Tagged: metal detector

An RTL-SDR Based Ground Penetrating Radar & Metal Detector

Thanks to Dr. Celalettin Uçar from Turkey for submitting a video of the work done by a PhD student who as part of his research created an RTL-SDR based ground penetrating radar simulation and metal detector. He writes:

This apparatus (YAĞRIN) was created with rtlsdr in a phd work. We achieved detecting a metal gasoline tube from the depth of aproximately 1 meters. Furthermore, we created the time domain signal and ploted the reflaction from the metal with using the matlab (simulink) model.

A video on YouTube is linked which we display at the end of the post. They write that the system consists of a 12V DC supply, step down voltage regulator, ADF 4350 programmable signal generator, 25W power amplifier (470 MHz, 45 dBm signal power), Philips omnidirectional antennas (RX,TX), a 64 dB low noise amplifer and an RTL-SDR and computer to display the output. The software he uses is SDR# which appears to simply listen for a tone and detect any changes that occur when something metal moves near it. The PC also runs a MATLAB Simulink model which we believe helps detect metal signatures by plotting the reflection.

In the past we posted about a similar but simpler metal detector implementation by Ancient Discoveries.

Demonstrating an RTL-SDR Based Metal Detector

Over on YouTube user Ancient Discoveries has uploaded a video showing a prototype of his RTL-SDR based metal detector. The metal detector appears to consist of a coiled detection loop antenna powered by an AM transmitter and an RTL-SDR running in Q-branch direct sampling mode.

Ancient discoveries uses SDR# to tune to a low medium wave frequency of around 898 kHz while in direct sampling mode. Then as a piece of metal is moved closer and further from the detection coil the signals on the spectrum move around in correlation with the metals distance. A whining sound just like a real metal detector is also produced by SDR#.