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106-650: The major task of the Army Map Service was the compilation, publication and distribution of military topographic maps and related products required by the Armed Forces of the United States. The AMS was also involved in the preparation of extraterrestrial maps of satellite and planetary bodies; the preparation of national intelligence studies; the establishment of world geodetic control networks by both satellite and conventional triangulation methods; and

212-411: A demand for greater precision. This led to technological innovations such as the 1735 Marine chronometer by John Harrison , but also to a reconsideration of the underlying assumptions about the shape of Earth itself. Isaac Newton postulated that the conservation of momentum should make Earth oblate (wider at the equator), while the early surveys of Jacques Cassini (1720) led him to believe Earth

318-621: A few hundred meters depending on where in Europe you look. Mars has no oceans and so no sea level, but at least two martian datums have been used to locate places there. In geodetic coordinates , Earth's surface is approximated by an ellipsoid , and locations near the surface are described in terms of geodetic latitude ( ϕ {\displaystyle \phi } ), longitude ( λ {\displaystyle \lambda } ), and ellipsoidal height ( h {\displaystyle h} ). The ellipsoid

424-406: A formidable Army force clearly demonstrated U.S. resolve and commitment to its friends and allies in the region. Less than one year later, Saddam Hussein would again deploy Iraqi forces close to its border with Kuwait. In August, Third Army/ARCENT provided command and control for a rapid deployment of a heavy brigade task force. Once more, Iraqi threats were met while ARCENT simultaneously conducted

530-650: A forward element at Camp Arifjan , Kuwait . It serves as the echelon above corps for the Army component of CENTCOM , US Central Command, whose area of responsibility (AOR) includes Southwest Asia , some 20 countries of the world, in Africa, Asia, and the Persian Gulf. The Third United States Army was first activated as a formation during the First World War on 7 November 1918, at Chaumont, France , when

636-559: A geocentric origin and the Geodetic Reference System 1980 ([[GRS   80]]). "This datum, designated as NAD   83…is based on the adjustment of 250,000 points including 600 satellite Doppler stations which constrain the system to a geocentric origin." NAD   83 may be considered a local referencing system. WGS   84 is the World Geodetic System of 1984. It is the reference frame used by

742-528: A global reference frame (such as WGS 84 ) is used, the coordinates of a place on the surface generally will change from year to year. Most mapping, such as within a single country, does not span plates. To minimize coordinate changes for that case, a different reference frame can be used, one whose coordinates are fixed to that particular plate. Examples of these reference frames are " NAD 83 " for North America and " ETRS89 " for Europe. United States Army Central The United States Army Central , formerly

848-559: A major training exercise in Egypt, "BRIGHT STAR 95," involving military forces from 6 other nations. This contingency operation validated critical procedures for deployment, particularly the off-loading of equipment from floating prepositioning ships and its distribution to arriving soldiers. The deployment of a "Fly-Away Package" of key contingency staff also validated procedures for a rapidly deployed command and control group able to conduct combat operations immediately upon arrival. The operation

954-463: A more accurate representation of some specific area of coverage than WGS   84 can. OSGB36 , for example, is a better approximation to the geoid covering the British Isles than the global WGS   84 ellipsoid. However, as the benefits of a global system outweigh the greater accuracy, the global WGS   84 datum has become widely adopted. The spherical nature of Earth was known by

1060-563: A period of consolidation, Third Army was ready to go on the offensive again. However, the Germans then launched their last great offensive of the war – the Battle of the Bulge . This battle was an attempt to repeat the decisive breakthrough of 1940 . However, in 1944, the Germans were doomed to failure. Their own logistical problems surfaced, and they ground to a halt. Nevertheless, they had broken

1166-595: A permanent Coalition/ Joint Task Force (C/JTF), headquartered at Camp Doha, Kuwait, and commanded by Lieutenant General Tommy R. Franks, Commanding General, Third Army/ARCENT. In addition to the U.S. and coalition forces already in Kuwait, a brigade task force from 3d Infantry Division, Fort Stewart, Georgia, rapidly deployed to Kuwait. Departing from Hunter Army Airfield, the brigade task force deployed 4,000 personnel and 2,900 short tons of equipment on 120 aircraft. Within 15 hours of landing at Kuwait City International Airport,

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1272-523: A pontoon bridge and three railroad bridges across the Rhine, had been established. Third Army troops had encountered no hostile act of any sort. In the occupied area, both food and coal supplies were sufficient. The crossing of the Rhine by the front line divisions was effected in good time and without confusion. Troops, upon crossing the Rhine and reaching their assigned areas, were billeted preparatory to occupying selected positions for defense. The strength of

1378-657: A series of physically monumented geodetic control points of known location. Global datums, such as WGS 84 and ITRF , are typically bound to the center of mass of the Earth (making them useful for tracking satellite orbits and thus for use in satellite navigation systems. A specific point can have substantially different coordinates, depending on the datum used to make the measurement. For example, coordinates in NAD   83 can differ from NAD   27 by up to several hundred feet. There are hundreds of local horizontal datums around

