HD Laboratories can offer methods for high resolution imaging of NDT/NDE data, including ultrasonic, eddy current and radar formats.  A principal method is holography as explained below.

An ultrasonic hologram of five 1/4-inch diameter flat-bottom drill holes through 3 inches of aluminum
Holographic Image
Reconstructed holographic image of the drill holes.  Accurate flaw sizes may be scaled from the image.

Holographic images are obtained by computing the reflected energy profile existing directly at the flaw depth.  This will be a footprint of the flaw.  The computation is done by propagating the received C-Scan data back to the flaw depth.  This procedure utilizes simple spatial Fourier transforms and can be done rapidly.

Both tone burst and impulse data may be successfully imaged.  In either case, the Fourier amplitude coefficients of the raw data are collected at the frequency(ies) of interest.  The coefficients are back-propagated to the desired depth and converted to magnitude [(a^2 +b^2)^0.5].  Plotting magnitude as a function of lateral position produces the final image.

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