Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. The field of navigation includes four general categories: land navigation, marine navigation , aeronautic navigation, and space navigation.
133-435: It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks. All navigational techniques involve locating the navigator's position compared to known locations or patterns. Navigation, in a broader sense, can refer to any skill or study that involves the determination of position and direction . In this sense, navigation includes orienteering and pedestrian navigation. In
266-408: A sea level rise of hundreds of meters following the last ice age. Both routes may have been taken, although the genetic evidences suggests a single founding population. The micro-satellite diversity and distributions specific to South American Indigenous peoples indicates that certain populations have been isolated since the initial colonization of the region. A second migration occurred after
399-713: A starship crew in science fiction , where they are sometimes called astrogators, a merger of the prefix "astro" and "navigator". According to a science fiction citations site for the Oxford English Dictionary , the earliest known use of the word is in David Lasser 's 1931 book The Conquest of Space . According to that site and also Brave New Words: The Oxford Dictionary of Science Fiction , it first appeared in science fiction in Stanley G. Weinbaum 's short story " The Planet of Doubt ", published in
532-454: A circle or arc of position. Circles, arcs, and hyperbolae of positions are often referred to as lines of position. If the navigator draws two lines of position, and they intersect he must be at that position. A fix is the intersection of two or more LOPs. If only one line of position is available, this may be evaluated against the dead reckoning position to establish an estimated position. Lines (or circles) of position can be derived from
665-406: A comprehensive passage plan depending on the size and type of vessel, each applicable according to the individual situation. A good passage plan will include a track line laid out upon the largest-scale charts available which cover the vessel's track. The navigator will draw and redraw the track line until it is safe, efficient, and in line with all applicable laws and regulations. When the track
798-468: A defined initial bearing. That is, upon taking an initial bearing, one proceeds along the same bearing, without changing the direction as measured relative to true or magnetic north. Most modern navigation relies primarily on positions determined electronically by receivers collecting information from satellites. Most other modern techniques rely on finding intersecting lines of position or LOP. A line of position can refer to two different things, either
931-547: A degree or so. Similar to latitude, the longitude of a place on Earth is the angular distance east or west of the prime meridian or Greenwich meridian . Longitude is usually expressed in degrees (marked with °) ranging from 0° at the Greenwich meridian to 180° east and west. Sydney , for example, has a longitude of about 151° east . New York City has a longitude of 74° west . For most of history, mariners struggled to determine longitude. Longitude can be calculated if
1064-573: A few hidden documents remain today, leaving modern historians with glimpses of ancient culture and knowledge. The first inhabitants migrated into the Americas from Asia. Habitation sites are known in Alaska and Yukon from at least 20,000 years ago, with suggested ages of up to 40,000 years. Beyond that, the specifics of the Paleo-Indian migration to and throughout the Americas, including
1197-495: A folio of over three thousand charts this can be a laborious and time-consuming task for the navigator. Various and diverse methods exist for the correction of electronic navigational charts. The term nautical publications is used in maritime circles to describe a set of publications, generally published by national governments, for use in safe navigation of ships, boats, and similar vessels. The nature of waterways described by any given nautical publication changes regularly, and
1330-427: A global system. Navigator A navigator is the person on board a ship or aircraft responsible for its navigation . The navigator's primary responsibility is to be aware of ship or aircraft position at all times. Responsibilities include planning the journey, advising the ship's captain or aircraft commander of estimated timing to destinations while en route, and ensuring hazards are avoided. The navigator
1463-404: A hundred years, from about 1767 until about 1850, mariners lacking a chronometer used the method of lunar distances to determine Greenwich time to find their longitude. A mariner with a chronometer could check its reading using a lunar determination of Greenwich time. In navigation, a rhumb line (or loxodrome) is a line crossing all meridians of longitude at the same angle, i.e. a path derived from
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#17327805512481596-625: A lesser extent, Dutch . The Americas are home to more than a billion inhabitants, two-thirds of whom reside in the United States , Brazil , and Mexico . It is home to eight megacities ( metropolitan areas with 10 million inhabitants or more): Greater Mexico City (21.2 million), São Paulo (21.2 million), New York City (19.7 million), Los Angeles (18.8 million), Buenos Aires (15.6 million), Rio de Janeiro (13.0 million), Bogotá (10.4 million), and Lima (10.1 million). The name "America"
1729-418: A line on a chart or a line between the observer and an object in real life. A bearing is a measure of the direction to an object. If the navigator measures the direction in real life, the angle can then be drawn on a nautical chart and the navigator will be somewhere on that bearing line on the chart. In addition to bearings, navigators also often measure distances to objects. On the chart, a distance produces
1862-709: A mariner navigating by use of an old or uncorrected publication is courting disaster. Every producer of nautical publications also provides a system to inform mariners of changes that affect the chart. In the United States, corrections and notifications of new editions are provided by various governmental agencies by way of Notice to Mariners , Local Notice to Mariners , Summary of Corrections , and Broadcast Notice to Mariners. Radio broadcasts give advance notice of urgent corrections. For ensuring that all publications are fully up-to-date, similar methods are employed as for nautical charts. Various and diverse methods exist for
1995-669: A maritime or flight region and adjacent coastal regions. Depending on the scale of the chart, it may show depths of water and heights of land, natural features of the seabed, details of the coastline, navigational hazards, locations of natural and man-made aids to navigation , information on tides and currents , local details of the Earth's magnetic field , restricted flying areas, and man-made structures such as harbors , buildings and bridges . Nautical charts are essential tools for marine navigation; many countries require vessels, especially commercial ships, to carry them. Nautical charting may take
2128-427: A million years, with the total spread of South American genera into North America far more limited in scope than the spread of North American genera into South America. There are 35 sovereign states in the Americas, as well as an autonomous country of Denmark , three overseas departments of France , three overseas collectivities of France, and one uninhabited territory of France, eight overseas territories of
