Buttonville is a suburban planned neighbourhood from a former Police village in the city of Markham, Canada, west of the larger Unionville neighbourhood. It is a former Police village, named after its founder, John Button. About 30,000 residents live in the area, it is located along the Woodbine Avenue corridor from Highway 7 in the south to Sixteenth Avenue in the north. The Rouge River is in the northeast and Buttonville Airport and Highway 404 are in the west, with three interchanges; the residential area is located in the eastern and the northern section while the industrial area is situated to the west and south down to Highway 7. The area is home to many technology companies near the airport. There is talk about renaming the community, the John Button Community after its founder since there has been lots of confusion between Unionville and Buttonville, popularly considered to be part of Unionville; the area was first settled by William Berczy. The police village in Unionville was named after John Button who bought property here in 1808.
By 1860, John Button's descendants owned a number of lots in. By 1878 the village had a post office, a grist mill, a wagon maker, a school, a Lutheran church and a Methodist church. Unionville housing developments did not began until the 1960s near Cachet Woods at Woodbine Ave. and Major Mackenzie Drive, the industrial area began to appear further south. In the 1980s housing developments came to the western part of Markham along with the industries which flowed with technological and financial companies including Allstate. Buttonville was first accessed. Between 1994 and 1996, more houses continued northeast of Buttonville and a few years north of the airport and more housing continued until 2004. Population: 1990: about 10,000 2002: about 30,000 Farmlands surrounded Buttonville and forests were around Buttonville to its south. Between 1980 and 2000, the farmlands were developed. Toronto/Buttonville Municipal Airport is located at 16th Avenue and Highway 404Public transit in Buttonville is served by: York Region Transit/Viva routes Viva Purple, 1 Highway 7, 85 Rutherford-16th, 24 Woodbine operates regular bus service.
The neighbourhood is served by one major highways and several arterial roads: Highway 404 runs north-south on the west side of and connected to east-south streets Highway 7 runs east-west on the south side. Sixteenth Avenue runs east-west on the north side. Woodbine Avenue runs north-south through its centre; the historic settlement is located along it south of Sixteenth Avenue. Richmond Hill, west Unionville, east Milliken, south Stouffville, north
London is a city in Southwestern Ontario, Canada along the Quebec City–Windsor Corridor. The city had a population of 383,822 according to the 2016 Canadian census. London is at the confluence of the Thames River 200 km from both Toronto and Detroit; the city of London is a separated municipality, politically separate from Middlesex County, though it remains the county seat. London and the Thames were named in 1793 by John Graves Simcoe, who proposed the site for the capital city of Upper Canada; the first European settlement was between 1804 by Peter Hagerman. The village was founded in 1826 and incorporated in 1855. Since London has grown to be the largest Southwestern Ontario municipality and Canada's 11th largest metropolitan area, having annexed many of the smaller communities that surrounded it. London is a regional centre of healthcare and education, being home to the University of Western Ontario, Fanshawe College, several hospitals; the city hosts a number of musical and artistic exhibits and festivals, which contribute to its tourism industry, but its economic activity is centred on education, medical research and information technology.
London's university and hospitals are among its top ten employers. London lies at the junction of Highway 401 and 402, connecting it to Toronto and Sarnia, it has an international airport and bus station. Prior to European contact in the 18th century, the present site of London was occupied by several Neutral and Ojibwe villages. Archaeological investigations in the region show aboriginal people have resided in the area for at least the past 10,000 years; the current location of London was selected as the site of the future capital of Upper Canada in 1793 by Lieutenant-Governor John Graves Simcoe, who named the village, founded in 1826. It did not become the capital Simcoe envisioned. Rather, it was an administrative seat for the area west of York. Locally, it was part of the Talbot Settlement, named for Colonel Thomas Talbot, the chief coloniser of the area, who oversaw the land surveying and built the first government buildings for the administration of the Western Ontario peninsular region.
Together with the rest of Southwestern Ontario, the village benefited from Talbot's provisions, not only for building and maintaining roads but for assignment of access priorities to main routes to productive land. At the time and clergy reserves were receiving preference in the rest of Ontario. In 1814, there was a skirmish during the War of 1812 in what is now southwest London at Reservoir Hill Hungerford Hill. In 1832, the new settlement suffered an outbreak of cholera. London proved a centre of strong Tory support during the Upper Canada Rebellion of 1837, notwithstanding a brief rebellion led by Charles Duncombe; the British government located its Ontario peninsular garrison there in 1838, increasing its population with soldiers and their dependents, the business support populations they required. London was incorporated as a town in 1840. On 13 April 1845, fire destroyed much of London, at the time constructed of wooden buildings. One of the first casualties was the town's only fire engine.
