text:
Sultan Murad

Sultan Murad may refer to:

Rulers

 * Sultan Murad (Aq Qoyunlu)
 * Murad I
 * Murad II
 * Murad III
 * Murad IV
 * Murad V

Armed groups

 * Sultan Murad Division

title: Sultan Murad


text:
Andrey Bogolyubsky

Andrey Bogolyubsky (died 28 June 1174; Андрей Ю́рьевич Боголюбский, lit. Andrey Yuryevich of Bogolyubovo), was Prince of Vladimir-Suzdal from 1157 until his death. During repeated internecine wars between the princely clans, Andrey accompanied his father Yuri Dolgorukiy during a brief capture of Kiev in 1149. 20 years later, his son led the Sack of Kiev (1169). He made efforts to elevate Vladimir on the Klyazma as the new centre of Kievan Rus'. He was canonized as a saint in the Russian Orthodox Church in 1702.

Biography
Andrey Bogolyubsky was born ca. 1111, to a daughter of Ayyub Khan, the Kipchak leader, and to Yuri I Vladimirovich (Юрий Владимирович), commonly known as Yuri Dolgoruki (Юрий Долгорукий). Yuri was a son of Volodimer II Monomakh, progenitor of the Monomakhovichi. Yuri proclaimed Andrey a prince in Vyshgorod (near Kiev).

Andrey left Vyshgorod in 1155 and moved to Vladimir, a little town on the river Klyazma founded in 1108. After his father's death in 1157, he became Knyaz (prince) of Vladimir, Rostov and Suzdal.

Construction works
He commenced the construction of fortifications around the town of Vladimir in 1158 (completed in 1164), as well as the Dormition Cathedral in Vladimir. In 1162, Andrey sent an embassy to Constantinople, lobbying for a separate metropolitan see in Vladimir. Fortifications around Vladimir were completed in 1164. The same year Andrey attacked the Volga Bolgars; he won a victory, but a son was killed in battle, to whose memory he ordered the construction of the Church of the Intercession on the Nerl in 1165.

Military activities
Andrey established for himself the right to receive tribute from the populations of the Northern Dvina lands.

In 1169 Andrey's troops sacked Kiev, devastating it as never before. After plundering the city, stealing much religious artwork, which included the Byzantine "Mother of God" icon. Andrey appointed his brother Gleb as prince of Kiev, in an attempt to unify his lands with Kiev.

Following his brother's death in 1171, Andrey became embroiled in a two-year war to maintain control over Kiev, which ended in his defeat at the Siege of Vyshgorod.

Death
After the 1169 capture of Kiev, the Yurievichi clan headed by Andrey temporarily dominated Kievan Rus' until his brother Gleb died in 1171, causing yet another succession crisis. When the Rostislavichi of Smolensk and Iziaslavichi of Volhynia jointly secured the throne of Kiev, Andrey assembled another coalition and marched on Vyshhorod in 1173, where the Yurievichi–Olgovichi forces of Suzdalia and Chernigov were utterly defeated. This defeat, the expansion of his princely authority, and his conflicts with the upper nobility, the boyars, gave rise to a conspiracy that resulted in Bogolyubsky's death on the night of 28–29 June 1174, when twenty of them burst into his chambers and slew him in his bed.

According to the story of Andrey Bogolyubsky's death as recorded in the Kievan Chronicle of the Hypatian Codex (Ipatiev), and the Radziwiłł Chronicle, his "right hand" was cut off by an assailant called "Peter" (Петръ):
 * Kievan Chronicle sub anno 6683 (1175 [sic]): Петръ же ѿтѧ ему руку десную. кнѧзь же вьзрѣвъ. на н҃бо. и реч̑ Гс̑и в руцѣ твои предаю тобѣ дх҃ъ мои. и тако оуспе оубьенъ же быс̑ в суботу на нощь.
 * Radziwiłł Chronicle sub anno 6683 (1175 [sic]): Петръ ему же от(ъ)тя руку десную. И убьенъ ж(е) быс(ть) в суб(оту) на ноч(ь).

However, the Radziwiłł Chronicle's adjoining miniature depicts his assailants cutting off his left arm. Moreover, when Dmitry Gerasimovich Rokhlin examined the exhumed body of Andrey Bogolyubsky in 1965, he "found a lot of cut marks on the left humerus and forearm bones". A 2009 special historical study by Russian historian A.V. Artcikhovsky (2009) would later confirm Rokhlin's observations.

Descendants
With his wife, Andrey Bogolyubsky had one son, Yury Bogolyubsky, who became the husband of Queen Tamar of Georgia.

Legacy

 * In the Suzdalian Chronicle, columns 367–369 contain the Short eulogy to Andrey Bogolyubsky.
 * In the Kievan Chronicle, columns 580–595 contain the Long eulogy to Andrey Bogolyubsky, also known as the Tale About the Slaying of Andrej Bogoljubskij (Povĕst' ob ubienii Andreja [Bogoljubskogo]).
 * The ancient icon, Theotokos of Bogolyubovo, was painted in the 12th century at the request of Andrey Bogolyubsky.
 * Andrey had the castle, Bogolyubovo, built near Vladimir, and it would become his favorite residence
 * His victory over the Bulgars is remembered yearly during the Honey Feast of the Saviour.

Literature

 * Paszkiewicz. H. (1954). The Origin of Russia. Chicago: The University of Chicago Press.
 * Review:
 * Review:
 * Reprinted in Pelenski, The Contest for the Legacy of Kievan Rus'.
 * Review:
 * Review:
 * Reprinted in Pelenski, The Contest for the Legacy of Kievan Rus'.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Andrey Bogolyubsky


text:
Hinduism in Russia

Hinduism has been spread in Russia primarily due to the work of scholars from the religious organization International Society for Krishna Consciousness (ISKCON) and by itinerant Swamis from India and small communities of Indian immigrants. While ISKCON appears to have a relatively strong following in Russia, the other organizations in the list have a marginal presence in this country. There is an active Tantra Sangha operating in Russia. According to the 2012 official census, there are 140,010 Hindus in Russia, which accounts for 0.1% of the population of Russia.

