The AGM-84E SLAM (Standoff Land Attack Missile) was a subsonic, over-the-horizon air-launched cruise missile that was developed by McDonnell Douglas from the AGM-84 Harpoon anti-ship missile . The SLAM was designed to provide all-weather, day and night, precision attack capabilities against stationary high-value targets as well as ships in port.
106-548: Except for new technologies in the guidance and seeker sections, which included a Global Positioning System receiver, a modified AGM-65F Maverick missile IIR Seeker, and a modified Walleye datalink , all of the missile hardware came directly from the Harpoon missile . SLAM missile uses an inertial navigation system , which is supplemented by Global Positioning System (GPS) input, and it also uses infrared homing terminal guidance. It could also be guided by any aircraft carrying
212-408: A moving map display , or recorded or used by some other system, such as a vehicle guidance system. Although usually not formed explicitly in the receiver processing, the conceptual time differences of arrival (TDOAs) define the measurement geometry. Each TDOA corresponds to a hyperboloid of revolution (see Multilateration ). The line connecting the two satellites involved (and its extensions) forms
318-705: A deliberate error introduced into the GPS data that military receivers could correct for. As civilian GPS usage grew, there was increasing pressure to remove this error. The SA system was temporarily disabled during the Gulf War , as a shortage of military GPS units meant that many US soldiers were using civilian GPS units sent from home. In the 1990s, Differential GPS systems from the US Coast Guard , Federal Aviation Administration , and similar agencies in other countries began to broadcast local GPS corrections, reducing
424-450: A directive making GPS freely available for civilian use, once it was sufficiently developed, as a common good. The first Block II satellite was launched on February 14, 1989, and the 24th satellite was launched in 1994. The GPS program cost at this point, not including the cost of the user equipment but including the costs of the satellite launches, has been estimated at US$ 5 billion (equivalent to $ 10 billion in 2023). Initially,
530-517: A full complement of 24 satellites in 2027. The GPS project was launched in the United States in 1973 to overcome the limitations of previous navigation systems, combining ideas from several predecessors, including classified engineering design studies from the 1960s. The U.S. Department of Defense developed the system, which originally used 24 satellites, for use by the United States military, and became fully operational in 1993. Civilian use
636-429: A liaison. The U.S. Department of Defense is required by law to "maintain a Standard Positioning Service (as defined in the federal radio navigation plan and the standard positioning service signal specification) that will be available on a continuous, worldwide basis" and "develop measures to prevent hostile use of GPS and its augmentations without unduly disrupting or degrading civilian uses". USA-203 from Block IIR-M
742-563: A manageable level to permit accurate navigation. During Labor Day weekend in 1973, a meeting of about twelve military officers at the Pentagon discussed the creation of a Defense Navigation Satellite System (DNSS) . It was at this meeting that the real synthesis that became GPS was created. Later that year, the DNSS program was named Navstar. Navstar is often erroneously considered an acronym for "NAVigation System using Timing And Ranging" but
848-464: A military defense force stagnated as they focused on other concerns relevant to setting up the new government. President George Washington went to Congress to remind them of their duty to establish a military twice during this time. Finally, on the last day of the session, September 29, 1789, Congress created the War Department . The War Department handled naval affairs until Congress created
954-461: A minimum, four satellites must be in view of the receiver for it to compute four unknown quantities (three position coordinates and the deviation of its own clock from satellite time). Each GPS satellite continually broadcasts a signal ( carrier wave with modulation ) that includes: Conceptually, the receiver measures the TOAs (according to its own clock) of four satellite signals. From the TOAs and
1060-431: A receiver start-up situation. Most receivers have a track algorithm , sometimes called a tracker , that combines sets of satellite measurements collected at different times—in effect, taking advantage of the fact that successive receiver positions are usually close to each other. After a set of measurements are processed, the tracker predicts the receiver location corresponding to the next set of satellite measurements. When
1166-564: A simulated SA-10 radar van in a target complex located on San Nicolas Island. In the year 2000, the SLAM was replaced in service by the AGM-84H SLAM-ER (Standoff Land Attack Missile Expanded Response), which had numerous new capabilities including increased target penetration and nearly twice the range of the older AGM-84E SLAM. Global Positioning System The Global Positioning System ( GPS ), originally Navstar GPS ,
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#17327728169251272-650: Is a satellite-based radio navigation system owned by the United States Space Force and operated by Mission Delta 31 . It is one of the global navigation satellite systems (GNSS) that provide geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. It does not require the user to transmit any data, and operates independently of any telephone or Internet reception, though these technologies can enhance
