Usando o modelo de ajustamento apresentado por Schaffrin (2001), este trabalho apresenta uma metodologia para ajustamento de redes geodésicas GPS de densificação e extensão, a qual substitui com vantagem o tratamento clássico que utiliza um ajustamento livre seguido por uma \"transformação de Helmert\". A característica deste método é introduzir um procedimento estatisticamente ótimo, baseado no princípio dos mínimos quadrados, que permita ajustar a nova rede, vinculando-a a pontos fiduciais, e conectando-a a pontos de ligação com redes vizinhas de mesmo nível, considerados \"hierarquicamente superiores\" no processo. A técnica da \"propriedade reprodutora\" permite que esses pontos sejam ponderados em função das variâncias decorrentes de suas determinações, mas tenham suas coordenadas preservadas. Para a implementação dessa metodologia, foi desenvolvido um programa, em linguagem FORTRAN, que realiza o ajustamento vetorial da rede, utilizando o modelo paramétrico do método dos mínimos quadrados. O procedimento adotado consiste em fazer com que as variâncias dos pontos de injunção sejam introduzidas na nova rede, e que as coordenadas desses pontos, modificadas pelo ajustamento, sejam recuperadas. O programa apresenta também uma seqüência de testes que possibilitam a detecção, investigação e adaptação de possíveis erros encontrados. / By using the adjustment model presented by Schaffrin (2001), this work presents a methodology for the adjustment of GPS geodetic networks of densification and extension, which substitutes with advantage the classic treatment that uses a free net adjustment followed by a \"Helmert transformation\". The feature of this method is to introduce a statistically optimal procedure, based on least squares principle, that allows adjust the new network, linking it to fiducial points and connecting it to tiepoints with same level neighbor networks, all of them considered \"hierarchically superior\" in the process. The \"reproducing property\" technique allows that these points were weighed up as a function of the variances obtained in the preliminary determination, but they have their coordinates preserved. For this methodology implementation, a software in FORTRAN language was developed for the network vectorial adjustment, by using the linear parametric model of least-squares method. The adopted procedure allows the constraint point variances to propagate in the new network, but afterwards the coordinates of these points, changed in the adjustment, are retrieved. The software presents a sequence of tests to detect, to investigate and to analyze possible encountered errors, too.

Em levantamentos geodésicos planialtimétrico se faz necessário conhecer a qualidade das coordenadas estimadas de acordo com o tipo de aplicação a que se destinam. Este trabalho mostra de modo didático o estudo das teorias de análise de qualidade de rede GPS, baseando-se nas teorias de confiabilidade de rede propostos por Baarda, em 1968. As hipóteses estatísticas são fundamentais para elaboração dos testes para detecção de erros grosseiros (outliers), que constitui a base para a análise da confiabilidade de rede. Neste trabalho são propostas três estratégias, desenvolvidas em MathCAD, para a análise da qualidade do ajustamento. Os resultados obtidos foram comparados com os dos programas comerciais, Ski-Pro e Ashtech Solution, e também validados por medidas de campo feitas com estação total. As três estratégias propostas, para a rede em estudo implantada no Campus II da USP, apresentaram bons resultados / Geodetic planimetric survey requires the knowledge of the coordinates quality, estimated according to the final application. This work shows a didactic way on the study on theoretical analyses on quality of GPS networks, based on reliability network proposed by Baarda in 1968. Statistical hypotheses are fundamental to development of outliers’ detection tests, which consists the base for network reliability. In this work, three strategies are proposed, developed in MathCAD, to analyze adjustment quality. The results were compared with the results of two commercial programs, Ski-Pro and Ashtech Solution, and also field validation measurements with total station. The three proposed strategy, applied on a pilot network located at the Campus II of USP, gave good results

