Defect Localization in Composites Using AI-Augmented Thz Imaging

1. Wang, B., Zhong, S., Lee, L., Fancey, K.S., Mi, J.: Nondestructive testing and evaluation of composite materials/structures: A state-of-the-art review. Adv. Mech. Eng. (2014). https://doi.org/10.1177/168781402091376110.1177/1687814020913761 ↗

2. Gholizadeh, S.: A review of nondestructive testing methods of composite materials. Procedia Struct. Integr. 1, 50–57 (2016). https://doi.org/10.1016/j.prostr.2016.02.00810.1016/j.prostr.2016.02.008 ↗

3. A. M. Latha, R. Ranjan and V. Petley, "Terahertz-Based Nondestructive Testing of Ceramic Matrix Composites," 2024 IEEE Space, Aerospace and Defence Conference (SPACE), Bangalore, India, 2024, pp. 841–844, https://doi.org/10.1109/SPACE63117.2024.10668341.10.1109/SPACE63117.2024.10668341 ↗

4. A. Mercy Latha, Supriyanka Rayapureddy, Nirmala Devi, Prabhu Rajagopal, Krishnan Balasubramaniam, Bala Pesala, "Rapid nondestructive evaluation of defects in GFRP composites using terahertz line scanner," Proc. SPIE 11279, Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XIII, 1127917 (2 March 2020); https://doi.org/10.1117/12.254592210.1117/12.2545922 ↗

5. Kumar, B.N., Kumar, M.C.S., Nallaperumal, M., et al.: Nondestructive evaluation of cryofoam with uneven surface by continuous wave terahertz imaging using dynamic depth focusing technique. J. Nondestruct. Eval. 42, 103 (2023). https://doi.org/10.1007/s10921-023-01015-y10.1007/s10921-023-01015-y ↗

6. Jin, Qi., Yu, H., Meng, Z., Fei, F., Li, Z.: Detection of impact damage in glass fibre-reinforced polymer composites using a microwave planar resonator sensor. Nondestruct. Test. Eval. (2023). https://doi.org/10.1080/10589759.2023.227400310.1080/10589759.2023.2274003 ↗

7. Garcea, S., Wang, Y., Withers, P.: X-ray computed tomography of polymer composites. Compos. Sci. Technol. 156, 305–319 (2018). https://doi.org/10.1016/j.compscitech.2017.10.02310.1016/j.compscitech.2017.10.023 ↗

8. Papa, I., Lopresto, V., Langella, A.: Ultrasonic inspection of composites materials: application to detect impact damage. Int. J. Lightweight Mater. Manuf. 4(1), 37–42 (2021). https://doi.org/10.1016/j.ijlmm.2020.04.00210.1016/j.ijlmm.2020.04.002 ↗

9. Kidangan, R.T., Unnikrishnakurup, S., Krishnamurthy, C., Balasubramaniam, K.: Induction thermography for unidirectional CFRP composites: a novel inspection approach through global current path integration. Compos. Struct. 327, 117678 (2023). https://doi.org/10.1016/j.compstruct.2023.11767810.1016/j.compstruct.2023.117678 ↗

10. Latha, A.M., Unnikrishnakurup, S., Jain, A., et al.: Material characterization and thickness measurement of iron particle reinforced polyurethane multi-layer coating for aircraft stealth applications using THz-time domain spectroscopy. J. Infrared Milli. Terahertz Waves 43, 582–597 (2022). https://doi.org/10.1007/s10762-022-00874-210.1007/s10762-022-00874-2 ↗

11. Kumar, B.N., Kumar, M.C.S., Latha, A.M., Aroliveetil, S., Nallaperumal, M., Balasubramaniam, K., Remakanthan, S., Moideenkutty, K.K., Nair, S.S., Kumar, L.M.: Thickness measurement of polychlorotrifluoroethylene coating over metallic seal using terahertz time-domain spectroscopy. Nondestruct. Test. Eval. 39(7), 1869–1885 (2023). https://doi.org/10.1080/10589759.2023.227402010.1080/10589759.2023.2274020 ↗

12. Umadevi, K., Sundeep, D., Latha, A.M., et al.: Enhancement of diagnostic accuracy in endometrial carcinoma using CW-THz spectroscopy. Indian J. Gynecol. Oncol. 22, 100 (2024). https://doi.org/10.1007/s40944-024-00872-310.1007/s40944-024-00872-3 ↗

