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1
Joroughi, Vahid. "Next generation multibeam satellite systems." Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/334988.
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Satellite communication will play a central role towards fulfilling next generation 5G communication requirements. As a matter of fact, anytime-anywhere connectivity cannot be conceived without the presence of the satellite segment. Indeed, satellite communication industry is not only targeting popular markets but also to high dense populated areas where the satellite will become an essential element to decongest the terrestrial wireless network.
In order to deliver broadband interactive data traffic, satellite payloads are currently implementing a multibeam radiation pattern. The use of a multibeam architecture brings several advantages in front of a single global beam transmission. First, as an array fed reflector is employed, the antenna gain to noise ratio can be increased leading to high gain in the achievable throughput. Second, different symbols can be simultaneously sent to geographically separated areas, allowing a spatially multiplexed communication. Last but not least, the available bandwidth can be reused in sufficiently separated beams, increasing the spectrum reuse in the overall coverage area. Whenever the system designers target the terabit satellite system the aforementioned multibeam architecture shall be reconsidered. Indeed, the achievable rates can be extremely increased in case a more aggressive frequency reuse is deployed and interference mitigation techniques are implemented either at the user terminal (multiuser detection) or in the transmitter (precoding).
Our study deals with the problem of precoding and linear filtering receiving methods for multibeam satellite systems when full frequency reuse is considered.
Concretely, we consider the particular restrictions of satellite communications which, in contrast to terrestrial communication systems, suffer from additional drawbacks.
First, the feeder link shall aggregate the overall data traffic leading to a very large rate requirement. This required data rate is even increased whenever linear filtering at the return link and precoding in the forward link are deployed. This is because the feed signals, which are larger than the number of beams, shall be computed on ground. In order to solve this problem, we propose a hybrid architecture where the satellite payload is equipped with a fixed processing. This on-board processing linearly transforms the received and transmitted data in order to keep the feeder link rate requirement low. The on-board processing results to be the same for both return and forward links, leading to a large reduction of the payload complexity, mass and cost.
Second, as the data traffic can be generated by different gateways, the precoding method shall be designed accordingly. In contrast to previous works, this work studies the case where the collaboration between different gateways is limited. In addition to the aforementioned contribution, in this work some unexplored aspects of multi-gateway multibeam precoding are also investigated.
Finally, we consider an important phenomena that currently needs to be treated in multibeam systems: the fact that a single codeword is embedded the information of multiple users in each beam. This leads to the difficult so-called multigroup multicast model, whose optimization requires computationally complex operations. In order to solve this problem: i) we propose a two-stage precoding design in order to both limit the multibeam interference and to enhance the intra-beam minimum user signal power, ii) a robust version of the proposed precoder based on a first perturbation model is presented. This mechanism behaves well when the channel state information is corrupted, iii) we propose a per beam user grouping mechanism so as its robust version in order to increase the precoding gain. Forth, a method for dealing with the multiple gateway architecture is presented that offers high throughputs with a low inter-gateway communication.La comunicación por satélite desempeñará un papel central en el cumplimiento de los requisitos de comunicación 5G de próxima generación. Como cuestión de hecho, la conectividad cualquier momento y lugar no se puede concebir sin la presencia del segmento satelital. De hecho, la industria de la comunicación por satélite no sólo se dirige a los mercados populares, sino también a la alta densas zonas pobladas donde el satélite se convertirá en un elemento esencial para descongestionar la red inalámbrica terrestre. Para entregar el tráfico de datos interactiva de banda ancha, las cargas útiles de satélites están implementando un diagrama de radiación de haces múltiples. El uso de una arquitectura multihaz aporta varias ventajas frente a un único haz de transmisión global. En primer lugar, como se emplea un reflector alimentado matriz, la ganancia de antena a ruido puede aumentar dando lugar a una alta ganancia en el rendimiento alcanzable. En segundo lugar, diferentes símbolos pueden ser enviados simultáneamente a las áreas separadas geográficamente, lo que permite una comunicación multiplexada espacialmente. Por último, pero no menos importante, el ancho de banda disponible puede ser reutilizado en las vigas suficientemente separadas, el aumento de la reutilización del espectro en el área de cobertura global. Cada vez que los diseñadores de sistemas se dirigen el sistema de satélites terabit se reconsideró la arquitectura multihaz mencionado. De hecho, las tasas alcanzables pueden ser extremadamente aumentaron en caso de reutilización de frecuencias más agresiva está desplegado y las técnicas de reducción de interferencias se implementan ya sea en el terminal de usuario (detección multiusuario) o en el transmisor (precodificación). Nuestros estudio aborda el problema de precodificación y filtrado lineal recibir métodos para sistemas de satélites multihaz cuando se considera la reutilización de frecuencias completa. Concretamente, consideramos las restricciones particulares de comunicaciones por satélite que, en contraste con los sistemas de comunicación terrestres, sufren de desventajas adicionales. En primer lugar, el enlace de conexión deberá agregar el tráfico global de datos que conduce a un requisito tasa muy grande. Esta velocidad de datos requerida es incluso aumentó cada vez filtrado lineal en el enlace de retorno y precodificación en el enlace directo se despliegan. Esto se debe a que las señales de alimentación, que son más grandes que el número de haces, se computarán en el suelo. Con el fin de resolver este problema, se propone una arquitectura híbrida, donde la carga útil del satélite está equipado con un procesamiento fijo. Este procesamiento a bordo transforma linealmente los datos recibidos y transmitidos con el fin de mantener el requisito de baja tasa de enlace de conexión. Los resultados del procesamiento de a bordo para ser el mismo para ambos enlaces directo y de retorno, dando lugar a una gran reducción de la complejidad de carga útil, la masa y el coste. En segundo lugar, como el tráfico de datos puede ser generada por diferentes puertas de enlace, el método de precodificación deberá ser diseñado en consecuencia. A diferencia de los trabajos anteriores, este trabajo estudia el caso en que la colaboración entre las diferentes pasarelas es limitado. Además de la contribución anterior, en este trabajo también se investigan algunos aspectos inexplorados de multi-gateway multihaz precodificación. Finalmente, consideramos un fenómeno importante que necesita actualmente para ser tratados en sistemas multihaz: el hecho de que una sola palabra de código se incrusta la información de múltiples usuarios en cada viga. Esto conduce a la denominada modelo de multidifusión multigrupo difícil, cuya optimización requiere operaciones computacionalmente complejos. En tal escenario, el diseño de precodificación en el enlace directo será dirigido.
2
Javed, M. (Muhammad). "Characterizing nonlinearity in multiantenna multibeam transmitters." Master's thesis, University of Oulu, 2017. http://jultika.oulu.fi/Record/nbnfioulu-201712053277.
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Abstract. In this thesis, effects of power amplifier (PA) distortion in multiantenna transmitter is studied. Input signal of each PA in the array is modelled by two or multiple tones to characterize the nonlinearity in terms of intermodulation distortion (IMD). In intermodulation, the phase of the nonlinearity depends on the phases of the corresponding input tones. Hence, in beamforming, progressive phase of the nonlinear components over the antenna elements creates a steered beam for the nonlinearity. Measurement setup is created to measure the phase and amplitude of the IMD components in the PA output. The theoretical polynomial relation of the IMD phase dependency on the input tones is validated by measurements. For flexible measurements, the setup is automatized by standard commands for programmable instruments.
Second part of the thesis studies the array IMD by simulations in MATLAB. The used PA model is a memoryless polynomial fitted against the measured amplitude-to-amplitude modulation and amplitude-to-phase modulation responses of a real amplifier. The effects of nonlinearity are studied by using two tones to present each independent data stream in the PA inputs. Hence, in multibeam scenario, each data stream is modelled by two tones having individual phase and amplitude depending on the beamforming coefficients of given stream. The simulations are performed in frequency domain by utilizing the concept of spectral convolution to model the intermodulation distortion, and array factor to model the far-field radiation of the linear and nonlinear PA output components. By utilizing the simulator, PA nonlinearity is analyzed in single-beam and multi-beam scenarios by varying the steering angles, allocated stream powers and amplitude distribution over the PAs. It is observed that IMD terms which depend on only one stream are steered to same direction as the linear terms whereas the IMD terms depending on both streams spreads more in space. This has potentially positive impacts on the signal-to-distortion ratio of the streams observed in beamforming directions.
3
Yu, Xiaoming. "Multibeam smart antenna systems for wireless communications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0034/NQ66298.pdf.
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Tabaddor, Mahmood M. "Nonlinear vibration of beam and multibeam systems." Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/40463.
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Parnum, Iain Michael. "Benthic habitat mapping using multibeam sonar systems." Thesis, Curtin University, 2007. http://hdl.handle.net/20.500.11937/1131.
