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Ground Penetrating Gadget Answered

Hello, out there,

I would like to find how to build a ground penetrating gadget. I think there are a lot of 'us' would like to have something that can 'peek' underneath the surface of the ground, not necessary very deep. For example, such a gadget that can help fossil hunting tremandously. And it does NOT have to go all the way to Ground Penetrating Radar. As long as it can detect the differences between the matrix and interested object up to say 50 cm in depth, it will be good enough. And it doesn't matter what physical principle is used: GPR, ultrasound, electrical resistance or capacitance, ... (whatever).

What I have in mind in such gadget would be tied to one of the shoes (so, it must be very light weight), using wifi to transmit the signal to iPad/iPhone so that the user can just walk and know the place to dig.

Any help or comment will be greatly appreciated.




6 years ago



6 years ago

So would a soil probe approach offer a more suitable solution?

Also there is some work being done on comparative soil and landscape types.


modifying a commercial gold detector would be nice for this :-)

Can you tell me more about gold detector? Thanks.

There is a branch of archaeology called "geophysics", which deals with this sort of thing.

One of their techniques is "resistivity", using a pair of probes on a frame, the electrical resistance of the soil and any buried features in it is measured: where there are buried pits and ditches, there is little resistance, whereas walls and stone give great resistance.

The probes are generally about 50cm apart, on a big wooden frame, but you could sacrifice some accuracy for portability by using contacts (or probes) on your shoes, with the electronics on a belt, maybe giving a varying, audible pitch with the values measured? If the data were stored, and linked to GPS data, you could later plot a map of the readings.

Wikipedia article

Relevant university link, with email address.

Google scholar results.

Also, google for geophysical survey, possibly fine-tuning with words like archaeology or techniques.

Thanks, Kiteman. Wiki gave me some directions to explore.

One interesting thing about the fossils (dinosaur or other animal fossilized bones) I'm searching for is that they usually contain about 1,000 more Rare Earth Elements (and Uranium) concentration than that of the surrounding matrix. This may provides a good lead for search a suitable way.

I would check the actual figures - a thousand times more, but more than what?

This will likely be a chemical analysis, rather than remote sensing, and they will certainly be present in the form of minerals, not elemental metals. Don't expect to be able to pick up the concentration-differences in the beep of a metal-detector.

(I may have mislead you earlier as well - drop the word "archaeology" from your searches, and replace it with "palaeontology".)

I did the chemical analysis of dinosaur bones by ICP and used the Rare Earth Elements to figure out relative dating of the dinosaur formation. What I mean of 1,000 times more is relative to the surrounding matrix, i.e., inside the bone, REE concentration is about 1,000 times more than the surrounding matrix. Also, I know the difference between elemental metal and their compound.

Since the fossilized bones contain 1,000 times of REE, density-, magneto-, and/or conductivity-wise may be different enough to be measured. Element Nd (one of the REE elements) is used to make super-magnet now-a-day.

Thanks for your suggestion.

You misunderstand me - a thousand times what value?

A thousand times a gramme per kilo of material? Or a thousand times a milligramme per tonne?

You're going to have to check your data - a thousand times 1,000ppm = 1,000,000ppm = pure substance.

In the matrix, the REE concentration is about several ppm, in the bones, several thousand ppm.

So, you're looking for mineral concentrations of less than 1%, remotely, through rock and regolith?

Unless you're looking for something highly radioactive, forget it. Even iron ores won't trigger a metal detector at that level.

You'll have a lot more success with your eyes and a trowel.

If some sort of signals are injected and the reflected are measured, what will be the result? Stud finder/ metal detector uses electric/magnetic field interruption for detection.

Furthermore, hopefully, this can go as deep as 50 cm. However, even 10 cm below the surface will make me very happy.

You're talking about ground-penetrating radar, which already exists, but the smallest available units are the size of a holdall.

It can penetrate way past 50cm, but, as I said, it cannot tell the differences between concentrations of minerals.

What you're demanding is unrealistic.

Landing on the moon and portable phone and many others were considered as unrealistic.

Some cars are equip with small radar for collision avoidance. That can be that big.

Now you're straying into woowoo; other completely unrelated concepts were considered unrealistic, but they're real, therefore my idea is real.

Not how the world works, I'm afraid.

You want a device on your shoe that cannot be smaller than a holdall - size is determined by the size of the aerial, the size of the aerial is determined by the frequency of signal used, the frequency required is determined by the substance you want to penetrate.

I repeat, you will have far more success with a trowel and your eyes.

You're asking someone to create a device that doesn't exist?
How many places have fossils less than 50 cm in depth under your feet?


Too many.

For example, the bad land of Montana, the hills of YunNan, China, many many thousands of square miles of dino-land.

Don't people just dig the place up and pick-out the fossils?
Are they in need of a sophisticated survey? (I don't know)


I believe in the 24th century they will have such a device. It can probe and scan distant planets and transport matter through time and space.

It should be available in the 20th century, not 24th.

But you have to find them first before you know where to dig.

I think your device would have to be tremendously accurate and need a high resolution to define the shape or boundary of the object. I think it would be hard to discern a fossilized fossil or shards from the surrounding soil/rocks if the composition does not vary greatly. Stud finders work up to a point where it still gives a lot of false readings and only capable of wall thickness up to about an inch or a few cm. If you have a portable x-ray or CT scan/MRI machine, it might be possible to map an area but it would be tough to get something that fits on a shoe.

No, I don't think the accuracy is that important, as long as it gives a beep or whatever telling me something to dig. Qualitative is more significant than quantative in this case. As stud finder, it doesn't matter if it is off a bit.

So, wandering if the little radar in the car (for avoid collision)will work or not?

I guess I am not understanding how you search for fossils. You would want a fish finder to tell you where one is swimming and if there are a school of fish down there. The trick is to determine the difference between a fossil and any other clump of organic matter that may be buried. Are you looking for trilobites or want to find some T-rex sized bones?

Yes, the key point is to detect the physical difference between fossil (patronized organism) and surrounding matrix. Density is one of variable can be used, resistance or capacitance are other factors can be used. Of course, other means can be used.

I search many different fossils, including trilobites, dinosaur, and others.

Don't be mislead by Jurassic Park - there is very little remotely-measurable difference in density or physical composition of most fossils compared to their matrix.

Geophysics will help you find water, voids, buried structures and rock-type boundaries, but for non-metallic items, you're going to have to dig and hope.