The determination of the figure of the Earth and its gravity field has long relied on methodologies that approximate the Earth by a sphere, but this level of accuracy is no longer adequate for many applications, due to the advent of new and advanced measurement techniques. New, practical and highly accurate methodologies for gravity field modelling that describe the Earth as an oblate ellipsoid of revolution are therefore required. The foundation for these methodologies is formed by solutions to ellipsoidal geodetic boundary-value problems. In this thesis, new solutions to the ellipsoidal Dirichlet, Neumann and second-order boundary-value problems, as well as the fixed- and free-geodetic boundary-value problems, are derived. These solutions do not rely on any spherical approximation, but are nevertheless completely based on a simple spherical harmonic expansion of the function that is to be determined. They rely on new relations among spherical harmonic base functions. In the new solutions, solid spherical harmonic coefficients of the desired function are expressed as a weighted summation over surface spherical harmonic coefficients of the data on the ellipsoidal boundary, or alternatively as a weighted summation over coefficients that are computed under the approximation that the boundary is a sphere. / Specific applications of the new solutions are the computation of geopotential coefficients from terrestrial gravimetric data and local or regional gravimetric geoid determination. Numerical closed-loop simulations have shown that the accuracy of geopotential coefficients obtained with the new methods is significantly higher than the accuracy of existing methods that use the spherical harmonic framework. The ellipsoidal corrections to a Stokesian geoid determination computed from the new solutions show strong agreement with existing solutions. In addition, the importance of the choice of the reference sphere radius in Stokes's formula and its effect on the magnitude and spectral sensitivity of the ellipsoidal corrections are pointed out.

The laser geodetic satellites Lageos and Starlette exhibit residual orbital motion with an unexplained seasonal component. In addition, recognized polar motion excitation sources do not account for a large portion of observed polar motion. It is hypothesized that air and ocean mass redistribution is the primary source of seasonal perturbations in satellite motion, and that wind-driven ocean mass redistribution is a major source for polar motion excitation. Average monthly variations in zonal spherical harmonic geopotential coefficients are estimated from NMC air pressure for 1958 through 1973, and from variations in continental water storage predicted by a global hydrologic model. These coefficients are used to predict average monthly perturbations in the longitude of the ascending node ([Omega]) for Lageos and Starlette, and in the eccentricity vector ([Psi]) for Starlette. WMO monthly air pressures and twice-daily Navy sea level pressures are used to predict time series of [Omega] and [Psi] perturbations for Lageos during 1976 through 1985, and for Starlette during 1980 through 1983. In addition, the Hellerman and Rosenstein wind stress field for world oceans and the Gill-Niiler bottom pressure equation are used to estimate annual and semi-annual ocean mass redistribution, and to predict polar motion excitation vectors and Lageos [Omega] perturbations. Comparison of predicted [Omega] and [Psi] perturbations with observed Lageos and Starlette behavior indicate that air pressure may be responsible for much of the unmodeled seasonal variation in the Earth's geopotential. In contrast, the water storage contribution is very small. Year-to-year variability in the observed Lageos and Starlette [Omega] times series is well matched by predicted perturbations. Even after the removal of annual and semi-annual components, significant coherence remains between predicted and observed [Omega] time series for both Lageos and Starlette at periods of less than one year. Comparison of predicted polar motion with ILS observations suggest that the effect of ocean mass redistribution is significant, and second only to air pressure in magnitude. Lageos [Omega] perturbations predicted from ocean mass redistribution indicate that non-isostatic sea level fluctuations should be readily observable by satellite laser ranging. / text

