Claim: World’s First: Passive Radar Signal Confirms visual UFO-Sighting

MonkeeSage

MonkeeSage

Senior Member.
An article was published claiming that a UFO sighting has been confirmed via passive radar observation. The article is being posted on various social media, including by big names like Ross Coulthart.

The article is here and all quotes below are from the article unless otherwise noted.

https://www.grenzwissenschaft-aktue...ve-radar-signal-confirms-visual-ufo-sighting/

External Quote:
Luedenscheid (Germany) – Worldwide, private passive radar systems are increasingly being used in UFO research. In Germany, members of the "Society for the Investigation of UFO Phenomena" (GEP) also operate such systems. For the first time, one of these systems has successfully and independently confirmed a UFO sighting in real time – an unprecedented milestone in research.

DTLs about the case:
External Quote:
Case Summary
Case Number: 20240920 B
Date: September 20, 2024
Time: 05:34 AM CEST
Location: 77948 Friesenheim – Oberweier, Germany
Witnesses: Name known to investigator
Classification: NL
Assessment: GOOD UFO
Identification: None
Investigations: On hold
First Contact: Email, September 20, 2024
Investigator: Josef Garcia

External Quote:
The witness, an employee of the Federal Police in Offenburg, was returning home from a night shift and parked in front of her house. Upon exiting her car, she heard a loud noise coming from the southern sky, which she described as "the dragging of a metal chain over asphalt." Looking up, she saw a very bright, white, "wave-like" formation in the clear sky. In front of the wave-like structure, she observed a bright, vertically aligned "double dot." The sound stopped, and at the same time, the phenomenon disappeared. She estimated the sighting lasted no more than 5 seconds.

At the same time, the witness's husband was preparing breakfast in the kitchen and heard the loud noise through the open balcony door. However, he described it differently, saying it sounded "like many small beads falling onto a tiled floor." He did not step outside but found the unusual noise noteworthy for that early hour.

The witness was able to specify the exact time of the incident because she glanced at her Apple Watch, which displayed the time in large digital numbers (she uses this feature while jogging).

She lives approximately 1,000 meters from GEP investigator Josef Garcia, whom she knows personally and informed about the event shortly afterward. Unfortunately, Garcia was in the shower at the time of the event and did not hear anything, nor did his wife, who was still asleep.
External Quote:
1740616050261.png

Sketch of the sighting (top) and an inverted version (bottom) for better representation of the dark sky.
Source/Copyright: Witness/GEP, www.ufo-forschung.de


Information about the GEP investigation and radar capture:
External Quote:
A detailed interview with the credible eyewitness by Josef Garcia provided no further insights. Investigations into an independent source for the perceived noise yielded no results. The phenomenon was visible for only a very brief time, leaving the witness with no opportunity to observe additional details.

Josef Garcia is GEP's expert on passive radar, a valuable tool in technical UFO research. We previously reported on the technology and its applications in UFO research in JUFOF 257, 5-2021.

Both Garcia and GEP operate a station that continuously monitors part of the sky using passive radar.

1740616060295.png

Coverage of the Passive Radar at Josef Garcia's Location.
(The boundaries of the coverage are fluid and not as sharply defined as depicted in the image.)
Source: GEP, www.ufo-forschung.de

Since the unusual luminous phenomenon appeared within the coverage area of Garcia's passive radar station, it made sense to check the recorded signals from the time of the sighting. Indeed, the passive radar had captured a signal that closely matched the witness's sketch. We can therefore assume that the luminous phenomenon observed by the witness was the cause of the passive radar signal. This event is unprecedented worldwide. To our knowledge, this is the first time a UFO/UAP sighting has been confirmed using passive radar.

1740616082564.png

Screenshot of the Passive Radar Detection.
Source/Copyright: GEP, www.ufo-forschung.de

The radar recording also provides additional insights. The screenshot shows a time span of approximately 50 seconds. The interval between the left-side timestamps is roughly six seconds. The time is recorded in UTC, so two hours must be added to match Central European Summer Time.
External Quote:
Since the phenomenon was detected by passive radar, it must have been a tangible, luminous object rather than an immaterial "pure light phenomenon," comparable to an aircraft, helicopter, or meteoroid, all of which can also be registered by passive radar.
External Quote:
The light phenomenon's appearance is highly unusual and does not match any known UFO stimuli.

One could speculate about unconventional scenarios, such as a nighttime Zeppelin flight with a specific lighting configuration. However, this would be highly unlikely at that early morning hour. A review of air traffic data confirmed that no conventional aircraft were present in the area at the time.