2261-485: A number of islands. The gaps in the archipelago of Central America filled in with material eroded off North America and South America, plus new land created by continued volcanism. By three million years ago, the continents of North America and South America were linked by the Isthmus of Panama , thereby forming the single landmass of the Americas. The Great American Interchange resulted in many species being spread across
2394-449: A number of stars in succession to give a series of overlapping lines of position. Where they intersect is the celestial fix. The Moon and Sun may also be used. The Sun can also be used by itself to shoot a succession of lines of position (best done around local noon) to determine a position. In order to accurately measure longitude, the precise time of a sextant sighting (down to the second, if possible) must be recorded. Each second of error
2527-399: A particularly good navigation system for ships and aircraft that might be flying at a distance from land. RDFs works by rotating a directional antenna and listening for the direction in which the signal from a known station comes through most strongly. This sort of system was widely used in the 1930s and 1940s. RDF antennas are easy to spot on German World War II aircraft, as loops under
2660-559: A pre-voyage conference (USAF term is "mission briefing") in order to ensure that all members of the team share the same mental model of the entire trip. Passage planning procedures are specified in International Maritime Organization Resolutions, in the laws of IMO signatory countries (for example, Title 33 of the U.S. Code of Federal Regulations ), and a number of professional books and USN/USAF publications. There are some fifty elements of
2793-416: A radio time signal. Times and frequencies of radio time signals are listed in publications such as Radio Navigational Aids . The second critical component of celestial navigation is to measure the angle formed at the observer's eye between the celestial body and the sensible horizon. The sextant, an optical instrument, is used to perform this function. The sextant consists of two primary assemblies. The frame
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#17327805512482926-722: A series of rivers and streams that flow east with their terminus in the Atlantic Ocean, such as the Hudson River , Saint John River , and Savannah River . A similar instance arises with central Canadian rivers that drain into Hudson Bay ; the largest being the Churchill River . On the west coast of North America, the main rivers are the Colorado River , Columbia River , Yukon River , Fraser River , and Sacramento River . The Colorado River drains much of
3059-541: A shared population of flora and fauna around 2.5 million years ago, when continental drift brought the two continents into contact via the Isthmus of Panama . Initially, the exchange of biota was roughly equal, with North American genera migrating into South America in about the same proportions as South American genera migrated into North America. This exchange is known as the Great American Interchange . The exchange became lopsided after roughly
3192-410: A single object," "two or more bearings," "tangent bearings," and "two or more ranges." Radar can also be used with ECDIS as a means of position fixing with the radar image or distance/bearing overlaid onto an Electronic nautical chart . Parallel indexing is a technique defined by William Burger in the 1957 book The Radar Observer's Handbook . This technique involves creating a line on the screen that
3325-401: A sufficient depth of water below the hull as well as a consideration for squat . It may also involve navigating a ship within a river, canal or channel in close proximity to land. A military navigation team will nearly always consist of several people. A military navigator might have bearing takers stationed at the gyro repeaters on the bridge wings for taking simultaneous bearings, while
3458-644: A synonym). Latin America is typically contrasted with Anglo-America , where English, a Germanic language , is prevalent, and which comprises Canada (with the exception of Francophone Canada rooted in Latin Europe [France]—see Quebec and Acadia ) and the United States. Both countries are located in North America, with cultures deriving predominantly from British and other Germanic roots. The transatlantic slave trade brought millions of Africans to
3591-410: A variety of sources: There are some methods seldom used today such as "dipping a light" to calculate the geographic range from observer to lighthouse. Methods of navigation have changed through history. Each new method has enhanced the mariner's ability to complete his voyage. One of the most important judgments the navigator must make is the best method to use. Some types of navigation are depicted in
3724-453: A wide variety of indigenous religions, many of which can be categorized as animistic ; new age religions and many African and African-derived religions. Syncretic faiths can also be found throughout the Americas. Various languages are spoken in the Americas. Some are of European origin, others are spoken by indigenous peoples or are the mixture of various languages like the different creoles. The most widely spoken first language in
3857-451: Is Pulsar navigation , which compares the X-ray bursts from a collection of known pulsars in order to determine the position of a spacecraft. This method has been tested by multiple space agencies, such as NASA and ESA . A radio direction finder or RDF is a device for finding the direction to a radio source. Due to radio's ability to travel very long distances "over the horizon", it makes
3990-432: Is a quartz crystal oscillator. The quartz crystal is temperature compensated and is hermetically sealed in an evacuated envelope. A calibrated adjustment capability is provided to adjust for the aging of the crystal. The chronometer is designed to operate for a minimum of one year on a single set of batteries. Observations may be timed and ship's clocks set with a comparing watch, which is set to chronometer time and taken to
4123-425: Is a rigid triangular structure with a pivot at the top and a graduated segment of a circle, referred to as the "arc", at the bottom. The second component is the index arm, which is attached to the pivot at the top of the frame. At the bottom is an endless vernier which clamps into teeth on the bottom of the "arc". The optical system consists of two mirrors and, generally, a low power telescope. One mirror, referred to as
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4256-1052: Is considered to be the V-2 guidance system deployed by the Germans in 1942. However, inertial sensors are traced to the early 19th century. The advantages INSs led their use in aircraft, missiles, surface ships and submarines. For example, the U.S. Navy developed the Ships Inertial Navigation System (SINS) during the Polaris missile program to ensure a reliable and accurate navigation system to initial its missile guidance systems. Inertial navigation systems were in wide use until satellite navigation systems (GPS) became available. INSs are still in common use on submarines (since GPS reception or other fix sources are not possible while submerged) and long-range missiles. Not to be confused with satellite navigation, which depends upon satellites to function, space navigation refers to
