Height above average terrain
Height above average terrain, or effective height above average terrain, is a measure of how high an antenna site is above the surrounding landscape. HAAT is used extensively in FM radio and television, as it is more important than effective radiated power in determining the range of broadcasts. For international coordination, it is measured in meters by the Federal Communications Commission in the United States, as Canada and Mexico have extensive border zones where stations can be received on either side of the international boundaries. Stations that want to increase above a certain HAAT must reduce their power accordingly, based on the maximum distance their station class is allowed to cover; the FCC procedure to calculate HAAT is: from the proposed or actual antenna site, either 12 or 16 radials were drawn, points at 2, 4, 6, 8, 10 miles radius along each radial were used. The entire radial graph could be rotated to achieve the best effect for the station; the altitude of the antenna site, minus the average altitude of all the specified points, is the HAAT.
This can create some unusual cases in mountainous regions—it is possible to have a negative number for HAAT. The FCC has divided the Contiguous United States into three zones for the determination of spacing between FM and TV stations using the same frequencies. FM and TV stations are assigned maximum ERP and HAAT values, depending on their assigned zones, to prevent co-channel interference; the FCC regulations for ERP and HAAT are listed under Title 47, Part 73 of the Code of Federal Regulations. Maximum HAAT: 150 metres Maximum ERP: 50 kilowatts Minimum co-channel separation: 241 km Maximum HAAT: 600 metres Maximum ERP: 100 kilowatts Minimum co-channel separation: 290 km. In all zones, maximum ERP for analog TV transmitters is. In addition, Zone I-A consists of all of California south of 40° north latitude, Puerto Rico and the U. S. Virgin Islands. Zones I and I-A have the most "grandfathered" overpowered stations, which are allowed the same extended coverage areas that they had before the zones were established.
One of the most powerful of these stations is WBCT in Grand Rapids, which operates at 320,000 watts and 238 meters HAAT. Zone III consists of all of Florida and the areas of Alabama, Louisiana and Texas within 241.4 kilometers of the Gulf of Mexico. Zone II is all the rest of the Continental United States and Hawaii. Above mean sea level Above ground level Canadian Radio-television and Telecommunications Commission List of broadcast station classes United States Federal Communications Commission 47 CFR Part 73 Index FCC: Mass Media Calculated Contours FCC: HAAT Calculator "Superpower" Grandfathered FM stations
Back Stabbers (song)
"Back Stabbers" is a 1972 song by the O'Jays. Released from the hit album of the same name, the song spent one week at number one on the Hot Soul Singles chart, it was successful on the pop charts, peaking at number three on the Billboard Hot 100 singles chart in October 1972. The narrator in "Back Stabbers" warns men about their male "friends" who smile to their faces, but are secretly planning to steal their wives or girlfriends, it was inspired by an earlier hit with a similar theme, the Undisputed Truth's "Smiling Faces Sometimes", the chorus of, quoted at the end of the song. It was part of the soundtrack for the 1977 movie Looking for Mr. Goodbar. "Back Stabbers" is the second single from the 1979 album Love Explosion by Tina Turner. The song, along with the other two singles released from Love Explosion, was disco-oriented and was overlooked by audiences both in Europe and the United States due to the so-called "anti-disco backlash" at the time. "Back Stabbers" was covered by Stephen Cummings in 1983.
MFSB's 1973 debut album featured an extended instrumental cover of "Back Stabbers". "Wish I Didn't Miss You" by Angie Stone features an interpolated composition of the song as well as samples. R&B group TLC sampled the song on the track, "Case of the Fake People" from their 1994 album CrazySexyCool. "Backstabbers" by Project Pat featuring Crucial Conflict have redone the instrumental and the chorus. B.o. B aka Bobby Ray sampled "Back Stabbers" for his own song of the same name from his mixtape Who the F#*k is B.o. B?. In 1987, jazz fusion/contemporary jazz group The Rippingtons covered the song on their 1987 album "Kilimanjaro."Rock group Barkmarket covered "Back Stabbers" on their 1991 album Vegas Throat, employing spoken-word vocals and samples from the original O'Jays cut. In 2000, the song was featured on The PJs episode "Weave's Have a Dream". In 2008, Russell Watson covered the song on his album'People Get Ready'. In 2009, the song was used in Episode 4 entitled "Soul" of the television show Cold Case.
