Geodetic Deformation Analysis

The use of GPS for the estimation of orthometric heights in a given region, with the help of existing levelling data requires the determination of a local geoid and the bias between the local levelling and the one implicitly defined when the geoid is calculated which is generally based on the gravity anomalies data. The heights of new data can

SUMMARY This paper presents some first results of a project aimed to access the feasibility of monitoring deformations of large concrete dams by terrestrial laser scanning. Case study of Studena Dam in Bulgaria is described. A large number of retro-reflecting targets have been positioned and measured by a total station in the local datum. Moreover, targets are measured also in captured scans. They are placed in the surroundings as ground control point. Two measurement campaigns are accomplished so far: the second one after earthquake in Pernik on 22.05.2012. Reported analyses are focused on two main problems: the first one is the accuracy and the stability of georeferencing, which is fundamental to make comparisons between different multi-temporal scans; the second one is the computation of deformation based on the acquired point-clouds. Moreover, some notes about a method to compute the accuracy of surface points which have been measured by terrestrial laser scanning are reported.

РЕЗЮМЕ
В статията са представени първите резултати по проект изследващ възможността за използване на наземно лазерно сканиране за мониторинг на деформации на големи бетонни язовирни стени. Разглежда се приложението на метода за язовир Студена. Контролни точки са стабилизирани извън деформационната област на обекта и са измерени с тотална станция в локална координатна система. Точките също така са сканирани за трансформиране на измерванията с лазерния скенер в локалната координатна система. Извършени са два цикъла измервания като вторият е след земетресението в гр. Перник на 22.05.2015 г. изложения анализ е фокусиран върху два основни проблема: първият е точността и стабилността на геореферирането, който е основен при сравнението на данни от различни епохи, а вторият е изчислението на деформациите при сравнението на облаци от точки.

Abstrak. Indonesia terletak di pertemuan empat lempeng besar dunia: Lempeng Eurasia, Lempeng Pasifik, Lempeng Filipina, dan Lempeng Indo-Australia. Oleh karenanya, banyak wilayah Indonesia memiliki potensi besar akan bencana gempa bumi. Jawa Barat merupakan salah satunya, karena terletak pada zona penunjaman antara Lempeng Indo-Australia dengan Lempeng Eurasia. Hal tersebut pula yang membuat Jawa Barat kaya akan struktur geologi, salah satunya adalah sesar. Setidaknya terdapat tiga buah sesar besar aktif di Jawa Barat, yaitu Sesar Cimandiri, Sesar Lembang, dan Sesar Baribis. Sesar Baribis merupakan sesar besar aktif yang terbentuk paling akhir setelah dua sesar besar aktif lain di Jawa Barat. Jalur Sesar Baribis membentang dari Subang hingga kaki bagian selatan Gunung Ciremai. Dikarenakan keaktifannya, Sesar Baribis memiliki potensi yang cukup besar akan terjadinya gempa bumi. Potensi gempa bumi tersebut menjadi semakin membahayakan karena Sesar Baribis melintasi daerah-daerah padat penduduk dan juga tak jauh dari bentangan Sesar Baribis, terdapat Waduk Jatigede. Berdasarkan alasan tersebut, diperlukan pemahaman yang mendalam dan pemantauan aktivitas pada Sesar Baribis. Salah satu metode yang dapat digunakan dalam pemantauan aktivitas Sesar Baribis tersebut adalah observasi dengan Global Positioning System (GPS). Dalam penelitian ini akan dilakukan pengamatan GPS di sekitar Sesar Baribis untuk kemudian diolah dengan menggunakan piranti lunak pengolah data GPS ilmiah Bernese 5.2 yang selanjutnya digunakan untuk menentukan nilai vektor pergeseran, mengkuantifikasi pola regangan, serta menentukan besar laju geser untuk keperluan analisis deformasi. Berdasarkan analisis deformasi tersebut, dapat diketahui bagaimana aktivitas sesar yang terjadi di Sesar Baribis.

