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Clock Position
A clock position, or clock bearing, is the direction of an object observed from a vehicle, typically a vessel or an aircraft, relative to the orientation of the vehicle to the observer. The vehicle must be considered to have a front, a back, a left side and a right side. These quarters may have specialized names, such as bow and stern for a vessel, or nose and tail for an aircraft. The observer then measures or observes the angle made by the intersection of the line of sight to the longitudinal axis, the dimension of length, of the vessel, using the clock analogy. In this analogy, the observer imagines the vessel located on a horizontal clock face with the front at 12:00. Neglecting the length of the vessel, and presuming that he is at the bow, he observes the time number lying on the line of sight. For example, ''12 o'clock'' means ''directly ahead'', ''3 o'clock'' means ''directly to the right'', ''6 o'clock'' means ''directly behind'', and ''9 o'clock'' means ''directly to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Time
In modern usage, civil time refers to statutory time as designated by civilian authorities. Modern civil time is generally national standard time in a time zone at a UTC offset, fixed offset from Coordinated Universal Time (UTC), possibly adjusted by daylight saving time during part of the year. UTC is calculated by reference to atomic clocks and was adopted in 1972. Older systems use telescope observations. In traditional astronomical usage, civil time was mean solar time reckoned from midnight. Before 1925, the astronomical time 00:00:00 meant noon, twelve hours after the civil time 00:00:00 which meant midnight. HM Nautical Almanac Office in the United Kingdom used Greenwich Mean Time (GMT) for both conventions, leading to ambiguity, whereas the Nautical Almanac Office at the United States Naval Observatory used GMT for the pre-1925 convention and Greenwich Civil Time (GCT) for the post-1924 convention until 1952. In 1928, the International Astronomical Union introduced the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Rome
The history of Rome includes the history of the city of Rome as well as the civilisation of ancient Rome. Roman history has been influential on the modern world, especially in the history of the Catholic Church, and Roman law has influenced many modern legal systems. Roman history can be divided into the following periods: *Pre-historical and early Rome, covering Rome's earliest inhabitants and the legend of its founding by Romulus *The period of Etruscan dominance and the regal period, in which, according to tradition, Romulus was the first of seven kings *The Roman Republic, which commenced in 509 BC when kings were replaced with rule by elected magistrates. The period was marked by vast expansion of Roman territory. During the 5th century BC, Rome gained regional dominance in Latium. With the Punic Wars from 264 to 146 BC, ancient Rome gained dominance over the Western Mediterranean, displacing Carthage as the dominant regional power. *The Roman Empire followed the Republi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drift (navigation)
The term “set and drift” is used to describe external forces that affect a boat and keep it from following an intended course. To understand and calculate set and drift, one needs to first understand currents. Ocean currents are the horizontal movements of water from one location to another. The movement of water is impacted by: meteorological effects, wind, temperature differences, gravity, and on occasion earthquakes. Set is the current's direction, expressed in true degrees. Drift is the current's speed, which is usually measured in knots. “Leeway” refers to the amount of sidewards translation of a vessel drifting off of or away from the intended course of travel (with no correction or compensation by altering the heading of the vessel such as pointing her into the wind.) Ignoring set and drift can cause a mariner to get off their desired course, sometimes by hundreds of miles. A mariner needs to be able to steer the ship and compensate for the effects of set and drift ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heading (navigation)
In navigation, the heading of a vessel or aircraft is the compass direction in which the craft's bow or nose is pointed. Note that the heading may not necessarily be the direction that the vehicle actually travels, which is known as its '' course''. Any difference between the heading and course is due to the motion of the underlying medium, the air or water, or other effects like skidding or slipping. The difference is known as the ''drift'', and can be determined by the ''wind triangle''. At least seven ways to measure the heading of a vehicle have been described. Heading is typically based on cardinal directions, so 0° (or 360°) indicates a direction toward true north, 90° true east, 180° true south, and 270° true west. TVMDC TVMDC,AW is a mnemonic for converting from true heading, to magnetic and compass headings. TVMDC is a mnemonic initialism for true heading, variation, magnetic heading, deviation, compass heading, add westerly. The most common use of the TVMDC met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Track
