Global Positioning System

The CH-47 Chinook is a versatile, twin-engine, twin-rotor heavy-lift helicopter. The contra-rotating rotors eliminate the need for a rear vertical rotor, allowing all power to be used for lift and thrust, giving a top speed of 173 mph (150 knots, 278 km/h). Its primary roles include troop movement, artillery emplacement, and battlefield resupply. Chinooks have been sold to 16 nations, the largest users of which are the US Army and the Royal Air Force (see RAF Chinook). A commercial model, the Boeing 234 Chinook, is used worldwi ...

Including:

• CH-47 Chinook - Variants
• CH-47 Chinook - CH-47A
• CH-47 Chinook - A/ACH-47A/ACH-47A
• CH-47 Chinook - CH-47B
• CH-47 Chinook - CH-47C
• CH-47 Chinook - CH-47D
• CH-47 Chinook - CH-47F
• CH-47 Chinook - MH-47
• CH-47 Chinook - Units using the Chinook
• CH-47 Chinook - Problems with Chinook
• CH-47 Chinook - Reputation in the RAF
• CH-47 Chinook - Movies and Television

Read more here: » CH-47 Chinook: Encyclopedia - CH-47 Chinook

The Boeing IDS (formerly Rockwell) B-1B Lancer is a long-range strategic bomber in service with the USAF. Together with the B-52 Stratofortress, it is the backbone of the United States' long-range bomber force. B-1 Lancer - Development. The B-1 was conceived as the Advanced Manned Strategic Aircraft (AMSA) program circa 1965. After a prolonged development period, the contract was awarded in 1970 to Rockwell International. The first of four prototype B-1A models flew on December 23 1974. Intend ...

Including:

• B-1 Lancer - Development
• B-1 Lancer - Technology
• B-1 Lancer - Operational History
• B-1 Lancer - Crashes and malfunctions
• B-1 Lancer - Specifications B-1 Lancer
• B-1 Lancer - General characteristics
• B-1 Lancer - Performance
• B-1 Lancer - Armament
• B-1 Lancer - Units
• B-1 Lancer - Trivia
• B-1 Lancer - Related content

Read more here: » B-1 Lancer: Encyclopedia - B-1 Lancer

Information theory is the mathematical theory of data communication and storage, generally considered to have been founded in 1948 by Claude E. Shannon. The central paradigm of classic information theory is the engineering problem of the transmission of information over a noisy channel. The most fundamental results of this theory are Shannon's source coding theorem, which establishes that on average the number of bits needed to communicate the result of an uncertain event is given by the entropy of that uncertainty; and ...

Including:

• Information theory - Mathematical preliminaries
• Information theory - Basic Concepts for Discrete Channels
• Information theory - Self-information
• Information theory - Entropy
• Information theory - Joint Entropy
• Information theory - Conditional Entropy Equivocation
• Information theory - Mutual Information Transinformation
• Information theory - Continuous Channels
• Information theory - Channel Capacity
• Information theory - Source Theory
• Information theory - Rate
• Information theory - Fundamental Theorem
• Information theory - Statement Noisy-Channel Coding Theorem
• Information theory - Channel capacity of particular model channels
• Information theory - Related Concepts
• Information theory - Measure Theory
• Information theory - Kolmogorov Complexity
• Information theory - Applications
• Information theory - Coding Theory
• Information theory - Cryptography Cryptanalysis
• Information theory - Relation with thermodynamic entropy
• Information theory - Quantum Information Theory
• Information theory - Detection and Estimation Theory
• Information theory - Gambling
• Information theory - Intelligence
• Information theory - Music
• Information theory - History

Read more here: » Information theory: Encyclopedia - Information theory

The Polynesian navigators routinely crossed thousands of miles of open ocean, to tiny inhabited islands, using only their own senses and knowledge, passed by oral tradition, from navigator to apprentice. In Eastern Polynesia, navigators, in order to locate directions at various times of day and year, memorized extensive facts concerning: the motion of specific stars, and where they would rise and set on the horizon of the ocean weather times of travel wildlife species (which congregate at partic ...

