A harbor or harbour is a sheltered body of water where ships and barges can be docked. The term harbor is used interchangeably with port, a man-made facility built for loading and unloading vessels and dropping off and picking up passengers. Ports include one or more harbors. Alexandria Port in Egypt is an example of a port with two harbors. Harbors may be artificial. An artificial harbor can have deliberately constructed breakwaters, sea walls, or jettys or they can be constructed by dredging, which requires maintenance by further periodic dredging. An example of an artificial harbor is Long Beach Harbor, United States, an array of salt marshes and tidal flats too shallow for modern merchant ships before it was first dredged in the early 20th century. In contrast, a natural harbor is surrounded on several sides by prominences of land. Examples of natural harbors include Sydney Harbour and Trincomalee Harbour in Sri Lanka. Artificial harbors are built for use as ports; the oldest artificial harbor known is the Ancient Egyptian site at Wadi al-Jarf, on the Red Sea coast, at least 4500 years old.
The largest artificially created. Other large and busy artificial harbors include: Port of Houston, United States. Port of Rotterdam, Netherlands. A natural harbor is a landform where a part of a body of water is protected and deep enough to furnish anchorage. Many such harbors are rias. Natural harbors have long been of great strategic naval and economic importance, many great cities of the world are located on them. Having a protected harbor reduces or eliminates the need for breakwaters as it will result in calmer waves inside the harbor; some examples are: Port Hercules in Principality of Monaco. For harbors near the North and South Poles, being ice-free is an important advantage when it is year-round. Examples of these include: Hammerfest, Norway. Vardø, Norway. Although the world's busiest port is a hotly contested title, in 2006 the world's busiest harbor by cargo tonnage was the Port of Shanghai; the following are large natural harbors: Harbor Maintenance Finance and Funding Congressional Research Service "Harbor".
New International Encyclopedia. 1905
The coast known as the coastline or seashore, is the area where land meets the sea or ocean, or a line that forms the boundary between the land and the ocean or a lake. A precise line that can be called a coastline cannot be determined due to the Coastline paradox; the term coastal zone is a region where interaction of the land processes occurs. Both the terms coast and coastal are used to describe a geographic location or region. Edinburgh for example is a city on the coast of Great Britain. A pelagic coast refers to a coast which fronts the open ocean, as opposed to a more sheltered coast in a gulf or bay. A shore, on the other hand, can refer to parts of land adjoining any large body of water, including oceans and lakes; the somewhat related term "" refers to the land alongside or sloping down to a river or body of water smaller than a lake. "Bank" is used in some parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond. While many scientific experts might agree on a common definition of the term "coast", the delineation of the extents of a coast differ according to jurisdiction, with many scientific and government authorities in various countries differing for economic and social policy reasons.
According to the UN atlas, 44% of people live within 150 kilometres of the sea. Tides determine the range over which sediment is deposited or eroded. Areas with high tidal ranges allow waves to reach farther up the shore, areas with lower tidal ranges produce deposition at a smaller elevation interval; the tidal range is influenced by the shape of the coastline. Tides do not cause erosion by themselves. Waves erode coastline. Coastlines with longer shores have more room for the waves to disperse their energy, while coasts with cliffs and short shore faces give little room for the wave energy to be dispersed. In these areas the wave energy breaking against the cliffs is higher, air and water are compressed into cracks in the rock, forcing the rock apart, breaking it down. Sediment deposited by waves comes from eroded cliff faces and is moved along the coastline by the waves; this forms an cliffed coast. Sediment deposited by rivers is the dominant influence on the amount of sediment located on a coastline.
Today riverine deposition at the coast is blocked by dams and other human regulatory devices, which remove the sediment from the stream by causing it to be deposited inland. Like the ocean which shapes them, coasts are a dynamic environment with constant change; the Earth's natural processes sea level rises and various weather phenomena, have resulted in the erosion and reshaping of coasts as well as flooding and creation of continental shelves and drowned river valleys. The coast and its adjacent areas on and off shore are an important part of a local ecosystem: the mixture of fresh water and salt water in estuaries provides many nutrients for marine life. Salt marshes and beaches support a diversity of plants and insects crucial to the food chain; the high level of biodiversity creates a high level of biological activity, which has attracted human activity for thousands of years. More and more of the world's people live in coastal regions. Many major cities have port facilities; some landlocked places have achieved port status by building canals.