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The aim of this study was to develop and examine the use of backscatter data collected with multibeam sonar (MBS) systems for benthic habitat mapping. Backscatter data were collected from six sites around the Australian coastal zone using the Reson SeaBat 8125 MBS system operating at 455 kHz. Benthic habitats surveyed in this study included: seagrass meadows, rhodolith beds, coral reef, rock, gravel, sand, muddy sand, and mixtures of those habitats. Methods for processing MBS backscatter data were developed for the Coastal Water Habitat Mapping (CWHM) project by a team from the Centre for Marine Science and Technology (CMST). The CMST algorithm calculates the seafloor backscatter strength derived from the peak and integral (or average) intensity of backscattered signals for each beam. The seafloor backscatter strength estimated from the mean value of the integral backscatter intensity was shown in this study to provide an accurate measurement of the actual backscatter strength of the seafloor and its angular dependence. However, the seafloor backscatter strength derived from the peak intensity was found to be overestimated when the sonar insonification area is significantly smaller than the footprint of receive beams, which occurs primarily at oblique angles. The angular dependence of the mean backscatter strength showed distinct differences between hard rough substrates (such as rock and coral reef), seagrass, coarse sediments and fine sediments. The highest backscatter strength was observed not only for the hard and rough substrate, but also for marine vegetation, such as rhodolith and seagrass. The main difference in acoustic backscatter from the different habitats was the mean level, or angle-average backscatter strength. However, additional information can also be obtained from the slope of the angular dependence of backscatter strength.It was shown that the distribution of the backscatter. The shape parameter was shown to relate to the ratio of the insonification area (which can be interpreted as an elementary scattering cell) to the footprint size rather than to the angular dependence of backscatter strength. When this ratio is less than 5, the gamma shape parameter is very similar for different habitats and is nearly linearly proportional to the ratio. Above a ratio of 5, the gamma shape parameter is not significantly dependent on the ratio and there is a noticeable difference in this parameter between different seafloor types. A new approach to producing images of backscatter properties, introduced and referred to as the angle cube method, was developed. The angle cube method uses spatial interpolation to construct a three-dimensional array of backscatter data that is a function of X-Y coordinates and the incidence angle. This allows the spatial visualisation of backscatter properties to be free from artefacts of the angular dependence and provides satisfactory estimates of the backscatter characteristics.Using the angle-average backscatter strength and slope of the angular dependence, derived by the angle cube method, in addition to seafloor terrain parameters, habitat probability and classification maps were produced to show distributions of sand, marine vegetation (e.g. seagrass and rhodolith) and hard substrate (e.g. coral and bedrock) for five different survey areas. Ultimately, this study demonstrated that the combination of high-resolution bathymetry and backscatter strength data, as collected by MBS, is an efficient and cost-effective tool for benthic habitat mapping in costal zones.
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Parnum, Iain Michael. "Benthic habitat mapping using multibeam sonar systems." Curtin University of Technology, Dept. of Imaging and Applied Physics, Centre for Marine Science and Technology, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=18584.
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The aim of this study was to develop and examine the use of backscatter data collected with multibeam sonar (MBS) systems for benthic habitat mapping. Backscatter data were collected from six sites around the Australian coastal zone using the Reson SeaBat 8125 MBS system operating at 455 kHz. Benthic habitats surveyed in this study included: seagrass meadows, rhodolith beds, coral reef, rock, gravel, sand, muddy sand, and mixtures of those habitats. Methods for processing MBS backscatter data were developed for the Coastal Water Habitat Mapping (CWHM) project by a team from the Centre for Marine Science and Technology (CMST). The CMST algorithm calculates the seafloor backscatter strength derived from the peak and integral (or average) intensity of backscattered signals for each beam. The seafloor backscatter strength estimated from the mean value of the integral backscatter intensity was shown in this study to provide an accurate measurement of the actual backscatter strength of the seafloor and its angular dependence. However, the seafloor backscatter strength derived from the peak intensity was found to be overestimated when the sonar insonification area is significantly smaller than the footprint of receive beams, which occurs primarily at oblique angles. The angular dependence of the mean backscatter strength showed distinct differences between hard rough substrates (such as rock and coral reef), seagrass, coarse sediments and fine sediments. The highest backscatter strength was observed not only for the hard and rough substrate, but also for marine vegetation, such as rhodolith and seagrass. The main difference in acoustic backscatter from the different habitats was the mean level, or angle-average backscatter strength. However, additional information can also be obtained from the slope of the angular dependence of backscatter strength.It was shown that the distribution of the backscatter. The shape parameter was shown to relate to the ratio of the insonification area (which can be interpreted as an elementary scattering cell) to the footprint size rather than to the angular dependence of backscatter strength. When this ratio is less than 5, the gamma shape parameter is very similar for different habitats and is nearly linearly proportional to the ratio. Above a ratio of 5, the gamma shape parameter is not significantly dependent on the ratio and there is a noticeable difference in this parameter between different seafloor types. A new approach to producing images of backscatter properties, introduced and referred to as the angle cube method, was developed. The angle cube method uses spatial interpolation to construct a three-dimensional array of backscatter data that is a function of X-Y coordinates and the incidence angle. This allows the spatial visualisation of backscatter properties to be free from artefacts of the angular dependence and provides satisfactory estimates of the backscatter characteristics.
Using the angle-average backscatter strength and slope of the angular dependence, derived by the angle cube method, in addition to seafloor terrain parameters, habitat probability and classification maps were produced to show distributions of sand, marine vegetation (e.g. seagrass and rhodolith) and hard substrate (e.g. coral and bedrock) for five different survey areas. Ultimately, this study demonstrated that the combination of high-resolution bathymetry and backscatter strength data, as collected by MBS, is an efficient and cost-effective tool for benthic habitat mapping in costal zones.
7
Brissette, Michel B. "The application of multibeam sonars in route survey." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29973.pdf.
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Godin, André. "The calibration of shallow water multibeam echo-sounding systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23800.pdf.
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Karam, Fouad G. "An optimal TDMA slot assignment in multibeam packet satellite systems." Thesis, University of Ottawa (Canada), 1986. http://hdl.handle.net/10393/5038.
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Artilheiro, Fernando Manuel Freitas. "Analysis and procedures of multibeam data cleaning for bathymetric charting." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23776.pdf.
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Soegiarso, Roesdiman Bishara Alfred G. "Load distribution and connection forces in multibeam precast pretopped stemmed bridges /." Connect to resource, 1989. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1137617900.
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Menon, Raghav. "Broadband, ultra-sparse array processing for low complexity multibeam sonar imaging." Thesis, University of Newcastle Upon Tyne, 2011. http://hdl.handle.net/10443/1220.
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Imaging sonar systems have become increasingly popular in numerous applications associated with underwater imaging. Though multibeam sonar systems have been used in a variety of applications, the cost of these systems limits their use. The reason for the high costs has been identified to the use of large number of hydrophone array elements and hence large number of associated analogue channels and analogue-to-digital converters (ADC) that are required in high resolution imaging. In this thesis, an imaging sonar system has been developed with as few as four array elements to minimise cost. The inter-element spacing between any two array elements was chosen to be much greater than half the wavelength. In order to avoid phase ambiguity associated with wide array element spacing, the time difference of arrival is determined. Hence, for this purpose a wideband chirp signal was used. The return signals were divided into range cells to determine the target range. The time difference of arrival was obtained by correlating the range cells. Using the time difference of arrival, the direction of arrival (DOA) angle was calculated. The image of the target being illuminated was formed using the calculated range and the DOA values. The image pixel intensity at any pixel position was determined from the correlation result between the range cells. A simulation model was built to test the theory developed. Simulations were performed for various inter-element spacing and for four different target profiles types. Two objective metrics (signal to noise (SNR) ratio and peak signal to noise (PSNR) ratio) and a subjective metric (Structural Similarity (SSIM) index) were used to determine the performance of the algorithm and image quality. Image formed from the simulations using two hydrophone elements showed the presence of artefacts in the form of correlation sidelobes. The SNR metric showed a low gain of -5dB on comparison against a test image. PSNR and SSIM ratio showed a constant image quality over all the array spacing. The number of array elements was increased and linear operation like averaging was applied. The results showed no improvement in the gain and image quality. ii To overcome the problem of correlation sidelobes, a non-linear combining process has been proposed. Using the non-linear combining process it was found that the SNR showed an average gain of 10 dB on simulated data over the images formed without it. The PSNR and SSIM also showed a small increase in the image quality. The computational complexity of the proposed non-linear combining process was calculated by determining the number of multiplications and additions. The time taken to perform these operations on a SHARC ADSP 21261 chip was calculated theoretically. The calculations showed the feasibility of using this algorithm on a digital signal processing (DSP) hardware. An experimental prototype was built and performance was tested during sea trials. The data obtained was processed using a computer. The experimental results verified that the processing algorithm was effective in a practical system.
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Bäckström, Alexander. "Sediment classification from backscatter analysis of multibeam data from Lake Vättern." Thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-117651.
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Earls, Patrick J. "New Bottom Roughness Calculation from Multibeam Echo Sounders for Mine Warfare." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/17360.
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Approved for public release; distribution is unlimitedBottom roughness has a significant effect on acoustic backscattering on the ocean bottom. Sonar systems rely on backscattering and shadows for detecting objects lying on the seafloor. The seafloor is rather complex including craters, gullies, seaweed, rocks, sand ridges, tall obstructions, deep holes and sloping regions. Underwater mines can be hidden around these objects to make detection more difficult. High resolution (1 m 1 m) seafloor data collected by the Navy using multibeam echo sounder (EM710) off the western coast of Saipan was processed by the MB Systems. The advanced least-square method is used to establish new bottom reference level from the EM710 data. After removing the reference level, the high-resolution bathymetry data converts into bottom roughness percentage using a threshold. The calculated bottom roughness percentage is ready to be incorporated into the current Navy doctrine. Two new (gradient and mathematical morphology) methods have been developed in this thesis to calculate the bottom roughness without the reference level. Statistical analysis was conducted to illustrate the added value of the new bottom roughness calculation.