See also:

Navigation, Navigation - Polynesian navigation, Navigation - Western navigation, Navigation - Modern methods, Navigation - History, Navigation - Point measure of direction

Read more here: » Navigation: Encyclopedia II - Navigation - Polynesian navigation

For military usage a primary drawback is lack of the ability to control emissions (EMCON) and stealth. Naval TACAN operations are designed so an aircraft can find the ship and land. There is no encryption involved, an enemy can simply use the range and bearing provided to attack the ship with a TACAN. It is likely that TACAN will be replaced with a differential GPS system similar to the Local Area Augmentation System called JPALS. The Joint Precision Approach and Landing System has a low probability of intercept to prevent enemy detection and an aircraft carrier version c ...

See also:

TACAN, TACAN - Operation, TACAN - Accuracy, TACAN - Benefits, TACAN - Drawbacks, TACAN - Future, TACAN - References, TACAN - External links

Read more here: » TACAN: Encyclopedia II - TACAN - Drawbacks

As of 2005, LAAS has a Category I precision approach capability. This is similar to the WAAS program, but since it covers most of North America, WAAS is far more cost effective. LAAS only covers a 20 to 30 mile area surrounding a single airport. However, research is underway to increase LAAS to Category III and support precision approaches in zero visibility. LAAS's VHF uplink signal is currently slated to share the frequency band from 108 MHz to 118 MHz with existing ILS localizer and VOR navigational aids. Some existing navaids will ...

See also:

Local Area Augmentation System, Local Area Augmentation System - History, Local Area Augmentation System - Operation, Local Area Augmentation System - Accuracy, Local Area Augmentation System - Benefits, Local Area Augmentation System - Drawbacks, Local Area Augmentation System - Variations, Local Area Augmentation System - Future, Local Area Augmentation System - References, Local Area Augmentation System - External links

Read more here: » Local Area Augmentation System: Encyclopedia II - Local Area Augmentation System - Drawbacks

One of the primary benefits of LAAS is that a single installation at a major airport can be used for multiple precision approaches within the local area. For example, if Chicago O'Hare has 12 runway ends each with a separate ILS, all 12 ILS facilities can be replaced with a single LAAS system. This represents a significant cost savings in maintenance and upkeep of the existing ILS equipment. Another benefit is the potential for approaches that are not straight in. A GPS with LAAS capability can guide an aircraft on any approach necessary to avoid obstacles o ...

See also:

Local Area Augmentation System, Local Area Augmentation System - History, Local Area Augmentation System - Operation, Local Area Augmentation System - Accuracy, Local Area Augmentation System - Benefits, Local Area Augmentation System - Drawbacks, Local Area Augmentation System - Variations, Local Area Augmentation System - Future, Local Area Augmentation System - References, Local Area Augmentation System - External links

Read more here: » Local Area Augmentation System: Encyclopedia II - Local Area Augmentation System - Benefits

Local reference receivers are located around an airport at precisely surveyed locations. The signal received from the GPS constellation is compared to the surveyed location then sent to a central location at an airport. This data is used to formulate a correction message which is then transmitted to users via a VHF data link. A receiver on the aircraft then uses this information to correct the GPS signals it receives. This information is u ...

See also:

Local Area Augmentation System, Local Area Augmentation System - History, Local Area Augmentation System - Operation, Local Area Augmentation System - Accuracy, Local Area Augmentation System - Benefits, Local Area Augmentation System - Drawbacks, Local Area Augmentation System - Variations, Local Area Augmentation System - Future, Local Area Augmentation System - References, Local Area Augmentation System - External links

Read more here: » Local Area Augmentation System: Encyclopedia II - Local Area Augmentation System - Operation

Surveying techniques have existed throughout much of recorded history. In Ancient Egypt, when the Nile River overflowed its banks and washed out farm boundaries, boundaries were re-established through the application of simple geometry. The nearly perfect squareness and north-south orientation of the Great Pyramid of Giza, built c. 2700 BC, affirm the ancient Egyptians' command of surveying. The Egyptian land register (3000 BC). In Rome, the tax register of conquered lands(300 AD). In England, The Domesday Book ...

