Polarization is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. A simple example of a polarized transverse wave is vibrations traveling along a taut string. Depending on how the string is plucked, the vibrations can be in a vertical direction, horizontal direction, or at any angle perpendicular to the string. In contrast, in longitudinal waves, such as sound waves in a liquid or gas, the displacement of the particles in the oscillation is always in the direction of propagation, so these waves do not exhibit polarization. Transverse waves that exhibit polarization include electromagnetic waves such as light and radio waves, gravitational waves, transverse sound waves in solids. In some types of transverse waves, the wave displacement is limited to a single direction, so these do not exhibit polarization. An electromagnetic wave such as light consists of a coupled oscillating electric field and magnetic field which are always perpendicular.
In linear polarization, the fields oscillate in a single direction. In circular or elliptical polarization, the fields rotate at a constant rate in a plane as the wave travels; the rotation can have two possible directions. Light or other electromagnetic radiation from many sources, such as the sun and incandescent lamps, consists of short wave trains with an equal mixture of polarizations. Polarized light can be produced by passing unpolarized light through a polarizer, which allows waves of only one polarization to pass through; the most common optical materials are isotropic and do not affect the polarization of light passing through them. Some of these are used to make polarizing filters. Light is partially polarized when it reflects from a surface. According to quantum mechanics, electromagnetic waves can be viewed as streams of particles called photons; when viewed in this way, the polarization of an electromagnetic wave is determined by a quantum mechanical property of photons called their spin.
A photon has one of two possible spins: it can either spin in a right hand sense or a left hand sense about its direction of travel. Circularly polarized electromagnetic waves are composed of photons with only one type of spin, either right- or left-hand. Linearly polarized waves consist of photons that are in a superposition of right and left circularly polarized states, with equal amplitude and phases synchronized to give oscillation in a plane. Polarization is an important parameter in areas of science dealing with transverse waves, such as optics, seismology and microwaves. Impacted are technologies such as lasers and optical fiber telecommunications, radar. Most sources of light are classified as incoherent and unpolarized because they consist of a random mixture of waves having different spatial characteristics, frequencies and polarization states. However, for understanding electromagnetic waves and polarization in particular, it is easiest to just consider coherent plane waves. Characterizing an optical system in relation to a plane wave with those given parameters can be used to predict its response to a more general case, since a wave with any specified spatial structure can be decomposed into a combination of plane waves.
And incoherent states can be modeled stochastically as a weighted combination of such uncorrelated waves with some distribution of frequencies and polarizations. Electromagnetic waves, traveling in free space or another homogeneous isotropic non-attenuating medium, are properly described as transverse waves, meaning that a plane wave's electric field vector E and magnetic field H are in directions perpendicular to the direction of wave propagation. By convention, the "polarization" direction of an electromagnetic wave is given by its electric field vector. Considering a monochromatic plane wave of optical frequency f, let us take the direction of propagation as the z axis. Being a transverse wave the E and H fields must contain components only in the x and y directions whereas Ez = Hz = 0. Using complex notation, the instantaneous physical electric and magnetic fields are given by the real parts of the complex quantities occurring in the following equations; as a function of time t and spatial position z these complex fields can be written as: E → =
WMMO is a commercial FM radio station in Orlando, Florida. It is owned by the Cox Media Group, airs a classic hits radio format that leans toward classic rock. Most songs heard on WMMO were hits from the 1980s and 90s, on both the Top 40 charts and on the Album Rock charts. WMMO's studios and offices are located in Orlando on North John Young Parkway; the transmitter tower is off Park Hamilton Boulevard in Pine Hills. The site is shared with AM 990 WDYZ, owned by the Salem Media Group. In the late 1980s, the Federal Communications Commission awarded a construction permit to build a new FM radio station in Orlando to the Urban Broadcasting Corporation; the call sign WURG was granted. The station signed on the air on August 19, 1990, it was owned by Radio Orlando and it aired a unique format with a large library, a mix of soft rock, adult album alternative and classic rock. Its creators sought to bring back a listening experience similar to early FM rock stations of the late 1960s and 1970s, focusing on music rather than contests and promotions.
