Frequency modulated thermal wave imaging (FMTWI) has been successfully applied in the field of infrared thermography to estimate defects in various structural materials. The paper presents theoretical aspects of three-dimensional mild steel sample for FMTWI to detect flat bottom holes as defects. Furthermore, performance of FMTWI for analytical and simulated approach has been discussed and comparison has been performed based on time domain matched filtering pulse compression approach. The results demonstrate enhanced depth resolvability of the time domain-based pulse compression approach for FMTWI scheme.

中文翻译：

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调频热波成像技术用于低碳钢的红外无损检测

调频热波成像（FMTWI）已成功应用于红外热成像领域，以估算各种结构材料中的缺陷。本文介绍了用于FMTWI的三维低碳钢样品检测平底孔缺陷的理论方面。此外，还讨论了FMTWI在分析和模拟方法上的性能，并基于时域匹配滤波脉冲压缩方法进行了比较。结果表明，用于FMTWI方案的基于时域的脉冲压缩方法具有更高的深度可分辨性。