Research Papers

Research Papers

Dive into the academic and scientific rigor behind UAP studies with a curated list of impactful research papers and publications.


Exploring Unidentified Aerospace Phenomena through Instrumented Field Studies: Historical Insights, Current Challenges, and Future Directions

P. Ailleris

The study of Unidentified Aerospace Phenomena (UAP) requires a shift from a historical, narrative-based approach to a scientific and technology-based study. To conduct unbiased and agnostic research on UAPs, rigorous scientific study is necessary, including the collection of hard data to support credible explanations or scientifically prove the existence of unknown phenomena. Obtaining reliable and valid data requires instrumented observations, including multi-wavelength and multi-mode sensors (e.g., optical, radar, infrared). We present herein an overview of the benefits as well as the strategic and tactical considerations of instrumented field studies, highlighting common limitations and shortcomings with the objective of contributing to the development of future projects. We provide an overview of some past and current UAP military and civilian projects and analyze a timetable of instrumented projects spanning the years 1950-2023, encompassing contributions from both citizen science and professional/academic science. In conclusion, this paper reflects on how UAP field experiments might look going forward. Newer technologies like digital cameras, scientific instruments, computing, big data analytics, artificial intelligence, and satellite imagery are becoming more advanced and cost-effective. This is leading to the growth and progress of technical field studies, complementing local projects with global-scale investigations. Researchers can enhance their chances of success by adopting a more disciplined approach and exploring innovative avenues. Collaboration, transparency, and standardization in data collection and analysis are crucial, while also acknowledging the complex nature of the UAP phenomenon.

Limina: The Journal of UAP Studies

January 31, 2024


Initial Results From the First Field Expedition of UAPx to Study Unidentified Anomalous Phenomena

M. Szydagis, K.H. Knuth, B.W. Kugielsky, C. Levy, J.D. McGowan, M.D. Phelan, and G.P. Voorhis Jr

In July 2021, faculty from the UAlbany Department of Physics participated in a week-long field expedition with the organization UAPx to collect data on UAPs in Avalon, California, located on Catalina Island, and nearby. This paper reviews both the hardware and software techniques which this collaboration employed, and contains a frank discussion of the successes and failures, with a section about how to apply lessons learned to future expeditions. Both observable-light and infrared cameras were deployed, as well as sensors for other (non-EM) emissions. A pixel-subtraction method was augmented with other similarly simple methods to provide initial identification of objects in the sky and/or the sea crossing the cameras' fields of view. The first results will be presented based upon approximately one hour in total of triggered visible/night-vision-mode video and over 600 hours of untriggered (far) IR video recorded, as well as 55 hours of (background) radiation measurements. Following multiple explanatory resolutions of several ambiguities that were potentially anomalous at first, we focus on the primary remaining ambiguity captured at approximately 4am Pacific Time on Friday, July 16: a dark spot in the visible/near-IR camera possibly coincident with ionizing radiation that has thus far resisted a prosaic explanation. We conclude with quantitative suggestions for serious researchers in this still-nascent field of hard-science-based UAP studies, with an ultimate goal of identifying UAPs without confirmation bias toward either mundane or speculative conclusions.

December 1, 2023

Scientific Coalition for UAP Studies

UAP Indications Analysis: 1945-1975 United States Atomic Warfare Complex

L. J. Hancock, I. M. Porrit, and S. Grosvenor

This paper provides an assessment of indicators associated with unidentified anomalous phenomena (UAP) reports near American military and aerospace facilities and ranks the relative likelihood of the following four intention scenarios: 1) general military survey, 2) atomic weapons survey, 3) atomic warfare prevention and 4) military aggression. This study follows on the work presented in UAP Pattern Recognition Study 1945-1975, US Military Atomic Warfare Complex (Hancock et al., 2023a), and is based on the conclusions that intelligent and focused activity was associated with UAP near atomic facilities to a greater degree than near conventional non-atomic military facilities. The data for this indications analysis include both the original 590 UAP reports and the five study sites in Hancock et al., 2023a: 1) atomic materials production, 2) atomic weapons assembly, 3) atomic weapons stockpiles, 4) atomic weapons deployment, and 5) rocket/missile testing and development, plus a further 284 UAP reports that indicated either engaged aircraft, active radar jamming, radio interference in the form of noise on aircraft audio receivers, radar interference / jamming of aircraft receivers, directed radar frequency transmissions mimicking the frequencies used by pilots, coded radar frequency transmissions identification friend or foe; or were observed during missile, rocket, and high-altitude balloon tests, or over military installations. Intention analysis was applied to assess scenarios related to information collection/ survey, deterrent/obstruction of military activities, and aggressive engagement. A list of indicators was created, and four major scenarios were considered for assessment. Results indicated that an atomic weapons survey was the most likely scenario. General military survey was the next likely scenario. Atomic warfare prevention and military aggression appeared as the least likely scenarios, in that order; we found little evidence to support prevention or aggression as primary intentions.