History
The history of Hinduism in Russia dates back to at least the 16th century. When Astrakhan was conquered in 1556, the small Indian community became part of the Moscow state.

In the early eighteenth century, the first Russian emperor, Peter the Great, met the head of the Astrakhan Hindus and, at their request, asked the Russian Senate to issue a law protecting Hindu beliefs. This was the first law in Russia that protected a foreign creed.

In the late eighteenth century, Russian traveller Pallas noted the presence of hundreds of Multani Vaiṣṇava Hindu merchant families at the mouth of the Volga river.

In 1971 A.C. Bhaktivedanta Swami Prabhupada, the founder of the International Society for Krishna Consciousness (ISKCON), introduced it to Russia. In 1988, ISKCON was first registered as a religion. Later, it was re-registered in 1998. In the same year, there were 120 Krishna communities in Russia.

Vaishnavism
As of December 2005, the Federal Registration Service recorded 79 Hindu groups with a particular orientation on Krishnaism. These are the International Society for Krishna Consciousness, ISKCON Revival Movement, Science of Identity Foundation, Sri Chaitanya Saraswat Math, Sri Chaitanya Gaudiya Math, Sri Krishna Chaitanya Mission, Sri Gopinatha Gaudiya Math, International Pure Bhakti Yoga Society, among others.

Shaivism
The followers of Shaivism in Russia are the Naths, Lingayats (Veerashaiva), and Tantra Sangha.

Hindu reform movements
Hindu reform movements which have presence in Russia are the Brahma Kumaris, Ramakrishna Mission, Arya Samaj, Sri Aurobindo Ashram, International Sivananda Yoga Vedanta Centres, Ananda Marga, Ananda Sangha, Self-Realization Fellowship, Sri Ramana Ashram, Sahaja Yoga, Sri Chinmoy Centre, Sanatan Sanstha, Sathya Sai Baba movement, Science of Identity Foundation, Shri Prakash Dham, the organizations associated with Maharishi Mahesh Yogi and Haidakhan Babaji (Haidakhandi Samaj), and others. Brahma Kumaris have 20 centres, Ramakrishna Mission has one centre, Ananda Marga has a centre in Barnaul, Tantra Sangha has one registered branch in Moscow and another in Nizhniy Novgorod was officially recognized in 1993.

Demography

According to the 2012 official census, Hinduism is practised by 140,000 people, or 0.1% of the total population. It constitutes 12% of the population in the Altai Republic, 5% in Samara Oblast, 4% in Khakassia, Kalmykia, Bryansk Oblast, Kamchatka, Kurgan Oblast, Tyumen Oblast and Chelyabinsk Oblast, 3% in Sverdlovsk Oblast, 2% to 3% in Yamalia, Krasnodar Krai, Stavropol Krai, Rostov Oblast and Sakhalin Oblast, and 0.1% to 0.2% in other federal subjects.

In 2006, the Russian capital Moscow had an estimated 10,000 Hare Krishna devotees and at least 5,000 Indians, Sri Lankans, Nepalese, and Mauritians following Hindu denominations.

The number of ISKCON followers in Russia is disputed. According to Sanjeet Jha of the Association of Indians of Russia, Russia's Krishna devotee population is estimated to be as high as 250,000, while Filatov of the Institute of Oriental Studies estimates Russia's Krishna population to be 15,000. According to Bhakti Vijnana Goswami, a Russian Iskcon guru, there were 50,000 active Hare Krishna devotees in Russia in 2011.

title: Hinduism in Russia


text:
Quentin Skinner

Quentin Robert Duthie Skinner (born 26 November 1940) is a British intellectual historian. He is regarded as one of the founders of the Cambridge School of the history of political thought. He has won numerous prizes for his work, including the Wolfson History Prize in 1979 and the Balzan Prize in 2006. Between 1996 and 2008 he was Regius Professor of History at the University of Cambridge. He is the Emeritus Professor of the Humanities and Co-director of The Centre for the Study of the History of Political Thought at Queen Mary University of London.

Biography
Quentin Skinner was born on 26 November 1940, the second son of Alexander Skinner (died 1979) and Winifred Skinner, née Duthie (died 1982). He was educated at Bedford School from the age of seven. Like his elder brother, he won an entrance scholarship to Gonville and Caius College, Cambridge, from where he graduated with a double-starred first in history in 1962. Skinner was elected to a fellowship of his college on his examination results, but moved later in 1962 to a teaching fellowship at Christ's College, Cambridge, where he remained until moving to the University of London in 2008. He is now an Honorary Fellow of both Christ's College and Gonville and Caius College.

Skinner was appointed to a lectureship in the Faculty of History at the University of Cambridge in 1965. He spent a sabbatical year at the Institute for Advanced Study in Princeton in 1974–1975, where he was invited to stay, and where he remained until 1979, when he returned to Cambridge as Professor of Political Science. He was appointed to the post of Regius Professor of History in 1996, and in 1999 as pro-vice-chancellor of the university.

In 1979 he married Susan James, Professor of Philosophy at Birkbeck College London. They have a daughter and a son, and four grandchildren. He was previously married to Patricia Law Skinner, who was later married to the philosopher Bernard Williams.

