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117-859: Since the first one was built in August 1956, the C-135 and its variants have been a fixture of the United States Air Force . It was developed from the Boeing KC-135 Stratotanker . In the early 1960s, the Military Air Transport Service operated a fleet consisting almost entirely of propeller-driven aircraft such as the piston-powered Douglas C-124 Globemaster II and C-133 Cargomaster turboprop. While capable of carrying large, outsized payloads, they were becoming increasingly obsolescent and lacked

234-471: A completely different aircraft . Eighteen C-135A s (Boeing model number 717-157 ), powered by Pratt & Whitney J57 turbojets , were built. In later years, almost all were upgraded with Pratt & Whitney TF33 turbofan engines and wide-span horizontal stabilizers, and were re-designated C-135E . Most were converted to various special roles, including airborne command posts, missile-tracking platforms, and VIP transports, and were withdrawn throughout

351-408: 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

468-459: A radome to test the camera's generation of video images of the forward scene in low-visibility conditions. The aircraft, which in the VIP /Distinguished Visitor (DV) transport role seats 14 passengers, also gives a Joint Forces Air Component Commander (JFACC) a limited ability to plan and control the simulated battle while in the air en route to the crisis area. Speckled Trout is the official name of

585-564: A "systemic problem" in the USAF's management of the nuclear mission. GPS The Global Positioning System ( GPS ), originally Navstar GPS , 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

702-426: A broader dimension of time or space than do tactics; they provide the means by which tactical successes are exploited to achieve strategic and operational objectives. Tactical Level Command and Control is where individual battles and engagements are fought. The tactical level of war deals with how forces are employed, and the specifics of how engagements are conducted and targets attacked. The goal of tactical level C2

819-438: A cleanup plan for drinking water around Tucson, Arizona after the region's groundwater was contaminated by PFAS runoff from nearby Air Force bases. The United States Air Force has been involved in many wars, conflicts and operations using military air operations. The USAF possesses the lineage and heritage of its predecessor organizations, which played a pivotal role in U.S. military operations since 1907: In addition since

936-615: A combined SAF/CSAF support mission and concurrent test mission. It was also the official nickname given to a modified C-135C, serial number 61–2669, that was used by the Secretary and the Chief of Staff of the Air Force for executive transport requirements. Fully equipped with an array of communications equipment, data links and cryptographic sets, the aircraft served a secondary role as a testbed for proposed command and control systems and

1053-458: A commander in planning, directing, coordinating, and controlling forces and operations in the accomplishment of the mission" (JP 1-02). This core function includes all of the C2-related capabilities and activities associated with air, cyberspace, nuclear, and agile combat support operations to achieve strategic, operational, and tactical objectives. At the strategic level command and control,

1170-450: 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,

1287-894: A force multiplier. It allows air assets to more rapidly reach any trouble spot around the world with less dependence on forward staging bases or overflight/landing clearances. Air refueling significantly expands the options available to a commander by increasing the range, payload, persistence, and flexibility of receiver aircraft. Aeromedical evacuation is "the movement of patients under medical supervision to and between medical treatment facilities by air transportation" (JP 1-02). JP 4-02, Health Service Support, further defines it as "the fixed wing movement of regulated casualties to and between medical treatment facilities, using organic and/or contracted mobility airframes, with aircrew trained explicitly for this mission." Aeromedical evacuation forces can operate as far forward as fixed-wing aircraft are able to conduct airland operations. Global precision attack

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1404-517: 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

1521-429: 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

1638-563: 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

1755-461: 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

1872-523: A nation state, or non-state/transnational actor. The Air Force maintains and presents credible deterrent capabilities through successful visible demonstrations and exercises that assure allies, dissuade proliferation, deter potential adversaries from actions that threaten US national security or the populations, and deploy military forces of the US, its allies, and friends. Nuclear strike is the ability of nuclear forces to rapidly and accurately strike targets which

