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73-485: (Redirected from Indian Scout ) Indian scout or Indian Scout may refer to: A reconnaissance , soldier or paramilitary that operates in the bush, or from a native population Historically, a Native American skilled in tracking United States Army Indian Scouts Indian Scout (motorcycle) , a motorcycle built by the Indian Motorcycle Company

146-480: A computer-aided design (CAD) package, usually Autocad . Although the accuracy of crowd-sourced surveying can rarely reach the standards of traditional methods, the algorithms used rely on a high data density to produce final results that are more accurate than single measurements. A comparison of crowd-sourced surveys with multibeam surveys indicates an accuracy of crowd-sourced surveys of around plus or minus 0.1 to 0.2 meter (about 4 to 8 inches). NOAA maintains

219-414: A pontoon bridge for crossing water obstacles. Sanitary epidemiological reconnaissance implies collection and transfer of all data available on sanitary and epidemiological situation of the area of possible deployment and action of armed forces , the same data for the neighboring and enemy armed forces. The aim for the reconnaissance is to clear up the reasons of the specific disease origin- sources of

292-405: A relatively short battle that lasted only 9 days. When referring to reconnaissance, a commander's full intention is to have a vivid picture of his battlespace . The commander organizes the reconnaissance platoon based on: This analysis determines whether the platoon uses single or multiple elements to conduct the reconnaissance, whether it pertains to area , zone , or route reconnaissance ,

365-607: A boy scout or girl scout who is American Indian, see American Indian Scouting Association a boy scout or girl scout from India, see Scouting and Guiding in India Ladakh Scouts , an infantry regiment of the Indian Army Davy Crockett, Indian Scout , 1950 Western film See also [ edit ] Indian (disambiguation) Scout (disambiguation) Indian Guides (disambiguation) Indian auxiliaries Topics referred to by

438-431: A rule. They expect and are prepared to fight to obtain the desired information. Often they assign supplementary tasks to their reconnaissance units, such as sabotage behind enemy lines, harassment, or counter-reconnaissance. Only enough reconnaissance troops are sent on a mission to assure superiority in the area to be reconnoitred. Reserves are kept on hand to be committed when the reconnaissance must be intensified, when

511-404: A single vertical grazing angle. The first MBES generation was dedicated to mapping the seafloor in deep water. Those pioneering MBES made little, or no, explicit use of the amplitudes, as their objective was to obtain accurate measurements of the bathymetry (representing both the peaks and deeps). Furthermore, their technical characteristics did not make it easy to observe spatial variations in

584-453: A socio-cultural backdrop. It is information developed from data related to civil areas, structures, capabilities, organizations, people, and events, within the civil component of the commander's operational environment that can be processed to increase situational awareness and understanding. The type of civil information that is needed in order to support military operations varies based on the environment and situation. Route reconnaissance

657-414: A specified area; the military commander may utilize his reconnaissance assets to conduct an area reconnaissance to avoid being surprised by unsuitable terrain conditions, or most importantly, unexpected enemy forces. The area could be a town, ridge-line, woods, or another feature that friendly forces intend to occupy, pass through, or avoid. Within an area of operation (AO), area reconnaissance can focus

730-491: A thorough survey as a practical matter could include only a limited number of sounding measurements relative to the area being surveyed, inevitably leaving gaps in coverage between soundings. In 1904, wire-drag surveys were introduced into hydrography, and the United States Coast and Geodetic Survey ′s Nicholas H. Heck played a prominent role in developing and perfecting the technique between 1906 and 1916. In

803-403: A vessel to be gathered in a series of lines spaced at a specified distance. However, it shared the weakness of earlier methods by lacking depth information for areas in between the strips of sea bottom the vessel sounded. A multibeam echosounder (MBES) is a type of sonar that is used to map the seabed . It emits acoustic waves in a fan shape beneath its transceiver . The time it takes for