Skinner has held a number of visiting appointments. He has been Visiting Fellow at the Research School of Social Science at the Australian National University (1970, 1994, 2006); Visiting Professor at Washington University in St. Louis (1982); Directeur d’Etudes Associé at the Ecole des Hautes Etudes (1987); Professeur Associé at Université Paris X (1991); Visiting Professor at the University of Leuven (1992); Visiting Professor at Northwestern University (1995, 2011); Professeur invité at the Collège de France (1997); Fellow at the Wissenschaftskolleg zu Berlin (2003–04); Visiting Scholar at the Center for European Studies at Harvard University (2008); Laurence Rockefeller Visiting Professor at Princeton University (2013–14); Spinoza Visiting Professor at the University of Amsterdam (2014); Visiting Professor in the Global Fellowship programme at Peking University, Beijing (2017); and Visiting Professor at the University of Chicago (2017).

Skinner has delivered a number of named lecture series, including the Gauss Seminars at Princeton (1980), The Carlyle Lectures at Oxford (1980), The Messenger Lectures at Cornell (1983), The Tanner Lectures at Harvard (1984), the Ford Lectures at Oxford (2003), the Clarendon Lectures at Oxford (2011), the Clark Lectures at Cambridge (2012) and the Academia Sinica Lectures in Taiwan (2013).

Skinner has been a Fellow of the British Academy since 1981, and is also a foreign member of a number of national academies, including the American Academy of Arts and Sciences (1986), the Academia Europaea (1989), the American Philosophical Society (1997), the Royal Irish Academy (1999), the Accademia Nazionale dei Lincei (2007), the Österreichische Academie der Wissenschaften (2009), and the Royal Danish Academy (2015). He has been the recipient of Honorary Degrees from the University of Aberdeen, University of Athens, University of Chicago, University of Copenhagen, University of East Anglia, Harvard University, University of Helsinki, Katholieke Universiteit Leuven, University of Kent, University of Oslo, University of Oxford, Adolfo Ibáñez University (Santiago), University of St Andrews and Uppsala University. He was awarded the Wolfson History Prize in 1979, the Sir Isaiah Berlin Prize of the British Political Studies Association in 2006, the Benjamin Lippincott Award (2001), the David Easton Award (2007) of the American Political Science Association, the Bielefeld Science Award (2008) and a Balzan Prize (2006). From 2009 until 2020, he was a member of the Balzan Prize Committee.

Methodology
Skinner is regarded as one of the founders of the 'Cambridge School' of the history of political thought, best known for its attention to what J. G. A. Pocock has described as the 'languages' in which moral and political philosophy has been written. Skinner's contribution has been to articulate a theory of interpretation in which leading texts in the history of political theory are treated essentially as interventions in on-going political debates, and in which the main focus is on what individual writers may be said to have been doing in what they wrote.

This emphasis on political writing as a form of action derives from developments in ordinary language philosophy made by Ludwig Wittgenstein and J. L. Austin. Wittgenstein's insight was (in Skinner’s words) "that we should stop asking about the 'meanings' of words and focus instead on the various functions they are capable of performing in different language games". Skinner takes Austin to have extended Wittgenstein's argument in isolating the concept of a speech act, which is described by Skinner as the notion that "whenever we use language for purposes of communication, we are always doing something as well as saying something". According to Skinner, that means that any analysis is incomplete if it restricts itself to studying what a past thinker said on a given issue. Historians must also recover what a thinker hoped to achieve in saying it. Skinner consequently proposes a form of linguistic contextualization that involves situating a text in relation to other texts and discourses. In that perspective, the text is a response to other thinkers, texts or cultural discourses. Skinner believes that ideas, arguments and texts should be placed in their original context. One consequence of this view is an emphasis on the necessity of studying less well-known political writers as a means of shedding light on the contemporary debates these classic texts contributed to. In that way, it becomes possible to decipher the original purpose of a text. To Skinner, texts are then seen as weapons or tools that can, for example, be used to support, discredit, or legitimize specific social and political arrangements. In its earlier versions this added up to a critique of the approach of an older generation, and particularly of Leo Strauss and his followers.

Empirical focus
Skinner's historical work has mainly focused on political thinking in early-modern Europe. He has written a book on Niccolò Machiavelli, three books on Thomas Hobbes, and his Foundations of Modern Political Thought covers the whole period. He has specifically been concerned with the emergence of modern theories about the nature of the state, and with debates about the nature of political liberty.

Miscellany
When Skinner was interviewed by Alan Macfarlane, as part of his series of online conversations with academics, Skinner admitted that he had been a member of the Cambridge Apostles, a secret debating society in Cambridge University. He also revealed that Amartya Sen was a member at the same time. Sen mentioned their membership of the Apostles in his memoir Home in the World. He commented that they had both been "outed" in a book published about the Apostles some time before.

On 6 October 1995, Skinner's Foundations of Modern Political Thought was included in the list published by The Times Literary Supplement of 'The 100 Most Influential Books since World War II'.

On 14 May 2009, Times Higher Education, in an article about Skinner's move from Cambridge to the University of London, spoke of Skinner's republicanism, reporting that this led him to refuse a knighthood he was offered when he became Regius Professor of History at Cambridge.

The Balzan-Skinner Lectureship, renamed the "Quentin Skinner Fellowship in Intellectual History since 1500", was established in 2009 at the University of Cambridge. The Quentin Skinner fellow holds a visiting fellowship at the Centre for Research in the Arts, Social Sciences and Humanities for one term of the academic year, which culminates in the Quentin Skinner Lecture and an associated symposium.

Books
1. The Foundations of Modern Political Thought: Volume I: The Renaissance, Cambridge University Press, 1978. ISBN 978-0-521-29337-2 (Translated into Arabic, Chinese, French, Greek, Italian, Korean, Japanese, Persian, Portuguese, Russian, Spanish, Turkish.)

2. The Foundations of Modern Political Thought: Volume II: The Age of Reformation, Cambridge University Press, 1978. ISBN 978-0-521-29435-5 (Translated into Arabic, Chinese, French, Greek, Italian, Japanese, Persian, Portuguese, Russian, Spanish.)

3(a). Machiavelli, Oxford University Press, 1981.