1989-405: A precondition" (Annex 3–70, Strategic Attack). Air Interdiction is defined as "air operations conducted to divert, disrupt, delay, or destroy the enemy's military potential before it can be brought to bear effectively against friendly forces, or to otherwise achieve JFC objectives. Air Interdiction is conducted at such distance from friendly forces that detailed integration of each air mission with

2106-494: A rapid cessation of hostilities. Post-conflict, regeneration of a credible nuclear deterrent capability will deter further aggression. The Air Force may present a credible force posture in either the Continental United States , within a theater of operations, or both to effectively deter the range of potential adversaries envisioned in the 21st century. This requires the ability to engage targets globally using

2223-431: 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

2340-603: A sharp reduction in flight hours for crew training since 2005 and the Deputy Chief of Staff for Manpower and Personnel directing Airmen's Time Assessments. On 5 June 2008, Secretary of Defense Robert Gates accepted the resignations of both the Secretary of the Air Force , Michael Wynne , and the Chief of Staff of the Air Force , General T. Michael Moseley . In his decision to fire both men Gates cited "systemic issues associated with... declining Air Force nuclear mission focus and performance". Left unmentioned by Gates

2457-452: A strong focus on the improvement of Basic Military Training (BMT) for enlisted personnel. While the intense training has become longer, it also has shifted to include a deployment phase. This deployment phase, now called the BEAST, places the trainees in a simulated combat environment that they may experience once they deploy. While the trainees do tackle the massive obstacle courses along with

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2574-510: A variety of methods; therefore, the Air Force should possess the ability to induct, train, assign, educate and exercise individuals and units to rapidly and effectively execute missions that support US NDO objectives. Finally, the Air Force regularly exercises and evaluates all aspects of nuclear operations to ensure high levels of performance. Nuclear surety ensures the safety, security and effectiveness of nuclear operations. Because of their political and military importance, destructive power, and

2691-459: Is "the acquisition of information and the provision of this information to processing elements" (JP 2-01). It provides the ability to obtain required information to satisfy intelligence needs (via use of sources and methods in all domains). Collection activities span the Range of Military Operations (ROMO). Processing and exploitation is "the conversion of collected information into forms suitable to

2808-417: Is "the employment of limited offensive action and counterattacks to deny a contested area or position to the enemy" (JP 1-02). It includes both ballistic missile defense and airborne threat defense and encompasses point defense, area defense, and high-value airborne asset defense. Passive defense is "measures taken to reduce the probability of and to minimize the effects of damage caused by hostile action without

2925-425: Is defined as "all the defensive measures designed to detect, identify, intercept, and destroy or negate enemy forces attempting to penetrate or attack through friendly airspace" (JP 1-02). In concert with OCA operations, a major goal of DCA operations is to provide an area from which forces can operate, secure from air and missile threats. The DCA mission comprises both active and passive defense measures. Active defense

3042-534: Is defined as "offensive operations to destroy, disrupt, or neutralize enemy aircraft, missiles, launch platforms, and their supporting structures and systems both before and after launch, but as close to their source as possible" (JP 1-02). OCA is the preferred method of countering air and missile threats since it attempts to defeat the enemy closer to its source and typically enjoys the initiative. OCA comprises attack operations, sweep, escort, and suppression/destruction of enemy air defense. Defensive Counter-Air (DCA)

3159-527: 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

3276-725: Is the air service branch of the United States Armed Forces , and is one of the eight uniformed services of the United States . Originally created on 1 August 1907, as a part of the United States Army Signal Corps , the USAF was established as a separate branch of the United States Armed Forces in 1947 with the enactment of the National Security Act of 1947 . It is the second youngest branch of

3393-486: Is the ability to hold at risk or strike rapidly and persistently, with a wide range of munitions, any target and to create swift, decisive, and precise effects across multiple domains. Strategic attack is defined as "offensive action specifically selected to achieve national strategic objectives. These attacks seek to weaken the adversary's ability or will to engage in conflict, and may achieve strategic objectives without necessarily having to achieve operational objectives as

