, the programme needed a way to identify which cases warranted full investigation and which could be filed. The system gave them that triage capability, and it worked well enough that nobody has replaced it in nearly fifty years.
Scientific Method
The collection spans statistical analyses of thousands of reports, classification methodology, detection system proposals, and field investigation protocols. The scientists who wrote these papers applied the same analytical standards they used on satellite telemetry and atmospheric data. Same tools. Same rigour. Different subject.
All documents are in French, produced between 1977 and 1995 during the programme's most active research period. They form the scientific backbone of what France built, and what GEIPAN still operates on today.
GEIPAN still maintains a public case database where French citizens and military personnel can file reports and browse cases classified using the A/B/C/D system developed in these papers. The Valensole encounter of 1965 is a Category D case under the classification system developed in these technical notes. French sighting data from across the archive is on the France sightings page.
Document Inventory
| Category | Description | Documents | Date Range |
|---|---|---|---|
| Notes Techniques | Statistical analysis and case classification methodology | 13 | 1977 to 1995 |
| Louange Studies | Detection system research (within Notes Techniques) | Subset | 1980s |
| Investigation Protocols | Standardised field investigation methodology | Subset | 1977 to 1990s |
External Links
GEIPAN Public Case Database (CNES)Francois Louange, working within the GEPAN programme, developed image analysis techniques for evaluating UFO photographs and video. The work addressed a persistent problem: most UFO photographic evidence arrived without provenance controls, making it difficult to distinguish genuine anomalies from conventional objects, double exposures, or deliberate fabrications. Louange's methodology applied optical physics and spatial frequency analysis to identify inconsistencies in lighting, focus, and object geometry. The resulting protocols were later cited by other national investigation programmes and informed how GEIPAN continues to assess photographic and video evidence today.
The field cases that generated much of the photographic evidence these techniques were tested against are in the Field Investigations collection. The statistical and classification work by GEPAN's founding director is in the Claude Poher Studies collection.
