To see the other types of publications on this topic, follow the link: In situ sensing.
Dissertations / Theses on the topic 'In situ sensing'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'In situ sensing.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Xu, Lu M. Eng Massachusetts Institute of Technology. "An improved in situ sensing device for freshwater DOM characterization." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104251.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 27-28).
DOC characterization of freshwater is poorly understood at areas of harsh or difficult to access, especially areas like peatland rainforest. In order to figure out the level of DOC transport, an in situ instrument was previously designed to measure the DOC concentration at remote locations. However, the data collected by the instrument is not as meaningful as expected due to the complex environment, high DOC concentration and inner shielding. A new instrument is required to be designed to fulfil the objectives. Like the previous instrument, the new instrument still needs to measure the fluorescence and absorbance data to give an estimation of DOC concentration. There are three LEDs to provide fluorescence measurements, a wideband lamp to provide light for absorbance measurement and a spectrometer to record the resulting spectra. Unlike general in situ fluorometers, the orientation between the excitation source and detector is 90 degrees for the new optical configuration. The new designed optical configuration solves the problem of window obstruction and also successfully prevents the problem of misalignment caused by water turbulence. Furthermore, the instrument also solves the problem of long light path lengths with the new configuration. The instrument was tested to work well in the lab with a range of DOC concentration from 5 ppm to 60 ppm. The recorded data showed a strong positive relationship between fluorescence intensity and concentration of DOC.
by Lu Xu.
M. Eng.
2
Mtshemla, Kanyisa Sipho. "Mission design of a CubeSat constellation for in-situ monitoring applications." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2633.
Full textAbstract:
Thesis (MEng (Electrical Engineering))--Cape Peninsula University of Technology, 2017.Real-time remote monitoring of Africa’s resources, such as water quality, by using terrestrial sensors is impeded by the limited connectivity over the vast rural areas of the continent. Without such monitoring, the effective management of natural resources, and the response to associated disasters such as flooding, is almost impossible. A constellation of nanosatellites could provide near real-time connectivity with ground-based sensors that are distributed across the continent. This study evaluates the high level development of a mission design for a near real-time remote monitoring CubeSat constellation and ground segment for in-situ monitoring in regions of interest on the African continent. This would facilitate management of scarce resources using a low-cost constellation. To achieve this, the design concept and operation of a Walker constellation are examined as a means of providing connectivity to a low bit rate sensor network distributed across geographic areas of interest in South Africa, Algeria, Kenya and Nigeria. The mission requirements include the optimisation of the constellation to maintain short revisit times over South Africa and an investigation of the required communications link to perform the operations effectively. STK software is used in the design and evaluation of the constellations and the communications system. The temporal performance parameters investigated are access and revisit times of the constellations to the geographic areas mentioned. The types of constellation configurations examined, involved starting with a system level analysis of one satellite. This seed satellite has known orbital parameters. Then a gradual expansion of two to twelve satellites in one, two and three orbital planes follows. VHF, UHF and S-band communication links are considered for low data rate in-situ monitoring applications. RF link budgets and data budgets for typical applications are determined. For South Africa, in particular, a total of 12 satellites evenly distributed in a two-plane constellation at an inclination of 39° provide the optimal solution and offer an average daily revisit time of about 5 minutes. This constellation provides average daily access time of more than 16 hours per day. A case study is undertaken that decribes a constellation for the provision of maritime vessel tracking in the Southern African oceans using the Automated Information System (AIS). This service supports the Maritime Domain Awareness (MDA) initiative implemented by the South African Government, under its Operation Phakisa.
National Research Foundation (NRF) French South African Institute of Technology (F’SATI)
3
Abouarboub, Ahmed Ali Mohamed. "In-situ validation of three-phase flowmeters using capacitance sensing techniques." Thesis, University of Derby, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396508.
Full text
4
Badmaarag, Ulzii-Orshikh. "Optical Chemical Sensing Device for In-situ Non-Invasive Gas Monitoring." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1583155117533193.
Full text
5
Chen, Zhiqiang. "Monitoring water quality in Tampa Bay : coupling in situ and remote sensing." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001777.
Full text
6
Xiong, Rentian. "In situ sensing for chemical vapor deposition based on state estimation theory." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/22711.
Full textAbstract:
Thesis (Ph. D.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2008.Committee Chair: Gallivan, Martha; Committee Member: Ferguson, Ian; Committee Member: Henderson, Cliff; Committee Member: Hess, Dennis; Committee Member: Lee, Jay.
7
Evers-King, Hayley Louise. "Phytoplankton community structure determined through remote sensing and in situ optical measurements." Doctoral thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13076.
Full textAbstract:
Includes bibliographical references.Linking variability in optical signals with phytoplankton community characteristics is important to extend the use of the vast resource that is the satellite ocean colour archive. Detection of species, functional types or size classes has been addressed through a spectrum of empirical to analytical approaches. A key step in developing these techniques is quantifying the sensitivity in reflectance, which can be attributed to phytoplankton characteristics (e.g cell size) under different optical regimes. Ultimately, highly spatially and temporally resolved information on phytoplankton characteristics can help the global scientific community to answer important questions relating to primary ecosystem variability. In the southern Benguela, Harmful Algal Blooms threaten public health and the economic viability of fishery and aquaculture industries in the region. Concurrently, the dominance of phytoplankton biomass amongst optically significant constituents in the southern Benguela makes the region ideal for assessing the extent to which phytoplankton characteristics beyond biomass can influence the ocean colour signal. A forward and inverse approach is presented. Phytoplankton absorption and back scattering are generated from a phytoplankton particle population model coupled to two radiative transfer approaches: a reflectance approximation and the radiative transfer model, EcoLight-S. Non-linear optimisation inversion schemes are then implemented. A simulated dataset is created to investigate how much variability in reflectance can be associated with changes in phytoplankton cell size in different bio-optical water types. This dataset is inverted to investigate the errors inherent in the inversion process as a result of ambiguity. Comparison of the two radiative transfer techniques allows for consideration of the suitability of approximations for bidirection-ality and subsurface propagation. The inversion algorithm is then applied to hyperspectral in situ radiometric data to provide validation and further assessment of errors from all sources. Results indicate that size related sensitivity in reflectance is highly dependent on phytoplank-ton biomass, as determined by the relative phytoplankton contribution to the Inherent Optical Property budget. The algorithm is finally applied to ten years of MERIS data covering the southern Benguela. A time series of biomass and cell size is presented and metrics developed to demonstrate the utility of this approach for identifying previously unobserved interannual variability in Harmful Algal Blooms.
8
Dixon, Benjamin Deon. "In-situ monitoring using nano-satellites : a systems level approach." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2194.
Full textAbstract:
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2015.Traditional satellite systems employed for use with in-situ monitoring systems are large satellites that have a long development time, high cost and complex sub-systems. The end use of relaying data for in-situ monitoring becomes a costly application for the end user. Shifting this application to make use of nano-satellites, such as CubeSats, for data relaying will make the application more attractive to the end user when measurements are required outside existing ground based communications infrastructure. CubeSats are small, simple satellites that yield a short development time and very low cost compared to conventional satellites. Their sub-systems are generally built from off the shelf components. This keeps the designs simple, manufacture cost low with the potential for flying the latest technologies. This research set out to analyse various scenarios related to in-situ monitoring governed by parameters such as the maximum revisit time, satellite orbit altitude, quantity of sensor nodes and data quantity relayed in the system. A systems level approach is used to analyse each designed scenario using a simulation tool called Systems Tool Kit by Agilent Graphics Incorporated. The data acquired for each scenario through simulation was validated using theoretical approximation methods, which included parameters such as coverage potential, total node access time, communication link performance, power resources, memory resources, access time and number of ground stations. The focus was put on these parameters since they are the main constraints when designing a system using nano-satellites. The outcome of the research was to create an analysis reference for designing an in-situ monitoring system using nano-satellites. It outlines the methods used to calculate and simulate each of the constraints governing the system. Each designed scenario showed satisfactory performance within the defined parameters and can be practically implemented as a reference for designing similar systems.
National Research Foundation
South African National Space Agency
9
Kautz, Jess S., and Jess S. Kautz. "In-Situ Cameras for Radiometric Correction of Remotely Sensed Data." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/624563.
Full textAbstract:
The atmosphere distorts the spectrum of remotely sensed data, negatively affecting all forms of investigating Earth's surface. To gather reliable data, it is vital that atmospheric corrections are accurate. The current state of the field of atmospheric correction does not account well for the benefits and costs of different correction algorithms. Ground spectral data are required to evaluate these algorithms better. This dissertation explores using cameras as radiometers as a means of gathering ground spectral data.
