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87-402: As one of the six NOAA Line Offices, NOAA's National Ocean Service (NOS) observes, studies, and manages the nation's coastal and marine resources. The NOS measures and predicts the coastal and ocean phenomena, protects large areas of the oceans, works to ensure safe navigation , and provides tools and information to protect and restore the coastal and marine resources. NOAA's National Ocean Service

174-469: 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

261-548: 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

348-478: A distance produces 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

435-612: A few meters using time signals transmitted along a line of sight by radio from satellites . Receivers on 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

522-407: 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

609-402: 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,

696-450: 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

783-399: 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

870-418: 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

957-400: 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

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1044-404: 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

1131-754: A targeted, cost-effective, and efficient manner. CRCP funds and equips reef conservation activities by NOAA and its partners in the seven U.S. states and jurisdictions containing coral reefs ( American Samoa , the Commonwealth of the Northern Mariana Islands , Florida , Guam , Hawaii , Puerto Rico , and the United States Virgin Islands ), uninhabited islands including the Northwestern Hawaiian Islands and Pacific Remote Island Areas, and

1218-419: A unifying force in these efforts, providing unbiased NOAA data and tools and providing opportunities for the community to come together to define common goals and find ways to work smarter by working together. Issues include endangered species protection, erosion, and generating better building codes for storm-resistant buildings. The OCM has four programs: The National Coastal Zone Management Program addresses

1305-413: 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

1392-453: 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

1479-412: Is a center for preparation and response to threats to coastal environments, including oil and chemical spills, releases from hazardous waste sites, and marine debris. The Office of Response and Restoration's tasks include: OR&R has three divisions: The Emergency Response Division (ERD) of NOAA's Office of Response and Restoration (OR&R) provides scientific expertise to an incident response. Under

1566-685: Is a national-regional partnership working to understand and predict coastal events - such as storms, wave heights, and sea level change. The National Ocean Service traces its history to 1807, when the Survey of the Coast was created as the U.S. Government's first scientific agency. The agency was renamed the United States Coast Survey in 1836 and the United States Coast and Geodetic Survey in 1878. On October 3, 1970, when

1653-504: Is a network of offices working within the Department of Environmental Protection. An important task of New Jersey's Coastal Management Program is to ensure that coastal resources and ecosystems are conserved to enhance sustainable coastal communities. Some of the issues the program addresses are sustainable and resilient coastal community planning, climate change, ocean planning, and planning for energy facilities. This management program

1740-510: 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 a global system. National Coastal Zone Management Program The National Coastal Zone Management Program is a program of the US government that works with states and territories to protect, restore, and responsibly develop coastal communities, resources, and economies. The program

1827-436: 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

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1914-425: 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

2001-434: 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

2088-494: Is composed of seven programs and two staff offices. The Center for Operational Oceanographic Products and Services (CO-OPS) is a source for water-level and current measurements that support safe and efficient maritime commerce, sound coastal management, and recreation. CO-OPS is composed of four divisions: The Field Operations Division (FOD) operates and maintains all oceanographic and Great Lakes observing systems required to meet CO-OPS' mission objectives. The Division monitors

2175-1053: 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

2262-441: 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

2349-680: Is housed within the National Oceanic and Atmospheric Administration (NOAA) Office for Coastal Management. NOAA is an agency within the Department of Commerce . Participation is voluntary and 34 states and territories participate. States and territories agree to develop state programs that uphold the requirements specified in the founding legislation, the Coastal Zone Management Act of 1972. Every five years, participants review their programs in one or more of

2436-478: 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

2523-453: 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

2610-459: 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,

2697-636: The Environmental Science Services Administration (ESSA) was replaced by NOAA, the Coast and Geodetic Survey was merged with other government scientific agencies to form NOAA. The Coast and Geodetic Survey′s organizational existence lingered until October 9, 1970, when its successor agency within NOAA, the National Ocean Survey, took over its assets and responsibilities. Under the National Ocean Survey,

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2784-956: The National Environmental Satellite, Data, and Information Service (NESDIS). The CRCP was established in 2000 to help fulfill NOAA's responsibilities under the Coral Reef Conservation Act of 2000 (CRCA) and the U.S. Coral Reef Task Force (established by Presidential Executive Order 13089 on Coral Reef Protection). The mission of the CRCP is to protect, conserve, and restore coral reef resources by maintaining healthy ecosystem function. CRCP focuses on four main pillars of work: increase resilience to climate change, reduce land-based sources of pollution, improve fisheries' sustainability, and restore viable coral populations. In strong partnership with local managers, CRCP addresses strategic coral reef management needs in

