you wanna built easy GPR

[AK48]

https://hackaday.io/project/175115-gprino

[Funfinder]

This is a good approach but I would be careful or better said critical and skeptical about the outcome.

1. it is good because we don't need far too expensive GPR's
but
2. we also don't wanna have completely misleading screen- or other signal-outputs!

3. the Arduino board might be to weak for such tasks, but thats maybe a question of upgrades etc.

So the best solution would be a highly accurate GPR based on analog to digital Laptop input combined with a flexible and updateable software, because in fact all what you need is a transmitter and receiver of some 50-500 MHz which detects the reception differences !!!

In principle this is the same as with modern "smartphone MDs" but with higher frequency and a little bit different screen output.

[Krzysztof]

Yes, a good project based on academic constructions from a decade ago made at MIT - USA and Orpheus - EU, has great educational value.
The use of Arduino 2560 is completely sufficient (load below 50%), the screen is also enough for a cursory inspection in the field.
The problem is the Vivaldi antennas used, which begin to behave well only above 700MHz (checked with nVNA), and the operating range is 400 - 900MHz.
The processor also properly handles the SD card and communication via RS /USB with any graphics program in the computer (of course, after completing the measurements).
I made this construction by making a lot of changes to the software to make my life easier.
The PCB and parts list remained unchanged, I introduced automatic measurement repetition and variable gain to see the effects on the home desk, and since I have everything here, I see a lot of noise when gaining e exp 4.
I'm now looking forward to a dry spring to test GPR in the field with different UVB antennas; it is possible that you will still need to add amplifiers in the Tx and Rx track.
I recommend the project to hobbyists with a passion for UHF constructions.

[jeep6789]

What I want to know is, does the GPR react directly to metal, how much metal does it need to react, or the void, how big does it need to be? How is it different from the magnetometer?

[jeep6789]

Many people say that the madel is just a high name, and the actual use effect is not good. It needs a flat terrain. It does not respond to small objects, which is far less than a metal detector.