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In this paper, a functional model for determining the minimum and maximum detectable deformation gradient in terms of coherence for synthetic aperture radar (SAR) sensors is presented. The model is developed based on a new methodology that incorporates both real and simulated data. Sets of representative surface deformation models have been simulated, and the associated phase from these models introduced into real SAR data acquired by European Remote Sensing 1 and 2 satellites. Subsequently, interferograms were derived, and surface deformation was estimated. A number of cases of surface deformation with varying magnitudes and spatial extent have been simulated. In each case, the resultant surface deformation has been compared with the 'true' surface deformation as defined by the deformation model. Based on these comparisons, a set of observations that lead to a new functional model has been established. Finally, the proposed model has been validated against external datasets and proven viable. Although the major weakness of the model is its reliance on visual interpretation of interferograms, this model can serve as a decision-support tool to determine whether or not to apply satellite radar interferometry to study a given surface deformation. Index Terms--Coherence, deformation, European Remote Sensing (ERS) satellite, interferometric synthetic aperture radar (InSAR), radar interferometry.

We present a modification to the adaptive Goldstein radar interferogram filter which improves the quality of interferometry products. The proposed approach makes the Goldstein filter parameter alpha dependent on coherence, such that incoherent areas are filtered more than coherent areas. This modification minimizes loss of signal while still reducing the level of noise. Index Terms--Phase filtering, phase statistics, radar interferometry, synthetic aperture radar (SAR).

When crude oil is stored in large tanks, invariably high-molecular-weight organic sediments (paraffin) are deposited but the resulting sediments contains also solid particles (sand, silt, corrosion products, etc.) and also water. After some period of in-service of tank, these deposits build up to form a sludge, which causes a reduction in the storage capacity. These high in hydrocarbons a valuable raw material could be proper recovered and recycled back to the refining process. Therefore, it is significant to know the sludge characteristics shape and volume to define the best form of treatment (maintenance of tank for control of level of sludge) and removal method (in case of out of service and opening of tank). The knowledge about volume and shape of such sludge inside tanks is important for user of tank farm due to a reasons such as: maintenance of storage tanks and control/monitoring of level of sludge inside them, when conventional treatments are used to remove crude oil sludge, there is a potential for high environmental impact, so the choose of the method of cleaning is very essential, most of design of tanks is with floating roofs, what in case when inside tank is high level of sludge could cause problems and/or damage of roof for low level stored product. In this paper are presented AE and thermography techniques for assess of level, volume and shape of sludge inside storage tank. Thermography method is used to assess the level of sludge (heights) along the storage tank shell. AE technique is used in this case in different way than normally purposes. There is used specific layout of sensors on the wall and roof of the tank. The sensors generate of AE pulses according to established algorithm, which allows to record AE signals were caused the waves propagation and waves reflection (including from sludge) in storage product between sensors. Under measured differences in time of wave propagation are evaluated heights of sludge in various points inside on the bottom of tank. In 2017 Office of Technical Inspection (UDT) opened the project to develop a system for assessing of the level, volume and shape of sludge inside crude oil storage tanks, using AE technique and thermography. As part of the project, UDT has started cooperation with company PERN S.A. the national and regional leader in oil logistics. [ABSTRACT FROM AUTHOR]

Considerable quantity of underground in-plant pipelines of crude oil of fuel storage depots and refineries is operated for more than thirty years. Corrosion damages and material degradation are the main causes for structural failures of such underground pipelines. Such failures not detected on time and not monitored in time are potentially the reasons of major breakdowns of the infrastructure of technological underground pipeline installations in-service and finally are the risks of pollution of the environment. The preventive maintenance activities are usually carried out on time driven basis, but evolving defects have to be identified in time to enable appropriate repairs. The primary disadvantages are limited access to pipelines and limited possibilities of testing, due to the necessity for off-line pressure tests of a big part of underground pipeline installation, possible visual inspection and follow-up non-destructive tests (NDT). Based on these facts, we conducted investigations for application of AE testing method of underground pipelines during pressure tests using liquid product transported through pipe. We present the AE investigation on pipeline materials and on real underground pipelines. [ABSTRACT FROM AUTHOR]

Currently a significant part of operated railway steel bridges in Poland is exploited from the beginning of XX-th century. Very often the technical condition of them is bad and these objects require the appropriate diagnostics. Mostly the visual diagnostics is used, and in exceptional cases in some places of objects the other non-destructive testing are performed. Therefore the opinion about condition of bridge is non completed and it is necessary to study the effective method, which will enable on more exact diagnostics of steel bridges. The Cracow University of Technology together with PKP Polish Railway Lines realizing the project for the work out of diagnostic method the steel railway bridges with use of acoustic emission method (AE). During project realization, the laboratory tests on material from railway steel bridge for collection data were performed. These measurements were done on standard specimens and on samples with corrosion products. The AE measurements on real object with different crack size were also done. The tests were carried out at a controlled moving train at different speeds and for various weight of railway carriages. The results of acoustic emission tests and analysis with standard and additional parameters are presented. The results of metallography and numerical analysis of bridge and defected element are also presented. [ABSTRACT FROM AUTHOR]

Acoustic Emission was applied to detect microcrack initiation in unidirectional (1D) carbon fiber reinforced composites (CFRP) subjected to 4-point bending. Materials were prepared from polyester (PES) bonded 1D carbon fiber fabric and epoxy resin using the RTM technology. Fiber volume content of composites varied from small (35%) through medium (51%) to high (68%). Samples were cut from 1D composite plates to the size of 120x20x2mm in two orthogonal directions - along fibers [0] and across fibers [90]. Selected samples had part of their tensile surface (in bending) pre-polished to enable microscopic (SEM) observations. Samples were subjected to monotonic and step-loading tests in 4-point bending while Acoustic Emission (AE) sensors attached to samples' surfaces monitored the damage initiation. The AE Historic Index proved to be the most reliable AE parameter indicating damage initiation, which allowed to interrupt loading sequence before failure. Details of microcracks were observed under the SEM on polished composite tensile surfaces loaded in bending. Fiber debonding and breakage occurred simultaneously and were the first defects to initiate damage in the examined materials. [ABSTRACT FROM AUTHOR]

The paper describes the examples of AE method in industry for detecting and locating leaks in constructions of double bottom storage tanks. The tests were made on new and modernized tanks in various test conditions and utilized different ways of defect location. It presents also results of laboratory tests to evaluate the possibility of detecting corrosion processes in this inaccessible space of double bottom. [ABSTRACT FROM AUTHOR]