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5TECHNOLOGY FOR CREATING SATELLITE GEODETIC NETWORKS Charyeva C.1, Kakabayeva M.2, Balzhayev P.3, Babayev D.4
'Charyeva Saadat - senior lecturer, 2Kakabayeva Myakhri - lecturer, 3Balzhayev Perkhat - student, 4Babayev Davut - student, TURKMEN STATE ARCHITECTURE AND CONSTRUCTION INSTITUTE ASHGABAT, REPUBLIC OF TURKMENISTAN
Abstract: the features of data collection for GPS surveys are considered. The main methods of transformation of coordinates from the WGS-84 ellipsoid into user coordinate systems have been studied. The main stages of the geodetic GPS network compilation are investigated.
Keywords: mathematical ellipsoid WGS-84, baseline, satellite data acquisition technologies, geodetic GPS networks.
The main method of data collection for all GPS surveys is by observing baselines. One receiver is placed at a known location, and the other at a location whose spatial position needs to be determined. Over a period of time, which depends on the specific shooting type, the baseline is observed, after which the receiver is moved to the next location. One of the main differences between GPS surveys and traditional geodetic surveys is that coordinates are calculated using the WGS-84 ellipsoidal model, rather than in a planned coordinate system. This means that the relative positions of the surveyed points are calculated relative to a set of base stations, which are transformed to the desired ellipsoid and projection system, such as the Krasovsky ellipsoid in a rectangular Gauss projection. There are several methods for converting coordinates from the WGS-84 ellipsoid to custom coordinate systems. The most common methods include the Molodensky method, the "7 parameter" method, and the method of spatial rotation of the network, as well as polynomial regression [1].
All calculations in GPS are performed in a geocentric coordinate system using the parameters of the WGS-84 mathematical ellipsoid, whose center coincides with the center of gravity of Earth. Unlike the lines used in traditional geodesy, the vector, also known as the BaseLine, is the result of processing GPS data. It is a line connecting the base station and the defined station relative to the center of the Earth on the WGS-84 mathematical ellipsoid. Several vectors together form a geodetic GPS network that covers the surface of the mathematical ellipsoid.
With the help of specialized software, the network can be accurately aligned. In some programs, it is even possible to combine GPS measurements with traditional geodetic measurements, and transform the coordinates of identified points into the Krasovsky Ellipsoid using an accepted cartographic projection. There are several technologies used to monitor vectors in a geodetic GPS network. These methods of collecting data from satellites differ in the accuracy of determining coordinates, observation time, and performance. However, there are some conditions that must be met for successful execution of any type of GPS survey: to perform geodetic GPS vector observations, it is necessary to ensure simultaneous operation of at least two GPS receivers, followed by combining their accumulated data. Simultaneous reception of a satellite radio signal from at least four satellites is required, which can be difficult in built-up or wooded areas. It is also important to avoid the presence of powerful working TV and radio broadcasting devices, especially those with a periscopic radio signal amplification scheme, as they can drown out or distort the satellite signal.
As a general rule, all GPS receivers have a navigation mode. In this mode, the receiver's display or controller continuously shows data about the spatial position, speed, and direction of movement of the receiver. It is also possible to enter coordinates of a destination point, which will show the distance, direction, and time to arrive if the receiver keeps moving at a constant speed [2, 3]. The operator can mark a standing point as special, which the receiver will remember in its internal memory. This method of navigation has the lowest accuracy but is useful for finding objects with known coordinates, such as the centers of geodetic points with destroyed signs, wells, and other underground utilities. Kinematic real-time surveying is used in situations where it is necessary to obtain coordinates directly on the ground. It can be used for making design decisions on terrain, conducting topographic surveys by drawing a plan on the spot, and other tasks. Static and fast-static surveys are the traditional and most common types of GPS surveys. These types of surveys provide very high accuracy in determining coordinates.
References
1. Антонович К.М. Использование спутниковых радионавигационных систем в геодезии. М.: 2006.
2. Гучгельдиев А., Ходжамов Т., Хемраев Н. Основные пути совершенствования картографического образования // Студенческий журнал.2024. № 2(256).
3. Kerimov K., Khodzhimuradov R.., Azadova A. Implementation of the concept of modern educational space in the projects of construction of new buildings of technical universities of Turkmenistan // Модели и методы повышения эффективности инновационных исследований. 2023 - Уфа.