4389-440: Is equivalent to 15 seconds of longitude error, which at the equator is a position error of .25 of a nautical mile, about the accuracy limit of manual celestial navigation. The spring-driven marine chronometer is a precision timepiece used aboard ship to provide accurate time for celestial observations. A chronometer differs from a spring-driven watch principally in that it contains a variable lever device to maintain even pressure on
4522-735: Is finished, it is becoming common practice to also enter it into electronic navigation tools such as an Electronic Chart Display and Information System , a chartplotter , or a GPS unit. Once the voyage has begun the progress of the vessel along its planned route must be monitored. This requires that the ship's position be determined, using standard methods including dead reckoning , radar fixing, celestial navigation , pilotage , and electronic navigation , to include usage of GPS and navigation computer equipment. Passage planning software, tide and tidal current predictors, celestial navigational calculators, consumables estimators for fuel, oil, water, and stores, and other useful applications. The navigator
4655-470: Is generally quite flat. Similarly, the north-east of South America is covered by the flat Amazon basin . The Brazilian Highlands on the east coast are fairly smooth but show some variations in landform, while farther south the Gran Chaco and Pampas are broad lowlands . The climate of the Americas varies significantly from region to region. Tropical rainforest climate occurs in the latitudes of
4788-419: Is in charge of maintaining the aircraft or ship's nautical charts , nautical publications , and navigational equipment, and they generally have responsibility for meteorological equipment and communications. With the advent of satellite navigation , the effort required to accurately determine one's position has decreased by orders of magnitude, so the entire field has experienced a revolutionary transition since
4921-478: Is not affected by adverse weather conditions and it cannot be detected or jammed. Its disadvantage is that since the current position is calculated solely from previous positions and motion sensors, its errors are cumulative, increasing at a rate roughly proportional to the time since the initial position was input. Inertial navigation systems must therefore be frequently corrected with a location 'fix' from some other type of navigation system. The first inertial system
5054-558: Is parallel to the ship's course, but offset to the left or right by some distance. This parallel line allows the navigator to maintain a given distance away from hazards . The line on the radar screen is set to a specific distance and angle, then the ship's position relative to the parallel line is observed. This can provide an immediate reference to the navigator as to whether the ship is on or off its intended course for navigation. Other techniques that are less used in general navigation have been developed for special situations. One, known as
5187-453: Is particularly useful due to their high power and location near major cities. Decca , OMEGA , and LORAN-C are three similar hyperbolic navigation systems. Decca was a hyperbolic low frequency radio navigation system (also known as multilateration ) that was first deployed during World War II when the Allied forces needed a system which could be used to achieve accurate landings. As
5320-457: Is reasonable for the navigator to simply monitor the progress of the ship along the chosen track, visually ensuring that the ship is proceeding as desired, checking the compass, sounder and other indicators only occasionally. If a pilot is aboard, as is often the case in the most restricted of waters, his judgement can generally be relied upon, further easing the workload. But should the ECDIS fail,
5453-415: Is responsible for the maintenance of the ship's navigational equipment. U.S. Air Force navigators are responsible for troubleshooting problems of the navigation equipment while airborne, but the ground Maintenance personnel are ultimately responsible for the repair and upkeep of that aircraft's navigation system. Boats and ships can use several Global Navigation Satellite Systems (GNSS) to navigate all of
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5586-691: Is that of the Mississippi , covering the second largest watershed on the planet. The Mississippi-Missouri river system drains most of 31 states of the United States, most of the Great Plains , and large areas between the Rocky and Appalachian mountains. This river is the fourth longest in the world and tenth most powerful in the world . In North America, to the east of the Appalachian Mountains , there are no major rivers but rather
5719-538: Is the 2nd largest continent right after Asia, and is the 3rd largest continent by population. The Americas make up most of the land in Earth 's Western Hemisphere and comprise the New World . Along with their associated islands , the Americas cover 8% of Earth's total surface area and 28.4% of its land area. The topography is dominated by the American Cordillera , a long chain of mountains that runs
5852-399: Is with a "chart and publication correction record card" system. Using this system, the navigator does not immediately update every chart in the portfolio when a new Notice to Mariners arrives, instead creating a card for every chart and noting the correction on this card. When the time comes to use the chart, the navigator pulls the chart and chart's card, and makes the indicated corrections on
5985-533: The Amazon , American cloud forests , southeastern Florida and Darién Gap . In the Rocky Mountains and Andes , dry and continental climates are observed. Often the higher altitudes of these mountains are snow-capped. Southeastern North America is well known for its occurrence of tornadoes and hurricanes , of which the vast majority of tornadoes occur in the United States' Tornado Alley , as well as in
6118-715: The Arctic small tool tradition , a broad cultural entity that developed along the Alaska Peninsula , around Bristol Bay , and on the eastern shores of the Bering Strait c. 2500 BCE moved into North America. The Arctic small tool tradition, a Paleo-Eskimo culture branched off into two cultural variants, including the Pre-Dorset , and the Independence traditions of Greenland. The descendants of
6251-708: The Boothia Peninsula in northern Canada and Cape Froward in Chilean Patagonia , is roughly 14,000 km (8,700 mi). The mainland's most westerly point is the end of the Seward Peninsula in Alaska; Attu Island , further off the Alaskan coast to the west, is considered the westernmost point of the Americas. Ponta do Seixas in northeastern Brazil forms the easternmost extremity of
6384-495: The Latin version of Italian explorer Amerigo Vespucci 's first name. The feminine form America was originally used to refer to the newly discovered continent, which is why it was accorded with the feminine names of the other continents: Asia , Africa , and Europa . Since the 1950s, however, North America and South America have generally been considered by English speakers as separate continents, and taken together are called
6517-574: The Quaternary glaciation . These people are believed to have followed herds of now-extinct pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran ice sheets. Another route proposed is that, either on foot or using primitive boats , they migrated down the Pacific coast to South America. Evidence of the latter would since have been covered by