1378-610: Is not military, such as the Department of Homeland Security, counter-terrorism spending by the FBI, and intelligence-gathering spending by the NSA. In the 2010 United States federal budget , the Department of Defense was allocated a base budget of $ 533.7 billion, with a further $ 75.5 billion adjustment in respect of 2009, and $ 130 billion for overseas contingencies. The subsequent 2010 Department of Defense Financial Report shows
1484-527: Is owned and operated by the United States government as a national resource. The Department of Defense is the steward of GPS. The Interagency GPS Executive Board (IGEB) oversaw GPS policy matters from 1996 to 2004. After that, the National Space-Based Positioning, Navigation and Timing Executive Committee was established by presidential directive in 2004 to advise and coordinate federal departments and agencies on matters concerning
1590-540: Is the secretary and their deputies, including predominantly civilian staff. OSD is the principal staff element of the Secretary of Defense in the exercise of policy development, planning, resource management, fiscal and program evaluation and oversight, and interface and exchange with other U.S. federal government departments and agencies, foreign governments, and international organizations, through formal and informal processes. OSD also performs oversight and management of
1696-808: Is unhealthy For a more complete list, see List of GPS satellites On February 10, 1993, the National Aeronautic Association selected the GPS Team as winners of the 1992 Robert J. Collier Trophy , the US's most prestigious aviation award. This team combines researchers from the Naval Research Laboratory, the U.S. Air Force, the Aerospace Corporation , Rockwell International Corporation, and IBM Federal Systems Company. The citation honors them "for
1802-769: The Central Intelligence Agency , the National Security Council , National Security Resources Board , United States Air Force , and the Joint Chiefs of Staff . The act placed the National Military Establishment under the control of a single secretary of defense . The National Military Establishment formally began operations on September 18, the day after the Senate confirmed James V. Forrestal as
1908-503: The Doppler effect , they could pinpoint where the satellite was along its orbit. The Director of the APL gave them access to their UNIVAC I computer to perform the heavy calculations required. Early the next year, Frank McClure, the deputy director of the APL, asked Guier and Weiffenbach to investigate the inverse problem: pinpointing the user's location, given the satellite's. (At the time,
2014-970: The Eisenhower School (ES) and the National War College (NWC). Faced with rising tensions between the Thirteen Colonies and the British government , one of the first actions taken by the First Continental Congress in September 1774 was to recommend that the colonies begin defensive military preparations. In mid-June 1775, after the outbreak of the Revolutionary War , the Second Continental Congress , recognizing
2120-523: The Navy Department in 1798. The secretaries of each department reported directly to the president as cabinet-level advisors until 1949, when all military departments became subordinate to the Secretary of Defense. After the end of World War II , President Harry Truman proposed the creation of a unified department of national defense. In a special message to the Congress on December 19, 1945,
2226-674: The Office of the Director of National Intelligence . They fulfill the requirements of national policymakers and war planners, serve as Combat Support Agencies , and also assist and deploy alongside non-Department of Defense intelligence or law enforcement services such as the Central Intelligence Agency and the Federal Bureau of Investigation . The military services each have their intelligence elements that are distinct from but subject to coordination by national intelligence agencies under
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#17327728169252332-565: The Tigris River , specifically the power house and turbines. This plant was targeted because it powered the Al-Qa'im superphosphate fertilizer plant (nicknamed 'Big Al'), known to produce yellowcake for uranium enrichment. The SLAMs were guided by an A-7E Corsair II from VA-72 (also from the Kennedy ) via the use of a Datalink pod. Although GPS guidance could have done the job without
2438-494: The USS John F. Kennedy (CV-67) , were before official operational testing of the new missile had begun. Only five SLAMs were carried to the war, all on the Kennedy . They had also been only been recently moved to carrier. The first time the SLAM was used in combat came on January 18, 1991, when two SLAMs, fired two minutes apart, were launched by an A-6E SWIP Intruder from VA-75 towards a Hydro-electric plant north of Baghdad on
2544-703: The deputy secretary of defense . Secretaries of military departments, in turn, normally exercise authority over their forces by delegation through their respective service chiefs (i.e., Chief of Staff of the Army , Commandant of the Marine Corps , Chief of Naval Operations , Chief of Staff of the Air Force , and Chief of Space Operations ) over forces not assigned to a Combatant Command . Secretaries of Military Departments and service chiefs do not possess operational command authority over U.S. troops (this power
2650-470: The fiscal year 2024 (FY2024) presidential budget request was $ 842 billion. In January 2023 Treasury Secretary Janet Yellen announced the US government would hit its $ 31.4 trillion debt ceiling on 19 January 2023; the date on which the US government would no longer be able to use extraordinary measures such as issuance of Treasury securities is estimated to be in June 2023. On 3 June 2023,
