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44-474: The most common type of high-altitude balloons are weather balloons . Other purposes include use as a platform for experiments in the upper atmosphere. Modern balloons generally contain electronic equipment such as radio transmitters , cameras , or satellite navigation systems, such as GPS receivers. Hobbyists frequently purchase weather balloons because of their ease of use, low price point, and widespread commoditisation. These balloons are launched into what

88-549: A GPS receiver, an APRS encoder, and a radio transmitter module. Other experimental payload modules include an Amateur Radio crossband repeater, and a digital camera , all of which is contained within an insulated foam box suspended below the balloon. A BalloonSat is a simple package designed to carry lightweight experiments into near space. They are a popular introduction to engineering principles in some high school and college courses. BalloonSats are carried as secondary payloads on ARHAB flights. One reason BalloonSats are simple

132-598: A Global Positioning System (GPS) receiver and converts it to a digital radio transmission. Other flights may use an analog beacon and are tracked using radio direction finding techniques. Long duration flights frequently must use high frequency custom-built transmitters and slow data protocols such as radioteletype (RTTY), Hellschreiber , Morse code , and PSK31 , to transmit data over great distances using little battery power. The use of amateur radio transmitters on an ARHAB flight requires an amateur radio license, but non-amateur radio transmitters are possible to use without

176-438: A 160 kbit/s raw data rate operates at 120 kBd.) Codes with many symbols, and thus a bit rate higher than the symbol rate, are most useful on channels such as telephone lines with a limited bandwidth but a high signal-to-noise ratio within that bandwidth. In other applications, the bit rate is less than the symbol rate. Eight-to-fourteen modulation as used on audio CDs has bit rate ⁠ 8 / 17 ⁠ of

220-483: A constant altitude for long periods of time to help diagnose radioactive debris from atomic fallout, were experimented with in 1958. The drone technology boom has led to the development of weather drones since the late 1990s. These may begin to replace balloons as a more specific means for carrying radiosondes. The balloon itself produces the lift , and is usually made of a highly flexible latex material, though chloroprene may also be used. The unit that performs

264-470: A high-altitude balloon. Geostationary balloon satellites ( GBS ) are proposed high-altitude balloons that would float in the mid- stratosphere (60,000 to 70,000 feet (18 to 21 km) above sea level) at a fixed point over the Earth's surface and thereby act as an atmospheric satellite . At those altitudes, air density is around 1/15 to 1/20 of what it is at sea level . The average wind speed at these levels

308-582: A license. In addition to the tracking equipment, other payload components may include sensors, data loggers, cameras, amateur television (ATV) transmitters or other scientific instruments. Some ARHAB flights carry a simplified payload package called BalloonSat . A typical ARHAB flight uses a standard latex weather balloon, lasts around 2–3 hours, and reaches 25–35 km (16–22 mi) in altitude. Experiments with zero-pressure balloons , superpressure balloons , and valved latex balloons have extended flight times to more than 24 hours. A zero-pressure flight by

352-581: A measure of the gross bit rate R as Here, the ⌈ x ⌉ {\displaystyle \left\lceil x\right\rceil } denotes the ceiling function of x {\displaystyle x} , where x {\displaystyle x} is taken to be any real number greater than zero, then the ceiling function rounds up to the nearest natural number (e.g. ⌈ 2.11 ⌉ = 3 {\displaystyle \left\lceil 2.11\right\rceil =3} ). In that case, M = 2 different symbols are used. In

396-449: A modem, these may be time-limited sinewave tones with unique combinations of amplitude, phase and/or frequency. For example, in a 64QAM modem, M = 64 , and so the bit rate is N = log 2 (64) = 6 times the baud rate. In a line code, these may be M different voltage levels. The ratio is not necessarily an integer; in 4B3T coding, the bit rate is ⁠ 4 / 3 ⁠ of the baud rate. (A typical basic rate interface with

440-652: A significant threat to marine ecosystems. Studies have shown that a substantial portion of weather balloons eventually end up in the ocean. For instance, one Australian researcher collected over 2,460 weather balloon debris from the Great Barrier Reef , estimating that up to 300 balloons per week may be released into the marine environment. This environmental impact underscores the need for sustainable alternatives in weather data collection. Scientists and environmentalists have raised concerns about weather balloons' environmental impact. The latex material, which can persist in