See also:

Surveying, Surveying - Method, Surveying - Origins, Surveying - Types of surveys, Surveying - Surveying as a career, Surveying - Famous surveyors

Read more here: » Surveying: Encyclopedia II - Surveying - Origins

Theoretically a TACAN should provide a nine-fold increase in accuracy compared to a VOR but operational use has shown only a 1.5 to 2 fold increase. Accuracy of the 135 Hz azimuth component is ±1° or ±63 m at 3.47 km.[1] Accuracy of the DME portion is 185 m (±0.1 nm}.^{See also:}

TACAN, TACAN - Operation, TACAN - Accuracy, TACAN - Benefits, TACAN - Drawbacks, TACAN - Future, TACAN - References, TACAN - External links

Read more here: » TACAN: Encyclopedia II - TACAN - Accuracy

The basic principles of surveying have changed little over the ages, but the tools used by surveyors have evolved tremendously. Engineering, especially civil engineering, depends heavily on the surveyor. Whenever there are roads, dams, retaining walls, bridges or residential areas to be built, surveyors are involved. They determine the boundaries of private property and the boundaries of various lines of political divisions. They also provide advice and data for geographical information systems (GIS), computer databases ...

See also:

Surveying, Surveying - Method, Surveying - Origins, Surveying - Types of surveys, Surveying - Surveying as a career, Surveying - Famous surveyors

Read more here: » Surveying: Encyclopedia II - Surveying - Surveying as a career

The Defense Advanced Research Projects Agency (DARPA) is an agency of the United States Department of Defense responsible for the development of new technology for use by the military. DARPA was responsible for funding development of many technologies which have had a major impact on the world, including computer networking (starting with the ARPANET, which eventually grew into the Internet), as well as NLS, which was both the first hypertext system, and ...

Including:

• Defense Advanced Research Projects Agency - DARPA's Mission
• Defense Advanced Research Projects Agency - History
• Defense Advanced Research Projects Agency - Current Organization
• Defense Advanced Research Projects Agency - Controversy
• Defense Advanced Research Projects Agency - ARPA and DARPA in culture

Read more here: » Defense Advanced Research Projects Agency: Encyclopedia - Defense Advanced Research Projects Agency

2 SOPS was originally constituted as the 2d Surveillance Squadron (Sensor) and activated on 16 January 1962 under North American Air Defense Command (NORAD) at Ent Air Force Base. It was then organized on 1 February 1962 under the 9th Aerospace Defense Division, under which it operated SPACETRACK, the USAF globe-spanning space surveillance network, from 1962 through 1967. The squadron was discontinued and inactivated on 1 January 1967. Redesignated 2d Satellite Control Squadron on 16 July 1985 under the 2d Space Wing at Schriever AFB. Activated on 1 October 1985. Redesignated ...

See also:

2d Space Operations Squadron, 2d Space Operations Squadron - Chain of command, 2d Space Operations Squadron - History, 2d Space Operations Squadron - Decorations, 2d Space Operations Squadron - Emblem description

Read more here: » 2d Space Operations Squadron: Encyclopedia II - 2d Space Operations Squadron - History

Air Force Space Command - Numbered Air Forces. Air Force Space Command has two numbered air forces. The Fourteenth Air Force provides space warfighting forces to U.S. Strategic Command, and is located at Vandenberg AFB, California. They manage the generation and employment of space forces to support U.S. Strategic Command and North American Aerospace Defense Command (NORAD) operational plans and missions. The Twentieth Air Force is located at F.E. Warren AFB, Wyoming and maintains AFSPC's ICBM weapon systems in support of U.S. Strategic Command war plans. ...