1484-409: A special ceremony was held at Fort McPherson to mark the return to Active Army status of Headquarters, Third U.S. Army under the command of Lieutenant General M. Collier Ross . Guests at the event included former Third Army Commanders, General (Retired) Herbert B. Powell and Lieutenant General (Retired) Louis W. Truman . The new headquarters was established at Fort McPherson , and its new mission

1590-447: A system known as photogrammetric positioning . By tying aerial photographs to base maps , artillery surveyors could readily obtain azimuth and location of firing positions. Working with the photographs and overprint of a map, aerial observers could give accurate references to targets. Tests proved favorable, and a system was in place after Operation Cedar Falls ." The Army Map Service Special Foreign Activities are carried out by

1696-512: A total of 1,811,388 in enemy losses. Fuller's review of Third Army records differs only in the number of enemy killed and wounded, stating that between 1 August 1944 and 9 May 1945, 47,500 of the enemy were killed, 115,700 wounded, and 1,280,688 captured. Fuller's combined total of enemy losses is 1,443,888 enemy killed, wounded, or captured by the Third Army. The Third Army suffered 16,596 killed, 96,241 wounded, and 26,809 missing in action for

1802-538: A total of 10 million copies. The Normandy invasion required 3,000 different maps with a total of 70 million copies. Similar commitments were filled for the Pacific and Far East operations. Maps of all types were needed, from the strategic level maps to tactical level maps. "Indeed, General George S. Patton claims to have planned Third Army movements by using a Michelin tourist road map of Europe, his knowledge of terrain, and gut-level feeling that tanks could negotiate

1908-404: A total of 139,646 casualties according to the aforementioned After Action Report of May 1945. According to Fuller, the Third Army lost 27,104 killed and 86,267 wounded. There were 18,957 injuries of all kinds and 28,237 men listed as missing in action. Including 127 men captured by the enemy, total casualties of the Third Army were 160,692 in 281 continuous days of operations. Fuller points out that

2014-484: A traditional standard horizontal or vertical datum. A standard datum specification (whether horizontal, vertical, or 3D) consists of several parts: a model for Earth's shape and dimensions, such as a reference ellipsoid or a geoid ; an origin at which the ellipsoid/geoid is tied to a known (often monumented) location on or inside Earth (not necessarily at 0 latitude 0 longitude); and multiple control points or reference points that have been precisely measured from

2120-564: Is "the horizontal control datum for the United States that was defined by a location and azimuth on the Clarke spheroid of 1866, with origin at (the survey station) Meades Ranch (Kansas) ." ... The geoidal height at Meades Ranch was assumed to be zero, as sufficient gravity data was not available, and this was needed to relate surface measurements to the datum. "Geodetic positions on the North American Datum of 1927 were derived from

2226-499: Is a model used to precisely measure positions on Earth; it is thus a crucial component of any spatial reference system or map projection . A horizontal datum binds a specified reference ellipsoid , a mathematical model of the shape of the earth, to the physical earth. Thus, the geographic coordinate system on that ellipsoid can be used to measure the latitude and longitude of real-world locations. Regional horizontal datums, such as NAD 27 and NAD 83 , usually create this binding with

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2332-512: Is completely parameterised by the semi-major axis a {\displaystyle a} and the flattening f {\displaystyle f} . From a {\displaystyle a} and f {\displaystyle f} it is possible to derive the semi-minor axis b {\displaystyle b} , first eccentricity e {\displaystyle e} and second eccentricity e ′ {\displaystyle e'} of

2438-571: Is the only world referencing system in place today. WGS   84 is the default standard datum for coordinates stored in recreational and commercial GPS units. Users of GPS are cautioned that they must always check the datum of the maps they are using. To correctly enter, display, and to store map related map coordinates, the datum of the map must be entered into the GPS map datum field. Examples of map datums are: The Earth's tectonic plates move relative to one another in different directions at speeds on

2544-536: Is used to measure a horizontal position , across the Earth 's surface, in latitude and longitude or another related coordinate system. A vertical datum is used to measure the elevation or depth relative to a standard origin, such as mean sea level (MSL). A three-dimensional datum enables the expression of both horizontal and vertical position components in a unified form. The concept can be generalized for other celestial bodies as in planetary datums . Since

2650-530: The Greenwich Observatory for longitude, from the Equator for latitude, or from the nearest coast for sea level. Astronomical and chronological methods have limited precision and accuracy, especially over long distances. Even GPS requires a predefined framework on which to base its measurements, so WGS   84 essentially functions as a datum, even though it is different in some particulars from

2756-711: The Anglo-French Survey (1784–1790) , by the end of the 18th century, survey control networks covered France and the United Kingdom . More ambitious undertakings such as the Struve Geodetic Arc across Eastern Europe (1816-1855) and the Great Trigonometrical Survey of India (1802-1871) took much longer, but resulted in more accurate estimations of the shape of the Earth ellipsoid . The first triangulation across

2862-755: The Central Map Reproduction Plant (CMRP). With the advent of World War I in 1917, the CMRP was re-organized and expanded by Major Charles H. Ruth in anticipation of a map supply crisis and was renamed the Engineer Reproduction Plant (EMP)." In 1910, the Map Reproduction Plant was given warehouse space at Ft. McNair , to accommodate the map reproduction unit of the Corps of Engineers. Ultimately named