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876-432: Is a specific discipline of hydrographic survey primarily concerned with the description of the condition of the seabed and the condition of the subsea oilfield infrastructure that interacts with it. Hydrographic offices evolved from naval heritage and are usually found within national naval structures, for example Spain's Instituto Hidrográfico de la Marina . Coordination of those organizations and product standardization

949-428: Is assigned to gain detailed information about enemy forces within the zone, or when the enemy situation is vague by which the information concerning cross-country traffic-ability is desired. The reconnaissance provides the commander with a detailed picture of how the enemy has occupied the zone, enabling him to choose the appropriate course-of-action. As the platoon conducts this type of zone reconnaissance, its emphasis

1022-1051: Is derived from the Middle French word reconoissance . Reconnaissance conducted by ground forces includes special reconnaissance , armored reconnaissance , amphibious reconnaissance and civil reconnaissance. Aerial reconnaissance is reconnaissance carried out by aircraft (of all types including balloons and uncrewed aircraft). The purpose is to survey weather conditions, map terrain, and may include military purposes such as observing tangible structures, particular areas, and movement of enemy forces. Naval forces use aerial and satellite reconnaissance to observe enemy forces. Navies also undertake hydrographic surveys and intelligence gathering . Reconnaissance satellites provide military commanders with photographs of enemy forces and other intelligence. Military forces also use geographical and meteorological information from Earth observation satellites . Types of reconnaissance: The techniques and objectives are not mutually exclusive; it

1095-616: Is different from Wikidata All article disambiguation pages All disambiguation pages Reconnaissance The types of reconnaissance include patrolling the local area of operations and long-range reconnaissance patrols , which are tasks usually realized in the United States of America by U.S. Army Rangers , cavalry scouts , and military intelligence specialists, using navy ships and submarines , reconnaissance aircraft , satellites to collect raw intelligence; and establishing observation posts . Moreover, espionage

1168-408: Is different from reconnaissance, because spies work as civilians in enemy territory. Reconnaissance is a mission to obtain information by visual observation or other detection methods, about the activities and resources of an enemy or potential enemy, or about the meteorologic, hydrographic, or geographic characteristics of a particular area. Reconnaissance (US Army FM 7-92; Chap. 4) The word

1241-402: Is imperative that a scout should know the history, tradition, religion, social customs, and superstitions of whatever country or people he is called on to work in or among. This is almost as necessary as to know the physical character of the country, its climate and products. Certain people will do certain things almost without fail. Certain other things, perfectly feasible, they will not do. There

1314-561: Is no danger of knowing too much of the mental habits of an enemy. One should neither underestimate the enemy nor credit him with superhuman powers. Fear and courage are latent in every human being, though roused into activity by very diverse means. Hydrographic survey Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging , offshore wind farms, offshore oil exploration and drilling and related activities. Surveys may also be conducted to determine

1387-528: Is on determining the enemy's locations, strengths, and weaknesses. This is the most thorough and complete reconnaissance mission and therefore is very time-intensive. A tracker needs to pay close attention to both the environment and the psychology of their enemy. Knowledge of human psychology, sociology, and cultural backgrounds is necessary to know the actions of the enemy and what they will do or where they will go next. Chief of Scouts Frederick Russell Burnham commented on reconnaissance and scouts, saying: It

1460-448: Is oriented on a given route (e.g., a road, a railway, a waterway; i.e., a narrow axis or a general direction of attack) to provide information on route conditions or activities along the route. A military commander relies on information about locations along his determined route: which of those that would provide best cover and concealment; bridge by construction type, dimensions, and classification; or for landing zones or pickup zones, if

1533-530: Is the process of gathering a broad spectrum of civil information about a specific population in support of military operations. It is related to and often performed in conjunction with infrastructure reconnaissance (assessment and survey). Normally the focus of collection in the operational area for civil reconnaissance is collecting civil information relating to the daily interaction between civilians and military forces. Civil information encompasses relational, temporal, geospatial and behavioral information captured in

