The aim of this thesis is to test the accuracy of the heights measured by GNSS RTK with service providers CZEPOS and Trimble VRS Now. The thesis deals with precise of height measurement with the influence of surrounded obstacles, such as multipath, fading with the tall buildings, presence of high-voltage lines, limited shadow horizons at the edge of the forest, and measurement under the ideal conditions. The work also deals with the comparison of the period initialization of these monitored conditions. In the locations mentioned a network of test points was built. For measuring GNSS Leica System 1200 apparatus was used. It was measured always five times in five-second epochs and three times twenty-second epochs for each provider in five locations and thirty points during the mornings and afternoons. For independent height comparison the technical levelling was used. The outcome can be applied in practical use.

This Thesis deals with the evaluation of height accuracy of GNSS point positioning. Many experimental measurements aimed on GNSS and heights issues was realised within this work. The ellipsoidal heights were measured together with the orthometric heights and then the local Quasigeoid model was created. The network of height points was built to realisation of proposed measurements on the territory of the city Brno. The model of Quasigeoid from experimental measurement was compared with any other models of Quasigeoid and with local astronomical model. The partial aim of this Thesis is the proposal of methodology of height determination by GNSS technology and levelling measurement together. We can determine or verify the orthometric heights by using GNSS measurement and this methodology.

The present-day kinematics and deformation of the Arabian plate and the southern Red Sea region involves interaction of tectonic and non-tectonic processes including plate subduction, continental collision, seafloor spreading, intraplate magmatism, continental transform faulting, microplate rotation, hydrological loading cycles, and anthropogenic activity. Therefore, good constraints on the rates and directions of relative plate motion, plate boundary locations, and rheological properties in the area are essential to assess seismic and volcanic hazards in the region. In this thesis, I combine Global Navigation Satellite System (GNSS) measurements from over 200 stations with kinematic block modeling to provide updated estimates of the present-day motions of the Arabian plate and the southern Red Sea region. Using the non-rigid residual motions and changes in GNSS station baselines, I provide quantitative constraints on the internal deformation for the Arabian plate at different spatial scales. In addition, I use the GNSS station response to seasonal water exchange in the Red Sea to make inferences of the lithospheric elastic properties beneath Arabia. The GNSS-derived velocity field indicates coherent motion of both the Danakil block in the southern Red Sea and the Arabian plate at present. Current motions in the southern Red Sea region, however, are inconsistent with previous interpretations and require an additional plate boundary in the area. My updated fault slip rates improved earlier estimates limited by the number and spatial distribution of GNSS stations, particularly for the Arabian-Indian plate pair, for which slower right-lateral strike-slip motions are predicted. Non-rigid residual velocities within the Arabian plate interior indicate that large-scale internal deformations are compensated internally. However, at a smaller scale, I identify several localities accommodating significant strain, mostly related to anthropogenic activity. Ground response to surface mass loading associated with water transport in the Red Sea suggests that the Earth’s elastic structure beneath the Arabian plate is 20% to 30% less stiff than global averaged (i.e., AK135-F planetary model). Still, the lithosphere beneath both the Danakil block and the Arabian plate remains strong despite being affected by significant faulting and magmatism associated with the Nubian-Arabian-Eurasian plate interaction.

The thesis deals with precision analysis, process optimization and repeatibility of GNSS-RTK measurements for surveying aplication. Measuring procedure, that enables determination of a spatial position with a permissible deviation less than 10mm, was tested based on previous published findings. The test procedure was tested on two sets of test measurements obtained during 27 h and 26 h observations in connection with CZEPOS. The results were later analyzed. The first set of measurements was measured by the RTK3-GG method (9 m and 60 km vectors) and computed by a network solution VRS3-MAX-GG. Both were in ideal conditions – ideal, not obstructed observational horizon and good availability of differential corrections. The second set was measured by RTK3-GG method (22 km and 62 km vectors) and computed by network solution VRS3-MAX-GG. Both were in adverse conditions - obstructed observational horizon and adverse availability of differential corrections. Precision analysis and design of appropriate filtering method and optimal measurement procedure were done based on the results obtained from the test measurements. Optimal measurement procedure was then tested by measurements in a three point network.