In 2011, British soul and R&B singer-songwriter Seal included the song in his second cover album Soul 2. In 2014, the song was featured on the Simpsons episode "Pay Pal". Lyrics of this song at MetroLyrics Song review on AllMusic
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
HD Radio is a trademarked term for Xperi's in-band on-channel digital radio technology used by AM and FM radio stations to transmit audio and data by using a digital signal embedded "on-frequency" above and below a station's standard analog signal, providing the means to listen to the same program in either HD or as a standard broadcast. The HD format provides the means for a single radio station to broadcast one or more different programs in addition to the program being transmitted on the radio station's analog channel, it was developed by iBiquity. In September 2015 iBiquity was acquired by DTS bringing the HD Radio technology under the same banner as DTS' eponymous theater surround sound systems.. It was acquired by Xperi in 2016, it was selected by the U. S. Federal Communications Commission in 2002 as a digital audio broadcasting method for the United States, is the only digital system approved by the FCC for digital AM/FM broadcasts in the United States, it is known as NRSC-5, with the latest version being NRSC-5-D.
Other digital radio systems include FMeXtra, Digital Audio Broadcasting, Digital Radio Mondiale, Compatible AM-Digital. While HD Radio does allow for an all-digital mode, this system is used by some AM and FM radio stations to simulcast both digital and analog audio within the same channel as well as to add new FM channels and text information. Although HD Radio broadcasting's content is free-to-air, listeners must purchase new receivers in order to receive the digital portion of the signal. By May 2018, HD Radio technology was claimed to be used by more than 3500 individual services in the United States; this compares with more than 2200 services operating with the DAB system. HD Radio increases the bandwidth required in the FM band to 400 kHz for the analog/digital hybrid version; this makes adoption outside the United States problematic. In the United States the FM broadcast band channels have a spacing of 200 kHz, as opposed to the 100 kHz, normal elsewhere; the 200 kHz spacing means that in practice, stations having concurrent or adjacent coverage areas will not be spaced at less than 400 kHz in order to respect protection ratios which would not be met with 200 kHz spacing.
This leaves space for the digital sidebands. Outside the US, spacing can be 300 kHz; the FCC has not indicated any intent to force off analog radio broadcasts as it has with analog television broadcasts, as it would not result in the recovery of any radio spectrum rights which could be sold. Thus, there is no deadline. In addition, there are many more analog AM/FM radio receivers than there were analog televisions, many of these are car stereos or portable units that cannot be upgraded. Digital information is transmitted using OFDM with an audio compression algorithm called HDC.. HD Radio equipped stations pay a one-time licensing fee for converting their primary audio channel to iBiquity's HD Radio technology, 3% of incremental net revenues for any additional digital subchannels; the cost of converting a radio station can run between $100,000 and $200,000. Receiver manufacturers pay a royalty. If the primary digital signal is lost the HD Radio receiver will revert to the analog signal, thereby providing seamless operation between the newer and older transmission methods.
The extra HD-2 and HD-3 streams are not simulcast on analog, causing the sound to drop-out or "skip" when digital reception degrades. Alternatively the HD Radio signal can revert to a more-robust 20 kilobit per second stream, though the sound is reduced to AM-like quality. Datacasting is possible, with metadata providing song titles or artist information. IBiquity Digital claims that the system approaches CD quality audio and offers reduction of both interference and static. Sending pure digital data through the 20 kilohertz AM channel is equivalent to sending data through two 33 kbit/s analog telephone lines, thus limiting the maximum throughput possible. By using spectral band replication the HDC+SBR codec is able to simulate the recreation of sounds up to 15,000 Hz, thus achieving moderate quality on the bandwidth-tight AM band; the HD Radio AM hybrid mode offers two options which can carry 40 or 60 kbit/s of data, but most AM digital stations default to the more-robust 40 kbit/s mode which features redundancy.