13. S. M, G. K, Girish, S. P. Prabha and A. Mercy Latha, "Exploring the Capability of Terahertz Imaging for Oral Diagnosis," 2024 International Conference on Recent Innovation in Smart and Sustainable Technology (ICRISST), Bengaluru, India, 2024, pp. 1–4, https://doi.org/10.1109/ICRISST59181.2024.10921957.10.1109/ICRISST59181.2024.10921957 ↗

14. A. Jagdale, N. Devi, and A. M. Latha, "Advanced Image Processing for Rapid Threat Object Identification in Terahertz Images," in Proc. IEEE Int. Conf. on Unmanned Aircraft Systems (ICUAS), Sep. 2021, https://doi.org/10.1109/ucmmt53364.2021.9569943.10.1109/ucmmt53364.2021.9569943 ↗

15. Gui, S., Yang, Y., Li, J., Zuo, F., Pi, Y.: THz radar security screening method for walking human torso with multi-angle synthetic aperture. IEEE Sens. J. 21(16), 17962–17972 (2021). https://doi.org/10.1109/JSEN.2021.308381610.1109/JSEN.2021.3083816 ↗

16. Yim, J.H., Kim, S.-y, Kim, Y., Cho, S., Kim, J., Ahn, Y.H.: Rapid 3D-imaging of semiconductor chips using THz time-of-flight technique. Appl. Sci. 11, 4770 (2021). https://doi.org/10.3390/app1111477010.3390/app11114770 ↗

17. S. Brinkmann, N. Vieweg, G. Gärtner, P. Plew and A. Deninger, "Towards quality control in pharmaceutical packaging: Screening folded boxes for package inserts," 2016 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), Copenhagen, Denmark, 2016, pp. 1–2, https://doi.org/10.1109/IRMMW-THz.2016.7758570.10.1109/IRMMW-THz.2016.7758570 ↗

18. K. S. M, A. Rao, K. Kumar and T. R. Rao, "Terahertz Imaging for Aerospace Applications," 2023 International Conference on Wireless Communications Signal Processing and Networking (WiSPNET), Chennai, India, 2023, pp. 01–05, https://doi.org/10.1109/WiSPNET57748.2023.10134245.10.1109/WiSPNET57748.2023.10134245 ↗

19. Akhai, Shalom, et al. "Advancing Aerospace Inspection With Terahertz Technology." New Innovations in AI, Aviation, and Air Traffic Technology, edited by Saifullah Khalid and Neha Nazneen Siddiqui, IGI Global Scientific Publishing, 2024, pp. 195–211. https://doi.org/10.4018/979-8-3693-1954-3.ch01010.4018/979-8-3693-1954-3.ch010 ↗

20. A. M. Latha, S. Esampelly and A. S. N. Devi, "Terahertz Image Reconstruction using Compressive Sensing," 2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz), Delft, Netherlands, 2022, pp. 1–2, https://doi.org/10.1109/IRMMW-THz50927.2022.9895856.10.1109/IRMMW-THz50927.2022.9895856 ↗

21. Vijayalakshmi, S., Mrudhula, S., Ashok Kumar, Varun, Agastin, A. Mercy Latha, "Artificial Intelligence-Driven Timber Wood Defect Characterization from Terahertz Images," J Nondestruct Eval 43, 116 (2024). https://doi.org/10.1007/s10921-024-01130-4.10.1007/s10921-024-01130-4 ↗

22. A. M. Latha, R. Francis, B. S. Gayathri and R. Ranjan, "Few-shot Learning for Defect Classification from Terahertz Images using Siamese Network with Triplet Loss Function," 2024 IEEE Microwaves, Antennas, and Propagation Conference (MAPCON), Hyderabad, India, 2024, pp. 1–4, https://doi.org/10.1109/MAPCON61407.2024.10922995.10.1109/MAPCON61407.2024.10922995 ↗

23. Xi Yang, Tan Wu, Lei Zhang, Dong Yang, Nannan Wang, Bin Song, Xinbo Gao, "CNN with spatio-temporal information for fast suspicious object detection and recognition in THz security images," Signal Processing, Volume 160, 2019, Pages 202–214, ISSN 0165–1684, https://doi.org/10.1016/j.sigpro.2019.02.029.10.1016/j.sigpro.2019.02.029 ↗

24. Yang, X., Liu, P., Wang, S., Wu, B., Zhang, K., Yang, B., Wu, X.: Defect detection of composite material terahertz image based on faster region-convolutional neural networks. Materials 16, 317 (2023). https://doi.org/10.3390/ma1601031710.3390/ma16010317 ↗

25. Lu, Y., Mao, Q., Liu, J.: A deep transfer learning model for packaged integrated circuit failure detection by terahertz imaging. IEEE Access 9, 138608–138617 (2021). https://doi.org/10.1109/ACCESS.2021.311868710.1109/ACCESS.2021.3118687 ↗

