Estimation of Leaf Thickness with Remote Sensing

2012 ◽  
Vol 263-266 ◽  
pp. 339-345 ◽  
Author(s):  
Xue Yan Sui ◽  
Xiaodong Zhang ◽  
Yong Wang ◽  
Shao Kun Li
Keyword(s):  
Remote Sensing ◽  
Real Time ◽  
Regression Models ◽  
Leaf Thickness ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Important Index ◽  
Growing Conditions ◽  
Set Up ◽  
Non Destructive

Leaf thickness is one important index of describing plant growing conditions. But the measurements now are all tedious and destructive. In order to carry out real-time, live, non-destructive testing of leaf thickness, the study took cotton leaves as the research object. The correlations of leaf thickness with reflectance, vegetable index and spectral figure index were analyzed separately. And then the cause of correlation was studied. Three regression models were set up with the 3 parameters which had high correlation with leaf thickness. Among these models, the highest relative error is 7.4%, and the RMSE is 0.051 mm. It is feasible to measure alive leaf thickness untouchably with Hyper spectrum.

Non-Destructive Testing of Mass Produced Components by Natural Frequency Measurements

1985 ◽  
Vol 199 (3) ◽  
pp. 161-168 ◽  
Author(s):  
P Cawley
Keyword(s):  
Natural Frequencies ◽  
Production Quality ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Production Quality Control ◽  
Cross Sectional ◽  
Dimensional Changes ◽  
Single Section ◽  
Set Up ◽  
Non Destructive

Vibrations in engineering components may be excited by a light tap and the vibration response may be measured with a microphone and displayed as a frequency spectrum from which the natural frequencies of the component can be extracted. Changes in the natural frequencies of the various modes are observed when small defects such as cracks are present. The use of this technique for the production quality control of mass produced components has been investigated. Tests have been carried out on a cantilever beam, a piston-shaped component and a pulley wheel. It has been shown that, in the absence of dimensional variations, defects removing between 0.5 and 2 per cent of the cross-sectional area of the component at a single section may be detected, the precise size depending on the geometry of the component and the location of the defect. Dimensional variations reduce this sensitivity, but a method has been developed for correcting the results for dimensional changes, without the need for more measurements to be taken. The results show that, unless the likely location of a defect is known in advance, it is essential to measure the natural frequencies of more than one mode of vibration. The test takes less than ten seconds to set up, about one second to carry out and is amenable to automation.

scholarly journals Non-destructive investigation of polymer-metal bonds using a VibroMap1000 holographic vibrometer

2019 ◽  
Vol 299 ◽  
pp. 04010
Author(s):  
Zawadzki Pawel ◽  
Meijer Frans ◽  
Stachowska Ewa ◽  
Legutko Stanisław
Keyword(s):  
Processing System ◽  
Accurate Assessment ◽  
Non Destructive Testing ◽  
Data Processing System ◽  
Destructive Testing ◽  
Frequency Scanning ◽  
Polymer Metal ◽  
Set Up ◽  
Non Destructive ◽  
Metal Bonds

We developed a method to test polymer-metal bonds using a VibroMap1000 holographic vibrometer. The set-up and the data processing system allow non-destructive testing of polymer-metal bonds for samples of a specific size and structure. Frequency scanning from 200 Hz - 20 kHz provides characteristics of the sample. Because the method is non-destructive the sample can be studied afterwards with other methods too. These combined with the measurements of the holographic vibrometer, can create a complete and accurate assessment of the state of polymer-metal bonds. We present some preliminary results.

Optical coherence tomography for non-destructive testing

2020 ◽  
Vol 87 (6) ◽  
pp. 404-413
Author(s):  
Fabian Zechel ◽  
Rouwen Kunze ◽  
Niels König ◽  
Robert Heinrich Schmitt
Keyword(s):  
Optical Coherence Tomography ◽  
Real Time ◽  
Optical Method ◽  
Review Paper ◽  
Optical Coherence ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Non Destructive ◽  
Time Evaluation ◽  
Penetration Depths

AbstractIn this review paper, conventional non-destructive testing (NDT) methods are briefly introduced and compared with selected examples for applications of optical coherence tomography (OCT) for NDT. The contactless, non-destructive and purely optical method enables multi-dimensional imaging for tomographic real-time evaluation in various fields of application. Depending on the material, penetration depths of several millimeters can be achieved, thus providing an attractive solution that can be used both as a stand-alone and as a process-integrated solution.

scholarly journals A Digital Grayscale Generation Equipment for Image Display Standardization

2020 ◽  
Vol 10 (7) ◽  
pp. 2297
Author(s):  
Yiqin Jiang ◽  
Zilong Liu ◽  
Yuxiao Li ◽  
Jin Li ◽  
Yusheng Lian ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Accuracy ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Digital Light Processing ◽  
Time Frequency ◽  
Relative Value ◽  
The Relationship ◽  
Non Destructive ◽  
Digital Equipment

