Novel Atmospheric Monitoring for the H.E.S.S. site and its Industrial Applications

This thesis concerns the atmospheric monitoring instrumentation for the H.E.S.S. (High Energy Stereoscopic System) gamma-ray telescope site and the adaptation of such instruments for commercial use. The effect of the atmosphere on the H.E.S.S. telescopes' response has been demonstrated and the technicalities associated with the atmospheric monitoring instruments have been studied in depth. The responses of a LIDAR (Light Detection And Ranging) and a transmissometer have been checked by customised MODTRAN (MODerate resolution atmospheric TRANsmission) routines. This process revealed a malfunction of the LIDAR, whose raw data was independently treated to yield meaningful results. More importantly, the `Durham-designed' transmissometer, manufactured to operate during the night in parallel with the H.E.S.S. telescopes, was successfully adapted for day-light operation. As a result Durham prototype gained strong interest from Aeronautical & General Instruments Limited (AGI) in Dorset, who are particularly interested in the airport applications, and see the Durham instrument as a potential replacement for the transmissometer which they manufacture currently and is coming to the end of its useful design life. Durham University and AGI drew up a license agreement to pursue further development of the instrument. The resulting Durham aviation transmissometer meets the accuracy requirements for the Runway Visual Range (RVR) assessment imposed by both the World Meteorological Organisation (WMO) and the International Civil Aviation Organisation (ICAO). Moreover, the Durham instrument is easy to align, uses very little power, and is lightweight and portable, enabling its use not only in civil airports, at altitudes exceeding all prior-art aviation transmissometers, but also in tactical military applications, such as remote landing strips

The occurrence and origin of salinity in non-coastal groundwater in the Waikato region

Aims The aims of this project are to describe the occurrence, and determine the origin of non-coastal saline groundwater in the Waikato region. High salinity limits the use of the water for supply and agricultural use. Understanding the origin and distribution of non-coastal salinity will assist with development and management of groundwater resources in the Waikato. Method The occurrence of non-coastal groundwater salinity was investigated by examining driller’s records and regional council groundwater quality information. Selected wells were sampled for water quality analyses and temperatures were profiled where possible. Water quality analyses include halogens such as chloride, fluoride, iodide and bromide. Ratios of these ions are useful to differentiate between geothermal and seawater origins of salinity (Hem, 1992). Other ionic ratio approaches for differentiating sources and influences on salinity such as those developed by Alcala and Emilio (2008) and Sanchez-Martos et al., (2002), may also be applied. Potential sources of salinity include seawater, connate water, geothermal and anthropogenic influences. The hydrogeologic settings of saline occurrence were also investigated, to explore the potential to predict further occurrence. Results Numerous occurrences of non-coastal saline groundwater have been observed in the Waikato region. Where possible, wells with relatively high total dissolved solids (TDS) were selected for further investigation. Several groundwater samples are moderately saline and exceed the TDS drinking water aesthetic guideline of 1,000 g m-3 (Ministry of Health, 2008). Selected ion ratios (predominantly halogens) were used to assist in differentiating between influences on salinity such as seawater and geothermal. Bromide to iodide ratios, in particular, infer a greater geothermal influence on salinity, although other ratios are not definitive. The anomalously elevated salinity observed appears natural but nevertheless has constrained localised groundwater resource development for dairy factory, industrial and prison water supply use. Further work may show some relationship with geology or tectonics, which could assist prediction of inland saline groundwater occurrence

