SBIR-STTR Award

This proposal describes a 3-D bistatic radar imaging system to visualize the interior of man-made structures for non-destructive evaluation (NDE) and for detection of camouflaged targets. By use of a microwave sensor, penetration through obscuring media is feasible and therefore images of objects that are obscured by materials of various dielectric constants are reconstructed. The backscatter received from obscured, scaled-down versions of targets are collected in a test facility and first processed to ensure good image quality by reducing sidelobe levels, compensating for motion errors, and improving target-to-clutter ratio using unique signal processing techniques. The 3-D image is formed using a modified backprojection algorithm in a Quad-tree configuration for fast processing. The proposed system is a significant improvement over traditional 2-D monostatic radar imaging systems and has applications to both civilian and military systems (3-D images of a simulated landmine buried 6 deep are presented). In Phase I of this work, we develop the 3-D imaging algorithm, conduct simulations using Method of Moments (MoM) modeling software, and collect initial limited angle data of scaled obscured targets. Phase II will concentrate on performing benchmarking experiments and developing software for complete automation of data acquisition and image display.

Benefits:
The proposed 3-D imaging system can be configured to mount on a military vehicle for development of a forward looking mine detection system for the U.S. Army. This would allow for detection of buried mines and buried unexploded ordnances (UXO). Commercial applications include the Non-destructive evaluation of roads and bridges as well as detection of buried wires, pipes, and other structures. This evaluation and detection could be achieved by simply driving over areas of interest with a vehicle equipped with the proposed system

The use of microwave sensors for imaging continues to grow for applications such as target detection, airport screening, soil moisture estimation, etc. Hence, there is a need for indoor microwave imaging facilities but current facilities are not flexible enough to work in many different imaging scenarios such as bistatic and monostatic , 2D and 3D and full polarimetric imaging over a large range of frequencies (45 MHz - 20 GHz). These scenarios are important for many applications such as volumetric scattering, interferometric processing, ground penetrating analysis, etc. In Phase II we will develop a semi-portable microwave imaging device that works in all the scenarios mentioned above in order to satisfy a large variety of users. The flexibility of the device relies on our modified convolution backprojection (MCBP) imaging algorithm developed in Phase I and results will be presented. The MCBP can form a 2D and 3D image using both bi- or monostatic data and for any combination of transmit and receive antenna locations. In Phase II we will construct the prototype and integrate it with the MCBP then use the prototype in a bistatic and monostatic facility to form 2- and 3D imagery of targets. Potential customers expressed strong interest in our proposed product. Benefits commercial and military users of RF/microwave sensors that operate between 45 MHz - 20 GHz for such application as concealed weapon detection, soil moisture estimation, camouflage concealment and deception (CCD) research, materials research, buried mine detection, non-destructive evaluation (NDE) of bridges and roads, automobile guidance, medical imaging, and more.

Keywords:
microwave, sar, bistatic, 3d, imaging, radar, monostatic