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1606-435: Is to be logged and rendered as a survey deliverable." in a set of contract survey requirements, is a clear indication that the wider hydrographic community is embracing the benefits that can be accrued by employing MBES technology and, in particular, are accepting as a fact that a MBES which provides acoustic backscatter data is a valuable tool of the trade. The introduction of multispectral multibeam echosounders continues

1679-579: Is up to the commander whether they are carried out separately or by the same unit. Reconnaissance-in-force (RIF) is a type of military operation or military tactic used specifically to probe an enemy's combat ability. While typical reconnaissance forces are small and armed only for self-defense, RIF use considerable (but not decisive) force in order to elicit a strong reaction by the enemy that more accurately reveals its own strength, deployment, preparedness, determination, and other tactical data. The RIF units can then fall back and report this data, or expand

1752-511: Is voluntarily joined with the goal of improving hydrography and safe navigation is conducted by the International Hydrographic Organization (IHO). The IHO publishes Standards and Specifications followed by its Member States as well as Memoranda of Understanding and Co-operative Agreements with hydrographic survey interests. The product of such hydrography is most often seen on nautical charts published by

1825-484: The Wayback Machine and ARGUS. Here, volunteer vessels record position, depth, and time data using their standard navigation instruments, and then the data is post-processed to account for speed of sound, tidal, and other corrections. With this approach there is no need for a specific survey vessel, or for professionally qualified surveyors to be on board, as the expertise is in the data processing that occurs once

1898-418: The infection in various extreme situations, including local wars and armed conflicts , the ways of the infection transfer and all factors promoting to the infestation . After the armed forces have become stationary during wartime and emergency of peacetime the sanitary epidemiological reconnaissance turns into sanitary and epidemiological surveillance and medical control of vital and communal activity of

1971-433: The 1950s, 1960s and 1970s eventually made the wire-drag system obsolete. Sidescan sonar could create images of underwater obstructions with the same fidelity as aerial photography , while multibeam systems could generate depth data for 100 percent of the bottom in a surveyed area. These technologies allowed a single vessel to do what wire-drag surveying required two vessels to do, and wire-drag surveys finally came to an end in

2044-835: The 20th century. So valuable was wire-drag surveying in the United States that for decades the U.S. Coast and Geodetic Survey, and later the National Oceanic and Atmospheric Administration, fielded a pair of sister ships of identical design specifically to work together on such surveys. USC&GS Marindin and USC&GS Ogden conducted wire-drag surveys together from 1919 to 1942, USC&GS Hilgard (ASV 82) and USC&GS Wainwright (ASV 83) took over from 1942 to 1967, and USC&GS Rude (ASV 90) (later NOAAS Rude (S 590) ) and USC&GS Heck (ASV 91) (later NOAAS Heck (S 591) ) worked together on wire-drag operations from 1967. The rise of new electronic technologies – sidescan sonar and multibeam swath systems – in

2117-546: The National Ocean Survey (NOS) established a NOS study team to conduct investigations to determine the functional specifications for a replacement shallow water depth sounder. The outcome of the study was a class of vertical-beam depth sounders, which is still widely used. It simultaneously pinged at two acoustic frequencies, separated by more than 2 octaves, making depth and echo-amplitude measurements that were concurrent, both spatially and temporally, albeit at

2190-467: The acoustic backscatter angular response function to discriminate between different sediment types. Multispectral multibeam echosounders reinforces the fact that spatially and temporally coincident backscatter, from any given seabed, at widely separated acoustic frequencies provides separate and unique images of the seascape. Crowdsourcing also is entering hydrographic surveying, with projects such as OpenSeaMap , TeamSurv Archived 29 December 2020 at

2263-650: The aid of improved collection techniques and computer processing, the data is collected under one standard and extracted for specific use. After data is collected, it has to undergo post-processing. A massive amount of data is collected during the typical hydrographic survey, often several soundings per square foot . Depending on the final use intended for the data (for example, navigation charts , Digital Terrain Model , volume calculation for dredging , topography , or bathymetry ) this data must be thinned out. It must also be corrected for errors (i.e., bad soundings,) and for