6650-708: The Southern Rockies and parts of the Basin and Range Province . The river flows approximately 1,450 miles (2,330 km) into the Gulf of California , during which over time it has carved out natural phenomena such as the Grand Canyon and created phenomena such as the Salton Sea . The Columbia is a large river, 1,243 miles (2,000 km) long, in central western North America and is the most powerful river on
6783-853: The Spanish monarchs funded Christopher Columbus 's expedition to sail west to reach the Indies by crossing the Atlantic, which resulted in the Discovery of the Americas . In 1498, a Portuguese expedition commanded by Vasco da Gama reached India by sailing around Africa, opening up direct trade with Asia . Soon, the Portuguese sailed further eastward, to the Spice Islands in 1512, landing in China one year later. The first circumnavigation of
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#17327805512486916-606: The United Kingdom , three constituent countries of the Netherlands , three public bodies of the Netherlands, two unincorporated territories of the United States , and one uninhabited territory of the United States. In 2021 the total population of the Americas was about 1.03 billion people, divided as follows: There are three urban centers that each hold titles for being the largest population area based on
7049-490: The United States in cooperation with six partner nations. OMEGA was developed by the United States Navy for military aviation users. It was approved for development in 1968 and promised a true worldwide oceanic coverage capability with only eight transmitters and the ability to achieve a four-mile (6 km) accuracy when fixing a position. Initially, the system was to be used for navigating nuclear bombers across
7182-477: The enslavement of large numbers of the indigenous population of America. Diseases introduced from Europe and West Africa devastated the indigenous peoples , and the European powers colonized the Americas . Mass emigration from Europe , including large numbers of indentured servants , and importation of African slaves largely replaced the indigenous peoples in much of the Americas. Decolonization of
7315-520: The "contour method," involves marking a transparent plastic template on the radar screen and moving it to the chart to fix a position. Another special technique, known as the Franklin Continuous Radar Plot Technique, involves drawing the path a radar object should follow on the radar display if the ship stays on its planned course. During the transit, the navigator can check that the ship is on track by checking that
7448-400: The "index mirror" is fixed to the top of the index arm, over the pivot. As the index arm is moved, this mirror rotates, and the graduated scale on the arc indicates the measured angle ("altitude"). The second mirror, referred to as the "horizon glass", is fixed to the front of the frame. One half of the horizon glass is silvered and the other half is clear. Light from the celestial body strikes
7581-454: The 1530s, from Latin navigationem (nom. navigatio ), from navigatus , pp. of navigare "to sail, sail over, go by sea, steer a ship," from navis "ship" and the root of agere "to drive". Roughly, the latitude of a place on Earth is its angular distance north or south of the equator . Latitude is usually expressed in degrees (marked with °) ranging from 0° at the Equator to 90° at
7714-448: The 1990s with traditional navigation tasks, like performing celestial navigation , being used less frequently. Using multiple independent position fix methods without solely relying on electronic systems subject to failure helps the navigator detect errors. Professional mariners are still proficient in traditional piloting and celestial navigation. Shipborne navigators in the U.S. Navy are normally surface warfare officer qualified with
7847-957: The American continents, spanning the time of the original settlement in the Upper Paleolithic to European colonization during the Early Modern period . The term Pre-Columbian is used especially often in the context of the great indigenous civilizations of the Americas , such as those of Mesoamerica ( Olmec , Toltec , Teotihuacano , Zapotec , Mixtec , Aztec , Maya ) and the Andean civilizations ( Inca , Moche , Chavín , Muisca , Cañari ). Many pre-Columbian civilizations established characteristics and hallmarks which included permanent or urban settlements, agriculture, civic and monumental architecture, and complex societal hierarchies . Some of these civilizations had long faded by
7980-610: The Americas began with the American Revolution in the 1770s and largely ended with the Spanish–American War in the late 1890s. Currently, almost all of the population of the Americas resides in independent countries; however, the legacy of the colonization and settlement by Europeans is that the Americas share many common cultural traits, most notably Christianity and the use of West European languages: primarily Spanish , English , Portuguese , French , and, to
8113-582: The Americas from Asia between 20,000 and 16,000 years ago. A second migration of Na-Dene speakers followed later from Asia. The subsequent migration of the Inuit into the neoarctic c. 3500 BCE completed what is generally regarded as the settlement by the Indigenous peoples of the Americas . The first known European settlement in the Americas was by the Norse explorer Leif Erikson . However,
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#17327805512488246-495: The Americas , or more rarely America . When conceived as a unitary continent, the form is generally the continent of America in the singular. However, without a clarifying context, singular America in English commonly refers to the United States of America . The pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on
8379-476: The Americas began with the first voyage of Christopher Columbus in 1492. The first Spanish settlement in the Americas was La Isabela in northern Hispaniola . This town was abandoned shortly after in favor of Santo Domingo de Guzmán , founded in 1496, the oldest American city of European foundation. This was the base from which the Spanish monarchy administered its new colonies and their expansion. Santo Domingo
8512-534: The Americas is Spanish , followed by English and Portuguese . The dominant language of Latin America is Spanish, though the most populous nation in Latin America, Brazil , speaks Portuguese . Small enclaves of French -, Dutch - and English-speaking regions also exist in Latin America, notably in French Guiana , Suriname , and Belize and Guyana respectively. Haitian Creole is dominant in
8645-597: The Americas is made up of the descendants of four large ethnic groups and their combinations. The majority of the population lives in Latin America , named for its predominant cultures, rooted in Latin Europe (including the two dominant languages, Spanish and Portuguese , both Romance languages ), more specifically in the Iberian nations of Portugal and Spain (hence the use of the term Ibero-America as
8778-489: The Americas, such as the cougar , porcupine , opossums , armadillos , and hummingbirds . The geography of the western Americas is dominated by the American Cordillera , with the Andes running along the west coast of South America and the Rocky Mountains and other North American Cordillera ranges running along the western side of North America. The 2,300-kilometer-long (1,400 mi) Appalachian Mountains run along
8911-506: The Americas. Migration continued as people moved to the Americas fleeing religious persecution or seeking economic opportunities. Millions of individuals were forcibly transported to the Americas as slaves , prisoners or indentured servants . Decolonization of the Americas began with the American Revolution and the Haitian Revolution in the late 1700s. This was followed by numerous Latin American wars of independence in
