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.
Pierre Peytier refers to a French geologist and engineer, known for his contributions to the study of geology in the 19th century. He is particularly noted for his work in the fields of geology and mining, as well as for his research on the geological structures and resources in France, particularly in the region of the Pyrenees.
A planetary coordinate system is a method used to specify locations on the surface of a celestial body, such as a planet, moon, or asteroid. Similar to how geographic coordinates (latitude and longitude) specify locations on Earth, planetary coordinate systems provide a framework for identifying positions on other celestial objects. ### Key Features of Planetary Coordinate Systems: 1. **Coordinate Types**: - **Planetocentric Coordinates**: These use the center of the planet as the origin.
Polar motion refers to the movement of the Earth's rotation axis in relation to its crust, specifically the shifting position of the North and South Poles. This phenomenon is primarily influenced by various geophysical factors, including changes in atmospheric pressure, ocean currents, and how mass is distributed on and within the Earth. The Earth's rotation axis does not remain fixed; it experiences small oscillations and shifts over time.
Polar wander refers to the movement of the Earth's magnetic poles over time, which is different from the movement of the geographic poles. This phenomenon can occur due to changes in the Earth's mantle and crust, which can cause shifts in tectonic plates and changes in the distribution of mass within the Earth. As a result, the position of the magnetic poles can shift significantly over geological timescales.
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.
The Prime Meridian is an imaginary line that is defined as 0 degrees longitude. It serves as the reference point for measuring longitude and divides the Earth into the Eastern and Western Hemispheres. The Prime Meridian runs from the North Pole to the South Pole and passes through several countries, with its most commonly recognized location being at the Royal Observatory in Greenwich, London, England. The establishment of the Prime Meridian at Greenwich occurred in 1884 during an international conference in Washington, D.C.
Pseudorange is a term used in satellite-based positioning systems, such as Global Positioning System (GPS), to describe the calculated distance between the satellite and the receiver. It is called "pseudorange" because it is not an exact distance; rather, it is an estimate that accounts for several factors. The pseudorange is determined by measuring the time it takes for a signal to travel from the satellite to the receiver and then multiplying that time by the speed of light.
RINEX
RINEX, which stands for Receiver Independent Exchange Format, is a standard data format used for the exchange of satellite navigation system data. It was developed to allow different types of GNSS (Global Navigation Satellite Systems) receivers to share data, ensuring compatibility and interoperability among various manufacturers and systems. The RINEX format is primarily used for storing observations and navigation messages from GNSS satellites, including GPS, GLONASS, Galileo, and BeiDou.
Rauenberg is a district located in the borough of Treptow-Köpenick in Berlin, Germany. It is primarily a residential area with a mix of housing, green spaces, and local amenities. The district is characterized by its suburban feel, offering a quieter environment compared to the more densely populated areas of central Berlin. It is often appreciated for its community atmosphere and accessibility to natural landscapes, such as parks and rivers nearby.
Remote sensing is the science and technology of obtaining information about objects or areas from a distance, typically using satellite or aerial sensor technologies. It involves collecting data about the Earth's surface and atmosphere without physical contact, allowing for the study of various phenomena, such as land use, vegetation cover, climate change, and natural disasters. The process of remote sensing can be broken down into several key components: 1. **Sensors**: Remote sensing devices can be passive or active.
Rhumb line
A rhumb line, or loxodrome, is a path on the surface of a sphere (such as Earth) that crosses all meridians at the same angle. In simpler terms, it's a curved line that maintains a constant compass bearing, allowing a navigator to steer a constant angle relative to true north. Rhumb lines are significant in navigation because they provide a means to plot a course that simplifies travel over long distances.
The SK-42 reference system, also known as the "Soviet Calendar" or "Soviet Era," is a calendar system that was used in the Soviet Union. The SK-42 system is based on the Gregorian calendar but has a few modifications specific to the Soviet context. One of the notable features is that it emphasizes the Soviet era, starting from the year 1917, which is marked by the Bolshevik Revolution.
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 Schiehallion experiment, conducted in the late 18th century, was a notable geodetic survey designed to measure the gravitational attraction of a mountain, specifically Schiehallion in Scotland. Initiated by the mathematicians Nevil Maskelyne and his assistant, the experiment aimed to determine Earth's density and provide insights into gravitational measurements.
Sea level
Sea level refers to the average height of the ocean's surface, which serves as a baseline for measuring elevation and depth on Earth. It is considered a reference point for various purposes, including cartography, geography, and climate science.
Selenography is the scientific study of the Moon's surface and features. The term is derived from "Selene," the Greek goddess of the Moon, and "graphy," which means writing or description. This branch of astronomy involves the mapping and characterization of the Moon's physical characteristics, including its craters, mountains, valleys, and other geological features.
Snake Projection is a method used in cartography to represent geographic areas in a way that minimizes distortion, typically for the purpose of creating maps that help visualize spatial relationships more accurately. The technique involves creating a map projection that distorts the areas of shapes (like continents and countries) less than traditional projections. The idea is to “snake” the shapes across the map surface to ensure that their relative sizes remain more consistent with their true sizes on the globe.
Space geodesy is a branch of geodesy that uses satellite and space-based technologies to measure and monitor the Earth's shape, orientation, gravity field, and other geophysical phenomena. This field employs various techniques, including: 1. **Very Long Baseline Interferometry (VLBI)**: This method uses radio telescopes to measure the time it takes for signals from distant quasars to reach Earth.
A Spatial Reference System (SRS), also known as a Coordinate Reference System (CRS), is a system that provides a framework for spatial data to be identified, measured, and analyzed. It defines how geographic data is represented in a coordinate system and relates it to real-world locations. Here are some key components and concepts related to spatial reference systems: 1. **Coordinate System**: A spatial reference system uses a coordinate system to specify how points in space are represented.