I introduce techniques to implement a camera systems for atmospheric correction using off the shelf parts. To aid the design of future camera systems for radiometric correction, methods for estimating the system error prior to construction, calibration and testing of the resulting camera system are explored. Simulations are used to investigate the relationship between the reflectance accuracy of the camera system and the quality of atmospheric correction. In the design phase, read noise and filter choice are found to be the strongest sources of system error. I explain the calibration methods for the camera system, showing the problems of pixel to angle calibration, and adapting the web camera for scientific work. The camera system is tested in the field to estimate its ability to recover directional reflectance from BRF data. I estimate the error in the system due to the experimental set up, then explore how the system error changes with different cameras, environmental set-ups and inversions. With these experiments, I learn about the importance of the dynamic range of the camera, and the input ranges used for the PROSAIL inversion. Evidence that the camera can perform within the specification set for ELM correction in this dissertation is evaluated. The analysis is concluded by simulating an ELM correction of a scene using various numbers of calibration targets, and levels of system error, to find the number of cameras needed for a full-scale implementation.
10
Museler, Erica A. "A comparison of in-situ measurements and satellite remote sensing of underwater visibility." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FMuseler.pdf.
Full textAbstract:
Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, March 2003.Thesis advisor(s): Philip A. Durkee. Includes bibliographical references (p. 57-59). Also available online.
11
Fuchs, Eran 1963. "Underwater in situ optical measurements and coral fluorescence for shallow water remote sensing." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38189.
Full text
12
Comin, Cabrera Francisco J. "In-situ soil sensing for planetary micro-rovers with hybrid wheel-leg systems." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/809953/.
Full textAbstract:
Rover missions exploring other planets are tightly constrained regarding the trade-off between safety and traversal speed. Detecting and avoiding hazards during navigation is capital to preserve the mobility of a rover. Low traversal speeds are often enforced to assure that wheeled rovers do not become stuck in challenging terrain, hindering the performance and scientific return of the mission. Even such precautions do not guarantee safe navigation due to non-geometric hazards hidden in the terrain, such as sand traps beneath thin duricrusts. These issues motivate the research of the interaction with rough and sandy planetary terrains of conventional and innovative robot locomotion concepts. Hybrid wheel-legs combine the mechanical and control simplicity of wheeled locomotion with the enhanced mobility of legged locomotion. This concept has been rarely proposed for planetary exploration and the study of its interaction with granular terrains is at a very early stage. This research focuses on advancing the state-of-the-art of wheel-leg-soil interaction analysis and applying it through in-situ sensing to simultaneously improve the speed and safety of planetary rover missions. The semi-empirical approach used combines both theoretical modelling and experimental analysis of data obtained in laboratory and field analogues. A novel light-weight, low-power sensor system, capable of reliably detecting wheel-leg sinkage and slippage phenomena on-the-fly, is designed, implemented and tested both as part of a simplified single-wheel-leg test bed and integrated in a fully mobile micro-rover. Moreover, existing analytical models for the interaction between deformable terrain and heavily-loaded wheels or lightly-loaded legs are adapted to the generalised medium-loaded multi-legged wheel-leg case and combined into hybrid approaches for better accuracy, as validated against experimental data. Finally, the soil sensor system and analytical models proposed are used to develop and prove the effectiveness of different solutions for soil characterisation, trafficability assessment and terrain classification based on non-geometric physical properties.
13
Harlow, Robert C. "Remote and in situ measurements of soil and vegetation water content." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280356.
Full textAbstract:
Accurate estimates of soil moisture are necessary to predict evapotranspiration, runoff, infiltration, and groundwater recharge and, through these variables, weather, climate, and fire and flood frequencies. This dissertation is motivated by the need to estimate soil water content from remotely sensed passive microwave emission. Two different approaches are taken: (1) improved modeling of the microwave emission from the land surface; and (2) measurements of the average dielectric properties of the soil media and vegetation canopies. Consequently, the first part of the dissertation describes how a stratified dielectric model of the microwave emission from the soil was extended to take into account the effects of vegetation. The model parameters were calibrated using observed data and a robust optimization routine. However, the availability of measurements of some of these parameters, particularly the profile of dielectric permittivity of the canopy, would facilitate a more complete evaluation of the accuracy of the extended microwave emission model. The second part of this dissertation describes progress towards the development of a technique to measure the dielectric of vegetation canopies. This technique is based on gated time domain transmission measurements through the substance of interest. Preliminary studies carried out using soils with varying salinity and water content and vegetation show (1) an unexpected response of the signal to saline soils, and (2) a possible dielectric signature of the onset of stress in plant stems.
14
Detrich, Kahlil. "Electroding Methods for in situ Reverse Osmosis Sensors." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/31207.
Full textAbstract:
The purpose of this work is to develop and evaluate electroding methods for a reverse osmosis (RO) membrane that results in an in situ sensor able to detect RO membrane protein fouling. Four electroding techniques were explored: i) gold exchange-reduction, ii) encapsulated carbon grease, iii) â direct assembly processâ (DAP), and iv) platinized polymer graft. The novel platinized polymer graft method involves chemically modifying the RO membrane surface to facilitate platinization based on the hypothesis that deposition of foulant on the platinized surface will affect platinum/foulant/solution interfacial regions, thus sensor impedance. Platinized polymer graft sensors were shown to be sensitive to protein fouling.
Electrodes were characterized by their electrical properties, SEM and XPS. Assembled sensors were evaluated for sensitivity to electrolyte concentration and protein fouling. Micrographs showed coating layers and pre-soak solution influence gold exchange-reduction electrode formation. High surface resistance makes gold exchange-reduction an unsuitable method. Concentration sensitivity experiments showed carbon grease and DAP electroding methods produce unusable sensors. Carbon grease sensors have time-dependent impedance response due to electrolyte diffusion within the micro-porous polysulfone support. DAP electroded sensors proved quite fragile upon hydration; their impedance response is transient and lacks predictable trends with changes in concentration. A parametric study of the platinized polymer graft method shows amount of grafted monomer correlates to grafting time, and deposited platinum is a function of exchange-reduction repetitions and amount of grafted monomer. Platinized polymer graft sensors were fouled in both dead-end and cross-flow RO systems, and their impedance trends, while varying between sensors, indicate protein-fouling sensitivity.Master of Science
15
Neill, Simon Philip. "Remote sensing, in-situ and modelling studies of tidal fronts in the Tay Estuary." Thesis, University of Strathclyde, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249046.
Full text
16
Drocourt, Yoann. "Using remote sensing, in-situ measurements and data visualisation to investigate tidewater glaciers behaviour in Greenland." Thesis, Swansea University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678404.
Full textAbstract:
The aims of this thesis was to participate in the improvement of the current knowledge of tidewater glaciers' behaviour in Greenland. This was achieved by a multi-scale and multi-disciplinary approach.
17
Ranisavljević, Elisabeth. "Cloud computing appliqué au traitement multimodal d’images in situ pour l’analyse des dynamiques environnementales." Thesis, Toulouse 2, 2016. http://www.theses.fr/2016TOU20128/document.
Full textAbstract:
L’analyse des paysages, de ses dynamiques et ses processus environnementaux, nécessite d’acquérir régulièrement des données des sites, notamment pour le bilan glaciaire au Spitsberg et en haute montagne. A cause des mauvaises conditions climatiques communes aux latitudes polaires et à cause de leur coût, les images satellites journalières ne sont pas toujours accessibles. De ce fait, les événements rapides comme la fonte de la neige ou l'enneigement ne peuvent pas être étudiés à partir des données de télédétection à cause de leur fréquence trop faible. Nous avons complété les images satellites par un ensemble de de stations photo automatiques et autonomes qui prennent 3 photos par jour. L’acquisition de ces photos génère une grande base de données d’images. Plusieurs traitements doivent être appliqués sur les photos afin d’extraire l’information souhaitée (modifications géométriques, gestion des perturbations atmosphériques, classification, etc). Seule l’informatique est à même de stocker et gérer toutes ces informations. Le cloud computing offre en tant que services des ressources informatiques (puissance de calcul, espace de stockage, applications, etc). Uniquement le stockage de la masse de données géographique pourrait être une raison d’utilisation du cloud computing. Mais en plus de son espace de stockage, le cloud offre une simplicité d’accès, une architecture scalable ainsi qu’une modularité dans les services disponibles. Dans le cadre de l’analyse des photos in situ, le cloud computing donne la possibilité de mettre en place un outil automatique afin de traiter l’ensemble des données malgré la variété des perturbations ainsi que le volume de données. A travers une décomposition du traitement d’images en plusieurs tâches, implémentées en tant que web services, la composition de ces services nous permet d’adapter le traitement aux conditions de chacune des donnéesAnalyzing landscape, its dynamics and environmental evolutions require regular data from the sites, specifically for glacier mass balanced in Spitsbergen and high mountain area. Due to poor weather conditions including common heavy cloud cover at polar latitudes, and because of its cost, daily satellite imaging is not always accessible. Besides, fast events like flood or blanket of snow is ignored by satellite based studies, since the slowest sampling rate is unable to observe it. We complement satellite imagery with a set of ground based autonomous automated digital cameras which take 3 pictures a day. These pictures form a huge database. Each picture needs many processing to extract the information (geometric modifications, atmospheric disturbances, classification, etc). Only computer science is able to store and manage all this information. Cloud computing, being more accessible in the last few years, offers as services IT resources (computing power, storage, applications, etc.). The storage of the huge geographical data could, in itself, be a reason to use cloud computing. But in addition to its storage space, cloud offers an easy way to access , a scalable architecture and a modularity in the services available. As part of the analysis of in situ images, cloud computing offers the possibility to set up an automated tool to process all the data despite the variety of disturbances and the data volume. Through decomposition of image processing in several tasks, implemented as web services, the composition of these services allows us to adapt the treatment to the conditions of each of the data
18
Rogozinski, Jeffrey David. "In-situ frequency-dependent electromagnetic sensing for monitoring physical and chemical attributes during chemical processing." W&M ScholarWorks, 2000. https://scholarworks.wm.edu/etd/1539623978.