9044-603: The Atlantic Ocean. The Mackenzie River is the largest in Canada and drains 1,805,200 square kilometers (697,000 sq mi). The largest river basin in South America is that of the Amazon , which has the highest volume flow of any river on Earth. The second largest watershed of South America is that of the Paraná River , which covers about 2.5 million km . North America and South America began to develop
9177-731: The Caribbean began to achieve peaceful independence well after World War II . Jamaica and Trinidad and Tobago became independent in 1962, and Guyana and Barbados both achieved independence in 1966. In the 1970s, the Bahamas , Grenada , Dominica , St. Lucia , and St. Vincent and the Grenadines all became independent of the United Kingdom, and Suriname became independent of the Netherlands. Belize , Antigua and Barbuda , and Saint Kitts and Nevis achieved independence from
9310-487: The European medieval period, navigation was considered part of the set of seven mechanical arts , none of which were used for long voyages across open ocean. Polynesian navigation is probably the earliest form of open-ocean navigation; it was based on memory and observation recorded on scientific instruments like the Marshall Islands Stick Charts of Ocean Swells . Early Pacific Polynesians used
9443-534: The Hudson River Valley, and what later became New Jersey. The spread of new diseases brought by Europeans and African slaves killed many of the inhabitants of North America and South America, with a general population crash of Native Americans occurring in the mid-16th century, often well ahead of European contact. One of the most devastating diseases was smallpox . European immigrants were often part of state-sponsored attempts to found colonies in
9576-602: The Norse colonies and Europe was maintained, as James Watson Curran states: From 985 to 1410, Greenland was in touch with the world. Then silence. In 1492 the Vatican noted that no news of that country "at the end of the world" had been received for 80 years, and the bishopric of the colony was offered to a certain ecclesiastic if he would go and "restore Christianity" there. He didn't go. Although there had been previous trans-oceanic contact , large-scale European colonization of
9709-552: The North Pole to Russia. Later, it was found useful for submarines. Due to the success of the Global Positioning System the use of Omega declined during the 1990s, to a point where the cost of operating Omega could no longer be justified. Omega was terminated on September 30, 1997, and all stations ceased operation. LORAN is a terrestrial navigation system using low frequency radio transmitters that use
9842-649: The North and South poles. The latitude of the North Pole is 90° N, and the latitude of the South Pole is 90° S. Mariners calculated latitude in the Northern Hemisphere by sighting the pole star ( Polaris ) with a sextant and using sight reduction tables to correct for height of eye and atmospheric refraction. The height of Polaris in degrees above the horizon is the latitude of the observer, within
9975-458: The October 1935 issue of Astounding Stories . The title character of Robert A. Heinlein 's 1953 novel Starman Jones is an astrogator. Americas The Americas , sometimes collectively called America , known initially as India Nova , are a landmass comprising the totality of North America and South America . When viewed as a single continent, the Americas or America
10108-635: The Philippines, trying to find a maritime path back to the Americas , but was unsuccessful. The eastward route across the Pacific, also known as the tornaviaje (return trip) was only discovered forty years later, when Spanish cosmographer Andrés de Urdaneta sailed from the Philippines, north to parallel 39°, and hit the eastward Kuroshio Current which took its galleon across the Pacific. He arrived in Acapulco on October 8, 1565. The term stems from
10241-778: The Pre-Dorset cultural group, the Dorset culture was displaced by the final migrants from the Bering sea coast line, the Thule people (the ancestors of modern Inuit ), by 1000 CE . Around the same time as the Inuit migrated into Greenland, Viking settlers began arriving in Greenland in 982 and Vinland shortly thereafter, establishing a settlement at L'Anse aux Meadows , near the northernmost tip of Newfoundland . Contact between
10374-548: The United Kingdom in the 1980s. The Americas make up most of the land in Earth's Western Hemisphere . The northernmost point of the Americas is Kaffeklubben Island , which is the most northerly point of land on Earth. The southernmost point is the islands of Southern Thule , although they are sometimes considered part of Antarctica . The mainland of the Americas is the world's longest north-to-south landmass. The distance between its two polar extremities, Murchison Promontory on
10507-635: The United Kingdom, starting with the Balfour Declaration of 1926 , Statute of Westminster 1931 , and ending with the patriation of the Canadian Constitution in 1982. The Dominion of Newfoundland similarly achieved independence under the Balfour Declaration and Statute of Westminster, but relinquished self-rule in 1934. It was subsequently confederated with Canada in 1949. The remaining European colonies in
10640-616: The United States, and more specifically in the US state of Colorado . The highest peaks of the Americas are located in the Andes , with Aconcagua of Argentina being the highest; in North America Denali (Mount McKinley) in the US state of Alaska is the tallest. Between its coastal mountain ranges, North America has vast flat areas. The Interior Plains spread over much of the continent, with low relief. The Canadian Shield covers almost 5 million km of North America and
10773-941: The West Coast of the Americas. In the far northwest of North America, the Yukon drains much of the Alaskan peninsula and flows 1,980 miles (3,190 km) from parts of Yukon and the Northwest Territory to the Pacific. Draining to the Arctic Ocean of Canada, the Mackenzie River drains waters from the Arctic Great Lakes of Arctic Canada, as opposed to the Saint-Lawrence River that drains the Great Lakes of Southern Canada into
10906-491: The bridge wing for recording sight times. In practice, a wrist watch coordinated to the nearest second with the chronometer will be adequate. A stop watch, either spring wound or digital, may also be used for celestial observations. In this case, the watch is started at a known GMT by chronometer, and the elapsed time of each sight added to this to obtain GMT of the sight. All chronometers and watches should be checked regularly with
11039-526: The chart. This system ensures that every chart is properly corrected prior to use. British merchant vessels receive weekly Notices to Mariners issued by the Admiralty . When corrections are received all charts are corrected in the ship's folio and recorded in NP133A (Admiralty Chart Correction Log and Folio Index). This system ensures that all charts are corrected and up to date. In a deep-sea vessel with
11172-419: The civilian navigator on a merchant ship or leisure craft must often take and plot their position themselves, typically with the aid of electronic position fixing. While the military navigator will have a bearing book and someone to record entries for each fix, the civilian navigator will simply pilot the bearings on the chart as they are taken and not record them at all. If the ship is equipped with an ECDIS , it
