A Data Processing Chain for Terahertz Imaging and Its Use in Artwork Diagnostics

2016 ◽  
Vol 38 (4) ◽  
pp. 518-530 ◽  
Author(s):  
Ilaria Catapano ◽  
Francesco Soldovieri
Keyword(s):  
Data Processing ◽  
Terahertz Imaging ◽  
Processing Chain

Comparative study of steel corrosion characterization by visible and THz imaging techniques

2020 ◽  
Author(s):  
Jean Dumoulin ◽  
Ilaria Catapano ◽  
Jean-Marc Moliard ◽  
Giovanni Ludeno ◽  
Thibaud Toullier ◽  
...  
Keyword(s):  
Comparative Study ◽  
Data Processing ◽  
Infrared Thermography ◽  
Composite Structures ◽  
High Speed ◽  
Imaging Techniques ◽  
Terahertz Imaging ◽  
Data Matrix ◽  
Processing Chain

<p>Transport infrastructures play a significant role in the economy of countries. However, in European countries, transport infrastructures aging (>40 years) and traffic increase require to develop in-situ efficient inspection and maintenance solutions. Monitoring of steel and composite structures are important issues for sustainability of existing and new infrastructure. Classical approach relies on large human activities eventually performed in unsafe conditions. To overcome the problem on site contactless global automated measurement methods are to be favoured.</p><p>For apparent corrosion, visible imaging coupled with image processing allows to detect and characterize the extension of the defective area. Anyway, characterization of corrosion thickness and nature require complementary measurements. Among imaging techniques, knowing that corrosion acts as a insulating layer, active infrared thermography is a possible approach [1-2]. But here we will focus on the complementary approach based on THz-TDS imaging as investigated and tested for corrosion detection under painting with preliminary corrosion type classification [2].</p><p>In the present study, we first performed a measurement campaign on several steel samples at different corrosion stages. Typically, three stages were investigated: from non-corroded with paint coating, to pitting corrosion up to fully corroded sample surface.</p><p>Data were gathered by means of the Z-Omega Fiber-Coupled Terahertz Time Domain (FICO) system working in a high-speed reflection mode and were processed by using a properly designed data processing chain recently proposed in [3] and involving a noise filtering procedure based on the Singular Value Decomposition (SVD) of the data matrix. Complementary post-processing approach for quick detection and characterization were added to these filtered data.</p><p>The obtained results, which will be presented in detail at the conference, allowed us to state the imaging capabilities offered by the adopted instrumentation and obtain valuable information on the surveyed specimens, such as the corrosion thickness connection with apparent pseudo-intensity images. Finally, perspectives on coupling techniques will be introduced.</p><p><strong>Acknowledgments:</strong></p><p>Authors wish to thank Research Fund for Coal and Steel for funding part of this work under grant agreement No 800687 in the framework of DESDEMONA project.</p><p> </p><p><strong>References</strong></p><p>[1] A. Crinière, J. Dumoulin, C. Ibarra-Castanedo and X. Maldague ,” Inverse model for defect characterization of externally glued CFRP on reinforced concrete structures: Comparative study of square pulsed and pulsed thermography “, Quantitative InfraRed Thermography Journal, Taylor & Francis Editor, vol 11, pp 84-114, 2014. DOI: 10.1080/17686733.2014.897512.</p><p>[2] T. Sakagami, D. Shiozawa, Y. Tamaki, H. Ito A. Moriguchi, T. Iwama, K. Sekine and T. Shiomi, “Nondestructive detection of corrosion damage under corrosion protection coating using infrared thermography and terahertz imaging, in. Proc AITA 2015 conference, pp. 229-233, 2015.</p><p>[3] I. Catapano, F. Soldovieri, “A Data Processing Chain for Terahertz Imaging and Its Use in Artwork Diagnostics".J Infrared Milli Terahz Waves, pp.13, Nov. 2016.</p>

Data processing chain for high spatial resolution magnetic survey: Application on the Neolithic site of le Pontet (Charente-maritime, France)

2017 ◽  
Vol 25 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Guillaume Bruniaux ◽  
Vivien Mathé ◽  
François Lévêque ◽  
Adrien Camus ◽  
Vincent Ard
Keyword(s):  
Data Processing ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Magnetic Survey ◽  
Neolithic Site ◽  
Processing Chain

THz imaging in the frame of the Archaeological Urban Park of Naples project

2020 ◽  
Author(s):  
Ilaria Catapano ◽  
Carlo Noviello ◽  
Giovanni Ludeno
Keyword(s):  
Data Processing ◽  
Cultural Heritage ◽  
Time Domain ◽  
Imaging Techniques ◽  
Urban Park ◽  
Thz Imaging ◽  
Terahertz Waves ◽  
Non Invasive ◽  
Processing Chain ◽  
Molecular Stability

