Within Calibration
Why matched planes should not just disappear
ADS-B can identify ordinary aircraft, but its greater value is preserving known targets for detector testing and calibration.
On this page
- The weak filter only approach
- How labelled aircraft improve detector audits
- Why retained matches help catch sensor drift
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Introduction
In an automated instrumented UFO or UAP detector, an ADS-B match should not be viewed merely as an aircraft that has been successfully filtered out. Its greater value is that it transforms a detected object into a labelled, independently verified target. Every matched aircraft provides a real-world test case with known position, altitude, speed and trajectory against which the detector can measure its own performance. This distinction matters because the central challenge in anomaly detection is not simply removing ordinary objects; it is proving that the sensor system understands ordinary objects well enough to recognise something genuinely unusual. NASA’s UAP study emphasised that poor calibration, missing metadata and a lack of baseline observations are major obstacles to reliable analysis. ADS-B-equipped aircraft help address exactly those problems. [NASA]nasa.govupdate nasa shares uap independent study report names directorUPDATE: NASA Shares UAP Independent Study Report14 Sept 2023 — NASA can help the whole-of-government UAP effort through systematic da…
Within the broader role of ordinary aircraft as calibration targets, ADS-B matches create a continuous stream of labelled observations. Instead of disappearing from the dataset as discarded false positives, they become evidence that the instrument is functioning correctly—or evidence that it is drifting away from correct operation.
The Weak Filter-Only Approach
A detector designed around a simple filtering philosophy treats an ADS-B correlation as the end of the story. An object is detected, matched to a flight track, labelled “aircraft”, and removed from further consideration.
This approach reduces alert volume, but it wastes information. Once the match is discarded, the system loses an opportunity to answer important questions:
- Did the camera place the aircraft in the correct location?
- Did the tracking software estimate motion accurately?
- Was the object detected at the expected range?
- Did weather conditions reduce detection probability?
- Has the sensor’s pointing accuracy changed since the previous week?
A detector can therefore appear successful because it rejects aircraft, while simultaneously becoming less accurate over time. The filtering task may continue to work even as calibration slowly degrades.
This distinction is especially important for UAP research because a system that cannot reliably characterise known aircraft cannot credibly characterise unknown objects. NASA’s review repeatedly stressed that reliable anomaly analysis depends on calibrated sensors, complete metadata and a strong baseline understanding of normal observations. [NASA+2Space]nasa.govupdate nasa shares uap independent study report names directorUPDATE: NASA Shares UAP Independent Study Report14 Sept 2023 — NASA can help the whole-of-government UAP effort through systematic da…
How Labelled Aircraft Improve Detector Audits
ADS-B provides something unusually valuable in observational science: ground truth. The aircraft broadcasts information independently of the observing instrument. The detector therefore receives an external reference against which its own measurements can be checked.
Recent work from the Galileo Project demonstrates how this idea extends far beyond filtering. During commissioning of its all-sky infrared observatory, ADS-B-equipped aircraft were used not only for identification but for camera calibration, performance evaluation and construction of operational baselines. Researchers used ADS-B data to establish performance envelopes, assess detection efficiency under different weather conditions, and evaluate tracking algorithms against known targets. Over a five-month commissioning period, roughly half a million aerial trajectories were reconstructed and analysed using these methods. [MDPI+2arXiv]mdpi.comCommissioning an All-Sky Infrared Camera Array for…by L Domine · 2025 · Cited by 11 — This paper describes the innovative commissi…
The result is an audit trail that a filter-only system lacks.
Aircraft Become Performance Benchmarks
Once aircraft observations are retained rather than discarded, each one becomes a benchmark event.
A detector can measure:
- Detection rate: How many visible aircraft are successfully detected?
- Tracking quality: How closely does the reconstructed path follow the known trajectory?
- Classification accuracy: How often are aircraft correctly recognised?
- Environmental sensitivity: How does performance change with haze, cloud, rain or distance?
- Sensor agreement: Do optical, infrared, acoustic and radio sensors tell a consistent story?
This turns ordinary air traffic into a continuous quality-control programme. Every passing aircraft contributes evidence about instrument performance.
