Can Ground Penetrating Radar Help Locate Earthquake Survivors?

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Discussion Overview

The discussion revolves around the potential use of ground penetrating radar (GPR) and sound identification techniques, such as frequency spectrum analysis, to locate survivors in the aftermath of the earthquakes in Syria and Turkey. Participants explore the feasibility of these technologies in chaotic collapse scenarios, considering both theoretical and practical aspects of search and rescue operations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose using GPR to detect survivors, but others argue that the chaotic nature of collapsed structures makes GPR interpretation difficult.
  • There is a suggestion that sound spectrum analysis could help locate survivors, although concerns are raised about distinguishing survivor sounds from background noise.
  • A participant suggests that the best strategy for survivors would be to create a distinct signal, such as hitting something three times, to aid in detection.
  • Concerns are expressed about the noise generated by the collapse and the time it takes for the structure to settle, which complicates sound detection efforts.
  • Some participants emphasize the importance of having earth-moving equipment available for effective rescue operations, potentially outweighing the need for advanced detection technologies.
  • There is a discussion about the limitations of using a lock-in amplifier for sound analysis, with suggestions for autocorrelation as an alternative method for detecting repeated patterns in audio signals.
  • A mention of software called phyphox is made, although its capabilities are questioned in the context of the discussion.

Areas of Agreement / Disagreement

Participants express multiple competing views on the effectiveness of GPR and sound analysis for locating survivors, with no consensus reached on the best approach. The discussion remains unresolved regarding the practicality of these methods in chaotic collapse situations.

Contextual Notes

Limitations include the dependence on the chaotic nature of collapsed structures, the challenges of noise interference, and the need for heavy equipment for effective rescue operations. The discussion also highlights the unresolved nature of sound detection techniques in such environments.

hagopbul
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TL;DR
Is it possible to use ground penetrative radar in searching for survivors in Turkey, Syria earthquake
Hello :

As the news coming from Syria and Turkey about earthquake devastation, is it possible to use ground penetrative radar or sound identification and wave frequency spectrum analysis to locate survivours ?

The human sound are in the range of 20 kHz shouldnt we be able to use microphones to record sound in the collapsed buildings and analysis that spectrum

In addition to other search and rescue nethods

For ground penetrating radars I don't know how the technology work other than Wikipedia

Best
Hagop
 
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hagopbul said:
TL;DR Summary: Is it possible to use ground penetrative radar in searching for survivors in Turkey, Syria earthquake

As the news coming from Syria and Turkey about earthquake devastation, is it possible to use ground penetrative radar or sound identification and wave frequency spectrum analysis to locate survivours ?
GPR works by looking for small differences in the ground EM parameters. After an earthquake, a collapsed building is chaotic and has many air spaces, which makes GPR very difficult, if not impossible to interpret.

You are concerned first with the limits to the detection of survivors. The second limiting factor to rescuing detected survivors is the mechanical removal of the collapsed structure. The third limiting factor is the availability of the medical attention necessary to treat crush injuries.

Survivors near the surface can be detected by trained animals, or by lowering microphones into cavities in the structure. Those are the survivors that might be reached by excavation during the next few days.
 
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Indeed , but could analysing the sound spectrum increase the possibility of locating survivours, there maybe a lot of noise , should frequency spectrum analysis help , we may not able to distinguish between survivour sound and noise from the area
 
hagopbul said:
... should frequency spectrum analysis help ...
Will you analyse for heartbeat or breathing? What is the characteristic that you might look for? The first survivors to be rescued will be those that call, and can be heard through the air spaces.

I believe the best strategy for a survivor would be to hit something three times, with the time spacing as regular as possible. That is an unusual signal that can be detected by a human ear with a brain, or by correlation instruments. If there is a response, repeat or echo the signal to confirm reception.

hagopbul said:
we may not able to distinguish between survivour sound and noise from the area
That will always be a problem. There will be many random impulses that will raise the noise floor across the entire spectrum. It will take a long time for the building to settle and become quiet after the initial destruction. To eliminate that impulse noise will take some fancy signal processing. Indeed, prior to listening, an artificial shock noise might reduce the noise floor by relief of the creeping stress in the heap of material.

I expect the provision of earth moving equipment is a more important investment than detection instrumentation. There is little advantage in detecting survivors who, due to a lack of heavy equipment, cannot be rescued.
 
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Of course providing earth moving equipments ie debris is important also locating survivours will reduce time taken and will provide better management for resources saving a lot of lives, until all the equipments be available to move all the debris can we repurpose a software to make it able to analysis the sounds from the debris that would be great addition to the current rescue efforts , can we use lock in amplifier to even make a better resolution? Public universities in Syria and Turkey may have it in their laboratories
 
hagopbul said:
... , can we use lock in amplifier to even make a better resolution?
In short, no.
A lock in amplifier needs a reference signal, it then operates as a synchronous detector. You could not guess the exact pulse rate or respiration rate of an unknown victim.

You could use some form of autocorrelation, where you look for repeated patterns in the audio signal.
https://en.wikipedia.org/wiki/Autocorrelation
It would take a long recording with much FFT processing, but then I cannot see how you might then locate the source of the signal in the unknown multi-path structure of a collapsed building.

The magnitude of the catastrophe has now been decided, but lessons can still be learned, and changes made. The first change should be to the enforcement of a seismic safe building design code. Maybe a prohibition on the insurance of buildings against earthquake damage, would force building owners to face the issue when rebuilding, and so save many more people in the future.
 
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There is an software called phyphox developed for rwth aachen I don't think it is considered fancy software
 
Thread closed for Moderation...
 
After a political tangent has been deleted, this thread will remain closed. The OP's question has been adequately answered (GPR is not useful in these kinds of chaotic collapse situations, and there are other techniques that are better and are being used in the current disaster). Hearts out to the victims and their loved ones in the Middle East.