1740616090303.png

Source/Copyright: GEP, www.ufo-forschung.de

Important points:

- The timestamps shown on the passive radar system screenshot are in UTC
- It is claimed no conventional aircraft were present in the area at the time


I am not familiar with passive radar so I don't know if that is a strange signature, but looking at the area on adsbexchange there is a B752 operated by DHL entering the passive radar coverage at almost the exact second the signal is detected (adsbexchange resolution is only 10 seconds and the passive radar area is stated to be approximate in the article, but it seems like a very good match for place and time).

https://globe.adsbexchange.com/?icao=3c70b0&lat=48.371&lon=7.833&zoom=12.3&showTrace=2024-09-20

1740614070582.png



Passive radar coverage area map from article overlaid on adsbexchange map:
1740614803288.png
 
Last edited:
I was thinking the witness may have observed a cloud to plane lightning strike, with the wavy line being the lightning bolt and the two dots being wing lights, which just happened to correspond with the plane entering the passive radar coverage area. The article claims the sky was clear but I would like to verify that.

External Quote:
The short duration of the sighting is another anomaly. If a conventional aircraft had caused the phenomenon, it would likely have been visible for a longer period. Lightning or similar natural phenomena can also be ruled out, as passive radar does not detect lightning. Moreover, meteorological data confirmed that the sky was clear.
https://www.grenzwissenschaft-aktue...ve-radar-signal-confirms-visual-ufo-sighting/

Does anyone know how to find historical meteorological information from the area, particularly cloud cover at various altitudes? On wunderground it has basic conditions, but nothing about cloud cover.

https://www.wunderground.com/history/daily/de/friesenheim/EDDF/date/2024-9-20
 
I am left wondering what exactly the eyewitness believes about what they saw.
Is the wavy line a physical object shaped like a wavy line? Or is it a trail left behind by a different object?
Are the two dots two seperate objects, or two lights attached to a single object?
What is the relationship between the wavy line in the sky and the wavy line from radar? A "radar picture" of the shape of a single object?
Is the wavy line on radar showing the path of the object that created the wavy line seen in the sky?
On the topic of passive radar, is the wavy line detected an instantaneous depiction of an object, or a trail created over time showing the movement of an object?
 
MonkeeSage said:
External Quote:
In front of the wave-like structure, she observed a bright, vertically aligned "double dot."
External Quote:
the passive radar had captured a signal that closely matched the witness's sketch.
External Quote:
View attachment 77732
Click to expand...

Well, you can call pure bullshit on that claim instantly.

In the witness' sketch, the y axis is spacial - specifically "vertical", in the radar plot the y-axis, as you note, is temporal, the chirp seems to be about 1s in length. Similarly, the x axis is almost certainly horizontal for the sketcher, and unless I'm misinterpretting the display (where's the axis in the plot - what are we actually measuring here?) the passive radar will be measuring frequency along that axis (so the vertical line is an intermittent pure tone).

space / space vs. frequency / time

Any "match" is pure coincidence.
 
I notice that in the screenshot of the passive radar it looks like it is tuned to 143.050MHz. This is the frequency of Graves Radar in France (47.3480°N 5.5151°E).

https://en.wikipedia.org/wiki/GRAVES_(system)

Also an example of passive ISS detection from the British Astronomical Association ;

https://britastro.org/section_infor...ons/mapping-radio-meteor-altitudes-for-graves

External Quote:
The GRAVES radar system near Dijon in France was designed to detect space objects in a wide arc, from due East through South to due West (see for example ) at elevation angles from 15° to 40°. Advantage is taken of this powerful transmitter for radio meteor detection and events can be detected from the radio observers across Europe. These meteor captures can be made for observers up to the radio horizon of meteor altitudes in the main (southern) beam. Many radio observers to the north of the Dijon line, indeed, some as far as the Scottish islands, detect very reasonable numbers of meteor events.
The PDF (Paper: GRAVES: The new French System for Space Surveillance) referenced by "see for example" is attached.

Graves is used by France for space object tracking and identification. It is a powerful VHF transmitter aimed skywards and uses solid state beam forming. One of the side effects of this system is being able to listen for meteor scatter signals. Where I am in the northern eastern part of the UK I can hear meteor pings, the ISS etc on a daily basis with a simple receiver and antenna. These are all doppler shifted in frequency - which is what the plot is showing, e.g. a moving object with respect to the observation receiver and also caused by passing through a swept radio beam.

In order to hear a radio reflection (passive radar) the object must pass through the beam pattern of the transmitted signal - a signal that is directed upward in France and moves in a repeating pattern. If you listen to such an event it is basically an audio tone which sweeps in frequency against time. I'm not aware the system has the resolution to outline the shape of a physical object. If the claim is that this "ping" comes from an object in German airspace then I'm a bit skeptical given the relative strength seen in the plot.

