View source for Radiosonde

{{short description|Meteorological instrumentation}}
[[File:Two modern Graw radiosondes with desktop SDR receiver.jpg|thumb|Modern radiosondes showing progress of miniaturisation]][[File: GPS sonde ready.jpg|thumb|A [[Global Positioning System|GPS]] sonde, approx 220 × 80 ×75 mm (8.7 × 3.1 × 3 in) (with grounding station in the background, used to perform a 'ground check' and also recondition the humidity sensor)]]

A '''radiosonde''' is a battery-powered [[telemetry]] instrument carried into the atmosphere usually by a [[weather balloon]] that measures various [[Atmospheric sounding|atmospheric parameters]] and transmits them by radio to a ground receiver. Modern radiosondes measure or calculate the following variables: [[altitude]], [[pressure]], [[temperature]], [[relative humidity]], [[wind]] (both [[wind speed]] and [[wind direction]]), [[cosmic ray]] readings at high altitude and [[Geographic coordinate system|geographical position]] ([[latitude]]/[[longitude]]). Radiosondes measuring [[ozone]] concentration are known as ozonesondes.<ref>{{cite web| url=http://www.ozonelayer.noaa.gov/action/ozonesonde.htm| author=Karin L. Gleason| title=Ozonesonde| work=noaa.gov| publisher=National Oceanic and Atmospheric Administration| date=March 20, 2008| access-date=2011-07-04}}</ref>

Radiosondes may operate at a [[radio frequency]] of 403 [[Hertz|MHz]] or 1680&nbsp;MHz.  A radiosonde whose position is tracked as it ascends to give wind speed and direction information is called a '''rawinsonde''' ("radar wind -sonde").<ref name="NOAA">{{cite web
 |title       = Frequently asked questions about NWS observation program
 |work        = Upper-air observation program
 |publisher   = [[National Weather Service|US National Weather Service]], [[National Oceanic and Atmospheric Administration]]
 |url         = http://www.ua.nws.noaa.gov/Faq.htm
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20141009184743/http://www.ua.nws.noaa.gov/Faq.htm
 |archive-date = 2014-10-09
}}</ref><ref name="Britannica">{{cite encyclopedia
  | title = Rawinsonde
  | encyclopedia = Encyclopædia Britannica online
  | publisher = Encyclopædia Britannica Inc. 
  | date = 2014
  | url = http://www.britannica.com/EBchecked/topic/1393995/rawinsonde
  | access-date = June 15, 2014}}</ref>  Most radiosondes have radar reflectors and are technically rawinsondes.  A radiosonde that is dropped from an airplane and falls, rather than being carried by a balloon is called a [[dropsonde]].  Radiosondes are an essential source of [[meteorological]] data, and hundreds are launched all over the world daily.

== History ==
[[File:PSM V53 D061 Train of tandem kites bearing a meteorograph.png|thumb|upright|left|Kites used to fly a meteograph]]
[[File:PSM V53 D070 Meteorograph.jpg|thumb|upright|Meteograph used by the US Weather Bureau in 1898]]
[[File:Wea01108 - Flickr - NOAA Photo Library.jpg|thumb|upright|U.S. Bureau of Standards personnel launch radiosonde near Washington, DC in 1936]]
[[File:Launching radiosonde 1943.jpg|thumb|upright|US sailors launching a radiosonde during World War 2]]

The first flights of aerological instruments were done in the second half of the 19th century with kites and [[Thermo-hygrograph|meteographs]], a recording device measuring pressure and temperature that would be recovered after the experiment. This proved difficult because the kites were linked to the ground and were very difficult to manoeuvre in gusty conditions. Furthermore, the sounding was limited to low altitudes because of the link to the ground.