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Soegiarso, Roesdiman. "Load distribution and connection forces in multibeam precast pretopped stemmed bridges." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1137617900.
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Mussai, Kushwant. "Imaging and counting of targets with a high resolution multibeam sonar." Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/11150.
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Includes abstract.Includes bibliographical references (p. 113-116).
This dissertation pertains to the development of an imaging and counting system for a high resolution multibeam sonar. A mathematical model for the operation of the multibeam sonar is derived. The computational model is developed into a simulator for the multibeam sonar in MATLAB.
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Foglia, Manzillo Francesco. "Wideband and flat multibeam antenna solutions for ultrafast communications in millimeter band." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S110/document.
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La demande toujours croissante de connectivité et de débit de données requiert une rupture dans la conception des futurs réseaux de communication et systèmes radio. Plusieurs applications émergentes en bande millimétrique, notamment les réseaux mobiles de cinquième génération (5G) et les communications satellites, exigent des antennes large bande qui assurent une grande couverture angulaire, tout en étant à la fois compactes, facilement intégrables et à bas coût.Cette thèse propose des systèmes antennaires multifaisceaux large bande et à très grande couverture angulaire, appelés «Continuous Transverse Stub Antenna» (CTS), pour réaliser un bon compromis de l’ensemble de ces objectifs. L’architecture de l’antenne comprend un réseau de fentes longues excitées par un réseau d’alimentation en chandelier, basé sur des guides d’onde à plans parallèles. Cette structure est excitée par un formateur de faisceaux quasi-optique co-intégré. La première partie du manuscrit présent des nouveaux modèles numériques qui facilitent la conception de chaque sous-système de l’antenne et permettent l’analyse des performances globales, soit en termes d’adaptation, soit en termes de diagrammes de rayonnement. Ces outils sont exploités pour la conception d’antenne et pour étudier les limites en balayage. La thèse se poursuit en présentant de nouvelles solutions technologiques et de nouveaux design pour intégrer les antennes CTS dans des modules multicouches planaires et à faible profil. La conception et la caractérisation de deux antennes intégrées en technologie LTCC pour des points d’accès 5G à 60 GHz sont discutées. L’une des deux est à faisceau fixe, l’autre est à balayage électronique, avec une couverture de ±40°, de faibles lobes secondaires et un niveau élevé de recoupement des faisceaux. Enfin, nous proposons l’association de radomes polarisants planaires à faible profil aux antennes CTS, pour réaliser des systèmes rayonnants en polarisation circulaire. Une méthodologie systématique pour la conception de polarisateurs à très large bande est présentée, ainsi qu’un design couvrant entièrement la bande Ka pour des applications satellitesThe ever-growing demand for fast and seamless connectivity shows the need of new wireless standards and technologies. Novel broadband, wide-angle scanning antennas achieving an optimal trade-off among size, gain, efficiency and costs are crucial to the development of emerging applications at millimeter waves, such as fifth-generation (5G) mobile networks and satellite communications. In this thesis, multibeam parallel-fed continuous transverse stub (CTS) array antennas are proposed as possible candidates for future mm-wave communications and are developed to tackle these requirements. The antenna architecture comprises an array of long slots, a corporate feed network based on parallel plate waveguides (PPWs) and an integrated quasi-optical beamformer. First, novel numerical models for the analysis of each subsystem and of the overall antenna, are presented, which enable an efficient and modular design of CTS antennas. These tools are exploited to derive design guidelines and assess the scanning performance. Then, novel design and technological solutions for the integration of CTS antennas in flat, low-profile multilayer modules are discussed. The design and characterization of two prototypes in LTCC technology, for 60-GHz mobile access points are presented: a fixed beam array and a switched-beam antenna with a field of view of ±40°, low SLLs and high beam overlap. Finally, planar linear-to-circular polarization converters are proposed to realize circularly polarized CTS antenna systems. A procedure to achieve an ultra-wideband, low-loss polarization conversion is outlined and a design for Ka-band satellite application is presented
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Schipilliti, Luca. "Progetto del software di acquisizione ed elaborazione dei dati di un Sonar multibeam." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21608/.
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L'obiettivo del progetto noto come SUSHI DROP è quello di realizzare un drone sottomarino AUV dotato di MBES con il relativo software di acquisizione ed altre tipologie di sistemi per la caratterizzazione geofisica, biologica e biomarina dell'ambiente subacqueo. In questo contesto il presente lavoro di tesi è volto in particolar modo allo sviluppo del software di acquisizione ed elaborazione dei dati in uscita dal sonar multibeam. Tali dati dovranno essere letti, riorganizzati, interpretati ed elaborati al fine di poter ottenere informazioni utili relative a ciò che si trova sul fondale del mar Adriatico ed alla sua morfologia tramite acquisizioni batimetriche. Inoltre sarà possibile ricavare informazioni su ciò che sta all'interno della colonna d'acqua sottostante il drone tramite acquisizioni Water Column. Questa tesi sarà quindi focalizzata sullo sviluppo del codice che dovrà effettuare tutte queste operazioni, andando a rispettare quelli che sono i vincoli imposti dal tipo di dati che vengono forniti dal dispositivo di acquisizione e le non idealità dello stesso nello svolgimento della propria funzione.
Una prima parte di questo elaborato andrà descrivere il processo di lettura ed interpretazione dei dati forniti dal MBES Sonic2020, in modo da avere un modello iniziale su cui poter lavorare per scrivere i primi algoritmi che si occuperanno della correzione dei dati e di una semplice quanto immediata rappresentazione degli stessi. Successivamente si passerà ad una fase di generazione e simulazione di dati fittizi, per poter esser certi della validità di quanto definito in precedenza. Infine verrà descritto il processo seguito per rappresentare in maniera completa i dati ottenuti dalle precedenti elaborazioni, valutando e confrontando le prestazioni di due diversi algoritmi,IDW e Kriging.
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Green, James Andrew. "Studying high-mass star formation & galactic structure through the methanol multibeam survey." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491493.
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This thesis presents the techniques and procedures that enable a new Galactic plane survey for 6668-MHz methanol masers, exclusive signposts of high-mass star formation. The statistics and properties of the largest ever sample of 6668MHz methanol masers arc detailed, including completeness and total population estimates. Through the application of rotation curves the distances are found, which then facilitates establishing the Galactic distribution of these masers, and thus of high-mass star formation regions. The relationship between these and the Spiral arms is examined. The most accurate luminosity distribution of 6668MHz methanol masers in the Galaxy and the Large Magellanic Cloud are given, together with new detections of 6668-MHz methanol and 6035-MHz hydroxyl masers in the Large Magellanic Cloud. A high spatial resolution study of an individual massive star formation region, aNI, is also presented, which not only details the precise structure and relation of methanol and excited-state hydroxyl to other species of masers for the first time, but also presents the first tentative detection of Zeeman splitting in a 6668-MHz methanol maser.
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Zhou, Zhenxiang. "Performance analysis and tracking for multibeam selection antenna array system in mobile communication." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0022/MQ51520.pdf.
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Kammerer, Edouard. "A new method for the removal of refraction artifacts in multibeam echosounder systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0034/NQ65461.pdf.
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Hestell, Filip. "Combining Sidescan Sonar and Multibeam Echo Sounder to Improve Bathymetric Resolution per Ping." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-300382.
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The master thesis degree project is carried out in the area of robotics, particularly in the area of autonomous underwater vehicles (AUV) and seafloor mapping. The goal of this degree project is to investigate if sidescan sonar data can be used to increase the bathymetric resolution. This is done on a ping-basis by using echoed intensity data from the sidescan sonar and sparse bathymetry from the lower resolution multibeam echo sounder. This ping approach can be seen as a proof of concept, with the desired outcome of being able to infer a high resolution bathymetry. An analogy of this ping approach to camera images would be to perform depth estimation per row, instead of per image. To be able to achieve this, a method for matching the sidescan with the multibeam was developed and a Multilayer Perceptron was used to infer the increased bathymetric resolution. The method relied on finding a set of sequences per ping with two bathymetric points as boundaries and sidescan sonar intensities in between those. The method needs improvement, as the results show potential but limited accuracy compared to other simpler models.Detta examensarbete är utfört inom området robotik och autonoma undervattensfarkoster, i syfte att kartlägga havsbotten. Målet för detta arbete var att undersöka huruvida sidescan sonar-data kan användas för att öka den batymetriska upplösningen. Detta görs per ping genom att använda intensitets-data från sidescan sonar och batymetri från det lågupplösta multibeam-ekolodet. Denna pingbaserade metod kan ses som ett koncepttest, där det önskade resultatet är att kunna estimera en högupplöst batymetri. Detta koncept har en analogi till djupestimering av kamerabilder, där detta skulle ske per rad istället för per bild. För att åstadkomma detta utvecklades först en metod för att matcha de två sonartyperna med varandra, där den matchade datan sedan användes för att träna en Multilayer Perceptron. Med hjälp an denna estimerades en högupplöst batymetri. Den utvecklade metoden var baserad på att hitta en mängd sekvenser per ping, där varje sekvens innehöll två batymetriska punkter vilka agerade randvärden, med tillhörande sidescan sonar-intensiteter emellan dessa. Metoden behöver förbättras då den påvisar potential, men rätt begränsade resultat jämfört med andra enklare modeller.