See also:

Air Force Space Command, Air Force Space Command - Mission, Air Force Space Command - People, Air Force Space Command - Organization, Air Force Space Command - Numbered Air Forces, Air Force Space Command - Direct Reporting Units, Air Force Space Command - Locations, Air Force Space Command - Space capabilities, Air Force Space Command - Resources, Air Force Space Command - History, Air Force Space Command - Point of contact, Air Force Space Command - Trivia

Read more here: » Air Force Space Command: Encyclopedia II - Air Force Space Command - Organization

1989 - January. January 7 - Last day of the Showa period due to the death of Emperor Hirohito(aka Emperor Showa after his death) in Japan. Akihito became Emperor of Japan, and the Heisei period had begun from the following day. January 8 - the Kegworth Air Disaster - A British Midland Boeing 737 crashes on approach to East Midlands Airport - 44 dead January 16–18 - Race riots in Overtown, Miami January 10 - Cuban troops begin withdrawing from Angola January 10 - Assista ...

See also:

1989, 1989 - Events, 1989 - January, 1989 - February, 1989 - March, 1989 - April, 1989 - May, 1989 - June, 1989 - July, 1989 - August, 1989 - September, 1989 - October, 1989 - November, 1989 - December, 1989 - Unknown Dates, 1989 - Births, 1989 - Deaths, 1989 - January, 1989 - February, 1989 - March, 1989 - April, 1989 - May, 1989 - June, 1989 - July, 1989 - August, 1989 - September, 1989 - October, 1989 - November, 1989 - December, 1989 - Nobel Prizes, 1989 - Templeton Prize, 1989 - Right Livelihood Award

Read more here: » 1989: Encyclopedia II - 1989 - Events

In the 1930s German radio engineers developed a new system, called the "Ultrakurzwellen-Landefunkfeuer" (LFF), or simply "Leitstrahl" (guiding beam) but referred to outside Germany as Lorenz, the name of the company manufacturing the equipments. In Lorentz two signals were broadcast on the same frequencies from highly directional antennas with beams a few degrees wide. One was pointed slightly to the left of the other, with a small angle in the middle where they overlapped. The signals were chosen as dots and dashes, tim ...

See also:

Radio navigation, Radio navigation - Lorenz, Radio navigation - VOR, Radio navigation - GEE, Radio navigation - LORAN, Radio navigation - OMEGA and Alpha, Radio navigation - GPS

Read more here: » Radio navigation: Encyclopedia II - Radio navigation - Lorenz

A-10 Thunderbolt II - Features. The A-10/OA-10 has excellent maneuverability at low speeds and altitude, thanks to wide, straight wings. These also allow short takeoffs and landings, permitting operations from airfields near front lines. The plane can loiter for extended periods of time and operate under 1,000 foot (300 m) ceilings with 1.5-mile (2.4 km) visibility. It can fly at a relatively slow speed of 200 mph (320 km/h), which makes it better at ground-attack than fast fighter-bombers, which often have ...

See also:

A-10 Thunderbolt II, A-10 Thunderbolt II - Origins, A-10 Thunderbolt II - Description, A-10 Thunderbolt II - Features, A-10 Thunderbolt II - Criticisms, A-10 Thunderbolt II - Operational service, A-10 Thunderbolt II - Nicknames, A-10 Thunderbolt II - Trivia, A-10 Thunderbolt II - Specifications A-10 Thunderbolt II, A-10 Thunderbolt II - Dimensions, A-10 Thunderbolt II - Powerplant, A-10 Thunderbolt II - Weights, A-10 Thunderbolt II - Take-off weights, A-10 Thunderbolt II - Performance, A-10 Thunderbolt II - Combat radii, A-10 Thunderbolt II - Armament, A-10 Thunderbolt II - Related content, A-10 Thunderbolt II - Designation sequence, A-10 Thunderbolt II - Related development, A-10 Thunderbolt II - Similar aircraft, A-10 Thunderbolt II - Related lists, A-10 Thunderbolt II - External links

