Within Infrared
Why Heat Alone Does Not Identify a UAP
A heat signature can prove something crossed the sky, but it often cannot reveal distance, size or identity on its own.
On this page
- What LWIR cameras actually record
- Why distance and size remain unresolved
- How extra sensors reduce thermal ambiguity
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Introduction
A thermal track can demonstrate that an infrared sensor detected a real source of radiation moving across the sky, but it rarely identifies what produced that radiation on its own. This distinction is central to automated instrumented UAP detection. Long-wave infrared (LWIR) cameras are excellent at detecting heat contrast in darkness, yet a single thermal recording normally lacks the independent measurements needed to determine an object’s true distance, physical size, speed or identity. As a result, an apparently striking infrared video may still represent a distant aircraft, a nearby bird, an insect close to the lens, an atmospheric effect or another ordinary object whose geometry cannot be reconstructed from thermal imagery alone. NASA’s independent UAP study reached a similar conclusion at the programme level: without calibrated sensors, complete metadata and multiple independent measurements, even genuine observations often remain scientifically ambiguous. [NASA Science]science.nasa.govNASA ScienceIndependent Study Team ReportIndeed, several apparent UAP have been demonstrated to be sensor artifacts once appropriate cali…
What LWIR cameras actually record
An LWIR camera does not directly measure an object’s size, shape or identity. It measures infrared radiation reaching the detector, which is then converted into image intensity and, in calibrated systems, an estimate of apparent temperature.
Several factors complicate this measurement.
- Emissivity: Different materials emit infrared radiation with different efficiencies. Two objects at the same physical temperature may appear different simply because one emits thermal radiation more effectively than the other.
- Reflected infrared radiation: Some surfaces reflect infrared energy from their surroundings, making the apparent temperature differ from the object’s actual temperature.
- Atmospheric transmission: Water vapour, humidity and other atmospheric effects absorb and scatter infrared radiation before it reaches the sensor.
- Camera calibration: Accurate temperature estimation depends on calibration against known reference sources and knowledge of detector characteristics. [FLIR+2FLIR Support]flir.comHow Does Emissivity Affect Thermal Imaging?How Does Emissivity Affect Thermal Imaging?November 1, 2021 — 1 Nov 2021 — Emissivity is a measure of how efficiently an object radia…
For scientific sky surveys this distinction matters. A bright thermal target is not necessarily hotter than a dim one, nor does greater brightness imply a larger object. The recorded signal is the combined result of the object’s thermal properties, viewing geometry, atmosphere and instrument response.
The Galileo Project’s Dalek system reflects this challenge. Rather than assuming factory output represents true temperatures, its researchers performed their own radiometric calibration using blackbody reference targets so that raw detector values could be interpreted more consistently. Even with that effort, calibration is only one step towards identifying an airborne object. [MDPI]mdpi.comSensors 2025, This paper describes the commissioning process and results. The 16-bit data can be used for thermal radiometry…
Why distance and size remain unresolved
The largest source of ambiguity is geometric rather than thermal.
A single all-sky infrared camera records angular position on the sky. Without an independent range measurement, there is no direct way to determine how far away the object is.
That creates several unavoidable ambiguities.
Small and nearby versus large and distant
A bird crossing a few hundred metres away can occupy the same number of pixels as a large aircraft tens of kilometres distant. The thermal image alone cannot distinguish between these possibilities because both subtend the same apparent angle.
Speed depends on unknown distance
The apparent angular motion of an object across the sky does not uniquely determine its physical velocity. An object moving rapidly nearby can produce the same angular track as a slower object much farther away.
Pixel size limits interpretation
Many airborne targets occupy only a handful of detector pixels. Once a target becomes effectively unresolved, changes in brightness or shape often reflect the optics and detector response more than the object’s actual structure. Studies of thermal imaging performance consistently show that detection range, recognition range and identification range are fundamentally different capabilities. A system may detect that something exists long before it can reliably classify what it is. [PMC]pmc.ncbi.nlm.nih.govThermal Imager Range: Predictions, Expectations, and Realityby D Perić · 2019 · Cited by 98 — Imaging system range defines the maximal…
This is why an isolated thermal video often appears more informative than it really is. Human observers naturally interpret a bright moving spot as representing a solid object with known dimensions, whereas the camera has only measured incoming infrared radiation from one viewing direction.
Why convincing-looking thermal footage can still mislead
Thermal imagery often carries an impression of objectivity because it appears to reveal “hidden” heat invisible to ordinary cameras. In practice, several mechanisms can make thermal footage appear more decisive than the underlying measurements justify.
A changing viewing angle can alter the apparent thermal signature of an aircraft as engines, fuselage and exhaust become more or less visible. Atmospheric turbulence can distort the apparent shape of distant heat sources. Automatic gain control within the camera may continually adjust image contrast, making targets brighten or dim even when their actual thermal emission changes little.
