Documents / Official release
This is a 2023 draft research paper by Richard M. Medina and Simon Brewer of the University of Utah and Sean M. Kirkpatrick of the Department of Defense, prepared for journal submission and released in full by AARO in 2025. It analyzes 98,724 NUFORC public sighting reports from 2001 to 2020 by county with a Bayesian model. It finds that more light pollution and tree canopy mean fewer sightings, while more air traffic and military area mean more. Cloud cover showed no relationship.
025 were given, but were still locatable, when spelling errors in the city field were corrected. For those, coordinates were added using online Microsoft services to construct a more complete dataset. The final resulting mappable dataset includes 121,949 points (locatable in the United States), which is 99.16% of the total extraction. For simplicity and interpretation, we focus on the conterminous U.S. from 2001 to 2020, which reduces the number of reported sightings to 98,724. For the analysis we use the total number of sightings per county across this time period to allow us to focus on the spatial patterns. Our temporal range is selected such that entries are assumed to be relatively recent events and not generated from memories decades ago. Internet access to report a sighting would be more feasible beginning about 2000, and is likely responsible for the increase in sighting reports over time. A timeline of reported sightings for the study period is provided in Figure 1, with a marked peak in sightings between 2012 and 2014, followed by a sharp drop between 2015 and 2018. Figure 1 Timeline of NUFORC Reported Sightings from 2001-2020 Figure 2 provides a visualization of the reported sighting spatial distribution for the conterminous U.S. Our preliminary analyses included Alaska and Hawaii; however, the tree canopy dataset did not cover the entirety of Alaska, rather it only included a coastal region. Because of this, we decided to limit the study to the conterminous U.S. The sighting point dataset was aggregated up to the county level for analysis. We selected county, rather than a city resolution for spatial continuity across the conterminous U.S., which helps with interpreting the results. Also, since these events are relatively rare, counties provide large enough areas for a meaningful aggregation of points. For our exploratory analysis, the NUFORC data were standardized by population, such that they are reported as sightings per 10,000 people.Page determined to be Unclassified Reviewed by Chief of Staff, AARO IAW FY24 NDAA, Section 1841 (a)(1)(C) Date: 02/06/2025
Official release, from the nara collection. The PDF is mirrored here; the original link is above. 16 pages are in the text index: search them above, or from the library's search.