2968-628: The Mauthausen-Gusen concentration camps complex. Its forces ended up in Czechoslovakia , the furthest east of any American units. The Third Army After Action of May 1945 states that the Third Army captured 765,483 prisoners of war, with an additional 515,205 of the enemy already held in corps and divisional level POW camps processed between 9 May and 13 May 1945, for a total of 1,280,688 POWs, and that, additionally, Third Army forces killed 144,500 enemy soldiers and wounded 386,200, for

3074-628: The Occupation of the Rhineland , for over three years. This was due, at least in part, to the fact that the United States, having rejected the Treaty of Versailles, was therefore still " de jure " at war with Germany. This situation remained unresolved until the summer of 1921 when a separate peace treaty was signed . On 15 October 1921, the Headquarters and Headquarters Company, Third Army,

3180-761: The Third United States Army , commonly referred to as the Third Army and as ARCENT , is a military formation of the United States Army that saw service in World War I and World War II , in the 1991 Gulf War , and in the coalition occupation of Iraq . It is best known for its campaigns in World War II under the command of General George S. Patton . The Third Army is headquartered at Shaw Air Force Base , South Carolina with

3286-1171: The U.S. Army Engineer Research and Development Laboratories (UASERDL) in 1947; then evolved into next into the Geodesy, Intelligence and Mapping Research and Development Agency (GIMRADA) in 1960; then the Engineer Topographic Laboratories (ETL) in 1967; and then became the Topographic Engineering Center (TEC), which came to be housed at the Humphreys Engineer Center in Alexandria, Virginia. TEC did research in such fields as terrain analysis and geospatial data generation; developed imagery exploitation, rapid prototyping, and other systems; and conducted operations in areas such as geospatial information, crisis support, urban studies, and historical photo environmental analysis. Reflecting TEC's growing responsibilities in more diverse and technologically sophisticated areas, its name

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3392-777: The U.S. Department of Defense (DoD) and is defined by the National Geospatial-Intelligence Agency (NGA) (formerly the Defense Mapping Agency, then the National Imagery and Mapping Agency). WGS   84 is used by the DoD for all its mapping, charting, surveying, and navigation needs, including its GPS "broadcast" and "precise" orbits. WGS   84 was defined in January 1987 using Doppler satellite surveying techniques. It

3498-450: The elevations of Earth features including terrain , bathymetry , water level , and human-made structures. An approximate definition of sea level is the datum WGS 84 , an ellipsoid , whereas a more accurate definition is Earth Gravitational Model 2008 (EGM2008), using at least 2,159 spherical harmonics . Other datums are defined for other areas or at other times; ED50 was defined in 1950 over Europe and differs from WGS   84 by

3604-459: The (coordinates of and an azimuth at Meades Ranch) through a readjustment of the triangulation of the entire network in which Laplace azimuths were introduced, and the Bowie method was used." NAD   27 is a local referencing system covering North America. The North American Datum of 1983 (NAD 83) is "The horizontal control datum for the United States, Canada, Mexico, and Central America, based on

3710-582: The 36th Parallel. When Saddam Hussein blocked United Nations weapons inspections, tested the resolve of coalition commitment by violating the no-fly zone, and publicly threatened to mimic earlier Soviet successes by shooting down U2 reconnaissance over-flights in the Fall of 1997, CENTCOM responded with a land, sea, and air strike force of more than 35,000 U.S. and coalition forces. In support of this powerful multi-service, multinational ground force, General Anthony C. Zinni, Commander-in-Chief, CENTCOM, established

3816-554: The 3d Infantry Division and the 32d Army Air and Missile Defense Command (AAMDC), personnel from the Theater Support Command (TSC), Air Support Operations Center (ASOC), and Marine forces. In addition, the redeployment of the Marine Expeditionary Unit (MEU) in the Persian Gulf was placed on hold and a second MEU was ordered to the Persian Gulf as reinforcement. While forces were deploying to

3922-543: The 64th Engineer Battalion (Base Topographic). Its assigned mission was to provide AMS with required geodetic, mapping control and field classification data which are used in the production of various scale topographic maps. The battalion operated in Libya, Iran , Ethiopia (including the Ethiopia – United States Mapping Mission ) and Liberia , and in some of the most rugged terrain in the world. Environmental conditions within

4028-506: The Allied Armies, submitted plans of operations to the Third Army commander to be used in the event that Germany should refuse to sign the peace treaty. On 20 May, Marshal Foch directed allied commanders to dispatch troops toward Weimar and Berlin in the event the peace treaty was not signed. On 22 May, the Third Army issued its plan of advance, effective 30 May, in view of the impending emergency. On 27 May, Foch informed Pershing that

4134-523: The Army area to facilitate command. In February, military schools were opened through the Third Army area; a quartermaster depot was organized; 2,000 officers and enlisted men left to take courses in British and French universities; better leave facilities were created; and plans for sending American divisions to the United States were made. On 4 February, the military control of the Stadtkreis of Trier