11305-481: The colonization never became permanent and was later abandoned. The Spanish voyages of Christopher Columbus from 1492 to 1504 resulted in permanent contact with European (and subsequently, other Old World ) powers, which eventually led to the Columbian exchange and inaugurated a period of exploration , conquest, and colonization whose effects and consequences persist to the present. The Spanish presence involved
11438-443: The correction of electronic nautical publications. The navigator focuses on creating the ship's passage plans (or "mission plans" for USAF purposes). A mission or passage plan can be summarized as a comprehensive, step by step description of how the voyage is to proceed from berth to berth, including unberthing, departure, the en-route portion of a voyage, approach, and mooring/arrival at the destination. Before each voyage begins,
11571-549: The dates and routes traveled, are subject to ongoing research and discussion. Widespread habitation of the Americas occurred after the Late Glacial Maximum , from 16,000 to 13,000 years ago. The traditional theory has been that these early migrants moved into the Beringia land bridge between eastern Siberia and present-day Alaska around 40,000–17,000 years ago, when sea levels were significantly lowered during
11704-577: The dedicated Navigator's position was discontinued and its function was assumed by dual-licensed Pilot-Navigators, and still later by the aircraft's primary pilots (Captain and FO), resulting in a continued downsizing in the number of aircrew positions on commercial flights. Modern electronic navigation systems made the civil aviation navigators redundant by the early 1980s. In military aviation , navigators are still actively trained and licensed in some present day air forces , as electronic navigation aids cannot be assumed to be operational during wartime . In
11837-685: The early 1800s. Between 1811 and 1825, Paraguay , Argentina , Chile , Gran Colombia , the United Provinces of Central America , Mexico , Brazil , Peru , and Bolivia gained independence from Spain and Portugal in armed revolutions. After the Dominican Republic won independence from Haiti , it was re-annexed by Spain in 1861, but reclaimed its independence in 1865 at the conclusion of the Dominican Restoration War . The last violent episode of decolonization
11970-602: The earth was completed in 1522 with the Magellan-Elcano expedition , a Spanish voyage of discovery led by Portuguese explorer Ferdinand Magellan and completed by Spanish navigator Juan Sebastián Elcano after the former's death in the Philippines in 1521. The fleet of seven ships sailed from Sanlúcar de Barrameda in Southern Spain in 1519, crossed the Atlantic Ocean and after several stopovers rounded
12103-604: The east coast of North America from Alabama to Newfoundland . North of the Appalachians, the Arctic Cordillera runs along the eastern coast of Canada. The largest mountain ranges are the Andes and Rocky Mountains . The Sierra Nevada and the Cascade Range reach similar altitudes as the Rocky Mountains , but are significantly smaller. In North America, the greatest number of fourteeners are in
12236-462: The exception of naval aviators and naval flight officers assigned to ship's navigator billets aboard aircraft carriers and large deck amphibious assault ships and who have been qualified at a level equal to surface warfare officers. U.S. Coast Guard officers that are shipboard navigators are normally cutter qualified at a level analogous to the USN officers previously mentioned. Quartermasters are
12369-645: The first half of the 16th century, Spanish colonists conducted raids throughout the Caribbean Basin , bringing captives from Central America, northern South America, and Florida back to Hispaniola and other Spanish settlements. France, led by Jacques Cartier and Giovanni da Verrazzano , focused primarily on North America. English explorations of the Americas were led by Giovanni Caboto and Sir Walter Raleigh . The Dutch in New Netherland confined their operations to Manhattan Island, Long Island,
12502-735: The form of charts printed on paper or computerised electronic navigational charts . The nature of a waterway depicted by a chart changes regularly, and a mariner navigating on an old or uncorrected chart is courting disaster. Every producer of navigational charts also provides a system to inform mariners and aviators of changes that affect the chart. In the United States, chart corrections and notifications of new editions are provided by various governmental agencies by way of Notices to Airmen (NOTAMs), Notice to Mariners , Local Notice to Mariners , Summary of Corrections , and Broadcast Notice to Mariners. Radio broadcasts give advance notice of urgent corrections. A convenient way to keep track of corrections
12635-670: The ground with a fixed position can also be used to calculate the precise time as a reference for scientific experiments. As of October 2011, only the United States NAVSTAR Global Positioning System (GPS) and the Russian GLONASS are fully globally operational GNSSs. The European Union 's Galileo positioning system is a next generation GNSS in the final deployment phase, and became operational in 2016. China has indicated it may expand its regional Beidou navigation system into
12768-425: The horizon or more preferably a star, each time the sextant is used. The practice of taking celestial observations from the deck of a rolling ship, often through cloud cover and with a hazy horizon, is by far the most challenging part of celestial navigation. Inertial navigation system (INS) is a dead reckoning type of navigation system that computes its position based on motion sensors. Before actually navigating,
12901-480: The index mirror and is reflected to the silvered portion of the horizon glass, then back to the observer's eye through the telescope. The observer manipulates the index arm so the reflected image of the body in the horizon glass is just resting on the visual horizon, seen through the clear side of the horizon glass. Adjustment of the sextant consists of checking and aligning all the optical elements to eliminate "index correction". Index correction should be checked, using
13034-617: The initial latitude and longitude and the INS's physical orientation relative to the Earth (e.g., north and level) are established. After alignment, an INS receives impulses from motion detectors that measure (a) the acceleration along three axes (accelerometers), and (b) rate of rotation about three orthogonal axes (gyroscopes). These enable an INS to continually and accurately calculate its current latitude and longitude (and often velocity). Advantages over other navigation systems are that, once aligned, an INS does not require outside information. An INS
13167-525: The initial peopling of the Americas; Na Dene speakers found predominantly in North American groups at varying genetic rates with the highest frequency found among the Athabaskans at 42% derive from this second wave. Linguists and biologists have reached a similar conclusion based on analysis of Amerindian language groups and ABO blood group system distributions. Then the people of
13300-549: The length of the west coast. The flatter eastern side of the Americas is dominated by large river basins, such as the Amazon , St. Lawrence River – Great Lakes , Mississippi , and La Plata basins. Since the Americas extend 14,000 km (8,700 mi) from north to south, the climate and ecology vary widely, from the arctic tundra of Northern Canada , Greenland , and Alaska , to the tropical rainforests in Central America and South America. Humans first settled