The coast is a frontier that nations have defended against military invaders and illegal migrants. Fixed coastal defenses have long been erected in many nations and coastal countries have a navy and some form of coast guard. Coasts those with beaches and warm water, attract tourists. In many island nations such as those of the Mediterranean, South Pacific and Caribbean, tourism is central to the economy. Coasts offer recreational activities such as swimming, surfing and sunbathing. Growth management can be a challenge for coastal local authorities who struggle to provide the infrastructure required by new residents. Coasts face many human-induced environmental impacts; the human influence on climate change is thought to contribute to an accelerated trend in sea level rise which threatens coastal habitats. Pollution can occur from a number of sources: industrial debris. Fishing has declined due to habitat degradation, trawling and climate change. Since the growth of global fishing enterprises after the 1950s, intensive fishing has spread from a few concentrated areas to encompass nearly all fisheries.
The scraping of the ocean floor in bottom dragging is devastating to coral and other long-lived species that do not recover quickly. This destruction alters the functioning of the ecosystem and can permanently alter species composition and biodiversity. Bycatch, the capture of unintended species in the course of fishing, is returned to the ocean only to die from injuries or exposure. Bycatch represents about a quarter of all marine catch. In the case of shrimp capture, the bycatch is five times larger, it is believed that melting Arctic ice will cause sea levels to rise and flood coas
The Persian Gulf is a mediterranean sea in Western Asia. The body of water is an extension of the Indian Ocean through the Strait of Hormuz and lies between Iran to the northeast and the Arabian Peninsula to the southwest; the Shatt al-Arab river delta forms the northwest shoreline. The body of water is and internationally known as the "Persian Gulf"; some Arab governments refer to it as the "Arabian Gulf" or "The Gulf", but neither term is recognized internationally. The name "Gulf of Iran" is used by the International Hydrographic Organization; the Persian Gulf was a battlefield of the 1980–1988 Iran–Iraq War, in which each side attacked the other's oil tankers. It is the namesake of the 1991 Gulf War, the air- and land-based conflict that followed Iraq's invasion of Kuwait; the gulf has many fishing grounds, extensive reefs, abundant pearl oysters, but its ecology has been damaged by industrialization and oil spills. The Persian Gulf resides in the Persian Gulf Basin, of Cenozoic origin and related to the subduction of the Arabian Plate under the Zagros Mountains.
The current flooding of the basin started 15,000 years ago due to rising sea levels of the Holocene glacial retreat. This inland sea of some 251,000 square kilometres is connected to the Gulf of Oman in the east by the Strait of Hormuz. In Iran this is called "Arvand Rood", where "Rood" means "river", its length is 989 kilometres, with Iran covering most of the northern coast and Saudi Arabia most of the southern coast. The Persian Gulf is about 56 km wide in the Strait of Hormuz; the waters are overall shallow, with a maximum depth of 90 metres and an average depth of 50 metres. Countries with a coastline on the Persian Gulf are: Iran. Various small islands lie within the Persian Gulf, some of which are the subject of territorial disputes between the states of the region; the International Hydrographic Organization defines the Persian Gulf's southern limit as "The Northwestern limit of Gulf of Oman". This limit is defined as "A line joining Ràs Limah on the coast of Arabia and Ràs al Kuh on the coast of Iran".
The gulf is connected to Indian Ocean through Strait of Hormuz. Writing the water balance budget for the Persian Gulf, the inputs are river discharges from Iran and Iraq, as well as precipitation over the sea, around 180mm/year in Qeshm Island; the evaporation of the sea is high, so that after considering river discharge and rain contributions, there is still a deficit of 416 cubic kilometers per year. This difference is supplied by currents at the Strait of Hormuz; the water from the Gulf has a higher salinity, therefore exits from the bottom of the Strait, while ocean water with less salinity flows in through the top. Another study revealed the following numbers for water exchanges for the Gulf: evaporation = -1.84m/year, precipitation = 0.08m/year, inflow from the Strait = 33.66m/year, outflow from the Strait = -32.11m/year, the balance is 0m/year. Data from different 3D computational fluid mechanics models with spatial resolution of 3 kilometers and depth each element equal to 1–10 meters are predominantly used in computer models.