2756-504: The navigation equations gives the position of the receiver along with the difference between the time kept by the receiver's on-board clock and the true time-of-day, thereby eliminating the need for a more precise and possibly impractical receiver based clock. Applications for GPS such as time transfer , traffic signal timing, and synchronization of cell phone base stations , make use of this cheap and highly accurate timing. Some GPS applications use this time for display, or, other than for
2862-535: The AN/AWW-9B and AN/AWW-13 datalink pods. The missile however was unable to avoid terrain, meaning that to attack a target, there had to be no obstacles in the path of the missile. Developed in 48 months, three SLAMs were successfully employed during the Persian Gulf War , when they were used to strike Iraqi targets. These strikes, made exclusively by the few A-6E SWIP Intruders assigned to VA-75 on
2968-646: The Army , Secretary of the Navy and Secretary of the Air Force ), appointed by the president, with the advice and consent of the Senate . They have the legal authority under Title 10 of the United States Code to conduct all the affairs of their respective departments within which the military services are organized. The secretaries of the Military Departments are (by law) subordinate to the secretary of defense and (by SecDef delegation) to
3074-603: The CIA's human intelligence efforts while also focusing on military human intelligence priorities. These agencies are directly overseen by the Under Secretary of Defense for Intelligence and Security . The Joint Chiefs of Staff (JCS) is a body of senior uniformed leaders in the Department of Defense who advise the secretary of defense, the Homeland Security Council , the National Security Council and
3180-796: The Chairman of the Joint Chiefs of Staff (CJCS) as the "principal military adviser to the President, the National Security Council, the Homeland Security Council, and the Secretary of Defense". The remaining Joint Chiefs of Staff may only have their advice relayed to the President, National Security Council, the Homeland Security Council , or the Secretary of Defense after submitting it to the CJCS. By law,
3286-562: The Defense Agencies, Department of Defense Field Activities, and specialized Cross Functional Teams . OSD is a parent agency of the following defense agencies: Several defense agencies are members of the United States Intelligence Community . These are national-level intelligence services that operate under the Department of Defense jurisdiction but simultaneously fall under the authorities of
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3392-523: The Department of Defense budget, such as nuclear weapons research, maintenance, cleanup, and production, which is in the Department of Energy budget, Veterans Affairs, the Treasury Department's payments in pensions to military retirees and widows and their families, interest on debt incurred in past wars, or State Department financing of foreign arms sales and militarily-related development assistance. Neither does it include defense spending that
3498-474: The Department of Defense. Department of Defense manages the nation's coordinating authorities and assets in disciplines of signals intelligence , geospatial intelligence , and measurement and signature intelligence , and also builds, launches, and operates the Intelligence Community's satellite assets. Department of Defense also has its own human intelligence service , which contributes to
3604-524: The Earth's center) and the offset of the receiver clock relative to the GPS time are computed simultaneously, using the navigation equations to process the TOFs. The receiver's Earth-centered solution location is usually converted to latitude , longitude and height relative to an ellipsoidal Earth model. The height may then be further converted to height relative to the geoid , which is essentially mean sea level. These coordinates may be displayed, such as on
3710-600: The FY 2019 budget: "The overall number you often hear is $ 716 billion. That is the amount of funding for national defense, the accounting code is 050 and includes more than simply the Department of Defense. It includes, for example, the Department of Energy and others. That large a number, if you back out the $ 30 billion for non-defense agencies, you get to $ 686 billion. That is the funding for the Department of Defense, split between $ 617 billion in base and $ 69 billion in overseas contingency ". The Department of Defense budget encompasses
3816-520: The FY2018 Budget expired and the FY2019 budget came into effect. The FY2019 Budget for the Department of Defense is approximately $ 686,074,048,000 (Including Base + Overseas Contingency Operations + Emergency Funds) in discretionary spending and $ 8,992,000,000 in mandatory spending totaling $ 695,066,000,000 Undersecretary of Defense (Comptroller) David L. Norquist said in a hearing regarding
3922-604: The GPS and related systems. The executive committee is chaired jointly by the Deputy Secretaries of Defense and Transportation. Its membership includes equivalent-level officials from the Departments of State, Commerce, and Homeland Security, the Joint Chiefs of Staff and NASA . Components of the executive office of the president participate as observers to the executive committee, and the FCC chairman participates as
4028-668: The GPS service, including new signals for civil use and increased accuracy and integrity for all users, all the while maintaining compatibility with existing GPS equipment. Modernization of the satellite system has been an ongoing initiative by the U.S. Department of Defense through a series of satellite acquisitions to meet the growing needs of the military, civilians, and the commercial market. As of early 2015, high-quality Standard Positioning Service (SPS) GPS receivers provided horizontal accuracy of better than 3.5 meters (11 ft), although many factors such as receiver and antenna quality and atmospheric issues can affect this accuracy. GPS