3510-583: Is the cornerstone of the credibility of the NDO mission. Positive nuclear command, control, communications; effective nuclear weapons security; and robust combat support are essential to the overall NDO function. Command and control is "the exercise of authority and direction by a properly designated commander over assigned and attached forces in the accomplishment of the mission. Command and control functions are performed through an arrangement of personnel, equipment, communications, facilities, and procedures employed by

3627-684: Is to achieve commander's intent and desired effects by gaining and keeping offensive initiative. The origins of the United States Air Force can be traced back to the Union Army Balloon Corps of the American Civil War . The Union Balloon Corps, established by aeronaut Thaddeus S. C. Lowe , provided aerial reconnaissance for the Union Army . This early use of balloons for military purposes marked

Boeing C-135 Stratolifter - Misplaced Pages Continue

3744-429: Is to provide what the Air Force states as global vigilance, global reach, and global power. Air superiority is "that degree of dominance in the air battle of one force over another which permits the conduct of operations by the former and its related land, sea, air, and special operations forces at a given time and place without prohibitive interference by the opposing force" (JP 1-02). Offensive Counter-Air (OCA)

3861-760: 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

3978-689: The Bomber Mafia ), followed by fighters ( Fighter Mafia ). In response to a 2007 United States Air Force nuclear weapons incident , Secretary of Defense Robert Gates accepted in June 2009 the resignations of Secretary of the Air Force Michael Wynne and the Chief of Staff of the Air Force General T. Michael Moseley . Moseley's successor, General Norton A. Schwartz , a former airlift and special operations pilot,

4095-503: 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,

4212-614: The Joint Chiefs of Staff . As directed by the Secretary of Defense and Secretary of the Air Force, certain Air Force components are assigned to unified combatant commands . Combatant commanders are delegated operational authority of the forces assigned to them, while the Secretary of the Air Force and the Chief of Staff of the Air Force retain administrative authority over their members. Along with conducting independent air operations,

4329-574: The National Security Act of 1947 (61 Stat . 502), which created the USAF: Section 9062 of Title 10 US Code defines the purpose of the USAF as: The five core missions of the Air Force have not changed dramatically since the Air Force became independent in 1947, but they have evolved and are now articulated as air superiority, global integrated ISR (intelligence, surveillance and reconnaissance), rapid global mobility, global strike, and command and control. The purpose of all of these core missions

4446-504: 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

4563-581: The 1970s to 2006, and remain in service with further equipment upgrades installed. The C-135C designation applies to three WC-135B (originally converted from C-135B) weather reconnaissance aircraft, which were de-modified to transport status. Most of the other C-135Bs were converted to various special mission variants following their service with the Military Airlift Command . C-135Cs also retained their air refueling receptacle, added during modifications to WC-135 standard. Although most of

4680-547: The 1990s. The C-135E designation was also applied to EC-135Ns that were used in the combat support role. Thirty C-135B s (Boeing model number 717-158 ) were built new with the TF33 turbofan and improved wide-span horizontal stabilizers. Ten were modified for a weather reconnaissance (flying through radioactive clouds from nuclear tests or other agents) role and designated WC-135B Stratolifter ( Constant Phoenix in later versions). Additional airframes were converted to RC-135s from

4797-471: The 820 airframes of this type built were KC-135A Stratotankers , equipped to provide mid-air refueling to other aircraft. Forty-five base-model aircraft were built as C-135A or C-135B transports with the tanking equipment excluded; three more aircraft originally ordered as KC-135A were factory converted to C-135A. The C-135/KC-135 type was also known internally at Boeing as the Model 717 , a name later assigned to

Boeing C-135 Stratolifter - Misplaced Pages Continue

4914-422: The Air Force's readiness to carry out the nuclear strike operations mission as well as from specific actions taken to assure allies as a part of extended deterrence. Dissuading others from acquiring or proliferating WMD and delivering them contributes to promoting security and is also an integral part of this mission. Moreover, different deterrence strategies are required to deter various adversaries, whether they are

