Sometimes scientific or other specific concepts are used in areas not related to the original. This happened with the geodetic term "reference point". According to the definition, a geodetic reference point is a mark or sign fixed at a specific point on the earth's surface. The coordinates and height of this place are calculated by leveling relative to a known and generally accepted value.
Level height systems
In Russia and some countries of the former USSR, the Kronstadt footstock is considered to be the zero mark for reading the surface level. All geodetic signs indicated on the maps of these countries are calculated according to the B altic system of heights adopted in 1977. In the regions of the Far East, calculations are carried out according to the Okhotsk system of heights. Its error relative to the BSV is less than one meter.
Footstock is a rail with divisions for determining the water level in a river or other body of water. Sometimes permanently installed footstocks, as reference points and reference points in geodesy, are used by scientists to observe changes in the water level in the seas, for the movements of the layers of the earth's surface along the vertical.
OhKronstadt footstock and determination of sea level
Initially, the change in the height of the water level of the Gulf of Finland was marked by horizontal notches on the walls of channels and basins, on the surfaces of locks. When a special service was organized in Kronstadt in 1777, water observations were carried out according to the marks of the footstock from the bottom of the Obvodny Canal.
Long-term (since 1731) and regular notes, observations of fluctuations in the water levels of the Gulf of Finland were processed by hydrographer M. F. Reinecke in 1840. hell. A few decades later, a metal plate with a horizontal mark was fixed at this level, practically coinciding with the zero reading of the footstock.
Transfer of sea level to land
This level indicator was transferred to the mainland territory by means of leveling along the St. Petersburg – Oranienbaum railway line and “tied” with a bolt mark to one of the buildings at the B altic Station. It is this bolt that has been the main reference point for all leveling measurements in the country since 1892.
In 1946, a unified system of coordinates and heights was introduced on the territory of the Soviet Union. The level of the B altic Sea with a mark corresponding to zero on the Kronstadt footstock was taken as the initial one. This is the control reference point of the state leveling system. From the absolute zero mark, heights and depths are calculated for all domestic maps and sailing directions,orbits for spacecraft flights.
Varieties of benchmarks in geodesy
On the ground, the reference point is indicated by a structure in the form of a pyramid of stones, boards or metal tubes. Depending on the purpose, there are several types of benchmarks:
- Centuries are distributed in accordance with a special scheme throughout the country. They are installed according to the instructions in the given geographical points. They are used mainly for scientific purposes.
- Fundamental are equipped on all leveling lines of the first class (between secular) and on the most important lines of the second class. The distance between the points is from 50 to 80 km. They are laid exclusively in the ground in the form of reinforced concrete pillars and pylons. Since the fundamental reference point can only be used in certain cases, an ordinary reference satellite with accurate transferred data is installed not far from it. It is used as a support for leveling grades 3 and 4.
- Ordinary benchmarks are wall, rock and ground. Fixed at a distance of 3.5 to 7 km from one another, these signs can be laid along all leveling lines.
The system of interconnected fundamental and ordinary reference points forms the GGS - the state geodetic network.
Cartographic designation of geodetic marks
Field point is marked with special icons on the maps. They are distinguished as follows:
- for astronomical points;
- for GHS items;
- for central points fixed in the territory;
- for survey network points;
- for points of the state leveling geodetic network.
All these points are marked on the real surface of the Earth with metal pyramids or ordinary benchmarks. Geodetic centers indicating the location of the point are applied to maps by coordinates, that is, as accurately as possible, with indications of elevation marks.
What is a reference point? Elevations included in the general geodetic network, mounds, hills or free-standing buildings with spiers, towers or bell towers are designated by conventionally accepted combined icons. GGS points in maps with a large scale indicate absolutely everything. Astronomical points that are landmarks are indicated only in cases where they are starting points in a given area.
Triangulation (reference) points, their setting
The installation of permanent signs is carried out by the State Geodetic Leveling Network. The ground parts of the benchmarks are mutually visible to each other at a certain distance. The design and height of the signs depend on the purpose, local conditions, soil and distances from one point to another.
Geodetic points can be made in the form of metal or wooden pyramids, stone or reinforced concrete pillars. The height of each structure depends on the binding location. Any benchmark serves as a tripod or support for the measuring tool and the observer.
The underground part of this design is made in the form of a concrete-filledfoundation monolith. A mark cast from metal is built into the point itself, which is the center of the point. The inscription on the latter indicates the number and type of this item. The name of the organization that performed the work and the year of installation are cast along with a mark (usually cast iron).
Building and reference marks
Disk-shaped benchmarks made by iron casting are installed in the walls of industrial buildings, locks, in the abutments and supports of bridges. This is done to monitor the static state of large structures. On disk stamps, in addition to inscriptions, there are protrusions intended for installing a leveling rail. The purpose of geodetic marks can be divided into the following categories:
- reference, or control, which is the basis for determining the position of established brands, taking into account safety and stability over time;
- auxiliary - these are intermediate signs for transferring coordinates and values between deformation and reference marks;
- deformation marks that are fixed directly on the walls of the observed structures or buildings (with spatial changes in the position of the object, these marks move with it).
Fixed points in construction are a guarantee of timely detection of the mobility or instability of a large object, such as a hydroelectric dam or a high-rise building.
Who needs all this
Thanks to the interconnected system of designated points, a state geodetic network is formed. Special catalogs contain lists with specified coordinates of all such points. This information is used by topographers to study the surface of the planet, in engineering and geodetic surveys, for various needs of the country's economy.
Lists indicating the values of the coordinates are brought to the officers of the army along with topographic maps. Artillerymen are also well aware that a reference point is a mark indicating a known height, a kind of support for zeroing in on the ground.
Reference points on the Celsius temperature scale are considered to be the values of boiling and freezing of water at sea level.
In business, this term is used to describe a state of affairs where certain actions can lead to either complete failure or success.
He alth, entrepreneurship
Since the reference point is a kind of reference indicator, a “hook”, this concept can be applied in many areas of human life.
Exploring the causes of frequent stress in people who constantly live in megacities, scientists have found that the unnatural visual environment is to blame. The distribution of right angles and lines, uniformly colored buildings, a large number of static objects negatively affects the emotional state of a person. A psychophysiological branch of science called visual ecology argues that the lack of distinctive features of architectural decorative elements overloads the optic nerve.
The eye must highlight, fix some point, detail, element in the visual space, so that the brain perceives the environment as comfortable, close to natural and harmonious. Only then does a person have a feeling of aesthetic and emotional satisfaction.
Fixed points in business are a kind of airbags. They can be used to increase the competitiveness of the enterprise. If we take as a basis some marketing techniques or the state of affairs in the current period, we can identify comprehensive measures that need to be taken to change the situation for the better.