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Bringensparr, Caroline. "Glacial morphology and bathymetric mapping in Melville Bay, Western Greenland - Multibeam and backscatter mosaic." Thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-104797.
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During the VEGA Expedition, in June 2013, reflectivity (backscatter) and depth data wasacquired with a multibeam echosounder from an approximately 140 km2 large area in MelvilleBay, off the coast of Western Greenland. One of the expedition objectives was to search for andmap evidences of a grounded ice sheet, which is likely to have reached the edge of the continentalshelf during the Last Glacial Maximum, about 20 000 years ago. In this study, the acquired depthdata was compiled to a detailed bathymetric map, which was used to map the extension ofmorphological features caused by the ice sheet’s progression over the area. The results showbedrock erosion in the form of linear features, melt-water channels and different types ofdepressions. The surface sediment distribution, based on the reflectivity data, presents coarsersediment such as gravel in the deeper parts of the survey area as well as in channels anddepressions, while finer sediments such as silt and clay can be found generally in the remainder ofthe area. The conclusion is that the results strongly suggests there have been glacial erosion inthis area, however it is not possible to determine when this took place without age determinationof bottom samples. For a more comprehensive understanding of the glacial history in Melvilleand Baffin Bay, more surveys of this kind are necessary.Under VEGA-expeditionen, som ägde rum i juni 2013, inhämtades reflektivitets- (backscatter)och djupdata med ett multistråligt ekolod över ett cirka 140 km2 stort område i Melvillebuktenutanför kusten av västra Grönland. Ett av expeditionens syften var att söka efter och kartläggabevis för ett bottenfruset istäcke, vilket troligtvis ska ha nått ut till kontinentalsockelns yttre gränsunder det senaste glaciala maximet för cirka 20 000 år sedan. I denna studie sammanställdes deninhämtade djupdatan till en detaljerad karta över batymetrin, vilken användes för att kartläggautbredningen av morfologiska formationer orsakade av erosion kopplad till istäckets framfartöver området. Resultaten visar erosion av berggrunden i form av linjära formationer,smältvattenkanaler och olika typer av fördjupningar. Fördelningen av ytsediment, baserad påreflektivitetsdata, visar att grövre sediment som grus kan hittas i de djupare delarna avundersökningsområdet samt i kanaler och fördjupningar, medan finare sediment såsom silt ochlera påträffas generellt över resten av området. Slutsatsen som kan dras är att resultaten starktpekar på iserosion i detta område, dock är det inte möjligt att avgöra när denna ska ha skett utanåldersbestämning av bottenprover. För att få en mer heltäckande uppfattning av den glacialahistorien i Melville- och Baffinbukten krävs fler undersökningar av detta slag.
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Wittwer, Felix [Verfasser]. "Development and Study of Refractive Phase Retrieval and X-ray Multibeam Ptychography / Felix Wittwer." Hamburg : Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky, 2020. http://d-nb.info/1232915572/34.
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Galway, Robert Sean. "The integration of multibeam sonar data with Huntec sub-bottom profile data into a marine GIS." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0035/MQ65488.pdf.
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Holman, Collingwood Thain Richard. "The dynamics of a tidal intrusion front in a natural estuary : effects on multibeam sonar accuracy." Thesis, University of Plymouth, 2005. http://hdl.handle.net/10026.1/1143.
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This research has utilised high-resolution measurements of density and velocity to investigate the formation of a transient tidal intrusion front in a narrow, macrotidal estuary, and model the impact of such a frontal system on the accuracy of multibeam sonar surveys. The front was found to form during spring tides, when the barotropic inflow was sufficient to arrest the buoyant outflow from the estuary. This has been shown to be driven by changes in channel width and depth, creating a hydraulic control point. These changes in topography are demonstrated to interact with the flow m a similar manner to theoretical two-layer flow over the lee side of a sill. Enhanced shear at the density interface, provided by increasing barotropic and baroclinic flows during the flooding tide, eventually led to the decay of the frontal system. There was no surface manifestation of this front during neap tides. Further measurements have confirmed that the relatively weak barotropic flow at this time was not sufficient to overcome the stratification in a two layer regime. Frontal dynamics have been shown to conform to theoretical predictions, and an evaluation of the key frontal discrimmators has confirmed the validity of their use in such an environment. The development of a multibeam sonar refraction model has facilitated an assessment of the accuracy of hydrographic surveys conducted in the presence of a tidal intrusion fronts. Major reductions in swath width have been shown to be required when traversing a tidal intrusion front, with a flat sonar transducer array providing the most effective survey results. Undersampling the sound velocity field in the vicinity of a tidal intrusion front leads to major depth errors usmg all multibeam sonar transducer configurations; hence, accepted methods of sound velocity sampling in estuarine environments should be updated with immediate effect. Recommendations have been made that sampling in such an environment is undertaken at least hourly, at intervals of less than 50 m in order to maximise hydrographic survey efficiency.
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Nord, Robert. "Södra Mälarens innehållsrika backscatter : En studie av hur backscatterdata kan granskas, bottentypsklassificeras och utnyttjas med hjälp av GIS och statistiska metoder." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-43691.
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Sjöfartsverket har i sitt arkiv en stor mängd backscatterdata, insamlat med multibeamekolod, som ännu inte har använts till sin fulla potential. Backscatterdata innehåller information om den reflekterade signalens styrka, även kallad amplitud. Stora mängder backscatterdata kan användas för att beskriva den akustiska bottenreflektionen. Syftet med denna undersökning är att beskriva hur variationen för amplituden varierar beroende på vilken bottentyp den reflekteras ifrån. En metod för att skapa rasterdataset med bottenhårdhet och bottentyp baserat på amplituddata ska utvecklas. Resultaten från denna metod ska sedan jämföras med kartdata från Sveriges Geologiska Undersökning (SGU). Totalt användes cirka 45 miljoner bottenpunkter i studieområdet. Varje punkt innehåller information om amplitud som systemet har registrerat från det reflekterade ekot. Dessa data behövde genomgå databehandlingar, bl.a. en vinkelkorrigering som ger ett mer trovärdigt värde av amplitud. Med hjälp av befintlig information om studieområdets sjöbotten i form av en maringeologisk karta från SGU, kunde amplitud från ett antal specifika uppskattade bottentyper studeras direkt. Resultatet uppvisar stora skillnader i amplitudens variationer. Specifika medelvärden och standardavvikelser kan urskiljas beroende av vilken specifik uppskattad bottentyp som studerades. ”Mjuk lera” gav en svagare signal med relativt låg standardavvikelse. ”Häll” och ”sten och block” reflekterade en liknade men starkare signal. Amplitudata från backscatter-informationen i hela datamängden utnyttjades för att skapa raster vars syfte var att beskriva den uppskattade bottenhårdheten. Olika raster skapades med olika parametrar beroende på ändamål. Gemensamt för alla skapade raster är att de är uppbyggda med metoden ”flytande beräkning” som möjliggjorde en mer utjämning. Resultatet av medelvärde och standardavvikelse från varje enskild bottentyp utnyttjades för att utföra en klassning av bottentyper på ett skapat raster lämpad för just bottentypsklassificering. För att få ett mer noggrannare medelvärde och standardavvikelse studerades ett 68 % konfidensintervall för de olika bottentyperna. De bottentyper som valdes för klassningen var ”mjuk lera”, ”sand, grus och sten”, ”häll”, ”sten och block” och även ”lägre amplituder”. ”Häll” och ”sten och block” klassades samma eftersom deras fysikaliska egenskaper gör att deras värden ligger nära varandra vilket gjorde det svårt att urskilja dem.”Lägre amplituder” utnyttjades för att identifiera områden som har lägre reflektionsförmåga än mjuk lera. Vilken bottentyp det är kan endast provtagning ge svar på. Med hjälp av tolkning av skapade raster och den maringeologiska kartan så korrigerades intervallen och användes som klassning. Resultatet från klassningen visar tydligt att områden kan urskiljas i kartbilden. Majoriteten av klassningarna resulterade i typen mjuk lera. En jämförelse av klassningen med den maringeologiska kartan visar att stora skillnader finns mellan dem. Mjuk lera gav en överensstämmelse på 86 %, sand, grus och sten 30 % och häll, sten och block 52,5 %, vilket gav en total överenstämmelse på 56,2 %. Jämförelse utfördes även med 9 provtagningspunkter som fanns tillgängliga i området. Det visade en total överenstämmelse på 89 %. Undersökningen visar att amplitud från havsbottnen korrelerar med bottentypen det är. Noterbart är att metoden för bottentypsklassificering som utvecklats i denna studie inte har kunnat kvalitetsgranskas med ett trovärdigt resultat, p.g.a. av statistiskt för få provtagningspunkter att jämföra mot. Studien visar dock att med mer data och noggrannare referensdata kan en mer automatisk klassningsmetod utvecklas.The Swedish Maritime Administration (Sjöfartsverket) has a large amount of backscatter data collected with multibeam echosounder in their archive that has not been fully used despite its great potential. Backscatter data contains information about the strength of the reflected signal, often called amplitude strength. Large amounts of backscatter data could be used to describe the acoustic bottom reflection. The purpose of this study is to describe how the variation of the amplitude strength varies dependent on which estimated bottom types the data reflects from. Also a method will be produced which purpose is to create gridded dataset of estimated bottom hardness and bottom type based on amplitude data and compare this method with official data from the Geological Survey of Sweden (SGU).A total number of 45 million depths (data points) were used in the study area. Every data point contains information about the amplitude strength that the system has recovered from the reflective echo. This data needed to be preprocessed, including an angle correction that produces a more reliable value of the amplitude strength. With existing information about the bottom from the study area, in this case a marine geological map from SGU, the amplitude from some estimated specified bottom types could be studied. The result shows differences in their variation. Specific values of mean and standard deviation could be distinguished by which estimated specific bottom types that were studied.The amplitude strength from the backscatter information of the complete data set was used to create a raster that describes the estimated bottom-hardness. Different raster were created with various parameters dependent on the purpose. All of the created raster data had in common that it was created using a technique called “flow calculation” which result in more equalization.The mean and standard deviation for every individual estimated bottom type were used to create interval for classification of the bottom types. To achieve a more accurate estimation of the mean and standard deviation for the bottom types, a 68 % confidence interval were used. The classes that were chosen for classification was “soft clay”, “sand, gravel and stone”, “solid rock”, “stone and block” and “lower amplitudes”. “Solid rock” and “stone and block” were combined in the same class because of their similar physical properties. “Lower amplitudes” were chosen in order to indicate areas where the amplitude strength from the reflective echo was lower than “soft clay”.The result of the intervals was adjusted by an examination of the raster data and the marine geological map and was then used for classification.The result from the classification shows that areas of different bottom types could be distinguished in the map. The majority of the classification was of the type “soft clay”. A comparison between the classification and the marine geological map showed some differences. “Soft clay” matched with 86 %, “sand, gravel and stone” 30 %, “solid rock, stone and block” 52,5 % and the total matched with 56,2 %. Comparisons between 9 samplings in the area were made. The result shows that the classification-accuracy is 89 %.The study shows that the amplitude strength correlates to the bottom type. Note that too few samplings for bottom classification were used in the study and thus the results are not fully reliable. The study, however, shows that with larger amount of data and more accurate reference data a better automatic classification method could be developed.