Exploring Beijing's urban environment: air quality, haze effects and climate

Towards the end of the last century, significant increases in coal burning for electricity at power plants and for domestic heating purposes led to rapid increases in the levels of harmful gaseous and particulate pollutants in the atmosphere over urban areas in China. The concurrent rise in urban populations has resulted in an ever-increasing human health risk associated with the inhalation of ambient air pollution. Most notably, long- and short-term exposure to PM2.5, describing fine particles suspended in the atmosphere with a diameter ≤ 2.5 μm, is the fourth leading cause of premature death in China. Additionally, very high ambient concentrations of PM2.5 characterising haze pollution events can block a large fraction of incoming sunlight, impacting atmospheric chemistry and reducing heating of the urban surface which drives the mixing of near-surface air. Both of these effects can substantially impact urban air quality. Development of urban areas is also associated with the replacement of vegetative, rural surfaces with urban materials (e.g. concrete). This increases the amount of sunlight absorbed at the ground, reduces cooling associated with evaporation, and thus urban air temperatures are higher than adjacent rural areas. Heat released by human activities (anthropogenic heat) directly into the atmosphere further strengthens the urban -rural temperature contrast (known as the urban heat island). Extreme urban air temperatures, particularly in summer, reduce human thermal comfort and increase the heat-related mortality risk. The main objectives of this study are to (a) quantify the air pollution levels in Beijing in winter at street-scale resolution and understand the key influencing processes, (b) quantify the effects of haze-sunlight interactions on Beijing’s air quality in winter, and (c) understand the relative importance of urban materials and anthropogenic heat emissions in forming Beijing’s urban heat island in winter and summer. For the air quality-related objectives of this work, we use a computer-based model (ADMS-Urban) that replicates the release of air pollutants from a range of activities in urban areas, and accounts for the effects of local weather and chemical reactions on air pollution levels. The ADMS-Urban model can estimate air pollution level variations across very fine spatial extents (< 10 m). Comparisons between modelled and measured air pollutant concentrations inform on the model performance, revealing the success of our model configuration and whether further adjustments are required. To study Beijing’s climate, we use a recently developed variation of the ADMS-Urban model, the ADMS-Urban Temperature and Humidity model (ADMS-UHI). ADMS-UHI is used to calculate air temperature variations across neighbourhood extents (~ 100 m) due to surface thermal characteristics and anthropogenic heat release. The air quality model simulations require estimates of emission rates from roads. For this, we share emissions estimated at grid-level (3 km) resolutions across individual road sections; major roads (e.g. motorway) are apportioned more than minor roads (e.g. residential). Measured air pollutant concentrations are much higher than modelled levels at night, suggesting the emissions estimates are missing a significant evening source; this is most likely related to heavy duty diesel trucks that enter the city at night when travel restrictions are lifted. The model cannot replicate the measured PM2.5 spatial variability. This is likely due to the exclusion of emissions from explicitly represented point sources (e.g. large industry) in the model configuration due to a lack of information on their locations. Also, we assume background air pollutant levels are uniform across Beijing, which is unlikely across such a large urban area. Overall, the measured-modelled air pollutant concentration agreement is strong, indicating that the methodologies and materials implemented for this study can be successfully applied to urban areas elsewhere to help guide air pollution control policies. According to a number of previous modelling studies across China, haze-sunlight interactions have substantial effects on urban air quality. Therefore, to improve the accuracy of urban air quality assessments with ADMS-Urban across polluted megacities such as Beijing, the model, which currently does not account for the impacts of haze, should be adjusted accordingly. Therefore, we alter the modelled air pollution dispersion and chemistry processes to account for reduced sunlight reaching the surface on haze days and analyse the impacts on simulated near-surface air quality. Reduced surface heating on haze days suppresses the vertical mixing of air and therefore increases the modelled concentrations of primary air pollutants such as nitrogen oxides (NOx = NO + NO2). However, near-surface levels of the secondary air pollutant species O₃ reduces substantially due to (a) increased removal from reactions with NO, and (b) suppressed formation via sunlight interactions with NO₂. Measured-modelled O₃ agreement improves significantly when haze effects are considered. The final objective of this thesis is explored with ADMS-UHI. During the winter, the impact of anthropogenic heat emissions on the UHI far outweighs the effects of urban surface thermal properties. UHI intensities (urban-rural temperature difference) are much greater at night than during the day in both winter and summer. In summer, this is mostly related to the evening release of heat stored in the urban fabric throughout the day. Negative daytime UHI intensities in summer highlight the cooling effect of urban green space. Overall, this study provides useful information for urban planners aiming to reduce heat-related health risks across complex urban areas such as Beijing

Earth imaging with microsatellites: An investigation, design, implementation and in-orbit demonstration of electronic imaging systems for earth observation on-board low-cost microsatellites.