The standardization of grayscale display is essentially significant for image signal communication, transmission, and terminal reading. The key step of this standardization is establishing a traceable equipment of grayscale. As a relative value, grayscale is transferred to two different absolute values to satisfy different traceability methods, including optical density for hardcopy image and luminance for softcopy. For luminance, a generation equipment is designed to build the relationship between luminance and grayscale. In this work, novel equipment is established using digital light processing (DLP) by time-frequency modulation, and the corresponding uncertainty is analyzed. The experiment result shows that this digital equipment builds the relationship between grayscale and luminance in the range of 0.16-4000 cd/m2. It enables traceable measurement of grayscale to luminance on this equipment with high accuracy and can provide a standardized reference for the display of grayscale images in the fields of medicine, remote sensing, non-destructive testing, etc.

scholarly journals Design and Development of Aircraft Propeller Maintenance Facility for General Aviation

Khazanah ◽  
2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Amman Mujahid ◽  
Keyword(s):  
Environmental Impact ◽  
Visual Inspection ◽  
General Aviation ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Proactive Approach ◽  
Maintenance Techniques ◽  
Set Up ◽  
Environment Sustainability ◽  
Non Destructive

Since the first flight and introduction of propellers from marine to the sky, various maintenance techniques have been employed to maintain aircraft propellers. With the advancement in the operation and safety of flight, propellers have been manufactured in various materials, shapes and measurements. The design developed is based on the concept of a “single stop shop facility”. The propeller maintenance facility majorly focuses the general aviation in order to provide them a set up that primarily focuses on the maintenance of propellers in order to avoid malfunctions resulting in accidents and failures. The maintenance procedures for workbench include static balancing, blade tracking, cleaning, visual inspection, corrosion removal and Non-Destructive Testing (NDT). The developed facility has an accelerated scalability with the provision of facilitating Non-Destructive Testing that is performed on the workbench. The non-destructive testing results in assuring reliability and safety of the propellers as per the modern maintenance practices. The workbench developed focuses over the environment sustainability as it functions on the concept of sustainable maintenance that involves reduced unnecessary maintenance. Moreover, the currently developed facility integrates a proactive approach involving reduced use of energy in order to produce less waste and environmental impact. At present, the workbench has been manufactured and is being tested for propeller maintenance procedures.

scholarly journals Algorithms for searching defects in engineering structures using GPR (Review article, Part I)

2019 ◽  
Keyword(s):  
Remote Sensing ◽  
Polarization State ◽  
Layered Media ◽  
Ultra Wideband ◽  
Primary Data ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Engineering Structures ◽  
Wide Range ◽  
Non Destructive

Relevance of the problem of the development of technical means (GPR) and algorithms for processing ultra-wideband signals follows from the wide range of possibilities that these means of non-destructive testing and remote sensing provides, together with the potential of modern computing tools and software. Of particular interest in this regard are the results obtained by using various effects associated with a change in the polarization state of both primary (probing) pulses and signals reflected from complex multilayer media to detect defects in them. This is due to the possibility of not only quickly detecting heterogeneities, but also with the relatively low cost of such work. The purpose of the work is a review of various technical means (pulsed georadars) and signal processing methods for detecting various internal inhomogeneities in plane-layered media. These heterogeneities include, in addition to various internal communications elements (cables) and technical elements (drainage pipes), also dangerous externally invisible defects - subsurface cracks and delamination (interruption of contact between the layers). Materials and methods. The paper provides an overview of methods developed by the author, among others, which are designed to solve primarily the practical problems of detecting subsurface inhomogeneities and defects in plane-layered media. The physical basis for the creation of these methods was the result of many years of research by the author related to the analysis of the polarization state of complex (including pulsed) signals scattered by various objects. Results. The basis of the considered results is made up of both scientific articles and patents of Ukraine for inventions and utility models obtained by the author. Conclusions. The review of the results and various methods presented in the article is another confirmation of the wide possibilities offered by new means of remote sensing and non-destructive testing. These tools include not only the devices themselves (elements for obtaining primary data), but also information processing algorithms and software, combined into a single methodology for collecting, processing and subsequent storage of data on the current state of the examined technical and natural objects.

scholarly journals A Versatile Illumination System for Real-Time Terahertz Imaging

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3993
Author(s):  
Jean-Baptiste Perraud ◽  
Adrien Chopard ◽  
Jean-Paul Guillet ◽  
Pierre Gellie ◽  
Antoine Vuillot ◽  
...  
Keyword(s):  
Real Time ◽  
Signal To Noise Ratio ◽  
Beam Steering ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Full Field ◽  
Illumination System ◽  
Optimized Distribution ◽  
Non Destructive ◽  
Field Imaging

Terahertz technologies are attracting strong interest from high-end industrial fields, and particularly for non-destructive-testing purposes. Currently lacking compactness, integrability as well as adaptability for those implementations, the development and commercialisation of more efficient sources and detectors progressively ensure the transition toward applicative implementations, especially for real-time full-field imaging. In this work, a flexible illumination system, based on fast beam steering has been developed and characterized. Its primary goal is to suppress interferences induced by the coherence length of certain terahertz sources, spoiling terahertz images. The second goal is to ensure an enhanced signal-to-noise ratio on the detector side by the full use and optimized distribution of the available power. This system provides a homogeneous and adjustable illumination through a simplified setup to guarantee optimum real-time imaging capabilities, tailored to the sample under inspection. Working toward industrial implementations, different illumination process are conveniently assessed as a result of the versatility of this method.

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