Preprocessing, Filtering, and Deconvolution

In InterSAFT we provide some techniques to improve the work with measured data. Usually, data of a real measurement are noisy, corrupted by externel influences and by limitations of the sending and transmitting devices. In addition, reflections outside the area of interest and multiple reflections from strong reflectors are superimposed on the useful data. This finally leads to artifacts in the reconstructed images.

When measuring on concrete objects, additional effects are obtained by the aggregate material, which causes local material inhomogeneities and disturbs the wave propagation depending on the frequency.

The preprocessing tools are only available as part of the processing in InterSAFT. Changes in parameter settings influence immediately the reconstructed image. In case of impulse echo data, the result of the preprocessing can be stored as ghk data files for further use.

TABLE OF CONTENTS

• Preprocessing Module
  • Overview
  • DC extraction
  • Reference subtraction
  • Energy Normalization
  • Average Subtraction
  • Surface Wave Suppression
  • Windowing the signal
• Filtering 1 Module
• Filtering 2 Module
• Deconvolution Module
  • Common Parameters
  • Filtering
  • Convolution, Correlation
  • Deconvolution, phase deconvolution