3(b). Machiavelli: A Very Short Introduction [A revised version of 3(a)], Oxford University Press, 2000. ISBN 978-0-19-285407-0 (Translated into Albanian, Arabic, Chinese, Czech, French, German, Greek, Hebrew, Hungarian, Indonesian, Italian, Japanese, Korean, Kurdish, Malay, Polish, Persian, Portuguese, Romanian, Russian, Spanish, Swedish, Turkish.)

3(c). Machiavelli: A Very Short Introduction [a new and updated edition of 3(b)], Oxford University Press, 2019. ISBN 978-0-19-883757-2

4. Reason and Rhetoric in the Philosophy of Hobbes, Cambridge University Press, 1996. ISBN 978-0-521-59645-9 (Translated into Chinese, Italian, Portuguese.)

5. Liberty before Liberalism, Cambridge University Press, 1998. ISBN 978-1-107-68953-4 (Translated into Chinese, French, Greek, Italian, Korean, Persian, Polish, Portuguese, Russian, Spanish.)

6. Visions of Politics: Volume I: Regarding Method, Cambridge University Press, 2002. ISBN 978-0-521-58926-0 (Translated into Chinese, French, Italian, Korean, Persian, Polish, Portuguese, Spanish.)

7. Visions of Politics: Volume II: Renaissance Virtues (with 12 colour plates), Cambridge University Press, 2002. ISBN 978-0-521-58926-0 (Translated into Italian.)

8. Visions of Politics: Volume III: Hobbes and Civil Science, Cambridge University Press, 2002. ISBN 978-0-521-89060-1

9. L’artiste en philosophie politique (with 8 colour plates), Editions de Seuil, Paris, 2003. ISBN 978-2-912107-15-2

10. Hobbes and Republican Liberty (with 19 illustrations), Cambridge University Press, 2008. ISBN 978-2-912107-15-2 (Translated into Chinese, French, German, Portuguese, Spanish.)

11. La verité et l’historien, ed. Christopher Hamel, Editions EHESS, Paris, 2011. ISBN 978-2-7132-2368-6

12. Die drei Körper des Staates, Wallstein, Göttingen, 2012. ISBN 978-3-8353-1157-2

13. Forensic Shakespeare, Oxford University Press, 2014. ISBN 978-0-19-955824-7

14. From Humanism to Hobbes: Studies in Rhetoric and Politics (with 45 illustrations), Cambridge University Press, 2018. ISBN 978-1-107-56936-2

Articles
● 2018: Beaumont, Tim. "A Perennial Illusion? Wittgenstein, Quentin Skinner's Contextualism and the Possibility of Refuting Past Philosophers". Philosophical Investigations. 41 (3): 304–28. doi:doi.org/10.1111/phin.12196 https://onlinelibrary.wiley.com/doi/abs/10.1111/phin.12196

Note: the following are two special issues of Francophone journals containing a number of articles (written in French) concerning the life and work of Quentin Skinner, the full contents of each issue can be found in the subsequent links.

 * 2022: ‘Quentin Skinner: Interpréter et expliquer’: Analogia: revue annuelle de philosophie, ed. Florian Laguens, numero 2, Paris. ISBN 979-10-93043-41-8 "Institut de Philosophie Comparée Publications: Introduction by Florian Laguens"
 * 2024: ‘Autour de Quentin Skinner’, Raisons politiques 93, Paris. ISBN 978-2-7246-4227-8 "Presses de Sciences Po: Raisons politiques 93, février 2024"

title: Quentin Skinner


text:
Crevice weaver

Crevice weaver spiders (Filistatidae) comprise cribellate spiders with features that have been regarded as "primitive" for araneomorph spiders. They are weavers of funnel or tube webs. The family contains 18 genera and more than 120 described species worldwide.

One of the most abundant members of this family in the Americas is the southern house spider (Kukulcania hibernalis). Named after the fierce Meso-American god Kukulkan, the females are large (up to nearly 20 mm) dark-colored spiders and males are light brown, smaller (about 10 mm), but more long-legged and with palps that are held together in front of their carapaces like the horn of a unicorn. The males also have a darker streak on the center of the dorsal carapace that causes them to be often mistaken for brown recluse spiders. The tiny members of the genus Filistatinella are like miniature versions of Kukulcania. The nominate genus Filistata is Afro-Eurasian in distribution. In many older books the species from the Americas now placed in the genus Kukulcania are placed in Filistata.

A striking visual characteristic of the family, beside dimorphism, is the unusual upward bend encountered near the femur of the first pair of legs. While resembling hydraulic muscle mechanisms akin to arthropods, this modification actually allows the spider to retain the prey directly from the crevice it occupies. Also, if the larger prey ever tries to pull it from the crevice, the spider can use these legs to "grab" to the side walls and hence make it difficult. Many Kukulcania species also use them to dig holes in the soft ground at a 25- to 30-degree angle.

Taxonomy
The family Filistatidae was created in 1867 by Anton Ausserer. It was based on the species he called Filistata bicolor (now Filistata insidiatrix), a Mediterranean species also found in southern Austria.

Phylogeny
On the basis of the features of the male and female genitalia, the family was placed in the Haplogynae, usually as the sister taxon of the remaining members of the group. However, unlike the other haplogynes, Filistatidae are cribellate and do not show a decrease in the number of segments of the anterior lateral spinnerets. They have other features which have been regarded as "primitive": an M-shaped intestine, only leg IV moving while combing silk, and posterior book lung leaves being present in early juveniles. A 2013 study based on molecular evidence placed the family as sister to a clade consisting of Hypochilidae and the remaining haplogynes. The precise phylogenetic position of the family was described in 2014 as "one of the most enigmatic problems in spider phylogeny".

A 2015 study, based on genomic data, places Filistatidae with Hypochilidae in a clade outside most of the families previously placed in Haplogynae:

This placement suggests that features that were thought to be "primitive" to araneomorph spiders as a whole (such as an M-shaped midgut) could actually be novel derived features (synapomorphies) of the Hypochilidae-Filistatidae clade.

