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This paper investigates the feasibility of using the emission intensity of low‐pressure argon and nitrogen gas discharges as the sensing mechanism for a microwave electric field optical sensor probe in microwave resonant cavities. The emission is coupled to a photodiode for detection through an optical fibre due to the difficulty in using conventional optoelectronic devices in close proximity to microwave cavities. The discharge emission intensity is monitored at a range of different input powers to the cavity. The proposed designs for the electric field sensing probe are also included.

This paper aims to discuss the general principles behind the microwave sensing and demonstrates the potential of cavity microwave resonator device in real-time monitoring for: environmental monitoring with the focus on wastewater pollution, a system for oil/gas/water content evaluation in a dynamic pipeline, a system for real-time determination of bacteria concentration and a method for non-invasive glucose determination.

Microwave sensing is a rapidly developing technology which has been successfully used for various industrial applications including water level measurements, material moisture content, in construction industry for non-invasive evaluation of structures and even in the healthcare industry for non-invasive real-time monitoring of glucose in diabetic patients. Novel microwave cavities designed and tested for specific applications are presented.

The paper provides experimental results of testing the novel microwave sensing systems in a range of industrial and healthcare applications and discusses the potential of these systems for real-time monitoring of processes and parameters.

The concept of real-time microwave sensing was successfully tested, but further experiments are required to account for possible interference mechanisms before it can be used commercially on a large-scale.

It is suggested that a novel approach to wastewater monitoring, namely using specially designed microwave cavity sensors, could lead to a successful development of an advanced platform capable of providing for a real-time detection of water content with superior sensitivity. Also, a system for real-time multiphase fluid composition monitoring is reported, which is essential for sustainable oil industry operation.

The paper illustrated the potential of microwave sensing as a real-time monitoring platform for a broad spectrum of commercial applications, with a focus on system developed by the authors, namely, for the monitoring of a multiphase fluid flow in a dynamic oil pipeline, for real-time monitoring of nutrients concentration in wastewater and for healthcare industry, in particular for real-time non-invasive determination of the glucose levels and bacteria concentration.

The purpose of this paper is to provide a detailed review of radiation dosimetry techniques based on optical fibre dosimeters. It presents a comprehensive bibliography of the current research activities in the area.

A range of published work on optical fibre radiation dosimeters are presented, with the merits and limitations discussed. Each radiation dosimetry technique is discussed in turn, providing examples of dosimeters using such techniques reviewed. The main focus is on gamma radiation although other radiation dosimeters are considered.

This paper provides information on the wide range of research activity into radiation dosimeters. The dose ranges of these dosimeters are presented, along with the advantages and disadvantages of different dosimetry techniques.

A comprehensive review of published research in the area of solid radiation dosimetry is presented in this paper. It provides an individual with a review of the various techniques used and most recent research in that field.

Utilization of electromagnetic wave (EMW) sensors in an underwater environment has the potential to increase the data rate compared to acoustic-based sensors because of the ability to use larger signal bandwidth. Nevertheless, EMW signals has the drawback of large signal attenuation in underwater, attributed to the high relative permittivity and conductivity of water compared to the atmosphere, hence employment of wide signal bandwidth is necessary to balance the data rate-attenuation trade-off. The purpose of this paper is to analyze the characteristics of both narrowband and wideband EMW signal propagation underwater and devise a path loss model for both cases.

Path loss measurement was conducted using a point-to-point configuration in a laboratory water tank while transmitting narrowband and wideband signals between a pair of wideband underwater antennas. The wideband underwater antennas use buffer-layer structures as the impedance matching layer to optimize the antenna performance when operating underwater. The path loss for narrowband signal was modeled using a multi-layer propagation equation in lossy medium considering losses at the medium boundaries. For the case of the wideband signal, a modified version of the model introducing power integration over bandwidth is adopted. These models were formulated through numerical simulations and verified by measurements.

The measured narrowband path loss marked an 80 dB attenuation using 800 MHz at 2 m distance. The proposed narrowband model agrees well with the measurements, with approximately 3 dB modeling error. Utilization of the proposed wideband path loss model resulted in a reduction of the gradient of the path loss curve compared to the case of the narrowband signal. The measured wideband path loss at 2 m distance underwater was approximately −65 dB, which has been shown to enable a working signal-to-noise ratio of 15 dB. This proves the potential of realizing high data rate transmission using the wideband signal.