August 14, 2023


Reconstruction of Potential Flight Paths for the January 2015 “Gimbal” UAP

Yannick Peings and Marik von Rennenkampff

The so-called “Gimbal” video is arguably the most recognizable publicly-available footage of unidentified anomalous phenomena (UAP). Recorded in January 2015 off the coast of Jacksonville, Florida, by a U.S. Navy F/A-18F Super Hornet’s AN/ASQ-228 ATFLIR targeting pod, the video shows an infrared-significant object skimming over clouds. Towards the end of the 34-second clip, the object appears to stop and rotate in mid-air. Naval aviators who participated in the event indicate that: (1) The UAP was within 10 nautical miles of the F/A-18F, (2) that, from the perspective of the aircrew’s top-down radar display, it was seen to stop and reverse direction with no radius of turn, and (3) that the UAP was accompanied by a formation of 4-6 other unknown objects. Using data from the ATFLIR video, it is possible to reconstruct potential flight paths for the object as a function of distance. We show that, at the range provided by the aviators, potential flight paths align with eyewitness accounts: The object decelerates from a few hundred knots before rapidly reversing direction in a “vertical U-turn.” Such a maneuver would have been observed on the overhead radar display as an abrupt reversal of direction with no radius of turn. The highly anomalous flight path found at the range provided by the aircrew, along with the remarkable match between the reconstructed flight path, eyewitness recollections, and the object’s rotation, raises intriguing questions about the nature of the object. This is especially the case because, at this distance, no wings or infrared signatures consistent with conventional means of propulsion (e.g., an exhaust plume in the direction of flight) are visible. An alternative hypothesis, which proposes that Gimbal shows infrared “glare” from the exhaust of a conventional jet aircraft viewed approximately tail-on 30 nautical miles from the F/A-18F, is also discussed. According to this theory, the rotation observed in the video is an artifact of the ATFLIR targeting pod. Our goal is to provide an overview of analyses of the Gimbal encounter conducted by private citizens. We encourage aeronautics/aerospace experts to provide feedback so that a better understanding of the Gimbal UAP may be achieved.

Aerospace Research Central

June 8, 2023

Galileo Project

The Scientific Investigation of Unidentified Aerial Phenomena (UAP) Using Multimodal Ground-Based Observatories

Wesley Andrés Watters, Abraham Loeb, Frank Laukien, Richard Cloete, Alex Delacroix, Sergei Dobroshinsky, Benjamin Horvath, Ezra Kelderman, Sarah Little, Eric Masson, Andrew Mead, Mitch Randall, Forrest Schultz, Matthew Szenher, Foteini Vervelidou, Abigail White, Angelique Ahlström, Carol Cleland, Spencer Dockal, Natasha Donahue, Mark Elowitz, Carson Ezell, Alex Gersznowicz, Nicholas Gold, Michael G. Hercz, Eric Keto, Kevin H. Knuth, Anthony Lux, Gary J. Melnick, Amaya Moro-Martín, Javier Martin-Torres, Daniel Llusa Ribes, Paul Sail, Massimo Teodorani, John Joseph Tedesco, Gerald Thomas Tedesco, Michelle Tu, and Maria-Paz Zorzano