HD Radio provides a pure digital mode, which lacks an analog signal for fallback and instead reverts to a 20 kbit/s signal during times of poor reception. The pure digital mode transmissions will stay within the AM station's channel instead of spilling into the channels next to the station transmitting "HD radio" as the hybrid stations do; the AM version of HD Radio technology uses the 20 kHz channel, overlaps 5 kHz into the opposite sideband of the adjacent channel on both sides. When operating in pure digital mode, the AM HD Radio signal fits inside a standard 20 kHz channel or an extended 30 kHz channel, at the discretion of the station manager; as AM radio stations are spaced at 9 kHz or 10 kHz intervals, much of the digital information overlaps adjacent channels when in hybrid mode. Some nigh
Classical music is art music produced or rooted in the traditions of Western culture, including both liturgical and secular music. While a more precise term is used to refer to the period from 1750 to 1820, this article is about the broad span of time from before the 6th century AD to the present day, which includes the Classical period and various other periods; the central norms of this tradition became codified between 1550 and 1900, known as the common-practice period. The major time divisions of Western art music are as follows: the ancient music period, before 500 AD the early music period, which includes the Medieval including the ars antiqua the ars nova the ars subtilior the Renaissance eras. Baroque the galant music period the common-practice period, which includes Baroque the galant music period Classical Romantic eras the 20th and 21st centuries which includes: the modern that overlaps from the late-19th century, impressionism that overlaps from the late-19th century neoclassicism, predominantly in the inter-war period the high modern the postmodern eras the experimental contemporary European art music is distinguished from many other non-European classical and some popular musical forms by its system of staff notation, in use since about the 11th century.
Catholic monks developed the first forms of modern European musical notation in order to standardize liturgy throughout the worldwide Church. Western staff notation is used by composers to indicate to the performer the pitches, tempo and rhythms for a piece of music; this can leave less room for practices such as improvisation and ad libitum ornamentation, which are heard in non-European art music and in popular-music styles such as jazz and blues. Another difference is that whereas most popular styles adopt the song form or a derivation of this form, classical music has been noted for its development of sophisticated forms of instrumental music such as the symphony, fugue and mixed vocal and instrumental styles such as opera and mass; the term "classical music" did not appear until the early 19th century, in an attempt to distinctly canonize the period from Johann Sebastian Bach to Ludwig van Beethoven as a golden age. The earliest reference to "classical music" recorded by the Oxford English Dictionary is from about 1829.
Given the wide range of styles in European classical music, from Medieval plainchant sung by monks to Classical and Romantic symphonies for orchestra from the 1700s and 1800s to avant-garde atonal compositions for solo piano from the 1900s, it is difficult to list characteristics that can be attributed to all works of that type. However, there are characteristics that classical music contains that few or no other genres of music contain, such as the use of music notation and the performance of complex forms of solo instrumental works. Furthermore, while the symphony did not exist prior to the late 18th century, the symphony ensemble—and the works written for it—have become a defining feature of classical music; the key characteristic of European classical music that distinguishes it from popular music and folk music is that the repertoire tends to be written down in musical notation, creating a musical part or score. This score determines details of rhythm, and, where two or more musicians are involved, how the various parts are coordinated.
The written quality of the music has enabled a high level of complexity within them: fugues, for instance, achieve a remarkable marriage of boldly distinctive melodic lines weaving in counterpoint yet creating a coherent harmonic logic that would be difficult to achieve in the heat of live improvisation. The use of written notation preserves a record of the works and enables Classical musicians to perform music from many centuries ago. Musical notation enables 2000s-era performers to sing a choral work from the 1300s Renaissance era or a 1700s Baroque concerto with many of the features of the music being reproduced; that said, the score does allow the interpreter to make choices on. For example, if the tempo is written with an Italian instruction, it is not known how fast the piece should be played; as well, in the Baroque era, many works that were designed for basso continuo accompaniment do not specify which instruments should play the accompaniment or how the chordal instrument should play the chords, which are not notated in the part.
The performer and the conductor have a range of options for musical expression and interpretation of a scored piece, including the phrasing of melodies, the time taken during fermatas or pauses, the use of effects such as vibrato or glissando. Although Classical music in the 2000s has lost most of its tradition for musical improvisation, from the Baroque era to the Romantic era, there are examples of performers who could improvise in the style of their era. In the Baroque era, organ performers would improvise preludes, keyboard performers playing harpsichord would improvise chords from the figured bass symbols beneath the bass notes of the basso continuo part and b
Philadelphia, sometimes known colloquially as Philly, is the largest city in the U. S. state and Commonwealth of Pennsylvania, the sixth-most populous U. S. city, with a 2017 census-estimated population of 1,580,863. Since 1854, the city has been coterminous with Philadelphia County, the most populous county in Pennsylvania and the urban core of the eighth-largest U. S. metropolitan statistical area, with over 6 million residents as of 2017. Philadelphia is the economic and cultural anchor of the greater Delaware Valley, located along the lower Delaware and Schuylkill Rivers, within the Northeast megalopolis; the Delaware Valley's population of 7.2 million ranks it as the eighth-largest combined statistical area in the United States. William Penn, an English Quaker, founded the city in 1682 to serve as capital of the Pennsylvania Colony. Philadelphia played an instrumental role in the American Revolution as a meeting place for the Founding Fathers of the United States, who signed the Declaration of Independence in 1776 at the Second Continental Congress, the Constitution at the Philadelphia Convention of 1787.