26. Zhang, J., Xing, W., Xing, M., Sun, G.: Terahertz image detection with the improved faster region-based convolutional neural network. Sensors 18, 2327 (2018). https://doi.org/10.3390/s1807232710.3390/s18072327 ↗

27. Shouxian Wen, Wen Tang, Zhi Liu, Weiming Li, "Cigarette detection in express packages for terahertz imaging based on YOLOv8," Proc. SPIE 13657, Second International Conference on Power Electronics and Artificial Intelligence (PEAI 2025), 1365742 (30 June 2025); https://doi.org/10.1117/12.306712410.1117/12.3067124 ↗

28. Chandel, S., Bhatnagar, G., Kowalski, M.: A novel framework for concealed weapons detection using passive terahertz imaging. Nondestruct. Test. Eval. 40(7), 3208–3232 (2024). https://doi.org/10.1080/10589759.2024.240058810.1080/10589759.2024.2400588 ↗

29. Yang, X., Liu, P., Wang, S., Wu, B., Zhang, K., Yang, B., Wu, X.: Defect detection of composite material terahertz image based on faster region-convolutional neural networks. Materials 16(1), 317 (2022). https://doi.org/10.3390/ma1601031710.3390/ma16010317 ↗

30. Danso, S.A., Liping, S., Hu, D., Afoakwa, S., Badzongoly, E.L., Odoom, J., Muhammad, O., Mushtaq, M.U., Qayoom, A., Zhou, W.: An optimal defect recognition security-based terahertz low resolution image system using deep learning network. Egypt. Inform. J. 24(3), 100384 (2023). https://doi.org/10.1016/j.eij.2023.05.00910.1016/j.eij.2023.05.009 ↗

31. Ziling Xu et al 2025 Meas. Sci. Technol. 36 085206. https://doi.org/10.1088/1361-6501/adf98910.1088/1361-6501/adf989 ↗

32. Mian, Z., Hongxing, X., Fei, L., et al.: Nondestructive testing and predictability of microcracks in carbon fiber-reinforced composites via terahertz time-domain spectroscopy. Russ. J. Nondestruct. Test. 60, 96–103 (2024). https://doi.org/10.1134/S106183092360081810.1134/S1061830923600818 ↗

33. A. M. Latha and R. Ranjan, "Development of a Compact and Portable Terahertz Imaging System for Industrial Applications," 2024 IEEE Microwaves, Antennas, and Propagation Conference (MAPCON), Hyderabad, India, 2024, pp. 1–4, https://doi.org/10.1109/MAPCON61407.2024.10922892.10.1109/MAPCON61407.2024.10922892 ↗

34. M. Ali, R. C. Guzman, A. Rivera-Lavado, O. Cojocari, L. E. Garcia-Mufioz and G. Carpintero, "Quasi-Optical Schottky Barrier Diode Detector for mmWave/sub-THz Wireless Communication," 2018 25th International Conference on Telecommunications (ICT), Saint-Malo, France, 2018, pp. 279–282, https://doi.org/10.1109/ICT.2018.8464871.10.1109/ICT.2018.8464871 ↗

35. R. Varghese and S. M., "YOLOv8: A Novel Object Detection Algorithm with Enhanced Performance and Robustness," 2024 International Conference on Advances in Data Engineering and Intelligent Computing Systems (ADICS), Chennai, India, 2024, pp. 1–6, https://doi.org/10.1109/ADICS58448.2024.10533619.10.1109/ADICS58448.2024.10533619 ↗

36. Le, NT., Thai, N., Bui, C. (2025). Benchmarking Real-Time Object Detection: Evaluating YOLO and RT-DETR on Speed, Accuracy, and Efficiency. In: Buntine, W., Fjeld, M., Tran, T., Tran, MT., Huynh Thi Thanh, B., Miyoshi, T. (eds) Information and Communication Technology. SOICT 2024. Communications in Computer and Information Science, vol 2351. Springer, Singapore. https://doi.org/10.1007/978-981-96-4285-4_1910.1007/978-981-96-4285-4_19 ↗

37. https://cocodataset.org/#home

38. Yuying Jiang, Mengdie Jiang, Tauseef Abbas, Hongyi Ge, Xixi Wen, Hao Chen, “Detection of wheat impurities using terahertz imaging technology and deep learning”, LWT, Volume 229, 2025, 118201, ISSN 0023–6438, https://doi.org/10.1016/j.lwt.2025.118201.10.1016/j.lwt.2025.118201 ↗