The fire burned nearly 30 acres of land, destroying 150 buildings, before burning itself out the same day. One-fifth of London was destroyed and this was the province's first million dollar fire. Sir John Carling, Tory MP for London, gave three events to explain the development of London in a 1901 speech, they were: the location of the court and administration in London in 1826. The population in 1846 was 3,500. Brick buildings included a jail and court house, large barracks. London had a fire company, a theatre, a large Gothic church, nine other churches or chapels, two market buildings. In 1845, a fire destroyed 150 buildings but most had been rebuilt by 1846. Connection with other communities was by road using stages that ran daily. A weekly newspaper was published and mail was received daily by the post office. On 1 January 1855, London was incorporated as a "city". In the 1860s, a sulphur spring was discovered at the forks of the Thames River while industrialists were drilling for oil; the springs became a popular destination for wealthy Ontarians, until the turn of the 20th century when a textile factory was built at the site, replacing the spa.
Records from 1869 indicate a population of about 18,000 served by three newspapers, churches of all major denominations and offices of all the major banks. Industry included several tanneries, oil refineries and foundries, four flour mills, the Labatt Brewing Company and the Carling brewery in addition to other manufacturing. Both the Great Western and Grand Trunk railways had stops here. Several insurance companies had offices in the city; the Crystal Palace Barracks, built in 1861, an octagonal brick building with eight doors and forty-eight windows, was used for events such the Provincial Agricultural Fair of Canada West held in London that year. It was visited by Prince Arthur, Duke of Connaught and Strathearn, Governor-General John Young, 1st Baron Lisgar and Prime Minister Sir John A. Macdonald.. Long before the Royal Military College of Canada was established in 1876, there were proposals for military colleges in Canada. Staffed by British Regulars, adult male students underwent a 3 month long military courses from 1865 at the School of Military Instruction in London.
Established by Militia General Order in 1865, the school enabled Officers of Militia or Candidates for Commission or promotion in the M
A non-directional beacon is a radio transmitter at a known location, used as an aviation or marine navigational aid. As the name implies, the signal transmitted does not include inherent directional information, in contrast to other navigational aids such as low frequency radio range, VHF omnidirectional range and TACAN. NDB signals follow the curvature of the Earth, so they can be received at much greater distances at lower altitudes, a major advantage over VOR. However, NDB signals are affected more by atmospheric conditions, mountainous terrain, coastal refraction and electrical storms at long range. NDBs used for aviation are standardised by ICAO Annex 10 which specifies that NDBs be operated on a frequency between 190 kHz and 1750 kHz, although all NDBs in North America operate between 190 kHz and 535 kHz; each NDB is identified by two, or three-letter Morse code callsign. In Canada owned NDB identifiers consist of one letter and one number. North American NDBs are categorized by power output, with low power rated at less than 50 watts, medium from 50 W to 2,000 W and high being over 2,000 W.
There are four types of non-directional beacons in the aeronautical navigation service: En route NDBs, used to mark airways Approach NDBs Localizer beacons Locator beaconsThe last two types are used in conjunction with an Instrument Landing System. NDB navigation consists of two parts — the automatic direction finder equipment on the aircraft that detects an NDB's signal, the NDB transmitter; the ADF can locate transmitters in the standard AM medium wave broadcast band. ADF equipment determines the direction or bearing to the NDB station relative to the aircraft by using a combination of directional and non-directional antennae to sense the direction in which the combined signal is strongest; this bearing may be displayed on a relative bearing indicator. This display looks like a compass card with a needle superimposed, except that the card is fixed with the 0 degree position corresponding to the centreline of the aircraft. In order to track toward an NDB, the aircraft is flown so that the needle points to the 0 degree position.
The aircraft will fly directly to the NDB. The aircraft will track directly away from the NDB if the needle is maintained on the 180 degree mark. With a crosswind, the needle must be maintained to the left or right of the 0 or 180 position by an amount corresponding to the drift due to the crosswind.. The formula to determine the compass heading to an NDB station is to take the relative bearing between the aircraft and the station, add the magnetic heading of the aircraft; this gives the magnetic bearing that must be flown: mod 360 = MB. When tracking to or from an NDB, it is usual that the aircraft track on a specific bearing. To do this it is necessary to correlate the RBI reading with the compass heading. Having determined the drift, the aircraft must be flown so that the compass heading is the required bearing adjusted for drift at the same time as the RBI reading is 0 or 180 adjusted for drift. An NDB may be used to locate a position along the aircraft's current track; when the needle reaches an RBI reading corresponding to the required bearing the aircraft is at the position.
