## Subsurface imaging technology to reveal the unseen

### Subsurface Imaging Technology

The term “subsurface” means “beneath the surface of an object.” Subsurface imaging technology is a core technology of IGS and can be used to observe and analyze waves that have been scattered inside an object and propagated to the surface, which in turn reveals the inner structure and state of the object. This technology is realized using our theory (scattered field theory), which we were the first to derive, and advanced engineering.

### Wave Scattering field theory

##### A “world first” imaging theory derived from the solution to the “inverse problem of wave scattering,” which is an unsolved problem in the field of applied mathematics.

IGS is researching theory and methods for analyzing the internal structure of objects. The foundation of the methodology is based on observing waves emanating from the interior of an object at the object’s surface and using this to visualize the internal structure. In this manner, the information obtained on the surface of an area is used to computationally derive the information inside the area. The main problem here is the question “What kind of solution based on what kind of equation should be used to reconstruct the 3D structure of an object via observation results from its surface?”

If an object is composed of a “medium” and a “region whose physical properties are different than those of the medium” and if all these physical properties are understood, the observed signal can be calculated using the fundamental equations described in physics textbooks. However, in the case of observation, little is known in advance regarding the object. Conversely, observation can be described as “tracing causal relationships in physics in the reverse direction.”

##### Important conditions when tracing causal relationships in physics in the reverse direction

The following three points are important while tracing causal relationships in physics in the reverse direction.

- Ensuring a solid mathematical basis as in the aforementioned forward direction problem.
- The electrical and mechanical configuration of the observation system must be sufficiently versatile such that it does not change every time there is a change in measurement conditions.
- Availability of an algorithm with which one can perform the calculation in a reasonable amount of time using a commercially available computer.

Provided these conditions, we were the first in the world to successfully and analytically solve the inverse problem of wave scattering, an important problem that had been unsolved in the history of applied mathematics. This is the “Scattering Field Theory/Inverse Analysis Theory of Wave Scattering.” Regarding the problem of how to theoretically determine the internal structure of an object via irradiating waves onto the object and observing the scattered waves, we can derive partial differential equations in a multidimensional space to be satisfied by the scattering field and solve the observed results as boundary values to reveal the structure of the interior of the object through limit operations in time and space.

##### IGS solutions are supported by analytical theories for a number of inverse problems

The theories supporting the IGS technology do not only contain “Scattering Field Theory/Inverse Analysis Theory of Wave Scattering.” Provided that innovative fundamental theories are essential to providing new solutions, we are constantly working on researching fundamental theories.

### Ultra-sensitive sensing technology

##### Ultra-sensitive, ultra-responsive sensor technology for measuring electromagnetic fields from objects

IGS can achieve high-sensitivity, high-resolution measurements with an ultrahigh-definition radar technology, a sensing technology, and other technologies. The said ultrahigh-definition radar is a multistatic array antenna configuration comprising multiple ultra-wideband (UWB) active antenna elements, and it is capable of UWB measurements from DC to several dozen GH. In addition, it has extremely satisfactory noise-proof properties, thus enabling biometric measurements even with weak radiowaves. The solutions provided by IGS include quality control failure analysis for rechargeable batteries and security systems.

Microwave Mammography Measurement Devices

Nondestructive diagnostic system device for imaging rechargeable batteries

### Leveraging visualization technology

to address a wide range of social issues.

IGS’s objectives are to solve the “issues facing mankind,” and “mathematical visualization,” one of its core technologies, is being used to tackle various social issues. Solutions provided by IGS are constantly linked to social issues, and new solutions are being created with the aim of continued issue resolution.

IGS core technologies have high potential for development and are applicable to all fields. We will continue to develop and research new solutions.

### Our visualization solutions

### Technologies of IGS

[Dialogue] Professor Kenjiro Kimura × Takako Zenba

We have derived the mathematical equation that governs all phenomena of wave scattering. This formula can be used to instantly reconstruct the 3D structure of an object via scattered wave ripples, and it is no exaggeration to say that there are no limits to the fields to which it can be applied.