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2336-417: The armed forces. Area reconnaissance refers to the observation, and information obtained, about a specified location and the area around it; it may be terrain-oriented and/or force-oriented. Ideally, a reconnaissance platoon, or team, would use surveillance or vantage (static) points around the objective to observe, and the surrounding area. This methodology focuses mainly prior to moving forces into or near

2409-435: The conflict into a full engagement if enemy weaknesses are revealed. Other methods consist of hit-and-run tactics using rapid mobility, and in some cases light-armored vehicles for added fire superiority, as the need arises. Maintaining active RIF can be used to limit, or even deny, enemy reconnaissance. Nazi Germany's reconnaissance during World War II is described in the following way: The purpose of reconnaissance and

2482-456: The continual echo returns from a receive beam that is perfectly aligned with the insonification beam using time-after-transmit, a technique that is independent of water depth and the cross-track beam opening angle of the sonar receive transducer. The initial attempt at multibeam imagery employed multiple receive beams, which only partially overlapped the MBES fan-shaped insonification beam, to segment

2555-481: The continual echo returns into intervals that were dependent on water depth and receiver cross-track beam opening angle. Consequently, the segmented intervals were non-uniform in both their length of time and time-after-transmit. The backscatter from each ping in each of the beam-parsed segments was reduced to a single value and assigned to the same geographical coordinates as those assigned to that beam's measured sounding. In subsequent modifications to MBES bottom imaging,

2628-459: The cross-track variation in echo amplitudes, to achieve high quality images of the seabed, it seemed a natural progression that the fan-shaped across-track pattern of insonification associated with the new monotone higher frequency shallow water MBES, might also be exploited for seabed imagery. Images acquired under the initial attempts at MBES bottom imaging were less than stellar, but fortunately improvements were forthcoming. Side scan sonar parses

2701-1113: The data is uploaded to the server after the voyage. Apart from obvious cost savings, this also gives a continuous survey of an area, but the drawbacks are time in recruiting observers and getting a high enough density and quality of data. Although sometimes accurate to 0.1 – 0.2m, this approach cannot substitute for a rigorous systematic survey, where this is required. Nevertheless, the results are often adequate for many requirements where high resolution, high accuracy surveys are not required, are unaffordable or simply have not been done yet. In suitable shallow-water areas lidar (light detection and ranging) may be used. Equipment can be installed on inflatable craft, such as Zodiacs , small craft, autonomous underwater vehicles (AUVs), unmanned underwater vehicles (UUVs), Remote Operated Vehicles (ROV) or large ships, and can include sidescan, single-beam and multibeam equipment. At one time different data collection methods and standards were used in collecting hydrographic data for maritime safety and for scientific or engineering bathymetric charts, but increasingly, with

2774-1002: The dredging, marine construction, oil exploration , and drilling industries. Industrial entities installing submarine communications cables or power require detailed surveys of cable routes prior to installation and increasingly use acoustic imagery equipment previously found only in military applications when conducting their surveys. Specialized companies exist that have both the equipment and expertise to contract with both commercial and governmental entities to perform such surveys . Companies, universities, and investment groups will often fund hydrographic surveys of public waterways prior to developing areas adjacent those waterways. Survey firms are also contracted to survey in support of design and engineering firms that are under contract for large public projects. Private surveys are also conducted before dredging operations and after these operations are completed. Companies with large private slips, docks, or other waterfront installations have their facilities and

2847-528: The early 1990s. Vessels were freed from working together on wire-drag surveys, and in the U.S. National Oceanic and Atmospheric Administration (NOAA), for example, Rude and Heck operated independently in their later years. Single-beam echosounders and fathometers began to enter service in the 1930s which used sonar to measure the depth beneath a vessel. This greatly increased the speed of acquiring sounding data over that possible with lead lines and sounding poles by allowing information on depths beneath