484-427: A small, expendable measuring device called a radiosonde . To obtain wind data, they can be tracked by radar , radio direction finding , or navigation systems (such as the satellite-based Global Positioning System , GPS). Balloons meant to stay at a constant altitude for long periods of time are known as transosondes . Weather balloons that do not carry an instrument pack are used to determine upper-level winds and

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528-456: A symbol may have more than two states, so it may represent more than one bit . A bit (binary digit) always represents one of two states. If N bits are conveyed per symbol, and the gross bit rate is R , inclusive of channel coding overhead, the symbol rate f s can be calculated as By taking information per pulse N in bit/pulse to be the base-2- logarithm of the number of distinct messages M that could be sent, Hartley constructed

572-427: Is a common unit of measurement of symbol rate , which is one of the components that determine the speed of communication over a data channel . It is the unit for symbol rate or modulation rate in symbols per second or pulses per second . It is the number of distinct symbol changes (signalling events) made to the transmission medium per second in a digitally modulated signal or a bd rate line code . Baud

616-464: Is a series of Canadian-based high-altitude balloon experiments by a group of Amateur Radio operators and experimenters from Sherwood Park and Edmonton, Alberta. The experiments started in the year 2000 and continued with BEAR-9 in 2012, reaching 36.010 km (22.376 mi). The balloons are made of latex filled with either helium or hydrogen . All of the BEAR payloads carry a tracking system comprising

660-504: Is defined as " near space ", defined as the area of Earth's atmosphere between the Armstrong limit (18–19 km (11–12 mi) above sea level), where pressure falls to the point that a human being cannot survive without a pressurised suit, and the Kármán line (100 km (62 mi) above sea level), where astrodynamics must take over from aerodynamics in order to maintain flight. Due to

704-450: Is less than that at the surface. A propulsion system would allow the balloon to move into and maintain its position. The GBS would be powered with solar panels. A GBS could be used to provide broadband Internet access over a large area. Laser broadband would connect the GBS to the network , which could then provide a large area of coverage because of its wider line of sight over the curvature of

748-857: Is part of a course taught by Space Grant at the University of Colorado at Boulder. Often the design of a BalloonSat is under weight and volume constraints. This encourages good engineering practices, introduces a challenge, and allows for the inclusion of many BalloonSats on an ARHAB flight. The airframe material is usually Styrofoam or Foamcore, as they are lightweight, easy to machine, and provide reasonably good insulation. Most carry sensors, data loggers and small cameras operated by timer circuits. Popular sensors include air temperature, relative humidity, tilt, and acceleration. Experiments carried inside BalloonSats have included such things as captive insects and food items. Before launch, most BalloonSats are required to undergo testing. These tests are designed to ensure

792-449: Is related to gross bit rate , which can be expressed in bits per second (bit/s). If there are precisely two symbols in the system (typically 0 and 1), then baud and bits per second are equivalent. The baud unit is named after Émile Baudot , the inventor of the Baudot code for telegraphy , and is represented according to the rules for SI units . That is, the first letter of its symbol

836-409: Is related to gross bit rate expressed in bit/s. The term baud has sometimes incorrectly been used to mean bit rate , since these rates are the same in old modems as well as in the simplest digital communication links using only one bit per symbol, such that binary digit "0" is represented by one symbol, and binary digit "1" by another symbol. In more advanced modems and data transmission techniques,

880-546: Is that they do not require the inclusion of tracking equipment; as secondary payloads, they already are being carried by tracking capsules. Space Grant started the BalloonSat program in August 2000. It was created as a hands-on way to introduce new science and engineering students interested in space studies to some fundamental engineering techniques, team working skills and the basics of space and Earth science. The BalloonSat program

924-404: Is the application of analog and digital amateur radio to weather balloons and was the name suggested by Ralph Wallio (amateur radio callsign W0RPK) for this hobby. Often referred to as "The Poor Man's Space Program", ARHAB allows amateurs to design functioning models of spacecraft and launch them into a space-like environment. Bill Brown (amateur radio callsign WB8ELK) is considered to have begun

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968-559: Is uppercase (Bd), but when the unit is spelled out, it should be written in lowercase (baud) except when it begins a sentence or is capitalized for another reason, such as in title case. It was defined by the CCITT (now the ITU ) in November 1926. The earlier standard had been the number of words per minute, which was a less robust measure since word length can vary. The symbol duration time, also known as