4240-564: The Central Map Reproduction Unit, it incorporated a lithographic school and 18 assigned military personnel. After World War I, this would be renamed the Engineer Reproduction Plant. The ERP was noted for experimentation on cartographic and photolithographic processes and media. They also experimentation in aerial photogrammetry . A number of US Geological Survey employees were assigned to

4346-771: The General Headquarters of the American Expeditionary Forces (AEF) issued General Order 198 organizing the Third Army and announcing its headquarters staff. On the 15th, four days after the Armistice with Germany , Major General Joseph T. Dickman assumed command and issued Third Army General Order No. 1. The Third Army consisted of three corps ( III Corps , Major General John L. Hines ; IV Corps , Major General Charles Henry Muir ; and VII Corps , Major General William G. Haan ) and seven divisions. On 15 November 1918, Major General Dickman

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4452-767: The Headquarters Company was not activated until 23 November 1940. The responsibility of the Third Army was overseeing the training and mobilization plans of its assigned units, and developing contingency defense plans for the Southern United States . As a result of mobilization, the Third Army took on the role of training some of the huge numbers of recruits that the draft was bringing into the United States Armed Forces . Lieutenant General Walter Krueger , later to gain fame for his command of Sixth Army during operations in

4558-482: The Pacific, commanded Third Army from May 1941 until February 1943. Under his leadership, the basis of the Army's later success as a combat formation was laid. Krueger was succeeded by Lieutenant General Courtney Hodges who led the Army for the rest of 1943. The news that many had expected came in December 1943 and the Third Army was shipped from the United States to the United Kingdom. Third Army did not take part in

4664-519: The Persian Gulf region, United Nations Secretary-General Kofi Annan flew to Baghdad to meet with Saddam Hussein. Following negotiations, Saddam Hussein agreed to allow uninterrupted resumption of United Nations weapons inspections. In mid-Nov, as the crisis defused, there were 2,300 personnel deployed to Kuwait in support of C/JTF-Kuwait. When Iraqi aircraft began challenging the established no-fly zones, and Iraqi air defense systems fired on allied aircraft in December 1998, US and UK forces responded with

4770-649: The Saudi oil fields. Since Saudi Arabia came within the CENTCOM area, Third Army was sent to command the Army units in theatre. At first, XVIII Corps made up the forces assigned to Third Army; enough men to ensure that the Iraqis could not invade Saudi Arabia. However, in November 1990, massive reinforcements were announced in the form of VII Corps from Germany. This deployment marked the largest use of armored formations by

4876-478: The Supreme War Council desired allied armies be made ready immediately to resume active operations against the Germans. On 1 June, the advance GHQ, AEF, at Trier was discontinued. On 16 June, Foch notified Pershing that allied armies must be ready after 20 June to resume offensive operations and that preliminary movements were to begin 17 June. On 19 June, Pershing notified Foch that beginning 23 June

4982-523: The Third Army as of 19 December, the date the bridgehead occupation was completed, was 9,638 officers and 221,070 enlisted men. On 12 December, Field Order No. 11 issued, directed the Third Army to occupy the northern sector of the Coblenz bridgehead, with the advance elements to cross the Rhine river at seven o'clock, 13 December. The northern (left) boundary remained unchanged. The southern (right) boundary

5088-464: The Third Army would occupy the towns of Limburg, Westerburg, Hachenburg, and Altenkirchen, and that III Corps would seize the railroad connecting these towns. On 23 June, the Germans signified their intention to sign the peace treaty and contemplated operations were suspended. On 30 June, Foch and Pershing conferred about the American troops to be left on the Rhine. On 1 July, General Pershing notified

5194-469: The U.S. front, and it took a great effort to reduce the resulting salient . In one of the great moves of the war, Patton heeded the advice of his Intelligence Officer, Oscar Koch , and planned to aid First Army if required. When the German offensive commenced, Patton was prepared to turn Third Army's axis of advance ninety degrees and advance north to the southern flank of the German forces. The German salient

5300-454: The U.S. since World War II, and thus it was fitting that Patton's old command, Third Army, should have control of the battle. By the opening of hostilities, XVIII Corps had three American and one French division and VII Corps four American and one British division under command, thus giving Third Army a total of nine divisions, plus the armored cavalry regiments attached to both corps. Third Army, commanded by Lieutenant General John J. Yeosock ,

5406-656: The US Army Corps of Engineers 29th Engineers, a map organization, during World War I. Major G.S. Smith commanded part of the 29th Engineers, a map making and topographical unit, with 53 officers and 146 men transferred from the US Geological Survey. Thirteen additional USGS topographers were assigned to the United States Army Coast Artillery Corps as "orienteur officers." When the 2nd Brigade of Coast Artillery

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5512-682: The US Army Signal Corps and US Navy to obtain astronomic, geodetic and gravimetric observations to determine the size and shape of the earth, intercontinental relationships and gravity fields. Continuing this work, Alden Colvocoresses developed the Space-oblique Mercator projection , which was used with the Landsat satellite to make the first satellite produced map of the US. The AMS and other agencies, split off to form

