Can Ground Penetrating Radar Help Locate Earthquake Survivors?

[hagopbul]

TL;DR Summary

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

 

[Baluncore]

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.

 

[hagopbul]

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

 

[Baluncore]

... 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.

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.

 

[hagopbul]

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 alot 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

 

[Baluncore]

... , 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.

 

[hagopbul]

There is an software called phyphox developed for rwth aachen I don't think it is considered fancy software

 

[berkeman]

Thread closed for Moderation...

 

[berkeman]

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.