Full textAbstract:
The objective of this research was to develop an in-situ sensing technique that monitors the molecular-level response of ions and dipoles to an applied electric field in order to characterize the changes in state of a polymer resin during chemical processing. This technique needs to be capable of monitoring the reaction progress not only in the laboratory setting but also in-situ in the processing tool or reaction environment. Frequency Dependent Electromagnetic Sensing (FDEMS) was selected for this task.;This dissertation investigates the applicability of FDEMS to monitoring two types of processing methods: reactive and batch reactor. The reactive processing system examined involves the processing of a high glass transition thermoplastic, either polyethylene ether or polyether imide blended with a thermoset, diglycidyl ether of bisphenol-A and 4,4'-methylene bis (3-chloro 2,6-diethylaniline]. The batch reactor processing systems examined involve the in-situ process control of an industrial batch reactor process involving five different systems: epoxy acrylic, polyester, latex, emulsion for lotions and surfactants.
19
Boulart, Cedric. "Methane in deep sea hydrothermal plumes : development of a new in-situ methane sensing technology." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/65667/.
Full textAbstract:
Information on the concentration and distribution of dissolved methane (CH4), together with other geochemical tracers, in real time is of great value in detecting, monitoring, and understanding the functioning of hydrothermal plumes. Water column anomalies of light transmission, dissolved CH4, manganese (Mn), and iron (Fe) were located over segments 15 and 16 of the Central Indian Ridge (CIR 20ºS), in December 2006. Along segment 15, a hydrothermal plume was present at 19°33’S/65°50’E. The source might be located north of that position and dispersed along the western flank by NW-SE currents. Methane to manganese ratios suggest that methane is produced by magmatic processes. On Segment 16, evidence for 1 or 2 hydrothermal plumes were detected over a lava plain (18°20’S/65°18’E). These data suffered from uncertainties due to sampling issues, which demonstrate the need for a reliable in-situ methane sensing technology. Current in-situ methane sensing technology is based on gas partitioning across gas permeable membranes, which are poorly characterised and variable in terms of permeability and environmental pressures. Two optical techniques were laboratory tested for the measurement of dissolved methane; Near Infrared Fibre-optic Evanescent Wave Spectroscopy (FEWS) and Surface Plasmon Resonance (SPR). No detection (at the µM level) was possible with FEWS, but the second technique using SPR sensors associated with a methane specific binding chemically showed great promise. A limit of detection of 0.2 nM and a linear concentration range from 1 to 300 nM was demonstrated, under a range of temperature and salinity. In-situ deployments confirmed the suitability of the method for in-situ measurements. Values given by the sensor correlated well with the concentrations measured by traditional techniques. Future work is needed to decrease instrumental noise and to reduce the response time, and associated hysteresis effect.
20
Mountford, Gillian L. "Characterising UK vegetation phenology : an examination of in situ, near-surface and remote sensing techniques." Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/422158/.
Full text
21
Zhang, Tianran. "Smoke emissions from eastern China's agricultural residue burning assessed using remotely sensing and in situ measurement." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/smoke-emissions-from-eastern-chinas-agricultural-residue-burning-assessed-using-remotely-sensing-and-in-situ-measurement(a804d660-e6fd-4f0c-8441-799746ecbdac).html.
Full textAbstract:
This thesis exploits satellite remote sensing and in situ smoke measurement to estimate emissions from agricultural residue burning in Eastern China, a densely populated region with often poor air quality and which is one of China’s main agricultural burning regions. A new active fire (AF) detection and fire radiative power (FRP) retrieval algorithm is developed for use with the Suomi-NPP satellite’s VIIRS sensor, whose high spatial resolution band “I’ Bands provide an ability to detect the smaller (low FRP) fires missing from current satellite AF datasets. Daily fire radiative energy (FRE) – and thus fuel consumption - estimates are obtained by a link to diurnal cycle information from the Himawari geostationary spacecraft, and used to estimate emissions (CO2, CO, PM2.5 and BC) via multiplication by emissions factors derived from in situ measurements of smoke made by exploiting a new multi-sensor sampling design. Results show that VIIRS detects AFs with an FRP-minimum below 0.5 MW (cf. 6–8 MW for MODIS), and identifies typically 5 to 10 times more AF pixels across Eastern China. The resulting high spatiotemporal resolution agricultural fire emissions inventory is compared to two state-of-the-art global fire databases (GFAS and GFED), and shows fuel consumption emissions estimates 1 to 4 times higher for the burning seasons, highlighting the significance of the formally undetected low FRP active fires. Mean annual emissions of CO2, CO, PM2.5 and BC range from 16932 to 31107, 562 to 1035, 70 to 130, 6 to 11 Gg respectively (mean of 2012 – 2015), and the interannual variations seen appear potentially linked to changing farming activity and local fire management practices. This research has improved understanding and quantification of agricultural residue burning in Eastern China, and the new “small fire” detection capability could in future be extended to wider (even global) scales, particularly in agricultural burning regions, in order to reduce the low biases that have been now clearly exposed in current fire emissions estimates of those areas.
22
Schirru, Michele. "Development of an ultrasonic sensing technique to measure lubricant viscosity in engine journal bearing in-situ." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/12980/.
Full textAbstract:
This work presents a novel technique to measure viscosity in-situ and in real time in engine component interfaces by means of an ultrasonic technique. Viscosity is a key parameter in the characterization of lubrication regime in engine parts because it can be related to friction in the contact, and to the lubricant film thickness. Ultrasound is a non-destructive and non-invasive technique that is based on the reflection of sound from interfaces. The reflection from a solid-air boundary can identify, for instance, the presence of a crack in a material, while reflection from a solid-liquid interface can help detecting the properties of the liquid sample. Reflection of longitudinal waves measures fluid film thickness and chemical composition, while the reflection of ultrasonic shear waves measures the fluid viscosity. The viscosity measurements based on ultrasonic reflection from solid-fluid boundaries are referred to as reflectance viscometry techniques. Common ultrasonic reflectance viscometry methods can only measure the viscosity of Newtonian fluids. This work introduces a novel model to correlate the ultrasonic shear reflection coefficient with the viscosity of non-Newtonian oils by means of the Maxwell model analogy. This algorithm overcomes the limitation of previous models because it is suitable for the analysis of common engine oils, and because it relies only on measurable parameters. However, viscosity measurements are prohibitive at the metal-oil interfaces in auto engines because when the materials in contact have very different acoustic impedances the sound energy is almost totally reflected, and there is very little interaction between the ultrasonic wave and the lubricant. This phenomenon is called acoustic mismatch. When acoustic mismatch occurs, any valuable information about the liquid properties is buried in measurement noise. To prove this, the common reflectance set-up was tested to measure the viscosity of different lubricants (varying from light base oils to greases) using aluminium as solid boundary. More than 99.5% of the ultrasonic energy was reflected for the different oils, and accurate viscosity measurement was not possible because the sensitivity of the ultrasonic measurement at the current state of the art is of ±0.5%. Consequently, the discrimination by viscosity of the oil tested was not possible. In this study a new approach is developed. The sensitivity of the ultrasonic reflectance method is enhanced with a quarter wavelength matching layer material. This material is interleaved between metal and lubricant to increment the ultrasonic measurement sensitivity. This layer is chosen to have thickness and mechanical properties that induce the ultrasonic wave to resonate at the solid-liquid interface, at specific frequencies. In this work, resonance is associated with the destructive interaction between the wave that is incident to the matching layer and the wave that is reflected at the matching layer-oil interface. This solution brings a massive increment in the ultrasonic measurement sensitivity. The matching layer technique was first tested by enhancing the sensitivity of the aluminium-oil set-up that was affected by acoustical mismatch. A thin polyimide layer was used as a matching layer between aluminium and the engine oil. This probe was used as ultrasonic viscometer to validate the sensing technique by comparison with a conventional viscometer and by applying a temperature and pressure variation to the samples analysed. The results showed that the ultrasonic viscometer is as precise as a conventional viscometer when Newtonian oils are tested, while for Non-Newtonian oils the measurement is frequency dependent. In particular, it was noticed that at high ultrasonic frequency only the viscosity of the base of the oil was measured. The ultrasonic viscometer was used to validate the mathematical model based on the Maxwell analogy for the correlation of the ultrasonic response with the liquid viscosity. At a second stage, this technique was implemented in a journal bearing. The ultrasonic viscometer was mounted in the shaft to obtain the first viscosity measurement along the circumference of a journal bearing at different rotational speeds and loads. The ultrasonic viscometer identified the different viscosity regions that are present in the journal bearing: the inlet, the regions characterized by the rise in temperature at the contact and the maximum loaded region were the minimum film thickness occurs. The results were compared with the analytical isoviscous solution of the Reynolds equation to confirm that the shape of the angular position-viscosity curves was correct. Finally, the method was preliminarily tested on a coated shell bearing to show that the coating presents in bearing, like iron-oxide or babbit, is a good matching layer for the newly developed ultrasonic viscometer technique. This means that ultrasonic transducers, with sizes as small as a pencil tip, have the potential to be mounted as viscometers in real steel bearings where the coating layer in contact with the fluid acts as a matching layer. Overall, the results obtained showed that this technique provides robust and precise viscosity measurements for in-situ applications in engine bearings.