5618-573: The USACE determined the earth's size and shape, and included precise geodetic and astronomic surveys in many remote areas of the Pacific, the Arctic, Asia and South America. Work by Dr. Irene Fischer helped determine the parallax of the moon, and her geoid studies helped in investigation the lingering effects of the last ice age . The Corps of Engineers participated in the Vanguard satellite program with

5724-563: The United States was not completed until 1899. The U.S. survey resulted in the North American Datum (horizontal) of 1927 (NAD   27) and the Vertical Datum of 1929 (NAVD29), the first standard datums available for public use. This was followed by the release of national and regional datums over the next several decades. Improving measurements, including the use of early satellites , enabled more accurate datums in

5830-401: The United States. The Korean War saw a repeat of the earlier World War II training duties. The Third Army remained responsible for this aspect of U.S. Armed Forces operations until 1974, when a new major headquarters, that of Forces Command, or FORSCOM was activated to replace Third Army. Third Army was thus inactivated, and it remained so for the better part of a decade. On 3 December 1982,

5936-643: The War Department that upon Germany's compliance with military conditions imposed upon her (probably within three months after German ratification of the treaty), the American forces in Europe would be reduced to a single regiment of infantry supplemented by necessary auxiliaries. Accordingly, the Third Army was disbanded on 2 July 1919. Its headquarters and all personnel (numbering about 6,800 men) and units under it were thereafter designated American Forces in Germany. This force would remain in Germany, as part of

6042-465: The ancient Greeks, who also developed the concepts of latitude and longitude, and the first astronomical methods for measuring them. These methods, preserved and further developed by Muslim and Indian astronomers, were sufficient for the global explorations of the 15th and 16th Centuries. However, the scientific advances of the Age of Enlightenment brought a recognition of errors in these measurements, and

6148-463: The areas of operation created physical hazards such as miles of desert, blinding sand storms that imperil health and damage delicate instruments, mountains that range up to 15,000 feet above sea level, and steaming jungles with wild animals, dangerous reptiles and insects. These were routine field conditions for the men of the 64th. During the early years of the Space Age , geodetic investigations by

6254-436: The artillery to ensure the accuracy of fire, but as artillery units moved to more remote areas it became more difficult to support friendly units because surveys were lacking. In early 1967, Lt. Col. Arthur L. Benton , the former chief of the Mapping and Intelligence Section of the Engineer Sections, United States Army Vietnam , who had returned to Vietnam on temporary duty from the Army Map Service in Washington, D.C., developed

6360-439: The cease fire. In October 1994, ARCENT was again called upon to command, control, and deploy U.S. Army forces to Kuwait during Operation Vigilant Warrior. The operation was initiated in response to Saddam Hussein's saber rattling and posturing of Iraqi military forces along the Iraqi-Kuwaiti border. This act of aggression threatened to upset the delicate balance of peace in the region. ARCENT's rapid generation and deployment of

6466-439: The conclusion of the Persian Gulf War. According to the Third Army, the demonstrated capability to quickly deploy combat forces from around the world deterred Iraqi aggression and helped reinstate compliance with the UN Weapons Inspection Program. In November 1998, when the work of the UN inspectors was again interrupted, Third Army quickly returned to the Persian Gulf to convince Saddam that the United States stood ready to enforce

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6572-422: The coordinates of a point from one datum system to another. Because the survey networks upon which datums were traditionally based are irregular, and the error in early surveys is not evenly distributed, datum conversion cannot be performed using a simple parametric function. For example, converting from NAD 27 to NAD 83 is performed using NADCON (later improved as HARN), a raster grid covering North America, with

6678-400: The crisis, the 22nd Support Command served as the primary Logistics and Combat Service Support organization for ARCENT during the Operation Desert Shield , Operation Desert Storm and Operation Desert Farewell portions of the operation. The Command was activated as the ARCENT SUPCOM (Provisional) on 19 August 1990, but had been in operation since 10 August 1990. The ARCENT SUPCOM (PROV)

6784-459: The datum used to make the measurement. There are hundreds of locally developed reference datums around the world, usually referenced to some convenient local reference point. Contemporary datums, based on increasingly accurate measurements of the shape of Earth, are intended to cover larger areas. The most common reference Datums in use in North America are NAD   27, NAD   83, and WGS 84 . The North American Datum of 1927 (NAD   27)

6890-408: The disparity on the ground between a point having the same horizontal coordinates in two different datums could reach kilometers if the point is far from the origin of one or both datums. This phenomenon is called datum shift or, more generally, datum transformation , as it may involve rotation and scaling, in addition to displacement. Because Earth is an imperfect ellipsoid, local datums can give

6996-827: The ellipsoid The two main reference ellipsoids used worldwide are the GRS   80 and the WGS   84. A more comprehensive list of geodetic systems can be found here . The Global Positioning System (GPS) uses the World Geodetic System 1984 (WGS   84) to determine the location of a point near the surface of Earth. The difference in co-ordinates between datums is commonly referred to as datum shift . The datum shift between two particular datums can vary from one place to another within one country or region, and can be anything from zero to hundreds of meters (or several kilometers for some remote islands). The North Pole , South Pole and Equator will be in different positions on different datums, so True North will be slightly different. Different datums use different interpolations for

