How deep can a microwave penetrate a rock?

The FINDER victim detection radar developed at JPL can detect heartbeats through 5-10 meters of rock using microwave signals. Penetration of radio waves isn't a "go to this depth and stop", it's a gradual fading away. read more

The FINDER victim detection radar developed at JPL can detect heartbeats through 5-10 meters of rock using microwave signals. Penetration of radio waves isn't a "go to this depth and stop", it's a gradual fading away. A typical rule of thumb is about 5-10 dB/meter attenuation. That is, after a meter, the signal is 1/3 to 1/10th as strong as it was. read more

The penetration depth of X-rays in water as function of photon energy. Penetration depth is a measure of how deep light or any electromagnetic radiation can penetrate into a material. It is defined as the depth at which the intensity of the radiation inside the material falls to 1/e (about 37%) of its original value at (or more properly, just beneath) the surface. read more