23
Mihalikova, Maria. "Mesoscale processes in the polar atmosphere : radar remote sensing, balloon-borne in situ measurements and modelling." Doctoral thesis, Luleå tekniska universitet, Rymdteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18191.
Full textAbstract:
Mesoscale processes (atmospheric phenomena with horizontal scales ranging from a few tens to several hundred kilometres and lasting from a few tens of minutes to a few days) have the potential to influence the chemical composition of the troposphere. Tropopause folds and mountain waves are two important types of mesoscale processes. Concentrations and gradients of trace gases like ozone (O3) can be influenced by these processes. Tropopause folds bring ozone-rich stratospheric air to lower altitudes. Mountain waves and turbulence associated with them influence O3 gradients in the troposphere. Tropospheric O3 is a toxic pollutant and a short-lived greenhouse gas with an influence on the lifetime of many other trace gases. Understanding of its long-term development and budgets are important. For this, better understanding, generalization and representation of mesoscale processes are necessary. Observations made by the 52MHz wind-profiler radar ESRAD (ESrange RADar) and the 54.5MHz wind-profiler radar MARA (Movable Atmospheric Radar for Antarctica) served as the basis for this study. ESRAD is located close to Kiruna in arctic Sweden and has been in operation since July 1996. This is a site with frequent mountain wave activity. By analysis of ESRAD and sonde data we have studied vertical mixing and turbulence associated with mountain waves. An attempt was made to show the influence of these processes on relaxation of the O3 gradient in the lower troposphere. Additional balloon-borne in situ measurements of vertical profiles of atmospheric characteristics (temperature, humidity, O3 mixing ratio) complement the radar measurements and aid in correct identification and improved understanding of the observed processes as well as of the radar backscatter signal itself. MARA was operated at the Swedish summer station Wasa (73°S, 13.5°W) during austral summer 2010/2011 and at the Norwegian year-round station Troll (72°S, 2.5°E) nonstop since December 2011. During its operation at the Wasa station, ozonesonde measurements were successfully undertaken during the passage of a tropopause fold. These provided validity to the radar measurements and proved them to be a useful tool for tropopause fold studies, for the first time at Antarctic latitudes. Data gathered at the Troll station exhibit signs of an annual cycle of tropopause folds with winter maximum and summer minimum in their occurrence rate which is similar to the observed behaviour in the northern hemisphere. Comparisons with ECMWF (European Centre for Medium-Range Weather Forecasts) model data and the WRF model (Advanced Research and Weather Forecasting) show that higher resolution models such as WRF are needed for more adequate representation of these processes. High resolution models can in return serve as a basis for studies of areas that are not at all or only partially covered by measurement networks, as well as for global studies. Thus they can provide useful information about atmospheric transport and the state of trace gases like O3.Godkänd; 2013; 20130101 (marmih); Disputation Ämne: Rymdteknik/Space Engineering Opponent: Senior lecturer Suzanne Gray, Dept of Meteorology, University of Reading, Reading, United Kingdom Ordförande: Professor Sheila Kirkwood, Institutionen för system- och rymdteknik, Luleå tekniska universitet, Luleå /Svenska institutet för rymdfysik, Kiruna Tid: Måndag den 11 februari 2013, kl 09.00 Plats: Aula, Institutet för rymdfysik, Kiruna
24
Chane, Andrea. "Régulation, expression in situ et biostimulation de l'activité quorum-quenching d'un agent de biocontrôle : Rhodococcus erythropolis." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMR031.
Full textAbstract:
Le biocontrôle est défini comme un ensemble de méthodes de protection des végétaux par l’utilisation de mécanismes naturels. Son principe repose sur la gestion des équilibres des populations d’agresseurs plutôt que sur leur éradication. La protection des cultures de la pomme de terre Solanum tuberosum contre les bactéries pectinolytiques (Dickeya et Pectobacterium) a été précédemment proposée comme une application du biocontrôle. Il s’agit ici de perturber (quencher) la communication quorum-sensing (QS) utilisée par l’agent pathogène pour coordonner son attaque et sa virulence. Afin d’optimiser cette méthode de lutte par quorum-quenching (QQ) et d’en contrôler l’efficacité, nous avons étudié la voiecatabolique des -lactones d’un agent de biocontrôle, la bactérie Rhodococcus erythropolis. Cette voie est impliquée dans la dégradation des signaux N-acyl-homoserine lactones du pathogène. Nous avons d’abord étudié le rôle du répresseur QsdR ainsi que la régulation transcriptionnelle de l’opéron qsd impliqué dans la dégradation des signaux. La compréhension de cette régulation a permis de générer des biosenseurs capables de monitorer les activités QS du pathogène et QQ du protecteur. Sous microscopie confocale à balayage laser, ces outils ont apporté des preuves visuelles du rôle et du lien entre ces deux activités dans les tissus du tubercule. Enfin, la faible spécificité du répresseur QsdR pour ses ligands, apermis de proposer la -caprolactone, un analogue structural des signaux de QS, comme inducteur de l’opéron qsd. Dans l’ensemble, ces travaux permettent d’approfondir nos connaissances sur le rôle et le fonctionnement du QQ chez R. erythropolis. Ils permettent aussi d’envisager le contrôle de la maladie via un agent dont l’activité de QQ pourra être biostimulée par des lactones peu coûteuses lors de la formulation puis de l’épandage aux champsBiocontrol is defined as a set of plant protection methods through the use of natural mechanisms. Its principle involves the control of populations of aggressors rather than their eradication. The protection of the potato Solanum tuberosum against soft-rot bacteria (Dickeya and Pectobacterium) has been previously proposed as an application of biocontrol. This involves disturbing the quorum-sensing (QS) communication used by the pathogen to coordinate its attack and virulence. In order to optimize this quorum-quenching (QQ) biocontrol method and to control its effectiveness, we have studied the catabolic pathway of -lactones of a biocontrol agent, the Rhodococcus erythropolis bacterium. This pathway is involved in the degradation of the pathogen N-acyl-homoserine lactones signals. We firststudied the role of the QsdR repressor as well as the transcriptional regulation of the qsd operon involved in signal degradation. The understanding of this regulation has made it possible to generate biosensors capable of monitoring the QS of the pathogen and QQ of the protector. Under confocal laser scanning microscopy, these tools provided visual evidence of the role and link between these two activities in the tuber tissues. Finally, the low specificity of the QsdR repressor for its ligands made it possible to propose the -caprolactone, a structural analog of QS signals, as an inducer of the qsd operon. Overall, this work provides insight into the role and function of QQ in R. erythropolis. It also allows to envisage the control of the disease using a biocontrol agent whose QQ activity can be biostimulated by inexpensive lactones during formulation then spreading in the field
25
Vuki, Veikila Curu. "Long term changes of Suva reef flat communities from conventional in situ survey and remote sensing methods." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241145.
Full text
26
Gu, Jie. "Characterization of in-situ Ca²⁺ -sensing mechanisms and stanniocalcin-1 target cells in gills of Japanese eels." HKBU Institutional Repository, 2014. https://repository.hkbu.edu.hk/etd_oa/74.