Known Targets Enable Quantified Error Bars
One of the persistent problems in anomaly claims is uncertainty. A track may look unusual, but without calibration there is often no way to determine whether the anomaly belongs to the object or the sensor.
Labelled aircraft allow error distributions to be measured directly. If hundreds or thousands of aircraft consistently show a certain pointing error, timing offset or tracking uncertainty, those values can be incorporated into later anomaly assessments. The result is a detector that reports not only what it saw but how confidently it measured it. [MDPI+2arXiv]mdpi.comCommissioning an All-Sky Infrared Camera Array for…by L Domine · 2025 · Cited by 11 — This paper describes the innovative commissi…
Why Retained Matches Help Catch Sensor Drift
A more subtle benefit of ADS-B matches is long-term monitoring of instrument health.
Outdoor sky-monitoring systems experience gradual change. Cameras shift slightly. Mounts settle. Temperatures fluctuate. Optics age. Software updates alter processing behaviour. None of these changes necessarily produces an obvious failure.
If aircraft matches are preserved, they provide a historical reference set that can reveal these slow degradations.
For example, suppose a camera originally placed ADS-B aircraft within one degree of their expected position. Six months later the average error increases to three degrees. Without retained aircraft data, that change may go unnoticed. With retained matches, the trend becomes measurable.
The Galileo Project’s commissioning work illustrates this principle directly. Because aircraft tracks were maintained as part of the calibration and validation dataset, researchers could establish operational performance envelopes and evaluate system behaviour across different observing conditions rather than merely excluding known aircraft from analysis. [MDPI+2arXiv]mdpi.comCommissioning an All-Sky Infrared Camera Array for…by L Domine · 2025 · Cited by 11 — This paper describes the innovative commissi…
Detecting Software Drift
Hardware is not the only concern.
Modern automated detectors increasingly rely on machine-learning classifiers and adaptive processing pipelines. Software updates can alter detection behaviour without changing the physical sensor.
Retained ADS-B matches provide a stable reference population against which software revisions can be tested. If an update suddenly reduces aircraft detection rates or increases positional errors, the problem can be identified before it contaminates anomaly statistics.
In effect, the aircraft population serves as a permanent regression-testing dataset generated by the sky itself.
The Risk of Throwing Away the Best Calibration Data
A paradox emerges in automated UAP detection. The objects that researchers most want to study are rare, but the objects they most need for calibration are abundant.
Aircraft provide repeated observations at different ranges, altitudes, speeds, illumination conditions and weather states. They appear daily, often in large numbers, and many carry independent positional information through ADS-B. Few other aerial targets offer such a rich combination of observability and verification. [MDPI+2Galileo Project]mdpi.comCommissioning an All-Sky Infrared Camera Array for…by L Domine · 2025 · Cited by 11 — This paper describes the innovative commissi…
Discarding ADS-B matches immediately after identification therefore removes some of the most scientifically valuable observations available to the system. A detector that retains them gains a continuously refreshed reference library against which future anomalies can be tested.
For an automated instrumented UFO detector, the important question is not merely whether an aircraft can be filtered out. The more important question is whether that aircraft can be used to prove that the detector is working correctly. ADS-B matches are valuable precisely because they answer both questions at the same time.
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Endnotes
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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 da...
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Source: space.com
Title: sensor metadata, and the lack of [baseline data]({{ ‘baseline-data/’ | relative_url }}),” the report states.Read more
Link: https://www.space.com/nasa-ufo-uap-study-team-first-results-revealedSource snippet
NASA UFO report finds no evidence of 'extraterrestrial...14 Sept 2023 — "At present, analysis of UAP data is hampered by poor senso...
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Source: mdpi.com
Link: https://www.mdpi.com/1424-8220/25/3/783Source snippet
Commissioning an All-Sky Infrared Camera Array for...by L Domine · 2025 · Cited by 11 — This paper describes the innovative commissi...
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Source: arxiv.org
Link: https://arxiv.org/abs/2411.07956Source snippet
Commissioning An All-Sky Infrared Camera Array for...by L Dominé · 2024 · Cited by 11 — Their calibration includes a novel extrinsic cal...