However, using a separate RBI and compass, this requires considerable mental calculation to determine the appropriate relative bearing. To simplify this task, a compass card driven by the aircraft's magnetic compass is added to the RBI to form a "Radio Magnetic Indicator"; the ADF needle is referenced to the aircraft's magnetic heading, which reduces the necessity for mental calculation. Many RMIs used for aviation allow the device to display information from a second radio tuned to a VOR station; this display, along with the "Omni Bearing Indicator" for VOR/ILS information, was one of the primary radionavigation instruments prior to the introduction of the Horizontal Situation Indicator and subsequent digital displays used in glass cockpits. The principles of ADFs are not limited to NDB usage. A bearing is a line passing through the station that points in a specific direction, such as 270 degrees. NDB bearings provide a consistent method for defining paths aircraft can fly. In this fashion, NDBs can, like VORs, define "airways" in the sky.
Aircraft follow these pre-defined routes to complete a flight plan. Airways are standardized on charts. Colored airways are used for low to medium frequency stations like the NDB and are charted in brown on sectional charts. Green and red airways are plotted east and west, while amber and blue airways are plotted north and south. There is only one colored airway left in the continental United States, located off the coast of North Carolina and is called G13 or Green 13. Alaska is the only other state in the United States to make use of the colored airway systems. Pilots follow these routes by tracking radials across various navigation stations, turning at some. While most airways in the United States are based on VORs, NDB airways are c
A condominium shortened to condo, in the United States and in most Canadian provinces, is a type of living space similar to an apartment but independently sellable and therefore regarded as real estate. The condominium building structure is divided into several units that are each separately owned, surrounded by common areas that are jointly owned. Similar concepts in other English-speaking countries include strata title in Australia, New Zealand, the Canadian province of British Columbia. Residential condominiums are constructed as apartment buildings, but there has been an increase in the number of "detached condominiums", which look like single-family homes but in which the yards, building exteriors, streets are jointly owned and jointly maintained by a community association. Unlike apartments, which are leased by their tenants, condominium units are owned outright. Additionally, the owners of the individual units collectively own the common areas of the property, such as hallways, laundry rooms, etc. as well as common utilities and amenities, such as the HVAC system, so on.
Many shopping malls are industrial condominiums in which the individual retail and office spaces are owned by the businesses that occupy them while the common areas of the mall are collectively owned by all the business entities that own the individual spaces. The common areas and utilities are managed collectively by the owners through their association, such as a homeowner association. Scholars have traced the earliest known use of the condominium form of tenure to a document from first-century Babylon; the word condominium originated in Latin. Italy uses condominio, the modern Italian form of condominium. Both condo and condominium are used colloquially in the Canadian province of Quebec, where the official term is divided co-ownership. In France, the term is copropriété, the common areas of these properties are managed by a Syndicat de copropriété, or "co-property union". Latin American nations use the term propiedad horizontal meaning "horizontal property" but abstractly meaning that all owners of the property have equal interest.
The word condominio is used. However, in Spain, the legal term is comunidad de propietarios and the popular term is comunidad de vecinos. "Condominium" is a Latin word formed by adding the prefix con- to the word dominium. Its meaning is therefore "shared property". Condominia referred to territories over which two or more sovereign powers shared joint dominion; this technique was used to settle border disputes when multiple claimants could not agree on how to partition the disputed territory. For example, from 1818 to 1846, Oregon Country was a condominium over which both the United States and Great Britain shared joint sovereignty until the Oregon Treaty resolved the issue by splitting the territory along the 49th parallel and each country gaining sole sovereignty of one side; the difference between an "apartment" complex and condominium is purely legal. There is no way to differentiate a condominium from an apartment by looking at or visiting the building. What defines. A building developed as a condominium could be built at another location as an apartment building.
As a practical matter, builders tend to build condominiums to higher quality standards than apartment complexes because of the differences between the rental and sale markets. Technically, a condominium is a collection of individual home units and common areas along with the land upon which they sit. Individual home ownership within a condominium is construed as ownership of only the air space confining the boundaries of the home; the boundaries of that space are specified by a legal document known as a Declaration, filed on record with the local governing authority. These boundaries will include the wall surrounding a condo, allowing the homeowner to make some interior modifications without impacting the common area. Anything outside this boundary is held in an undivided ownership interest by a corporation established at the time of the condominium's creation; the corporation holds this property in trust on behalf of the homeowners as a group—it may not have ownership itself. Condominiums have conditions and restrictions, additional rules that govern how the individual unit owners are to share the space.