This monograph defines the place, role, and importance of engineering surveying in the field of deformation monitoring, deformation surveys, and geotechnical monitoring. Тhe monograph represents the author’s experience in this field-the presentation of deformation ellipsoid in a topocentric (local level) coordinate system for deformation analysis, strain analysis, common processing of GPS and terrestrial measurements, determining the tilting of buildings and facilities, and preliminary and optimal design of deformation monitoring schemes.

The use of GPS for the estimation of orthometric heights in a given region, with the help of existing levelling data requires the determination of a local geoid and the bias between the local levelling and the one implicitly defined when the geoid is calculated which is generally based on the gravity anomalies data. The heights of new data can be collected swiftly without using the orthometric heights from levelling; it is what one calls commonly levelling by GPS. In this framework, the Least Squares Collocation method (LSC) has been used to evaluate the quality of the available GPS-Levelling data, to determine a gravimetric geoid in the North region of Algeria and to estimate the constant datum bias. The data used in the setting of this study are: The geopotential model EGM96, a total number of 2534 gravity anomalies, as well as 43 GPS points connected to the geodetic network levelling present on the whole North part of Algerian.

Landslide area occurs on steep-slope and forestry. Generally, investigations are pursuing on the difficult topographical area for monitoring a landslide. GNSS measurements and analysis are providing very accurate, large content, scope and reliable information to monitoring movements on ground surface. Most techniques are not possible produce safe results for stability of the slope in forestry area. GNSS measurement techniques are the most reliable technique to monitoring slopes. This paper is aimed to present landslide monitoring with Global Navigation Satellite System (GNSS) measurements and to compare performance of Precise Point Positioning(PPP) method and rapid-static GNSS solution. Study area is located on the Middle of Taurus mountain chains. Three epoch GNSS campaigns for monitoring were performed on the study site from 2011 to 2012. For the purpose of detecting surface movement, ground monitoring points conducted on reachable areas and clean sky view in complex and dense forestry topography. In this study, GNSS data were processed by post-processed PPP method and rapid static GNSS solution for the purpose of comparison. Abrupt heavy rainfalls in area resulted 4m displacement top-scarp of landslide area. The landslide toe moved forward averagely 1-2 m between campaigns. Processing results show that differences between PPP-derived and rapid-static-derived displacement are within dm level. As a conclusion, in case of limited GNSS receiver, post-processed static PPP method can be used as an efficient alternative to the rapid-static GNSS method to detect displacement caused by landslide.

The Province of Yogyakarta is an area with high level of seismic activity in Indonesia. One of the active faults in this provice is Opak Fault, which was regarded as responsible for Yogyakarta earthquake of May 27, 2006. It is necessary to establish geodetic network for monitoring around the fault, with more detailed geologic mapping.
The research was conducted with several stages since the literature review, discussions with colleagues in the Laboratories of Geodesy and Geodynamic, Faculty of Engineering, Universitas Gadjah Mada. The first research procedure includes planning for bench-mark (BM) installation, and Global Navigation Satellite System (GNSS) data acquisition, Linux Centos V. 6.5 as Operating System and
GAMIT/GLOBK V 10.5 as scientific software for data proccesing. Measurement of monitoring network in
this area was carried out on 18 November 2013. The second research percedure was Geological observation and mapping which were conducted for about three weeks in the August 2013.
The research has established 10 BMs for monitoring network point using 3D Cartesian coordinates system. Pasive stations were labelled OPK 3, OPK 4, OPK 6, OPK 7, OPK 8, TGD 2, and active stations were labelled GK1_,KPG1,SLM1and BTL1. Distance between network monitoring stations ranges from
6,045.67385 m for the shortest distance OPK 6 to GK1_ and 4,3603.16313 m for longest distance of OPK 6 to KPG1, with precision of base lines varies from 3.94 mm to 10.61 mm, standard deviation of on the X-as (x) , Y-as (y) and Z-axis as (z) are varies. Standard deviations of 3D Cartesian coordinates system for pasive and active stations have similar pattern where y lesser than x dan z. Geological
mapping and field observation on the suspected area for the seismogenic fault suggest that the Mangunan-Muntuk region was influenced by similar tectonic forces as in 2006 earthquake.