Genera
, the World Spider Catalog accepts the following genera:

 * Afrofilistata Benoit, 1968 — Sudan
 * Andoharano Lehtinen, 1967 — Namibia, Madagascar
 * Antilloides Brescovit, Sánchez-Ruiz & Alayón, 2016 — Mexico
 * Filistata Latreille, 1810 — Australia, Asia
 * Filistatinella Gertsch & Ivie, 1936 — Mexico, United States
 * Filistatoides F. O. Pickard-Cambridge, 1899 — Guatemala, Chile, Cuba
 * Kukulcania Lehtinen, 1967 — North America, Central America, Chile
 * Labahitha Zonstein, Marusik & Magalhaes, 2017 — Malaysia
 * Lihuelistata Ramírez & Grismado, 1997 — Argentina
 * Microfilistata Zonstein, 1990 — Iran, Turkmenistan, Tajikistan
 * Misionella Ramírez & Grismado, 1997 — Brazil, Argentina
 * Pholcoides Roewer, 1960 — Afghanistan, Tajikistan, India
 * Pikelinia Mello-Leitão, 1946 — South America
 * Pritha Lehtinen, 1967 — Asia, Oceania, Africa, France
 * Sahastata Benoit, 1968 — Asia, Eritrea
 * Tricalamus Wang, 1987 — China, Japan, Afghanistan
 * Wandella Gray, 1994 — Australia
 * Yardiella Gray, 1994 — Australia
 * Zaitunia Lehtinen, 1967 — Asia, Greece

title: Crevice weaver


text:
Talk:Sultan Murad

Untitled
We have this already under Murad II. It shoudl be merged. Danny 01:09, 18 Jul 2004 (UTC)

title: Talk:Sultan Murad


text:
Talk:KCAU TV Tower

Where is this tower? Mike H 01:14, Jul 18, 2004 (UTC)

title: Talk:KCAU TV Tower


text: Category:Royal Jordanian Air Force

title: Category:Royal Jordanian Air Force


text:
Category:Neuroscientists

People who study or are related to the study of neuroscience.

title: Category:Neuroscientists


text: Category:Royal Moroccan Air Force

title: Category:Royal Moroccan Air Force


text:
Tender Is the Night

Tender Is the Night is the fourth and final novel completed by American writer F. Scott Fitzgerald. Set in French Riviera during the twilight of the Jazz Age, the 1934 novel chronicles the rise and fall of Dick Diver, a promising young psychiatrist, and his wife, Nicole, who is one of his patients. The story mirrors events in the lives of the author and his wife Zelda Fitzgerald as Dick starts his descent into alcoholism and Nicole struggles with mental illness.

Fitzgerald began the novel in 1925 after the publication of his third novel The Great Gatsby. During the protracted writing process, the mental health of his wife rapidly deteriorated, and she required extended hospitalization due to her suicidal and homicidal tendencies. After her hospitalization in Baltimore, Maryland, the author rented the La Paix estate in the suburb of Towson to be close to his wife, and he continued working on the manuscript.

While working on the book, Fitzgerald was beset with financial difficulties and drank heavily. He kept afloat by borrowing money from both his editor Max Perkins and his agent Harold Ober, as well as writing short stories for commercial magazines. Fitzgerald completed the work in fall 1933, and Scribner's Magazine serialized the novel in four installments between January and April 1934 before its publication on April 12, 1934. Although artist Edward Shenton illustrated the serialization, he did not design the book's jacket. The jacket was by an unknown artist, and Fitzgerald disliked it. The title is taken from the poem "Ode to a Nightingale" by John Keats.

Two versions of the novel are in print. The first version, published in 1934, uses flashbacks; the second, revised version, prepared by Fitzgerald's friend and critic Malcolm Cowley on the basis of notes for a revision left by Fitzgerald, is ordered chronologically and was first published posthumously in 1948. Critics have suggested that Cowley's revision was undertaken due to negative reviews of the temporal structure of the first version of the book.

Fitzgerald considered the novel to be his masterwork. Although it received a tepid response upon release, it has grown in acclaim over the years and is now regarded as among Fitzgerald's best works. In 1998, the Modern Library ranked the novel 28th on its list of the 100 best English-language novels of the 20th century.

Plot summary
Dick and Nicole Diver are a glamorous couple who rent a villa in the South of France and surround themselves with a coterie of American expatriates. Rosemary Hoyt, a 17-year-old actress, and her mother are staying at a nearby resort. Rosemary becomes infatuated with Dick and becomes close to Nicole.

Rosemary senses something is wrong with the couple, and her suspicions are confirmed when another guest at a party, Violet McKisco, reports witnessing Nicole's nervous breakdown in a bathroom. Tommy Barban, another guest, comes to the defense of Nicole and insists that Violet is lying. Angered by this accusation, Violet's husband Albert duels Barban on the beach, but both men miss their shots. Following these events, Dick, Nicole, Rosemary, and others depart the French Riviera.

Soon after, Rosemary is now a constant companion of both Dick and Nicole in Paris. She attempts to seduce Dick in her hotel room, but he rebuffs her advances, although he admits that he loves her. Much later, a black man named Jules Peterson is found murdered in Rosemary's bed at the hotel, a potential scandal which could destroy Rosemary's career. Dick moves the blood-soaked body out of the room to cover up any implied sexual relationship between Rosemary and Peterson.

A flashback occurs in the narrative. In Spring 1917, Dick Diver—a promising young doctor—visits psychopathologist Franz Gregorovius in Zürich, Switzerland. While visiting Franz, he meets a patient named Nicole Warren, a wealthy young woman whose sexual abuse by her father has led to mental neuroses. Over a period of time they exchange letters. With the permission of Franz who believes that Dick's friendship benefits Nicole's well-being, they start seeing each other. As Nicole's treatment progresses, she becomes infatuated with Dick who, in turn, develops Florence Nightingale syndrome. He determines to marry Nicole in order to provide her with lasting emotional stability.