The paper proposed a wideband propagation model for an underwater EMW sensor network, using power integration over bandwidth. The effectiveness of using wideband EMW signals in reducing path loss is highlighted, which is seldom discussed in the literature. This result will be of useful reference for using wideband signals in designing a high data rate transmission system in underwater wireless sensor networks, for example, in link budget, performance estimation and parameter design of suitable transmission scheme.

Image‐based localisation has been widely investigated in mobile robotics. However, traditional image‐based localisation approaches do not work when the environment appearance changes. The purpose of this paper is to propose a new system for image‐based localisation, which enables the approach to work also in highly dynamic environments.

The proposed technique is based on the use of a distributed vision system (DVS) composed of a set of cameras installed in the environment and of a camera mounted on a mobile robot. The localisation of the robot is achieved by comparing the current image grabbed by the robot with the images grabbed, at the same time, by the DVS. Finding the DVS's image, most similar to the robot's image, gives a topological localisation of the robot.

Experiments reported in the paper proved the system to be effective, even exploiting a pre‐existent DVS not designed for this application.

Whilst, aware that DVSs, as the one used in this work, are not diffuse nowadays, this work is significant because a novel idea is proposed for dealing with dynamic environments in the image‐based localisation approach and the idea is validated with experiments. Camera Sensor networks currently are an emerging technology and they may be introduced in several daily environments in the future.

The purpose of this paper is to look at fibreoptic sensing techniques and applications.

The paper provides information on fibreoptic sensing technologies, instrumentation, advantages and applications.

Fibreoptic sensing, especially fibreoptic Bragg gratings, provide a highly effective means of monitoring internal changes in structural and other components that were previously impossible or very difficult to detect. Such systems are now approaching full commercialisation.

The paper provides a useful overview of how fibreoptic sensors work, and the advantages they provide when used in instrumentation applications ranging from compact devices to large and complex structures, where they may be structurally integrated.

The purpose of this paper is to examine existing radar sensor results, techniques for through‐wall radar and current applications for the technology.

The paper provides information on sensing through a high‐attenuation obstacle and the associated pitfalls and considerations. Results from ultra‐wide‐band (UWB) impulse radar, micro‐Doppler radar, and synthetic aperture radar (SAR) targeted at this area are presented. Discussion of radar clutter classification is given and also observations on presenting a system with a non‐zero false alarm rate to a user to give best confidence and maximum decision capability.

There are significant new requirements for through‐wall radar which a combination of UWB, continuous wave, and SAR techniques with recent signal processing advances and the advent of low‐cost radio and image processing can meet in distributed markets. Risk of a poor user level decision in a non‐zero‐false‐alarm‐rate system can be mitigated by increasing the number of inputs into the decision.

The paper lists challenges that have been overcome in the area of through‐wall sensing and presents results from novel radar sensors.

The purpose of this paper is to provide a review of the industrial sensing applications of electromagnetic radiation (EMR) with an emphasis on wavelengths other than visible light. The paper is in two parts. This, the first, considers radiations with shorter wavelengths than visible light, i.e. γ radiation, X‐rays and ultra‐violet (UV).

The paper discusses the sensing applications of short wavelength EMR through reference to the techniques employed, products and their uses.

The paper shows that γ radiation, X‐rays and UV radiation are used in a wide range of industrial sensors for the measurement of physical variables, chemical compounds and gases. The phenomena employed include absorption, backscatter, photoionisation, fluorescence and reflection. Applications are extremely varied and embrace a diversity of industries.

The paper provides a detailed, technical review of the sensing uses of short wavelength EMR.

The purpose of this paper is to provide a brief review of sensing with neutrons.

The paper discusses neutron sources, sensing techniques and a number of established and emerging applications.

The paper shows that neutron‐based sensing is used to determine a range of physical and chemical variables in the process, minerals, chemicals, security and military industries.

The paper provides a concise overview of the technology and uses of neutron‐based sensing.

The purpose of this paper is to present improvements in X‐ray equipment, which are leading to wider use.

Developments in X‐ray sources and detectors are described. This is followed by a review of the more innovative equipment available for security and industrial applications.

Technological developments have produced smaller, lighter X‐ray systems and extended their applications to on‐site work. Multiple wavelength systems distinguish between different materials, and stereo systems remove ambiguities from X‐ray security imaging and allow 3D gauging of industrial components.

The paper highlights the availability of portable X‐ray systems and explains the underlying technology.