[[Gustave Hermite]] and [[Georges Besançon]], from France, were the first in 1892 to use a balloon to fly the meteograph. In 1898, [[Léon Teisserenc de Bort]] organized at the ''Observatoire de Météorologie Dynamique de [[Trappes]]'' the first regular daily use of these balloons. Data from these launches showed that the temperature lowered with height up to a certain altitude, which varied with the season, and then stabilized above this altitude. De Bort's discovery of the [[tropopause]] and [[stratosphere]] was announced in 1902 at the French Academy of Sciences.<ref name="MF2">{{cite web
|url=http://www.meteo.fr/meteonet/decouvr/dossier/cnam/fr/s_rub_4_6.htm
|work=Découvrir : Mesurer l’atmosphère
|title=Radiosondage
|publisher=[[Météo-France]]
|access-date=2008-06-30
|language=fr
|url-status=dead
|archive-url=https://web.archive.org/web/20061207115202/http://www.meteo.fr/meteonet/decouvr/dossier/cnam/fr/s_rub_4_6.htm
|archive-date=2006-12-07
}}</ref> Other researchers, like [[Richard Aßmann]] and [[William Henry Dines]], were working at the same times with similar instruments.

In 1924, Colonel William Blaire in the [[Signal Corps (United States Army)|U.S. Signal Corps]] did the first primitive experiments with weather measurements from balloon, making use of the temperature dependence of radio circuits. The first true radiosonde that sent precise encoded telemetry from weather sensors was invented in France by {{Interlanguage link|Robert Bureau|fr}}. Bureau coined the name "radiosonde" and flew the first instrument on January 7, 1929.<ref name="MF2"/><ref name="MF3">{{cite web
|url=http://www.meteo.fr/meteonet/decouvr/a-z/html/224_curieux.htm
|work=La météo de A à Z > Définition
|title=Bureau (Robert)
|publisher=[[Météo-France]]
|access-date=2008-06-30
|language=fr
|url-status=dead
|archive-url=https://web.archive.org/web/20071029230225/http://www.meteo.fr/meteonet/decouvr/a-z/html/224_curieux.htm
|archive-date=2007-10-29
}}</ref> Developed independently a year later, [[Pavel Molchanov]] flew a radiosonde on January 30, 1930. Molchanov's design became a popular standard because of its simplicity and because it converted sensor readings to [[Morse code]], making it easy to use without special equipment or training.<ref name="ssht">DuBois, Multhauf and Ziegler, "The Invention and Development of the Radiosonde", ''Smithsonian Studies in History and Technology'', No. 53, 2002.</ref>

Working with a modified Molchanov sonde, Sergey Vernov was the first to use radiosondes to perform cosmic ray readings at high altitude. On April 1, 1935, he took measurements up to {{convert|13.6|km|abbr=on}} using a pair of [[Geiger counter]]s in an anti-coincidence circuit to avoid counting secondary ray showers.<ref name="ssht"/><ref>Vernoff, S. "Radio-Transmission of Cosmic Ray Data from the Stratosphere", ''Nature'', June 29, 1935.</ref> This became an important technique in the field, and Vernov flew his radiosondes on land and sea over the next few years, measuring the radiation's latitude dependence caused by the [[Earth's magnetic field]].

