The history of longitude describes the centuries-long effort by astronomers, cartographers and navigators to discover a means of determining the longitude of any given place on Earth. The measurement of longitude is important to both cartography and navigation. In particular, for safe ocean navigation, knowledge of both latitude and longitude is required, however latitude can be determined with good accuracy with local astronomical observations.
Finding an accurate and practical method of determining longitude took centuries of study and invention by some of the greatest scientists and engineers. Determining longitude relative to the meridian through some fixed location requires that observations be tied to a time scale that is the same at both locations, so the longitude problem reduces to finding a way to coordinate clocks at distant places. Early approaches used astronomical events that could be predicted with great accuracy, such as eclipses, and building clocks, known as chronometers, that could keep time with sufficient accuracy while being transported great distances by ship. Later methods used the telegraph and then radio to synchronize clocks. Today the problem of longitude has been solved to centimeter accuracy through satellite navigation.
Eratosthenes in the 3rd century BCE first proposed a system of latitude and longitude for a map of the world. His prime meridian (line of longitude) passed through Alexandria and Rhodes, while his parallels (lines of latitude) were not regularly spaced, but passed through known locations, often at the expense of being straight lines.cite book |last1=Roller |first1=Duane W. |title=Eratosthenes' Geography |date=2010 |publisher=Princeton University Press |location=Princeton, N.J. |pages=25–26 |isbn=978-1400832217 |url= |access-date=17 April 2020 By the 2nd century BCE Hipparchus was using a systematic coordinate system, based on dividing the circle into 360°, to uniquely specify places on Earth.
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642), commonly referred to as Galileo Galilei (ˌɡælᵻˈleɪoʊ_ˌɡælᵻˈleɪ , USalsoˌɡælᵻˈliːoʊ_- , ɡaliˈlɛːo ɡaliˈlɛi) or simply Galileo, was an Italian astronomer, physicist and engineer, sometimes described as a polymath. He was born in the city of Pisa, then part of the Duchy of Florence. Galileo has been called the father of observational astronomy, modern-era classical physics, the scientific method, and modern science.
In celestial navigation, lunar distance is the angular distance between the Moon and another celestial body. The lunar distances method uses this angle, also called a lunar, and a nautical almanac to calculate Greenwich time if so desired, or by extension any other time. That calculated time can be used in solving a spherical triangle. The theory was first published by Johannes Werner in 1524, before the necessary almanacs had been published. A fuller method was published in 1763 and used until about 1850 when it was superseded by the marine chronometer.
The history of longitude describes the centuries-long effort by astronomers, cartographers and navigators to discover a means of determining the longitude of any given place on Earth. The measurement of longitude is important to both cartography and navigation. In particular, for safe ocean navigation, knowledge of both latitude and longitude is required, however latitude can be determined with good accuracy with local astronomical observations.
Bases des références géodésiques, principe de mesure utilisé en localisation par satellites et de l'estimation de la qualité de positions GNSS (Global Navigation Satellites Systems).
Covers the implementation of an information system for managing taxi trajectories, including filtering data, creating trajectory models, and comparing performance.