Full textAbstract:
Calcium ion has diverse beneficial roles in living organisms. Failure in Ca2+ homeostasis affects a variety of molecular and cellular processes, ultimately leading to many pathological consequences. In mammals, body Ca2+ homeostasis is maintained by the coordinated calcium (re)absorption that occurs in the small intestines, kidneys and bones, and is under tight hormonal control. In fish, two special organs, Corpuscles of Stannius (CS) glands and gills form a regulatory circuit to detect and regulate blood Ca2+ homeostasis. However, the underlying molecular mechanism in the regulation of gill Ca2+ uptake has not been fully examined. Moreover, some putative biological active substances in CS glands have not been identified. To address these research questions, a euryhaline fish, Japanese eel (Anguilla japonica) was used as an animal model for the study. Fish gill is equipped with epithelial calcium channel (ECaCl) as gatekeeper of Ca2+ entry, and membrane Ca2+-ATPase (PMCA) for Ca2+ efflux. To test if branchial ECaCl and PMCA responded to change in water Ca2+ level, we investigated the changes in fish adapted in artificial freshwater (AFW), Ca2+-deficient AFW (D-AFW) or high Ca2+-AFW (H-AFW). Our data illustrated both short-term and long-term effects on modulations of the transporters. The changes correlated with expression levels of stanniocalcin-1 (STC-1) in CS glands. This part of study supports the regulatory circuit between gills and the glands. In primary cell culture of Japanese eel gill cells, Ca2+ sensing was shown to be mediated by Ca2+ sensing receptor (CaSR) coupled to phospholipase C (PLC)-extracellular signal-regulated kinase (ERK) and PLC-inositol triphosphate (IP3)-Ca2+/calmodulin-dependent protein kinase-II (CaMK-II) pathways. And CaSR-STC-1/cyclo-oxygenase-2 (COX-2) mediated protective pathway in gill cells that exerts a possible protective mechanism against an increase in intracellular Ca2+ levels associated with transepithelial Ca2+ transport. Apparently, the protective effects against Ca2+-mediated cytotoxicity of gill cell were mediated by STC-1 binding on gill cells that led to elevations of cytosolic cAMP. In a follow-up experiment of using Ca2+-imaging system in a model of thapsigargin (TG)-induced elevation of cytosolic Ca2+, a hypocalcemic action of STC-1 was demonstrated and was found to be mediated by cAMP and COX-2 pathway. To further determine the gene expressed in CS gland responsive to changes in water salinity, the first transcriptome database of CS glands from fish adapted in freshwater or seawater condition. A de novo assembly of RNA sequencing data generated 11747 unigenes and revealed 475 genes that were differentially expressed. Three functional clusters: (1) Ca2+-metabolism, (2) blood pressure and (3) ion-osmoregulation were revealed. Gene targets, in addition to STC-1 in related to the regulation of calcium metabolism and blood pressure, like calcitonin, atrial natriuretic peptide-converting enzyme and endothelin-converting enzyme 1 were identified. Taken together this thesis described a comprehensive study on the functional circuit between gills and CS glands to decipher the regulation and functions of transporters and hormones in calcium metabolism in fish.
27
Zhang, Ning. "Soil Moisture Mapping in South Central United States by Blending In-situ, Modeled and Remote Sensing Data." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1584465849013608.
Full text
28
Dall'Amico, Johanna Therese. "Multiscale analysis of soil moisture using satellite and aircraft microwave remote sensing, in situ measurements and numerical modelling." Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-146263.
Full text
29
WAN, JINGFANG. "In Situ Optically Trapped Probing System for Molecular Recognition and Localization." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250626752.
Full text
30
Cho, Soon. "Real-Time In-Situ Chemical Sensing in AlGaN/GaN Metal-Organic Chemical Vapor Deposition Processes for Advanced Process Control." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1798.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2004.Thesis research directed by: Material Science and Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
31
Raitsos-Exarchopoulos, Dionysios. "Understanding of the variability of phytoplankton ecosystem function properties : a synergistic use of remote sensing and in situ data." Thesis, University of Plymouth, 2006. http://hdl.handle.net/10026.1/2321.
Full textAbstract:
The majority of the earth's surface (-71%) is covered by the aquatic environment where 97% of that is the oceanic regime. Almost every part of the aquatic regime is dominated by microscopic plants called phytoplankton. Being at the bottom of the food chain, these ecological drivers influence the earth's climate system as well as the biodiversity trends of other organisms such as zooplankton, fish, sea birds and marine mammals. The aim of this research was to understand the ecology of phytoplankton and assess which environmental, physical, biological, and spatiotemporal factors influence their distribution and abundance. Using this information a knowledge-based expert system discriminated phytoplankton functional types. The ecological knowledge was derived from the Continuous Plankton Recorder (CPR) survey, whereas information regarding the physical regime was acquired from satellite remote sensing. The data matrix was analysed using Generalised Additive Models (GAMs) and Artificial Neural Networks (ANNs). The significant relationships developed by the synergistic use of CPR measure of phytoplankton biomass and satellite chlorophyll a (Chl-a), allowed the production of a >50 years Chl-a dataset in the Northeast Atlantic and North Sea. It was found that the documented mid-80s regime shift corresponded to a 60% increase in Chl-a since 1948; a result of an 80% increase in Chl-a during winter alongside a smaller summer increase. GAMs indicated that the combined effects of high solar radiation, shallow mixed layer depth and increased temperatures explained more than 89% of the coccolithophore variation. The June 1998 bloom, which was associated with high light intensity, unusually high sea-surface temperature (SST) and a very shallow mixed layer, was found to be one of the most extensive ( -1 million km² ) blooms ever recorded. There was a pronounced SST shift in the mid-1990s with a peak in 1998, suggesting that exceptionally large blooms are caused by pronounced environmental conditions and the variability of the physical environment strongly affects the spatial extent of these blooms. Diatom abundance in the epipelagic zone of the Northern North Atlantic was mainly driven by SST. The ANNs indicated that higher SSTs could lead to a rapid decrease in diatom abundance; increased SST can stratify the water column for longer preventing nutrients from being available. Therefore, further increases may be devastating to diatoms but may benefit smaller plankton such as coccolithophores and/or dinoflagellates. Finally, the knowledge gained though the developed methodological approaches was used to identify/discriminate phytoplankton functional groups (diatoms, dinoflagellates, coccolithophores and silicoflagellates) with an accuracy of greater than 70%. The most important information for phytoplankton functional group discrimination was spatiotemporal information, and for the physical environment was SST. Future research aimed at the identification of functional groups from remotely sensed data should include fundamental information on the physical environment as well as spatiotemporal information and not just based on bio-optical measurements. Further development, potential applications and future research are discussed.
32
GeÌrard, Yvan. "Development of a multi-species tunable diode laser spectrometer for the in situ and remote sensing of vehicle emissions." Thesis, University of Huddersfield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430279.
Full text
33
Leyton, Alex Ovando. "Understanding flooding processes of large wetlands of the bolivian amazon through in situ observation, remote sensing and numerical modeling." Instituto Nacional de Pesquisas Espaciais (INPE), 2017. http://urlib.net/sid.inpe.br/mtc-m21b/2017/04.18.17.29.
Full textAbstract:
The Amazonian wetlands of Bolivia, known as the Llanos de Moxos, are believed to play a crucial role in regulating the upper Madeira hydrological cycle, the most important southern tributary of the Amazon River. In addition to its rich natural diversity, the Llanos were the setting for many complex pre-Columbian societies. Because the area is vast and sparsely populated, the hydrological functioning of the wetlands is poorly known. In this thesis we show the feasibility of using multi-temporal flood mapping, based on optical (MODIS M*D09A1) and satellite altimetry (ENVISAT RA-2 and SARAL Altika altimeters) to characterize and monitor flood dynamics and to optimize floodplain simulations within a hydrological model (MHD-INPE model). Initially we analyzed the hydrometeorological configurations that led to the major floods of 2007, 2008 and 2014 in the upper Madeira Basin; Then, with the inclusion of altimetric information, which provided a vertical component for the two-dimensional flood maps, we analyzed the flood dynamics for the whole 2001-2014 period, including both extension and water stage variations that allowed to have initial surface water storage estimations. Finally, we critically analyzed how numerical modeling of the wetlands can be improved using additional remote sensing techniques. Our results showed that large floods are the result of the superimposition of flood waves from major sub-basins of the region and the strong influence of the occurrence of intense rainfall over saturated areas. We had identified relevant features of the flood regime, identifying three groups with particular characteristics in function of its connectivity and dependence to the Andes and piedmonts or to local processes and classified the hydraulic function of the wetlands based on remote sensed imagery. Finally, we demonstrate that remote sensing information is of major importance for improving floodplain simulations using hydrological models. However, there are still clear limitations in the existent remote sensed products for achieving seamless predictions of the hydrological behavior of the Llanos under changing climate.As extensas terras úmidas da Amazonia Boliviana, conhecidas como Llanos de Moxos, desempenham um papel crucial na regulação do ciclo hidrológico do Alto Madeira, o mais importante tributário do sudoeste da Bacia Amazônica. Além de sua riqueza e diversidade natural, os Llanos de Moxos foram o cenário para o desenvolvimento de complexas sociedades pré-colombinas. Devido a área ser extensa e pouco povoada, o funcionamento hidrológico destas terras úmidas é pouco conhecido. Nesta tese mostrou-se a viabilidade do uso de mapeamento multitemporal baseado em imagens ópticas (MODIS M*D09A1) e altimetria por satélite (ENVISAT RA-2 and SARAL AltiKa) para caracterizar e monitorar dinâmicas de inundação e otimizar simulações de planícies de inundação dentro de um modelo hidrológico (o modelo MHD-INPE). Inicialmente analisamos as configurações hidrometeorológicas que levaram aos grandes eventos de inundação dos anos 2007, 2008 e 2014 no Alto Madeira. Em seguida, com a inclusão de informação altimétrica, que forneceu o componente vertical aos mapas de inundação bidimensionais, analisamos as dinâmicas de inundação para o período 2001-2014, incluindo extensão e variações de profundidade das inundações, o que permitiu estimar de armazenamento de água superficial nas planícies. Finalmente analisamos criticamente como a simulação numérica das planícies pode ser otimizada com informação de sensoriamento remoto. Identificamos, baseados em informações de sensoriamento remoto e altimetria, três zonas diferenciadas em função de sua conectividade e dependência aos Andes ou a processos locais. Finalmente, demonstramos que a informação de sensoriamento remoto é de grande importância para a melhoria de simulações de planícies de inundação. No entanto, ainda existem limitações claras nos produtos de sensoriamento remoto para alcançar previsões exatas do comportamento hidrológico dos Llanos de Moxos.