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Source: science.nasa.gov
Link: https://science.nasa.gov/uap/Source snippet
nasa.govUAP9 Jun 2022 — A study team to examine unidentified anomalous phenomena (UAPs) – that is, observations of events in the sky that...
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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 defines UAP as observations of events in the sky that cannot be id...
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Source: arxiv.org
Link: https://arxiv.org/html/2411.07956v1Source snippet
1 Introduction12 Nov 2024 — In addition to performing intrinsic and thermal calibrations, we implement a novel extrinsic calibration meth...
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Source: thedebrief.org
Link: https://thedebrief.org/galileo-project-releases-commissioning-data-on-half-a-million-aerial-objects-are-any-of-them-uap/Source snippet
Using machine...Read more...
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Source: galileo.hsites.harvard.edu
Link: https://galileo.hsites.harvard.edu/FAQSource snippet
Galileo ProjectFrequently Asked Questions | The Galileo Project26 Jan 2022 — The Galileo Project will utilize AI to filter observations o...
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Source: researchgate.net
Title: 317599939 Large Scale ADS B Data and Signal Quality Analysis
Link: https://www.researchgate.net/publication/317599939_Large-Scale_ADS-B_Data_and_Signal_Quality_AnalysisSource snippet
Galileo Project is designing, building, and commissioning a...
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Source: Wikipedia
Title: The Galileo Project
Link: https://en.wikipedia.org/wiki/The_Galileo_ProjectSource snippet
The Galileo ProjectThe Galileo Project is an international scientific research project to search for extraterrestrial intelligence or...
Additional References
-
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 — Galileo Project is designing, building, and commissioning a mul...
-
Source: avi-loeb.medium.com
Link: https://avi-loeb.medium.com/commissioning-data-on-half-a-million-objects-in-the-sky-from-the-galileo-project-observatory-are-a23bd084233aSource snippet
Data on Half a Million Objects in the Sky from...The GP Observatories offer an array of multi-modal, multi-spectral sensors that continu...
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Source: youtube.com
Link: https://www.youtube.com/watch?v=cKrW0aoB_6wSource snippet
ADS-B: The Future of Aircraft Surveillance! Explained by...ADSB is an advanced surveillance technology that allows aircraft to broadcast...
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Source: medium.com
Title: ufos and [radar]({{ ‘radar/’ | relative_url }}) targets clutter safety and false certainty c3eab7a878ad
Link: https://medium.com/%40timventura/ufos-and-radar-targets-clutter-safety-and-false-certainty-c3eab7a878adSource snippet
UFOs and Radar: Targets, Clutter, Safety, and False CertaintyFrom Washington 1952 to the Nimitz encounter, this story explores UFOs, rada...
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Source: adsadvance.co.uk
Link: https://www.adsadvance.co.uk/Source snippet
No responsibility or liability is accepted by ADS, the editorial team or the publisher for any loss...
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Source: researchgate.net
Title: 392334596 Galileo Project Observatory Class System Architecture
Link: https://www.researchgate.net/publication/392334596_Galileo_Project_Observatory_Class_System_ArchitectureSource snippet
(PDF) Galileo Project Observatory Class System Architecture30 May 2025 — This design and implementation paper describes the system lifecy...
Published: May 2025
-
Source: adsgroup.org.uk
Link: https://www.adsgroup.org.uk/Source snippet
ADS Group: HomeADS is the UK trade association advancing leadership in aerospace, defence, security and space, to enable prosperity and c...
-
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: Wikipedia
Title: NASA Unidentified Anomalous Phenomena Independent Study Team
Link: https://en.wikipedia.org/wiki/NASA_Unidentified_Anomalous_Phenomena_Independent_Study_TeamSource snippet
NASA Unidentified Anomalous Phenomena Independent...UAPs are defined as phenomena or observations of events in the air, sea, space, a...
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Source: nevadacurrent.com
Title: nasa report finds no evidence that ufos are extraterrestrial
Link: https://nevadacurrent.com/2023/09/18/nasa-report-finds-no-evidence-that-ufos-are-extraterrestrial/Source snippet
18 Sept 2023 — Analysis of this data is “hampered by poor sensor calibration, the lack of multiple measurements, the lack of sensor metad...
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