4134-740: The Global Positioning System (GPS) its 60th Anniversary Award, nominated by IAF member, the American Institute for Aeronautics and Astronautics (AIAA). The IAF Honors and Awards Committee recognized the uniqueness of the GPS program and the exemplary role it has played in building international collaboration for the benefit of humanity. On December 6, 2018, Gladys West was inducted into the Air Force Space and Missile Pioneers Hall of Fame in recognition of her work on an extremely accurate geodetic Earth model, which
4240-812: The Joint Chiefs of Staff ( JCS ) and the Joint Staff ( JS ), Office of the Inspector General ( DODIG ), the Combatant Commands , the Military Departments ( Department of the Army (DA), Department of the Navy (DON) & Department of the Air Force (DAF)), the Defense Agencies and Department of Defense Field Activities , the National Guard Bureau (NGB), and such other offices, agencies, activities, organizations, and commands established or designated by law, or by
4346-655: The Missile Engagement Zone of Al-Qa'im. Several months after the Gulf War, the SLAM was officially approved for full production on June 28, 1991. The SLAM was also used during United Nations air raids in Bosnia during operations Deny Fly (1993-1995) and Deliberate Force (1995). An F/A-18C (N) Hornet from VFA-151 ^ in February 1999 tested the SLAM's special GPS only guidance mode against
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4452-588: The NDAA on 14 December 2023. The Senate will next undertake negotiations on supplemental spending for 2024. A government shutdown was averted on 23 March 2024 with the signing of a $ 1.2 trillion bill to cover FY2024. A 2013 Reuters investigation concluded that Defense Finance & Accounting Service , the Department of Defense's primary financial management arm, implements monthly "unsubstantiated change actions"—illegal, inaccurate "plugs"—that forcibly make DoD's books match Treasury's books. Reuters reported that
4558-1106: The National Security Agency ( NSA ), the National Geospatial-Intelligence Agency ( NGA ), and the National Reconnaissance Office ( NRO ). Other Defense agencies include the Defense Advanced Research Projects Agency ( DARPA ), the Defense Logistics Agency ( DLA ), the Missile Defense Agency ( MDA ), the Defense Health Agency ( DHA ), Defense Threat Reduction Agency ( DTRA ), the Defense Counterintelligence and Security Agency ( DCSA ),
4664-480: The Navy TRANSIT system were too slow for the high speeds of Air Force operation. The Naval Research Laboratory (NRL) continued making advances with their Timation (Time Navigation) satellites, first launched in 1967, second launched in 1969, with the third in 1974 carrying the first atomic clock into orbit and the fourth launched in 1977. Another important predecessor to GPS came from a different branch of
4770-531: The Navy was developing the submarine-launched Polaris missile, which required them to know the submarine's location.) This led them and APL to develop the TRANSIT system. In 1959, ARPA (renamed DARPA in 1972) also played a role in TRANSIT. TRANSIT was first successfully tested in 1960. It used a constellation of five satellites and could provide a navigational fix approximately once per hour. In 1967,
4876-416: The Pentagon was the only federal agency that had not released annual audits as required by a 1992 law. According to Reuters, the Pentagon "annually reports to Congress that its books are in such disarray that an audit is impossible". In 2015, a Pentagon consulting firm performed an audit on the Department of Defense's budget. It found that there was $ 125 billion in wasteful spending that could be saved over
4982-442: The President to the Secretary of Defense, the service chief of the Unified Combatant Commander(s), and then to the unified combatant commander(s). Also provided in this legislation was a centralized research authority, the Advanced Research Projects Agency , eventually known as DARPA . The act was written and promoted by the Eisenhower administration and was signed into law on August 6, 1958. The Secretary of Defense , appointed by
5088-496: The SLBM situation. In 1960, the Air Force proposed a radio-navigation system called MOSAIC (MObile System for Accurate ICBM Control) that was essentially a 3-D LORAN System. A follow-on study, Project 57, was performed in 1963 and it was "in this study that the GPS concept was born". That same year, the concept was pursued as Project 621B, which had "many of the attributes that you now see in GPS" and promised increased accuracy for U.S. Air Force bombers as well as ICBMs. Updates from
5194-458: The Space Development Agency ( SDA ) and the Pentagon Force Protection Agency ( PFPA ), all of which are subordinate to the secretary of defense. Additionally, the Defense Contract Management Agency ( DCMA ) is responsible for administering contracts for the Department of Defense. Military operations are managed by eleven regional or functional unified combatant commands . The Department of Defense also operates several joint services schools, including
5300-473: The TOTs, the receiver forms four time of flight (TOF) values, which are (given the speed of light) approximately equivalent to receiver-satellite ranges plus time difference between the receiver and GPS satellites multiplied by speed of light, which are called pseudo-ranges. The receiver then computes its three-dimensional position and clock deviation from the four TOFs. In practice the receiver position (in three dimensional Cartesian coordinates with origin at