1012-651: The Mediterranean Sea . The flight lasted 57 hours and 2 minutes. It became the first successful U.S. transcontinental and the first successful transatlantic amateur radio high-altitude balloon. Since that time, a number of flights have circumnavigated the Earth using superpressure plastic film balloons. Each year in the United States, the Great Plains Super Launch (GPSL) hosts a large gathering of ARHAB groups. Balloon Experiments with Amateur Radio (BEAR)

1056-568: The Spirit of Knoxville Balloon Program in March 2008 lasted over 40 hours and landed off the coast of Ireland, over 5,400 km (3,400 mi) from its launch point. On December 11, 2011, the California Near Space Project flight number CNSP-11 with the call sign K6RPT-11 launched a record-breaking flight traveling 6,236 mi (10,036 km) from San Jose, California , to a splashdown in

1100-399: The unit interval , can be directly measured as the time between transitions by looking at an eye diagram of the signal on an oscilloscope . The symbol duration time T s can be calculated as: where f s is the symbol rate. There is also a chance of miscommunication which leads to ambiguity. The baud is scaled using standard metric prefixes , so that for example The symbol rate

1144-831: The 12-hour routine launches in which time much can change in the atmosphere. Military and civilian government meteorological agencies such as the National Weather Service in the US typically launch balloons, and by international agreements, almost all the data are shared with all nations. Specialized uses also exist, such as for aviation interests, pollution monitoring, photography or videography, and research. Examples include pilot balloons (Pibal). Field research programs often use mobile launchers from land vehicles as well as ships and aircraft (usually dropsondes in this case). In recent years, weather balloons have also been used for scattering human ashes at high altitudes. The weather balloon

1188-516: The BalloonSat crew can prepare the BalloonSat at the launch site. Besides conducting scientific activities, schools, influencers and other individuals have launched a wide variety of novelty payloads to the stratosphere with high-altitude balloons. These have included teddy bears, LEGO figurines, hamburgers, pizza, Cornish pasties , garlic bread , bacon and cans of beer. Japanese electronics manufacturer Toshiba attempted to record an advertisement in near space with an armchair and cameras tethered to

1232-418: The BalloonSat will function properly and return science results. The tests include a cold soak, drop test, function test, and weighing. The cold soak test simulates the intense cold temperatures the BalloonSat will experience during its mission. A launch and landing can be traumatic, therefore the drop test requires the BalloonSat to hold together and still function after an abrupt drop. The function test verifies

1276-519: The Earth and unimpeded Fresnel zone . World View Enterprises built and operates a balloon spaceport (high-altitude balloon port) in Pima County, Arizona . Weather balloon A weather balloon , also known as a sounding balloon , is a balloon (specifically a type of high-altitude balloon ) that carries instruments to the stratosphere to send back information on atmospheric pressure , temperature , humidity and wind speed by means of

1320-1075: The Soviet Osoaviakhim-1 at 22,000 m (22.0 km), and the American Explorer II at 22,066 m (22.1 km). Notable crewed high altitude balloon flights include three records set for highest skydive: Uncrewed high-altitude balloons are used as research balloons , for educational purposes, and by hobbyists. Common uses include meteorology, atmospheric and climate research, collection of imagery from near space, amateur radio applications, and submillimetre astronomy . High-altitude balloons have been considered for use in telecommunications and space tourism . Private companies such as Zero 2 Infinity , Space Perspective , Zephalto , and World View Enterprises are developing both crewed and uncrewed high-altitude balloons for scientific research, commercial purposes, and space tourism. High-altitude platform stations have been proposed for applications such as communications relays. In many countries,

1364-414: The actual measurements and radio transmissions hangs at the lower end of the string, and is called a radiosonde . Specialized radiosondes are used for measuring particular parameters, such as determining the ozone concentration. The balloon is usually filled with hydrogen , though helium – a more expensive, but viable option nonetheless – is also frequently used. The ascent rate can be controlled by

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1408-568: The amount of gas with which the balloon is filled. Weather balloons may reach altitudes of 40 km (25 mi) or more, limited by diminishing pressures causing the balloon to expand to such a degree (typically by a 100:1 factor) that it disintegrates. In this instance the instrument package is usually lost, although a parachute may be employed to help in allowing retrieval of the instrument. Above that altitude sounding rockets are used to carry instruments aloft, and for even higher altitudes satellites are used. Weather balloons are launched around

1452-401: The atmosphere to collect meteorological data. The United States, for example, releases approximately 76,600 balloons annually, while Canada launches 22,000. Weather balloons, after reaching an altitude of approximately 35 kilometers, burst, releasing their instruments and the latex material they are made of. While the instruments are often recovered, the latex remains in the environment, posing