Several other key events occurred in Philadelphia during the Revolutionary War including the First Continental Congress, the preservation of the Liberty Bell, the Battle of Germantown, the Siege of Fort Mifflin. Philadelphia was one of the nation's capitals during the revolution, served as temporary U. S. capital while Washington, D. C. was under construction. In the 19th century, Philadelphia became a railroad hub; the city grew from an influx of European immigrants, most of whom came from Ireland and Germany—the three largest reported ancestry groups in the city as of 2015. In the early 20th century, Philadelphia became a prime destination for African Americans during the Great Migration after the Civil War, as well as Puerto Ricans; the city's population doubled from one million to two million people between 1890 and 1950. The Philadelphia area's many universities and colleges make it a top study destination, as the city has evolved into an educational and economic hub. According to the Bureau of Economic Analysis, the Philadelphia area had a gross domestic product of US$445 billion in 2017, the eighth-largest metropolitan economy in the United States.
Philadelphia is the center of economic activity in Pennsylvania and is home to five Fortune 1000 companies. The Philadelphia skyline is expanding, with a market of 81,900 commercial properties in 2016, including several nationally prominent skyscrapers. Philadelphia has more outdoor murals than any other American city. Fairmount Park, when combined with the adjacent Wissahickon Valley Park in the same watershed, is one of the largest contiguous urban park areas in the United States; the city is known for its arts, culture and colonial history, attracting 42 million domestic tourists in 2016 who spent US$6.8 billion, generating an estimated $11 billion in total economic impact in the city and surrounding four counties of Pennsylvania. Philadelphia has emerged as a biotechnology hub. Philadelphia is the birthplace of the United States Marine Corps, is the home of many U. S. firsts, including the first library, medical school, national capital, stock exchange and business school. Philadelphia contains 67 National Historic Landmarks and the World Heritage Site of Independence Hall.
The city became a member of the Organization of World Heritage Cities in 2015, as the first World Heritage City in the United States. Although Philadelphia is undergoing gentrification, the city maintains mitigation strategies to minimize displacement of homeowners in gentrifying neighborhoods. Before Europeans arrived, the Philadelphia area was home to the Lenape Indians in the village of Shackamaxon; the Lenape are a Native American tribe and First Nations band government. They are called Delaware Indians, their historical territory was along the Delaware River watershed, western Long Island, the Lower Hudson Valley. Most Lenape were pushed out of their Delaware homeland during the 18th century by expanding European colonies, exacerbated by losses from intertribal conflicts. Lenape communities were weakened by newly introduced diseases smallpox, violent conflict with Europeans. Iroquois people fought the Lenape. Surviving Lenape moved west into the upper Ohio River basin; the American Revolutionary War and United States' independence pushed them further west.
In the 1860s, the United States government sent most Lenape remaining in the eastern United States to the Indian Territory under the Indian removal policy. In the 21st century, most Lenape reside in Oklahoma, with some communities living in Wisconsin, in their traditional homelands. Europeans came to the Delaware Valley in the early 17th century, with the first settlements founded by the Dutch, who in 1623 built Fort Nassau on the Delaware River opposite the Schuylkill River in what is now Brooklawn, New Jersey; the Dutch considered the entire Delaware River valley to be part of their New Netherland colony. In 1638, Swedish settlers led by renegade Dutch established the colony of New Sweden at Fort Christina and spread out in the valley. In 1644, New Sweden supported the Susquehannocks in their military defeat of the English colony of Maryland. In 1648, the Dutch built Fort Beversreede on the west bank of the Delaware, south of the Schuylkill near the present-day Eastwick neighborhood, to reassert their dominion over the area.
The Swedes responded by building Fort Nya Korsholm, or New Korsholm, named after a town in Finland with a Swedish majority. In 1655, a
A webcast is a media presentation distributed over the Internet using streaming media technology to distribute a single content source to many simultaneous listeners/viewers. A webcast may either be distributed live or on demand. Webcasting is "broadcasting" over the Internet; the largest "webcasters" include existing radio and TV stations, who "simulcast" their output through online TV or online radio streaming, as well as a multitude of Internet only "stations". Webcasting consists of providing non-interactive linear streams or events. Rights and licensing bodies offer specific "webcasting licenses" to those wishing to carry out Internet broadcasting using copyrighted material. Webcasting is used extensively in the commercial sector for investor relations presentations, in e-learning, for related communications activities. However, webcasting does not bear much, if any, relationship to web conferencing, designed for many-to-many interaction; the ability to webcast using cheap/accessible technology has allowed independent media to flourish.
