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
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
In broadcasting and radio communications, a call sign is a unique designation for a transmitter station. In the United States of America, they are used for all FCC-licensed transmitters. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or cryptographically encoded to disguise a station's identity; the use of call signs as unique identifiers dates to the landline railroad telegraph system. Because there was only one telegraph line linking all railroad stations, there needed to be a way to address each one when sending a telegram. In order to save time, two-letter identifiers were adopted for this purpose; this pattern continued in radiotelegraph operation. These were not globally unique, so a one-letter company identifier was added. By 1912, the need to identify stations operated by multiple companies in multiple nations required an international standard. Merchant and naval vessels are assigned call signs by their national licensing authorities.
In the case of states such as Liberia or Panama, which are flags of convenience for ship registration, call signs for larger vessels consist of the national prefix plus three letters. United States merchant vessels are given call signs beginning with the letters "W" or "K" while US naval ships are assigned call signs beginning with "N". Both ships and broadcast stations were assigned call signs in this series consisting of three or four letters. Ships equipped with Morse code radiotelegraphy, or life boat radio sets, Aviation ground stations, broadcast stations were given four letter call signs. Maritime coast stations on high frequency were assigned three letter call signs; as demand for both marine radio and broadcast call signs grew American-flagged vessels with radiotelephony only were given longer call signs with mixed letters and numbers. Leisure craft with VHF radios may not be assigned call signs, in which case the name of the vessel is used instead. Ships in the US still wishing to have a radio license are under FCC class SA: "Ship recreational or voluntarily equipped."
Those calls follow the land mobile format of the initial letter K or W followed by 1 or 2 letters followed by 3 or 4 numbers. U. S. Coast Guard small boats have a number, shown on both bows in which the first two digits indicate the nominal length of the boat in feet. For example, Coast Guard 47021 refers to the 21st in the series of 47-foot motor lifeboats; the call sign might be abbreviated to the final two or three numbers during operations, for example: Coast Guard zero two one. Aviation mobile stations equipped with radiotelegraphy were assigned five letter call signs.. Land Stations in Aviation were assigned four letter call signs; these call signs were phased out in the 1960s when flight radio officers were no longer required on international flights. USSR kept FRO's for the Moscow-Havana run until around 2000. All signs in aviation are derived from several different policies, depending upon the type of flight operation and whether or not the caller is in an aircraft or at a ground facility.
In most countries, unscheduled general aviation flights identify themselves using the call sign corresponding to the aircraft's registration number. In this case, the call sign is spoken using the International Civil Aviation Organization phonetic alphabet. Aircraft registration numbers internationally follow the pattern of a country prefix, followed by a unique identifier made up of letters and numbers. For example, an aircraft registered as N978CP conducting a general aviation flight would use the call sign November-niner-seven-eight-Charlie-Papa. However, in the United States a pilot of an aircraft would omit saying November, instead use the name of the aircraft manufacturer or the specific model. At times, general aviation pilots might omit additional preceding numbers and use only the last three numbers and letters; this is true at uncontrolled fields when reporting traffic pattern positions or at towered airports after establishing two-way communication with the tower controller. For example, Skyhawk eight-Charlie-Papa, left base.