The Persian Gulf and its coastal areas are the world's largest single source of crude oil, related industries dominate the region. Safaniya Oil Field, the world's largest offshore oilfield, is located in the Persian Gulf. Large gas finds have been made, with Qatar and Iran sharing a giant field across the territorial median line. Using this gas, Qatar has built up a substantial liquefied natural petrochemical industry. In 2002, the Persian Gulf nations of Bahrain, Iraq, Qatar, Saudi Arabia, the UAE produced about 25% of the world's oil, held nearly two-thirds of the world's crude oil reserves, about 35% of the world's natural gas reserves; the oil-rich countries that have a coastline on the Persian Gulf are referred to as the Persian Gulf States. Iraq's egress to the gulf is narrow and blockaded consisting of the marshy river delta of the Shatt al-Arab, which carries the waters of the Euphrates and the Tigris rivers, where the east bank is held by Iran. In 550 BC, the Achaemenid Empire established the first ancient empire in Persis, in the southwestern region of the Iranian plateau.
In the Greek sources, the body of water that bordered this province came to be known as the "Persian Gulf". During the years 550 to 330 BC, coinciding with the sovereignty of the Achaemenid Persian Empire over the Middle East area the whole part of the Persian Gulf and some parts of the Arabian Peninsula, the name of "Pars Sea" is found in the compiled written texts. In the travel account of Pythagoras, several chapters are related to description of his travels accompanied by the Achaemenid king Darius the Great, to Susa and Persepolis, the area is described. From among the writings of others in the same period, there is the inscription and engraving of Darius the Great, installed at junction of waters of Red Sea and the Nile river and the Rome river which belongs to t
A city is a large human settlement. Cities have extensive systems for housing, sanitation, land use, communication, their density facilitates interaction between people, government organizations and businesses, sometimes benefiting different parties in the process. City-dwellers have been a small proportion of humanity overall, but following two centuries of unprecedented and rapid urbanization half of the world population now lives in cities, which has had profound consequences for global sustainability. Present-day cities form the core of larger metropolitan areas and urban areas—creating numerous commuters traveling towards city centers for employment and edification. However, in a world of intensifying globalization, all cities are in different degree connected globally beyond these regions; the most populated city proper is Chongqing while the most populous metropolitan areas are the Greater Tokyo Area, the Shanghai area, Jabodetabek. The cities of Faiyum and Varanasi are among those laying claim to longest continual inhabitation.
A city is distinguished from other human settlements by its great size, but by its functions and its special symbolic status, which may be conferred by a central authority. The term can refer either to the physical streets and buildings of the city or to the collection of people who dwell there, can be used in a general sense to mean urban rather than rural territory. A variety of definitions, invoking population, population density, number of dwellings, economic function, infrastructure, are used in national censuses to classify populations as urban. Common population definitions for a city range between 1,500 and 50,000 people, with most U. S. states using a minimum between 5,000 inhabitants. However, some jurisdictions set no such minimums. In the United Kingdom, city status is awarded by the government and remains permanently, resulting in some small cities, such as Wells and St Davids. According to the "functional definition" a city is not distinguished by size alone, but by the role it plays within a larger political context.
Cities serve as administrative, commercial and cultural hubs for their larger surrounding areas. Examples of settlements called city which may not meet any of the traditional criteria to be named such include Broad Top City and City Dulas, Anglesey, a hamlet; the presence of a literate elite is sometimes included in the definition. A typical city has professional administrators and some form of taxation to support the government workers; the governments may be based on heredity, military power, work projects such as canal building, food distribution, land ownership, commerce, finance, or a combination of these. Societies that live in cities are called civilizations; the word city and the related civilization come, via Old French, from the Latin root civitas meaning citizenship or community member and coming to correspond with urbs, meaning city in a more physical sense. The Roman civitas was linked with the Greek "polis"—another common root appearing in English words such as metropolis. Urban geography deals both with their internal structure.
