Heterogeneous subsurface imaging systems and methods

A method for determining a subsurface feature, comprising:

• transmitting a surface penetrating radar (SPR) signal at a ground surface;
• receiving a response signal that includes elastic waves of a lower frequency acoustic source that interact with the SPR signal;
• rapidly processing the response signal including the SPR signal modified by the interaction with the elastic waves;
• and
• determining a physical characteristic of the subsurface feature from the response signal, wherein the elastic wave includes an induced low frequency continuous elastic wave propagating away from a focus region measured using the SPR signal so that at various phases of a low frequency modulation, pulsed waves are sent into the ground surface and back-scattered signals are received and used to create a time sequence of images formed by the SPR signal.

A method for determining a subsurface feature, comprising:

• transmitting a surface penetrating radar (SPR) signal at a ground surface;
• receiving a response signal that includes elastic waves of a lower frequency acoustic source that interact with the SPR signal;
• rapidly processing the response signal including the SPR signal modified by the interaction with the elastic waves;
• and
• determining a physical characteristic of the subsurface feature from the response signal;
• and
• performing a dynamic multi-wave imaging operation that provides for detecting small-scale spatially varying signatures through active perturbing and probing of mechanical properties in order to characterize subsurface structures.

A method for determining a subsurface feature, comprising:

• transmitting a surface penetrating radar (SPR) signal at a ground surface;
• receiving a response signal that includes elastic waves of a lower frequency acoustic source that interact with the SPR signal;
• rapidly processing the response signal including the SPR signal modified by the interaction with the elastic waves;
• and
• determining a physical characteristic of the subsurface feature from the response signal;
• performing a stacking operation, wherein a signal-to-noise ratio is increased by stacking repeated acoustic pulses and/or probing radar signals;
• and
• performing a dynamic multi-wave imaging operation that provides for detecting small-scale spatially varying signatures through active perturbing and probing of mechanical properties in order to characterize subsurface structures.