The Arrow–Debreu model is a foundational concept in modern microeconomic theory, named after economists Kenneth Arrow and Gérard Debreu, who developed it in the 1950s. The model provides a formal framework for understanding general equilibrium in a competitive market and demonstrates the conditions under which an economy can achieve Pareto efficiency.

Kristine M. Larson is a notable figure in the field of geophysics and remote sensing, particularly known for her work on the application of GPS technology in monitoring seismic activities and understanding geophysical processes. She has contributed significantly to the understanding of Earth's crustal deformation and the dynamics of tectonic plates. Larson has also been involved in various research projects and has published numerous academic papers in her field.

Véronique Dehant is a prominent researcher known for her work in the fields of geodesy and geophysics. She has contributed significantly to the understanding of Earth’s gravitational field and its variations, as well as to studies related to the dynamics and structure of the Earth’s interior. Her research often involves using satellite data and other geophysical measurements to study phenomena such as sea-level rise, climate change, and Earth motion.

The U.S. National Geodetic Survey (NGS) is a division of the National Oceanic and Atmospheric Administration (NOAA) that is responsible for surveying and mapping the nation's geographic and geodetic data. Established in 1807, its primary mission is to provide accurate and reliable geospatial data and services that underpin various applications, including mapping, navigation, land use planning, resource management, and disaster response.

The history of geomagnetism is a fascinating journey that encompasses centuries of scientific inquiry and technological development. Here’s a concise overview of key milestones in the study of Earth's magnetic field: ### Ancient Beginnings - **Magnetite Discovery**: The magnetic properties of the naturally occurring mineral magnetite were known to ancient civilizations. The Greeks first described magnetic attraction around the 6th century BCE, with Thales of Miletus among those acknowledging its existence.

The International Latitude Service (ILS) is an international collaborative effort aimed at precise measurement and monitoring of the Earth's latitude changes. Established in the early 20th century, the ILS primarily focuses on tracking variations in latitude caused by factors such as tectonic activity, glacial rebound, and other geophysical processes. The service involves a network of observatories equipped with highly accurate astronomical instruments.

The French Geodesic Mission to Lapland, which took place in the 18th century, was a significant scientific expedition aimed at determining the shape of the Earth by measuring a meridian arc. Specifically, it was part of a larger effort to resolve the debate over whether the Earth was an oblate spheroid (flattened at the poles) or a prolate spheroid (elongated at the poles).

GIScience (Geographic Information Science) and Remote Sensing are two interconnected fields that deal with the analysis and management of spatial data. Here's a breakdown of each: ### GIScience (Geographic Information Science) GIScience is the study of geographic information systems (GIS) and encompasses the theories, techniques, and technology used to collect, analyze, and visualize spatial data.

The International Journal of Applied Earth Observation and Geoinformation is a peer-reviewed academic journal that focuses on research and developments in the fields of earth observation and geoinformation technologies. It publishes articles related to the application of remote sensing, geographic information systems (GIS), and other related technologies in various domains such as environmental monitoring, urban planning, disaster management, agriculture, forestry, and natural resource management.

The Japan Microgravity Centre (JMC) is an organization focused on conducting research and development in the field of microgravity and its applications. Established in Japan, the center serves as a platform for scientists, researchers, and industry professionals to explore the effects of microgravity on various physical, biological, and chemical processes. The center typically collaborates with various institutions, including universities and businesses, to facilitate experiments and promote innovation in areas such as materials science, life sciences, and space technology.

The Weyl distance function is a mathematical tool used in the field of differential geometry and the study of Riemannian manifolds. It is particularly important when analyzing the geometry of spaces that have different curvature properties. The concept is closely associated with Weyl's notion of conformal equivalence. In a more formal sense, the Weyl distance function can be defined within the context of Riemannian geometry.

A rational polynomial coefficient refers to a coefficient in a polynomial that is a rational number. A polynomial is typically expressed in the form: \[ P(x) = a_n x^n + a_{n-1} x^{n-1} + \ldots + a_1 x + a_0 \] where the \(a_i\) (coefficients) can be any real or complex numbers.

Geo-IK-2 is a Russian Earth observation satellite that is part of the Geo-IK program, which aims to provide geodetic and cartographic data for various applications, including environmental monitoring, natural resource management, and infrastructure planning. The satellite is equipped with high-resolution imaging capabilities and is typically used for surveying and mapping purposes.

The International Terrestrial Reference System (ITRS) is a global reference system for positioning and measuring locations on the Earth. It provides a standardized framework for defining the position and motion of points on the Earth's surface and within its geophysical environment. The ITRS is crucial for a wide range of scientific and practical applications, including geodesy, navigation, satellite positioning, and Earth observation.

The Luzon Datum of 1911 is a geodetic reference system established for the Philippines, specifically for the island of Luzon. It was created to provide a consistent framework for mapping and surveying the region. The datum serves as a base level for elevation measurements and is essential for accurate land surveys, infrastructure development, and other geospatial applications.

Vertical Offshore Reference Frames (VORF) refers to a system designed to provide a standardized way to measure and represent sea level changes and underwater topography in offshore environments. Understanding sea level is critical in various applications, including maritime navigation, offshore renewable energy, oil and gas exploration, and coastal management. Key components of Vertical Offshore Reference Frames include: 1. **Geodetic Foundations**: VORF systems are built upon precise geodetic measurements that establish reference points or benchmarks in offshore areas.

ANNA 1B, or ANNA 1B, is a designation referring to a specific celestial object that is a trans-Neptunian object (TNO) in the Kuiper Belt. It is part of a group of objects beyond the orbit of Neptune. These objects are of great interest to astronomers because they help in understanding the early solar system and its formation.

Etalon is a series of satellites that are part of a Russian space program aimed at providing high-precision geolocation and timekeeping services. Specifically, the Etalon satellites are designed to serve as part of the GLONASS (Global Navigation Satellite System) network, which is Russia's counterpart to the United States' GPS. The Etalon satellites enhance the accuracy of positional measurements and timing, which are crucial for various applications including navigation, surveying, and scientific research.

Subduction is a geological process that occurs at convergent plate boundaries, where one tectonic plate moves under another and sinks into the Earth’s mantle. This typically happens when an oceanic plate, which is denser, collides with a continental plate or another oceanic plate. The descending plate creates a subduction zone, characterized by deep ocean trenches, volcanic arcs, and earthquake activity.

The Falkland Islands and Dependencies Aerial Survey Expedition refers to a significant scientific and exploratory initiative aimed at conducting aerial surveys of the Falkland Islands and their surrounding territories. This type of expedition typically involves the use of aircraft equipped with cameras and other sensing technology to collect data about the geography, topography, and ecological characteristics of the islands and adjacent waters. The primary goals of such surveys often include mapping the terrain, assessing natural resources, monitoring environmental changes, and contributing to conservation efforts.