5031-547: The BEAST, the other portions include defending and protecting their base of operations, forming a structure of leadership, directing search and recovery, and basic self aid buddy care. During this event, the Military Training Instructors (MTI) act as mentors and opposing forces in a deployment exercise. In November 2022, the USAF announced that it will discontinue BEAST and replace it with another deployment training program called PACER FORGE. In 2007,

5148-786: The C-135C could not. C-135F (Boeing model number 717-164 ) was new-built variant for France as a dual-role tanker/cargo and troop carrier aircraft. 12 were built for the French Air Force with the addition of a drogue adapter on the refueling boom. 11 surviving C-135Fs upgraded to C-135FRs with CFM International F108 turbofans between 1985 and 1988. Later modified with MPRS wing pods. One former EC-135K modified for VIP use for CINCPAC . General characteristics Performance Related development Aircraft of comparable role, configuration, and era United States Air Force The United States Air Force ( USAF )

5265-509: 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 the usefulness of the GPS positioning information. It provides critical positioning capabilities to military, civil, and commercial users around the world. Although

5382-524: 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

5499-910: 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 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

5616-604: 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

5733-668: 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

5850-410: 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), 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

5967-740: 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

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6084-797: The Navy , and the newly created Department of the Air Force. Prior to 1947, the responsibility for military aviation was shared between the Army Air Forces and its predecessor organizations (for land-based operations), the Navy (for sea-based operations from aircraft carriers and amphibious aircraft), and the Marine Corps (for close air support of Marine Corps operations). The 1940s proved to be important for military aviation in other ways as well. In 1947, Air Force Captain Chuck Yeager broke

6201-480: 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

6318-531: 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,

6435-461: The ROMO. The purpose of nuclear deterrence operations (NDO) is to operate, maintain, and secure nuclear forces to achieve an assured capability to deter an adversary from taking action against vital US interests. In the event deterrence fails, the US should be able to appropriately respond with nuclear options. The sub-elements of this function are: Assure/Dissuade/Deter is a mission set derived from

6552-547: 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

6669-524: 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

6786-607: 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

6903-442: 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

7020-543: The US determines national or multinational security objectives and guidance, and develops and uses national resources to accomplish these objectives. These national objectives in turn provide the direction for developing overall military objectives, which are used to develop the objectives and strategy for each theater. At the operational level command and control, campaigns and major operations are planned, conducted, sustained, and assessed to accomplish strategic goals within theaters or areas of operations. These activities imply

7137-514: The USAF dwarfs all other U.S. and allied air components, it often provides support for allied forces in conflicts to which the United States is otherwise not involved, such as the 2013 French campaign in Mali . The USAF has also taken part in numerous humanitarian operations. Some of the more major ones include the following: The culture of the United States Air Force is primarily driven by pilots, at first those piloting bombers (driven originally by

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7254-464: The USAF established the nuclear-focused Air Force Global Strike Command on 24 October 2008, which later assumed control of all USAF bomber aircraft. On 26 June 2009, the USAF released a force structure plan that cut fighter aircraft and shifted resources to better support nuclear, irregular and information warfare. On 23 July 2009, The USAF released their Unmanned Aerial System (UAS) Flight Plan, detailing Air Force UAS plans through 2047. One third of

7371-509: The USAF undertook a Reduction-in-Force (RIF). Because of budget constraints, the USAF planned to reduce the service's size from 360,000 active duty personnel to 316,000. The size of the active duty force in 2007 was roughly 64% of that of what the USAF was at the end of the first Gulf War in 1991. However, the reduction was ended at approximately 330,000 personnel in 2008 in order to meet the demand signal of combatant commanders and associated mission requirements. These same constraints have seen