34
Santos, Chandler H. "Linking In-Situ Data with Remote Sensing to Analyze Tropical Glacier Stability and Retreat in the Cordillera Blanca, Peru." TopSCHOLAR®, 2016. http://digitalcommons.wku.edu/theses/1629.
Full textAbstract:
Glaciers are a major source of freshwater around the world, but they are melting at an increased rate due to atmospheric warming resulting from anthropogenic climate change. In addition to temperature increases, light-absorbing particulates on glaciers also are contributing to glacial melt. This research examines how black carbon, released into the air through partial combustion of biofuels, is affecting the surface albedo of glaciers. I also delineate possible sources of black carbon in the Cordillera Blanca region of Peru. Ground data were collected each year from 2011 to 2013 during the local dry season. Effective black carbon (eBC) values were determined using the Light Absorption Heating Method and satellite-derived albedo values were retrieved from NASA’s MODIS MOD10A1 data. Effective black carbon (eBC) values and albedo levels were moderately correlated, showing that albedo decreases with an increase of black carbon, and that this impact can be measured using satellite instruments. Values of eBC did not correlate with spatial proximity to mines, but did correlate with proximity to Huaraz, which likely is the major source of light-absorbing particulates in the region. Further research would benefit from a more extensive source dataset and surface albedo measurements over different seasons.
35
Al-Anbari, Bahir Rami. "Characterization of Parvalbumin and Nxph1 Expression in Lumbar Dorsal Root Ganglia by In Situ Hybridization." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1590091377680566.
Full text
36
Pope, Allen J. "Multispectral classification and reflectance of glaciers : in situ data collection, satellite data algorithm development, and application in Iceland & Svalbard." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/245061.
Full textAbstract:
Glaciers and ice caps (GIC) are central parts of the hydrological cycle, are key to understanding regional and global climate change, and are important contributors to global sea level rise, regional water resources and local biodiversity. Multispectral (visible and near-infrared) remote sensing has been used for studying GIC and their changing characteristics for several decades. Glacier surfaces can be classified into a range of facies, or zones, which can be used as proxies for annual mass balance and also play a significant role in understanding glacier energy balance. However, multispectral sensors were not designed explicitly for snow and ice observation, so it is not self-evident that they should be optimal for remote sensing of glaciers. There are no universal techniques for glacier surface classification which have been optimized with in situ reflectance spectra. Therefore, the roles that the various spectral, spatial, and radiometric properties of each sensor play in the success and output of resulting classifications remain largely unknown. Therefore, this study approaches the problem from an inverse perspective. Starting with in situ reflectance spectra from the full range of surfaces measured on two glaciers at the end of the melt season in order to capture the largest range of facies (Midtre Lovénbreen, Svalbard & Langjökull, Iceland), optimal wavelengths for glacier facies identification are investigated with principal component analysis. Two linear combinations are produced which capture the vast majority of variance in the data; the first highlights broadband albedo while the second emphasizes the difference in reflectance between blue and near-infrared wavelengths for glacier surface classification. The results confirm previous work which limited distinction to snow, slush, and ice facies. Based on these in situ data, a simple, and more importantly completely transferrable, classification scheme for glacier surfaces is presented for a range of satellite multispectral sensors. Again starting with in situ data, application of relative response functions, scaling factors, and calibration coefficients shows that almost all simulated multispectral sensors (at certain gain settings) are qualified to classify glacier accumulation and ablation areas but confuse classification of partly ash-covered glacier surfaces. In order to consider the spatial as well as the spectral properties of multispectral sensors, airborne data are spatially degraded to emulate satellite imagery; while medium-resolution sensors (~20-60 m) successfully reproduce high-resolution (2 m) observations, low-resolution sensors (i.e. 250 m+) are unable to do so. These results give confidence in results from current sensors such as ASTER and Landsat ETM+ as well as ESA’s upcoming Sentinel-2 and NASA’s recently launched LDCM. In addition, images from the Landsat data archive are used to classify glacier facies and calculate the albedo of glaciers on the Brøgger Peninsula, Svalbard. The time series is used to observe seasonal and interannual trends and investigate the role of melt-albedo feedback in thinning of Svalbard glaciers. The dissertation concludes with recommendations for glacier surface classification over a range of current and future multispectral sensors. Application of the classification schemes suggested should help to improve the understanding of recent and continuing change to GIC around the world.
37
Anderson, Eric Ross. "Analysis of rainfall-triggered landslide hazards through the dynamic integration of remotely sensed, modeled and in situ environmental factors in El Salvador." Thesis, The University of Alabama in Huntsville, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1543417.
Full textAbstract:
Landslides pose a persistent threat to El Salvador's population, economy and environment. Government officials share responsibility in managing this hazard by alerting populations when and where landslides may occur as well as developing and enforcing proper land use and zoning practices. This thesis addresses gaps in current knowledge between identifying precisely when and where slope failures may initiate and outlining the extent of the potential debris inundation areas. Improvements on hazard maps are achieved by considering a series of environmental variables to determine causal factors through spatial and temporal analysis techniques in Geographic Information Systems and remote sensing. The output is a more dynamic tool that links high resolution geomorphic and hydrological factors to daily precipitation. Directly incorporable into existing decision support systems, this allows for better disaster management and is transferable to other developing countries.
38
Michel, Anna Pauline Miranda. "Laboratory evaluation of laser-induced breakdown spectroscopy (LIBS) as a new in situ chemical sensing technique for the deep ocean." Cambridge, Mass. : Woods Hole, Mass. : Massachusetts Institute of Technology ; Woods Hole Oceanographic Institution, 2007. http://hdl.handle.net/1912/1957.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007.Title from Web page (viewed on Mar. 24, 2008). "September 2007." Includes bibliographical references.
39
Michel, Anna Pauline Miranda 1976. "Laboratory evaluation of laser-induced breakdown spectroscopy (LIBS) as a new in situ chemical sensing technique for the deep ocean." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42296.
Full textAbstract:
Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2007.Includes bibliographical references.
Present-day expeditionary oceanography is beginning to shift from a focus on short-term ship and submersible deployments to an ocean observatory mode where long-term temporally-focused studies are feasible. As a result, a critical need for in situ chemical sensors is evolving. New sensors take a significant amount of time to develop; thus, the evaluation of techniques in the laboratory for use in the ocean environment is becoming increasingly important. Laser-induced breakdown spectroscopy (LIBS) possesses many of the characteristics required for such in situ chemical sensing, and is a promising technique for field measurements in extreme environments. Although many LIBS researchers have focused their work on liquid jets or surfaces, little attention has been paid to bulk liquid analysis, and especially to the effect of oceanic pressures on LIBS signals. In this work, laboratory experiments validate the LIBS technique in a simulated deep ocean environment to pressures up to 2.76 x 10⁷ Pa. A key focus of this work is the validation that select elements important for understanding hydrothermal vent fluid chemistry (Na, Ca, Mn, Mg, K, and Li) are detectable using LIBS. A data processing scheme that accurately deals with the extreme nature of laser-induced plasma formation was developed that allows for statistically accurate comparisons of spectra. The use of both single and double pulse LIBS for high pressure bulk aqueous solutions is explored and the system parameters needed for the detection of the key analytes are optimized. Using both single and double pulse LIBS, the limits of detection were found to be higher than expected as a result of the spectrometer used in this experimentation. However, the results of this validation show that LIBS possesses the characteristics to be a viable chemical sensing method for in situ analyte detection in high pressure environments like the deep ocean.
by Anna Pauline Miranda Michel.
Ph.D.
40
Verma, Manish K. "Observing and modelling dynamics in terrestrial gross primary productivity and phenology from remote sensing: an assessment using in-situ measurements." Thesis, Boston University, 2013. https://hdl.handle.net/2144/12870.
Full textAbstract:
Thesis (Ph.D.)--Boston University
PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.Terrestrial gross primary productivity (GPP) is the largest and most variable component of the carbon cycle and is strongly influenced by phenology. Realistic characterization of spatio-temporal variation in GPP and phenology is therefore crucial for understanding dynamics in the global carbon cycle. In the last two decades, remote sensing has become a widely-used tool for this purpose. However, no study has comprehensively examined how well remote sensing models capture spatiotemporal patterns in GPP, and validation of remote sensing-based phenology models is limited. Using in-situ data from 144 eddy covariance towers located in all major biomes, I assessed the ability of 10 remote sensing-based methods to capture spatio-temporal variation in GPP at annual and seasonal scales. The models are based on different hypotheses regarding ecophysiological controls on GPP and span a range of structural and computational complexity. The results lead to four main conclusions: (i) at annual time scale, models were more successful capturing spatial variability than temporal variability; (ii) at seasonal scale, models were more successful in capturing average seasonal variability than interannual variability; (iii) simpler models performed as well or better than complex models; and (iv) models that were best at explaining seasonal variability in GPP were different from those that were best able to explain variability in annual scale GPP. Seasonal phenology of vegetation follows bounded growth and decay, and is widely modeled using growth functions. However, the specific form of the growth function affects how phenological dynamics are represented in ecosystem and remote sensingbase models. To examine this, four different growth functions (the logistic, Gompertz, Mirror-Gompertz and Richards function) were assessed using remotely sensed and in-situ data collected at several deciduous forest sites. All of the growth functions provided good statistical representation of in-situ and remote sensing time series. However, the Richards function captured observed asymmetric dynamics that were not captured by the other functions. The timing of key phenophase transitions derived using the Richards function therefore agreed best with observations. This suggests that ecosystem models and remote-sensing algorithms would benefit from using the Richards function to represent phenological dynamics.