In most countries, the aircraft call sign or "tail number"/"tail letters" are linked to the international radio call sign allocation table and follow a convention that aircraft radio stations receive call signs consisting of five letters. For example, all British civil aircraft have a five-letter call sign beginning with the letter G. Canadian aircraft have a call sign beginning with C–F or C–G, such as C–FABC. Wing In Ground-effect vehicles in Canada are eligible to receive C–Hxxx call signs, ultralight aircraft receive C-Ixxx call signs. In days gone by American aircraft used five letter call signs, such as KH–ABC, but they were replaced prior to World War II by the current American system of civilian aircraft call signs. Radio call signs used for communication in manned spaceflight is not formalized or regulated to the same degree as for aircraft; the three nations curren
Broken Arrow, Oklahoma
Broken Arrow is a city located in the northeastern part of the U. S. state of Oklahoma in Tulsa County but with a section of the city in western Wagoner County. It is the largest suburb of Tulsa. According to the 2010 census, Broken Arrow has a population of 98,850 residents and is the fourth-largest city in the state. However, a July 2017, estimate reports that the population of the city is just under 112,000, making it the 280th-largest city in the United States; the city is part of the Tulsa Metropolitan Area. The Missouri–Kansas–Texas Railroad sold lots for the town site in 1902 and company secretary William S. Fears named it Broken Arrow; the city was named for a Creek community settled by Creek Indians, forced to relocate from Alabama to Oklahoma along the Trail of Tears. Although Broken Arrow was an agricultural community, its current economy is diverse; the city has the third-largest concentration of manufacturers in the state. The city's name comes from an old Creek community in Alabama.
Members of that community were expelled from Alabama by the United States government, along the Trail of Tears in the 1830s. The Creek founded a new community in the Indian Territory, named it after their old settlement in Alabama; the town's Creek name was Rekackv. The new Creek settlement was located several miles south of present-day downtown Broken Arrow. In 1902 the Missouri–Kansas–Texas Railroad planned a railroad through the area and was granted town site privileges along the route, they sold three of the as-yet-unnamed sites to the Arkansas Valley Town Site Company. William S. Fears, secretary of that company, was allowed to name one of the locations, he selected a site about 18 miles southeast of Tulsa and about five miles north of the thlee-Kawtch-kuh settlement and named the new town site Broken Arrow, after the Indian settlement. The MKT railroad, completed in 1903, ran through the middle of the city, it still exists today and is now owned by Union Pacific which uses it for freight.
For the first decades of Broken Arrow's history, the town's economy was based on agriculture. The coal industry played an important role, with several strip coal mines located near the city in the early 20th century; the city's newspaper, the Broken Arrow Ledger, started within a couple of years of the city's founding. Broken Arrow's first school was built in 1904; the city did not grow much during the first half of the 1900s. During this time Broken Arrow's main commercial center was along Main Street. Most of the city's churches were located on or near Main Street as well. A 1907 government census listed Broken Arrow's population at 1383; the Haskell State School of Agriculture opened in the Broken Arrow, Oklahoma Opera House on November 15, 1909. The school closed in 1917 for lack of funding, the building was used as Broken Arrow High School; the building was razed in 1987. Only a marker, shown here, remains at 808 East College Street in Broken Arrow; the front of cornerstone reads, "Haskell State School / Of Agriculture / J. H. Esslinger Supt. / W. A. Etherton Archt.
/ Bucy & Walker Contr." The side of cornerstone reads "Laid by the Masonic Fraternity / May 25, A. D. 1910, A. L. 5810. / George Huddell G. M. / Erected by The State Board of Agriculture / J. P. Conners Pres. / B. C. Pittuck Dean.". The school is commemorated on the National Register of Historic Places. In the 1960s, Broken Arrow began to grow from a small town into a suburban city; the Broken Arrow Expressway was constructed in the mid-1960s and connected the city with downtown Tulsa, fueling growth in Broken Arrow. The population swelled from a little above 11,000 in 1970 to more than 50,000 in 1990, more than 74,000 by the year 2000. During this time, the city was more of a bedroom community. In recent years, city leaders have pushed for more economic development to help keep more Broken Arrowans working and relaxing in town rather than going to other cities. Broken Arrow is located in the northeastern corner of Oklahoma; the city is part of the state's Green Country region known for its green vegetation and lakes.
