Basics Of Ground Penetrating Radar

[Alex_Sor]

1 hour ago, principedeleon said:

Metal detectors seem to loose depth as the ground gets more mineralized.

Dark red clay with lots of black sand and hot rocks..  

This would probably be a ground that it havent been tested on but having atleast 8 feet of depth will be nice anyway ..

I can say, that several times I was invited to a company that was engaged in checking the ancient city of the times "Kiev Rus" (Ukraine) (about 1200 AD).

So, I checked the rest of the protective rampart around the city (what was left of it).

It was mostly clay (not wet), gray-yellow in color, and I was able to find remnants of burnt (fire and carbon-soot) bricks. They were at a depth of about 1 meter from the surface, metal detectors showed nothing (we had Lorenz with a 2.5 meter antenna carried by two people).

I was interested in the picture on the radar, and I reported that under us there may be hundreds of stoves, where there could be something interesting. We dug the object, and indeed there were burnt and covered with twisted soot stones.

Small metal objects are visible during post-processing of the radar profile (when you are in no hurry and can play a lot with display palettes). In my experience, approximately 30% of objects are in real-time when they pass in the field (field shooting). The rest 70% can be detected during post-processing, when there is time for many profile runs in a processing program with different mathematical filters.

 

For example, an object near the city of Kaliningrad. (former Germany). In this place, there was a suspicion of an underground bunker, in which there were some objects. We managed to shoot.

Filming (see the profile picture) showed the presence of an underground cavity with some boxes inside of which objects have a chaotic orientation. It is visible as "ripples up" above the boxes. See the picture.

Pay attention to the area (picture above) 300-450 (green numbers at the top of the scale). This is a screenshot from the georadar screen, Easyrad program. I have a "source file" of the footage and can play with it using different palettes and filters.

If I apply other filters, and cut the frequencies of the rad to high (cut off the low frequencies, i.e. leave only the return of frequencies from small objects), then I will get this picture:

Pay attention: it was the reflections of a higher frequency (from 480MHz to 800MHz) that appeared here and the "ripples" created by multiple reflections became more distinct.

If we leave only low frequencies (80-500 MHz), then we will more clearly see the bunker itself and something big in it (300-450 in green numbers):

 

 

Unfortunately, the bunker had a "secret", when trying to excavate the bunker, the excavator damaged the waterproofing, and the bunker was flooded with water ...

Unfortunately, the fate of the object is currently unknown. Due to the outbreak of the 2014 war.

 

[Alex_Sor]

Amber.

Real filming and real processing is in this video.

Set in the settings "show subtitles" and "translate into English".
( from 13:40 time )

 

And here is a photo of part of what we managed to lift from the depth ...

 

[Alex_Sor]

Winter work through the ice.

This is a picture of a real bed of an old river, under a layer of ice.

(Ice is radio-transparent)

Now there is a swamp in that place, but we were looking for the old river bed.

the first channel of river - on the green scale (top of the image) 50-200,

the second channel of river= 650-800.

Measurements were made across the river bed!

[Alex_Sor]

this is how the real riverbed looks like under water

Advanced processing is applied here.

Measurements were made across the river bed!

[Alex_Sor]

3D processing of measurements river bed from several profiles,

processing in the RadMax program.

[Alex_Sor]

Underground pipeline.

3D processing of measurements of several profiles, processing in the RadMax program.

( pipeline length = 34 meters )

[Alex_Sor]

test in the forest.

EasyRad GPR Pro GPR + RadMax software

 

 

[jasong]

What a great thread! Chalk me up as another person fascinated with what a prospector could do with GPR.

Like Steve, I am curious about searching for paleo river channels, buried and lost under sediment, except I am curious about searching for them in Nevada where the soil is quite salty.

I see from your chart that salt attenuates the radio waves quite a lot. What sort of depth might a person expect from your GPR in salty/alkaline soils? Does this attenuation decrease when the soil is dry versus wet, when the salt ions are not as mobile, and if so, how much more depth might be expected when the salty soil is dry?

Do you have any units in the US to demonstrate in the field?

[Alex_Sor]

Dear sirs ? 

1) dry salty (even just salt itself) soils break through well (low attenuation). Any crystalline rocks break through well, we can talk about 5-15 meters of depth. Wet (wet) salt rocks are electrolyte (like seawater) and have a very high attenuation.

2) America (USA) has made it almost impossible to visit with tourist visas. If someone took responsibility and made an invitation to one of us, we could bring a radar and travel (visit) places (fields) for measurements.

3) The cost of a radar complete with all antennas is about $8000. You could chip in money (put together money from several people) and buy one radar for several people, we could send you a radar and support you remotely.

4) Gold mining means you spend hundreds of thousands of dollars on digging and flushing equipment. If you do not have equipment for deep exploration (for example, georadar), then you will spend tens of thousands of dollars on fuel and blindly washing tons of rock, playing roulette - "lucky or unlucky." In Ukraine, many amber seekers have georadars, despite the fact that we are a poor country and for such a sum of money you can buy a house in a village in Ukraine  ?