Children: Geodesy
The Hayford ellipsoid, also known as the Hayford or International Ellipsoid of 1924, is a mathematical model of the Earth's shape that represents the Earth as an oblate spheroid. This ellipsoid was developed by the American geodesist, William H. Hayford, and was widely used for geodetic surveys and mapping in the early to mid-20th century.
Height Modernization refers to a comprehensive initiative aimed at enhancing how elevation data, particularly vertical positioning, is collected, managed, and utilized. This program often focuses on improving the accuracy and precision of height information, which is critical for various applications, including engineering, construction, navigation, natural resource management, and environmental science.
Height above mean sea level (often abbreviated as AMSL, or simply MSL) is a measurement of elevation or altitude that indicates how high a point is relative to the average sea level of the Earth's oceans. This average sea level is calculated over a long period and takes into account variations in tides, atmospheric pressure, and other factors.
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.
The Helmert transformation, also known as the Helmert method or Helmert coordinate transformation, is a mathematical procedure used in geodesy to convert coordinates from one geodetic reference frame to another. It is particularly useful for transforming 3D Cartesian coordinates and includes the effects of translation, rotation, and scaling. The standard Helmert transformation involves a linear map defined by a set of parameters that include: 1. **Translation**: Shifts coordinates along the X, Y, and Z axes.
Hermannskogel is the highest peak in the Vienna Woods (Wienerwald) located in Austria, near the city of Vienna. It has an elevation of approximately 542 meters (1,778 feet) above sea level. The mountain is part of the northern limestone Alps and is known for its natural beauty, lush forests, and recreational opportunities, including hiking and cycling.
Geodesy is the scientific discipline that deals with the measurement and representation of the Earth's geometric shape, orientation in space, and gravity field. The history of geodesy spans several millennia and can be divided into several key phases and developments: ### Ancient Period - **Early Measurements**: Geodesy has roots in ancient civilizations. The Egyptians and Babylonians made early attempts to measure distances and areas for agriculture and land ownership.
Horizontal position representation typically refers to the way in which spatial locations or coordinates are expressed along a horizontal axis in a given context, such as in graphs, mapping, or even data representation in certain fields like engineering or computer graphics. ### Key Points: 1. **Coordinate Systems**: In a Cartesian coordinate system, the horizontal position is represented by the x-coordinate. For example, in a 2D graph, a point’s horizontal position indicates its distance from the vertical axis (y-axis).
Interferometric Synthetic Aperture Radar (InSAR) is a remote sensing technique used to create high-resolution images of the Earth's surface and to measure ground deformation. It combines the principles of synthetic aperture radar (SAR) and interferometry to gain detailed insights into topography, land subsidence, tectonic activity, and other geological processes.
The Irish Transverse Mercator (ITM) is a geographical coordinate system used for mapping and spatial data in Ireland. It is based on the Transverse Mercator projection and is specifically tailored to minimize distortion across the island of Ireland. ### Key Features: 1. **Projection Type**: ITM is a cylindrical map projection that is particularly useful for areas with a greater north-south extent relative to their east-west extent. This allows for better accuracy in representing the geographical features of Ireland.
The Irish Grid Reference System is a geographic coordinate system used in Ireland to pinpoint locations on maps. It is based on the National Grid, which was established in the 1960s and is derived from the British National Grid system. The Irish grid coordinates are expressed in terms of a two-letter code followed by a numerical reference, which helps to provide a precise location.
The term "Israeli Cassini Soldner" refers to a specific variant of the Cassini-Soldner projection, which is a type of map projection used for representing geographic information. The Cassini-Soldner projection is a cylindrical map projection that is particularly suited for regions that are elongated in the north-south direction. In the context of Israeli mapping, the Israeli Cassini Soldner projection is used for topographic and geographic mapping in Israel.
The Israeli Transverse Mercator (ITM) is a map projection system used in Israel for geographic information systems (GIS), mapping, and surveying purposes. It is based on the Transverse Mercator projection, which is commonly used for mapping small areas with high accuracy.
The Jordan Transverse Mercator (JTM) is a specific geographical coordinate system used in Jordan, based on the Transverse Mercator projection. This type of projection is commonly employed for mapping and surveying purposes because it provides a good representation of smaller regions by minimizing distortion in distance, area, shape, and direction. The JTM is particularly useful for local and national mapping in Jordan, allowing for precise positioning and navigation within the country.
The Journal of Geodesy is a scientific journal that focuses on the field of geodesy, which is the science of measuring and understanding the Earth's geometric shape, orientation in space, and gravity field. It publishes research articles, technical notes, and reviews related to various aspects of geodesy, including satellite geodesy, geodetic measurements, Earth observation, geophysical applications, and the study of the Earth's crust and its dynamics.
The Journal of Spatial Science is a peer-reviewed academic journal that focuses on research and developments in the field of spatial science. This interdisciplinary journal covers a variety of topics including geographic information science (GIS), spatial data analysis, remote sensing, cartography, and related areas that analyze spatial relationships and patterns. It publishes original research articles, reviews, case studies, and discussions that contribute to the understanding of spatial phenomena and the methodologies used in spatial research.
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.
Least-squares adjustment is a mathematical method used to find the best-fitting solution to overdetermined systems of equations, where there are more equations than unknowns. This technique is commonly used in fields such as statistics, geodesy, computer vision, and various types of data fitting and analysis.
Levelling refraction refers to the bending of light rays in the atmosphere that can affect the measurements taken during surveying and leveling operations. When surveyors use leveling instruments to measure differences in height between points, the ideal assumption is that light travels in a straight line. However, atmospheric conditions, such as temperature and humidity variations, can cause light to bend, leading to discrepancies in the measurements.