Methods and systems for characterization of an anomaly using infrared flash thermography

An apparatus for characterizing an anomaly in a material, the apparatus comprising:

• one or more processors;
• and
• one or more memory units coupled to the one or more processors,
• the apparatus being constructed and arranged to:
• extract contrast data;
• measure a contrast evolution;
• filter the contrast evolution;
• measure a peak amplitude of the contrast evolution;
• determine a diameter and a depth of the anomaly, wherein determining the diameter and the depth of the anomaly called the direct depth estimation comprises:
• calculating a multiplier M and a flaw size parameter Ac using an amplitude constant CA equal to one for a first iteration of determining the diameter and the depth for subsequent iterations of determining using an amplitude constant derived from an amplitude constant calibration curve;
• calculating an adjusted diameter to depth ratio γ′;
• estimating the depth of the anomaly using a diameter constant CD equal to one for a first iteration of determining the diameter and the depth and for subsequent iterations of determining using a diameter constant derived from a diameter constant calibration curve;
• estimating the diameter of the anomaly;
• comparing the estimate of the depth of the anomaly after each iteration of estimating to the prior estimate of the depth of the anomaly to calculate a change in the estimate of the depth of the anomaly;
• and
• repeat the act of determining the diameter and the depth of the anomaly until the change in the estimate of the depth of the anomaly is less than a set value.

A computer program product stored on a non-transitory computer operable medium, the computer program product comprising software code being effective to characterize an anomaly in a material by comprising a set of instructions to:

• extract contrast data;
• measure a contrast evolution;
• filter the contrast evolution;
• measure a peak amplitude of the contrast evolution;
• determine a diameter and a depth of the anomaly, wherein determining the diameter and the depth of the anomaly called the direct depth estimation comprises:
• calculating a multiplier M and a flaw size parameter Ac using an amplitude constant CA equal to one for a first iteration of determining the diameter and the depth and for subsequent iterations of determining using an amplitude constant derived from an amplitude constant calibration curve;
• calculating an adjusted diameter to depth ratio γ′;
• estimating the depth of the anomaly using a diameter constant CD equal to one for the first iteration of determining the diameter and the depth of the anomaly and for subsequent iterations of determining using a diameter constant derived from a diameter constant calibration curve;
• estimating the diameter of the anomaly;
• comparing the estimate of the depth of the anomaly after each iteration of estimating to the prior estimate of the depth of the anomaly to calculate a change in the estimate of the depth of the anomaly;
• and
• repeat the step of determining the diameter and the depth of the anomaly until the change in the estimate of the depth of the anomaly is less than a set value.