A popular slogan in its early days was, "if you want to win money, play the lottery." WMMO used a wide ranging playlist of songs from many genres. Its library stretched from the mid-1960s to current releases, unlike many stations that focus on small slices of music from specific genres. WMMO made a promise to always identify songs by title and artist, to never talk over the music. "We love the music as much as you do" was a slogan the station used during this era. The call letters used at first were WEZO, but after a month on the air, the call sign switched to WMMO. The station derives its call letters from WMMS in Cleveland; the founding programmer and chief engineer, Cary Pall, was a fan of WMMS, secured the call sign to honor the legendary rock station though WMMO's format was not as rock-oriented. WMMO was one of only two radio stations in the world broadcasting from a enclosed transmit antenna. WMMO was located at the top of Orlando's tallest building, its effective radiated power was 38,000 watts and its antenna was only 439 feet in height above average terrain, while most of the top FM stations in Orlando broadcast at 100,000 watts on towers 1,500 feet or taller.
The station's coverage area was limited due to a station in Fort Pierce, 98.7 WKGR. WMMO's signal could not interfere with WKGR, only one dial position away. Around 2015, WKGR moved about 20 miles south near West Palm Beach. So WMMO was able to increase its antenna height slightly. In 1991, WMMO was bought by Granam Communications for $8.15 million. The station continued its unique playlist of Adult Album Rock and Classic Rock. In 1997, Granam Communications was acquired by Infinity Broadcasting part of CBS Radio. Infinity spun off AM 990 WHOO, FM 96.5 WHTQ and WMMO to Cox Radio, so Infinity could acquire 105.9 WCKG in Chicago. Cox had plans move WMMO's transmitter to WHTQ's former tower in Pine Hills for better coverage, but a breakdown in negotiations with WHTQ's former owner forced WMMO's transmitter to remain at the SunBank Center/SunTrust Center for several more years. In 2008, longtime personalities Jerry Steffen and Jay Francisco were let go. Steffen was at Francisco for 14 years. Francisco was rehired in 2011 for several more years.
In 2011, longtime morning host Shawn Burke was released after 12 years at WMMO. In 2012, the station abandoned its previous practice of listing the names of all the songs and artists played; the music became more rock-oriented during these years. In July 2015, WMMO began referring to itself as a classic hits station in an effort to compete with CBS Radio classic hits outlet 105.9 WOCL. Mornings -- Denise Ryan Middays -- Joe Rock Afternoons -- Hildi Evenings -- A. J. Maguire 98.9 WMMO Query the FCC's FM station database for WMMO Radio-Locator information on WMMO Query Nielsen Audio's FM station database for WMMO
Frequency is the number of occurrences of a repeating event per unit of time. It is referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency; the period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example: if a newborn baby's heart beats at a frequency of 120 times a minute, its period—the time interval between beats—is half a second. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals, radio waves, light. For cyclical processes, such as rotation, oscillations, or waves, frequency is defined as a number of cycles per unit time. In physics and engineering disciplines, such as optics and radio, frequency is denoted by a Latin letter f or by the Greek letter ν or ν; the relation between the frequency and the period T of a repeating event or oscillation is given by f = 1 T.
The SI derived unit of frequency is the hertz, named after the German physicist Heinrich Hertz. One hertz means. If a TV has a refresh rate of 1 hertz the TV's screen will change its picture once a second. A previous name for this unit was cycles per second; the SI unit for period is the second. A traditional unit of measure used with rotating mechanical devices is revolutions per minute, abbreviated r/min or rpm. 60 rpm equals one hertz. As a matter of convenience and slower waves, such as ocean surface waves, tend to be described by wave period rather than frequency. Short and fast waves, like audio and radio, are described by their frequency instead of period; these used conversions are listed below: Angular frequency denoted by the Greek letter ω, is defined as the rate of change of angular displacement, θ, or the rate of change of the phase of a sinusoidal waveform, or as the rate of change of the argument to the sine function: y = sin = sin = sin d θ d t = ω = 2 π f Angular frequency is measured in radians per second but, for discrete-time signals, can be expressed as radians per sampling interval, a dimensionless quantity.
Angular frequency is larger than regular frequency by a factor of 2π. Spatial frequency is analogous to temporal frequency, but the time axis is replaced by one or more spatial displacement axes. E.g.: y = sin = sin d θ d x = k Wavenumber, k, is the spatial frequency analogue of angular temporal frequency and is measured in radians per meter. In the case of more than one spatial dimension, wavenumber is a vector quantity. For periodic waves in nondispersive media, frequency has an inverse relationship to the wavelength, λ. In dispersive media, the frequency f of a sinusoidal wave is equal to the phase velocity v of the wave divided by the wavelength λ of the wave: f = v λ. In the special case of electromagnetic waves moving through a vacuum v = c, where c is the speed of light in a vacuum, this expression becomes: f = c λ; when waves from a monochrome source travel from one medium to another, their frequency remains the same—only their wavelength and speed change. Measurement of frequency can done in the following ways, Calculating the frequency of a repeating event is accomplished by counting the number of times that event occurs within a specific time period dividing the count by the length of the time period.