5406-402: The U.S. Department of Defense is the second largest employer in the world after India (and potentially China, if including the Central Military Commission), with over 1.4 million active-duty service personnel, including soldiers, marines, sailors, airmen, and guardians. The Department of Defense also maintains over 778,000 National Guard and reservists, and over 747,000 civilians, bringing
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#17327728169255512-552: The U.S. Navy developed the Timation satellite, which proved the feasibility of placing accurate clocks in space, a technology required for GPS. In the 1970s, the ground-based OMEGA navigation system, based on phase comparison of signal transmission from pairs of stations, became the first worldwide radio navigation system. Limitations of these systems drove the need for a more universal navigation solution with greater accuracy. Although there were wide needs for accurate navigation in military and civilian sectors, almost none of those
5618-442: The U.S. Secretary of Defense, William Perry , in view of the widespread growth of differential GPS services by private industry to improve civilian accuracy. Moreover, the U.S. military was developing technologies to deny GPS service to potential adversaries on a regional basis. Selective Availability was removed from the GPS architecture beginning with GPS-III. Since its deployment, the U.S. has implemented several improvements to
5724-416: The US government announced that the next generation of GPS satellites would not include the feature at all. Advances in technology and new demands on the existing system have now led to efforts to modernize the GPS and implement the next generation of GPS Block III satellites and Next Generation Operational Control System (OCX) which was authorized by the U.S. Congress in 2000. When Selective Availability
5830-425: The Unified Combatant Commands are responsible for military forces' actual operational command. Almost all operational U.S. forces are under the authority of a Unified Command. The Unified Commands are governed by a Unified Command Plan —a frequently updated document (produced by the DoD), which lays out the Command's mission, geographical/functional responsibilities, and force structure. During military operations,
5936-422: The United States , the latter of which is also the commander-in-chief of the United States Armed Forces . Beneath the Department of Defense are three subordinate military departments: the Department of the Army , the Department of the Navy , and the Department of the Air Force . In addition, four national intelligence services are subordinate to the Department of Defense: the Defense Intelligence Agency ( DIA ),
6042-444: The United States military. In 1964, the United States Army orbited its first Sequential Collation of Range ( SECOR ) satellite used for geodetic surveying. The SECOR system included three ground-based transmitters at known locations that would send signals to the satellite transponder in orbit. A fourth ground-based station, at an undetermined position, could then use those signals to fix its location precisely. The last SECOR satellite
6148-521: The allocation for the Department of Defense was $ 585 billion, the highest level of budgetary resources among all federal agencies, and this amounts to more than one-half of the annual federal expenditures in the United States federal budget discretionary budget . On September 28, 2018, President Donald Trump signed the Department of Defense and Labor, Health and Human Services, and Education Appropriations Act, 2019, and Continuing Appropriations Act, 2019 (H.R.6157) into law. On September 30, 2018,
6254-451: The axis of the hyperboloid. The receiver is located at the point where three hyperboloids intersect. It is sometimes incorrectly said that the user location is at the intersection of three spheres. While simpler to visualize, this is the case only if the receiver has a clock synchronized with the satellite clocks (i.e., the receiver measures true ranges to the satellites rather than range differences). There are marked performance benefits to
6360-450: The basic position calculations, do not use it at all. United States Department of Defense The United States Department of Defense ( DoD , USDOD , or DOD ) is an executive branch department of the federal government of the United States charged with coordinating and supervising all agencies and functions of the U.S. government directly related to national security and the United States Armed Forces . As of November 2022,
6466-438: The budgeted global military spending – more than the next 7 largest militaries combined. By 2019, the 27th secretary of defense had begun a line-by-line review of the defense budget; in 2020 the secretary identified items amounting to $ 5.7 billion, out of a $ 106 billion subtotal (the so-called "fourth estate" agencies such as missile defense, and defense intelligence, amounting to 16% of the defense budget), He will re-deploy to
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#17327728169256572-404: The chain of command runs from the president to the secretary of defense to the combatant commanders of the Combatant Commands. As of 2019 , the United States has eleven Combatant Commands, organized either on a geographical basis (known as " area of responsibility ", AOR) or on a global, functional basis: Department of Defense spending in 2017 was 3.15% of GDP and accounted for about 38% of
6678-430: The chairman has to present that advice whenever he is presenting his own. The chain of command goes from the president to the secretary of defense to the commanders of the Combatant Commands . Goldwater–Nichols also created the office of vice-chairman, and the chairman is now designated as the principal military adviser to the secretary of defense, the Homeland Security Council, the National Security Council and to