There are many notable independent shows that broadcast online. Produced by average citizens in their homes they cover many interests and topics. Webcasts relating to computers and news are popular and many new shows are added regularly. Webcasting differs from podcasting in that webcasting refers to live streaming while podcasting refers to media files placed on the Internet. Webcasting is the distribution of media files through the internet; the earliest graphically-oriented web broadcasts were not streaming video, but were in fact still frames which were photographed with a web camera every few minutes while they were being broadcast live over the Internet. One of the earliest instances of sequential live image broadcasting was in 1991 when a camera was set up next to the Trojan Room in the computer laboratory of the University of Cambridge, it provided a live picture every few minutes of the office coffee pot to all desktop computers on that office's network. A couple of years its broadcasts went to the Internet, became known as the Trojan Room Coffee Pot webcam, gained international notoriety as a feature of the fledgling World Wide Web.
In 1996 an American college student and conceptual artist, Jenny Ringley, set up a web camera similar to the Trojan Room Coffee Pot's webcam in her dorm room. That webcam photographed her every few minutes while it broadcast those images live over the Internet upon a site called JenniCam. Ringley wanted to portray all aspects of her lifestyle and the camera captured her doing everything – brushing her teeth, doing her laundry, having sex with her boyfriend, her website generated millions of hits upon the Internet, became a pay site in 1998, spawned hundreds of female imitators who would use streaming video to create a new billion dollar industry called camming, brand themselves as camgirls or webcam models. One of the earliest webcast equivalent of an online concert and one of the earliest examples of webcasting itself was by Apple Computer's Webcasting Group in partnership with the entrepreneurs Michael Dorf and Andrew Rasiej. Together with David B. Pakman from Apple, they launched the Macintosh New York Music Festival from July 17–22, 1995.
This event audio webcast concerts from more than 15 clubs in New York City. Apple webcast a concert by Metallica on June 10, 1996 live from Slim's in San Francisco. In 1995, Benford E. Standley produced one of the first audio/video webcasts in history. On October 31, 1996, UK rock band Caduseus broadcast their one-hour concert from 11 pm to 12 midnight at Celtica in Machynlleth, Wales, UK – the first live streamed audio and simultaneous live streamed video multicast – around the globe to more than twenty direct "mirrors" in more than twenty countries. In September 1997, Nebraska Public Television started webcasting Big Red Wrap Up from Lincoln, Nebraska which combined highlights from every Cornhusker football game, coverage of the coaches' weekly press conferences, analysis with Nebraska sportswriters, appearances by special guests and questions and answers with viewers. On August 13, 1998, it is believed the first webcast wedding took place, between Alan K'necht and Carrie Silverman in Toronto Canada.
On October 22, 1998, the first Billy Graham Crusade was broadcast live to a worldwide audience from the Raymond James Stadium in Tampa Florida courtesy of Dale Ficken and the WebcastCenter in Pennsylvania. The live signal was broadcast via satellite to PA encoded and streamed via the BGEA website; the first teleconferenced/webcast wedding to date is believed to have occurred on December 31, 1998. Dale Ficken and Lorrie Scarangella wed on this date as they stood in a church in Pennsylvania, were married by Jerry Falwell while he sat in his office in Lynchburg, Virginia. All major broadcasters now have a webcast of their output, from the BBC to CNN to Al Jazeera to UNTV in television to Radio China, Vatican Radio, United Nations Radio and the World Service in radio. On November 4, 1994, Stef van der Ziel distributed the first live video images over the web from the Simplon venue in Groningen. On November 7, 1994, WXYC, the college radio station of the University of North Carolina at Chapel Hill became the first radio station in the world to broadcast its signal over the internet.
Translated versions including Subtitling are now possible using SMIL Synchronized Multimedia Integration Language. A wedcast of a wedding. Allows family and friends of the couple to watch the wedding in real time on the Internet, it is sometimes used for weddings in exotic locations, such as Cancun and the Riviera Maya, Hawaii or the Caribbean, for which it is expensive or difficul