Town siting has varied through history according to natural, technological and military contexts. Access to water has long been a major factor in city placement and growth, despite exceptions enabled by the advent of rail transport in the nineteenth century, through the present most of the world's urban population lives near the coast or on a river. Urban areas as a rule cannot produce their own food and therefore must develop some relationship with a hinterland which sustains them. Only in special cases such as mining towns which play a vital role in long-distance trade, are cities disconnected from the countryside which feeds them. Thus, centrality within a productive region influences siting, as economic forces would in theory favor the creation of market places in optimal mutually reachable locations; the vast majority of cities have a central area containing buildings with special economic and religious significance. Archaeologists refer to this area by the Greek term temenos; these spaces reflect and amplify the city's centrality and importance to its wider sphere of influence.
Today cities have downtown, sometimes coincident with a central business district. Cities have public spaces where anyone can go; these include owned spaces open to the public as well as forms of public land such as public domain and the commons. Western philosophy since the time of the Greek agora has considered physical public space as the substrate of the symbolic public sphere. Public art adorns public spaces. Parks and other natural sites within cities provide residents with relief from the hardness and regularity of typical built environments. Urban structure follows one or more basic patterns: geomorphic, concentric and curvilinear. Physical environment constrains the form in which a city is built. If located on a mountainside, urban structure may rely on winding roads, it may be adapted to its means of subsistence. And it may be set up for optimal defense given the surrounding landscape. Beyond these "geomorphi
A hand compass is a compact magnetic compass capable of one-hand use and fitted with a sighting device to record a precise bearing or azimuth to a given target or to determine a location. Hand or sighting compasses include instruments with simple notch-and-post alignment, prismatic sights, direct or lensatic sights, mirror/vee sights. With the additional precision offered by the sighting arrangement, depending upon construction, sighting compasses provide increased accuracy when measuring precise bearings to an objective; the term hand compass is used by some in the forestry and surveying professions to refer to a certain type of hand compass optimized for use in those fields known as a forester or cruiser compass. A hand compass may include the various one-hand or'pocket' versions of the surveyor's or geologist's transit. While small portable compasses fitted with mechanical sighting devices have existed for a few hundred years, the first one-hand compass with a sighting device appeared around 1885.
These soon evolved into more elaborate and specialized models such as the Brunton Pocket Transit patented in 1894. Hand compasses were soon employed in the practice of forestry, archaeology, preliminary cartography and land surveying. In the United States, the hand compass became popular among foresters seeking a compass to plot and estimate stands of timber. While the Pocket Transit was more than adequate for such work, it was expensive. A new type of hand compass was introduced: the forester or cruiser compass. Traditionally, cruiser compasses featured a sighting notch, a mechanically-damped or "dry" needle, adjustable declination and a large dial marked in individual degrees using counterclockwise calibration. A screw base for a tripod or jacob staff was fitted as well. By the late 1960s many foresters had begun using more modern liquid-damped compass designs, including mirror-sight protractor models such as the Silva Type 15 Ranger or the Suunto MC-1; these compasses were fast to use along straight cruise lines and were sufficiently accurate for most forestry applications.
On the other hand, speleologists, archaeologists and foresters engaged in precision survey work used direct-reading models such as the Suunto KB-14, prismatic compasses such as Suunto KB-77 or the traditional Brunton Pocket Transit. Many models featured an optional quadrant scale instead of an azimuthal system. By using a hand compass in combination with aerial photographs and maps a person can determine his/her location in the field, determine direction to landmarks or destinations, estimate distance, estimate area, find points of interest. For increased accuracy, many professional hand compasses continue to be fitted with tripod mounts. While the hand compass continues to be employed in such work, it has been supplanted in recent years by use of the GPS, or Global Positioning System receiver; the marine hand compass, or hand-bearing compass as it is termed in nautical use, has been used by small-boat or inshore sailors since at least the 1920s to keep a running course or to record precise bearings to landmarks on shore in order to determine position via the resection technique.