13433-604: The mainland, while Nordostrundingen , in Greenland, is the most easterly point of the continental shelf. South America broke off from the west of the supercontinent Gondwana around 135 million years ago, forming its own continent. Around 15 million years ago, the collision of the Caribbean Plate and the Pacific Plate resulted in the emergence of a series of volcanoes along the border that created
13566-445: The mainspring, and a special balance designed to compensate for temperature variations. A spring-driven chronometer is set approximately to Greenwich mean time (GMT) and is not reset until the instrument is overhauled and cleaned, usually at three-year intervals. The difference between GMT and chronometer time is carefully determined and applied as a correction to all chronometer readings. Spring-driven chronometers must be wound at about
13699-406: The mid-1960s. USAF navigators/combat systems officers and USN/USMC naval flight officers must be basic mission qualified in their aircraft, or fly with an instructor navigator or instructor NFO to provide the necessary training for their duties. A naval ship's navigator is responsible for buying and maintaining its nautical charts. A nautical chart, or simply "chart", is a graphic representation of
13832-666: The motion of stars, weather, the position of certain wildlife species, or the size of waves to find the path from one island to another. Maritime navigation using scientific instruments such as the mariner's astrolabe first occurred in the Mediterranean during the Middle Ages. Although land astrolabes were invented in the Hellenistic period and existed in classical antiquity and the Islamic Golden Age ,
13965-544: The navigation of spacecraft themselves. This has historically been achieved (during the Apollo program ) via a navigational computer , an Inertial navigation system, and via celestial inputs entered by astronauts which were recorded by sextant and telescope. Space rated navigational computers, like those found on Apollo and later missions, are designed to be hardened against possible data corruption from radiation. Another possibility that has been explored for deep space navigation
14098-402: The navigator should develop a detailed mental model of how the entire voyage will proceed. In the aviation community, this is known as "chair flying". This mental model includes charting courses and forecasting weather, tides, and currents. It includes updating and checking aeronautical charts , nautical publications , which could include Sailing Directions and Coast Pilots , and projecting
14231-460: The navigator will have to rely on his skill in the manual and time-tested procedures. Celestial navigation systems are based on observation of the positions of the Sun , Moon , planets and navigational stars . Such systems are in use as well for terrestrial navigating as for interstellar navigating. By knowing which point on the rotating Earth a celestial object is above and measuring its height above
14364-884: The navigator's enlisted assistants and perform most of the technical navigation duties. Aboard ships in the Merchant Marine and Merchant Navy , the second mate is generally the (senior) navigator. Navigators are sometimes also called 'air navigators' or 'flight navigators'. In civil aviation this was a position on older aircraft, typically between the late-1910s and the 1970s, where separate crew members (sometimes two navigation crew members) were often responsible for an aircraft's flight navigation, including its dead reckoning and celestial navigation , especially when flown over oceans or other large featureless areas where radio navigation aids were not originally available. As sophisticated electronic air navigation aids and universal space-based GPS navigation systems came online,
14497-405: The observer's horizon, the navigator can determine his distance from that subpoint. A nautical almanac and a marine chronometer are used to compute the subpoint on Earth a celestial body is over, and a sextant is used to measure the body's angular height above the horizon. That height can then be used to compute distance from the subpoint to create a circular line of position. A navigator shoots
14630-502: The oldest record of a sea astrolabe is that of Spanish astronomer Ramon Llull dating from 1295. The perfecting of this navigation instrument is attributed to Portuguese navigators during early Portuguese discoveries in the Age of Discovery . The earliest known description of how to make and use a sea astrolabe comes from Spanish cosmographer Martín Cortés de Albacar 's Arte de Navegar ( The Art of Navigation ) published in 1551, based on
14763-400: The pip lies on the drawn line. Global Navigation Satellite System or GNSS is the term for satellite navigation systems that provide positioning with global coverage. A GNSS allow small electronic receivers to determine their location ( longitude , latitude , and altitude ) within a few meters using time signals transmitted along a line of sight by radio from satellites . Receivers on
14896-408: The precise time of a sighting is known. Lacking that, one can use a sextant to take a lunar distance (also called the lunar observation , or "lunar" for short) that, with a nautical almanac , can be used to calculate the time at zero longitude (see Greenwich Mean Time ). Reliable marine chronometers were unavailable until the late 18th century and not affordable until the 19th century. For about
15029-626: The principle of the archipendulum used in constructing the Egyptian pyramids . Open-seas navigation using the astrolabe and the compass started during the Age of Discovery in the 15th century. The Portuguese began systematically exploring the Atlantic coast of Africa from 1418, under the sponsorship of Prince Henry . In 1488 Bartolomeu Dias reached the Indian Ocean by this route. In 1492
15162-426: The radar scanner. When a vessel (ship or boat) is within radar range of land or fixed objects (such as special radar aids to navigation and navigation marks) the navigator can take distances and angular bearings to charted objects and use these to establish arcs of position and lines of position on a chart. A fix consisting of only radar information is called a radar fix. Types of radar fixes include "range and bearing to
15295-517: The rear section of the fuselage, whereas most US aircraft enclosed the antenna in a small teardrop-shaped fairing. In navigational applications, RDF signals are provided in the form of radio beacons , the radio version of a lighthouse . The signal is typically a simple AM broadcast of a morse code series of letters, which the RDF can tune in to see if the beacon is "on the air". Most modern detectors can also tune in any commercial radio stations, which
15428-409: The same frequency range, called CHAYKA . LORAN use is in steep decline, with GPS being the primary replacement. However, there are attempts to enhance and re-popularize LORAN. LORAN signals are less susceptible to interference and can penetrate better into foliage and buildings than GPS signals. Radar is an effective aid to navigation because it provides ranges and bearings to objects within range of
15561-407: The same time each day. Quartz crystal marine chronometers have replaced spring-driven chronometers aboard many ships because of their greater accuracy. They are maintained on GMT directly from radio time signals. This eliminates chronometer error and watch error corrections. Should the second hand be in error by a readable amount, it can be reset electrically. The basic element for time generation