7488-577: The United States Air Force provides air support for land and naval forces and aids in the recovery of troops in the field. As of 2020 , the service operates approximately 5,500 military aircraft and approximately 400 ICBMs . The world's largest air force, it has a $ 179.7 billion budget and is the second largest service branch of the U.S. Armed Forces, with 321,848 active duty airmen , 147,879 civilian personnel, 68,927 reserve airmen, 105,104 Air National Guard airmen, and approximately 65,000 Civil Air Patrol auxiliarists . According to

7605-462: The United States Armed Forces and the fourth in order of precedence . The United States Air Force articulates its core missions as air supremacy , global integrated intelligence, surveillance and reconnaissance , rapid global mobility , global strike , and command and control . The United States Air Force is a military service branch organized within the Department of the Air Force , one of

7722-469: 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 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

7839-512: 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

7956-526: The ability to fulfill their primary mission. Rapid Global Mobility is essential to virtually every military operation, allowing forces to reach foreign or domestic destinations quickly, thus seizing the initiative through speed and surprise. Airlift is "operations to transport and deliver forces and materiel through the air in support of strategic, operational, or tactical objectives" (Annex 3–17, Air Mobility Operations). The rapid and flexible options afforded by airlift allow military forces and national leaders

8073-425: 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 , 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

8190-407: The ability to integrate, evaluate, and interpret information from available sources to create a finished intelligence product for presentation or dissemination to enable increased situational awareness. Dissemination and integration is "the delivery of intelligence to users in a suitable form and the application of the intelligence to appropriate missions, tasks, and functions" (JP 2-01). It provides

8307-425: The ability to present information and intelligence products across the ROMO enabling understanding of the operational environment to military and national decision-makers. Rapid global mobility is the timely deployment, employment, sustainment, augmentation, and redeployment of military forces and capabilities across the ROMO. It provides joint military forces the capability to move from place to place while retaining

8424-455: The ability to respond and operate in a variety of situations and time frames. The global reach capability of airlift provides the ability to apply US power worldwide by delivering forces to crisis locations. It serves as a US presence that demonstrates resolve and compassion in humanitarian crisis. Air refueling is "the refueling of an aircraft in flight by another aircraft" (JP 1-02). Air refueling extends presence, increases range, and serves as

8541-451: 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

8658-430: The beginning of modern aerial warfare and set the stage for the development of the United States Air Force. The U.S. War Department created the first antecedent of the U.S. Air Force, as a part of the U.S. Army, on 1 August 1907, which through a succession of changes of organization, titles, and missions advanced toward eventual independence 40 years later. In World War II , almost 68,000 U.S. airmen died helping to win

8775-648: 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

8892-496: 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

9009-451: 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

9126-479: The enemy holds dear in a devastating manner. If a crisis occurs, rapid generation and, if necessary, deployment of nuclear strike capabilities will demonstrate US resolve and may prompt an adversary to alter the course of action deemed threatening to our national interest. Should deterrence fail, the President may authorize a precise, tailored response to terminate the conflict at the lowest possible level and lead to

9243-483: The fire and movement of friendly forces is not required" (Annex 3-03, Counterland Operations). Close Air Support is defined as "air action by fixed- and rotary-winged aircraft against hostile targets that are in close proximity to friendly forces and which require detailed integration of each air mission with the fire and movement of those forces" (JP 1-02). This can be as a pre-planned event or on demand from an alert posture (ground or airborne). It can be conducted across

9360-508: The global reach required of the rapidly-modernizing Air Force. In May 1960, Congress approved the purchase of 50 C-135 aircraft; it was selected in part because of its low development cost, being a straightforward derivative of the KC-135 tanker already in production. Ultimately, only 15 C-135As would be produced (in addition to three converted from KC-135s while still on the assembly line), with 30 additional aircraft being delivered as C-135Bs with