In 1936, the U.S. Navy assigned the [[U.S. Bureau of Standards|U.S. Bureau of Standards (NBS)]] to develop an official radiosonde for the Navy to use.<ref name=":0">{{Cite news|url=https://repository.si.edu/bitstream/handle/10088/2453/SSHT-0053_Lo_res.pdf?sequence=2&isAllowed=y|title=The Invention and Development of the Radiosonde, with a Catalog of Upper-Atmospheric Telemetering Probes in the National Museum of American History, Smithsonian Institution|last1=DuBois|first1=John|date=2002|access-date=July 13, 2018|publisher=Smithsonian Institution Press|last2=Multhauf|first2=Robert|last3=Ziegler|first3=Charles}}</ref> The NBS gave the project to [[Harry Diamond (engineer)|Harry Diamond]], who had previously worked on radio navigation and invented a blind landing system for airplanes.<ref>{{Cite journal|last=Gillmor|first=Stewart|date=December 26, 1989|title=Seventy Years of Radio Science, Technology, Standards, and Measurement at the National Bureau of Standards|journal=Eos, Transactions American Geophysical Union|volume=70|issue=52|pages=1571|doi=10.1029/89EO00403|bibcode=1989EOSTr..70.1571G}}</ref> The organization led by Diamond eventually (in 1992) became a part of the [[United States Army Research Laboratory|U.S. Army Research Laboratory]]. In 1937, Diamond, along with his associates Francis Dunmore and Wilbur Hinmann, Jr., created a radiosonde that employed audio-frequency subcarrier modulation with the help of a resistance-capacity relaxation oscillator. In addition, this NBS radiosonde was capable of measuring temperature and humidity at higher altitudes than conventional radiosondes at the time due to the use of electric sensors.<ref name=":0" /><ref name=":1">{{Cite journal|last=Clarke|first=E.T.|date=September 1941|title=The radiosonde: The stratosphere laboratory|journal=Journal of the Franklin Institute|volume=232|issue=3|pages=217–238|doi=10.1016/S0016-0032(41)90950-X}}</ref>

In 1938, Diamond developed the first ground receiver for the radiosonde, which prompted the first service use of the NBS radiosondes in the Navy. Then in 1939, Diamond and his colleagues developed a ground-based radiosonde called the “remote weather station,” which allowed them to automatically collect weather data in remote and inhospitable locations.<ref name=":2">{{Cite book|url=https://books.google.com/books?id=hrizEY2BWOoC&pg=PA42|title=A Century of Excellence in Measurements, Standards, and Technology|last=Lide|first=David|publisher=CRC Press|year=2001|isbn=978-0-8493-1247-2|page=42}}</ref> By 1940, the NBS radiosonde system included a pressure drive, which measured temperature and humidity as functions of pressure.<ref name=":0" /> It also gathered data on cloud thickness and light intensity in the atmosphere.<ref>{{Cite web|url=http://nistdigitalarchives.contentdm.oclc.org/cdm/singleitem/collection/p16009coll19/id/1458/rec/11|title=NBS radio meteorographs :: Historic Photographs Collection|website=nistdigitalarchives.contentdm.oclc.org|access-date=2018-07-13}}</ref> Due to this and other improvements in cost (about $25), weight (> 1 kilogram), and accuracy, hundreds of thousands of NBS-style radiosondes were produced nationwide for research purposes, and the apparatus was officially adopted by the U.S. Weather Bureau.<ref name=":0" /><ref name=":1" />

Diamond was given the Washington Academy of Sciences Engineering Award in 1940 and the IRE Fellow Award (which was later renamed the Harry Diamond Memorial Award) in 1943 for his contributions to radio-meteorology.<ref name=":2" /><ref>{{Cite web|url=https://ieeeusa.org/volunteers/awards-recognition/technical-achievement-awards/harry-diamond-award/harry-diamond-award-recipients/|title=Harry Diamond Memorial Award - Past Recipients - IEEE-USA|website=ieeeusa.org|language=en-US|access-date=2018-07-13|archive-date=2018-07-13|archive-url=https://web.archive.org/web/20180713175908/https://ieeeusa.org/volunteers/awards-recognition/technical-achievement-awards/harry-diamond-award/harry-diamond-award-recipients/|url-status=dead}}</ref>

The expansion of economically important government [[weather forecasting]] services during the 1930s and their increasing need for data motivated many nations to begin regular radiosonde observation programs

In 1985, as part of the [[Soviet Union]]'s [[Vega program]], the two [[Venus]] probes, [[Vega 1]] and [[Vega 2]], each dropped a radiosonde into the [[atmosphere of Venus]]. The sondes were tracked for two days.

