Here is a clip from our recent GPR BOOTCAMP workshop. As the students and I were discussing how different materials affect GPR performance I answered a question about how the same antenna will produce waves of DIFFERENT wavelengths in different materials.
That means that a 100 MHz GPR antenna will actually have a longer wavelength in sand than it does in clay. This is one of the reasons that makes it difficult to identify targets at depth in materials with high relative dielectric permittivity.
However, an important fact that is often left out of these discussions is that shorter wavelengths in materials with higher dielectric constants will give better resolution. This, of course, is only true for the shallower depths at which the GPR can see in these contexts.
To find out more about upcoming live workshops go to http://learngpr.com.
LearnGPR.com is an online training platform for Ground Penetrating Radar that helps civil engineers, utility locators, and others learn about GPR through fun and engaging courses and coaching.