9477-603: The globe to conduct current and future operations. Planning and directing is "the determination of intelligence requirements, development of appropriate intelligence architecture, preparation of a collection plan, and issuance of orders and requests to information collection agencies" (JP 2-01, Joint and National Intelligence Support to Military Operations). These activities enable the synchronization and integration of collection, processing, exploitation, analysis, and dissemination activities/resources to meet information requirements of national and military decision-makers. Collection

9594-407: 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

9711-524: The improved Pratt & Whitney TF33 turbofan engine. The C-135 was largely intended as an interim measure pending the development of more specialized jet transports such as the Lockheed C-141 Starlifter , and as such it incorporated numerous compromises in its strategic airlift capability. The aircraft's load floor was some 10 feet (3.0 m) off the ground, which required ground-handling equipment, its single side-loading cargo door

9828-442: The intention of taking the initiative" (JP 1-02). It includes detection and warning; chemical, biological, radiological, and nuclear defense; camouflage, concealment, and deception; hardening; reconstitution; dispersion; redundancy; and mobility, counter-measures, and stealth. Airspace control is "a process used to increase operational effectiveness by promoting the safe, efficient, and flexible use of airspace" (JP 1-02). It promotes

9945-553: The largest military bases or commercial airports, which were not necessarily located in close proximity to potential combat areas. The Lockheed C-141 entered front-line service in April 1965, which finally gave MATS and its successor, Military Airlift Command , the strategic airlift capability it needed. By the early 1970s, the C-135 fleet had been modified and relegated to other duties, which included staff/VIP transport, systems testing, and strategic reconnaissance. The large majority of

10062-762: The mid-2030s. On 22 October 2023, the USAF conducted its first-ever trilateral exercise with the South Korean and Japanese air forces near the Korean Peninsula. On 29 November 2023, a USAF Bell Boeing V-22 Osprey crashed in the Japan island of Yakushima killing 1 airman. In 2024, citing the Supreme Court 's ruling in Loper Bright Enterprises v. Raimondo , the Air Force refused to comply with an EPA order that they develop

10179-543: 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.)

10296-440: 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

10413-487: 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

10530-415: The planes that the USAF planned to buy in the future were to be unmanned. According to Air Force Chief Scientist, Greg Zacharias , the USAF anticipates having hypersonic weapons by the 2020s, hypersonic unmanned aerial vehicles (also known as remotely-piloted vehicles, or RPAs) by the 2030s and recoverable hypersonic RPAs aircraft by the 2040s. The USAF intends to deploy a Sixth-generation jet fighter by

10647-486: The potential consequences of an accident or unauthorized act, nuclear weapons and nuclear weapon systems require special consideration and protection against risks and threats inherent in their peacetime and wartime environments. In conjunction with other entities within the Departments of Defense or Energy, the Air Force achieves a high standard of protection through a stringent nuclear surety program. This program applies to materiel, personnel, and procedures that contribute to

10764-524: 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

10881-483: The production of intelligence" (JP 2-01). It provides the ability to transform, extract, and make available collected information suitable for further analysis or action across the ROMO. Analysis and production is "the conversion of processed information into intelligence through the integration, evaluation, analysis, and interpretation of all source data and the preparation of intelligence products in support of known or anticipated user requirements" (JP 2-01). It provides

10998-585: The project. Trout reportedly had many freckles, hence the addition of "Speckled." Speckled Trout acquired the C-135C, serial number 61–2669, in 1974 and retired the aircraft on 13 January 2006. An interim aircraft was in use for the Speckled Trout mission until the 2008 delivery of the current aircraft, a modified KC-135R Stratotanker serial number 63–7980 with a more modern communications architecture testbed. The current KC-135R Speckled Trout also supports additional tests and air refueling requirements that

11115-652: 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

11232-408: 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

11349-424: The remaining C-135 aircraft are used for transporting senior military leaders and other high-ranking dignitaries, the C-135C communications aircraft serves as an aerial test-bed for emerging technologies. Developmental tests using this aircraft have demonstrated the capability to fly precision approaches using a local area differential GPS system. This modified C-135 has been fitted with a millimeter wave camera and