Weather introduces additional uncertainty. Humidity, precipitation and airborne particles reduce infrared transmission, while warm cloud edges or atmospheric gradients can create changing backgrounds that complicate automated detection. Ground-based LWIR systems therefore experience variable performance depending on environmental conditions rather than operating with constant sensitivity. [PMC]pmc.ncbi.nlm.nih.govThermal Imager Range: Predictions, Expectations, and Realityby D Perić · 2019 · Cited by 98 — Imaging system range defines the maximal…
These limitations do not make thermal observations unreliable; they define what information the observations genuinely contain.
How extra sensors reduce thermal ambiguity
The most effective solution is not a better thermal camera but additional, independently calibrated measurements.
When multiple sensors observe the same event simultaneously, several previously unknown quantities become measurable.
- Visible-light cameras provide colour, navigation lights, structural features and reflected-light behaviour that thermal imagery cannot show.
- Multiple separated cameras enable triangulation, allowing range, altitude and true velocity to be estimated.
- Radar supplies independent distance and radial velocity measurements.
- ADS-B aircraft broadcasts can eliminate many ordinary aircraft before a track is treated as anomalous.
- Weather data help identify clouds, atmospheric effects and changing transmission conditions.
- Acoustic or radio sensors may provide further evidence consistent with conventional aircraft or other known sources.
The Galileo Project’s observing architecture follows precisely this philosophy. Its infrared array is designed as one component within a multimodal observatory rather than as a standalone identification system. Early commissioning data illustrate why: although hundreds of thousands of trajectories were detected, a small subset remained ambiguous after automated filtering, demonstrating that ambiguity is an expected outcome rather than evidence of extraordinary objects. [Phys.org]phys.org144 trajectories remained ambiguous, information,An all-sky infrared camera named Dalek continues the…April 9, 2025 — 9 Apr 2025 — Galileo Project proposes an All-Sky Infrared Camera…
NASA’s independent UAP study likewise emphasised that future progress depends on multiple calibrated sensors, complete metadata and systematic data collection rather than reliance on isolated imagery. [NASA Science]science.nasa.govNASA ScienceIndependent Study Team ReportIndeed, several apparent UAP have been demonstrated to be sensor artifacts once appropriate cali…
The practical lesson for automated UAP detectors
Within an automated instrumented observatory, a thermal-only track should be treated as a detection rather than an identification.
Its scientific value lies in confirming that an event occurred, preserving precise timing and geometry, and triggering cross-checks against other instruments. If multiple independent measurements agree, confidence in the reconstructed object increases substantially. If only a single thermal signature exists, the correct conclusion is usually not that the object is extraordinary, but that the available measurements are insufficient to determine what it was.
For this reason, modern scientific UAP detection projects increasingly judge success not by producing dramatic infrared footage, but by reducing ambiguity through calibrated instrumentation, sensor fusion and reproducible measurements. That approach transforms thermal imaging from an apparent endpoint into one component of a broader evidence chain. [MDPI]mdpi.comSensors 2025, This paper describes the commissioning process and results. The 16-bit data can be used for thermal radiometry…
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Endnotes
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Source: science.nasa.gov
Link: https://science.nasa.gov/wp-content/uploads/2023/09/uap-independent-study-team-final-report.pdfSource snippet
NASA ScienceIndependent Study Team ReportIndeed, several apparent UAP have been demonstrated to be sensor artifacts once appropriate cali...
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Source: nasa.gov
Title: update nasa shares uap independent study report names director
Link: https://www.nasa.gov/news-release/update-nasa-shares-uap-independent-study-report-names-director/Source snippet
UPDATE: NASA Shares UAP Independent Study Report14 Sept 2023 — NASA can help the whole-of-government UAP effort through systematic data c...
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Source: flir.com
Title: How Does Emissivity Affect Thermal Imaging?
Link: https://www.flir.com/en-gb/discover/professional-tools/how-does-emissivity-affect-thermal-imaging/Source snippet
How Does Emissivity Affect Thermal Imaging?November 1, 2021 — 1 Nov 2021 — Emissivity is a measure of how efficiently an object radia...
Published: November 1, 2021
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Source: support.flir.com
Link: https://support.flir.com/DSDownload/Assets/T810442-en-US_A4.pdfSource snippet
FLIR SupportReference documentation Thermography13 Aug 2019 — Calibration of a thermal camera is a prerequisite for temperature measureme...
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Source: flir.com
Link: https://www.flir.com/en-gb/discover/rd-science/infrared-camera-accuracy-and-uncertainty-in-plain-language/Source snippet
Infrared Camera Accuracy and Uncertainty in Plain...12 Sept 2023 — Looking at this data, it would be tempting to claim an expected a...
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Source: mdpi.com
Link: https://www.mdpi.com/1424-8220/25/3/783Source snippet
Sensors 2025, This paper describes the commissioning process and results. The 16-bit data can be used for thermal radiometry...