Although, there are various software that perform least squares adjustment of horizontal geodetic network so as to determine the precision and accuracy of the network. But the theories and equations that were used to develop the programs which the software are using are not quite understood by various user. This paper presents step by step procedures of horizontal geodetic network precision and accuracy determination using observation equation method of least squares technique. The detailed procedures are enumerated in sequential order for users understanding. The enumerated procedures are also demonstrated using a numeric example.

The research project SIMULTAN applies an advanced combination of geophysical, geodetic, and modelling techniques to gain a better understanding of the evolution and characteristics of sinkholes. Sinkholes are inherently related to surface deformation and, thus, of increasing societal relevance, especially in dense populated urban areas. One work package of SIMULTAN investigates an integrated approach to monitor sinkhole-related mass translations and surface deformations induced by salt dissolution. Datasets from identical and adjacent points are used for a consistent combination of geodetic and geophysical techniques. Monitoring networks are established in Hamburg and Bad Frankenhausen (Thuringia). Levelling surveys indicate subsidence rates of about 4–5Here, the concept of combining geodetic and gravimetric techniques to monitor and characterise geological processes on and below the…

Die Geographie des Klaudios Ptolemaios (um 100 bis 178 n.Chr.) beschreibt die damals bekannte Welt (Europa, Asien und Nordafrika) mit 6347 antiken Ortsnamen einschließlich ihrer geographischen Koordinaten. Davon sind ca. 3600 Ortsangaben mit heutigen Orten bzw. topographischen Merkmalen identifiziert. Sie dienen als Passpunkte bei der Transformation von unbekannten Ortsangaben in das heutige geographische Koordinatensystem (WGS84). Der Beitrag beschreibt die historischen Datenquellen, die damaligen Messmethoden sowie bisherige und neue Transformationsmethoden, wobei die speziellen Probleme der Geographie und mögliche Ursachen von Transformationsfehlern diskutiert werden.

The Geography of Claudius Ptolemy (around 100 to 178 AD) describes the world known at that time (Europe, Asia and North Africa) listing 6347 ancient place names including their geographical coordinates. Of these, approx. 3600 place names are identified with today’s places or topographical features. These serve as control points for the transformation of the hitherto unknown location data into today’s geographical coordinate system (WGS84). The article describes the historical data sources, the measurement methods of the time as well as previous and new transformation methods, discussing the special problems of the Geography and possible causes of transformation errors.

H έννοια της αξιοπιστίας σε ένα πρόβληµα εκτίµησης σχετίζεται µε τις αρχικές υποθέσεις που αφορούν στις µετρήσεις, στις µαθηµατικές σχέσεις που συνδέουν τις µετρήσεις µε τις επιλεγµέ-νες άγνωστες παραµέτρους και στη διαδικασία υπολογισµού αυτών των παραµέτρων. Αν αυτές οι αρχικές υποθέσεις δεν ισχύουν, τότε η ολική διαδικασία οδηγείται σε λανθασµένα αποτελέ-σµατα. H ορθότητα των αρχικών υποθέσεων καθώς και κάθε στατιστική υπόθεση σχετική µε τα αποτελέσµατα της ανάλυσης των παρατηρήσεων και της εκτίµησης των αγνώστων παραµέ-τρων, ελέγχεται µε την εφαρµογή του στατιστικού ελέγχου της γενικής υπόθεσης. Επειδή στις συνήθεις εφαρµογές η πιο συνηθισµένη αιτία για αναξιόπιστα αποτελέσµατα είναι τα σφάλµατα των µετρήσεων, για το λόγο αυτό και η έννοια της αξιοπιστίας συνδέεται κυρίως µε την ύπαρξη χονδροειδών σφαλµάτων στις µετρήσεις. Στην περίπτωση ειδικών εφαρµογών όπου απαιτείται υψηλή ποιότητα αποτελεσµάτων, είναι εξίσου σηµαντική η αξιολόγηση της αξιοπιστίας κάθε στατιστικού ελέγχου που εφαρµόζεται στα αποτελέσµατα της εκτίµησης και των σχετικών υπο-λογισµών. Στην εργασία αυτή αρχικά γίνεται αναφορά στην αξιοπιστία της σάρωσης δεδοµέ-νων, αλλά η έννοια της αξιοπιστίας επεκτείνεται και στον έλεγχο της γενικής υπόθεσης, όπως εφαρµόζεται στην ανάλυση των µετρήσεων και την εκτίµηση των αγνώστων παραµέτρων. Λέξεις κλειδιά: στατιστικός έλεγχος, σάρωση δεδοµένων, εσωτερική αξιοπιστία, εξωτερική αξιο-πιστία. Abstract The reliability related to an estimation problem, is associated with the initial assumptions about the measurements, the mathematical relationships that link the measurements to the unknown parameters selected and finally, the process of calculating these parameters. If these initial assumptions are not valid, then the whole process led to incorrect results. The accuracy of the initial assumptions and any statistical assumption on the results of the analysis of observations and assessment of unknown parameters, are all controlled by the application of statistical testing of the general case. For usual applications (with average accuracy standards), the most common cause of unreliable results is the errors in the measurements. Therefore, the concept of reliability is mainly linked to the existence of coarse errors in measurements. On the other hand, in the case of special applications which demand high accuracy standards, it is equally important to assess the credibility of any statistical test applied to the results of the assessment and calculation. This paper initially refers to the reliability of the data snooping, but the concept of reliability is extended to test the general case (general hypothesis), as applied both to the analysis of measurements and to the estimation of unknown parameters.