For example, if 71 events occur within 15 seconds the frequency is: f = 71 15 s ≈ 4.73 Hz If the number of counts is not large, it is more accurate to measure the time interval for a predetermined number of occurrences, rather than the number of occurrences within a specified time. The latter method introduces a random error into the count of between zero and one count, so on average half a count; this is called gating error and causes an average error in the calculated frequency of Δ f = 1 2 T
Central Florida is a region of the Southern U. S. state of Florida. Different sources give different definitions for the region, but as its name implies it is said to comprise the central part of the state, including the Orlando area, it is one of Florida's three directional regions, along with South Florida. It includes the following counties: Brevard, Hardee, Hillsborough, Indian River, Manatee, Orange, Pasco, Polk, Seminole and Volusia. Like many vernacular regions, Central Florida's boundaries are not official or consistent, are defined differently by different sources. A 2007 study of Florida's regions by geographers Ary Lamme and Raymond K. Oldakowski found that Floridians surveyed identified Central Florida as comprising a large swath of peninsular Florida; this area encompassed the interior, including the Orlando metropolitan area, coastal stretches from the Big Bend south to the Tampa Bay Area in the west and from Daytona Beach south to Martin County in the east. In addition, North Central Florida has emerged as a vernacular region representing the interior area in the northern part of the state.
Central Florida is one of Florida's three most common directional regions, the others being North Florida and South Florida. Lamme and Oldakowski note that the directional region is more used in the interior areas rather than on the coast. In fact, while coastal areas have their own regional vernacular identities such as the Space Coast and the Nature Coast, no vernacular regions were reported on the interior of the state other than Central Florida. Enterprise Florida, the state's economic development agency, identifies "Central Florida" as one of eight economic regions used by the agency and other state and outside entities, including the Florida Department of Transportation; this definition covers much of the same area as in Lamme and Oldakowski's survey, with some exceptions. It excludes North Central Florida, as well as the southern coastal counties; the Central region includes the Orlando metropolitan area and Sumter Counties in the interior, Volusia and Brevard Counties on the coast. The central cities of both metropolitan areas are in close proximity, as a result, their two metropolitan areas blend together in the area of Lakeland to make up a larger contiguous population center referred to as the I-4 corridor.
This is a population concentration that stretches from Tampa Bay on the west coast to Daytona Beach and Cape Canaveral on the east coast of the state. With the exception of hill terrain in southern Lake County, Hernando County, Pasco County and Polk County, Central Florida is flatland with significant amounts of open space and over 1,500 lakes and ponds. There is a mixture of wetlands, Oak and Pine forests, pastures and coastline. Major rivers include the St. Johns River, the Ocklawaha River, the Halifax River, the Econlockhatchee River. Major lakes include Lake Apopka, Lake Tohopekaliga, East Lake Tohopekaliga, Lake Louisa, Lake Monroe, Lake Jessup, the Butler Chain of Lakes. There are over 100 miles of coastline in Central Florida along the Atlantic Coast. Major beaches include Canaveral National Seashore, New Smyrna Beach, Daytona Beach, Cocoa Beach, Indialantic Beach near Melbourne. Hurricanes are a threat to the coastal cities as evident by the 2004 hurricane season, which brought three major hurricanes to the Central Florida area: Charley and Frances.
Winters are dry and temperate with the average winter high temperature in Orlando being 72 °F. Summers are hot and humid with high temperatures averaging 92 °F. Peak summer heat arrives in early June and continues to early October; the combination of high temperatures, high humidity, opposing sea breezes from both the Gulf and Atlantic coasts, results in significant thunderstorm activity from June to September for the interior counties. Central Florida records more lightning strikes per area than any other region in Florida, Florida records more lightning strikes than any other state in the USA; as a result and more Central Florida, is referred to as the "Thunderstorm capital of the USA", or "Lightning Alley". These severe thunderstorms make Central Florida prone to many tornadoes. However, they are small, short lived, always rated as EF0 or EF1 size storms. At the end of the Civil War most of Central Florida was barely-inhabitable wetlands, it took a major drainage project financed by Philadelphia businessman Hamilton Disston in the 1880s to make the land available for settlement.