It is possible for a condominium to consist of single-family dwellings. There are "detached condominiums" where homeowners do not maintain the exteriors of the dwellings, etc. and "site condominiums" where the owner has more control and ownership over the exterior appearance. These structures are preferred by gated communities. A homeowners association, whose members are the unit owners, manages the condominium through a board of directors elected by the membership; this exists under various names depending on the jurisdiction, such as "unit title", "sectional title", "commonhold", "strata council", or "tenant-owner's association", "body corporate", "Owners Corporation", "condominium corporation" or "condominium association". Another variation of this concept is the "time share", although not all time shares are condominiums, not all time shares involve actual ownership of real property. C
Toronto Pearson International Airport
Lester B. Pearson International Airport, corporately branded as Toronto Pearson International Airport, is the primary international airport serving Toronto, its metropolitan area, surrounding region known as the Golden Horseshoe in the province of Ontario, Canada, it is the largest and busiest airport in Canada, the second-busiest international air passenger gateway in the Americas, the 31st-busiest airport in the world by passenger traffic, handling 49.5 million passengers in 2018. The airport is named in honour of Lester B. Pearson, Nobel Peace Prize laureate and 14th Prime Minister of Canada. Toronto Pearson is located 22.5 kilometres northwest of Downtown Toronto, with the majority of the airport situated in the adjacent city of Mississauga, a small portion of the airfield extending into Toronto's western district of Etobicoke. It features five runways and two passenger terminals along with numerous cargo and maintenance facilities on a site that covers 1,867 hectares. Pearson Airport is the primary hub for Air Canada.
It serves as a hub for WestJet, cargo airline FedEx Express and as a base of operations for Air Transat and Sunwing Airlines. Pearson is operated by the Greater Toronto Airports Authority as part of Transport Canada's National Airports System, is the largest airport in the world with facilities for United States border preclearance. An extensive network of non-stop domestic flights is operated from Toronto Pearson by several airlines to all major and many secondary cities across all provinces of Canada; as of 2019, over 75 airlines operate around 1,250 daily departures from the airport to more than 180 destinations across all six of the world's inhabited continents. In 1937, the Government of Canada agreed to support the building of two airports in the Toronto area. One site selected was on the Toronto Islands in Downtown Toronto, the present-day Billy Bishop Toronto City Airport; the other site selected was an area northwest of Toronto near the town of Malton, intended to serve as an alternate to the downtown airport but instead would become its successor.
The first scheduled passenger flight at the Malton Airport was a Trans-Canada Air Lines DC-3 that landed on August 29, 1939. During World War II, the Royal Canadian Air Force established a base at the airport as a component of the British Commonwealth Air Training Plan. RCAF Station Malton was home to several training schools and was in operation between 1940-1946. In 1958, the City of Toronto sold the Malton Airport to the Government of Canada, which subsequently changed the name of the facility to Toronto International Airport, under the management of Transport Canada; the airport was renamed Lester B. Pearson International Airport in 1984, in honour of Toronto-born Lester B. Pearson, the fourteenth Prime Minister of Canada and recipient of the 1957 Nobel Peace Prize; the Greater Toronto Airports Authority assumed management and control of the airport in 1996, has used the name Toronto Pearson International Airport for the facility since the transition. Toronto Pearson International Airport has two active public terminals, Terminal 1 and Terminal 3.
Both terminals are designed to handle all three sectors of travel, which results in terminal operations at Pearson being grouped for airlines and airline alliances, rather than for domestic and international routes. Terminal 2 was demolished and replaced with an expanded Terminal 1. A third public terminal, the Infield Concourse acts as an extension of Terminal 3 providing additional bridged gates. Measuring over 346,000 square metres, Terminal 1 is the largest airport terminal in Canada and the 12th largest in the world by floor space. Air Canada and all other Star Alliance airlines that serve Pearson are based at Terminal 1. Non-alliance airline Emirates uses the terminal. Terminal 1 was designed by a joint venture known as Airports Architects Canada made up of Skidmore, Owings & Merrill LLP, Adamson Associates Architects and Moshe Safdie and Associates, it contains 58 gates: D1, D3, D5, D7-D12, D20, D22, D24, D26, D28, D31–D45, D51, D53, D55, D57, F60–F63, F64A–F64B, F65, F66A–F66B, F/E67–F/E81, F59, F82-F83, F84-F99.