It is a summary of the 4 notes written by Engineer A. Fontaine, from the French National Geographic Institute, about the analysis of the Tunisian Primordial Terrestrial Geodetic Network concerning its orientation and scale. This investigation was realized during the period June 1987- January 1988.

One of the most crucial issues in engineering of structure and investigating ground deformation is deformation monitoring. The only thing which is strongly required is to create microgeodesy networks. An essential issue in microgeodesy networks is detecting unstable points of network. L1-Norm minimization and the global congruency can be noted as one of the classical methods for identifying network unstable points. In all previously conducted studies regarding this issue, results distinctly demonstrates that when displacement point vector is small, the number of points which have really displaced is more than that of true detection of displaced points using common deformation analysis ways. The probable reason for that can refer to spreading nature of the least squares estimation. Considering the results of recent studies in the detecting the network unstable points, to tackle the limitation the idea of subnetwork analysis is offered. In this case, some subnetworks including a subject point and the other source points appeared from dividing the deformation monitoring network. According to the unstable points, subnetworks will be there. This method will enable us to investigate the stable and unstable points. Having divided whole network to subnetworks, each network would be adjusted and unstable points of it would be detected. So, unstable points and their relations are cutoff and spreading effect of the least squares is fallen. This paper is on effort to evaluate the method in a simulated and a real network. The results prove that in a better and correct detection of unstable point can be successfully achieved by using subnetwork analysis compared to global congruency test all stimulates states proved the 35% of improvement on average. One percent of improvement in the results of subnetwork method to L1-Norm minimization cannot be acceptable. The algorithms of detecting unstable points in common methods and the method of analyzing subnetwork were conducted on a real network and the results are in line with simulated network results.

Jeodezik izleme ağlarında duyarlılık analizi genellikle, ilgili ağda beklenen yerdeğiştirmeleri öngörülmüş hata olasılıklarıyla saptamaya uygunsa, belirlenebilecek en küçük yerdeğiştirmelerin belirlenmesi veya ortaya çıkarılmasını sağlar. Bu çalışma ile jeodezik ağlarda datum sayısına bağlı belirlenebilecek en küçük deformasyon büyüklüklerinin belirlenmesi için duyarlılık analizi yapılmıştır. Bu amaç doğrultusunda, 13 noktalı bir jeodezik ağda gerçekleştirilen doğrultu ve kenar ölçüleri kullanılmıştır. Datum tanımına katkı sağlayan noktalara en uzak olan noktada yakalanabilecek en küçük deformasyon en büyük olarak berlirlenmiş ve datum noktalarının sayıları arttıkça yakalanabilecek en küçük deformasyon büyüklüğünün de azaldığı görülmüştür. Başka bir ifadeyle, referans noktalarına en uzak nokta en küçük yerdeğiştirmeye sahiptir. Ayrıca, yerdeğiştirme büyüklükleri ağdaki referans noktaları arttıkça azalmaktadır.