Sanford was incorporated in 1877 as port city at the intersection of Lake Monroe and the St. Johns River, it was envisioned as a transportation center, the city's founder, Henry S. Sanford, nicknamed it "the Gate City of South Florida", it became a hub for shipping agricultural products, which earned the city another nickname, "Celery City". Kissimmee boomed in the 1880s, it was the headquarters of Hamilton Disston's drainage company, The city was an important regional steamship port, owing that status to its location on Lake Tohopekaliga. The expansion of the railroads into Central Florida eliminated the need for Kissimmee's steamship industry; the Great Freeze of 1894-95 ruined citrus crops which had a detrimental ripple effect on the economy. The hard-packed sand of Volusia County's beaches lent itself to auto races beginning in 1903, before paved roads were common, leading to the area's reputation for cars and racing. Ormond Beach was a popular spot for those who liked fast cars after the
Cox Enterprises, Inc. is a held global conglomerate headquartered in Atlanta, Georgia with 55,000 employees and $21 billion in total revenue. Its major operating subsidiaries are Cox Automotive and Cox Media Group; the company's major national brands include AutoTrader, Kelley Blue Book, Cox Homelife and more. Through Cox Automotive, the company's international operations stretch across Asia, Australia and Latin America. Cox Enterprises is led by Alexander C. Taylor, a fourth-generation Cox family member and great-grandson of founder James M. Cox. James M. Cox's grandson, James C. Kennedy and other members of the Cox family are on the company's board of directors; the company was founded in Dayton, Ohio by James M. Cox, who purchased the Dayton Daily News in 1898. Cox became the Democratic Party candidate for president of the United States in the presidential election of 1920, running unsuccessfully on a ticket that included Franklin D. Roosevelt as the vice presidential candidate; the company is well-known for its ownership of Bing Crosby Productions and Rysher Entertainment the two companies merged in 1993.
Cox shut down the company and sold its distribution assets to Viacom and now they are a part of the archives of CBS Television Distribution as well as the back catalog of Paramount Pictures. James M. Cox Jr. became the company's chairman after his father died in 1957. The family and company were highlighted in a 2015 Forbes article called "This Billionaire Knows the Secret to Saving a Family Business". Cox Jr. died in his sisters inherited ownership. Barbara Cox's second husband Garner Anthony and son by her first husband James Cox Kennedy have served as chairman, in 2018 Anne Cox's grandson Alexander C. Taylor became chief executive officer and president. Cox Communications is the third-largest U. S. cable company, serving 6 million residences and businesses. It provides advanced digital video, Internet and home security and automation services over tis own nationwide IP network. Cox Communications formed an alliance with the Cleveland Clinic to take Healthcare to the home in February 2015; the company has been deploying residential gigabit internet service.
Cox Media Group is an integrated broadcasting, direct marketing and digital media company. Its properties include broadcast television and radio stations, daily newspapers runs metro newspapers, non-daily publications, has more than 100 digital services. In 2019 Cox Enterprises reached an agreement with Apollo Funds to buy majority interest in Cox Media Group's broadcast television stations, including the company's radio, newspaper and TV properties in Ohio. Cox will maintain a minority stake and will join the Apollo Funds in forming a new company to operate these stations. Cox Media Group is involved in automated and programmatic sales through Videa. Cox Automotive is a provider of vehicle remarketing services and digital marketing and software solutions for automotive dealers and consumers, its mission is to "make buying, selling and using cars easier for everyone." Cox Automotive brands include Manheim, Clutch Technologies, Dealer-Auction Ltd, AutoTrader, Kelley Blue Book, vAuto, Dealer.com, NextGear Capital, Vinsolutions and a host of global businesses and brands serving auto dealers and financial institutions.
In June 2015, Cox Automotive announced the biggest vendor acquisition in the history of auto retailing by agreeing to pay $4 billion in cash for dealer software giant Dealertrack Technologies Inc. The acquisition closed in October 2015. Official website Media related to Cox Enterprises at Wikimedia Commons
WPYO is a radio station licensed to Maitland, Florida. Owned by Cox Radio, it broadcasts a contemporary hit radio format serving the Greater Orlando area, it shares studios with its sister stations on North John Young Parkway in Orlando. Prior to Cox Enterprises buying the station in 1999, the station was WTLN-FM, a contemporary Christian outlet, but after the sale that same year, on January 15, it flipped to Dance Top 40 as 95.3 Party, became a success in the market with its mix of dance and hip-hop music. By 2004, the station had shifted to a hip-hop-driven direction, rebranded as rhythmic contemporary Power 95.3, restoring the format to Orlando since the flip of WJHM to urban contemporary in the 1990s. On April 27, 2018, WPYO flipped to CHR, maintaining some of its airstaff; the change came in response to WQMP's recent flip to alternative rock, which gave WXXL a monopoly in the format within the Orlando market. Official website Query the FCC's FM station database for WPYO Radio-Locator information on WPYO Query Nielsen Audio's FM station database for WPYO
Radio broadcasting is transmission by radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both; the signal types can be digital audio. The earliest radio stations did not carry audio. For audio broadcasts to be possible, electronic detection and amplification devices had to be incorporated; the thermionic valve was invented in 1904 by the English physicist John Ambrose Fleming. He developed a device he called an "oscillation valve"; the heated filament, or cathode, was capable of thermionic emission of electrons that would flow to the plate when it was at a higher voltage. Electrons, could not pass in the reverse direction because the plate was not heated and thus not capable of thermionic emission of electrons. Known as the Fleming valve, it could be used as a rectifier of alternating current and as a radio wave detector; this improved the crystal set which rectified the radio signal using an early solid-state diode based on a crystal and a so-called cat's whisker.