11466-491: The safe, efficient, and flexible use of airspace, mitigates the risk of fratricide, enhances both offensive and defensive operations, and permits greater agility of air operations as a whole. It both deconflicts and facilitates the integration of joint air operations. Global integrated intelligence, surveillance, and reconnaissance (ISR) is the synchronization and integration of the planning and operation of sensors, assets, and processing, exploitation, dissemination systems across

11583-602: The safety, security, and control of nuclear weapons, thus assuring no nuclear accidents, incidents, loss, or unauthorized or accidental use (a Broken Arrow incident ). The Air Force continues to pursue safe, secure and effective nuclear weapons consistent with operational requirements. Adversaries, allies, and the American people must be highly confident of the Air Force's ability to secure nuclear weapons from accidents, theft, loss, and accidental or unauthorized use. This day-to-day commitment to precise and reliable nuclear operations

11700-558: The sound barrier in his X-1 rocket-powered aircraft, beginning a new era of aeronautics in America. The predecessor organizations in the Army of today's Air Force are: During the early 2000s, two USAF aircraft procurement projects took longer than expected, the KC-X and F-35 programs. As a result, the USAF was setting new records for average aircraft age. Since 2005, the USAF has placed

11817-501: The three military departments of the Department of Defense . The Air Force through the Department of the Air Force is headed by the civilian Secretary of the Air Force , who reports to the Secretary of Defense and is appointed by the President with Senate confirmation . The highest-ranking military officer in the Air Force is the Chief of Staff of the Air Force , who exercises supervision over Air Force units and serves as one of

11934-403: 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

12051-467: The war, with only the infantry suffering more casualties. In practice, the U.S. Army Air Forces ( USAAF ) was virtually independent of the Army during World War II, and in virtually every way functioned as an independent service branch, but airmen still pressed for formal independence. The National Security Act of 1947 was signed on 26 July 1947, which established the Department of the Air Force , but it

12168-579: 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

12285-581: Was also used to evaluate future transport aircraft design. The 412th Flight Test Squadron (412 FLTS) of the Air Force Materiel Command (AFMC) at Edwards AFB , California operated the C-135 Speckled Trout airframe and managed its test mission. The name Speckled Trout applies to both the organization and the aircraft. The name was chosen in honor of an early program monitor, Faye Trout, who assisted in numerous phases of

12402-420: 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

12519-490: 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

12636-625: 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

12753-626: 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

12870-568: Was limited in what could fit through it, and its useful range was approximately 6,000 miles (9,700 km), insufficient to reach many of the Air Force's operating locations in Asia and the Pacific Rim. While range was greatly improved over earlier transports, it could not be augmented by aerial refueling, as C-135s were not configured with refueling receptacles. Additionally, its takeoff and landing performance required long runways available only at

12987-549: 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

13104-500: Was not until 18 September 1947, when the first secretary of the Air Force, W. Stuart Symington , was sworn into office that the Air Force was officially formed as an independent service branch. The act created the National Military Establishment (renamed Department of Defense in 1949), which was composed of three subordinate Military Departments, namely the Department of the Army , the Department of

13221-530: 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

13338-661: 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 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

13455-429: Was that he had repeatedly clashed with Wynne and Moseley over other important non-nuclear related issues to the service. This followed an investigation into two incidents involving mishandling of nuclear weapons : specifically a nuclear weapons incident aboard a B-52 flight between Minot AFB and Barksdale AFB , and an accidental shipment of nuclear weapons components to Taiwan. To put more emphasis on nuclear assets,

13572-530: Was the first officer appointed to that position who did not have a background as a fighter or bomber pilot. The Washington Post reported in 2010 that General Schwartz began to dismantle the rigid class system of the USAF, particularly in the officer corps. In 2014, following morale and testing/cheating scandals in the Air Force's missile launch officer community, Secretary of the Air Force Deborah Lee James admitted that there remained

13689-529: 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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