The content of this work is an overview of precision approach used by GNSS and avionics for operation in low visibility conditions. This thesis describes existing requirements and proposals for new standards that are important to define GBAS performance. The objective of this work is to compare the alternative systems to guide aircraft during precision approach CAT II/III. GBAS operational implementation is additionally devised in this thesis.

[ES] En el marco de esta tesis se van a estudiar, principalmente, los efectos del movimiento de alta dinámica en receptores de Sistemas Globales de Navegación por Satélite (GNSS). El término alta dinámica es un término utilizado para referirse al movimiento de los vehículos en los que van embarcados receptores GNSS, los cuales se mueven lo suficientemente rápido como para causar un gran desplazamiento en frecuencia de la portadora debido al efecto Doppler. Se identificarán los problemas inherentes a este tipo de entornos y se estudiarán y propondrán soluciones. Para poder efectuar el estudio de estos fenómenos, se diseñará un demostrador tecnológico (conjunto de hardware y software para prueba y prototipado de tecnologías) en el que desarrollar el estudio de los casos de interés. Con el fin de trabajar en un entorno repetible, se utilizará un generador de señal GNSS. La señal generada se traslada a un receptor de radiofrecuencia definido por software, Software Defined Radio (SDR). Este tipo de receptor únicamente se encarga de digitalizar la señal de entrada y de llevar las muestras digitales a un ordenador, de modo que todo el procesado de señal se implementa en dicho ordenador. Este esquema de trabajo es ideal habida cuenta de su simplicidad y flexibilidad. Dicha flexibilidad conlleva la posibilidad de sintonizar el demostrador para poder estudiar una amplia gama de arquitecturas de receptor GNSS. Una vez se haya ensamblado el demostrador, se comprobará su correcto funcionamiento en escenarios conocidos usando los algoritmos más utilizados a día de hoy en receptores GNSS. Asegurado el correcto funcionamiento, se comparará el rendimiento de algoritmos de referencia con los algoritmos a estudiar y se extraerán conclusiones. / [CAT] En aquest treball s'estudiaran, principalment, els efectes del moviment d'alta dinámica en receptors de Navegació per Satèl.lit GNSS (Global Navigation Satellite System). La denominació alta dinámica, s'utilitza per a descriure el moviment dels vehicles dins dels quals hi han receptors GNSS. El moviment d'aquests vehicles és suficientment ràpid com per a causar un gran desplaçament en freqüència de la freqüència portadora. Aquest desplaçament és consqüència de l'efecte Doppler. S'identificaran els problemes inherents d'aquest tipus de entorns GNSS i es propsararàn solucions. Per a estudiar l'efecte de l'alta dinàmica, es dissenyarà un demostrador tecnològic (conjunt de maquinari i software per a proves i prototipat de tecnologies) en que es pot desenvolupar l'estudi dels casos d'interès. Amb l'objectiu d'aconseguir treballar en un entorn repetible s'utilitzarà un generador de senyal GNSS. El senyal es processarà mitjançant un receptor SDR (Software Defined Radio). Aquest tipus de receptor s'encarrega del processat que fa un receptor GNSS en un PC. Aquesta filosofia de treball és idónia per la seua flexibilitat i simplicitat. Quan s'haja ensamblat el demostrador, és comprovarà el seu correct funcionament en escenaris de prova utilitzant els algoritmes implementats en receptors GNSS comercials. En aquest moment, el demostrador estarà preparat per a estudiar el casos d'alta dinàmica, que és l'objectiu fonamental d'aquest treball. / [EN] The study of the effects of the high dynamics on Global Navigation Satellite System (GNSS) receivers constitute the main matter of study in this work. The term high dynamics refers to the movement of vehicles that carry GNSS embedded receivers, which move fast enough to generate a large carrier frequency drift caused by the Doppler effect. The problems linked to these environments will be characterized and solutions to counteract possible signal impairments will be discussed. In order to correctly characterize these problems, a technological demonstrator (set of hardware components interacting with software tools enabling fast prototyping) will be designed and constructed. Using this technological demonstrator, different case studies will be developed. With the aim of achieving experimental repeatability, a GNSS signal generator will be used. The generated GNSS signal is fed to a Software Defined Radio (SDR) GNSS receiver. This receiver type is in charge of digitizing the analog RF signal and carrying the resulting samples to a computer in which signal processing tasks implementing the functions of GNSS receivers, take place. The main advantage linked to the usage of this work scheme is that by changing the software part, different receiver architectures can be implemented in a simple manner. Furthermore, by taking advantage of the flexible architecture it is possible to tune the detector in such a manner that it is possible to implement many different architecture types. Once the technological demonstrator is assembled, tests to assure its correct operation will be conducted by performing comparisons with the behaviour of well-known GNSS receivers in known scenarios. Later on, comparative tests using signals from high dynamics scenarios will take place. Insight and analysis of comparative performance will be given. / Alcaide Guillén, C. (2019). Design and development of a technological demonstrator for the study of high dynamics GNSS receivers [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/131697 / TESIS