Instead of a magnetized needle or disc, most hand bearing compasses feature liquid damping with a floating card design. Equipped with a viewing prism, the hand bearing compass allows instant reading of forward bearings from the user to an object or vessel, some provide the reciprocal bearing as well. Modern examples of marine hand bearing compasses include the Suunto KB-14 and KB-77, the Plastimo Iris 50; these compasses have battery-illuminated or photoluminescent degree dials for use in low light or darkness. Avery, T. E. Burkhart, H. E. Forest Measurements, 5th ed. New York:McGraw-Hill Johnson, The Ultimate Desert Handbook: A Manual for Desert Hikers and Travelers, McGraw-Hill Professional, ISBN 0-07-139303-X, 9780071393034 Mooers Jr. Robert L. Finding Your Way In The Outdoors, Outdoor Life Press, ISBN 0-943822-41-6 Rutstrum, The Wilderness Route Finder, University of Minnesota Press, ISBN 0-8166-3661-3
Radar is a detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, spacecraft, guided missiles, motor vehicles, weather formations, terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna and a receiver and processor to determine properties of the object. Radio waves from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed. Radar was developed secretly for military use by several nations in the period before and during World War II. A key development was the cavity magnetron in the UK, which allowed the creation of small systems with sub-meter resolution; the term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging The term radar has since entered English and other languages as a common noun, losing all capitalization.
The modern uses of radar are diverse, including air and terrestrial traffic control, radar astronomy, air-defense systems, antimissile systems, marine radars to locate landmarks and other ships, aircraft anticollision systems, ocean surveillance systems, outer space surveillance and rendezvous systems, meteorological precipitation monitoring and flight control systems, guided missile target locating systems, ground-penetrating radar for geological observations, range-controlled radar for public health surveillance. High tech radar systems are associated with digital signal processing, machine learning and are capable of extracting useful information from high noise levels. Radar is a key technology that the self-driving systems are designed to use, along with sonar and other sensors. Other systems similar to radar make use of other parts of the electromagnetic spectrum. One example is "lidar". With the emergence of driverless vehicles, Radar is expected to assist the automated platform to monitor its environment, thus preventing unwanted incidents.
As early as 1886, German physicist Heinrich Hertz showed that radio waves could be reflected from solid objects. In 1895, Alexander Popov, a physics instructor at the Imperial Russian Navy school in Kronstadt, developed an apparatus using a coherer tube for detecting distant lightning strikes; the next year, he added a spark-gap transmitter. In 1897, while testing this equipment for communicating between two ships in the Baltic Sea, he took note of an interference beat caused by the passage of a third vessel. In his report, Popov wrote that this phenomenon might be used for detecting objects, but he did nothing more with this observation; the German inventor Christian Hülsmeyer was the first to use radio waves to detect "the presence of distant metallic objects". In 1904, he demonstrated the feasibility of detecting a ship in dense fog, but not its distance from the transmitter, he obtained a patent for his detection device in April 1904 and a patent for a related amendment for estimating the distance to the ship.
He got a British patent on September 23, 1904 for a full radar system, that he called a telemobiloscope. It operated on a 50 cm wavelength and the pulsed radar signal was created via a spark-gap, his system used the classic antenna setup of horn antenna with parabolic reflector and was presented to German military officials in practical tests in Cologne and Rotterdam harbour but was rejected. In 1915, Robert Watson-Watt used radio technology to provide advance warning to airmen and during the 1920s went on to lead the U. K. research establishment to make many advances using radio techniques, including the probing of the ionosphere and the detection of lightning at long distances. Through his lightning experiments, Watson-Watt became an expert on the use of radio direction finding before turning his inquiry to shortwave transmission. Requiring a suitable receiver for such studies, he told the "new boy" Arnold Frederic Wilkins to conduct an extensive review of available shortwave units. Wilkins would select a General Post Office model after noting its manual's description of a "fading" effect when aircraft flew overhead.
Across the Atlantic in 1922, after placing a transmitter and receiver on opposite sides of the Potomac River, U. S. Navy researchers A. Hoyt Taylor and Leo C. Young discovered that ships passing through the beam path caused the received signal to fade in and out. Taylor submitted a report, suggesting that this phenomenon might be used to detect the presence of ships in low visibility, but the Navy did not continue the work. Eight years Lawrence A. Hyland at the Naval Research Laboratory observed similar fading effects from passing aircraft. Before the Second World War, researchers in the United Kingdom, Germany, Japan, the Netherlands, the Soviet Union, the United States, independently and in great secrecy, developed technologies that led to the modern version of radar. Australia, New Zealand, South Africa followed prewar Great Britain's radar development, Hungary generated its radar technology during the war. In France in 1934, following systematic studies on the split-anode magnetron, the research branch of the Compagnie Générale de Télégraphie Sans Fil headed by Maurice Ponte with Henri Gutton, Sylvain Berline and M. Hugon, began developing an obstacle-locatin
Echo sounding is a type of sonar used to determine the depth of water by transmitting sound waves into water. The time interval between emission and return of a pulse is recorded, used to determine the depth of water along with the speed of sound in water at the time; this information is typically used for navigation purposes or in order to obtain depths for charting purposes. Echo sounding can refer to hydroacoustic "echo sounders" defined as active sound in water used to study fish. Hydroacoustic assessments have traditionally employed mobile surveys from boats to evaluate fish biomass and spatial distributions. Conversely, fixed-location techniques use stationary transducers to monitor passing fish; the word sounding is used for all types of depth measurements, including those that don't use sound, is unrelated in origin to the word sound in the sense of noise or tones. Echo sounding is a more rapid method of measuring depth than the previous technique of lowering a sounding line until it touched bottom.