1496-557: The bureaucratic overhead required for high altitude balloon launches is minimal when the payload is below a certain weight threshold, typically on the order of a few kilograms. This makes the process of launching these small HABs accessible to many students and amateur groups. Despite their smaller size, these HABs still often ascend to (and past) altitudes on the order of 30,000 m (98,000 ft), providing easy stratospheric access for scientific and educational purposes. These amateur balloon flights are often informed in their operations by

1540-515: The globe do routine releases, two or four times daily. One of the first people to use weather balloons was the French meteorologist Léon Teisserenc de Bort . Starting in 1896 he launched hundreds of weather balloons from his observatory in Trappes , France. These experiments led to his discovery of the tropopause and stratosphere . Transosondes, weather balloons with instrumentation meant to stay at

1584-586: The ground station. Smaller packages called micro or pico trackers are also built and run under smaller balloons. These smaller trackers have used Morse code , Field Hell , and RTTY to transmit their locations and other data. The first recorded amateur radio high-altitude balloon launches took place in Finland by the Ilmari program on May 28, 1967, and in Germany in 1964. Amateur radio high-altitude ballooning ( ARHAB )

1628-458: The height of cloud layers. For such balloons, a theodolite or total station is used to track the balloon's azimuth and elevation, which are then converted to estimated wind speed and direction and/or cloud height, as applicable. Weather balloons are launched around the world for observations used to diagnose current conditions as well as by human forecasters and computer models for weather forecasting . Between 900 and 1,300 locations around

1672-675: The low cost of GPS and communications equipment, high-altitude ballooning is a popular hobby , with organizations such as UKHAS assisting the development of payloads. In France during 1783, the first public experiment with hydrogen-filled balloons involved Jacques Charles , a French professor of physics, and the Robert brothers , renowned constructors of physics instruments. Charles provided large quantities of hydrogen , which had only been produced in small quantities previously, by mixing 540 kg (1,190 lb) of iron and 270 kg (600 lb) of sulfuric acid . The balloon took 5 days to fill and

1716-443: The modern ARHAB movement with his first launch of a balloon carrying an amateur radio transmitter on 15 August 1987. An ARHAB flight consists of a balloon, a recovery parachute, and a payload of one or more packages. The payload normally contains an amateur radio transmitter that permits tracking of the flight to its landing for recovery. Most flights use an Automatic Packet Reporting System (APRS) tracker which gets its position from

1760-508: The ocean for extended periods, can harm marine life, including sea turtles , birds, and fish. Efforts to minimize the environmental impact of weather balloons include developing biodegradable materials and improved recovery methods. However, the continued reliance on weather balloons for meteorological data challenges balancing the need for accurate weather forecasts with environmental sustainability. Baud In telecommunications and electronics , baud ( / b ɔː d / ; symbol: Bd )

1804-430: The use of a path predictor. Before launch, weather forecasts containing predicted wind vectors are used to numerically propagate a simulated HAB along a trajectory, predicting where the actual balloon will travel. Testing radio range is often a large component of these hobbies. Amateur radio is often used with packet radio to communicate with 1200 baud , using a system called Automatic Packet Reporting System back to

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1848-423: The world for observations used to diagnose current conditions as well as by human forecasters and computer models for weather forecasting . Between 900 and 1,300 locations around the globe do routine releases, two or four times daily, usually at 0000 UTC and 1200 UTC. Some facilities will also do occasional supplementary special releases when meteorologists determine there is a need for additional data between

1892-577: Was also used to create the fictional entity 'Rover' during the production of the 1960s TV series The Prisoner in Portmeirion, Gwynedd, North Wales, UK in September 1966. This was retained in further scenes shot at MGM Borehamwood UK during 1966–67. While weather forecasting is increasingly reliant on satellites and radar technology, it still heavily involves the use of weather balloons. These devices, launched from thousands of stations worldwide, ascend into

1936-517: Was launched from Champ de Mars in Paris where 300,000 people gathered to watch the spectacle. The balloon was launched and rose through the clouds. The expansion of the gas caused the balloon to tear and it descended 45 minutes later 20 km (12 mi) away from Paris. Crewed high-altitude balloons have been used since the 1930s for research and in seeking flight altitude records , including Auguste Piccard's flights up to 16,201 m (16.2 km),

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