Two of the gates, E73 and E75, can accommodate the Airbus A380. Along with the standard customs and immigration facilities, Terminal 1 contains special customs "B" checkpoints along the international arrivals walkway. Passengers connecting from an international or trans-border arrival to another international departure in Terminal 1 go to one of these checkpoints for passport control and immigration checks are directed to Pier F for departure; this alleviates the need to recheck bags, pass through security screening, relieves congestion in the primary customs hall. An eight-level parking garage with 8,400 public parking spaces across from Terminal 1 is connected to the terminal by several elevated and enclosed pedestrian walkways. Terminal 1 is home to the world's fastest moving walkway. Terminal 3 is a 178,000-square-metre facility designed by B+H Architects and Scott Associates Architects Inc, it is used by all SkyTeam and Oneworld airlines that serve Pearson, along with Air Transat, Etihad Airways, Sunwing Airlines, WestJet and all other airlines that are unaffiliated with an airline alliance.
Terminal 3 has 46 gates: B1a-B1d, B2a, B2c, B3-B5
Environment and Climate Change Canada
Environment and Climate Change Canada incorporated as the Department of the Environment under the Department of the Environment Act, is the department of the Government of Canada with responsibility for coordinating environmental policies and programs as well as preserving and enhancing the natural environment and renewable resources. The powers and functions of the Minister of the Environment extend to and include matters relating to: "preserve and enhance the quality of the natural environment, including water, soil and fauna, its ministerial headquarters is located in les Terrasses de la Chaudière, Quebec. Under the Canadian Environmental Protection Act, Environment Canada became the lead federal department to ensure the cleanup of hazardous waste and oil spills for which the government is responsible, to provide technical assistance to other jurisdictions and the private sector as required; the department is responsible for international environmental issues. CEPA was the central piece of Canada's environmental legislation but was replaced when budget implementation bill entered into effect in June 2012.
Under the Constitution of Canada, responsibility for environmental management in Canada is a shared responsibility between the federal government and provincial/territorial governments. For example, provincial governments have primary authority for resource management including permitting industrial waste discharges; the federal government is responsible for the management of toxic substances in the country. Environment Canada provides stewardship of the Environmental Choice Program, which provides consumers with an eco-labelling for products manufactured within Canada or services that meet international label standards of Global Ecolabelling Network. Environment Canada continues to undergo a structural transformation to centralize authority and decision-making, to standardize policy implementation. Minister Deputy Minister Associate Deputy Minister Assistant Deputy Minister Associate Assistant Deputy Minister Director General Director Managers Supervisors Staff Environment Canada is divided into several geographic regions: National Capital Atlantic and Quebec Region Ontario West and North The department has several organizations which carry out specific tasks: Enforcement Branch Environmental Enforcement Wildlife Enforcement Environmental Protection Branch Canadian Wildlife Service Chemical Sectors Energy and Transportation Environmental Protection Operations Legislative and Regulatory Affairs Strategic Priorities Meteorological Service of Canada Weather and environmental monitoring Weather and Environmental Operations Weather and Environmental Prediction and Services Canadian Hurricane Centre Science and Technology Branch Atmospheric and Climate Science Water Science and Technology Directorate National Pollutant Release Inventory Wildlife and Landscape Science Air Quality Mobile Source Emissions Measurement and ResearchThe Canadian Environmental Assessment Agency is an arms-length agency that reports to the Minister of EnvironmentParks Canada, which manages the Canadian National Parks system, was removed from Environment Canada and became an agency reporting to the Minister of Heritage in 1998.
In 2003, responsibility for Parks Canada was returned to the Minister of the Environment. Environment Canada Enforcement Branch is responsible for ensuring compliance with several federal statues; the Governor-in-Council appoints enforcement officers and pursuant to section 217 of the Canadian Environmental Protection Act, enforcement officers have all the powers of peace officers. There are two designations of enforcement officers: Environmental Enforcement and Wildlife Enforcement; the former administers the Canadian Environmental Protection Act and pollution provisions of the Fisheries Act and corresponding regulations. The latter enforces Migratory Birds Convention Act, Canada Wildlife Act, Species at Risk Act and The Wild Animal and Plant Protection and Regulation of International and Interprovincial Trade Act. All officers wear dark green uniform with a badge. Environmental Enforcement Officers only carry baton and OC spray whereas Wildlife Enforcement Officers are equipped with firearm.