However, what was still required was an amplifier. The triode was patented on March 4, 1906, by the Austrian Robert von Lieben independent from that, on October 25, 1906, Lee De Forest patented his three-element Audion, it wasn't put to practical use until 1912 when its amplifying ability became recognized by researchers. By about 1920, valve technology had matured to the point where radio broadcasting was becoming viable. However, an early audio transmission that could be termed a broadcast may have occurred on Christmas Eve in 1906 by Reginald Fessenden, although this is disputed. While many early experimenters attempted to create systems similar to radiotelephone devices by which only two parties were meant to communicate, there were others who intended to transmit to larger audiences. Charles Herrold started broadcasting in California in 1909 and was carrying audio by the next year.. In The Hague, the Netherlands, PCGG started broadcasting on November 6, 1919, making it, arguably the first commercial broadcasting station.
In 1916, Frank Conrad, an electrical engineer employed at the Westinghouse Electric Corporation, began broadcasting from his Wilkinsburg, Pennsylvania garage with the call letters 8XK. The station was moved to the top of the Westinghouse factory building in East Pittsburgh, Pennsylvania. Westinghouse relaunched the station as KDKA on November 2, 1920, as the first commercially licensed radio station in America; the commercial broadcasting designation came from the type of broadcast license. The first licensed broadcast in the United States came from KDKA itself: the results of the Harding/Cox Presidential Election; the Montreal station that became CFCF began broadcast programming on May 20, 1920, the Detroit station that became WWJ began program broadcasts beginning on August 20, 1920, although neither held a license at the time. In 1920, wireless broadcasts for entertainment began in the UK from the Marconi Research Centre 2MT at Writtle near Chelmsford, England. A famous broadcast from Marconi's New Street Works factory in Chelmsford was made by the famous soprano Dame Nellie Melba on 15 June 1920, where she sang two arias and her famous trill.
She was the first artist of international renown to participate in direct radio broadcasts. The 2MT station began to broadcast regular entertainment in 1922; the BBC was amalgamated in 1922 and received a Royal Charter in 1926, making it the first national broadcaster in the world, followed by Czech Radio and other European broadcasters in 1923. Radio Argentina began scheduled transmissions from the Teatro Coliseo in Buenos Aires on August 27, 1920, making its own priority claim; the station got its license on November 19, 1923. The delay was due to the lack of official Argentine licensing procedures before that date; this station continued regular broadcasting of entertainment and cultural fare for several decades. Radio in education soon followed and colleges across the U. S. began adding radio broadcasting courses to their curricula. Curry College in Milton, Massachusetts introduced one of the first broadcasting majors in 1932 when the college teamed up with WLOE in Boston to have students broadcast programs.
Broadcasting service is – according to Article 1.38 of the International Telecommunication Union´s Radio Regulations – defined as «A radiocommunication service in which the transmission are intended for direct reception by the general public. This service may include sound transmissions, television transmissions or other types of transmission.» Definitions identical to those contained in the Annexes to the Constitution and Convention of the International Telecommunication Union are marked "" or "" respectively. A radio broadcasting station is associated with wireless transmission, though in practice broadcasting transmission take place using both wires and radio waves; the point of this is that anyone with the appropriate receiving technology can receive the broadcast. In line to ITU Radio Regulations each broadcasting station shall be classified by the service in which it operates permanently or temporarily. Broadcasting by radio takes several forms; these include FM stations. There are several subtypes, namely commercial broadcasting, non-commercial educational public broadcasting and non-profit varieties as well as community radio, student-run campus radio stations, and