Η εφαρμογή των γεωδαιτικών μεθόδων στη χάραξη και παρακολούθηση των υπογείων έργων ακολουθεί σε γενικές γραμμές μια συγκεκριμένη πρακτική η οποία όμως (1) δεν έχει τεκμηριωθεί ως προς την ακρίβεια και τα όρια εφαρμογής της, και (2) τα στοιχεία που συλλέγονται στα διάφορα έργα στη συντριπτική τους πλειοψηφία δεν αξιολογούνται ή αξιοποιούνται. Η παρούσα Διατριβή στοχεύει να συνεισφέρει στο διπλό αυτό στόχο και γι’ αυτό περιλαμβάνει δύο βασικές ενότητες: Η πρώτη ενότητα στοχεύει στην τεκμηρίωση της ακρίβεια της γεωδαιτικής μεθόδου με βάση αναλυτική και πειραματική προσέγγιση και διερευνάται η ποιότητα και η αξιοπιστία διαθέσιμων παρατηρήσεων από αριθμό υπογείων έργων. Ειδικότερα, υπολογίστηκε η ακρίβεια χάραξης σηράγγων, ανάλογη του κύβου του πλήθους στάσεων σκόπευσης. Στη συνέχεια εκτιμήθηκαν οι αναλυτικές ακρίβειες στον υπολογισμό των οριζοντίων και κατακορύφων μετακινήσεων και συγκλίσεων κατά την παρακολούθηση σηράγγων και πραγματοποιήθηκαν πειραματικές μετρήσεις για την ακρίβεια των γεωδαιτικών οργάνων και μεθόδων που εφαρμόζονται. Με βάση τα αποτελέσματα η γεωδαιτική μέθοδος κρίνεται επαρκής και ακριβής για τη χάραξη και παρακολούθηση των συνήθων σηράγγων. Η δεύτερη ενότητα, βασισμένη σε παρατηρήσεις από διάφορες σήραγγες, στοχεύει στον έλεγχο της κινηματικής σημείων ή διατομών ελέγχου σηράγγων, τον έλεγχο των γεωμετρικών χαρακτηριστικών συγκλίσεων αλλά και της τυπολογίας της χρονικής εξέλιξης των μετακινήσεων. Αναλύθηκαν περιπτώσεις χωροχρονικής εξέλιξης μετακινήσεων που αποκλίνουν από την τυπική μορφή, με βασικό χαρακτηριστικό την εμφάνιση απότομων, ανεξήγητων μετακινήσεων. Ειδικότερα, η ανάλυση των διαθέσιμων στοιχείων από τις σήραγγες Τυμφρηστού, Καλλιδρόμου κ.α. οδήγησε στο συμπέρασμα ότι η υπερβολική αύξηση των μετακινήσεων τοπικά σε μια περιοχή προκαλεί κάτω από ορισμένες συνθήκες αλυσιδωτά νέες μετακινήσεις σε γειτονικές, προσωρινά σταθεροποιημένες περιοχές του έργου. / Geodetic techniques are widely used for the guidance and monitoring of underground structures, but (1) their accuracy and efficiency are not tested and (2) deformation data, collected during tunnel excavation, are not further evaluated. A contribution towards the solution of both these problems is the aim of this dissertation, which consists of two parts. In the first part the applicability and accuracy of the geodetic techniques were assessed using analytical and experimental techniques. Three main conclusions were obtained. First, that the errors of coordinates along a tunnel are proportional to the cube of the number of stations. Second, it was found that non-prismatic reflectors have a non-linear response and contributes to significant errors (>1-2mm) in convergence measurements and third, that the noise of actual monitoring measurements from several tunnels is at maximum ±4mm. In the second part of this dissertation deformation data from a number of tunnels were analyzed. Analytical methodologies were introduced for the estimation of the geometrical pattern of tunnel section distortion and mathematical, function approximation techniques are followed to model the typical pattern of tunnel deformation. Studies of monitoring data from tunnels that faced instabilities and high deformation (as Tymfristos tunnel, Kallidromo tunnel etc.) revealed that high tunnel closure locally, may induce a new phase of deformation to other nearby, previously stabilized, sections.