Localization systems nowadays are extensively used by a growing number of mobile devices, such as smartphones and tablets integrated with various applications, and their use for traditional purposes such as navigation and geodesy have pushed the development of new techniques and improved algorithms. The combination of multiple techniques is the most common approach. Global Navigation Satellite Systems, such as GPS are well known and established localization systems that have great accuracy but are limited to locations where the strength of the signal is good. Therefore a new approach that could increase the sensitivity and even the accuracy by using GPS could benet a large group of users. This thesis originally proposes a new approach for these signals, based on Particle Filters that proved to work well in mitigating problems in an audio-based localization system. The results obtained show that this approach can increase the sensitivity of the system as a whole and positions estimations can be achieved under conditions that previous systems were not able to.

The Coast Mountains in British Columbia contain over 10,000 km2 of glacial ice. While these glaciers have lost significant mass since the Little Ice Age (LIA; around 300 years before present), the melting rate has significantly increased over the past decade, likely due to the effects of climate change. The purpose of this study was to develop an approach to quantifying the isostatic response to LIA glacier change and investigate how it can further our understanding of the Earth’s rheology through GIA modelling. The Coast Mountains in southwestern British Columbia were chosen due to their significant ice mass loss since the LIA, their location in a tectonically active region, which includes a volcanic arc, and the presence of information of vertical land motion. The GIA models in this study use a wide range of Earth rheological parameters that are then constrained through comparison to observations of vertical land motion in the region. The study used available Global Navigation Satellite System (GNSS) vertical velocity data as the observable from seven GNSS sites in southwestern BC, using a combination of Western Canada Deformation Array (WCDA) and British Columbia Active Control System (BCACS) GNSS stations. Raw data were analyzed using the GIPSY 6.4 software following the Precise Point Positioning processing strategy. Two ice load histories were developed based on gridded estimates of present-day ice thicknesses in the region in order to simulate the change in the surface loading as the glacial ice mass fluctuates over time. Ice Load A used a simple uniform thickness change profile over 3 time-steps based on extrapolated modern melt rates. Ice Load B is more complex and utilized a published profile of glacier change through time basing the magnitude of volume changes on the volume-area scaling relationship with a range of coefficient values. This allowed for a range of ice change magnitudes to be tested. The Earth models used were spherically symmetric Preliminary Reference Earth Models (PREM). Their viscosity structure is based on VM5a for the transition zone and lower mantle, but with variable lithospheric thickness and asthenospheric viscosity. The goodness of fit for the modeled velocities were compared to the observed velocities using a normalized RMS (NRMS) statistic. Ice Load A models had a best fitting lithospheric thickness of 50 km and an asthenospheric viscosity of 2×1019 Pa s. For all variations of Ice Load B, the best fitting model parameters had lithospheric thicknesses ranging from 45 km to 55 km and asthenospheric viscosities between 6×1018 Pa s and 3×1019 Pa s. Corrected GNSS vertical velocity observations were tested to check the effects of interseismic vertical signal and assumed residual GIA from the Cordilleran Ice Sheet. However, the corrections did not improve the NRMS fit. Overall, the asthenospheric viscosity results from this study overlap with all the ranges found in the previous studies while lithospheric thicknesses agree with some past studies. The results of this study generally align with previous work and the current understanding of the Coast Mountains region and can inform a future round of sea-level projections for the region as ice mass loss continues in the Coast Mountains. This study serves to further refine constraints on Earth rheology and can be used to guide future work on GIA in the region. / Graduate