2871-590: The Screening Quick Reference Tables ( SQuiRT cards), for rapid evaluation of water, sediment and soil contamination. Since 2005, the NOAA Marine Debris Program has been a NOAA program focused on researching, reducing, and preventing debris in the marine environment nationally and globally. The program works with various partners across the U.S. to fulfill its mission. The Integrated Ocean Observing System (IOOS)

2958-909: 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

3045-552: 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

3132-400: 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

3219-456: 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

3306-680: The Damage Assessment, Remediation and Restoration Program (DARRP). This NOAA partnership focuses on the protection and restoration of marine natural resources. The Assessment and Restoration Division is composed of NOAA biologists, toxicologists, ecologists, policy analysts, attorneys, geologists, environmental engineers, and economists. It assesses ecological, environmental ,and economic risk and injury from contamination and ship groundings. In particular, ARD has developed specific expertise in aquatic risk assessment techniques, contaminated sediment issues, and data interpretation. The ARD publishes

3393-543: 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

3480-777: The National Contingency Plan, NOAA has responsibility for providing scientific support to the Federal On-Scene Coordinator (FOSC) for oil and hazardous material spills. To support this mandate, ERD provides response to spill events at any time of day. The Assessment and Restoration Division (ARD), formerly Coastal Protection and Restoration Division (CPRD), is responsible for evaluating and restoring coastal and estuarine habitats damaged by hazardous waste releases, oil spills, and vessel groundings. ARD joined with NOAA's General Counsel for Natural Resources and Office of Habitat Conservation to create

3567-608: The National Ocean Service (NOS) in March 1999 as the focal point for coastal ocean science. Research areas and strategy were selected in response to Federal legislation, stakeholder input, and in concert with scientific expertise and capabilities. Provides navigation products and services that ensure safe and efficient maritime commerce on America's oceans and coastal waters, and in the Great Lakes. OCS consists of

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3654-553: 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

3741-651: 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

3828-660: The Office of Coast Survey took over the Coast and Geodetic Survey′s hydrographic survey duties and its geodetic responsibilities were transferred to the National Geodetic Survey. The Coast and Geodetic Survey's fleet of survey ships temporarily came under the direct control of the National Ocean Survey, although via a phased process during 1972 and 1973 they merged with ships temporarily assigned to NOAA's National Marine Fisheries Service and ships formerly assigned to ESSA′s Environmental Research Laboratories to form

3915-654: The Pacific Freely Associated States ( Federated States of Micronesia , Republic of the Marshall Islands , and Palau ). CRCP supports multiple cross-cutting activities and associated products including the National Coral Reef Monitoring Program and Coral Reef Watch. This NOAA-sponsored website is focused on helping communities address coastal issues and has become one of the most-used resources in

4002-690: 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

4089-471: The accurate accounting of revenues collected through user fees. The Engineering Division establishes observation and analysis requirements for CO-OPS based on the assessment of user/customer needs. The Division also manages the Ocean Systems Test and Evaluation Program (OSTEP) and its associated test facilities. The Division develops new oceanographic measurement systems and techniques to improve

4176-495: 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

4263-421: 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

4350-596: The coastal management community. The National Estuarine Research Reserve System is a network of 29 coastal sites designated to protect and study estuarine systems. Established through the Coastal Zone Management Act, the reserves represent a partnership program between NOAA and the coastal states. NOAA provides funding and national guidance, and each site is managed on a daily basis by a lead state agency or university with input from local partners. The Office of National Geodetic Survey (NGS) provides

4437-493: The content of CO-OPS data/product delivery systems; develops web page services; distributes real-time data to CO-OPS customers; provides information for matters such as litigation and boundary disputes (e.g., certified water level and benchmark information); provides technical assistance to customers regarding the use of CO-OPS products and services; designs new products and services to meet user needs, and maintains customer lists, billing information and accounting procedures to ensure

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4524-608: The continuous operations of navigation and other real-time observing systems to support the protection of life and property. FOD also operates the Ocean Systems Test and Evaluation Facility (OSTEF) to support Requirements and Development Division (RDD), and Information Systems Division (ISD) development efforts. FOD operates equipment to evaluate new observing systems and software modules developed to support NOS mission objectives. The Division installs, documents, operates and maintains CO-OPS measurement systems (e.g., NWLON, PORTS); conducts field reconnaissance and geodetic operations to include

4611-666: 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

4698-557: The establishment, leveling, documentation, and inspection of NOS benchmarks; and provides training in the installation, operation and maintenance of CO-OPS observing equipment. The Oceanographic Division monitors the quality of all data collected by CO-OPS, and produces operational products from this data stream. The Division monitors the performance of all CO-OPS observing systems and reports discrepancies to appropriate Center personnel. The Division performs operational data quality control/data analysis; produces oceanographic products; manages