6784-587: The clocks on GPS satellites, as observed by those on Earth, run 38 microseconds faster per day than those on the Earth. The design of GPS corrects for this difference; because without doing so, GPS calculated positions would accumulate errors of up to 10 kilometers per day (6 mi/d). When the Soviet Union launched its first artificial satellite ( Sputnik 1 ) in 1957, two American physicists, William Guier and George Weiffenbach, at Johns Hopkins University 's Applied Physics Laboratory (APL) monitored its radio transmissions. Within hours they realized that, because of
6890-440: The debt ceiling was suspended until 2025. The $ 886 billion National Defense Authorization Act is facing reconciliation of the House and Senate bills after passing both houses 27 July 2023; the conferees have to be chosen, next. As of September 2023, a Continuing resolution is needed to prevent a Government shutdown . A shutdown was avoided on 30 September for 45 days (until 17 November 2023), with passage of
6996-438: The department were streamlined while still maintaining the ordinary jurisdiction of the Military Departments to organize, train, and equip their associated forces. The Act clarified the overall decision-making authority of the secretary of defense concerning these subordinate Military Departments. It more clearly defined the operational chain of command over U.S. military forces (created by the military departments) as running from
7102-496: The distance from the satellite to the ground station. With the distance information collected from multiple ground stations, the location coordinates of any satellite at any time can be calculated with great precision. Each GPS satellite carries an accurate record of its own position and time, and broadcasts that data continuously. Based on data received from multiple GPS satellites , an end user's GPS receiver can calculate its own four-dimensional position in spacetime ; However, at
7208-451: The distance traveled between two position measurements drops below or near the random error of position measurement. GPS units can use measurements of the Doppler shift of the signals received to compute velocity accurately. More advanced navigation systems use additional sensors like a compass or an inertial navigation system to complement GPS. GPS requires four or more satellites to be visible for accurate navigation. The solution of
7314-407: The effect of both SA degradation and atmospheric effects (that military receivers also corrected for). The U.S. military had also developed methods to perform local GPS jamming, meaning that the ability to globally degrade the system was no longer necessary. As a result, United States President Bill Clinton signed a bill ordering that Selective Availability be disabled on May 1, 2000; and, in 2007 ,
7420-456: The first secretary of defense. The National Military Establishment was renamed the "Department of Defense" on August 10, 1949, and absorbed the three cabinet-level military departments, in an amendment to the original 1947 law. The renaming is alleged to be due to the Establishment's abbreviation, NME, being pronounced "enemy". Under the Department of Defense Reorganization Act of 1958 ( Pub. L. 85–599 ), channels of authority within
7526-407: The highest-quality signal was reserved for military use, and the signal available for civilian use was intentionally degraded, in a policy known as Selective Availability . This changed on May 1, 2000, with U.S. President Bill Clinton signing a policy directive to turn off Selective Availability to provide the same accuracy to civilians that was afforded to the military. The directive was proposed by
7632-404: The jurisdiction of other congressional committees. The Department of Defense is unique because it is one of the few federal entities where the majority of its funding falls into the discretionary category. The majority of the entire federal budget is mandatory, and much of the discretionary funding in the budget consists of DoD dollars. * Numbers may not add due to rounding As of 10 March 2023
7738-496: The latest Center for Effective Government analysis of 15 federal agencies which receive the most Freedom of Information Act requests, published in 2015 (using 2012 and 2013 data, the most recent years available), the DoD earned 61 out of a possible 100 points, a D− grade. While it had improved from a failing grade in 2013, it still had low scores in processing requests (55%) and disclosure rules (42%). The organization and functions of
7844-578: The majority of the National Defense Budget of approximately $ 716.0 billion in discretionary spending and $ 10.8 billion in mandatory spending for a $ 726.8 billion total. Of the total, $ 708.1 billion falls under the jurisdiction of the House Committee on Armed Services and Senate Armed Services Committee and is subject to authorization by the annual National Defense Authorization Act (NDAA). The remaining $ 7.9 billion falls under
7950-589: The modernization of hypersonics, artificial intelligence, and missile defense. Beyond 2021 the 27th secretary of defense is projecting the need for yearly budget increases of 3 to 5 percent to modernize. The Department of Defense accounts for the majority of federal discretionary spending. In FY 2017, the Department of Defense budgeted spending accounted for 15% of the U.S. federal budget, and 49% of federal discretionary spending , which represents funds not accounted for by pre-existing obligations. However, this does not include many military-related items that are outside
8056-543: The most significant development for safe and efficient navigation and surveillance of air and spacecraft since the introduction of radio navigation 50 years ago". Two GPS developers received the National Academy of Engineering Charles Stark Draper Prize for 2003: GPS developer Roger L. Easton received the National Medal of Technology on February 13, 2006. Francis X. Kane (Col. USAF, ret.)