Rapid developments in engineering structures, the growing interest in studying the earth crust
movements, the analysis of deformation measurements, measurement methods and precision have
revealed new demands. The purpose of this study is to determine the deformations that take place on
dam crest due to different water level, load and dam’s body weight. Altinkaya Dam, which is a rock fill
dam, was selected as application area and a deformation network consisting of 6 references and 11
object points were constructed. In this study, deformation measurements were performed between 2000
and 2002. Measurements were made every June and September, in that the water level was minimum
and maximum, respectively. Hence, measurements were made in 4 periods. All measurements were
performed using static GPS measurement method. In this study, Iterative weighted transformation
(IWST), Least Absolute Sum (LAS), Congruency test analysis method and Fredericton were used for
performing two dimensional deformation analyses.

Continuous and campaign-style Global Positioning System (GPS) measurements provide new constraints on the first-order current deformation pattern of the northern Cordillera of NW Canada and eastern Alaska. The Yakutat block is currently colliding with North America in the corner of the Gulf of Alaska. Our data infer that relative Yakutat-North America motion is accommodated across the eastern boundary by right-lateral motion (˜40 mm/a), mainly on the Fairweather fault, and minor shortening (˜6 mm/a). To the north, collision is taken up by shortening (˜31 mm/a) mainly on the Chugach-St. Elias fault system, with westward extrusion and possible counterclockwise rotation of the Yakutat block and Alaskan fore arc facilitated by ˜23 mm/a right-lateral motion that is shared by several faults. The seismicity pattern indicates that plate boundary deformation is far reaching, producing strain throughout eastern Alaska, Yukon, and western Northwest Territories. Our GPS data confirm the transfer of strain from the Yakutat collision zone and enable the extent of plate boundary deformation to be mapped, thereby defining the western edge of "stable" North America. GPS sites in SW Yukon show motion of 3-10 mm/a to the NE, confirming that strain is transferred at least 400 km from the Yakutat collision. Continued transfer north toward the Mackenzie Delta and NE to the Mackenzie Mountains, indicated by current seismicity, is not yet well resolved by the campaign GPS data, which are hampered by coseismic and postseismic effects of the 2002 Mw 7.9 earthquake on the Denali fault in eastern Alaska.

Abstract: Although, there are various software that perform least squares adjustment of horizontal geodetic network so as to determine the precision and accuracy of the network. But the theories and equations that were used to develop the programs which the software are using are not quite understood by various user. This paper presents step by step procedures of horizontal geodetic network precision and accuracy determination using observation equation method of least squares technique. The detailed procedures are enumerated in sequential order for users understanding. The enumerated procedures are also demonstrated using a numeric example.

Dams are important engineering structures, therefore dams should be constructed with the rigors of safety in mind. In this paper, the vertical displacement of the crest of Keban Dam in Turkey, is determined using a grey prediction method. The grey prediction method is a method that produces satisfactory results when we do not have enough experience about a system behaviors. The purpose of this study is to examine the effectiveness of the grey prediction method in systems where a limited amount of data is available or known. In this study the Simple Exponential Smoothing (SES) method; a very well-known prediction method is used for comparison. The results from our investigation indicate that the grey prediction method produces better results, more in-keeping with true values.

