The Hellenic Geodetic Reference System 1987 (HGRS87) is a geodetic datum used in Greece for mapping and surveying. It was established to provide a consistent framework for geographic coordinate systems and geospatial data within the country. The system is based on the geodetic reference frame defined by the International Terra Reference Frame (ITRF), which was adapted to fit the specific geographical and geological conditions of Greece.

Latitude is a geographical coordinate that specifies the north-south position of a point on the Earth's surface. It is measured in degrees, with the Equator defined as 0° latitude. As you move towards the North Pole, the latitude increases up to 90°N, and as you move towards the South Pole, it decreases down to 90°S. Latitude lines are horizontal and run parallel to the Equator, and they indicate how far a location is from the Equator.

Maclear's Beacon is a prominent geographical feature located in the Drakensberg mountain range of South Africa. It is known for its distinctive shape and is one of the most recognized peaks in the area. The beacon itself is a rock formation that reaches an elevation of about 3,200 meters (10,500 feet) above sea level.

The term "map" can refer to several different concepts depending on the context. Below are some of the most common definitions: 1. **Geographical Map**: A visual representation of an area, showing physical features like mountains, rivers, and lakes, or political boundaries such as countries, states, and cities. Maps can be physical (printed on paper) or digital (viewed on a computer or mobile device).

The National Spatial Reference System (NSRS) is a framework in the United States that provides a consistent and accurate geospatial foundation for mapping and surveying activities. It is managed by the National Oceanic and Atmospheric Administration (NOAA), specifically through the National Geodetic Survey (NGS). The NSRS includes a set of geodetic control points, data, and standards that ensure the accurate representation of the Earth's geographic features for various applications, including engineering, construction, and environmental monitoring.

Physical geodesy is a branch of geodesy that focuses on understanding the Earth's shape, orientation in space, and gravitational field. It involves the measurement and interpretation of physical properties of the Earth to generate models that describe its size, shape, and gravitational influences.

A positioning system is a technological system designed to determine the location of an object in a particular space. These systems can be used in a variety of applications, including navigation, mapping, and tracking. ### Key Components and Types of Positioning Systems: 1. **Global Positioning System (GPS)**: The most well-known positioning system that uses a network of satellites to provide location and time information to a GPS receiver anywhere on Earth.

Satellite navigation is a technology that uses satellites to determine the precise geographic location of a receiver on or near the Earth's surface. This technology allows users to find their position using signals transmitted from satellites in orbit around the Earth. Satellite navigation systems operate by triangulating the signals from multiple satellites, which enables the calculation of the receiver's location in terms of latitude, longitude, and altitude.

The World Geodetic System (WGS) is a global reference system that provides a framework for geospatial data and mapping. The most widely used version is the WGS 84 (World Geodetic System 1984), which is employed by the Global Positioning System (GPS) and serves as a standard for cartography, geodesy, and navigation.

Tide can refer to several different things, depending on the context: 1. **Oceanography**: Tide refers to the regular rise and fall of sea levels caused by the gravitational forces exerted by the Moon and the Sun, combined with the Earth's rotation. Tides are typically observed in cycles of approximately 12 hours and can significantly influence coastal ecosystems and activities. 2. **Laundry Detergent**: Tide is a brand of laundry detergent produced by Procter & Gamble.

"Vertical" and "horizontal" are terms used to describe directions or orientations in space. 1. **Vertical**: - Vertical refers to a direction that is oriented up and down. It is perpendicular to the horizontal plane. In a typical Cartesian coordinate system, the vertical direction often aligns with the y-axis. For example, when you think of a tall building or a tree, those objects have a vertical orientation because they rise straight up toward the sky.

Boris Delaunay, also spelled as Boris Delaunay in some contexts, is primarily known as a mathematician who contributed significantly to the field of computational geometry. He is best known for the Delaunay triangulation, a method of dividing a set of points into triangles that maximizes the minimum angle of the triangles, avoiding skinny triangles. This triangulation is important in various applications, including computer graphics, geographic information systems (GIS), and finite element analysis.

Boyd Crumrine Patterson was an influential American lawyer and politician who served as a significant political figure in Pennsylvania. He was born on August 4, 1910, and passed away on March 23, 1991. Patterson was best known for his role as a member of the Pennsylvania House of Representatives, where he made contributions to legislative processes and local governance. He played a notable role in advocating for various issues during his tenure, helping to shape public policy in the state.

Børge Jessen is not specifically known as a widely recognized public figure, concept, or term in common knowledge up until October 2023. It is possible that Børge Jessen could refer to an individual, character, or a concept that is less commonly discussed or is specific to a certain region or context.

"Medieval geometers" typically refers to mathematicians and scholars during the Middle Ages who contributed to the field of geometry, building on the foundations established by ancient Greek mathematicians like Euclid, Archimedes, and others. The medieval period, roughly spanning from the 5th to the late 15th centuries, saw a mix of continued study in geometry as well as the transmission of knowledge from the Islamic Golden Age.

Arthur Moritz Schoenflies (1853–1928) was a German mathematician known for his contributions to geometry and crystallography. He is particularly recognized for the Schoenflies notation, which is a system used to describe the symmetry of geometric figures and molecular structures. This notation is part of his work in the study of symmetry operations and their applications in various fields, including physics and chemistry.

August Adler may refer to several different subjects, but without more specific context, it's difficult to determine exactly what you are asking about. There may be people, characters, or topics in literature, history, or current events associated with the name "August Adler.

Carl Anton Bretschneider (1813–1888) was a notable German botanist known for his contributions to plant taxonomy and botany. He is particularly recognized for his work on the flora of Central Europe. Bretschneider played a significant role in the study and classification of various plant species and is remembered for his meticulous research in the field.

David Gabai is a prominent American mathematician known for his contributions to the fields of topology and geometric topology. He has made significant advancements in understanding 3-manifolds, particularly through his work on the theory of hyperbolic manifolds and knot theory. Gabai is a professor at Princeton University and has received several prestigious awards for his research, including a MacArthur Fellowship. His work has helped to deepen the understanding of complex mathematical structures and has influenced various areas in mathematics.

Diane Maclagan is a notable mathematician and educator recognized for her work in the field of mathematics, particularly in algebraic topology and its applications. However, it's important to clarify that there may be limited publicly available information about her specific contributions.