Although modern [[remote sensing]] by satellites, aircraft and ground sensors is an increasing source of atmospheric data, none of these systems can match the vertical resolution ({{convert|30|m|abbr=on}} or less) and altitude coverage ({{convert|30|km|abbr=on}}) of radiosonde observations, so they remain essential to modern meteorology.<ref name="NOAA"/>

Although hundreds of radiosondes are launched worldwide each day year-round, fatalities  attributed to  radiosondes are rare. The first known example was the electrocution of a lineman in the United States who was attempting to free a radiosonde from high-tension power lines in 1943.<ref>"Linemen Cautioned About Disengaging Radiosonde," Electrical World, 15 May 1943</ref><ref>{{Cite web |url=http://radiosondemuseum.com/wp-content/gallery/mags/1943-radiosonde-fatality.jpg |title = 1943-radiosonde-fatality.JPG (758x1280 pixels) |archive-url=https://archive.today/20130208172229/http://radiosondemuseum.com/wp-content/gallery/mags/1943-radiosonde-fatality.jpg |archive-date=8 February 2013 |url-status=dead}}</ref> In 1970, an [[Antonov 24]] operating [[Aeroflot Flight 1661]] suffered a loss of control after striking a radiosonde in flight resulting in the death of all 45 people on board.

== Operation ==
A [[rubber]] or [[latex]] balloon filled with either [[helium]] or [[hydrogen]] lifts the device up through the [[Atmosphere of Earth|atmosphere]]. The maximum altitude to which the balloon ascends is determined by the diameter and thickness of the balloon. Balloon sizes can range from {{convert|100|to|3000|g|abbr=on}}. As the balloon ascends through the atmosphere, the pressure decreases, causing the balloon to expand. Eventually, the balloon will expand to the extent that its skin will break, terminating the ascent. An {{convert|800|g|abbr=on}} balloon will burst at about {{convert|21|km|abbr=on}}.<ref>Dian J. Gaffen. [http://www.aero.jussieu.fr/~sparc/News12/Radiosondes.html Radiosonde Observations and Their Use in SPARC-Related Investigations.] {{webarchive |url=https://web.archive.org/web/20070607142822/http://www.aero.jussieu.fr/~sparc/News12/Radiosondes.html |date=June 7, 2007 }} Retrieved on 2008-05-25.</ref>  After bursting, a small [[parachute]] on the radiosonde's support line may slow its descent to Earth, while some rely on the aerodynamic drag of the shredded remains of the balloon, and the very light weight of the package itself.  A typical radiosonde flight lasts 60 to 90 minutes.  One radiosonde from [[Clark Air Base]], Philippines, reached an altitude of {{convert|155092|ft|abbr=on}}.

The modern radiosonde communicates via radio with a computer that stores all the variables in real time. The first radiosondes were observed from the ground with a [[theodolite]], and gave only a wind estimation by the position. With the advent of radar by the Signal Corps it was possible to track a radar target carried by the balloons with the [[SCR-658 radar]]. Modern radiosondes can use a variety of mechanisms for determining wind speed and direction, such as a [[radio direction finder]] or [[Global Positioning System|GPS]]. The weight of a radiosonde is typically {{convert|250|g|abbr=on}}.

Sometimes radiosondes are deployed by being dropped from an aircraft instead of being carried aloft by a balloon. Radiosondes deployed in this way are called [[dropsonde]]s.

== Routine radiosonde launches ==
Radiosondes weather balloons have conventionally been used as means of measuring atmospheric profiles of humidity, temperature, pressure, wind speed and direction.<ref name="radio2022">{{cite journal |last1=Ding |first1=Tong |last2=Awange |first2=Joseph L. |last3=Scherllin-Pirscher |first3=Barbara |last4=Kuhn |first4=Michael |last5=Anyah |first5=Richard |last6=Zerihun |first6=Ayalsew |last7=Bui |first7=Luyen K. |title=GNSS Radio Occultation Infilling of the African Radiosonde Data Gaps Reveals Drivers of Tropopause Climate Variability |url=https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022JD036648 |journal=Journal of Geophysical Research: Atmospheres |date=16 September 2022 |volume=127 |issue=17 |doi=10.1029/2022JD036648|bibcode=2022JGRD..12736648D |s2cid=251652497 |hdl=20.500.11937/91903 |hdl-access=free }}{{Creative Commons text attribution notice|cc=by4|from this source=yes}}</ref> High-quality, spatially and temporally “continuous” data from upper-air monitoring along with surface observations are critical bases for understanding weather conditions and climate trends and providing weather and climate information for the welfare of societies. Reliable and timely information underpin society’s preparedness to extreme weather conditions and to changing climate patterns.<ref name="radio2022" />