Green Country is the most topographically diverse portion of the state with seven of Oklahoma's 11 eco-regions. According to the United States Census Bureau, the city has a total area of 45.6 square miles, of which 45.0 sq mi is land and 0.6 sq mi is water. Broken Arrow has the typical eastern and central Oklahoma humid subtropical climate with uncomfortably hot summers and variable winters that can range from warm to cold depending on whether the air mass comes from warmed air over the Rocky Mountains or cold polar anticyclones from Canada. According to the 2010 census, there were 98,850 people, 36,141 households, 27,614 families residing in the city; the population density was 2,200 people per square mile. There were 38,013 housing units at an average density of 602.0 per square mile. The racial makeup of the city was 79.3% White, 4.3% African American, 5.2% Native American, 3.6% Asian, 0.05% Pacific Islander, 2.2% from other races, 5.4% from two or more races. Hispanic or Latino were 6.5%.
There were 36,141 households, out of which 36.8% had children under the age of 18 living with them, 76.4% were married couples living together, 10.3% had a female householder with no husband present, 23.6% were non-families. Of all households, 19.2% were made up of individuals and 6.3% h
Oklahoma is a state in the South Central region of the United States, bordered by Kansas on the north, Missouri on the northeast, Arkansas on the east, Texas on the south, New Mexico on the west, Colorado on the northwest. It is the 28th-most populous of the fifty United States; the state's name is derived from the Choctaw words okla and humma, meaning "red people". It is known informally by its nickname, "The Sooner State", in reference to the non-Native settlers who staked their claims on land before the official opening date of lands in the western Oklahoma Territory or before the Indian Appropriations Act of 1889, which increased European-American settlement in the eastern Indian Territory. Oklahoma Territory and Indian Territory were merged into the State of Oklahoma when it became the 46th state to enter the union on November 16, 1907, its residents are known as Oklahomans, its capital and largest city is Oklahoma City. A major producer of natural gas and agricultural products, Oklahoma relies on an economic base of aviation, telecommunications, biotechnology.
Both Oklahoma City and Tulsa serve as Oklahoma's primary economic anchors, with nearly two thirds of Oklahomans living within their metropolitan statistical areas. With ancient mountain ranges, prairie and eastern forests, most of Oklahoma lies in the Great Plains, Cross Timbers, the U. S. Interior Highlands, a region prone to severe weather. More than 25 Native American languages are spoken in Oklahoma, ranking third behind Alaska and California. Oklahoma is on a confluence of three major American cultural regions and served as a route for cattle drives, a destination for Southern settlers, a government-sanctioned territory for Native Americans; the name Oklahoma comes from the Choctaw phrase okla humma meaning red people. Choctaw Nation Chief Allen Wright suggested the name in 1866 during treaty negotiations with the federal government on the use of Indian Territory, in which he envisioned an all-Indian state controlled by the United States Superintendent of Indian Affairs. Equivalent to the English word Indian, okla humma was a phrase in the Choctaw language that described Native American people as a whole.
Oklahoma became the de facto name for Oklahoma Territory, it was approved in 1890, two years after the area was opened to white settlers. The name of the state is Pawnee: Uukuhuúwa, Cayuga: Gahnawiyoˀgeh. In the Chickasaw language, the state is known as Oklahomma', in Arapaho as bo'oobe'. Oklahoma is the 20th-largest state in the United States, covering an area of 69,899 square miles, with 68,595 square miles of land and 1,304 square miles of water, it lies in the Great Plains near the geographical center of the 48 contiguous states. It is bounded on the east by Arkansas and Missouri, on the north by Kansas, on the northwest by Colorado, on the far west by New Mexico, on the south and near-west by Texas. Much of its border with Texas lies along a failed continental rift; the geologic figure defines the placement of the Red River. The Oklahoma panhandle's Western edge is out of alignment with its Texas border; the Oklahoma/New Mexico border is 2.1 miles to 2.2 miles east of the Texas line. The border between Texas and New Mexico was set first as a result of a survey by Spain in 1819.