4785-491: The following areas: wetlands , coastal hazards , public access, marine debris , aquaculture , cumulative and secondary impacts of development, special area management plans, ocean and Great Lakes resources, and energy and government facility siting. NOAA and the U.S. Environmental Protection Agency also jointly administer the Coastal Nonpoint Pollution Control program. The stated goal of

4872-576: The following offices: Established in 2014 when NOAA combined two offices: the Coastal Services Center and the Office of Ocean and Coastal Resource Management. In addition to implementing specific initiatives, a top priority for NOAA's Office for Coastal Management is to unify efforts to make communities more resilient. Many organizations are involved, including the private sector, nonprofits, the scientific community, and all levels of government. The Office for Coastal Management works to be

4959-450: The framework for all positioning activities in the nation. The foundational elements - latitude , longitude , elevation , shoreline information and their changes over time - contribute to informed decision making and impact a wide range of important activities including mapping and charting, navigation, flood risk determination, transportation, land use and ecosystem management. NGS' authoritative spatial data, models, and tools are vital for

5046-426: 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,

5133-480: 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

5220-669: 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

5307-448: 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

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5394-667: 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 ,

5481-411: The nation's coastal issues through a voluntary partnership between the federal government and coastal and Great Lakes states and territories. Authorized by the Coastal Zone Management Act of 1972, the program provides the basis for protecting, restoring, and responsibly developing coastal communities and resources. Currently 34 coastal states participate. While state partners must follow basic requirements,

5568-544: 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

5655-462: 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

5742-774: The network includes a system of 17 national marine sanctuaries: The ONMS also participates in the administration of two marine national monuments , the Papahānaumokuākea Marine National Monument , which it administers jointly with the United States Fish and Wildlife Service and the State of Hawaii , and the Rose Atoll Marine National Monument , which it administers jointly with the U.S. Fish and Wildlife Service. NOAA's Office of Response and Restoration (OR&R)

5829-405: 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

5916-506: 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

6003-476: 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 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

6090-412: 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

6177-626: 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

6264-423: The program also gives states the flexibility to design unique programs that best address their coastal challenges and regulations. NOAA's Coral Reef Conservation Program (CRCP) is a cross-cutting program that brings together expertise from a wide array of NOAA programs and offices in the National Ocean Service (NOS), National Marine Fisheries Service (NMFS), Office of Oceanic and Atmospheric Research (OAR), and

6351-645: The program is to reduce polluted runoff to coastal waters. The six main runoff sources are agriculture , forestry , urban areas, wetlands, modified shorelines and stream channels, and vegetative and other treatment systems. This program was established in 1990 by Section 6217 of the Coastal Zone Act Reauthorization Amendments. New Jersey's Coastal Management Program is part of the National Coastal Zone Management Program. The NJCMP

6438-554: The protection and management of natural and manmade resources and support the economic prosperity and environmental health of the nation. The NGS consists of six divisions: The Office of National Marine Sanctuaries (ONMS) serves as the trustee for the National Marine Sanctuary system, a network of underwater parks encompassing more than 170,000 square miles (128,000 sq nmi; 440,000 km) of Great Lakes and oceanic waters. As of October 11, 2024,

6525-509: The public in the establishment and operation of water level and current measurement stations; and develops/integrates measurement and telemetry systems needed to support CO-OPS activities. The National Centers for Coastal Ocean Science (NCCOS) provides research, scientific information and tools to help balance the nation's ecological, social and economic goals. The research and tools provided are central to addressing coastal issues raised in legislation and NOAA's priorities. NCCOS were formed within

6612-429: 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

6699-517: 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

6786-622: The safety of marine navigation. The Division: develops and issues standard operating procedures, project instructions, and manuals, to guide the operation and maintenance of CO-OPS oceanographic and meteorological measurement systems; prepares measurement requirements (based on tidal zoning) for hydrographic or photogrammetric field surveys, and to support other NOS needs for water level and current information; prepares and monitors interagency agreements, technology transfer agreements and work plans; prepares and administers contracts; provides technical assistance and guidance to other countries, agencies, and

6873-409: 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

6960-412: 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

7047-400: The screen that 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

7134-511: 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 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

7221-609: 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

7308-809: 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

7395-462: 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

7482-550: The unified NOAA fleet operated by the National Ocean Survey's Office of Fleet Operations. As a reflection of its diversifying responsibilities, the National Ocean Survey was renamed the National Ocean Service in 1983. Navigation 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. It

7569-495: 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

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