Worldwide, there are about 1,300 radiosonde launch sites.<ref>[http://www.wmo.int/pages/prog/www/OSY/Gos-components.html#upper WMO Global Observing System]''Upper-air observations''. Retrieved February 19, 2017.</ref> Most countries share data with the rest of the world through international agreements. Nearly all routine radiosonde launches occur one hour before the official observation times of 0000 [[Coordinated Universal Time|UTC]] and 1200 UTC to center the observation times during the roughly two-hour ascent.<ref>[https://www.weather.gov/media/key/Weather-Balloons.pdf Weather Balloons!] Retrieved 1 January 2023.</ref><ref name="auto">[https://www.weather.gov/jetstream/radiosondes Radiosondes] Retrieved 1 January 2023.</ref> Radiosonde observations are important for [[weather forecasting]], [[severe weather]] [[Severe weather terminology (United States)|watches and warnings]], and atmospheric research. 

The [[United States]] [[National Weather Service]] launches radiosondes twice daily from 92 stations, 69 in the conterminous United States, 13 in Alaska, nine in the Pacific, and one in Puerto Rico. It also supports the operation of 10 radiosonde sites in the [[Caribbean]].<ref name="auto"/>
A list of U.S. operated land based launch sites can be found in Appendix C, U.S. Land-based Rawinsonde Stations<ref>[http://www.ofcm.gov/fmh3/pdf/11-app-c.pdf U.S. Land-based Rawinsode Stations] {{webarchive |url=https://web.archive.org/web/20160303235131/http://www.ofcm.gov/fmh3/pdf/11-app-c.pdf |date=March 3, 2016 }}</ref> of the Federal Meteorological Handbook #3,<ref>{{cite web |url=http://www.ofcm.gov/fmh3/text/default.htm |title=Federal Meteorological Handbook #3 |publisher=Ofcm.gov |access-date=2013-09-15 |url-status=dead |archive-url=https://web.archive.org/web/20131222081748/http://www.ofcm.gov/fmh3/text/default.htm |archive-date=2013-12-22 }}</ref> titled Rawinsonde and Pibal Observations, dated May 1997.

The [[UK]] launches [[Vaisala]] RS41 radiosondes<ref>[https://blog.metoffice.gov.uk/2017/10/27/did-you-know-were-testing-new-weather-balloons-from-cornwall-to-antarctica/ Did You Know? We’re testing new weather balloons: from Cornwall to Antarctica!] Retrieved 1 January 2023.</ref>
four times daily (an hour before 00, 06, 12, and 18 UTC) from 6 launch sites (south to north):  [[Camborne]], (lat,lon)=(50.218, -5.327), SW tip of England; [[Herstmonceux]] (50.89, 0.318), near SE coast; [[Watnall]], (53.005, -1.25), central England; Castor Bay, (54.50, -6.34), near the SE corner of [[Lough Neagh]] in Northern Ireland; [[Albemarle Barracks, England|Albemarle]], (55.02, -1.88), NE England; and [[Lerwick]], (60.139, -1.183), [[Shetland]], [[Scotland]]. <ref>[https://www.metoffice.gov.uk/services/business-industry/energy/safeguarding Protecting our observing capability] Retrieved 1 January 2023.</ref>
<ref>[https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-synoptic-and-climate-stations Synoptic and climate stations] Retrieved 1 January 2023.</ref>