<p>The Archaeological Urban Park of Naples (PAUN) project aims at addressing the need of analytical information relating to cultural heritage with modalities that encourage innovation systems of protection and enhancement. In this frame, one of the specific goals is the testing of multiple non-invasive or only minimally invasive investigation techniques, aimed at identifying a permanent diagnostic system calibrated to the specific context of the Urban Archaeological Park of Piazza Municipio, Napoli, Italy.</p><p>Among the electromagnetic sensing technologies, those exploiting Terahertz waves (1THz = 10<sup>12</sup> Hz) are the newest among the imaging techniques, which offers the attractive chance of characterizing the inner features of manmade objects with a sub-millimeter spatial resolution in a non-invasive way while assuring negligible long-term risks to the molecular stability of the exposed objects.</p><p>This possibility together with the recent development of compact, transportable and easily reconfigurable devices make THz imaging a more and more widespread considered investigation tool in the frame of cultural heritage. THz imaging allows, indeed, the gaining of information useful to improve knowledge about the design technique adopted by the artist and to detect possible damages affecting the conservation state of precious artworks [1].</p><p>In the frame of PAUN project, THz imaging is considered as part of the sensor network, which is dedicated to the material characterization and supports the conservation and use of the assets of the Urban Archaeological Park of Piazza Municipio. Specifically, THz imaging is adopted to analyze ancient decorated mortar specimens and gather information on their stratigraphy. At this regard, it is worth pointing out that the effectiveness of THz imaging, i.e. the capability of obtaining high resolution images of the object under test, is dependent not only on the performances of the hardware technology but also on the data processing approaches. Herein, we consider the time domain Z-Omega Fiber-Coupled Terahertz Time Domain (FICO) system, which is available at IREA-CNR, and a data processing chain specifically designed to improve the discrimination of different material layers and to reconstruct the inner features characterizing the investigated artworks [2].</p><p> </p><p>[1] Fukunaga, THz Technology Applied to Cultural Heritage in Practice, Cultural Heritage Science, Springer.</p><p>[2] Catapano, I., Soldovieri, F. A Data Processing Chain for Terahertz Imaging and Its Use in Artwork Diagnostics. J Infrared Milli Terahz Waves 38, 518–530 (2017).</p><p> </p><p>Acknowledge: Authors would like to thank the PAUN project “Archaeological Urban Park of Naples” by which the present work has been financed.</p><p> </p>

Challenges in the Measurement and Data-Processing Chain of the LISA Mission

2009 ◽  
Vol 151 (1-3) ◽  
pp. 61-73 ◽  
Author(s):  
Peter F. Gath ◽  
Hans Reiner Schulte ◽  
Dennis Weise
Keyword(s):  
Data Processing ◽  
Processing Chain

scholarly journals Proposed standardized definitions for vertical resolution and uncertainty in the NDACC lidar ozone and temperature algorithms – Part 3: Temperature uncertainty budget

2016 ◽  
Author(s):  
Thierry Leblanc ◽  
Robert J. Sica ◽  
J. Anne E. van Gijsel ◽  
Alexander Haefele ◽  
Guillaume Payen ◽  
...  
Keyword(s):  
Data Processing ◽  
Cross Sections ◽  
A Priori ◽  
Uncertainty Budget ◽  
Standard Uncertainty ◽  
Atmospheric Composition ◽  
Mauna Loa ◽  
Processing Chain ◽  
Acceleration Of Gravity ◽  
The Individual

Abstract. A standardized approach for the definition, propagation and reporting of uncertainty in the temperature lidar data products contributing to the Network for the Detection for Atmospheric Composition Change (NDACC) database is proposed. One important aspect of the proposed approach is the ability to propagate all independent uncertainty components in parallel through the data processing chain. The individual uncertainty components are then combined together at the very last stage of processing to form the temperature combined standard uncertainty. The identified individual uncertainty components comprise signal detection uncertainty, uncertainty due to saturation correction, background noise extraction, the merging of multiple channels, the absorption cross-sections of ozone and NO2, the molecular extinction cross-sections, the a priori use of ancillary air, ozone, and NO2 number density, the a priori use of ancillary temperature to tie-on the top of the profile, the acceleration of gravity, and the molecular mass of air. The expression of the individual uncertainty components and their step-by-step propagation through the temperature data processing chain are thoroughly estimated. All sources of uncertainty except detection noise imply correlated terms in the vertical dimension, which means that covariance terms must be taken into account when vertical filtering is applied and when temperature is integrated form the top of the profile. Quantitatively, the uncertainty budget is presented in a generic form (i.e., as a function of instrument performance and wavelength), so that any NDACC temperature lidar investigator can easily estimate the expected impact of individual uncertainty components in the case of their own instrument. An example of a full uncertainty budget obtained from actual measurements by the JPL lidar at the Mauna Loa Observatory is also provided.

Sign in / Sign up

Export Citation Format

Share Document