This research programme has studied the possibilities and difficulties of using 50 kg microsatellites to perform remote imaging of the Earth. The design constraints of these missions are quite different to those encountered in larger, conventional spacecraft. While the main attractions of microsatellites are low cost and fast response times, they present the following key limitations: Payload mass under 5 kg, Continuous payload power under 5 Watts, peak power up to 15 Watts, Narrow communications bandwidths (9.6 / 38.4 kbps), Attitude control to within 5&deg;, No moving mechanics. The most significant factor is the limited attitude stability. Without sub-degree attitude control, conventional scanning imaging systems cannot preserve scene geometry, and are therefore poorly suited to current microsatellite capabilities. The foremost conclusion of this thesis is that electronic cameras, which capture entire scenes in a single operation, must be used to overcome the effects of the satellite's motion. The potential applications of electronic cameras, including microsatellite remote sensing, have erupted with the recent availability of high sensitivity field-array CCD (charge-coupled device) image sensors. The research programme has established suitable techniques and architectures necessary for CCD sensors, cameras and entire imaging systems to fulfil scientific/commercial remote sensing despite the difficult conditions on microsatellites. The author has refined these theories by designing, building and exploiting in-orbit five generations of electronic cameras. The major objective of meteorological scale imaging was conclusively demonstrated by the Earth imaging camera flown on the UoSAT-5 spacecraft in 1991. Improved cameras have since been carried by the KITSAT-1 (1992) and PoSAT-1 (1993) microsatellites. PoSAT-1 also flies a medium resolution camera (200 metres) which (despite complete success) has highlighted certain limitations of microsatellites for high resolution remote sensing. A reworked, and extensively modularised, design has been developed for the four camera systems deployed on the FASat-Alfa mission (1995). Based on the success of these missions, this thesis presents many recommendations for the design of microsatellite imaging systems. The novelty of this research programme has been the principle of designing practical camera systems to fit on an existing, highly restrictive, satellite platform, rather than conceiving a fictitious small satellite to support a high performance scanning imager. This pragmatic approach has resulted in the first incontestable demonstrations of the feasibility of remote sensing of the Earth from inexpensive microsatellites

Proceedings of the European Conference on Agricultural Engineering AgEng2021

This proceedings book results from the AgEng2021 Agricultural Engineering Conference under auspices of the European Society of Agricultural Engineers, held in an online format based on the University of Évora, Portugal, from 4 to 8 July 2021. This book contains the full papers of a selection of abstracts that were the base for the oral presentations and posters presented at the conference. Presentations were distributed in eleven thematic areas: Artificial Intelligence, data processing and management; Automation, robotics and sensor technology; Circular Economy; Education and Rural development; Energy and bioenergy; Integrated and sustainable Farming systems; New application technologies and mechanisation; Post-harvest technologies; Smart farming / Precision agriculture; Soil, land and water engineering; Sustainable production in Farm buildings

Handbook of Vascular Biometrics

This open access handbook provides the first comprehensive overview of biometrics exploiting the shape of human blood vessels for biometric recognition, i.e. vascular biometrics, including finger vein recognition, hand/palm vein recognition, retina recognition, and sclera recognition. After an introductory chapter summarizing the state of the art in and availability of commercial systems and open datasets/open source software, individual chapters focus on specific aspects of one of the biometric modalities, including questions of usability, security, and privacy. The book features contributions from both academia and major industrial manufacturers

Full Proceedings, 2018

Full conference proceedings for the 2018 International Building Physics Association Conference hosted at Syracuse University

Polarimetric Synthetic Aperture Radar

This open access book focuses on the practical application of electromagnetic polarimetry principles in Earth remote sensing with an educational purpose. In the last decade, the operations from fully polarimetric synthetic aperture radar such as the Japanese ALOS/PalSAR, the Canadian Radarsat-2 and the German TerraSAR-X and their easy data access for scientific use have developed further the research and data applications at L,C and X band. As a consequence, the wider distribution of polarimetric data sets across the remote sensing community boosted activity and development in polarimetric SAR applications, also in view of future missions. Numerous experiments with real data from spaceborne platforms are shown, with the aim of giving an up-to-date and complete treatment of the unique benefits of fully polarimetric synthetic aperture radar data in five different domains: forest, agriculture, cryosphere, urban and oceans

Eighth International Workshop on Laser Ranging Instrumentation

The Eighth International Workshop for Laser Ranging Instrumentation was held in Annapolis, Maryland in May 1992, and was sponsored by the NASA Goddard Space Flight Center in Greenbelt, Maryland. The workshop is held once every 2 to 3 years under differing institutional sponsorship and provides a forum for participants to exchange information on the latest developments in satellite and lunar laser ranging hardware, software, science applications, and data analysis techniques. The satellite laser ranging (SLR) technique provides sub-centimeter precision range measurements to artificial satellites and the Moon. The data has application to a wide range of Earth and lunar science issues including precise orbit determination, terrestrial reference frames, geodesy, geodynamics, oceanography, time transfer, lunar dynamics, gravity and relativity