== Uses of upper air observations ==
Raw upper air data is routinely processed by supercomputers running numerical models. Forecasters often view the data in a graphical format, plotted on [[thermodynamic diagrams]] such as [[Skew-T log-P diagram]]s, [[Tephigram]]s, and or [[Stüve diagram]]s, all useful for the interpretation of the atmosphere's vertical [[thermodynamics]] profile of temperature and moisture as well as [[kinematics]] of vertical wind profile.<ref name="radio2022"/>

Radiosonde data is a crucially important component of numerical weather prediction. Because a sonde may drift several hundred kilometers during the 90- to 120-minute flight, there may be concern that this could introduce problems into the model initialization. <ref name="radio2022" /> However, this appears not to be so except perhaps locally in [[jet stream]] regions in the stratosphere.<ref>{{cite journal|first1=Ray|last1=McGrath|first2=Tido|last2=Semmler|first3=Conor|last3=Sweeney |first4=Shiyu|last4=Wang|date=15 Jul 2006|title=Impact of Balloon Drift Errors in Radiosonde Data on Climate Statistics |journal=Journal of Climate|volume=19|issue=14|pages=3430–3442|doi=10.1175/JCLI3804.1|bibcode=2006JCli...19.3430M |doi-access=free}}</ref> This issue may in future be solved by [[Weather drone|weather drones]], which have precise control over their location and can compensate for drift.<ref>{{Cite journal |last1=Bell |first1=Tyler M. |last2=Greene |first2=Brian R. |last3=Klein |first3=Petra M. |last4=Carney |first4=Matthew |last5=Chilson |first5=Phillip B. |date=2020-07-16 |title=Confronting the boundary layer data gap: evaluating new and existing methodologies of probing the lower atmosphere |url=https://amt.copernicus.org/articles/13/3855/2020/ |journal=Atmospheric Measurement Techniques |language=English |volume=13 |issue=7 |pages=3855–3872 |doi=10.5194/amt-13-3855-2020 |bibcode=2020AMT....13.3855B |issn=1867-1381|doi-access=free }}</ref>

Lamentably, in less developed parts of the globe such as Africa, which has high vulnerability to impacts of extreme weather events and climate change, there is paucity of surface- and upper-air observations. The alarming state of the issue was highlighted in 2020 by the [[World Meteorological Organisation]]<ref>{{cite news |title=The gaps in the Global Basic Observing Network (GBON) |url=https://library.wmo.int/doc_num.php?explnum_id=10377}}</ref> which stated that "the situation in Africa shows a dramatic decrease of almost 50% from 2015 to 2020 in the number of radiosonde flights, the most important type of surface-based observations. Reporting now has poorer geographical coverage". Over the last two decades, some 82% of the countries in Africa have experienced severe (57%) and moderate (25%) radiosonde data gap.<ref name="radio2022" /> This dire situation has prompted call for urgent need to fill the data gap in Africa and globally. The vast data gap in such a large part the global landmass, home to some of the most vulnerable societies, the aforementioned call has galvanised a global effort<ref>{{cite news |title=How plugging data gaps will transform our response to climate change |url=https://www.scmp.com/comment/opinion/article/3154116/cop26-how-plugging-data-gaps-will-transform-our-response-climate |work=South China Morning Post |date=31 October 2021 |language=en}}</ref> to “plug the data gap” in the decade ahead and halt a further deterioration in the observation networks.