However, if you look down centre of that image, there is a faint trace from the tropospheric propagation of the radar signal - this is a direct path to the transmitter (there is no doppler shift seen). It is itself subject to aircraft scatter and atmospheric temperature ducting. if this is the case then there is some (weak) direct signal from Graves which could potentially be available for a more localised reflection. I would suggest that some form of Yagi (directional antenna with gain) is being used given the distance between Friesenheim and Broye-les-Pesmes, but as noted above the trace seems too strong to be a local reflection - but I don't know if the spectrum plot is compressed, so I remain on the fence at the moment esp. with respect to it's altitude and angle of reflection.
 

Attachments

Last edited:
Dave51c said:
However, if you look down centre of that image, there is a faint trace from the tropospheric propagation of the radar signal - this is a direct path to the transmitter (there is no doppler shift seen). It is itself subject to aircraft scatter and atmospheric temperature ducting. if this is the case then there is some (weak) direct signal from Graves which could potentially be available for a more localised reflection. I would suggest that some form of Yagi (directional antenna with gain) is being used given the distance between Friesenheim and Broye-les-Pesmes, but as noted above the trace seems too strong to be a local reflection - but I don't know if the spectrum plot is compressed, so I remain on the fence at the moment esp. with respect to it's altitude and angle of reflection.
Click to expand...
Awesome, I was hoping someone knows how all this stuff works! So a more likely candidate for the radar signal would be something like a satellite or meteorite more than a plane or other local object, if I am understanding correctly?
 
I ha
MonkeeSage said:
I am not familiar with passive radar so I don't know if that is a strange signature, but looking at the area on adsbexchange there is a B752 operated by DHL entering the passive radar coverage at almost the exact second the signal is detected (adsbexchange resolution is only 10 seconds and the passive radar area is stated to be approximate in the article, but it seems like a very good match for place and time).

https://globe.adsbexchange.com/?icao=3c70b0&lat=48.371&lon=7.833&zoom=12.3&showTrace=2024-09-20
Click to expand...
I have put the location and ADSB data into sitrec if it helps:

https://www.metabunk.org/sitrec/?custom=https://sitrec.s3.us-west-2.amazonaws.com/15857/Passive Radar UFO/20250227_111655.js
 
Dave51c said:
I notice that in the screenshot of the passive radar it looks like it is tuned to 143.050MHz. This is the frequency of Graves Radar in France (47.3480°N 5.5151°E).
Click to expand...

Do people actually call such displays "passive radar", as that's not radar, there's no directionality or ranging going on?
That looks like it's nothing more than the spectrum of the signal from presumably an SDR. To call it "radar", I'd want that signal processed to generate something more like this:
ksdr_pr_peak_web.png

image link: https://www.rtl-sdr.com/wp-content/uploads/2020/01/ksdr_pr_peak_web.png
via: https://www.rtl-sdr.com/kerberossdr-4-channel-rtl-sdr-passive-radar-with-peak-hold-display/ "RTL-SDR (RTL2832U) and software defined radio news and projects."

Do I see another example of peanut-butter logic:
This antenna and SDR can be used for passive radar
I'm using this antenna and SDR
Therefore I'm doing passive radar.
 
FatPhil said:
Well, you can call pure bullshit on that claim instantly.

In the witness' sketch, the y axis is spacial - specifically "vertical", in the radar plot the y-axis, as you note, is temporal, the chirp seems to be about 1s in length. Similarly, the x axis is almost certainly horizontal for the sketcher, and unless I'm misinterpretting the display (where's the axis in the plot - what are we actually measuring here?) the passive radar will be measuring frequency along that axis (so the vertical line is an intermittent pure tone).

space / space vs. frequency / time

Any "match" is pure coincidence.
Click to expand...
That's what I gathered, too. They're looking at a waterfall plot showing signal strength and frequency over time.

Yet they seem to believe they're looking at an actual picture of the sky, as though it were taken by a camera?
I'm really hoping I'm misunderstanding something myself here because that would be an utterly egregious misconception to base your 'investigation' off of.
 
FatPhil said:
Do people actually call such displays "passive radar", as that's not radar, there's no directionality or ranging going on?
Click to expand...
Yeah, technically it is not radar, but yes people do. Such is life and expediency.

I suppose "passively recording a radio reflection from a distant radio transmitter which happens to be a radar" is a more accurate term - but not exactly snappy. :)

A true passive radar could use multiple receivers for triangulation but without having control of the transmitter pulses, e.g. the SDR based kits around for that which you reference.
 