8162-658: The necessity of having a national army that could move about and fight beyond the boundaries of any particular colony, organized the Continental Army on June 14, 1775. This momentous event is commemorated in the U.S. annually as Flag Day . Later that year, Congress would charter the Continental Navy on October 13, and the Continental Marines on November 10. Upon the seating of the 1st U.S. Congress on March 4, 1789, legislation to create
8268-542: The need of the Corsair II, the Navy need the Corsair II to allow the first SLAM to blast a hole, allowing the 2nd SLAM to fly through the hole and cause damage. The last SLAM used in the war was fired that same night against a dam known to generate electricity near Al Qa'im. The dam was reportedly disabled with that single hit. The strike itself was also successful in that it enabled the Intruder to attack without entering
8374-440: The new measurements are collected, the receiver uses a weighting scheme to combine the new measurements with the tracker prediction. In general, a tracker can (a) improve receiver position and time accuracy, (b) reject bad measurements, and (c) estimate receiver speed and direction. The disadvantage of a tracker is that changes in speed or direction can be computed only with a delay, and that derived direction becomes inaccurate when
8480-579: The next five years without layoffs or reduction in military personnel. In 2016, The Washington Post uncovered that rather than taking the advice of the auditing firm, senior defense officials suppressed and hid the report from the public to avoid political scrutiny. In June 2016, the Office of the Inspector General released a report stating that the Army made $ 6.5 trillion in wrongful adjustments to its accounting entries in 2015. The Department of Defense failed its fifth audit in 2022, and could not account for more than 60% of its $ 3.5 trillion in assets. In
8586-487: The nuclear triad, also had requirements for a more accurate and reliable navigation system. The U.S. Navy and U.S. Air Force were developing their own technologies in parallel to solve what was essentially the same problem. To increase the survivability of ICBMs, there was a proposal to use mobile launch platforms (comparable to the Soviet SS-24 and SS-25 ) and so the need to fix the launch position had similarity to
8692-524: The precision needed for GPS. The design of GPS is based partly on similar ground-based radio-navigation systems, such as LORAN and the Decca Navigator System , developed in the early 1940s. In 1955, Friedwardt Winterberg proposed a test of general relativity —detecting time slowing in a strong gravitational field using accurate atomic clocks placed in orbit inside artificial satellites. Special and general relativity predicted that
8798-544: The president cited wasteful military spending and interdepartmental conflicts. Deliberations in Congress went on for months focusing heavily on the role of the military in society and the threat of granting too much military power to the executive. On July 26, 1947, Truman signed the National Security Act of 1947 , which set up a unified military command known as the National Military Establishment and created
8904-608: The president following U.S. Senate confirmation. Each of the individual Military Service Chiefs, outside their Joint Chiefs of Staff obligations, works directly for the secretary of the military department concerned: the Secretary of the Army , Secretary of the Navy , and Secretary of the Air Force . Following the Goldwater–Nichols Act in 1986, the Joint Chiefs of Staff no longer maintained operational command authority individually or collectively. The act designated
9010-559: The president on military matters. The composition of the Joint Chiefs of Staff is defined by statute and consists of the chairman of the Joint Chiefs of Staff (CJCS), vice chairman of the Joint Chiefs of Staff (VCJCS), senior enlisted advisor to the chairman (SEAC), the Military Service chiefs from the Army , Marine Corps , Navy , Air Force , and Space Force , in addition to the chief of National Guard Bureau , all appointed by
9116-478: The president or by the secretary of defense. Department of Defense Directive 5100.01 describes the organizational relationships within the department and is the foundational issuance for delineating the major functions of the department. The latest version, signed by former Secretary of Defense Robert Gates in December 2010, is the first major re-write since 1987. The Office of the Secretary of Defense ( OSD )
9222-470: The president with the advice and consent of the Senate , is by federal law ( 10 U.S.C. § 113 ) the head of the Department of Defense, "the principal assistant to the President in all matters relating to Department of Defense", and has "authority, direction, and control over the Department of Defense". Because the Constitution vests all military authority in Congress and the president,
9328-570: The president. The Joint Staff (JS) is a headquarters staff at the Pentagon made up of personnel from all five services that assist the chairman and vice chairman in discharging their duties. It is managed by the Director of the Joint Staff (DJS) who is a lieutenant general or vice admiral . There are three military departments within the Department of Defense: The Military Departments are each headed by their secretary (i.e., Secretary of
9434-703: The reason for the ultra-secrecy at that time. The nuclear triad consisted of the United States Navy's submarine-launched ballistic missiles (SLBMs) along with United States Air Force (USAF) strategic bombers and intercontinental ballistic missiles (ICBMs). Considered vital to the nuclear deterrence posture, accurate determination of the SLBM launch position was a force multiplier . Precise navigation would enable United States ballistic missile submarines to get an accurate fix of their positions before they launched their SLBMs. The USAF, with two thirds of
9540-408: The reference atomic clocks at the ground control stations; any drift of the clocks aboard the satellites from the reference time maintained on the ground stations is corrected regularly. Since the speed of radio waves ( speed of light ) is constant and independent of the satellite speed, the time delay between when the satellite transmits a signal and the ground station receives it is proportional to
9646-474: The statutory authority of the secretary of defense is derived from their constitutional authority. Since it is impractical for either Congress or the president to participate in every piece of Department of Defense affairs, the secretary of defense and the secretary's subordinate officials generally exercise military authority. The Department of Defense is composed of the Office of the Secretary of Defense ( OSD ),