By tomography of GNSS slant delay data the refractivity fields of the atmosphere can be reconstructed. The resolution of the tomography field is about 40 km in horizontal and several 100 m in vertical direction. In 2009 about 270 GNSS stations were available in Germany. The tomographically reconstructed humidity fields have to be validated with other observation methods which are able to detect the refractivity profiles of the atmosphere. The data used to compare is from radiosonde soundings, by which the refractivity can be calculated. The first results of the comparison of GNSS data with radiosonde data from two radiosonde stations in Germany are shown.

Begreppet drönare för de flesta utomstående förknippas oftast med hobbyverksamhet i form av foto- och videoskapande. Det senaste åren har allt fler byggföretag valt att satsa på arbetsmetoder där drönare tillåts ersätta befintlig utrustning. Detta examensarbete utfördes för att kartlägga potentialen hos drönarserien Phantom 4, samt de rådande för- och nackdelar med tekniken. Aktuellt är bland annat att studera hur planering-, utförande och bearbetningsskedet påverkas då drönare tillåts användas inom projekt. Syftet med denna studie är att planlägga vid vilka projekt dagens drönarteknik (Phantom 4) kan tillämpas samt de möjligheter som så kallad RTK-teknik kan ha för vidare betydelse för aktörer som vill uppgradera sin drönaranvändning och utrustning. Under arbetets gång har information granskats ifrån tidigare arbeten, litteraturstudier samt intervjuer med nyckelpersoner på Pontarius AB. Dessa personer arbetar dagligen med frågor och projekt som berör ämnesområdet, vilket varit användbart för att styrka det slutsatser som rapporten slutligen kunnat dra. Studien bekräftar att Phantom 4 serien har möjligheten att underlätta planeringen, utförandet och bearbetningen. Genom att göra arbetsmiljön säkrare uti fält, men också genom att minska mängden data som behöver korrigeras manuellt i efterhand. Samtidigt föreligger i dagsläget vissa begränsningar för drönartekniken. Däribland återfinns det faktum att drönaren inte når den precision i alla lägen som en traditionell inmätning gör och att den är begränsad av yttre faktorer, såsom vindkänslighet, väderberoende samt begränsad batteritid. Sammanfattningsvis kan studien konstatera att kunder till Pontarius AB fäller en avgörande roll inför vilken riktning som drönartekniken tillåts utvecklas inom företaget. Efterfrågan på den information som Phantom 4 kan tillhandahålla saknas i mångt och mycket ifrån kundens sida. Detta gör att tekniken inte kan nå sin fulla potential då den inte naturligt tillåts inkluderas i alla avseenden. Trots detta anser vi att en investering i en Phantom 4 RTK bör övervägas å Pontarius AB´s vägnar då denna drönartyp kan bidra med högre inmätningsnoggrannhet och enklare bearbetning av insamlat material.