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Studies have suggested various solutions for determining the center coordinates and radius of a circle curve that are desired to pass through points whose coordinates are known. One solution is via adjustment according to the least-squares method based on the radius length. Another is based on the indirect measurement method, where the condition equation between the unknowns depends on the polar coordinate values of the points given in the radius equation. The center of the orthogonal coordinate system forms a triangle with the points that the circular curve is to pass through. Here, the distance between the center of the curve and the point where the circular curve is to be passed is the sought radius (R). From the points whose orthogonal coordinates are given, the approximate coordinates of the curve center can be calculated by the geodetic positioning method. In this case, the edge length between the center of the orthogonal coordinate system and the center of the curve and the point where the curve is to be passed is calculated. The break angle between the two sides is determined by means of the azimuth angles calculated according to the center of the Cartesian coordinate system of these two points. The radius R can be calculated using the cosine theorem in plane trigonometry. If the number of points that the curve is desired to pass is more than three, the determination can also be performed through adjustment computation. In this study, how to apply the cosine theorem to determine the circular curve elements is first explained. Then, two new algorithms are presented based on the cosine theorem, being inspired from the proposals given in two previous works. Both algorithms were applied to the numerical data given in the previous works, and the results were given comparatively. Finally, a new numerical example was solved, and the findings were examined. Comparing the solution method according to the proposed alternative cosine theorem with the Ghilani & Wolf and Niemeier approaches for curves with a radius of 2 to 3 km, it is seen that the curve parameters difference is a few decimeters in the Gauss–Markov adjustment computation method, while it is a few centimeters in the Gauss–Helmert adjustment computation method. However, for 100 m radius of the curves, the differences were determined to be a few centimeters in both adjustment computation methods. The precision criterion for the parameters determined by the surveying engineers by calculation is determined in centimeter size independent from the radius size with the proposed cosine theorem solution, thus increasing the reliability of the parameters. [ABSTRACT FROM AUTHOR]

This article focuses on a specially designed steel beam testing apparatus to determine the dynamics of the structure using data obtained from different sensor systems. The analysis of these different sensor systems is performed by processing data recorded by the Global Navigation Satellite System (GNSS), vision based measurement (video camera), and accelerometer surveys. To perform this analysis, the accelerometer and GNSS receiver are installed at the steel beam's mid-span position. The high-contrast artificial target attached to the accelerometer is recorded by a video camera to monitor the structural dynamics. Steel beam experiments show that it is compatible with the accelerometer, which is predicted as a reference sensor in detecting motion with an amplitude of 10 mm and above in the vertical direction with GNSS and determining the structural frequency by spectral analysis. On the other hand, we concluded that the video camera can be used to determine the structural dynamics in SHM because its results were compatible with the reference data even if the amplitude was too small. [ABSTRACT FROM AUTHOR]

Before the application, the coordinates of the circle shaped seat places that will be applied in indoor space can be obtained by the help of common points determined in numerical project model formed in a local coordinate system. Practically, the coordinates of the points in the digital project model can be also obtained numerically by using the coordinates of the common points. However, converting to numerals manually, the factors such as the support quality of the project, exhaustion of the operator, hand tremble and screen resolution influence the sensitivity of the conversion to numerals. Errors made during the conversion negatively affect the coordinates of the points. The most suitable method not to make errors is the calculation of coordinates of the points in the project model by geodetic method. In this project, the calculation of the coordinates of the seat midpoints placed on the curves in a closed area, benefited from the corner point coordinates of the seats in the indoor space obtained from geodetic measurement in a local coordinate system before the application and benefited from the data of the other points of the indoor space are explained. Furthermore, the ground application of the midpoints of the seats on each curve row is explained. The accuracy of the stake-out of seats in the conference room is obtained between 1 and 2 cm. [ABSTRACT FROM AUTHOR]

Applications in geodesy and engineering surveying require the determination of the heights of the vertical control points in the national and local networks using different techniques. These techniques can be classified as geometric, trigonometric, barometric and Global Positioning System (GPS) levelling. The aim of this study is to analyse height differences obtained from these three techniques using precise digital level and digital level, total station (trigonometric levelling) and GPS which collects phase and code observations (GPS levelling). The accuracies of these methods are analysed. The results obtained show that the precise digital levelling is more stable and reliable than the other two methods. The results of the three levelling methods agree with each other within a few millimetres. The different levelling methods are compared. Geometric levelling is usually accepted as being more accurate than the other methods. The discrepancy between geometric levelling and short range trigonometric levelling is at the level of 8 millimetres. The accuracy of the short range trigonometric levelling is due the reciprocal and simultaneous observations of the zenith angles and slope distances over relative short distances of 250 m. The difference between the ellipsoidal height differences obtained from the GPS levelling used without geoid and the orthometric height differences obtained from precise geometric levelling is 4 millimetres. The geoid model which is obtained from a fifth order polynomial fit of the project area is good enough in this study. The discrepancy between the precise geometric and GPS levelling (with geoid corrections) is 4 millimetres over 5 km. [ABSTRACT FROM AUTHOR]

Malaysia Airlines Flight 370, which was flying from Kuala Lumpur, Malaysia, to Beijing, China, lost communication with air traffic control shortly after take-off on March 8, 2014, and vanished. While the rest of the world awaited news of the missing plane and the 239 people on board, officials and experts began to look into the limited information available concerning the airliner's real activities. The disappearance of a Malaysia Airline flight, carrying 239 passengers and crew, is one of the world's biggest aviation mysteries. Despite all the efforts and evidence obtained so far, the crash site of Malaysia Airlines Flight MH370 could not be determined exactly. In this study, which we have done, the crash zone of the aircraft has been determined approximately by using the data in the previously prepared reports. In addition, the average ocean current speeds, directions and the parts of the debris of the aircraft were investigated on the satellite images, and the estimation of the area where the plane crashed was tried to be strengthened. [ABSTRACT FROM AUTHOR]

The effect of global warming on the southern polar regions necessitates careful monitoring of glacier deformations and their movements, as well as an understanding of atmospheric physics. For this purpose, the yearly movements of UNAVCO stations-South Pole Station (AMU2) (winter-summer) and other stations in the South Pole region have been observed in this paper for about a fifteen-year period (2006–2021). In addition, the area differences of the Antarctic continent due to seasonal changes (winter-summer) between 1980 and 2021 were investigated in this study. Moreover, the height values of the stations on the Antarctic continent were observed seasonally. The subglacial lakes in the Antarctic continent cause the differences in the height values as a result of the seasonal changes. A decrease in sea ice of 0.91 million km² for the winter season and 0.55 million km² for the summer season during a 41-year period has been determined for four sectors of the Antarctic continent. The temperature changes on the Antarctic continent in the summer and winter seasons (2005–2022) were also evaluated in this paper. Air temperature increases was apparent especially in the Antarctic Peninsula, East Antarctic and West Antarctic coasts. The Weddell Sea and the Amundsen Sea regions have had the most sea ice loss, each with 1.24 million km². On the other hand, it can be observed that the East Antarctic sector has expanded by 0.32 million km². [ABSTRACT FROM AUTHOR]