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Diallo, Cheikh-Dieylar. "Study and design of new multibeam antenna architectures in Ku and Ka bands for broadband satellite applications." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S151/document.
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Les antennes multifaisceaux (AMFs) sont cruciales pour les applications de télécommunications par satellite modernes et futures, civiles et militaires. La partie basse du spectre électromagnétique est saturée alors que de larges bandes de fréquences sont disponibles dans la bande Ka, dans laquelle des missions à très-haut débit ont émergées au cours de la dernière décennie. La tendance consiste à réduire la taille des spots pour les couvertures multi-spots afin de diminuer le prix des satellites. Ainsi des antennes d’ouverture de plus en plus grande électriquement sont requises, induisant des ruptures technologiques majeures. Les lentilles de Luneburg insérées dans un guide d’ondes à plans parallèles (GOPP) deux plaques métalliques parallèles (PMPs) sont des solutions attractives pour illuminer les AMFs, puisqu’elles peuvent aboutir à des formateurs de faisceaux de bande et champ de visée larges, pertes et coûts faibles, et simples à concevoir, réaliser et intégrer. Les travaux de cette thèse portent sur le développement de nouvelles méthodes d’implémentation et sur la conception de AMFs à base de lentille de Luneburg. La réalisation de la lentille de Luneburg est connue pour être un défi technologique majeur. Un état de l’art des méthodes de réalisation est fourni. Ensuite, deux nouvelles méthodes sont proposées, ainsi qu’une méthode et des outils de conception. La première méthode de réalisation consiste en une matrice périodique et régulière de plots métalliques de taille inférieure à la longueur d’onde, et où la séparation du GOPP varie. La hauteur des plots et la séparation du GOPP contrôlent la valeur de l’indice de réfraction équivalente. L’antenne à 9 faisceaux tout métal conçue, fabriquée et mesurée, comporte 8314 plots et présente d’excellentes performances, notamment meilleures que sa version à séparation de plaques constante. La seconde méthode de réalisation consiste en une matrice périodique et régulière de trous circulaires de taille inférieure à la longueur d’onde réalisés sur un des deux revêtements cuivrés d’un substrat diélectrique plus une plaque métallique supérieure séparée du plan des trous par une couche d’air d’épaisseur fixe. L’antenne à 5 faisceaux conçue comporte 2696 trous et présente de très bonnes performances comparés à ces semblables dans la littératureMulti-beam antennas (MBAs) are crucial to modern and future, civilian and military satellite telecommunications applications. The low part of the electromagnetic spectrum is congested, while wide band of frequencies are available in the Ka-band, in which broadband missions have emerged in the last decade. The trend is reducing the size of spots in multi-beam coverage to reduce the cost of satellites, hence more electrically large antennas are needed, with major technological breakthrough as a consequence. Luneburg lenses in parallel-plate waveguide (PPW) are attractive solutions to excite MBAs, since they could lead to wide band and field-of-view, low loss and cost, easy to design, manufacture and accommodate Beam Forming Networks. This PhD deals with the development of novel implementations and the design of broadband, low loss and wide field-of-view Luneburg lens based MBAs. The implementation of the Luneburg lens is known as a major technological challenge. A state-of-the art of the implementation techniques is presented. Then two novel implementations of Luneburg lens in PPW environment are proposed, like design method, process and tools. The first implementation consists of a periodic and regular array of subwavelength vertical metal posts, where the PPW spacing is variable. The post height and PPW spacing modulate the equivalent refractive index. The all-metal 9-beams antenna designed, manufactured and measured, has 8314 posts and shows excellent performances, better than the traditional constant PPW spacing version. The second implementation consists of periodic and regular array of subwavelength circular holes etched on the copper cladding of a dielectric substrate with an air gap between the holes plane and the PPW top plate. The radius of the holes control the equivalent index. The 5-beams antenna designed has 2696 holes and shows very good performances as compared to similar devices in literature
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Haselmaier, Lawrence H. "Computation of a Virtual Tide Corrector to Support Vertical Adjustment of Autonomous Underwater Vehicle Multibeam Sonar Data." ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/2080.
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One challenge for Autonomous Underwater Vehicle (AUV) multibeam surveying is the limited ability to assess internal vertical agreement rapidly and reliably. Applying an external ellipsoid reference to AUV multibeam data would allow for field comparisons. A method is established to merge ellipsoid height (EH) data collected by a surface vessel in close proximity to the AUV. The method is demonstrated over multiple collection missions in two separate areas. Virtual tide corrector values are derived using EH data collected by a boat and a measured ellipsoid to chart datum separation distance. Those values are compared to measurements by a traditional tide gauge installed nearby. Results from the method had a mean difference of 6 centimeters with respect to conventional data and had a mean total propagated uncertainty of 15 centimeters at the 95% confidence interval. Methodologies are examined to characterize their accuracies and uncertainty contribution to overall vertical correction.
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Keeton, Jane A. "The use of image analysis techniques to characterise mid-ocean ridges from multibeam and sidescan sonar data." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/1620/.
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Braker, Benjamin M. "Spatial-spectral processing for imaging systems: Multibeam RF imaging and radar systems using spectral hole burning materials." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3337181.
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Pota, Zainab Abbas. "Simulation Analysis of Quality of Service Parameters for On-board Switching on ATM Network for Multimedia Applications." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1289802401.
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Beyer, Andreas. "Seafloor analysis bsed on multibeam bathymetry and backscatter data = Meeresbodenanalyse auf der Basis von Bathymetrie und akustischer Rückstreuung /." Bremerhaven : Alfred-Wegener-Institut für Polar- und Meeresforschung, 2006. http://www.loc.gov/catdir/toc/fy0711/2007403021.html.
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Beyer, Andreas. "Seafloor analysis based on multibeam bathymetry and backscatter data = Meeresbodenanalyse auf der Basis von Bathymetrie und akustischer Rückstreuung /." Bremerhaven : Alfred-Wegener-Inst. für Polar- und Meeresforschung, 2006. http://www.loc.gov/catdir/toc/fy0711/2007403021.html.
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Conti, Matteo. "Studio morfo-batimetrico dei canali distributori del delta del Po di Pila." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8247/.
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In questa tesi sono state analizzate, a partire da dati batimetrici ad alta risoluzione ottenuti tramite tecnologia multibeam, le morfologie caratteristiche dei tre canali tributari del Delta del Po di Pila: Busa di Dritta, Busa di Tramontana, Busa di Scirocco. Lo studio è stato effettuato col software Global Mapper, che ha permesso la mappatura e l’analisi morfometrica dei principali elementi morfologici osservati, ovvero aree depresse, zone con presenza di forme di fondo, zone a fondo piano e depositi da instabilità gravitativa sulle sponde dei canali. La loro distribuzione nei vari tratti dei canali è stata messa in relazione alle caratteristiche morfologiche e idrauliche del tratto fluviale e ai processi erosivi e deposizionali che interessano i tre canali ad intensità variabile, nell’ambito dell’evoluzione molto recente di questa porzione del delta. I risultati di questo studio indicano come l’utilizzo in ambito fluviale delle più recenti tecniche di acquisizione dei dati batimetrici multibeam possa costituire la base per un dettagliato studio delle morfologie fluviali e delle dinamiche ad esse associate.
