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Josef De Mendoza Y Ríos
Josef (also José or Joseph) de Mendoza y Ríos (1761–1816) was a Spanish astronomer and mathematician of the 18th century, famous for his work on navigation. The first work of Mendoza y Ríos was published in 1787: his treatise about the science and technique of navigation in two tomes. He also published several tables for facilitating the calculations of nautical astronomy and useful in navigation to calculate the latitude of a ship at sea from two altitudes of the sun, and the longitude from the distances of the moon from a celestial body. In the field of the nautical instruments, he improved the reflecting circle. In 1816, he was elected a foreign member of the Royal Swedish Academy of Sciences. Biography In 1787, De Mendoza published his first work, his treatise on the sciences and techniques of navigation in two volumes, a reference work of the time. After this, he proposed the creation of the maritime library, located in Cádiz, which would eventually become the ''D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sevilla
Seville (; es, Sevilla, ) is the capital and largest city of the Spain, Spanish autonomous communities of Spain, autonomous community of Andalusia and the province of Seville. It is situated on the lower reaches of the Guadalquivir, River Guadalquivir, in the southwest of the Iberian Peninsula. Seville has a municipal population of about 685,000 , and a List of metropolitan areas in Spain, metropolitan population of about 1.5 million, making it the largest city in Andalusia, the List of metropolitan areas in Spain, fourth-largest city in Spain and the Largest cities of the European Union by population within city limits, 26th most populous municipality in the European Union. Its old town, with an area of , contains three UNESCO World Heritage Sites: the Alcázar of Seville, Alcázar palace complex, the Seville Cathedral, Cathedral and the Archivo General de Indias, General Archive of the Indies. The Seville harbour, located about from the Atlantic Ocean, is the only rive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tables For Facilitating The Calculations Of Nautical Astronomy
Table may refer to: * Table (furniture), a piece of furniture with a flat surface and one or more legs * Table (landform), a flat area of land * Table (information), a data arrangement with rows and columns * Table (database), how the table data arrangement is used within databases * Calligra Tables, a spreadsheet application * Mathematical table * Table (parliamentary procedure) * Tables (board game) * Table, surface of the sound board (music) of a string instrument * ''Al-Ma'ida'', the fifth ''surah'' of the Qur'an, usually translated as “The Table” * Water table See also * Spreadsheet, a computer application * Table cut, a type of diamond cut * The Table (other) * Table Mountain (other) * Table Rock (other) * Tabler (other) * Tablet (other) Tablet may refer to: Medicine * Tablet (pharmacy), a mixture of pharmacological substances pressed into a small cake or bar, colloquially called a "pill" Computing * Tablet computer, a m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1761 Births
Events January–March * January 14 – Third Battle of Panipat: Ahmad Shah Durrani and his coalition decisively defeat the Maratha Confederacy, and restore the Mughal Empire to Shah Alam II. * January 16 – Siege of Pondicherry (1760) ended: The British capture Pondichéry, India from the French. * February 8 – An earthquake in London breaks chimneys in Limehouse and Poplar. * March 8 – A second earthquake occurs in North London, Hampstead and Highgate. * March 31 – 1761 Portugal earthquake: A magnitude 8.5 earthquake strikes Lisbon, Portugal, with effects felt as far north as Scotland. April–June * April 1 – The Austrian Empire and the Russian Empire sign a new treaty of alliance. * April 4 – A severe epidemic of influenza breaks out in London and "practically the entire population of the city" is afflicted; particularly contagious to pregnant women, the disease causes an unusual number of miscarriages and prema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflecting Instrument
Reflecting instruments are those that use mirrors to enhance their ability to make measurements. In particular, the use of mirrors permits one to observe two objects simultaneously while measuring the angular distance between the objects. While reflecting instruments are used in many professions, they are primarily associated with celestial navigation as the need to solve navigation problems, in particular the problem of the longitude, was the primary motivation in their development. Objectives of the instruments The purpose of reflecting instruments is to allow an observer to measure the altitude of a celestial object or measure the angular distance between two objects. The driving force behind the developments discussed here was the solution to the problem of finding one's longitude at sea. The solution to this problem was seen to require an accurate means of measuring angles and the accuracy was seen to rely on the observer's ability to measure this angle by simultaneously ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sextant
A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. The primary use of a sextant is to measure the angle between an astronomical object and the horizon for the purposes of celestial navigation. The estimation of this angle, the altitude, is known as ''sighting'' or ''shooting'' the object, or ''taking a sight''. The angle, and the time when it was measured, can be used to calculate a position line on a nautical or aeronautical chart—for example, sighting the Sun at noon or Polaris at night (in the Northern Hemisphere) to estimate latitude (with sight reduction). Sighting the height of a landmark can give a measure of ''distance off'' and, held horizontally, a sextant can measure angles between objects for a position on a chart. A sextant can also be used to measure the lunar distance between the moon and another celestial object (such as a star or planet) in order to determine Greenwich Mean Time and hence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Navigational Algorithms