2920-464: The early acoustic sounders were primarily based on the ability of magneostrictive and piezoelectric materials whose physical dimensions could be modified by means of electrical current or voltage. Eventually it became apparent, that while the operating frequency of the early single vertical beam acoustic sounders had little, or no, bearing on the measured depths when the bottom was hard (composed primarily of sand, pebbles, cobbles, boulders, or rock), there

2993-455: The echo amplitudes. Subsequent to the early MBES bathymetric surveys and at the time when single frequency side scan sonar had begun to produce high quality images of the seabed that were capable of providing a degree of discrimination between different types of sediments, the potential of the echo amplitudes from a MBES was recognized. With Marty Klein's introduction of dual frequency (nominally 100 kHz and 500 kHz) side scan sonar, it

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3066-408: The echo sequence in each of the beam-parsed intervals was designated as a snippet. On each ping, each snippet from each beam was additionally parsed according to time-after-transmit. Each of the echo amplitude measurements made within a snippet from a particular beam was assigned a geographical position based on linear interpolation between positions assigned to the soundings measured, on that ping, in

3139-431: The effects of tides , heave , water level salinity and thermoclines (water temperature differences) as the velocity of sound varies with temperature and salinity and affects accuracy. Usually the surveyor has additional data collection equipment on site to measure and record the data required for correcting the soundings. The final output of charts can be created with a combination of specialty charting software or

3212-425: The enemy force to reveal their location by moving or by returning fire. Reconnaissance-pull is a tactic that is applied at the regiment to division level and defined as locating and rapidly exploiting enemy weaknesses. It is the ability to determine enemy positions and create exploitable gaps through which friendly forces can pass while avoiding obstacles and strong points. A textbook example of reconnaissance-pull

3285-422: The following techniques may be used as long as the fundamentals of reconnaissance are applied. Scouts may also have different tasks to perform for their commanders of higher echelons, for example: the engineer reconnaissance detachments will try to identify difficult terrain in the path of their formation, and attempt to reduce the time it takes to transit the terrain using specialist engineering equipment such as

3358-599: The force from becoming surprised. It is paramount to obtain information about the available space in which a force can maneuver without being forced to bunch up due to obstacles. Terrain-oriented route reconnaissance allows the commander to obtain information and capabilities about the adjacent terrain for maneuvering his forces, to include, any obstacles (minefields, barriers, steep ravines, marshy areas, or chemical, biological, radiological, and nuclear contamination) that may obstruct vehicle movement—on routes to, and in, his assigned area of operations. This requirement includes

3431-691: The national agencies and required by the International Maritime Organization (IMO), the Safety of Life at Sea (SOLAS) and national regulations to be carried on vessels for safety purposes. Increasingly those charts are provided and used in electronic form unders IHO standards. Governmental entities below the national level conduct or contract for hydrographic surveys for waters within their jurisdictions with both internal and contract assets. Such surveys commonly are conducted by national organizations or under their supervision or

3504-429: The need arises. In many cases, the commander may act upon a force-oriented route reconnaissance by which the enemy could influence movement along that route. For the reconnaissance platoons, or squads, stealth and speed—in conjunction with detailed intelligence-reporting—are most important and crucial. The reconnaissance platoon must remain far enough ahead of the maneuver force to assist in early warning and to prevent

3577-421: The obstruction was encountered. This method revolutionized hydrographic surveying, as it allowed a quicker, less laborious, and far more complete survey of an area than did the use of lead lines and sounding poles. From a navigational safety point of view, a wire-drag survey would not miss a hazard to navigation that projected above the drag wire depth. Prior to the advent of sidescan sonar , wire-drag surveying

3650-464: The open water near their facilities surveyed regularly, as do islands in areas subject to variable erosion such as in the Maldives. The history of hydrographic surveying dates almost as far back as that of sailing . For many centuries, a hydrographic survey required the use of lead lines – ropes or lines with depth markings attached to lead weights to make one end sink to the bottom when lowered over