15694-443: The southerly Dixie Alley in the North American late-winter and early spring seasons. Often parts of the Caribbean are exposed to the violent effects of hurricanes. These weather systems are formed by the collision of dry, cool air from Canada and wet, warm air from the Atlantic. With coastal mountains and interior plains, the Americas have several large river basins that drain the continents. The largest river basin in North America
15827-609: The southern tip of South America . Some ships were lost, but the remaining fleet continued across the Pacific making a number of discoveries including Guam and the Philippines. By then, only two galleons were left from the original seven. The Victoria led by Elcano sailed across the Indian Ocean and north along the coast of Africa, to finally arrive in Spain in 1522, three years after its departure. The Trinidad sailed east from
15960-803: The table. The practice of navigation usually involves a combination of these different methods. By mental navigation checks, a pilot or a navigator estimates tracks, distances, and altitudes which will then help the pilot avoid gross navigation errors. Piloting (also called pilotage) involves navigating an aircraft by visual reference to landmarks, or a water vessel in restricted waters and fixing its position as precisely as possible at frequent intervals. More so than in other phases of navigation, proper preparation and attention to detail are important. Procedures vary from vessel to vessel, and between military, commercial, and private vessels. As pilotage takes place in shallow waters , it typically involves following courses to ensure sufficient under keel clearance , ensuring
16093-473: The territories of the Americas under the colonial rule of European powers. In South America, Portugal played a significant role in the trafficking of enslaved Africans, with estimates suggesting that around 40% of all Africans forcibly brought to the Americas were taken to Brazil alone, to work primarily in sugar cane plantations, mining, and agricultural endeavors. In North America, the British Empire
16226-475: The three main demographic concepts: In accordance with these definitions, the three largest population centers in the Americas are: Mexico City , anchor to the largest metropolitan area in the Americas; New York City, anchor to the largest urban area in the Americas; and São Paulo, the largest city proper in the Americas. All three cities maintain Alpha classification and large scale influence. The population of
16359-462: The time interval between radio signals received from three or more stations to determine the position of a ship or aircraft. The current version of LORAN in common use is LORAN-C, which operates in the low frequency portion of the EM spectrum from 90 to 110 kHz . Many nations are users of the system, including the United States , Japan , and several European countries. Russia uses a nearly exact system in
16492-533: The time of the first permanent European arrivals ( c. late 15th –early 16th centuries), and are known only through archeological investigations. Others were contemporary with this period, and are also known from historical accounts of the time. A few, such as the Maya, had their own written records. However, most Europeans of the time viewed such texts as pagan, and much was destroyed in Christian pyres. Only
16625-413: The various future events including landfalls, narrow passages, and course changes that will transpire during the voyage. This mental model becomes the standard by which the navigator will measure progress toward the goal of a safe and efficient voyage, and it is manifested in a written passage plan. When working in a team environment, the passage/mission plan should be communicated to the navigation team in
16758-562: The world's air forces, modern navigators are frequently tasked with weapons and defensive systems operations, along with co-pilot duties such as flight planning and fuel management, depending on the type, model and series of aircraft. In the U.S. Air Force , the aeronautical rating of navigator has been augmented by addition of the combat systems officer , while in the U.S. Navy and U.S. Marine Corps , those officers formerly called navigators, tactical systems officers, or naval aviation observers have been known as naval flight officers since
16891-510: The world's lakes, seas and oceans. Maritime GNSS units include functions useful on water, such as "man overboard" (MOB) functions that allow instantly marking the location where a person has fallen overboard, which simplifies rescue efforts. GNSS may be connected to the ships self-steering gear and Chartplotters using the NMEA 0183 interface, and GNSS can also improve the security of shipping traffic by enabling AIS . Navigators are often part of
17024-566: Was first recorded in 1507. A two-dimensional globe created by Martin Waldseemüller was the earliest recorded use of the term. The name was also used (together with the related term Amerigen ) in the Cosmographiae Introductio , apparently written by Matthias Ringmann , in reference to South America. It was applied to both North and South America by Gerardus Mercator in 1538. "America" derives from Americus ,
17157-440: Was heavily involved in the transatlantic slave trade, with the establishment of colonies such as Virginia, where enslaved Africans were primarily used as labor in tobacco plantations and later in other agricultural and domestic sectors. This system perpetuated for centuries, shaping the socio-economic landscape of all nations of the hemisphere. After the Haitian Revolution led by Jean-Jacques Dessalines , which started in 1791 and
17290-570: Was subject to frequent raids by English and French pirates . On the continent, Panama City on the Pacific coast of Central America, founded on August 15, 1519, played an important role, being the base for the Spanish conquest of South America. Conquistador Lucas Vázquez de Ayllón established San Miguel de Guadalupe , the first European settlement in what is now the United States , on the Pee Dee River in South Carolina . During
17423-585: Was the Cuban War of Independence which became the Spanish–American War , which resulted in the independence of Cuba in 1898, and the transfer of sovereignty over Puerto Rico from Spain to the United States. Peaceful decolonization began with the United States's purchase of Louisiana from France in 1803, Florida from Spain in 1819, of Alaska from Russia in 1867, and the Danish West Indies from Denmark in 1916. Canada became independent of
17556-495: Was the case with Loran C , its primary use was for ship navigation in coastal waters. Fishing vessels were major post-war users, but it was also used on aircraft, including a very early (1949) application of moving-map displays. The system was deployed in the North Sea and was used by helicopters operating to oil platforms . The OMEGA Navigation System was the first truly global radio navigation system for aircraft, operated by
17689-505: Was the only successful slave revolt in history, the world's first black republic was established. It started with the massacre of the white population, between 3,000 and 5,000 white men and women of all ages were killed. Dessalines declared: — Dessalines, first president of the Republic of Haiti, 1804 The most prevalent faiths in the Americas are as follows: Other faiths include Buddhism ; Hinduism ; Sikhism ; Baháʼí Faith ;
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