The navigational algorithms are the quintessence of the executable software on portable calculators or PDA as an aid to the art of navigation, this attempt article describe both algorithms and software for ''"PC-PDA"'' implementing different calculation procedures for navigation . The calculation power obtained by the languages: Basic, "C", Java, etc. .., from portable calculators or PDAs , has made it possible to develop programs that allow calculating the position without the need for tables, in fact they have some basic tables with the correction factors for each year and calculate the values "on the fly" at runtime . Comparison between manual calculation methods and the use of calculators * The traditional methods require bulky and expensive nautical tables (which must be updated), pencil and paper, and calculation time, following the working algorithms. * Calculators (and the like) do not need books (they have tables and ephemeris integrated) and, with their own algorithms, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Almanac
A nautical almanac is a publication describing the positions of a selection of celestial bodies for the purpose of enabling navigators to use celestial navigation to determine the position of their ship while at sea. The Almanac specifies for each whole hour of the year the position on the Earth's surface (in declination and Greenwich hour angle) at which the Sun, Moon, planets, and First Point of Aries is directly overhead. The positions of 57 selected stars are specified relative to the First Point of Aries. In Great Britain, ''The Nautical Almanac'' has been published annually by HM Nautical Almanac Office, ever since the first edition was published in 1767. In the United States, a nautical almanac has been published annually by the US Naval Observatory since 1852. It was originally titled '' American Ephemeris and Nautical Almanac''. Since 1958, the USNO and HMNAO have jointly published a unified nautical almanac, ''The Astronomical Almanac'' for use by the navies of b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Sandglass
A marine sandglass is a timepiece of simple design that is a relative of the common hourglass, a marine (nautical) instrument known since the 14th century (although reasonably presumed to be of very ancient use and origin). Sandglasses were used to measure the time at sea or on a given navigational course, in repeated measures of small time increments (e.g., 30 minutes). Used together with the chip log, smaller marine sandglasses were also used to measure the boat speed through the water in knots. Although vital to maritime navigation, marine sandglasses were not accurate measuring instruments for the passage of time; many design and environmental factors could affect the duration of sand's flow, and therefore its reported time. Their use continued through the early 19th century, when they were supplanted by reliable mechanical timepieces, and by other advances in marine navigation. Marine sandglasses were very popular on board ships, as they were the most dependable measurement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Longitude
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. Finding an accurate and practical method of determining longitude took centuries of study and invention by some of the greatest scientists and engineers. After increasingly accurate methods based on astronomical observations and chronometers, today the problem of longitude has been solved to centimeter accuracy through satellite navigation. Longitude before the telescope 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haversine
The versine or versed sine is a trigonometric function found in some of the earliest (Sanskrit ''Aryabhatia'', Section I) s. The versine of an angle is 1 minus its cosine. There are several related functions, most notably the coversine and haversine. The latter, half a versine, is of particular importance in the of navigation. Overview The versine[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Navigation
Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space (or on the surface of the Earth) without having to rely solely on estimated positional calculations, commonly known as "dead reckoning", made in the absence of satellite navigation or other similar modern electronic or digital positioning means. Celestial navigation uses "sights", or timed angular measurements, taken typically between a celestial body (e.g. the Sun, the Moon, a planet, or a star) and the visible horizon. Celestial navigation can also take advantage of measurements between celestial bodies without reference to the Earth horizon, such as when the Moon and other selected bodies are used in the practice called "lunars" or lunar distance method, used for determining precise time when time is unknown. Celestial navigation by taking sights of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bowditch's American Practical Navigator
''The American Practical Navigator'' (colloquially often referred to as ''Bowditch''), originally written by Nathaniel Bowditch, is an encyclopedia of navigation. It serves as a valuable handbook on oceanography and meteorology, and contains useful tables and a maritime glossary. In 1867 the copyright and plates were bought by the Hydrographic Office of the United States Navy. As of 2019 it is still published by the U.S. Government and is available free online from the National Geospatial-Intelligence Agency (NGA), the modern successor agency to the 19th Century Hydrographic Office. The publication is considered one of America's nautical institutions. History The most popular navigational text of the late 18th century was ''The Practical Navigator'' by John Hamilton Moore of the Royal Navy, first published in 1772. To have exact tables to work from, Bowditch recomputed all of Moore's tables, and rearranged and expanded the work. He contacted the US publisher of the work, Edmu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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