7102-470: The exodus of American divisions from Third Army to the United States began. During the month, motor transport parks were established; an Army motor show was held; the Army area was reorganized; and the centralization of military property was initiated in anticipation of returning it to the United States. On 20 April 1919, Third Army command changed from Maj. Gen. Dickman to Lt. Gen. Hunter Liggett . On 14 May 1919, Marshal Ferdinand Foch , General-in-Chief of

7208-447: The first four weeks of the conflict, the Far East Command printed and distributed 10 million maps. In 1954, the 29th Engineer Topographic Battalion assumed responsibility for Korea and Okinawa and moved to Tokyo , Japan. There it absorbed the 64th Engineer Battalion and continued its mission of providing topographic support to U.S. and Allied forces in the Pacific Theatre, particularly to combat commands in Southeast Asia. In May 1966,

7314-400: The ground William the Conqueror had crossed nine centuries before." The Corps of Engineers mapping output differs from general mapping agencies, such as the USGS, in that it is usually at a much larger scale (design/construction) and is project-specific; however, the mapping procedures used since World War II are not much different. Between 1949 and 1951, standardization of military mapping

7420-442: The ground was equipment for two more brigades (one Army and one Marine) afloat in the Persian Gulf with the Maritime Preposition Force. These ships were poised to link up with soldiers and Marines who would draw their equipment and begin combat operations if required. Attack air provided by Navy, Air Force, and Coalition assets rounded out this formidable force. This was the largest multinational force assembled in Southwest Asia since

7526-424: The initial stages of Operation Overlord . However, when it did take the field, it was led by George S. Patton . When Third Army was moved to France, it was just after formations under the command of Omar Bradley had achieved the breakout from Normandy . Third Army followed up on that success and began a great dash across France, ultimately out-running its supply lines which halted it near the German border. After

7632-725: The later 20th century, such as NAD 83 in North America, ETRS89 in Europe, and GDA94 in Australia. At this time global datums were also first developed for use in satellite navigation systems, especially the World Geodetic System (WGS   84) used in the U.S. global positioning system (GPS), and the International Terrestrial Reference System and Frame (ITRF) used in the European Galileo system. A horizontal datum

7738-610: The logistic military planning of Corps of Engineer items. Another major responsibility of the AMS was to maintain the largest geodetic and topographic data libraries for the Department of Defense. "The Army Map Service had its inception in a warehouse located at Ft. McNair (formerly the Army War College ), where space was set aside in 1910 to accommodate a reproduction unit and lithographic school. The combined elements formed

7844-470: The occupied area both food and coal supplies were sufficient. By the night of 14 December, Third Army troops had occupied their positions on the perimeter of the Coblenz bridgehead. During January 1919, the Third Army was engaged in training and preparing the troops under its command for any contingency. A letter of instruction was circulated to lower commanders prescribing a plan of action in case hostilities were resumed. Installations were set up throughout

7950-667: The order of 50 to 100 mm (2.0 to 3.9 in) per year. Therefore, locations on different plates are in motion relative to one another. For example, the longitudinal difference between a point on the equator in Uganda, on the African Plate , and a point on the equator in Ecuador, on the South American Plate , increases by about 0.0014 arcseconds per year. These tectonic movements likewise affect latitude. If

8056-409: The origin and physically monumented. Then the coordinates of other places are measured from the nearest control point through surveying . Because the ellipsoid or geoid differs between datums, along with their origins and orientation in space, the relationship between coordinates referred to one datum and coordinates referred to another datum is undefined and can only be approximated. Using local datums,

8162-636: The outbreak of the operations in the Vietnam War in December 1966, the Army Map Service printed and shipped more than 200 million maps. " Mapmaking provided another area for engineer innovation in Vietnam. Up to date map and topographic information were key ingredients to military operations in Vietnam, especially the placement of artillery fire. During the early stages of the war, artillery units normally supported ground units from fixed positions into which ground control had been extended. Surveys enabled

8268-598: The pontoon bridge and railroad bridge at Coblenz, the railroad bridges at Engers and Remagen . On 13 December the advance began with the American khaki crossing the Rhine into advanced positions. On the same day the 42d Division passed to the command of the IV Corps , which, in support of the III Corps, continued its march to occupy the Kreise of Mayen , Ahrweiler , Adenau , and Cochem . The VII Corps occupied under

8374-520: The precise shape and size of Earth ( reference ellipsoids ). For example, in Sydney there is a 200 metres (700 feet) difference between GPS coordinates configured in GDA (based on global standard WGS   84) and AGD (used for most local maps), which is an unacceptably large error for some applications, such as surveying or site location for scuba diving . Datum conversion is the process of converting

8480-465: The ratio of German troop deaths to American deaths in the Third Army operating area was 1.75:1. In the immediate postwar occupation, Army G-2 briefly hosted the Fedden Mission . Third Army remained in Germany until recalled to the United States again in 1947. When back in the United States, its duties were much the same as those of the 1930s, acting as a command and training force for units in