It was set along the 103rd meridian. In the 1890s, when Oklahoma was formally surveyed using more accurate surveying equipment and techniques, it was discovered the Texas line was not set along the 103rd meridian. Surveying techniques were not as accurate in 1819, the actual 103rd meridian was 2.2 miles to the east. It was much easier to leave the mistake than for Texas to cede land to New Mexico to correct the surveying error; the placement of the Oklahoma/New Mexico border represents the true 103rd meridian. Cimarron County in Oklahoma's panhandle is the only county in the United States that touches four other states: New Mexico, Texas and Kansas. Oklahoma is between the Great Plains and the Ozark Plateau in the Gulf of Mexico watershed sloping from the high plains of its western boundary to the low wetlands of its southeastern boundary, its highest and lowest points follow this trend, with its highest peak, Black Mesa, at 4,973 feet above sea level, situated near its far northwest corner in the Oklahoma Panhandle.
The state's lowest point is on the Little River near its far southeastern boundary near the town of Idabel, which dips to 289 feet above sea level. Among the most geographically diverse states, Oklahoma is one of four to harbor more than 10 distinct ecological regions, with 11 in its borders—more per square mile than in any other state, its western and eastern halves, are marked by extreme differences in geographical diversity: Eastern Oklahoma touches eight ecological regions and its western half contains three. Although having fewer ecological regions Western Oklahoma contains many relic species. Oklahoma has four primary mountain ranges: the Ouachita Mountains, the Arbuckle Mountains, the Wichita Mountains, the Ozark Mountains. Contained within the U. S. Interior Highlands region, the Ozark and Ouachita Mountains are the only major mountainous region between the Rocky Mountains and the Appalachians. A portion of the Flint Hills stretches into north-central Oklahoma, near the state's eastern border, The Oklahoma Tourism & Recreation Department regards Cavanal Hill as the world's tallest hill.
The semi-arid high
Air1 is an American Christian radio network. Owned by the Educational Media Foundation, it broadcasts contemporary worship music, is a sister to the EMF's K-Love network. In 1986, KLRD began broadcasting Christian Hit/Rock music from Yucaipa and went by the on-air moniker K-LORD. In 1994, KXRD was started as a sister station to KLRD. In 1995, K-LORD changed its name to "Air1" and began broadcasting via satellite from St. Helens, Oregon. In 1999, Air1 joined with EMF Broadcasting, in 2002, it moved its headquarters to Rocklin, California. Air1 makes use of broadcast translators to spread the signal across much of the country; as of December 2017, the network lists 123 full powered radio stations and 125 translators of various power levels reaching 43 states. Air1 began as a Christian rock-formatted radio network with the tagline "The Positive Alternative". Over time, the network evolved into a broad Christian CHR presentation, with the slogan "Positive Hits". In October 2018, Air1 named Mandy Young, the network's assistant PD and morning co-host, as its new head program director.
On January 1, 2019, Air1 re-launched with a focus on contemporary worship music—with the majority of its music now focusing on songs from church worship bands such as Elevation Worship, Hillsong Worship, Vertical Worship. As of January 1, 2019, the on-air staff of Air1 includes morning drive hosts Dan and Michelle Arthur, program director Mandy Young in middays, “Shaef & Lee” in afternoon drive, Ashton in evenings. Eric Calhoun and Heather Shelley hosted Air1's morning show from April 2015 to November 2018. Sean Copeland was part of the Sean and Mandy show, discontinued on September 29, 2011. Copeland moved to the morning show on Indianapolis adult contemporary station WYXB. Coppelia Acevedo occupied the midday time slot, moved to Houston station KSBJ. Brant Hansen filled the afternoon time slot from 2011 to 2014, he resigned to work with nonprofit Cure International and launch The Brant Hansen Show, a podcast, syndicated on many Christian radio stations. Eric Allen co-hosted the "Eric and Mandy Show" in the mornings until February 2015.
As of 2015, Eric is working for Cure International as their Radio Marketing Manager. Brenda Price hosted a mid-day time slot until May 5, 2015, when Air1 stated Brenda was no longer a part of Air1's DJ lineup. No reason was given for her sudden departure. Rahny Taylor worked as a program director and on-air host at Air1 and K-Love from November 2013 to August 2016, he departed to host a morning show on WRNW in Milwaukee. Official website