3723-423: The original force meets strong enemy opposition, or when the direction and area to be reconnoitred are changed. The Germans encourage aggressive action against enemy security forces. When their reconnaissance units meet superior enemy forces, they fight a delaying action while other units attempt to flank the enemy. Reconnaissance-by-fire (or speculative fire ) is the act of firing at likely enemy positions to cause

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3796-406: The output data set. Those positions are based on the backscatter measurements themselves and not by interpolation from some other derived data set. Consequently, multispectral multibeam imagery is more acute compared to previous multibeam imagery. The inherent precision of the bathymetric data from a multispectral multibeam echosounder is also a benefit to those users that may be attempting to employ

3869-588: The overlapping sets of side scanning across-track grazing angles at the two frequencies were always the same. Following the grounding of the Queen Elizabeth 2 off Cape Cod , Massachusetts , in 1992, the emphasis for shallow water surveying migrated toward full bottom coverage surveys by employing MBES with increasing operating frequencies to further improve the spatial resolution of the soundings. Given that side scan sonar, with its across-track fan-shaped swath of insonification, had successfully exploited

3942-402: The progressive advances in hydrography. In particular, multispectral multibeam echosounders not only provide "multiple look" depth measurements of a seabed, they also provide multispectral backscatter data that are spatially and temporally coincident with those depth measurements. A multispectral multibeam echosounder directly computes a position of origin for each of the backscatter amplitudes in

4015-404: The raw data collected through hydrographic survey into information usable by the end user . Hydrography is collected under rules which vary depending on the acceptance authority. Traditionally conducted by ships with a sounding line or echo sounding , surveys are increasingly conducted with the aid of aircraft and sophisticated electronic sensor systems in shallow waters. Offshore survey

4088-455: The reconnaissance on the specific area that is critical to the commander. This technique of focusing the reconnaissance also permits the mission to be accomplished more quickly. Area reconnaissance can thus be a stand-alone mission or a task to a section or the platoon. The commander analyzes the mission to determine whether the platoon will conduct these types of reconnaissance separately or in conjunction with each other. Civil reconnaissance

4161-418: The route of subsea cables such as telecommunications cables, cables associated with wind farms, and HVDC power cables. Strong emphasis is placed on soundings, shorelines, tides, currents, seabed and submerged obstructions that relate to the previously mentioned activities. The term hydrography is used synonymously to describe maritime cartography , which in the final stages of the hydrographic process uses

4234-420: The same term [REDACTED] This disambiguation page lists articles associated with the title Indian scout . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Indian_scout&oldid=941466686 " Category : Disambiguation pages Hidden categories: Short description

4307-410: The shallow (peak) soundings in the bottom data were retained in preference to deeper soundings in the sounding record. During that same time period, early side scan sonar was introduced into the operational practices of shallow water hydrographic surveying. The frequencies of the early side scan sonars were a matter of engineering design expediency and the most important aspect of the side scanning echoes

4380-470: The side of a ship or boat – and sounding poles, which were poles with depth markings which could be thrust over the side until they touched bottom. In either case, the depths measured had to be read manually and recorded, as did the position of each measurement with regard to mapped reference points as determined by three-point sextant fixes. The process was labor-intensive and time-consuming and, although each individual depth measurement could be accurate, even

4453-729: The size of trees and the density of forests due to their effects on vehicle movement. Route reconnaissance also allows the observation for fields of fire along the route and adjacent terrain. This information assists planners as a supplement to map information. Zone reconnaissance focuses on obtaining detailed information before maneuvering their forces through particular, designated locations. It can be terrain-oriented, force-oriented, or both, as it acquire this information by reconnoitering within—and by maintaining surveillance over—routes, obstacles (to include nuclear-radiological, biological, and chemical contamination), and resources within an assigned location. Also, force-oriented zone reconnaissance