Unidentified Aerial Phenomena (UAP) have resisted explanation and have received little formal scientific attention for 75 years. A primary objective of the Galileo Project is to build an integrated software and instrumentation system designed to conduct a multimodal census of aerial phenomena and to recognize anomalies. Here we present key motivations for the study of UAP and address historical objections to this research. We describe an approach for highlighting outlier events in the high-dimensional parameter space of our census measurements. We provide a detailed roadmap for deciding measurement requirements, as well as a science traceability matrix (STM) for connecting sought-after physical parameters to observables and instrument requirements. We also discuss potential strategies for deciding where to locate instruments for development, testing, and final deployment. Our instrument package is multimodal and multispectral, consisting of (1) wide-field cameras in multiple bands for targeting and tracking of aerial objects and deriving their positions and kinematics using triangulation; (2) narrow-field instruments including cameras for characterizing morphology, spectra, polarimetry, and photometry; (3) passive multistatic arrays of antennas and receivers for radar-derived range and kinematics; (4) radio spectrum analyzers to measure radio and microwave emissions; (5) microphones for sampling acoustic emissions in the infrasonic through ultrasonic frequency bands; and (6) environmental sensors for characterizing ambient conditions (temperature, pressure, humidity, and wind velocity), as well as quasistatic electric and magnetic fields, and energetic particles. The use of multispectral instruments and multiple sensor modalities will help to ensure that artifacts are recognized and that true detections are corroborated and verifiable. Data processing pipelines are being developed that apply state-of-the-art techniques for multi-sensor data fusion, hypothesis tracking, semi-supervised classification, and outlier detection.

Journal of Astronomical Instrumentation

May 13, 2023

Galileo Project

Multi-Band Acoustic Monitoring of Aerial Signatures

Andrew Mead, Sarah Little, Paul Sail, Michelle Tu, Wesley Andrés Watters, Abigail White, and Richard Cloete

The acoustic monitoring, omni-directional system (AMOS) in the Galileo Project is a passive, multi-band, field microphone suite designed to aid in the detection and characterization of aerial phenomena. Acoustic monitoring augments the Project’s electromagnetic sensors suite by providing a relatively independent physical signal modality with which to validate the identification of known phenomena and to more fully characterize detected objects. The AMOS system spans infrasonic frequencies down to 0.05Hz, all of audible, and ultrasonic frequencies up to 190kHz. It uses three distinct systems with overlapping bandwidths: infrasonic (0.05Hz – 20Hz), audible (10Hz – 20kHz), and ultrasonic (16kHz – 190kHz). The sensors and their capture devices allow AMOS to monitor and characterize the tremendous range of sounds produced by natural and human-made aerial phenomena, and to encompass possible acoustic characteristics of novel sources. Sound signals from aerial objects can be captured and classified with a single microphone under the following conditions: the sound reaches the sensor; the sound level is above ambient noise; and the signal has not been excessively distorted by the transmission path. A preliminary examination of the signal and noise environment required for the detection and characterization of aerial objects, based on theoretical and empirical equations for sound attenuation in air, finds that moderately loud audible sources (100dB) at 1km are detectable, especially for frequencies below 1kHz and in quiet, rural environments. Infrasonic sources are detectable at much longer distances and ultrasonic at much shorter distances. Preliminary aircraft recordings collected using the single, omni-directional audible microphone are presented, along with basic spectral analysis. Such data will be used in conjunction with flight transponder data to develop algorithms and corresponding software for quickly identifying known aircraft and characterizing the sound transmission path. Future work will include multi-sensor audible and infrasonic arrays for sound localization; analysis of larger and more diverse data sets; and exploration of machine learning and artificial intelligence integration for the detection and identification of many more types of known phenomena in all three frequency bands.

Journal of Astronomical Instrumentation

May 5, 2023

Galileo Project

Physical Considerations for an Intercept Mission to a 1I/’Oumuamua-Like Interstellar Object

Amir Siraj, Abraham Loeb, Amaya Moro-Martín, Mark Elowitz, Abigail White, Wesley A. Watters, Gary J. Melnick, Richard Cloete, Jonathan Grindlay, and Frank Laukien

In this paper, we review some of the extant literature on the study of interstellar objects (ISOs). With the forthcoming Vera C. Rubin Telescope and Legacy Survey of Space and Time (LSST), we find that 0.38−84 ‘Oumuamua-like interstellar objects are expected to be detected in the next 10 years, with 95% confidence. The feasibility of a rendezvous trajectory has been demonstrated in previous work. In this paper, we investigate the requirements for a rendezvous mission with the primary objective of producing a resolved image of an interstellar object. We outline the rendezvous distances necessary as a function of resolution elements and object size. We expand upon current population synthesis models to account for the size dependency on the detection rates for reachable interstellar objects. We assess the trade-off between object diameter and occurrence rate, and conclude that objects with the size range between a third of the size and the size of ‘Oumuamua will be optimal targets for an imaging rendezvous. We also discuss expectations for surface properties and spectral features of interstellar objects, as well as the benefits of various spacecraft storage locations.