Easy Muffin said:
That's what I gathered, too. They're looking at a waterfall plot showing signal strength and frequency over time.

Yet they seem to believe they're looking at an actual picture of the sky, as though it were taken by a camera?
Click to expand...

From the explanation on how the graph would change under different settings I am under the impression that Mr. Garcia actually knows that the passive radar is actually a frequency/time plot:
External Quote:
However, if we assume it was indeed detected by the passive radar, then it must have been visible for only a very short time. Had it remained in the sky longer, the radar track visible in the screenshot would have looked different - it would have shown longer vertical amplitudes, and the two leading lights would have appeared as extended vertical streaks.
https://www.grenzwissenschaft-aktue...ve-radar-signal-confirms-visual-ufo-sighting/

I did a quick google search and found some interviews with Mr. Garcia in local news outlets. He seems to be just a normal hobby astronomer. Someone to ask for information about the newest meteor shower event for example:

The website "Grenzwissenschaft aktuell" however... Well it literally translates to "Current fringe science ... daily news from anomalistic, fringe- and parascience". I wouldn't rule out that Mr. Garcias technical explanations were a bit streamlined for a more interesting read.
 
MonkeeSage said:
Awesome, I was hoping someone knows how all this stuff works! So a more likely candidate for the radar signal would be something like a satellite or meteorite more than a plane or other local object, if I am understanding correctly?
Click to expand...
Yes, that would be my first thought given the reflection is from Graves Radar which has the power and beam direction into space for exactly that purpose and that the plot is showing the same.

Local aircraft reflections happen all the time. If there is a weak FM broadcast station some distance away that you are listening to and you are near a flight path which has airliners low enough in altitude you will hear the signal peak and dip providing the aircraft intersects the line between your receiver and the FM broadcast transmitter caused by multi path reflections and the angle it intersects.

That reflection will have doppler shift proportional to the speed of the aircraft. Airliners being big metallic reflectors - smaller private Cessna types need to be closer in to you for the same deviation in signal strength. (Just by simple area of reflection)

So you can have a simple local version of Graves if you will, but it will not be a UFO detector.
 
Ridcully said:
. I wouldn't rule out that Mr. Garcias technical explanations were a bit streamlined for a more interesting read.
Click to expand...
You're not suggesting that a simple spectrum plot was "reverse engineered" to provide a UFO story are you? Who would do such a thing? /s
 
Ridcully said:
From the explanation on how the graph would change under different settings I am under the impression that Mr. Garcia actually knows that the passive radar is actually a frequency/time plot:
External Quote:
the two leading lights would have appeared as extended vertical streaks.
Click to expand...

He seems to be confusing frequency bands, the SDR doesn't pick up visible wavelengths.

And apropos of nothing, simply because I'm in the reply editor, have a freebie GRAVES echo off the ISS caught by a (keen) amateur:
ISS-201710201615.gif

via: http://www.g4dbn.uk/?p=676 "GRAVES ISS reflections and doppler"
 
Dave51c said:
You're not suggesting that a simple spectrum plot was "reverse engineered" to provide a UFO story are you? Who would do such a thing? /s
Click to expand...
Well, that is certainly not unheard of. But to be fair it would also be entirely plausible that the writer of the article simple did not understood all of the technical details Mr. Garcia explained. Quite a lot of the articles on "Science News" themed websites leave that impression actually. Not every journalist has also studied physics. ;)
 
FatPhil said:
He seems to be confusing frequency bands, the SDR doesn't pick up visible wavelengths.
Click to expand...
Yes that part of the explanation doesn't make sense. It would be interesting to know if this is an actual quote from Mr. Garcia or just a faulty summary of the writer. However in the end that probably makes no difference for the analysis of the claim.
 
FatPhil said:
He seems to be confusing frequency bands, the SDR doesn't pick up visible wavelengths.
Click to expand...
and even if it did, the wavelengths of the lights would be identical, since they were reported to look the same, so there should only be a single mark (of some width)
 
MonkeeSage said:
I was thinking the witness may have observed a cloud to plane lightning strike, with the wavy line being the lightning bolt and the two dots being wing lights, which just happened to correspond with the plane entering the passive radar coverage area.
Click to expand...
External Quote:
Date: September 20, 2024
Time: 05:34 AM CEST
Location: 77948 Friesenheim – Oberweier, Germany
Article:
SmartSelect_20250227-170445_Samsung Internet.jpg

I found a single lightning strike recorded at ~5:35 CET (1 hour off the given time of observation), approximately 50 km south of Oberweier, near Freiburg. I do not know whether this site is limited to tracking lightning ground strikes.

Clear air lightning exists, but is rare.
 
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