==International regulation==

According to the [[International Telecommunication Union]], a '''meteorological aids service''' (also: ''meteorological aids radiocommunication service'') is – according to ''Article 1.50'' of the [[ITU Radio Regulations]] (RR)<ref>ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.50, definition: ''meteorological aids service / meteorological aids radiocommunication service''</ref> – defined as ''"A [[radiocommunication service]] used for meteorological, including hydrological, observations and exploration.''
Furthermore, according to ''article 1.109'' of the ITU RR:<ref>ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.109, definition: ''radiosonde''</ref> 
{{blockquote|A radiosonde is an automatic [[radio transmitter]] in the [[meteorological aids service]] usually carried on an [[aircraft]], [[weather balloon|free balloon]], kite or parachute, and which transmits meteorological data. Each ''radio transmitter'' shall be classified by the ''radiocommunication service '' in which it operates permanently or temporarily.}}

===Frequency allocation===
The allocation of radio frequencies is provided according to ''Article 5'' of the ITU Radio Regulations (edition 2012).<ref>''ITU Radio Regulations, CHAPTER II – Frequencies, ARTICLE 5 Frequency allocations, Section IV – Table of Frequency Allocations''</ref>

In order to improve harmonisation in spectrum utilisation, the majority of service-allocations stipulated in this document were incorporated in national Tables of Frequency Allocations and Utilisations which is with-in the responsibility of the appropriate national administration. The allocation might be primary, secondary, exclusive, and shared.
*primary allocation:  is indicated by writing in capital letters (see example below)
*secondary allocation: is indicated by small letters
*exclusive or shared utilization: is within the responsibility of administrations 
However, military usage, in bands where there is civil usage, will be in accordance with the ITU Radio Regulations.

; Example of [[frequency allocation]]:
{| class=wikitable
|- bgcolor="#CCCCCC" align="center"
|align="center" colspan="3"| '''Allocation to services'''
|- align="center"
| [[International Telecommunication Union region|Region 1]] || Region 2 || Region 3
|-
|colspan="3"|401-402 MHz &nbsp;&nbsp; &nbsp;&nbsp; '''METEOROLOGICAL AIDS'''<br />
::::: SPACE OPERATION (space-to-Earth) <br />EARTH EXPLORATION-SATELLITE (Earth-to-space) <br />METEOROLOGICAL-SATELLITE (Earth-to-space)<br />Fixed <br />Mobile except aeronautical mobile
|-
|}

== See also ==
* [[6AK5]]
* [[Atmospheric model]]
* [[Atmospheric thermodynamics]]
* [[CTD (instrument)]]
* [[Global horizontal sounding technique]]
* [[Rocketsonde]]
* [[Totex]] - a Japanese manufacturer of meteorological balloons
* [[Vaisala]]
* [[Vilho Väisälä]]
* [[Water-activated battery]]
* [[Cricketsonde]]

==References==
{{reflist}}

== External links ==
{{Commons|Radiosonde}}
* [http://weather.uwyo.edu/upperair/sounding.html Upper air data for the world - past and present]
* [http://www.wmo.int/pages/prog/www/ois/volume-a/vola-home.htm WMO spreadsheet of all Upper Air stations around the world]
* [http://www.stuffintheair.com/first-law-thermodynamics.html Interpreting radiosonde data] Tephigrams and Skew-T log P diagrams.
* [http://radiosondemuseum.org/ Radiosonde Museum of North America]
* [http://www.webmet.com/met_monitoring/912.html Radiosonde Sounding System at webmet.com]
* [https://web.archive.org/web/20160220121505/http://www.ua.nws.noaa.gov/factsheet.htm NOAA National Weather Service Radiosonde Factsheet]
* [https://web.archive.org/web/20121029020205/http://www.sinp.msu.ru/eng/maininc/vernov.html Sergei Nikolaevich Vernov]
* [http://www.photolib.noaa.gov/htmls/wea01200.htm SCR-658 pics]
* [https://web.archive.org/web/20081121225613/http://6thweathermobile.org/1949_(part%201).htm early pics]
* [http://nistdigitalarchives.contentdm.oclc.org/cdm/ref/collection/p15421coll3/id/565 Photo - Early Type Radiosonde]
* [http://nistdigitalarchives.contentdm.oclc.org/cdm/ref/collection/p15421coll3/id/200 Photo - Radiosonde, Transistor Type]
{{Radio station ITU}}

{{Meteorological equipment}}
{{Authority control}}

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