Journal of Astronomical Instrumentation

April 22, 2023

Galileo Project

SkyWatch: A Passive Multistatic Radar Network for the Measurement of Object Position and Velocity

Mitch Randall, Alex Delacroix, Carson Ezell, Ezra Kelderman, Sarah Little, Abraham Loeb, Eric Masson, Wesley Andrés Watters, Richard Cloete, and Abigail White

Quantitative three-dimensional (3D) position and velocity estimates obtained by passive radar will assist the Galileo Project in the detection and classification of aerial objects by providing critical measurements of range, location, and kinematics. These parameters will be combined with those derived from the Project’s suite of electromagnetic sensors and used to separate known aerial objects from those exhibiting anomalous kinematics. SkyWatch, a passive multistatic radar system based on commercial broadcast FM radio transmitters of opportunity, is a network of receivers spaced at geographical scales that enables estimation of the 3D position and velocity time series of objects at altitudes up to 80km, horizontal distances up to 150km, and at velocities to ±2km/s (±6 Mach). The receivers are designed to collect useful data in a variety of environments varying by terrain, transmitter power, relative transmitter distance, adjacent channel strength, etc. In some cases, the direct signal from the transmitter may be large enough to be used as the reference with which the echoes are correlated. In other cases, the direct signal may be weak or absent, in which case a reference is communicated to the receiver from another network node via the internet for echo correlation. Various techniques are discussed specific to the two modes of operation and a hybrid mode. Delay and Doppler data are sent via internet to a central server where triangulation is used to deduce time series of 3D positions and velocities. A multiple receiver (multistatic) radar experiment is undergoing Phase 1 testing, with several receivers placed at various distances around the Harvard–Smithsonian Center for Astrophysics (CfA), to validate full 3D position and velocity recovery. The experimental multistatic system intermittently records raw data for later processing to aid development. The results of the multistatic experiment will inform the design of a compact, economical receiver intended for deployment in a large-scale, mass-deployed mesh network. Such a network would greatly increase the probability of detecting and recording the movements of aerial objects with anomalous kinematics suggestive of Unidentified Aerial Phenomena (UAP).

Journal of Astronomical Instrumentation

April 18, 2023

Scientific Coalition for UAP Studies

UAP Pattern Recognition Study 1945-1975 US Military Atomic Warfare Complex

L. J. Hancock, I. M. Porritt, S. Grosvenor, L. Cates, and I. Okafor

This paper provides a view of the pattern of reported Unidentified Aerospace Phenomena (UAP) in the United States associated with the military atomic weapons complex between 1945 and 1975. A set of 590 comprehensively documented UAP reports from this period were collected from select sources, including Project Blue Book. These were analyzed graphically for spatial and temporal differences between the number of incidents reported at sites within the atomic warfare complex, and control sites. Initial study site classes were: 1) radioactive materials production plants; 2) atomic weapons assembly facilities, and 3) atomic weapons stockpile sites. Control sites classes were 1) civilian population centers and 2) high-security, non-atomic weapons military bases. Elevated UAP activity was found at all three atomic site classes and was most noticeable in the earliest facility in each class. UAP activity began during the construction phase for some sites and escalated when the site became operational. Elevated activity at study sites occurred in a "window" between 1948-1951, continued through the national spike in UAP reporting in 1952, then dramatically decreased, never to repeat the "window" levels during the remainder of the study period. The second phase of the study compared additional atomic weapons deployment sites vs: 4) additional non-atomic military sites, and 5) major American rocket/missile and aerospace test and development facilities. Moderately elevated UAP activity was associated with bases where atomic weapons were operationally deployed (Air Force and Navy). Distinctive patterns of UAP activity were noted in conjunction with the deployment of Inter-Continental Ballistic Missiles (ICBM), and other individual and distinctive patterns of UAP incident reports were noted for different types of atomic weapons complex sites over the full period of this study.

March 21, 2023

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This website ( is an independent community-driven platform and is not affiliated with, endorsed by, or representative of any official government entity, including the UAP Caucus within the House of Representatives, or any other official body. The views, frameworks, and content expressed on this site are those of the contributors and do not reflect the official stance or endorsement of any governmental organization.

This website ( is an independent community-driven platform and is not affiliated with, endorsed by, or representative of any official government entity, including the UAP Caucus within the House of Representatives, or any other official body. The views, frameworks, and content expressed on this site are those of the contributors and do not reflect the official stance or endorsement of any governmental organization.