Baigiamajame magistro darbe „Lietuvos geodezinio tinklo horizontaliųjų deformacijų apibendrintųjų charakteristikų tyrimas“ analizuojant geodezinių tinklų elementų pokyčius, nustatytus pagal pakartotinai atliktus geodezinius matavimus, tirtos Lietuvos teritorijos bei jos vakarinio ir rytinio blokų horizontaliosios deformacijos. Baigiamojo magistro darbo tikslas – atlikti Lietuvos geodezinio tinklo horizontaliųjų deformacijų apibendrintųjų charakteristikų tyrimą. Deformacijos, parenkant laisvo taškų poslinkio tolygiai besideformuojančioje dvimatėje erdvėje modelis, apskaičiuotos pagal trianguliacijos bei GPS tinklo kartotinius matavimus. Trianguliacijos matavimai atlikti 1926–1940 metais, GPS matavimai atlikti 1992–1996 metais bei 2007 metais. Horizontaliųjų deformacijų apskaičiuotų Lietuvos teritorijos bei rytinio ir vakarinio blokų tyrimui naudota tenzorinės analizės metodika. Tenzorinės analizės metodu apskaičiuoti Lietuvos teritorijos bei jos vakarinio ir rytinio blokų parametrai. Įvertintos horizontaliųjų deformacijų apibendrintos charakteristikos: didţiausias ir maţiausias santykinis pailgėjimas bei jų kryptys, santykinė dilatacija, antrojo rango deformacijų tenzoriaus elementai bei didţiausio santykinio pailgėjimo kryptys. Darbą sudaro 8 dalys: įvadas, penki skyriai, išvados, literatūros sąrašas. Darbo apimtis – 82 p. teksto be priedų, 36 iliustr., 23 lent., 26 bibliografiniai šaltiniai. Atskirai pridedami darbo priedai. / In the Master thesis called „Investigation of the Generalized Characteristics of the Horizontal Deformations of the Geodetic Network of Lithuania„ analising the changes of the elements of the geodetic networks determinated according to repeatedly performed geodetic measurements were investigated the territories of Lithuania and the horizontal deformations of its west and east blocks. The purpose of the Master thesis is to perform the investigation of the generalized characteristics of the horizontal deformations of the geodetic network of Lithuania. The deformations were calculated according to the repeated measurements of the triangulation and the GPS network by selecting the model of the free displacement of the points in an evenly formed two-dimensional space. The triangulation measurements were performed 1926-1940, the GPS measurements were performed 1992-1996 and in 2007. For the investigation of the horizontal deformations calculated in the territory of Lithuania and in the west and east blocks was used the tensor analysis method. The parameters of the territory of Lithuania and its west and east blocks were calculated using the tensoric analysis method. Also were measured the generalized characterisitcs of the horizontal deformations: the maximum and the minimum relative elongation and their directions, the relative dilatation, the second rank deformations of the elements of the tensor and the directions of the maximum relative elongation. The thesis is composed of 8... [to full text]

Thesis (M.A.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. "The National Oceanic and Atmospheric Administration's Historic Maps & Chart Project ... supplied the majority of the digital images used"--P. vi. Col. ill. on folded leaves. Includes bibliographical references (leaves 186-199). Also available online via the NOAA website as PDF file, viewed 11/28/08: <http://docs.lib.noaa.gov/noaa_documents/NOAA_related_docs/McConnel_USCGS_Charts_Thesis.pdf >

Thesis (M.A.)--University of Oregon, 2007. / Title from title screen (viewed on Oct. 15, 2007). "June 2007." Includes bibliographical references (p. 186-199).

Dissertation was worked on the theme " Project and surveying of the network for planimetry and hight points in the area of the river Jenín using several methods". Target of this dissertation was building of point field, their planimetry and altitude destination like basis for another telemetry in range. On the basis of geodetic and map data was effected reconnaissance of the area, estimation of current point field, their completion to required density and locating new points by geodetic and GPS methods. It was built net of 16 points of the detailed planimetry point field and eight of them was subjekt of my dissertation. For planimetry and altitude survey by GPS method was used Trimble 4600LS device. By geodetic method points was located by electronic total station Leica TCR 407 power. Altitude of the three points was determined by the technical levelling using levelling machine Topcon AT {--} 22A and the other hights of points was calculated trigonometrically. Part of dissertation was processing of surveyed data, execution of graphic enclosure and comparing both methods.