Distance is measured by multiplying half the time from the signal's outgoing pulse to its return by the speed of sound in the water, 1.5 kilometres per second For precise applications of echosounding, such as hydrography, the speed of sound must be measured by deploying a sound velocity probe into the water. Echo sounding is a special purpose application of sonar used to locate the bottom. Since a traditional pre-SI unit of water depth was the fathom, an instrument used for determining water depth is sometimes called a fathometer; the first practical fathometer was invented by Herbert Grove Dorsey and patented in 1928. Most charted ocean depths use an standard sound speed. Where greater accuracy is required average and seasonal standards may be applied to ocean regions. For high accuracy depths restricted to special purpose or scientific surveys, a sensor may be lowered to measure the temperature and salinity; these factors are used to calculate the actual sound speed in the local water column.
This latter technique is used by US Office of Coast Survey for navigational surveys of US coastal waters. See NOAA Field Procedures Manual, Office of Coast Survey website; as well as an aid to navigation, echo sounding is used for fishing. Variations in elevation represent places where fish congregate. Schools of fish will register. A fishfinder is an echo sounding device used by both commercial fishers. In areas where detailed bathymetry is required, a precise echo sounder may be used for the work of hydrography. There are many considerations when evaluating such a system, not limited to the vertical accuracy, acoustic beamwidth of the transmit/receive beam and the acoustic frequency of the transducer; the majority of hydrographic echosounders are dual frequency, meaning that a low frequency pulse can be transmitted at the same time as a high frequency pulse. As the two frequencies are discrete, the two return signals do not interfere with each other. There are many advantages of dual frequency echosounding, including the ability to identify a vegetation layer or a layer of soft mud on top of a layer of rock.
Most hydrographic operations use a 200 kHz transducer, suitable for inshore work up to 100 metres in depth. Deeper water requires a lower frequency transducer as the acoustic signal of lower frequencies is less susceptible to attenuation in the water column. Used frequencies for deep water sounding are 33 kHz and 24 kHz; the beamwidth of the transducer is a consideration for the hydrographer, as to obtain the best resolution of the data gathered a narrow beamwidth is preferable. This is important when sounding in deep water, as the resulting footprint of the acoustic pulse can be large once it reaches a distant sea floor. In addition to the single beam echo sounder, there are echo sounders that are capable of receiving many return "pings"; these systems are detailed further in the section called multibeam echosounder. Echo sounders are used in laboratory applications to monitor sediment transport and erosion processes in scale models; these can be used to create plots of 3D contours. The required precision and accuracy of the hydrographic echo sounder is defined by the requirements of the International Hydrographic Organization for surveys that are to be undertaken to IHO standards.
These values are contained within IHO publication S44. In order to meet these standards, the surveyor must consider not only the vertical and horizontal accuracy of the echo sounder and transducer, but the survey system as a whole. A motion sensor may be used the heave component to reduce soundings for the motion of the vessel experienced on the water's surface. Once all of the uncertainties of each sensor are established, the hydrographer will create an uncertainty budget to determine whether the survey system meets the requirements laid down by IHO. Different hydrographic organisations will have their own set of field procedures and manuals to guide their surveyors to meet the required standards. Two examples are the US Army Corps of Engineers publication EM110-2-1003, the NOAA'Field Procedures Manual'. German inventor Alexander Behm was granted German patent No. 282009 for the invention of echo sounding on 22 July 1913. One of