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Wolfson, Monica L. "Multibeam Observations of Mine Scour and Burial near Clearwater, Florida, Including a Test of the VIMS 2D Mine Burial Model." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001197.
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Firetto, Carlino Marco. "Evoluzione tardo-pleistocenica ed olocenica dell'offshore di Augusta (SR) tramite interpretazione di dati geofisici (Swath Bathymetry, Side Scan Sonar, Sub-bottom Chirp) e analisi di pozzi nei settori emersi." Thesis, Universita' degli Studi di Catania, 2011. http://hdl.handle.net/10761/112.
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Lo studio proposto consiste nella definizione dei caratteri morfo-strutturali e dell'evoluzione stratigrafica tardo-pleistocenica ed olocenica dei settori sommersi del golfo di Augusta (SR), ubicato lungo il litorale ionico del Plateau Ibleo (Sicilia sud-orientale). Lo studio e' stato effettuato principalmente tramite la creazione e la successiva interpretazione di un ampio database, che deriva essenzialmente dalla sovrapposizione di dati geofidici di elevata risoluzione (Multibeam, Side Scan Sonar, Sub-bottom Chirp). Il tentativo di correlare gli elementi riconosciuti nelle aree sommerse con i corrispondenti a terra, e' stato possibile grazie anche al confronto con l'ampia cartografia disponibile per il settore in esame e con la stratigrafia di nove pozzi, realizzati ai fini di emungimento delle acque di sottosuolo, lungo le aree costiere. Sono state in questo modo definite le caratteristiche morfologiche della piattaforma continentale, le modalita' di prosecuzione dell'assetto strutturale del graben di Augusta nei corrispettivi settori sommersi e l'assetto stratigrafico relativo ai depositi tardo-pleistocenici ed olocenici.The proposed study outlines the morphological and structural features of the offshore area concerning the Augusta Bay (located along the Eastern sector of the Hyblean Plateau, south-eastern Sicily, Italy) proposing its Late-Pleistocene and Olocene structural and stratigraphical evolution, mostly through the interpretation of geophysical data. In addiction, by considering the previous works carried out on the emerged sectors of the study area and the stratigraphy of nine wells it was possible to undestand the offshore prosecution of the structural pattern of the emerged areas and the Late-Pleistocene and Olocene stratigraphical features.
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Innangi, Sara <1976>. "Analisi del segnale di backscatter da Ecoscandaglio MultiFascio (EMF) in ambiente marino : applicazioni per lo studio dei fondali e delle risorse ittiche pelagiche in 3D." Doctoral thesis, Università Ca' Foscari Venezia, 2014. http://hdl.handle.net/10579/4660.
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L’ambiente marino viene tradizionalmente suddiviso in un dominio bentonico e in un dominio pelagico; in questo lavoro di tesi è stato utilizzato l’Ecoscandaglio MultiFascio (EMF), per investigarli entrambi, utilizzando la risposta acustica (backscatter) dell’onda emessa. E’ stato così applicato lo studio del backscatter in due ambiti scientifici, apparentemente separati tra loro: uno più geologico-sedimentologico e uno più biologico. In particolare, sono state utilizzate nuove metodiche di elaborazione del segnale acustico che hanno portato a nuovi campi di studio e che pongono le basi per successive indagini e ricerche. Lungo il litorale tirrenico lucano il backscatter è stato utilizzato per la caratterizzazione del fondale marino in termini di facies acustiche, mentre lungo la piattaforma continentale dello Stretto di Sicilia è stata analizzata la risposta acustica dell’intera colonna d’acqua per lo studio dei banchi di pesci in tre dimensioni. I risultati hanno portato, in ambito geologico, alla realizzazione di una carta tematica molto dettagliata, oltre che alla creazione di un mosaico acustico in grado di restituire informazioni tessiturali del fondo altamente discriminanti. In ambito biologico le nuove metodiche applicate hanno consentito di visualizzare e descrivere in tre dimensioni i banchi di pesci più abbondanti (Engraulis encrasicolus, Sardina pilchardus) di cui è stata fatta un’analisi della forma, della grandezza e dei volumi.
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Flinders, Ashton. "Evaluation of artic multibeam sonar data quality using nadir crossover analysis and complication of a full-resolution data product." Thesis, University of New Hampshire, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1526061.
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Sterling, David L. "A Comparison of Spatial Interpolation Techniques for Determining Shoaling Rates of the Atlantic Ocean Channel." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/35072.
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The United States of Army Corp of Engineers (USACE) closely monitors the changing depths of navigation channels throughout the U.S. and Western Europe. The main issue with their surveying methodology is that the USACE surveys in linear cross sections, perpendicular to the channel direction. Depending on the channel length and width, these cross sections are spaced 100 - 400 feet apart, which produces large unmapped areas within each cross section of a survey.
Using a variety of spatial interpolation methods, depths of these unmapped areas were produced. The choice of spatial interpolator varied upon which method adequately produced surfaces from large hydrographic survey data sets with the lowest amount of prediction error. The data used for this research consisted of multibeam and singlebeam surveys. These surveys were taken in a systematic manner of linear cross-sections that produced tens of thousands of data points.
Nine interpolation techniques (inverse distance weighting, completely regularized spline, spline with tension, thin plate spline, multiquadratic spline, inverse multiquadratic spline, ordinary kriging, simple kriging, and universal kriging) were compared for their ability to accurately produce bathymetric surfaces of navigation channels. Each interpolation method was tested for effectiveness in determining depths at "unknown" areas. The level of accuracy was tested through validation and cross validation of training and test data sets for a particular hydrographic survey.
By using interpolation, grid surfaces were created at 15, 30, 60, and 90-meter resolution for each survey of the study site, the Atlantic Ocean Channel. These surfaces are used to produce shoaling amounts, which are taken in the form of volumes (yd.3). Because the Atlantic Ocean Channel is a large channel with a small gradual change in depth, a comparison of grid resolution was conducted to determine what difference, if any, exists between the calculated volumes from varying grid resolutions. Also, a comparison of TIN model volume calculations was compared to grid volume estimates.
Volumes are used to determine the amount of shoaling and at what rate shoaling is occurring in a navigation channel. Shoaling in each channel was calculated for the entire channel length. Volumes from varying grid resolutions were produced from the Atlantic Ocean Channel over a seven-year period from 1994-2001.
Using randomly arranged test and training datasets, spline with tension and thin plate spline produced the mean total error when interpolating using singlebeam and multibeam hydrographic data respectively. Thin plate spline and simple kriging produced the lowest mean total error in full cross validation testing of entire singlebeam and multibeam hydrographic datasets respectively.
Volume analysis of varying grid resolution indicates that finer grid resolution provides volume estimates comparable to TIN modeling, the USACE's technique for determining sediment volume estimates. The coarser the resolution, the less similar the volume estimates are in comparison to TIN modeling. All grid resolutions indicate that the Atlantic Ocean Channel is shoaling. Using a plan depth of 53 feet, TIN modeling displayed an annual average increase of 928,985 cubic yards of sediment from 1994 - 2001.
Master of Science
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MARCHESE, FABIO. "A geomorphometric approach to assess multi-scale spatial distribution and geomorphological characterization of benthic habitats." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2016. http://hdl.handle.net/10281/103697.
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Quantitative analysis on Digital Elevation Models (DEMs) are rarely conducted on submarine landscapes. Only recently the application of quantitative geomorphometric techniques to the bathymetry data set has been effectively tested and the authors demonstrated their utility in improving the geological interpretation of submarine environments. In this thesis geomorphometric analytical techniques were applied to a high-resolution bathymetry data set acquired along three different survey areas located on the Apulian continental margin, between 5 and 1400m of water depth. We focused our analysis on a supervised computation of the most significant morphometric parameters that typify the surveyed areas to automatically select those seafloor geomorphologies that appear to be linked with occurrences of specific benthic habitats. The work has been done in order to figure out relationships between the observed morphologies and the associated habitat distribution. The objective identification of morphologic features represents indeed a significant step in defining spatial units that are related to geomorphological processes. Our study aims at highlighting the importance of combining acoustic survey techniques and geomorphometric analysis to successfully support a preliminary quantitative assessment of habitats distribution and extent. Our method was specifically designed for the study areas and allowed the identification of a geomorphological proxy (based on geomorphometric parameters) associated with the benthic habitats distribution. The approach should offer an efficient and cost-effective technique for supporting the growing global need for better spatial management within the Mediterranean marine environment.
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Brizzolara, Jennifer L. "Characterizing Benthic Habitats Using Multibeam Sonar and Towed Underwater Video in Two Marine Protected Areas on the West Florida Shelf, USA." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6806.
Full textAbstract:
This study investigates a way to characterize the geology and biology of the seafloor in two Marine Protected Areas on the West Florida Shelf. Characterization of benthic habitats needs to include sufficient detail to represent the complex and heterogeneous bottom types. Characterizations can be interpreted from multiple data sets and displayed as benthic habitat maps. Multibeam sonar bathymetry and backscatter provide full spatial data coverage, but interpretation of such data requires some form of ground truth (to characterize the habitat). Imagery from towed underwater video provides continuous transects of seafloor data, which provide a more efficient method than data from sediment grabs, stationary cameras, or video from slow-moving remotely-operated vehicles while a ship is on station.