Dick is offered a partnership in a Swiss psychiatric clinic by Franz, and Nicole uses her finances to pay for the enterprise. After his father's death, Dick travels to America for the burial and then journeys to Rome in hopes of seeing Rosemary. They start a brief affair which ends abruptly and painfully. A heartbroken Dick is involved in an altercation with the Italian police and is physically beaten. Nicole's sister helps him to get out of jail. After this public humiliation, his incipient alcoholism increases. When his alcoholism threatens his medical practice, Dick's ownership share of the clinic is purchased by American investors following Franz's suggestion.

Dick and Nicole's marriage disintegrates as he pines for Rosemary who has become a successful Hollywood star. Nicole distances herself from Dick as his self-confidence and friendliness turn into sarcasm and rudeness towards everyone. His constant unhappiness over what he could have been fuels his alcoholism, and Dick becomes embarrassing in social and familial situations. A lonely Nicole enters into an affair with Tommy Barban. She later divorces Dick and marries her lover.

Major characters

 * Richard "Dick" Diver – a promising young psychiatrist and Yale alumnus who marries his patient Nicole Diver and becomes an alcoholic.
 * Nicole Diver (née Warren) – an affluent mental patient who was the victim of incest and who marries Dick Diver. Based on Zelda Fitzgerald.
 * Rosemary Hoyt – an eighteen-year-old Hollywood actress who falls in love with Dick Diver. Based on teenage starlet Lois Moran.
 * Tommy Barban – a Franco-American soldier-of-fortune with whom Nicole Diver has an affair. Based on French aviator Edouard Jozan, and on Italian-American pianist composer Mario Braggiotti.
 * Franz Gregorovious – a Swiss psychopathologist at Dohmler's clinic who introduces a young Dick Diver to Nicole Warren, his patient.
 * Beth "Baby" Warren – an unmarried spinster who is Nicole's older sibling and who disapproves of her marriage to Dick Diver.
 * Abe North – an alcoholic composer who is later murdered in a New York speakeasy. Based on Ring Lardner and Charles MacArthur.
 * Mary North – the spirited wife of Abe North who divorces him, remarries, and becomes the wealthy Countess of Minghetti.
 * Albert McKisco – an American novelist who wins a duel against Tommy Barban. Based on novelist Robert McAlmon.
 * Violet McKisco – the gossipy spouse of Albert McKisco who discovers Nicole's insanity and attempts to malign her reputation.
 * Jules Peterson – a black man from Scandinavia who helps Abe North and is later found dead in Rosemary Hoyt's hotel suite.

Sojourn in Europe
While abroad in Europe, F. Scott Fitzgerald began writing his fourth novel almost three weeks after the publication of The Great Gatsby in April 1925. He planned to tell the story of Francis Melarkey, a young Hollywood technician visiting the French Riviera with his domineering mother. Francis falls in with a circle of charming American expatriates, emotionally disintegrates, and kills his mother. Fitzgerald's tentative titles for the novel were "World's Fair," "Our Type" and "The Boy Who Killed His Mother." The characters of the charming American expatriates were based on Fitzgerald's acquaintances Gerald and Sara Murphy and were named Seth and Dinah Piper. Francis was intended to fall in love with Dinah, an event that would precipitate his disintegration.

Fitzgerald wrote five drafts of this earlier version of the novel in 1925 and 1926, but he was unable to finish it. Nearly all of what he wrote made it into the finished work in altered form. Francis's arrival on the Riviera with his mother, and his introduction to the world of the Pipers, was transposed into Rosemary Hoyt's arrival with her mother, and her introduction to the world of Dick and Nicole Diver. Characters created in this early version survived into the final novel, particularly Abe and Mary North (originally Grant) and the McKiscos.

Several incidents such as Rosemary's arrival and early scenes on the beach, her visit to the Riviera movie studio, and the dinner party at the Divers' villa all appeared in this original version, but with Francis in the role of the wide-eyed outsider that would later be filled by Rosemary. Also, the sequence in which a drunken Dick is beaten by police in Rome was written in this first version as well and was based on a real incident that happened to Fitzgerald in Rome in 1924.

Return to America
After a certain point, Fitzgerald became stymied with the novel. He, Zelda, and their daughter Scottie returned to the United States in December 1926 after several years in Europe. Film producer John W. Considine Jr. invited Fitzgerald to Hollywood during its golden age to write a flapper comedy for United Artists. He agreed and moved into a studio-owned bungalow with Zelda in January 1927. In Hollywood, the Fitzgeralds attended parties where they danced the black bottom and mingled with film stars.

While attending a lavish party at the Pickfair estate, Fitzgerald met 17-year-old Lois Moran, a starlet who had gained widespread fame for her role in Stella Dallas (1925). Desperate for intellectual conversation, Moran and Fitzgerald discussed literature and philosophy for hours while sitting on a staircase. Fitzgerald was 31 years old and past his prime, but the smitten Moran regarded him as a sophisticated, handsome, and gifted writer. Consequently, she pursued a relationship with him. The starlet became a muse for the author, and he wrote her into a short story called "Magnetism", in which a young Hollywood film starlet causes a married writer to waver in his sexual devotion to his wife. Fitzgerald later rewrote Rosemary Hoyt—one of the central characters in Tender is the Night—to mirror Moran.

Jealous of Fitzgerald's relationship with Moran, an irate Zelda set fire to her expensive clothing in a bathtub as a self-destructive act. She disparaged the teenage Moran as "a breakfast food that many men identified with whatever they missed from life." Fitzgerald's relations with Moran further exacerbated the Fitzgeralds' marital difficulties and, after merely two months in Hollywood, the unhappy couple departed for Delaware in March 1927.