41
Williams, Robyn D. "Studies of Mixed-Phase Cloud Microphysics Using An In-Situ Unmanned Aerial Vehicle (UAV) Platform." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7252.
Full textAbstract:
Cirrus clouds cover between 20% - 50% of the globe and are an essential
component in the climate. The improved understanding of ice cloud
microphysical properties is contingent on acquiring and analyzing in-situ and
remote sensing data from cirrus clouds. In ??u observations of microphysical
properties of ice and mixed-phase clouds using the mini-Video Ice Particle Sizer
(mini-VIPS) aboard robotic unmanned aerial vehicles (UAVs) provide a promising
and powerful platform for obtaining valuable data in a cost-effective, safe, and
long-term manner.
The purpose of this study is to better understand cirrus microphysical
properties by analyzing the effectiveness of the mini-VIPS/UAV in-situ platform.
The specific goals include:
(1) To validate the mini-VIPS performance by comparing the mini-VIPS data
retrieved during an Artic UAV mission with data retrieved from the millimeterwavelength
cloud radar (MMCR) at the Barrow ARM/CART site.
(2) To analyze mini-VIPS data to survey the properties of high latitude mixedphase
clouds
The intercomparison between in-situ and remote sensing measurements
was carried out by comparing reflectivity values calculated from in-situ
measurements with observations from the MMCR facility. Good agreement
between observations and measurements is obtained during the time frame
where the sampled volume was saturated with respect to ice. We also have
1 2
shown that the degree of closure between calculated and observed reflectivity
strongly correlates with the assumption of ice crystal geometry observed in the
mini-VIPS images. The good correlation increases the confidence in mini-VIPS
and MMCR measurements. Finally, the size distribution and ice crystal geometry
obtained from the data analysis is consistent with published literature for similar
conditions of temperature and ice supersaturation.
42
Tavares, Tiago Rodrigues. "Espectroscopia de reflectância in situ na avaliação da resposta da adubação nitrogenada em cana-de-açúcar." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-09082017-164610/.
Full textAbstract:
Na agricultura, técnicas de sensoriamento são um meio prático e barato de se obter informações sobre parâmetros de interesse agronômico, sendo os sensores ópticos uma alternativa para a avaliação da resposta de culturas agrícolas à sua adubação nitrogenada. Para a otimização da eficiência do uso de nitrogênio por culturas agrícolas, algumas estratégias de adubação se baseiam na coleta de dados espectrais em alta frequência no campo, utilizando-os para entender a variabilidade espacial do estado de nutrição da planta com este nutriente. Para a cana-de-açúcar, apesar da efetividade de sensores ópticos em idenificar alguns parâmetros desta cultura, ainda há a dificuldade de estabelecer relações com o seu Teor Foliar de Nitrogênio (TFN). Neste contexto, o presente trabalho acompanhou com sensor óptico hiperespectral (VisNIR) o desenvolvimento do dossel de cana-de-açúcar ao longo de seu ciclo, com o objetivo de avaliar temporalmente a relação entre a sua resposta espectral de reflectância e o seu TFN. Para tanto, foi avaliada uma área experimental com 28 parcelas de cana-deaçúcar, submetidas a tratamentos com diferentes doses de adubação nitrogenada. Ao longo do ciclo da cultura, avaliou-se a sua altura, o TFN e a sua resposta espectral de 400 a 900 nm; ao final do ciclo, foi estimada também a produtividade final de cada parcela. Para a avaliação do comportamento espectral da cultura em função da adubação nitrogenada e de seu desenvolvimento no campo, primeiramente, realizaramse análises de variância (ANOVA) para a altura, o TFN e as diferentes regiões espectrais e, em um segundo momento, análises descritivas e a análise de componentes principais foram conduzidas, ambas sobre os dados espectrais. Em seguida, foram aplicadas diferentes metodologias para a análise quantitativa dos espectros para a predição do TFN. Nessas análises quantitativas, buscou-se avaliar o período ideal do desenvolvimento da cana-de-açúcar para avaliações espectrais de seu TFN serem aplicadas, assim como comprimentos de onda e índices de vegetação (IVs) específicos com relações satisfatórias com o TFN. Os resultados obtidos pelo presente trabalho mostraram possível uma razoável predição do TFN da cana-de-açúcar através de espectroscopia in situ, contudo, esta avaliação só foi possível ao redor de 144 Dias Após o Corte (DAC), momento em que a cultura ainda apresentava resposta do TFN à adubação nitrogenada e no qual o dossel de plantas já estava desenvolvido o suficiente para interromper a influência do solo na leitura espectral. Os IVs avaliados que mais se destacaram para a predição do TFN utilizaram os comprimentos de onda de 490 nm da região do verde; 590 nm da região do laranja; 647 e 652 nm da região do vermelho; 730 nm da região do red-edge; 780 e 880 nm da região do infravermelho próximo. Por fim, o IV que mais se destacou foi o NDRE, índice já sugerido pela literatura com bons resultados para a determinação da biomassa da cana-de-açúcar.In agriculture, sensing techniques are a practical and inexpensive way to obtain information on agronomic parameters. Optical sensors can be used as a tool to evaluate the response of agricultural crops to nitrogen (N) fertilization. In order to optimize the efficiency of N use in agricultural crops, some fertilization strategies are based on the collection and analysis of high frequency spectral data in the field to understand the spatial variability of N status of plants. Despite the effectiveness of optical sensors in identifying some agronomic parameters of the sugarcane, establishing relations between these data and the Leaf Nitrogen Content (TFN) of the sugarcane is still quite challenging. To address this issue, in this work the development of the sugarcane canopy was monitored during its cycle with a hyperspectral optical sensor (VisNIR), with the aim of evaluating the relations between its spectral reflectance response and its TFN in time. For this, an experimental area with 28 plots of sugarcane submitted to treatments with different doses of nitrogen fertilization was evaluated. Throughout the crop year were evaluated its height, TFN and spectral response from 400 to 900 nm; at the end of the cycle, the final yield of each plot was also evaluated. To begin with, the analysis of variance (ANOVA) for height, TFN and the different spectral regions was performed to assess the spectral behavior of the crop as a function of nitrogen fertilization and its development in the field. Furthermore, a descriptive analysis and analysis of principal components were conducted, both on spectral data. In addition to this, different methodologies were applied for the spectral quantitative analysis for the prediction of TFN. The aim of these quantitative analyses was to determine the ideal period of sugarcane development in order to apply spectral evaluations of its TFN and to find specific wavelengths and Vegetation Index (IVs) with satisfactory relations with the TFN. The results obtained by the present work showed a reasonable prediction of the sugarcane TFN by in situ spectroscopy. However, this evaluation was only possible around 144 Days After Harvest (DAC). During this period, the culture showed a response of the TFN to N fertilization and the canopy of plants was already developed enough to interrupt the influence of the soil in the spectral reading. The evaluated IVs that showed better results for the TFN prediction used the wavelengths 490 nm of the green region; 590 nm of the orange region; 647 and 652 nm of the red region; 730 nm of the red-edge region and; 780 and 880 nm of the near infrared region. The IV that showed the best result for the TFN prediciton was the NDRE, vegetation index, which was already suggested by the literature with good results for the determination the sugarcane biomass.
43
Dong, Chunyu [Verfasser], and Lucas [Akademischer Betreuer] Menzel. "Assessing the availability of remote sensing, hydrological modeling and in situ observations in snow cover research / Chunyu Dong ; Betreuer: Lucas Menzel." Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://d-nb.info/1180616294/34.
Full text
44
Darlington, Eleanor F. "Meltwater delivery from the tidewater glacier Kronebreen to Kongsfjorden, Svalbard : insights from in-situ and remote-sensing analyses of sediment plumes." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/19399.