O objetivo deste trabalho é desenvolver e propor um novo método para o planejamento de redes geodésicas. O planejamento (ou pré-análise) de uma rede geodésica consiste em planejar (ou otimizar) a rede, de modo que a mesma atenda a critérios de qualidade pré-estabelecidos de acordo com os objetivos do projeto, como precisão, confiabilidade e custos. No método aqui proposto, os critérios a serem considerados na etapa de planejamento são os níveis de confiabilidade e homogeneidade mínimos aceitáveis para as observações; a acurácia posicional dos vértices, considerando tanto os efeitos de precisão quanto os (possíveis) efeitos de tendência, segundo ainda um determinado nível de confiança; o número de outliers não detectados máximo admissível; e o poder do teste mínimo do procedimento Data Snooping (DS) no cenário n-dimensional, isto é, considerando todas as observações (testadas individualmente). De acordo com as classificações encontradas na literatura, o método aqui proposto consiste em um projeto combinado, solucionado por meio do método da tentativa e erro, além de apresentar alguns aspectos inéditos em seus critérios de planejamento. Para demonstrar a sua aplicação prática, um exemplo numérico de planejamento de uma rede GNSS (Global Navigation Satellite System – Sistema Global de Navegação por Satélite) é apresentado e descrito. Os resultados obtidos após o processamento dos dados da rede GNSS foram concordantes com os valores estimados na sua etapa de planejamento, ou seja, o método aqui proposto apresentou desempenho satisfatório na prática. Além disso, também foram investigados como os critérios pré-estabelecidos, a geometria/configuração da rede geodésica e a precisão/correlação inicial das observações podem influenciar nos resultados obtidos na etapa de planejamento, seguindo o método aqui proposto. Com a realização destes experimentos, dentre outras conclusões, verificou-se que todo os critérios de planejamento do método aqui proposto estão intrinsecamente interligados, pois, por exemplo, uma baixa redundância conduz a um valor relativamente mais alto para a componente de precisão, e consequentemente, um valor relativamente mais baixo para a componente de tendência (mantendo a acurácia final constante), o que também conduz a um poder do teste mínimo nos cenários unidimensional e n-dimensional significativamente mais baixos. / The aim of this work is to develop and propose a new method for the design of geodetic networks. Design (planning or pre-analysis) of a geodetic network consists of planning (or optimizing) the network so that it follows the pre-established quality criteria according to the project objectives, such as accuracy, reliability and costs. In the method proposed here, the criteria to be considered in the planning stage are the minimum acceptable levels of reliability and homogeneity of the observations; the positional accuracy of the points considering both the effects of precision and the (possible) effects of bias (according to a given confidence level); the maximum allowable number of undetected outliers; and the minimum power of the test of the Data Snooping procedure (DS) in the n-dimensional scenario, i.e., considering all observations (individually tested). According to the classifications found in the literature, the method proposed here consists of a combined project, solved by means of trial and error approach, and presents some new aspects in their planning criteria. To demonstrate its practical application, a numerical example of a GNSS (Global Navigation Satellite System) network design is presented and described. The results obtained after processing the data of the GNSS network were found in agreement with the estimated values in the design stage, i.e., the method proposed here showed satisfactory performance in practice. Moreover, were also investigated as the pre-established criteria, the geometry/configuration of the geodetic network, and the initial values for precision/correlation of the observations may influence the results obtained in the planning stage, following the method proposed here. In these experiments, among other findings, it was found that all the design criteria of the method proposed here are intrinsically related, e.g., a low redundancy leads to a relatively higher value for the precision component, and consequently to a relatively lower value for the bias component (keeping constant the final accuracy), which also leads to a minimum power of the test significantly lower in the one-dimensional and the n-dimensional scenarios.