Fitzgerald supported himself and his family in the late 1920s with his lucrative short-story output for slick magazines such as the Saturday Evening Post, but he was haunted by his inability to progress on the novel. Around 1929 he tried a new angle on the material, starting over with a shipboard story about a Hollywood director Lew Kelly and his wife Nicole as well as a young actress named Rosemary. But Fitzgerald only completed two chapters of this version.

Zelda's mental illness
By Spring 1929, the Fitzgeralds had returned to Europe when Zelda's mental health deteriorated. During an automobile trip to Paris along the mountainous roads of the Grande Corniche, Zelda seized the car's steering wheel and tried to kill herself, her husband F. Scott Fitzgerald, and their 9-year-old daughter Scottie by driving over a cliff. After this homicidal incident, Zelda sought psychiatric treatment, and doctors diagnosed her with schizophrenia in June 1930. Zelda's biographer, Nancy Milford, quotes Dr. Oscar Forel's contemporary psychiatric diagnosis: "'The more I saw Zelda, the more I thought at the time [that] she is neither [suffering from] a pure neurosis nor a real psychosis—I considered her a constitutional, emotionally unbalanced psychopath—she may improve, [but] never completely recover.'"

Seeking a cure for her mental illness, the couple traveled to Switzerland where Zelda underwent further treatment at a clinic. Zelda's ingravescent mental illness and the death of Fitzgerald's father in 1931 dispirited the author. Devastated by these events, an alcoholic Fitzgerald settled in suburban Baltimore where he rented the La Paix estate from architect Bayard Turnbull. He decided the novel's final plot would involve a young man of great potential who marries a mentally-ill woman and sinks into despair and alcoholism when their doomed marriage fails.

Final draft and publication
Fitzgerald wrote the final version of Tender Is the Night in 1932 and 1933. He salvaged almost everything he had written for the earlier Melarkey draft of the novel, as well as borrowed ideas and phrases from many short stories he had written in the years since completing The Great Gatsby. Ultimately, he poured everything he had into Tender—his feelings regarding his wasted talent and self-perceived professional failure; his animosity towards his parents; his marriage to Zelda and her mental illness; his infatuation with actress Lois Moran, and Zelda's affair with the French aviator Edouard Jozan.

Fitzgerald finished the work in the autumn of 1933, and it was serialized in Scribner's Magazine over four parts from January to April 1934, leading up to its release on April 12, 1934. Although Edward Shenton provided illustrations for the serialization, he wasn't responsible for the book's jacket design, which was done by an unknown artist and not favored by Fitzgerald. The title of the novel was inspired by John Keats' poem "Ode to a Nightingale".

Critical reception
Fitzgerald deemed the novel to be his masterwork and believed it would eclipse the acclaim of his previous works. It was instead met with lukewarm sales and mixed reviews. One book review in The New York Times by critic J. Donald Adams was particularly harsh:

"'Bad news is best blurted out at once: Tender Is the Night is a disappointment. Though it displays Mr. Fitzgerald’s most engaging qualities, it makes his weaknesses appear ineradicable, for they are present in equal measure and in undiminished form.... His new book is clever and brilliantly surfaced, but it is not the work of a wise and mature novelist.'"

In contrast to the negative review in The New York Times, critic Burke Van Allen hailed the novel as a masterpiece in a April 1934 review in The Brooklyn Daily Eagle:

"'Besides Mr. Fitzgerald, no American novelist... has written four novels without a bad one, with a constantly growing mastery of his equipment, and a regularly increasing sensitivity to the esthetic values in life. Scott Fitzgerald grows, and his literature was born imposing... The variation of mood with which he has four times accomplished... is extraordinary. The mood in This Side of Paradise was vindictive and rebellious; in The Beautiful and Damned sour and satirical; in Gatsby straightforward and tragic, inevitable, and in Tender Is the Night it is stained with a civilized and wounding brutality. It is necessary to say that I, the reviewer, have never used this severe word in print before: masterpiece.'"

Three months after its publication, Tender Is the Night had sold only 12,000 copies compared to This Side of Paradise which sold over 50,000 copies. Despite a number of positive reviews, a consensus emerged that the novel's Jazz Age setting and subject matter were both outdated and uninteresting to readers. The unexpected failure of the novel puzzled Fitzgerald for the remainder of his life.

Various hypotheses have arisen as to why the novel did not receive a warmer reception upon release. Fitzgerald's friend, author Ernest Hemingway, opined that critics had initially only been interested in dissecting its weaknesses, rather than giving due credit to its merits. He argued that such overly harsh criticism stemmed from superficial readings of the material and Depression-era America's reaction to Fitzgerald's status as a symbol of Jazz Age excess. In his later years, Hemingway re-read the work and remarked that, in retrospect, "Tender Is the Night gets better and better".

Posthumous reevaluation
Following Fitzgerald's death in 1940, Tender Is the Night's critical reputation has steadily grown. Later critics have described it as "an exquisitely crafted piece of fiction" and "one of the greatest American novels". It is now widely regarded as among Fitzgerald's most accomplished works, with some agreeing with the author's assessment that it surpasses The Great Gatsby.

Several critics have interpreted the novel to be a feminist work and posited that the patriarchal attitudes of the reactionary 1930s underlay the critical dismissal. They have noted the parallels between Dick Diver and Jay Gatsby, with many regarding the novel and particularly Diver's character, as Fitzgerald's most emotionally and psychologically complex work.

Christian Messenger argues that Fitzgerald's book hinges on the sustaining sentimental fragments: "On an aesthetic level, Fitzgerald's working through of sentiment's broken premises and rhetoric in Tender heralds a triumph of modernism in his attempt to sustain his sentimental fragments and allegiances in new forms." He calls it "F. Scott Fitzgerald's richest novel, replete with vivid characters, gorgeous prose, and shocking scenes," and calls attention to Slavoj Žižek's use of the book to illustrate the nonlinear nature of experience.