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4526-425: The sound waves to reflect off the seabed and return to the receiver is used to calculate the water depth. Unlike other sonars and echo sounders , MBES uses beamforming to extract directional information from the returning soundwaves, producing a swath of depth soundings from a single ping. Explicit inclusion of phraseology like: "For all MBES surveys for LINZ, high resolution, geo-referenced backscatter intensity

4599-477: The south-west which were more favorable for an amphibious landing. American forces quickly changed their landing location to the northern beaches and planned a small and hasty " deception " operation off the southern beach, which resulted in a complete surprise for the Japanese forces. As a result, American forces were able to fight the Japanese force on land, where they had the advantage, leading to light losses and

4672-557: The standards they have approved, particularly when the use is for the purposes of chart making and distribution or the dredging of state-controlled waters. In the United States, there is coordination with the National Hydrography Dataset in survey collection and publication. State environmental organizations publish hydrographic data relating to their mission. Commercial entities also conduct large-scale hydrographic and geophysical surveying, particularly in

4745-496: The trajectory of technological innovations providing the hydrographic surveying community with better tools for more rapidly acquiring better data for multiple uses. A multispectral multibeam echosounder is the culmination of many progressive advances in hydrography from the early days of acoustic soundings when the primary concern about the strength of returning echoes from the bottom was whether, or not, they would be sufficiently large to be noted (detected). The operating frequencies of

4818-437: The two adjacent cross-track beams. The snippet modification to MBES imagery significantly improved the quality of the imagery by increasing the number of echo amplitude measurements available to be rendered as a pixel in the image and also by having a more uniform spatial distribution of the pixels in the image which represented an actual measured echo amplitude. The introduction of multispectral multibeam echosounders continued

4891-463: The types of units employed to obtain information are similar in the U.S. and the German Armies. German tactical principles of reconnaissance, however, diverge somewhat from those of the U.S. The Germans stress aggressiveness, attempt to obtain superiority in the area to be reconnoitered, and strive for continuous observation of the enemy. They believe in employing reconnaissance units in force as

4964-400: The wire-drag method, a wire attached to two ships or boats and set at a certain depth by a system of weights and buoys was dragged between two points. If the wire encountered an obstruction, it would become taut and form a "V" shape. The location of the "V" revealed the position of submerged rocks, wrecks, and other obstructions, while the depth at which the wire was set showed the depth at which

5037-481: Was a noticeable frequency dependency of the measured depths when the bottom was soft (composed primarily of silt, mud or flocculent suspensions). It was observed that higher frequency single vertical beam echosounders could provide detectable echo amplitudes from high porosity sediments, even if those sediments appeared to be acoustically transparent at lower frequencies. In the late 1960s, single-beam hydrographic surveys were conducted using widely spaced track lines and

5110-403: Was apparent that spatially and temporally coincident backscatter from any given seabed at those two widely separated acoustic frequencies, would likely provide two separate and unique images of that seascape. Admittedly, the along-track insonification and receiving beam patterns were different, and due to the absence of bathymetric data, the precise backscatter grazing angles were unknown. However,

5183-541: Was documented during the Tinian landings of World War II , utilized by the United States Marine Corps 's Amphibious Reconnaissance Battalion , from V Amphibious Corps . Aerial photography and the confirmation by the amphibious reconnaissance platoons determined that the Japanese defenders had largely ignored the northern beaches of the island, focusing most of their defensive effort on beaches in

5256-455: Was not the value of their amplitudes, but rather that the amplitudes were spatially variable. In fact, important information was deduced about the shape of the bottom and manmade items on the bottom, based on the regions where there were absences of detectable echo amplitudes (shadows) In 1979, in hopes of a technological solution to the problems of surveying in "floating mud", the Director of

5329-402: Was the only method for searching large areas for obstructions and lost vessels and aircraft. Between 1906 and 1916, Heck expanded the capability of wire-drag systems from a relatively limited area to sweeps covering channels 2 to 3 nautical miles (3.7 to 5.6 km; 2.3 to 3.5 mi) in width. The wire-drag technique was a major contribution to hydrographic surveying during much of the rest of

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