Data Collection Technique Breakdown #1

What is Ground Penetrating Radar? (GPR)

This is going to be a short rip from one of my research papers I submitted for school. I hope it it gives insight on a pretty useful tool in data collection. Note: this is in terms that I was taught and the terms may differ from geologist to geologist.

Ground penetrating radar (GPR) is a method of collecting data. GPR sends electromagnetic waves into the Earth’s surface in order to get an image of the sub-surface layers and the geometry of those layers. The position of this data can be determined by using a global positioning system (GPS). Typically, GPR has a setup that involves a control unit attached to a computer that is being tower behind a vehicle with an antenna attached or placed inside of the vehicle. It also has an odometer to keep a record of the distance traveled and helps keep the electromagnetic pulse on a consistent interval. The antenna is used to send the electromagnetic pulses that the control unit triggers. This pulse sends a wave into the sublayers which eventually reflects back to a receiving antenna. Depending on the frequency used, different depths and items can be seen with different accuracies. Qualities of the reflectors can reveal different characteristics of the sublayers. Amplitude indicates how similar an environment is. Transparency indicates areas of no reflectors such as muds. Frequency indicates how far apart each reflector is spaced from one another. Chaotic reflectors can indicate igneous rocks, limestone, or gas pockets.

Image Source

The above picture is similar to the device that my class used to collect data for the paper, but ours was not this new.
This paper was over land migration and ridge analyzation over a ridge system on the east coast of the US. I can go over how to analyze gpr lines in another post if anyone wants me to.