Full textAbstract:
Tidewater glaciers form a significant drainage catchment of glacierised areas, directly transporting meltwater from the terrestrial to the marine environment. Surface melt of glaciers in the Arctic is increasing in response to warmer atmospheric temperatures, whilst tidewater glaciers are also exposed to warmer ocean temperatures, stimulating submarine melt. Increased freshwater discharge not only freshens fjord waters, but also plays a key role in glacimarine sedimentary processes, transporting sediment to glacial fjords. Despite this, the temporal evolution of meltwater production, storage and release from tidewater glacier systems at seasonal and interannual time scales is poorly understood. This leaves large uncertainties in the predictions for future sea level rise, ocean circulation and the impacts on the marine ecosystem. This study focuses on Kronebreen, a tidewater glacier which flows into the head of Kongsfjorden, north west Svalbard. Surface melt produces freshwater runoff, which is discharged from the grounding line as a buoyant, sediment laden plume, which spreads laterally across the surface water. This supraglacial melt is the dominant freshwater source, contributing an order of magnitude more freshwater to Kongsfjorden, than direct submarine melting of the ice face. Calibration of MODIS band 1 satellite imagery with in situ measurements of Total Suspended Solids and spectral reflectance, provides a method to quantify meltwater and sediment discharge. Plume extent has been determined for each cloud free day, from June to September, 2002 - 2013. Analysis of plume extent with atmospheric temperature and modeled surface runoff, gives a source to sea insight to meltwater production, storage and discharge. The extent of the plume changes in response to meltwater; larger plumes form when discharge increases. These results reveal that meltwater discharge into Kongsfjorden lags atmospheric temperature, the primary driver of meltwater production, by over a week during June and July. This is reduced to only 1 - 2 days in August and September, indicating a decline in meltwater storage as the ablation season progresses, and the development of more efficient glacial drainage. Sediment plumes respond to meltwater production, making them a valuable tool for quantifying meltwater discharge from a tidewater glacier. Insights to glacier hydrology can also be obtained when surface processes are also considered. This furthers the understanding of tidewater glacier hydrology, which is valuable for improving the accuracy of sea level rise predictions.
45
Johnson, Timothy Michael. "Strain Monitoring of Carbon Fiber Composite with Embedded Nickel Nano-Composite Strain Gage." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2622.
Full textAbstract:
Carbon fiber reinforced plastic (CFRP) composites have extensive value in the aerospace, defense, sporting goods, and high performance automobile industries. These composites have huge benefits including high strength to weight ratios and the ability to tailor their properties. A significant issue with carbon fiber composites is the potential for catastrophic fatigue failure. To better understand this fatigue, there is first a huge push to measure strain accurately and in-situ to monitor carbon fiber composites. In this paper, piezoresistive nickel nanostrand (NiNs) nanocomposites were embedded in between layers of carbon fiber composite for real time, in situ strain monitoring. Several different embedding methods have been investigated. These include the direct embedding of a patch of dry NiNs and the embedding of NiNs-polymer matrix nanocomposite patches which are insulated from the surrounding carbon fiber. Also, two different polymer matrix materials were used in the nanocomposite to compare the piezoresistive signal. These nanocomposites are shown to display repeatable piezoresistivity, thus becoming a strain sensor capable of accurately measuring strain real time and in-situ. This patch has compatible mechanical properties to existing advanced composites and shows good resolution to small strain. This method of strain sensing in carbon fiber composites is more easily implemented and used than other strain measurement methods including fiber Bragg grating and acoustic emissions. To show that these embedded strain gages can be used in a variety of carbon fiber components, two different applications were also pursued.
46
Pedras, Maria Inês Machado. "Investigation of the regulation mechanisms for bioplastics production from industrial residues." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10863.
Full textAbstract:
Dissertação para obtenção do Grau de Mestre em
BiotecnologiaThe current high demand for plastics has become unsustainable. Polyhydroxyalkanoates are biopolymers stored by bacteria that can potentially replace modern plastics due to: wide range of applications; biodegradability; use of renewable resources as feedstock. High costs of current Polyhydroxyalkanoates production can be reduced using mixed cultures of organisms. Activated sludge from wastewater treatment plants is selected for Polyhydroxyalkanoates production through the imposition of cycles of intermittent feeding. In this study, the acclimation of activated sludge using synthetic volatile fatty acids (VFAs) as substrate resulted in a culture rich in Paracoccus spp. and unidentified filamentous bacteria. Low cost substrates such as sugarcane molasses (SM) or cheese whey (CW) can be employed as feedstock for further cost reduction. This requires an additional step before the microbial selection to ferment the feedstock into VFAs. In this work, the feedstock was changed from SM to CW. The population fed with SM was rich in Actinomycetaceae, while the population fed with CW was rich in Streptococcaceae, affecting the VFA composition. Consequently, the PHA-storing population and the polymer were affected. In the fermented SM (fSM) phase, the population was rich in Azoarcus (41.5 - 64.6%) and in the fCW phase the population was more diverse. Changing the pH in the fermentation reactor also affected the selection stage with an increase in Thauera and Azoarcus and a decrease in Paracoccus. A significant unidentified population of one layer sheet- forming bacteria was observed. Lastly, the occurrence of cell-to-cell communication (QS) in the selection stage was investigated. Possibly, QS molecules were detected when the carbon source was depleted. All steps of polyhydroxyalkanoate production are interconnected and for optimization, all stages must be studied and improved. Moreover, if QS proves to be involved in polyhydroxyalkanoate storage, the addition of QS molecules to the process may be explored for further optimization.
47
Nieradzik, Lars Peter [Verfasser], Adolf [Akademischer Betreuer] Ebel, and Andreas [Akademischer Betreuer] Wahner. "Four-Dimensional Variational Assimilation of Aerosol Data from In-situ and Remote Sensing Platforms / Lars Peter Nieradzik. Gutachter: Adolf Ebel ; Andreas Wahner." Köln : Universitäts- und Stadtbibliothek Köln, 2011. http://d-nb.info/1038111633/34.
Full text
48
Zhu, Ying [Verfasser], and Mark [Akademischer Betreuer] Wenig. "Citywide measurements of nitrogen dioxide (NO2) using a combination of remote sensing and in-situ measurement techniques / Ying Zhu ; Betreuer: Mark Wenig." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1169572405/34.
Full text
49
ESPINOZA, Nikolai da Silva. "Avaliação da ilha de calor urbana em Manaus com dados observados in situ e sensoriamento remoto." Universidade Federal de Campina Grande, 2017. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1429.
Full textAbstract:
Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-08-13T19:37:46Z
No. of bitstreams: 1
NIKOLAI DA SILVA ESPINOZA – DISSERTAÇÃO (PPGMET) 2017.pdf: 3187688 bytes, checksum: 3f6f29d810cd5a2c18108d0d7b68009a (MD5)Made available in DSpace on 2018-08-13T19:37:46Z (GMT). No. of bitstreams: 1 NIKOLAI DA SILVA ESPINOZA – DISSERTAÇÃO (PPGMET) 2017.pdf: 3187688 bytes, checksum: 3f6f29d810cd5a2c18108d0d7b68009a (MD5) Previous issue date: 2017-02-22
Capes
A ilha de calor urbana (ICU) é um fenômeno importante devido aos seus impactos diretos e indiretos sobre as populações humanas em ambientes urbanos. Esse fenômeno tem sido estudado amplamente usando tanto medições diretas a partir de sensores de temperatura do ar instalados em estações meteorológicas ou a bordo de veículos, como dados de temperatura da superfície medidos por sensoriamento remoto. Neste trabalho foi avaliada a variabilidade temporal e espacial da ICU na cidade de Manaus utilizando dados de precipitação, temperatura e umidade do ar em cinco estações meteorológicas distribuídas na área urbana e uma na área rural durante o período de julho de 2013 a julho de 2014. Adicionalmente, foram obtidas imagens do sensor OLI/TIRS a bordo do satélite Landsat 8 em quatro dias da estação menos chuvosa para estimar a temperatura da superfície e parâmetros de superfície, tais como o NDVI na área que estão inseridas as estações meteorológicas. Os resultados indicaram que a ICU atmosférica ocorre preferencialmente no período noturno, sendo mais intensa e condicionalmente desconfortável durante a estação seca da região. A partir das imagens de satélite, pode-se observar uma relação inversamente proporcional entre a temperatura da superfície e o NDVI, onde a maior variação de temperatura da superfície está localizada em áreas com pouca ou nenhuma vegetação.
The urban heat island (ICU) is an important phenomenon due to its direct and indirect impacts on human populations in urban environments. This phenomenon has been studied extensively using both direct measurements from air temperature sensors installed in fixed weather stations or mobile surveys using automobiles and remotely measured surface temperature data. This work evaluated the temporal and spatial variability of ICU in the city of Manaus using precipitation, temperature and air humidity data in five meteorological stations distributed in the urban area and one in the rural area during the period from July 2013 to July 2014. In addition, images of the Landsat 8 OLI / TIRS satellite were obtained in four days of the less rainy season to estimate the surface temperature in the area comprising the meteorological stations. The results indicated that atmospheric ICU occurs preferentially at night, being more intense and conditionally uncomfortable during the dry season of the region. From the satellite images, an inversely proportional relationship between the surface temperature and the NDVI can be observed, where the highest surface temperature variation is located in areas with little or no vegetation.
50
Ahmadian, Nima [Verfasser]. "Integrating Satellite Remote Sensing and In-situ Measurements to Estimate the Biophysical Parameters of Agricultural crop using Multispectral and Radar Data / Nima Ahmadian." Greifswald : Universitätsbibliothek Greifswald, 2017. http://d-nb.info/1138116963/34.
Full text