The Minister may appoint members of the Royal Canadian Mounted Police, fishery officers, parks officers, customs officers and conservation officers of provincial and territorial governments as enforcement officers and to allow them to exercise the powers and privilege of Environment Canada officers. On March 4, 2009, a bill to increase the enforcement capabilities of Environment Canada was introduced into the House of Commons; the Environmental Enforcement Bill would increase the fines for individuals and corporations for ser
Air traffic control
Air traffic control is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through controlled airspace, can provide advisory services to aircraft in non-controlled airspace. The primary purpose of ATC worldwide is to prevent collisions and expedite the flow of air traffic, provide information and other support for pilots. In some countries, ATC is operated by the military. To prevent collisions, ATC enforces traffic separation rules, which ensure each aircraft maintains a minimum amount of empty space around it at all times. Many aircraft have collision avoidance systems, which provide additional safety by warning pilots when other aircraft get too close. In many countries, ATC provides services to all private and commercial aircraft operating within its airspace. Depending on the type of flight and the class of airspace, ATC may issue instructions that pilots are required to obey, or advisories that pilots may, at their discretion, disregard; the pilot in command is the final authority for the safe operation of the aircraft and may, in an emergency, deviate from ATC instructions to the extent required to maintain safe operation of their aircraft.
Pursuant to requirements of the International Civil Aviation Organization, ATC operations are conducted either in the English language or the language used by the station on the ground. In practice, the native language for a region is used. In 1920, Croydon Airport, London was the first airport in the world to introduce air traffic control. In the United States, air traffic control developed three divisions; the first of air mail radio stations was created in 1922 after World War I when the U. S. Post Office began using techniques developed by the Army to direct and track the movements of reconnaissance aircraft. Over time, the AMRS morphed into flight service stations. Today's flight service stations do not issue control instructions, but provide pilots with many other flight related informational services, they do relay control instructions from ATC in areas where flight service is the only facility with radio or phone coverage. The first airport traffic control tower, regulating arrivals and surface movement of aircraft at a specific airport, opened in Cleveland in 1930.
Approach/departure control facilities were created after adoption of radar in the 1950s to monitor and control the busy airspace around larger airports. The first air route traffic control center, which directs the movement of aircraft between departure and destination was opened in Newark, NJ in 1935, followed in 1936 by Chicago and Cleveland; the primary method of controlling the immediate airport environment is visual observation from the airport control tower. The tower is a windowed structure located on the airport grounds. Air traffic controllers are responsible for the separation and efficient movement of aircraft and vehicles operating on the taxiways and runways of the airport itself, aircraft in the air near the airport 5 to 10 nautical miles depending on the airport procedures. Surveillance displays are available to controllers at larger airports to assist with controlling air traffic. Controllers may use a radar system called secondary surveillance radar for airborne traffic approaching and departing.
These displays include a map of the area, the position of various aircraft, data tags that include aircraft identification, speed and other information described in local procedures. In adverse weather conditions the tower controllers may use surface movement radar, surface movement guidance and control systems or advanced SMGCS to control traffic on the manoeuvring area; the areas of responsibility for tower controllers fall into three general operational disciplines: local control or air control, ground control, flight data / clearance delivery—other categories, such as Apron control or ground movement planner, may exist at busy airports. While each tower may have unique airport-specific procedures, such as multiple teams of controllers at major or complex airports with multiple runways, the following provides a general concept of the delegation of responsibilities within the tower environment. Remote and virtual tower is a system based on air traffic controllers being located somewhere other than at the local airport tower and still able to provide air traffic control services.
Displays for the air traffic controllers may be live video, synthetic images based on surveillance sensor data, or both. Ground control is responsible for the airport "movement" areas, as well as areas not released to the airlines or other users; this includes all taxiways, inactive runways, holding areas, some transitional aprons or intersections where aircraft arrive, having vacated the runway or departure gate. Exact areas and control responsibilities are defined in local documents and agreements at each airport. Any aircraft, vehicle, or person walking or working in these areas is required to have clearance from ground control; this is done via VHF/UHF radio, but there may be special cases where other procedures are used. Aircraft or vehicles without radios must respond to ATC instructions via aviation light signals or else be led by vehicles with radios. People working on the airport surface have a communications link through which they can communicate with ground control either by handheld radio or cell phone.
Ground control is vital to the smooth operation of the airport, because this position impacts th