A satellite ground track or satellite ground trace is the path on the surface of a planet directly below a satellite's trajectory. It is also known as a suborbital track or subsatellite track, and is the vertical projection of the satellite's orbit onto the surface of the Earth (or whatever body the satellite is orbiting). A satellite ground track may be thought of as a path along the Earth's surface that traces the movement of an imaginary line between the satellite and the center of the Earth. In other words, the ground track is the set of points at which the satellite will pass directly overhead, or cross the zenith, in the frame of reference of a ground observer.. The ground track of a satellite can take a number of different forms, depending on the values of the orbital elements, parameters that define the size, shape, and orientation of the satellite's orbit, although identification of the always reliant upon the recognition of the physical form that is in motion; This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aim Fig 4-1-1 Induced Error In Position Of Traffic
AIM or Aim may refer to: Computing * AIM alliance, an Apple-IBM-Motorola alliance * AIM (software), AOL Instant Messenger * Fortyfive, a Japanese software development company previously known as AIM Military * Abrams Integrated Management, an upgrade to the M1A1 model of the M1 Abrams tank (known as M1A1 AIM) * Airborne intercept missile, US DoD designation for air-to-air missiles such as AIM-7 Sparrow * Authoring Instructional Materials, US Navy training management system * Pistol Mitralieră model 1963/1965 (AIM, AIMS), Model 63, 65, 90 assault rifles * Pușcă Automată model 1986 (AIMS-74), Model 86 automatic rifle Music * "A.I.M.", single by the Cooper Temple Clause from '' Kick Up the Fire, and Let the Flames Break Loose'' * "AIM", song by Tyga from the album ''No Introduction'' * ''AIM'' (album), 2016 album by M.I.A. * Aim (musician), stage name of Andrew Turner, British musician, producer, and DJ of the 2000s * American Institute of Musicology, early music musi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Coordinate System
In mathematics, the polar coordinate system specifies a given point in a plane by using a distance and an angle as its two coordinates. These are *the point's distance from a reference point called the ''pole'', and *the point's direction from the pole relative to the direction of the ''polar axis'', a ray drawn from the pole. The distance from the pole is called the ''radial coordinate'', ''radial distance'' or simply ''radius'', and the angle is called the ''angular coordinate'', ''polar angle'', or ''azimuth''. The pole is analogous to the origin in a Cartesian coordinate system. Polar coordinates are most appropriate in any context where the phenomenon being considered is inherently tied to direction and length from a center point in a plane, such as spirals. Planar physical systems with bodies moving around a central point, or phenomena originating from a central point, are often simpler and more intuitive to model using polar coordinates. The polar coordinate system i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golf Swing
The golf swing is the action by which players hit the ball in the sport of golf. The golf swing is a complex motion involving the whole body; the technicalities of the swing are known as golf stroke mechanics. There are differing opinions on what constitutes a "good" golf swing. In ''Work and Power Analysis of the Golf Swing'', Nesbit and Serrano suggest the golf swing has been studied by scientists and mathematicians who have developed various equations to help explain the complexity of the swing. It is generally agreed that a successful and consistent golf swing requires precise timing and mechanics, from the grip and position of one's fingers, to the position and movement of the feet. At any moment of the swing, whether back-swing, downswing, or upswing, something can go wrong that will throw off the whole body and result in a mishit. The entire swing motion should move on a plane in a fluid manner. The plane can be characterized as horizontal or vertical. Complex motion The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammary Alveolus
A mammary alveolus (: alveoli, from Latin , "little cavity") is a small cavity or sac found in the mammary gland. Mammary alveoli are the site of milk production and storage in the mammary gland. Mammary alveoli cluster into groups called mammary lobules, and each breast may contain 15 to 20 of these lobules. The lobules drain milk through the lactiferous ducts out of the nipples. See also * Breastfeeding * Lactation Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The process ... References Breast anatomy {{anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Aviation Administration
The Federal Aviation Administration (FAA) is a Federal government of the United States, U.S. federal government agency within the United States Department of Transportation, U.S. Department of Transportation that regulates civil aviation in the United States and surrounding international waters. Its powers include air traffic control, certification of personnel and aircraft, setting standards for airports, and protection of U.S. assets during the launch or re-entry of commercial space vehicles. Powers over neighboring international waters were delegated to the FAA by authority of the International Civil Aviation Organization. The FAA was created in as the Federal Aviation Agency, replacing the Civil Aeronautics Administration (United States), Civil Aeronautics Administration (CAA). In 1967, the FAA became part of the newly formed U.S. Department of Transportation and was renamed the Federal Aviation Administration. Major functions The FAA's roles include: *Regulating U.S. co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