Two Marine Protected Areas, Steamboat Lumps and Madison-Swanson, were previously mapped by the USGS using a 95 kHz multibeam sonar system. Researchers at the University of South Florida, using a 300 kHz high-resolution multibeam sonar in 2002 and a 400 kHz high-resolution multibeam sonar in 2016, filled in the northeast triangular portion of Madison-Swanson. Bathymetry and backscatter data were compared to towed underwater-video observations. A modified version of the Coastal and Marine Ecological Classification Standard (CMECS), utilizing a scale-based hierarchy, was used for habitat characterization of video images. Identifiers from the geoform and substrate components of CMECS, as well as substrate-influencing biologic components, were characterized using still images at 15-second intervals from towed underwater video collected using the Camera-Based Assessment Survey System (C-BASS). These characterizations were then georeferenced (located in three-dimensional space) for comparison with bathymetry and backscatter data.
In Steamboat Lumps, eight substrate variations were identified from video, while in Madison-Swanson 27 substrate variations were identified, including many combinations of hard and soft substrate types. Four new hard-bottom textures are identified from video in Madison-Swanson: exposed high-relief, moderate-relief, and low-relief hard bottom, as well as covered low-relief hard bottom identified by the presence of attached biota. Hard- and mixed-bottom substrate types identified from video are more heterogeneous than can be resolved from 95 kHz Kongsberg EM 1002 multibeam sonar bathymetry and beam-averaged backscatter. However, in soft bottom areas, more changes are evident in beam-averaged backscatter than are visible in video, though this may be attributed to changes in sonar settings. This does not appear to be the case with high-resolution and ultra-high resolution multibeam sonars, such as the 300 kHz Kongsberg EM 3000 and the 400 kHz Reson SeaBat 7125, which can use time-series rather than beam-averaged backscatter. Analyses of the multibeam bathymetry data indicate that 94.5% of Steamboat Lumps is “flat” (slope < 5°) versus “sloping” for the remaining area (5° < slope < 30°). Only 87% of Madison-Swanson is “flat” versus “sloping”. Both marine protected areas have very low rugosity, i.e., the surface of the seafloor is nearly planar.
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Ilich, Alexander Ross. "Integrating Towed Underwater Video with Multibeam Acoustics for Mapping Benthic Habitat and Assessing Reef Fish Communities on the West Florida Shelf." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7525.
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Using a towed underwater video camera system, benthic habitats were classified along transects in a popular offshore fishing area on the West Florida Shelf (WFS) known as “The Elbow.” Additionally, high resolution multibeam bathymetry and co-registered backscatter data were collected for the entire study area. Using these data, full coverage geologic and biotic habitat maps were developed using both unsupervised and supervised statistical classification methodologies. The unsupervised methodology used was k-means clustering, and the supervised methodology used a random forest algorithm. The two methods produced broadly similar results; however, the supervised methodology outperformed the unsupervised methodology. The results of the supervised classification demonstrated “substantial agreement” (κ>0.6) between observations and predictions for both geologic and biotic habitat, while the results of the unsupervised classification demonstrated “moderate agreement” (κ>0.4) between observations and predictions for both geologic and biotic habitat. Comparisons were made with the previously existing map for this area created by Florida Fish and Wildlife Conservation Commission’s Fish and Wildlife Research Institute (FWC-FWRI). Some features are distinguishable in both maps, but the FWC-FWRI map shows a greater extent of low relief hard bottom features than was predicted in our habitat maps. The areas predicted as low relief hard-bottom by FWC-FWRI often coincide with areas of higher uncertainty in the supervised map of geologic habitat from this study, but even when compared with ground-truth points from the towed video rather than predictions, the low relief hard bottom in FWC-FWRI’s map still corresponds to what was identified as sand in the video 73% of the time. The higher uncertainty might be a result of the presence of mixed habitats, differing morphology of hard-bottom, or the presence of sand intermixed with gravel or debris. More ground-truth samples should be taken in these areas to increase the confidence of these classifications and resolve discrepancies between the two maps.
Data from the towed video system were also used to assess differences in fish communities among habitat types and to calculate habitat-specific densities for each taxa. Fish communities were found to significantly differ between soft and hard bottom habitats as well as among the hard-bottom habitats with different vertical relief (flat hard-bottom vs more steeply sloping areas). Additionally, significant differences were found between the fish communities in habitats with attached fauna such as sponges and gorgonians, and areas without attached fauna; however, attached fauna require rock to attach to and the rock habitats rarely lacked attached fauna, so this difference may just reflect the difference between fish communities in sand and rock habitats without the consideration of vertical relief. Moreover, the species driving the differences in the fish communities were identified. Fish were more likely to be present and assemblages were more species rich in more complex habitats (rockier, higher relief, presence of attached fauna). Habitat specific densities were calculated for each species, and general trends are discussed.
Lastly the habitat-specific densities were extrapolated to the total area of habitat type (sand vs rock) as predicted by the supervised geologic habitat map. There is predicted to be approximately 111,000 fish (95% CI [67015, 169405]) within the study area based on this method, with ~47,000 (~43%) predicted to be within the sand habitat and ~64,000 (~57%) in the rock habitat. This demonstrates the potential of offshore rocky reefs as “critical habitats” for demersal fish in the offshore environment as rock accounts for just 4% of the study area but is expected to contain over half of the total abundance. The value of sand habitats is also shown, as due to their large area they are able to contribute substantially to the total number of fish despite sustaining comparatively low densities.
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Genel, Kerim, and Jörgen Andersson. "3D-visualization of fairway margins, vessel hull versus depth data." Thesis, University of Gävle, Department of Technology and Built Environment, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-232.
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Fledermaus is software where different kind of analysis with spatial data can be done. The main area where to use Fledermaus is related to hydrographical surveys. This study is aimed to test and analyse the way Swedish Maritime Administration (Sjöfartsverket) uses Fledermaus. Through step by step explaining how to do when measuring sea bed conditions from a vessel, this text is possible to use as a manual for the applications that are mentioned in this report.
Another thing that is treated is the squat effect that belongs to vessel dynamic motions. Test of visualization that concerning squat in Fledermaus is done, but with a negative result when squat in a perspective to show motions in height that can be up to about a metre is very hard in a terrain model of thousands of metres. By further tests by arranging the input data, several interesting diagrams have been created through Microsoft Excel where graphs show that the depths are affecting the squat effect. This is showed in same diagram but with two different scales to show the relationship between how a point at the vessel moves in height compared to the depth under the vessel when the vessel is navigating in the sea.
Fledermaus är en programvara där olika analyser med rumsliga data kan genomföras. Största användningsområdet är att använda Fledermaus till mätningar som är relaterade till sjömätning. Den här studien är inriktad till att testa och analysera applikationer som Sjöfartsverket använder sig av i Fledermaus. Genom att steg för steg förklara hur Fledermaus ska användas när bottenförhållanden ska mätas sett från ett fartyg, så blir texten även möjlig att använda som en manual till de applikationer i Fledermaus som är nämnda i denna rapport.
Det andra som behandlas är squateffekten som tillhör ett fartygs dynamiska rörelser. Test av visualisering som behandlar squat i Fledermaus är genomförd, dock med negativt resultat då squat i ett perspektiv med att visa rörelser i höjd som kan uppgå till runt en meter är väldigt svårt i en terrängmodell som sträcker sig tusentals meter. Dock genom vidare tester genom behandling av indata, har flertalet intressanta diagram skapats genom Microsoft Excel där kurvor visar att djupet inverkar på squateffekten. Detta visas genom att i samma diagram fast med två olika skalor visa förhållandet mellan hur en punkt på båten rör sig i höjd jämfört med att djupet under fartyget ändras då fartyget gör fart genom vattnet.
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Stellino, Sabrina. "Mappatura degli habitat e degli oggetti antropici della laguna di Venezia." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9602/.
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L’utilizzo del Multibeam Echo sounder (MBES) in ambienti di transizione poco profondi, con condizioni ambientali complesse come la laguna di Venezia, è ancora in fase di studio e i dati biologici e sedimentologici inerenti ai canali della laguna di Venezia sono attualmente scarsi e datati in letteratura.
Questo studio ha lo scopo di mappare gli habitat e gli oggetti antropici di un canale della laguna di Venezia in un intervallo di profondità tra 0.3 e 20 m (Canale San Felice) analizzando i dati batimetrici e di riflettività (backscatter) acquisiti da ISMAR-Venezia nell’ambito del progetto RITMARE. A tale scopo il fondale del canale San Felice (Venezia) è stato caratterizzato dal punto di vista geomorfologico, sedimentologico e biologico; descrivendo anche l’eventuale presenza di oggetti antropici.
L’ecoscandaglio utilizzato è il Kongsberg EM2040 Dual-Compact Multibeam in grado di emettere 800 beam (400 per trasduttore) ad una frequenza massima di 400kHZ e ci ha consentito di ricavare ottimi risultati, nonostante le particolari caratteristiche degli ambienti lagunari.
I dati acquisiti sono stati processati tramite il software CARIS Hydrographic information processing system (Hips) & Sips, attraverso cui è possibile applicare le correzioni di marea e velocità del suono e migliorare la qualità dei dati grezzi ricavati da MBES. I dati sono stati quindi convertiti in ESRI Grid, formato compatibile con il software ArcGIS 10.2.1 (2013) che abbiamo impiegato per le interpretazioni e per la produzione delle mappe.