Read more here: » A-10 Thunderbolt II: Encyclopedia II - A-10 Thunderbolt II - Description

The A-10/OA-10 has excellent maneuverability at low speeds and altitude, thanks to wide, straight wings. These also allow short takeoffs and landings, permitting operations from airfields near front lines. The plane can loiter for extended periods of time and operate under 1,000 foot (300 m) ceilings with 1.5-mile (2.4 km) visibility. It can fly at a relatively slow speed of 200 mph (320 km/h), which makes it better at ground-attack than fast fighter-bombers, which often have ...

See also:

A-10 Thunderbolt II, A-10 Thunderbolt II - Description, A-10 Thunderbolt II - Operational service, A-10 Thunderbolt II - Specifications A-10 Thunderbolt II, A-10 Thunderbolt II - Dimensions, A-10 Thunderbolt II - Powerplant, A-10 Thunderbolt II - Weights, A-10 Thunderbolt II - Take-off weights, A-10 Thunderbolt II - Performance, A-10 Thunderbolt II - Combat radii, A-10 Thunderbolt II - Armament, A-10 Thunderbolt II - Television films and video games, A-10 Thunderbolt II - Related content, A-10 Thunderbolt II - Designation sequence, A-10 Thunderbolt II - Related development, A-10 Thunderbolt II - Similar aircraft, A-10 Thunderbolt II - Related lists, A-10 Thunderbolt II - External links

Read more here: » A-10 Thunderbolt II: Encyclopedia II - A-10 Thunderbolt II - Description

To extend this definition far from land means comparing the local height of the mean sea surface with a "level" reference surface, or datum, called the geoid. In a state of rest or absence of external forces, the mean sea level would coincide with this geoid surface, being an equipotential surface of the Earth's gravity field. In reality, due to currents, air pressure variations, temperature and salinity variations, etc., this does not occur, not even as a long term average. The location-dependent, but persistent in time, separation between mean sea level and the geoid is referred to as (stationary) sea su ...

See also:

Sea level, Sea level - Definition, Sea level - Measurement, Sea level - Difficulties in utilization, Sea level - Changes through geologic time

Read more here: » Sea level: Encyclopedia II - Sea level - Difficulties in utilization

The AGM-130 is a powered air-to-surface missile designed for strikes at long range against various targets. It is essentially a powered version of the GBU-15 bomb, with the rocket motor increasing the launch range and so giving the launch aircraft protection from whatever defences may protect the target. Two can be carried by the F-15E. The weapon utilises inertial navigation aided by the Global Positioning System (GPS). It can be retargeted in flight; the guidance head of the weapon provides a visual image of the target to the launch ...

See also:

AGM-130, AGM-130 - Overview, AGM-130 - Variants, AGM-130 - Specifications

Read more here: » AGM-130: Encyclopedia II - AGM-130 - Overview

AGM-86 - AGM-86A/B. In February 1974, the U.S. Air Force entered into contract to develop and flight-test the prototype or proof-of-concept vehicle AGM-86A air-launched cruise missile, which was slightly smaller than the later B and C models. The 86A model did not go into production. Instead, in January 1977, the Air Force began full-scale development of the AGM-86B, which greatly enhanced the B-52's capabilities and helped th ...

See also:

AGM-86, AGM-86 - Features, AGM-86 - Background, AGM-86 - AGM-86A/B, AGM-86 - AGM-86C, AGM-86 - Other characteristics, AGM-86 - External link, AGM-86 - Source

Read more here: » AGM-86: Encyclopedia II - AGM-86 - Background