-
Source: pmc.ncbi.nlm.nih.gov
Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC6696215/Source snippet
Thermal Imager Range: Predictions, Expectations, and Realityby D Perić · 2019 · Cited by 98 — Imaging system range defines the maximal...
-
Source: phys.org
Title: 144 trajectories remained ambiguous, information,
Link: https://phys.org/news/2025-04-sky-infrared-camera-dalek-alien.htmlSource snippet
An all-sky infrared camera named Dalek continues the...April 9, 2025 — 9 Apr 2025 — Galileo Project proposes an All-Sky Infrared Camera...
Published: April 9, 2025
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Source: science.nasa.gov
Link: https://science.nasa.gov/uap/Source snippet
nasa.govUAP9 Jun 2022 — The study will focus on identifying available data, how best to collect future data, and how NASA can use that da...
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Source: nasa.gov
Title: to release discuss unidentified anomalous phenomena report
Link: https://www.nasa.gov/news-release/nasa-to-release-discuss-unidentified-anomalous-phenomena-report/Source snippet
NASA to Release, Discuss Unidentified Anomalous...12 Sept 2023 — NASA commissioned the study to examine UAP from a scientific perspectiv...
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Source: flir.custhelp.com
Title: flir cameras temperature measurement formula
Link: https://flir.custhelp.com/app/answers/detail/a_id/3321/~/flir-cameras—temperature-measurement-formulaSource snippet
Cameras - Temperature Measurement Formula6 Dec 2025 — Most FLIR software calculates temperature automatically. Any infrared camera detect...
Additional References
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Source: researchgate.net
Link: https://www.researchgate.net/publication/388466760_Commissioning_an_All-Sky_Infrared_Camera_Array_for_Detection_of_Airborne_ObjectsSource snippet
(PDF) Commissioning an All-Sky Infrared Camera Array for...10 Jan 2025 — The Galileo Project's simultaneous multi-channel recording arch...
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Source: medium.com
Link: https://medium.com/%40omarvferro/seriously-are-all-those-blurry-dots-in-[infrared-camerasSource snippet
Seriously, Are All Those Blurry Dots in Infrared Cameras...NASA UAP Report Analysis: Evaluating Extraterrestrial Evidence, Infrared Sens...
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Source: rev.com
Title: unidentified anomalous phenomena independent study report from nasa transcript
Link: https://www.rev.com/transcripts/unidentified-anomalous-phenomena-independent-study-report-from-nasa-transcriptSource snippet
UAP Independent Study Report from NASA18 Sept 2023 — NASA always takes a scientific approach of systematic data collection that involves...
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Source: youtube.com
Link: https://www.youtube.com/watch?v=YXBsIOGsZE0Source snippet
REPLAY! NASA Unidentified Anomalous Phenomena...NASA defines UAP as observations of events in the sky that cannot be identified as aircr...
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Source: spaceref.com
Title: nasa shares unidentified anomalous phenomena independent study report
Link: https://spaceref.com/newspace-and-tech/nasa-shares-unidentified-anomalous-phenomena-independent-study-report/Source snippet
NASA Shares Unidentified Anomalous Phenomena...14 Sept 2023 — We found that NASA can help the whole-of-government UAP effort through sys...
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Source: salon.com
Title: nasa report finds no evidence that ufos are extraterrestrial partner
Link: https://www.salon.com/2023/09/19/nasa-report-finds-no-evidence-that-ufos-are-extraterrestrial_partner/Source snippet
NASA report finds no evidence that UFOs are extraterrestrial19 Sept 2023 — Analysis of this data is “hampered by poor sensor calibration...
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Source: meritalk.com
Title: nasa urged to take more permanent role in uap research effort
Link: https://www.meritalk.com/articles/nasa-urged-to-take-more-permanent-role-in-uap-research-effort/Source snippet
NASA Urged to Take More Permanent Role in UAP...15 Sept 2023 — The study team found that most UAP data is “hampered by poor sensor calib...
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Source: en.wikisource.org
Link: https://en.wikisource.org/wiki/Page%3AUAP_Independent_Study_Team_-_Final_Report.pdf/5Source snippet
wikisource.orgPage:UAP Independent Study Team - Final Report.pdf/512 Nov 2023 — At present, analysis of UAP data is hampered by poor sens...
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Source: avweb.com
Title: nasa report no aliens but more uap investigations needed
Link: https://avweb.com/aviation-news/nasa-report-no-aliens-but-more-uap-investigations-needed/Source snippet
NASA Report: No Aliens, But More UAP Investigations...15 Sept 2023 — The report said investigations have thus far “been hampered by poor...
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Source: researchgate.net
Link: https://www.researchgate.net/publication/348876089_Spot_size_distance_and_emissivity_errors_in_field_applications_of_infrared_thermographySource snippet
stimates of known, calibrated temperature sources, with similar results...Read more...
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