Теоретические основы построения и охраны геодезических сетей Туркменистана

The State Geodetic Network of Turkmenistan is necessary to ensure the dissemination of relevant coordinate data and elevation marks throughout the country. This network is the main geodetic basis for topographic surveys of all scales and is necessarily used in solving specific scientific and engineering tasks. The geodetic network covers the entire territory of the country with an appropriate density and is characterized by significant accuracy in determining the position of the required points [1].

The most important task of geodesy and cartography in modern conditions is to provide authorities and interested persons with cartographic materials and the results of geodetic measurements to solve state tasks to improve the functioning of the economy and the security of the country, the land complex and other areas.

One of the goals of creating a geodetic network is the formation of the state register of real estate. At the same time, the geodetic basis of the state cadastre of real estate is the state geodetic network and geodetic networks of special purpose (reference networks). Relevant information on the geodetic basis of the cadastre, obtained as a result of work on the creation of new or updating the existing geodetic basis of the cadastre, including the creation of new or restoration of lost points of the state geodetic network, reference networks, are entered in the state real estate cadastre.

Points of the state geodetic networks (astronomical-geodetic, geodetic, leveling and gravimetric), including geodetic points placed on lighthouses, navigation signs and other engineering structures, belong to state property and are under state protection. The regulations on the protection of geodetic network points are approved by the Cabinet of Ministers of Turkmenistan. Allotment of land plots for the placement of points of geodetic networks is carried out in accordance with the legislation of Turkmenistan.

The main qualitative parameters that ensure the effectiveness of the development of geodetic works are the accuracy and density of the geodetic basis. It is difficult to overestimate the importance of geodetic points, because without them neither geodetic, cartographic, nor construction and other works are possible. If we take it as a whole, then we are talking about the economy and national economy of the country, as well as industry [2, 3].

Geodetic networks are a set of fixed points on the earth's surface (geodetic points), the position of which is determined in a common system of geodetic coordinates for them.

Geodetic points are special objects designed to create and maintain a geodetic network. They are necessary to determine the exact coordinates and elevations, as well as to ensure the accuracy and reliability of geodetic measurements.

There are various types of geodetic points, each of which has its own unique characteristics and features. One of the most common types are geodetic ordinary points. They are support rods made of concrete or metal, installed on the ground and marked with special signs [4].

Another type of geodetic points are geodetic stations. They serve to perform accurate measurements and orientation in space. Geodetic stations are usually placed on high places, such as hills or mountains, to ensure maximum visibility and accuracy of measurements.

There are also specialized types of geodetic points, such as triangulation and leveling points. Triangulation points are used to determine the geographical coordinates and orientation of objects over long distances. Leveling points, in turn, serve to determine the height difference and create geodetic networks of altitude reference [5].

The most important requirement for the centers of geodetic points of the state geodetic network of our country is the preservation of the center and the immutability of its position in the ground in plan and height for a long time, and regardless of the class of the network. To fulfill this requirement, the centers are made of high-strength building materials: reinforced concrete pylons and piles, asbestos cement and metal pipes covered with anticorrosive agents. The base of the center is fixed with an anchor device and laid below the boundary of soil freezing. Special attention should be paid to the protection of the center from corrosion, as well as protection from the accumulation of water near the upper part of the center [6].

Demolition of external signs or remortgaging of the centers of geodetic points of state geodetic networks are carried out by the body authorized to carry out state management of geodetic and cartographic activities, or with its permission. State land users, owners of land plots on the rights of private ownership or lease, on the territory of which the points of state geodetic networks are located, are obliged to ensure their safety and, in case of damage or destruction, notify the body authorized to carry out state management of geodetic and cartographic activities, as well as provide an opportunity to access the points of state geodetic networks during geodetic and cartographic works [7].

Triangulation is a method in which a network of points is formed by constructing spatial triangles in which all angles and several sides are measured, called basic sides. Usually there are several points with known coordinates. Quite a long time the main method of constructing the state geodetic network is triangulation method (three angles). The features of this method can be well represented by the example of a chain of triangles. In each triangle, all angles are measured, and in the extreme triangles, one side is also measured. Triangulation networks can be in the form of a chain of triangles, a solid network, geodesic quadrangles, inserts into a hard corner, and others. The triangulation method finds application in the event that it is necessary to provide large areas with defined points, while maintaining high accuracy in determining the relative position of points.

Modernization of the centers in the near future should go in the direction of replacing concrete and metal pipes with pipes made of polymer materials, as more resistant to their destruction by processes occurring in the environment. Concrete monoliths can be replaced with asbestos cement pipes of suitable size filled with cement mortar. Such pipes will be cheaper and more convenient for laying and transportation than concrete monoliths and iron pipes. However, concrete centers, with all their advantages, have a significant mass, require compliance with a certain regime in laying and high-quality materials for their manufacture.