Tecniche di ground-truthing, basate su riprese video e prelievi di sedimento (benna Van Veen 7l), sono state utilizzate per validare il backscatter, dimostrandosi molto efficaci e soddisfacenti per poter descrivere i fondali dal punto di vista biologico e del substrato e quindi degli habitat del canale lagunare. Tutte le informazioni raccolte durante questo studio sono state organizzate all’interno di un geodatabase, realizzato per i dati relativi alla laguna di Venezia.
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Zubalich, Riccardo. "Processi morfo-sedimentari attivi alla foce del Po di Pila da rilievi batimetrici multi-temporali." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14040/.
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In questo studio, i dati batimetrici ad altissima risoluzione utilizzati hanno permesso di condurre un’analisi bati-morfologica di dettaglio sui fondali del Po della Pila, con approccio multi-temporale a scala delle variazioni inter-annuali recenti (2013-2016). La tesi è focalizzata sull’interazione dinamica di diversi processi morfo-sedimentari, sia fluviali sia marini, che interessano i fondali del delta sommerso e si manifestanoo nella sua morfologia attuale. Attraverso il confronto con cartografie storiche e dati batimetrici del XIX e XX secolo, la dinamica evolutiva osservata è stata inquadrata in un più ampio contesto temporale. Infine, è stato considerato qualitativamente il possibile impatto delle attività umane sul bacino idrografico e sulle dinamiche evolutive osservate.
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Saleem, Shihadah M. "Geomorphology of Submarine Spring West of Fort Myers, Florida." Scholar Commons, 2007. http://scholarcommons.usf.edu/etd/3836.
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In March of 2000, March of 2001, and April of 2002, multibeam bathymetry and backscatter data were collected, which revealed several low-temperature hydrothermal submarine springs in the Mudhole Submarine Springs (MHSS) area that were investigated by SCUBA divers. High-resolution multibeam sonar provides a precise way of defining the geomorphology of the seafloor. The bathymetry data were used to understand (1) vent geomorphology and how it varied from vent to vent; (2) spatial patterns of active vents compared to extinct vents and known land springs identified by Kohout (1977) and Breland (1980); and (3) potential correlations between geochemical and geomorphological characteristics of the vents in the study area. SCUBA observations show that MHSS, Spring #3, New Spring, Northern Rusty, Rusty, and Near Rusty are active springs, while Dormant Spring and Sinister Spring were extinct or inactive at the time of the March 2001 cruise.During the April 2002 cruise the locations of Rusty Spring, New Spring and MHSS were confirmed. Two submarine springs, Creature Hole and Sparky Lee were also confirmed. Spring #3 is the deepest spring and Dormant Spring is the shallowest.
There appears to be a rough spatial correlation between vents located on land and the vents on the seafloor, in which all known vents are either to the west or north of Lake Okeechobee. Vent distribution in the MHSS study area appears to correlate with the structural pattern of the local seafloor. Backscatter data and SCUBA observations show that fine to medium grain siliciclastic sediment bands overlie limestone hardbottom in a NE-SW orientation. Although vent geomorphologies are generally distinctive, vent activities generally correlate with the steepness of vent depressions.Most active vents had slopes of 6 degrees or greater, with the exception of Rusty Spring and Near Rusty Spring whose slopes ranged from 2.5 degrees and 6 degrees; whereas all the inactive vents had slopes of 5 degrees or less. Most active vents have "V"-shaped profiles versus the "U"-shaped profiles of most of the inactive vents. The inactive springs have shallower maximum depths and shallower ambient seafloor depths than the active vents.
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Cavallaro, Danilo Salvatore. "Indagini geologiche integrate terra-mare del bordo orientale emerso e sommerso del M. Etna e relazioni con l'evoluzione geodinamica dell'area." Thesis, Universita' degli Studi di Catania, 2011. http://hdl.handle.net/10761/111.
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L'Etna e' interessato da un fenomeno di scivolamento geostatico verso est di alcuni cm/a che coinvolge l'intero fianco orientale e la cui origine e' da sempre molto dibattuta. Nuove indagini geofisiche (Multibeam, Side Scan Sonar e profili Sparker e Sub Bottom Chirp) recentemente acquisite hanno permesso una dettagliata visualizzazione dell'offshore etneo. Il margine continentale ionico etneo appare dislocato da un ampio bulge che risulta affetto da un sistema di faglie semicircolare con un assetto a gradinata interpretato come un'evidenza d'instabilita' gravitativa a larga scala. I lineamenti appartenenti a questo sistema semicircolare si estendono anche lungo il settore costiero subaereo dove risultano confinati all'interno di un settore dove recenti misure SAR mostrano i maggiori valori di deformazione. All'interno di questo bulge sono stati individuati alcuni domini fisiografici che risultano coinvolti dall'instabilita'. Sia l'instabilita' dell'offshore che lo scivolamento subaereo appaiono confinante da due importanti discontinuita' di importanza regionale interpretate come linee di debolezza che accomodano il movimento verso est dell'intero fianco orientale su cui si trova un notevole spessore di vulcaniti. I nuovi dati hanno permesso di reinterpretare l'assetto tettonico della costa orientale etnea e di proporre un modello evolutivo del margine continentale etneo centrato su un'instabilita' retrograda che si sviluppa nell'offshore per poi propagarsi al settore costiero. Questo modello potrebbe fornire importanti elementi utili a capire il perche' un vulcano basaltico molto attivo si trovi sul fronte di una catena.Etna volcano is affected by a downward sliding of its eastern flank as fast as a few cm/year, whose nature is highly debated. New marine geophysical data recently collected allows a detailed image of the morphostructural setting of the continental margin facing the volcano. There a large bulge offsets the margin that is deeply affected by widespread semicircular steps, interpreted as evidences of large-scale gravitational instability. Such features permeate the whole margin affecting important physiographic domains and extend inshore matching the volcano sector where the larger ground deformations are measured. Both submarine instability and subaerial flank sliding are bounded by two regional tectonic lineaments interpreted as weakness lines crossing the coastline to accommodate the basinward movement of this large sector of the continental margin topped by Etna volcanic pile. The new data allows to re-interpret the tectonic setting of the coastal belt and to propose a novel structural model, pointing out an active role of the continental margin instability to drive the seaward sliding of volcano eastern flank. This model may suggest why a very active basaltic volcano unusually develops in front of an active thrust belt.
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Булашенко, Андрій Васильович, Андрей Васильевич Булашенко, and Andrii Vasylovych Bulashenko. "Використання лінз Ротмана для живлення антенних решіток." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/21034.
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Nascimento, Guilherme Antonio Gomes do. "Verificação da aplicabilidade de dados obtidos por sistema LASER batimétrico aerotransportado à cartografia náutica /." Presidente Prudente, 2019. http://hdl.handle.net/11449/181407.
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Orientador: Mauricio GaloResumo: Um Levantamento Hidrográfico (LH) tem como principal meta a obtenção de dados para a edição e atualização de documentos náuticos, estes, voltados à segurança das atividades de navegação. Objetivando padronizar parâmetros de incerteza das cartas náuticas, a Organização Hidrográfica Internacional (OHI) define níveis mínimos de confiança para diferentes ordens. A sugestão dessas especificações foi internalizada pela Marinha do Brasil, responsável pela produção das cartas náuticas brasileiras, na NORMAM-25. Um desses parâmetros é a Incerteza Vertical Total máxima permitida, um indicador de qualidade da medição da profundidade. A informação de profundidade influencia no calado máximo permitido a uma embarcação para transitar em uma região com segurança, o que pode impactar inclusive nas limitações de transações comerciais em terminais portuários, uma vez que as profundidades estimadas com acurácia potencializam os parâmetros de operação dos portos. Por se tratar de um ambiente dinâmico, seja por ação da própria natureza ou devido a atividades antrópicas, a atualização de uma carta náutica deve ser uma preocupação constante. Como complemento à tradicional técnica de levantamento por meio de um ecobatímetro acoplado a embarcações, há a opção de se realizar um LH com o emprego da tecnologia LiDAR (Light Detection And Ranging) a partir de aeronaves, por meio de um aerolevantamento batimétrico por LiDAR (ALB – Airborne LASER Bathymetry), que operam com pulsos LASER na região verde do e... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: A Hydrographic Survey (HS) has as main goal to obtain data for editing and updating nautical documents, these, focused on the safety of navigation. In order to establish a standard of uncertainty parameters for nautical charts, the International Hydrographic Organization (IHO) defines minimum levels of confidence for different orders. The suggestion of these specifications was acknowledged by the Brazilian Navy, institution responsible to produce Brazilian nautical charts, as described in NORMAM-25. One such parameter is the maximum allowed Total Vertical Uncertainty, a quality indicator of the depth measurement. Depth information influences the maximum operational draft for a vessel to safely travel in a region, causing impact on port operations and limiting the commercial transactions. Accurately estimated depths enhance the operational parameters of the ports. Due to the aim of representing a dynamic environment, whether as consequence of the action of nature itself or because of anthropic activities, updating a nautical chart must be a constant concern. As a complement to the traditional survey technique conducted with a boat-coupled echosounder, there is the option of performing a HS using LiDAR (Light Detection And Ranging) technology from aircraft, through LiDAR aerial bathymetry (ALB - Airborne LASER Bathymetry), which operate with LASER pulses in the green region of the electromagnetic spectrum. Considering these points, this work analyzed the differences between the... (Complete abstract click electronic access below)
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