Correct interpretation of surface stresses and deformation or displacement during volcanotectonic episodes is of fundamental importance for hazard assessment and dyke-path forecasting. Here we present new general numerical models on the local stresses induced by arrested dykes. In the models, the crustal segments hosting the dyke vary greatly in mechanical properties, from uniform or non-layered (elastic half-spaces) to highly anisotropic (layers with strong contrast in Young's modulus). The shallow parts of active volcanoes and volcanic zones are normally highly anisotropic and some with open contacts. The numerical results show that, for a given surface deformation, non-layered (half-space) models underestimate the dyke overpressure/thickness needed and overestimate the likely depth to the tip of the dyke. Also, as the mechanical contrast between the layers increases, so does the stress dissipation and associated reduction in surface stresses (and associated fracturing). In the absence of open contacts, the distance between the two dyke-induced tensile and shear stress peaks (and fractures, if any) at the surface is roughly twice the depth to the tip of the dyke. The width of a graben, if it forms, should therefore be roughly twice the depth to the tip of the associated arrested dyke. When applied to the 2009 episode at Harrat Lunayyir, the main results are as follows. The entire 3-7 km wide fracture zone/graben formed during the episode is far too wide to have been generated by induced stresses of a single, arrested dyke. The eastern part of the zone/graben may have been generated by the inferred, arrested dyke, but the western zone primarily by regional extensional loading. The dyke tip was arrested at only a few hundred metres below the surface, the estimated thickness of the uppermost part of the dyke being between about 6 and 12 m. For the inferred dyke length (strike dimension) of about 14 km, this yields a dyke length/thickness ratio between 2400 and 1200, similar to commonly measured ratios of regional dykes in the field.

The Puli Basin, located between the Western Foothills and the Hsüehshan Range is the largest basin in the active orogeny in central Taiwan. South to the Puli Basin, a series of small basins spread along the NNE direction. Various tectonic models have been proposed in previous studies to interpret the formation of the Puli Basin. In this study, we aim to measure the deformation and to understand the tectonics of Puli Basin by the method of satellite remote sensing and field observation. We applied the Persistent Scatterer Interferometric SAR technique to monitor the surface deformation. Our result shows a relative lower LOS velocity in Puli Basin, which implies the change of depth of the subsurface basal detachment. A steep ramp along the detachment is proposed for the grown structure underneath the Puli Basin in this study. In order to interpret the mechanism of surface deformation in central Taiwan, we implement several forward models based on previous researches and our interferometric results and then compare our observations with accurate GPS and precise leveling data. These results can be compared with our field observations and with the recent seismicity data (20130327 and 20130602) to examine the activity and geometry of faults of this area, where a conjugate fault system below the basins was suggested. Due to the lack of evidence, the relationship between the conjugate system and the basin subsidence mechanism is hard to determine but may be the key to understand the tectonic activity in central Taiwan.

Trilateration networks in 2D and 3D space, ranging from a local to a global scale, are continuously designed and established with a wide variety of objectives such as: cartographic, geodynamics, civil engineering, cadastral among others, using Geotechnologies through – for example - receivers which operate with the Global Positioning System (GPS) among others Global Navigation Satellite Systems (GNSS).
To evaluate the quality of the trilateration network is fundamental to characterize properly the Geodetic Reference Frame (GRF) given in the adjustment solution by the adjusted network point coordinates.
The geodetic datum definition is the set of all conventions, algorithms and constants necessaries to define and realize the origin, orientation, scale and their time evolution of a Geodetic Reference System (GRS), in such a way that these attributes be accessible to the users through occupation, direct or indirect observation.
In this work, we deal with the adjustment of a two-dimensional trilateration network constituted by physical points, where distances between these points have been observed. 
For the network adjustment, it is used a coordinate based formulation in a no stochastic linear model through a underdetermined consistent system of indirect linear observational equations.
The network point positions are defined in a Geodetic Reference System of Cartesian Coordinate (x,y) :GRS(x,y).
The GRS(x,y) is characterized by : a) right-handed convention is adopted for the axis; b) the origin is a point not specified of the Earth ; c) the ox (+) and oy(+) axis do not have specified orientations; d) the scale or length defined of the unit vectors along ox and oy is the meter (SI), and it is realized by the observed distances of the trilateration network.
The lack of definition in the origin and orientation of the GRS(x,y) cause a datum defect and a rank-deficiency  in the design matrix. 
A solution to the adjustment of the trilateration network called Minimum Norm Solution with respect to the R –seminorm (R-MINOS) of the underdetermined consistent system of indirect linear observational equations is obtained based in optimum criterions.
In this work, the Geodetic Reference Frame (GRF) of the solution R-MINOS in the adjustment of a trilateration network is characterized when R is the identity and a positive semidefinite matrix respectively.
As a numerical example, the GRF of the solution R-MINOS is characterized in the adjustment of a two-dimensional trilateration network with six points.