8586-468: The rise of the global positioning system (GPS), the ellipsoid and datum WGS 84 it uses has supplanted most others in many applications. The WGS   84 is intended for global use, unlike most earlier datums. Before GPS, there was no precise way to measure the position of a location that was far from reference points used in the realization of local datums, such as from the Prime Meridian at

8692-562: The same order that portion of the Regierungsbezirk of Trier within army limits. On 15 December, Third Army Headquarters at Mayen opened at Coblenz: III Corps Headquarters at Polch opened at Neuwied and IV Corps Headquarters remained at Cochem, with the VII Corps at Grevenmacher . In crossing the Rhine on the shortened front—from Rolandseck to Rhens on the west bank—the Third Army encountered no hostile act of any sort. In

8798-431: The terms of the cease-fire. As Saddam Hussein violated United Nations sanctions and threatened regional stability, the United States began deploying to Kuwait and preparing for combat operations. Combined/Joint Task Force-Kuwait, in place since Desert Thunder I, played a key role in the rapid deployment, reception, staging, onward movement, and integration of forces. Units deploying to Kuwait included advance parties from

8904-831: The unit (less its survey element) moved to Ford Island , Hawaii, and was the primary map production unit for U.S. Forces in Vietnam. In January 1969, the unit was awarded the Meritorious Unit Commendation by the CINC, U.S. Army Pacific. A second Meritorious Unit Commendation was awarded in 1972. The Corps of Engineers also participated in the Inter-American Geodetic Survey for mapping Central and South America. As part of this research many poorer nations could develop their resources. "In Cuba , for instance, an extensive water table survey by IAGS made it possible to develop 500 wells." From

9010-609: The unit had drawn prepositioned equipment and was in battle positions in the desert. On 28 February, Combined Joint Task Force Kuwait (C/JTF-K) was prepared to defend Kuwait with a ground force strength of more than 9,000 personnel. Argentina, Australia, Canada, Czech Republic, Hungary, New Zealand, Poland, Romania, the United Kingdom, and Kuwait rounded out the C/JTF by providing liaison teams, aircraft support, special operations elements, chemical/biological defense, base defense units, MASH units, and medical personnel. Added to forces on

9116-470: The value of each cell being the average adjustment distance for that area in latitude and longitude. Datum conversion may frequently be accompanied by a change of map projection . A geodetic reference datum is a known and constant surface which is used to describe the location of unknown points on Earth. Since reference datums can have different radii and different center points, a specific point on Earth can have substantially different coordinates depending on

9222-464: The war, considerable effort was being applied to large scale mapping by stereo-photogrammetric methods. Between 1941 and 1945, the Army Map Service prepared 40,000 maps of all types, covering 400,000 square miles of the Earth's surface. Over 500 million copies were produced during the war. Many were produced by civilian women trained after Pearl Harbor, the " Military Mapping Maidens ." The North African Campaign alone required 1,000 different maps with

9328-531: The world, usually referenced to some convenient local reference point. Contemporary datums, based on increasingly accurate measurements of the shape of Earth, are intended to cover larger areas. The WGS 84 datum, which is almost identical to the NAD 83 datum used in North America and the ETRS89 datum used in Europe, is a common standard datum. A vertical datum is a reference surface for vertical positions , such as

9434-421: Was prolate (wider at the poles). The subsequent French geodesic missions (1735-1739) to Lapland and Peru corroborated Newton, but also discovered variations in gravity that would eventually lead to the geoid model. A contemporary development was the use of the trigonometric survey to accurately measure distance and location over great distances. Starting with the surveys of Jacques Cassini (1718) and

9540-557: Was agreed to between Canada , Great Britain and the US, and was expanded to NATO , SEATO and CENTO countries as well. This involved the application of the UTM to over 10,000 different maps covering 400,000 square miles and the printing of over 90,000,000 copies. The Army Map Service distributed 750,000 maps to all services during the first two weeks of the Korean War . In the following two weeks five million maps were printed, while in

9646-402: Was as has been previously mentioned. Before the advance, the 1st Division passed to the command of the III Corps. With three divisions, the 1st, 2d, and 32d, the III Corps occupied the American sector of the Coblenz bridgehead, the movement of the troops into position beginning at the scheduled hour, 13 December. The four bridges available for crossing the river within the Coblenz bridgehead were

9752-839: Was changed to the Army Geospatial Center in 2009. It continues to support both military and civil works activities. Geodetic system A geodetic datum or geodetic system (also: geodetic reference datum , geodetic reference system , or geodetic reference frame , or terrestrial reference frame ) is a global datum reference or reference frame for unambiguously representing the position of locations on Earth by means of either geodetic coordinates (and related vertical coordinates ) or geocentric coordinates . Datums are crucial to any technology or technique based on spatial location, including geodesy , navigation , surveying , geographic information systems , remote sensing , and cartography . A horizontal datum

9858-622: Was constituted in the Organized Reserve as one of six field armies to control the units of the U.S. Army that were stationed on home soil. The Headquarters was initiated on 25 February 1922 in Omaha, Nebraska , while the Headquarters Company was initiated in April 1924 in St. Louis, Missouri ; the Headquarters Company was concurrently relocated to Omaha. On 18 August 1933, the Headquarters Company