9752-456: The total budgetary resources for fiscal year 2010 were $ 1.2 trillion. Of these resources, $ 1.1 trillion were obligated and $ 994 billion were disbursed, with the remaining resources relating to multi-year modernization projects requiring additional time to procure. After over a decade of non-compliance , Congress has established a deadline of Fiscal year 2017 for the Department of Defense to achieve audit readiness . In 2015
9858-479: The total to over 2.91 million employees. Headquartered at the Pentagon in Arlington County, Virginia , just outside Washington, D.C. , the Department of Defense's stated mission is "to provide the military forces needed to deter war and ensure our nation's security". The Department of Defense is headed by the secretary of defense , a cabinet-level head who reports directly to the president of
9964-404: The usefulness of the GPS positioning information. It provides critical positioning capabilities to military, civil, and commercial users around the world. Although the United States government created, controls, and maintains the GPS system, it is freely accessible to anyone with a GPS receiver. The GPS project was started by the U.S. Department of Defense in 1973. The first prototype spacecraft
10070-403: The user carrying a clock synchronized with the satellites. Foremost is that only three satellites are needed to compute a position solution. If it were an essential part of the GPS concept that all users needed to carry a synchronized clock, a smaller number of satellites could be deployed, but the cost and complexity of the user equipment would increase. The description above is representative of
10176-579: Was allowed from the 1980s. Roger L. Easton of the Naval Research Laboratory , Ivan A. Getting of The Aerospace Corporation , and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it. The work of Gladys West on the creation of the mathematical geodetic Earth model is credited as instrumental in the development of computational techniques for detecting satellite positions with
10282-420: Was concerned with the curving of the paths of radio waves ( atmospheric refraction ) traversing the ionosphere from NavSTAR satellites. After Korean Air Lines Flight 007 , a Boeing 747 carrying 269 people, was shot down by a Soviet interceptor aircraft after straying in prohibited airspace because of navigational errors, in the vicinity of Sakhalin and Moneron Islands , President Ronald Reagan issued
10388-490: Was destroyed in a launch failure). The effect of the ionosphere on radio transmission was investigated in a geophysics laboratory of Air Force Cambridge Research Laboratory , renamed to Air Force Geophysical Research Lab (AFGRL) in 1974. AFGRL developed the Klobuchar model for computing ionospheric corrections to GPS location. Of note is work done by Australian space scientist Elizabeth Essex-Cohen at AFGRL in 1974. She
10494-703: Was discontinued, GPS was accurate to about 5 meters (16 ft). GPS receivers that use the L5 band have much higher accuracy of 30 centimeters (12 in), while those for high-end applications such as engineering and land surveying are accurate to within 2 cm ( 3 ⁄ 4 in) and can even provide sub-millimeter accuracy with long-term measurements. Consumer devices such as smartphones can be accurate to 4.9 m (16 ft) or better when used with assistive services like Wi-Fi positioning . As of July 2023 , 18 GPS satellites broadcast L5 signals, which are considered pre-operational prior to being broadcast by
10600-625: Was inducted into the U.S. Air Force Space and Missile Pioneers Hall of Fame at Lackland A.F.B., San Antonio, Texas, March 2, 2010, for his role in space technology development and the engineering design concept of GPS conducted as part of Project 621B. In 1998, GPS technology was inducted into the Space Foundation Space Technology Hall of Fame . On October 4, 2011, the International Astronautical Federation (IAF) awarded
10706-626: Was launched in 1969. With these parallel developments in the 1960s, it was realized that a superior system could be developed by synthesizing the best technologies from 621B, Transit, Timation, and SECOR in a multi-service program. Satellite orbital position errors, induced by variations in the gravity field and radar refraction among others, had to be resolved. A team led by Harold L. Jury of Pan Am Aerospace Division in Florida from 1970 to 1973, used real-time data assimilation and recursive estimation to do so, reducing systematic and residual errors to
10812-453: Was launched in 1978 and the full constellation of 24 satellites became operational in 1993. After Korean Air Lines Flight 007 was shot down when it mistakenly entered Soviet airspace, President Ronald Reagan announced that the GPS system would be made available for civilian use as of September 16, 1983; however, initially this civilian use was limited to an average accuracy of 100 meters (330 ft) by use of Selective Availability (SA),
10918-549: Was never considered as such by the GPS Joint Program Office (TRW may have once advocated for a different navigational system that used that acronym). With the individual satellites being associated with the name Navstar (as with the predecessors Transit and Timation), a more fully encompassing name was used to identify the constellation of Navstar satellites, Navstar-GPS . Ten " Block I " prototype satellites were launched between 1978 and 1985 (an additional unit
11024-530: Was seen as justification for the billions of dollars it would cost in research, development, deployment, and operation of a constellation of navigation satellites. During the Cold War arms race , the nuclear threat to the existence of the United States was the one need that did justify this cost in the view of the United States Congress. This deterrent effect is why GPS was funded. It is also
11130-536: Was stripped from them in the Defense Reorganization Act of 1958 ), and instead, Military Departments are tasked solely with "the training, provision of equipment, and administration of troops." A unified combatant command is a military command composed of personnel/equipment from at least two Military Departments, which has a broad/continuing mission. These military departments are responsible for equipping and training troops to fight, while
11236-529: Was ultimately used to determine the orbit of the GPS constellation. On February 12, 2019, four founding members of the project were awarded the Queen Elizabeth Prize for Engineering with the chair of the awarding board stating: "Engineering is the foundation of civilisation; ...They've re-written, in a major way, the infrastructure of our world." The GPS satellites carry very stable atomic clocks that are synchronized with one another and with
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