9964-572: Was deployed to Kuwait under the command of Third Army/ARCENT as follow on forces to an already deployed Task Force (Task Force Headhunter, 1/9th and 1/12th Cavalry) to deter potential retaliatory attacks on Kuwait. The Brigade Task Force was supported by elements of the United States Marines, British Royal Marines and the Kuwaiti Liberation Brigade. Hussein soon capitulated, withdrawing his military forces south of

10070-604: Was described by Third Army as having convinced Hussein to withdraw his forces from the Kuwaiti border. In September 1996, it was alleged that Iraq violated United Nations sanctions by deploying forces north of the 36th Parallel and attacking ethnic Kurds in Northern Iraq. In response to Hussein's refusal to withdraw his forces, the U.S. launched cruise missile strikes against selected military targets inside Iraq. A heavy brigade task force, 2nd Brigade, 1st Cavalry Division,

10176-613: Was formed during World War II from the consolidation of the Engineer Reproduction Plant, the Library and the Cartographic Section of the War Department General Staff . Initially, many of the maps produced were revisions of existing maps. By the middle of the war, the cartographic work was changed to medium and small scale maps utilizing larger scale native maps as source materials. By the end of

10282-547: Was formed, the military made a similar request for more USGS personnel, but the order was denied as these men were needed for the US Army Corps of Engineers. After World War I, the 29th Engineer (Topo) Battalion performed the Nicaragua Canal Survey. It was at this time that Benjamin B. Talley , later a brigadier general, invented a portable stereocomparagraph for map making . The Army Map Service

10388-672: Was given the mission to move quickly and by any means into the Rhineland on occupation duties. He was to disarm and disband German forces as ordered by General John J. Pershing , commander of the AEF. The march into the Rhineland for occupation duty was begun on 17 November 1918. By 15 December the Third Army Headquarters at Mayen opened at Koblenz . Two days later, on 17 December 1918, the Koblenz bridgehead, consisting of

10494-412: Was redefined again and was more closely aligned with International Earth Rotation Service (IERS) frame ITRF 94. It was then formally called WGS   84 (G873). WGS   84 (G873) was adopted as the reference frame for broadcast orbits on January 29, 1997. Another update brought it to WGS   84 (G1674). The WGS   84 datum, within two meters of the NAD   83 datum used in North America,

10600-602: Was redesignated the 22nd Support Command on 16 December 1990. During the conflict, the commander was Major General, and then Lieutenant General William 'Gus' Pagonis . When the Command was disestablished following Operation Desert Farewell, it was succeeded by the 1st Area Support Group. Third Army/ARCENT remained engaged in the Middle East after the end of the Persian Gulf War with various operations to enforce

10706-486: Was reduced by the end of January 1945, and the remainder of the process of closing up to the Rhine could be completed. Some vicious fighting took place, but by April there was but one great natural barrier between Third Army and the heart of Germany. Unlike in 1918, the crossing of the Rhine was opposed. However, the bridgehead was won, and Third Army embarked on another great eastward dash. It reached Austria and in May liberated

10812-568: Was the main striking force in Operation Desert Storm . Its units were on the left flank of the attacking force and swept into southern Iraq. They then turned east and engaged the Iraqi Republican Guard in fierce combat. Much of that force was destroyed. In terms of its immediate aims, the Persian Gulf War was a stunning success. The Iraqis were ejected from Kuwait and their forces were thoroughly mauled. During

10918-696: Was to serve as the Army component in a unified command, the United States Central Command, which has responsibility over a vast overseas area covering parts of Africa, Asia, and the Persian Gulf. For its part, Third Army could draw upon a reservoir of Army units, and became responsible for planning, exercising, and rapidly deploying these units in crisis situations. It was not until 1990 that Third Army returned to combat. Saddam Hussein invaded Kuwait in August 1990, and American forces were immediately dispatched to Saudi Arabia to protect

11024-535: Was transferred from GHQ to the Third Army. In March, routine duties of occupation and training were carried on; an Army horse show was held; Army, corps, and divisional educational centers were established in the Third Army Zone; the Coblenz port commander took over the duties of the Coblenz regulating officer; and the 42d Division was released from IV Corps and was placed in Army Reserve. In April,

11130-448: Was used as the reference frame for broadcast GPS Ephemerides (orbits) beginning January 23, 1987. At 0000 GMT January 2, 1994, WGS   84 was upgraded in accuracy using GPS measurements. The formal name then became WGS   84 (G730), since the upgrade date coincided with the start of GPS Week 730. It became the reference frame for broadcast orbits on June 28, 1994. At 0000 GMT September 30, 1996 (the start of GPS Week 873), WGS   84

11236-691: Was withdrawn from the Organized Reserve and allotted to the Regular Army and the Headquarters was demobilized. In a reorganization of field forces in the United States, the Headquarters and Headquarters Company, Third Army, was reconstituted in the Regular Army as one of four field armies to control the units of the U.S. Army that were stationed on home soil. The Headquarters was organized on 15 September 1932 in Houston, Texas , although

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