Legacy and influence
In 1998, the Modern Library included the novel at #28 on its list of the 100 best English-language novels of the 20th century. Radcliffe later included it at #62 in its rival list. NPR included it at #69 on its 2009 list titled 100 Years, 100 Novels. In 2012 it was listed as one of the 1001 Books You Must Read Before You Die.

Adaptations
In 1955, an hour long adaptation was broadcast live by CBS on the General Electric sponsored show "Front Row Center", with Mercedes McCambridge as Nicole Diver. Dick Diver was played by James Daly. The telefilm was written by Whitfield Cook and directed and produced by McCambridge’s then-husband, Fletcher Markle. It featured original music by eminent composer David Raksin. New York Times reviewer John P. Shanley panned it as "an inept conception" and "an unforgivable treatment of a gifted author's work."

In 1962, a film adaptation was released with Jason Robards as Dick Diver and Jennifer Jones as Nicole Diver. The song "Tender Is the Night" from the movie soundtrack was nominated for the 1962 Academy Awards for Best Song.

Two decades later, in 1985, a television mini-series of the book was co-produced by the BBC, 20th Century Fox Television, and Showtime Entertainment. The mini-series featured Peter Strauss as Dick Diver, Mary Steenburgen as Nicole Diver, and Sean Young as Rosemary Hoyt.

In 1995, a stage adaptation by Simon Levy, with permission of the Fitzgerald Estate, was produced at The Fountain Theatre, Los Angeles. It won the PEN Literary Award in Drama and several other awards.

Boris Eifman's 2015 ballet Up and Down is based loosely on the novel.

title: Tender Is the Night


text:
Talk:Continuity correction

It's darn useful that this article brought my attention to this issue, as I have a binomial implementation which appears to delegate to Poisson without the correction.

Aside from the lack of references, an expert might add a sentence or two motivating why the continuity correction is required. MaxEnt 20:13, 30 August 2007 (UTC)

 * Looking into this a little deeper.
 * http://cns2.uni.edu/~campbell/stat/prob9.html
 * http://mathworld.wolfram.com/ContinuityCorrection.html
 * It's not that I don't find the geometric argument compelling, it's that I don't find it obvious that the 'corrected' function dominates the uncorrected function (ie. that the CC normal curve is better approx. to the binomial than un-CC normal for all integers x); nor is it obvious there is anything wrong with the implied binomial mass distribution for un-CC; is it not that CC dominates non-CC everywhere except finitely many exceptions? Is that the point of this?  MaxEnt 23:34, 30 August 2007 (UTC)

I guess I thought it was obvious why the corrected version is better than the uncorrected normal. Maybe I'll add something explicit on this. But I don't understand what is meant by the following words:
 * nor is it obvious there is anything wrong with the implied binomial mass distribution for un-CC
 * nor is it obvious there is anything wrong with the implied binomial mass distribution for un-CC

What does that mean?? Michael Hardy 00:14, 31 August 2007 (UTC)

Continuity correction for x np
It seems there is a different CC depending on where the characteristic of interest x falls with respect to the Binomial mean. When x < np (is below the mean) the correction is to add .5 to x. When x > np  the correction is to subtract .5 from x. In either case this brings the z-score of interest closer to the mean. Then when testing, the area in the corresponding tail will be bigger. My textbook had the second one wrong in one of two places, finally figured its error was in its Summary of Formulas for Chapter 5, and correct under Correction for Continuity, Ch. 5.5. Nothing in another text, nor in the first 4 - 6 links of my search (including this, link 2), so I am placing it here. Hope you include it. Figured it out (which equation was the correct one and what it meant) partly by way of the example in the text. Biostatistics A Foundation for Analysis in the Health Sciences, 10th edition, c. 2013, Daniel, Wayne W. and Cross, Chad L., pub. John Wiley & Sons, Inc. — Preceding unsigned comment added by 69.211.51.26 (talk) 19:55, 2 February 2019 (UTC)

title: Talk:Continuity correction


text:
Active electronically scanned array

An active electronically scanned array (AESA) is a type of phased array antenna, which is a computer-controlled antenna array in which the beam of radio waves can be electronically steered to point in different directions without moving the antenna. In the AESA, each antenna element is connected to a small solid-state transmit/receive module (TRM) under the control of a computer, which performs the functions of a transmitter and/or receiver for the antenna. This contrasts with a passive electronically scanned array (PESA), in which all the antenna elements are connected to a single transmitter and/or receiver through phase shifters under the control of the computer. AESA's main use is in radar, and these are known as active phased array radar (APAR).

The AESA is a more advanced, sophisticated, second-generation of the original PESA phased array technology. PESAs can only emit a single beam of radio waves at a single frequency at a time. The PESA must utilize a Butler matrix if multiple beams are required. The AESA can radiate multiple beams of radio waves at multiple frequencies simultaneously. AESA radars can spread their signal emissions across a wider range of frequencies, which makes them more difficult to detect over background noise, allowing ships and aircraft to radiate powerful radar signals while still remaining stealthy, as well as being more resistant to jamming. Hybrids of AESA and PESA can also be found, consisting of subarrays that individually resemble PESAs, where each subarray has its own RF front end. Using a hybrid approach, the benefits of AESA (e.g., multiple independent beams) can be realized at a lower cost compared to pure AESA.

History
Bell Labs proposed replacing the Nike Zeus radars with a phased array system in 1960, and was given the go-ahead for development in June 1961. The result was the Zeus Multi-function Array Radar (ZMAR), an early example of an active electronically steered array radar system. ZMAR became MAR when the Zeus program ended in favor of the Nike-X system in 1963. The MAR (Multi-function Array Radar) was made of a large number of small antennas, each one connected to a separate computer-controlled transmitter or receiver. Using a variety of beamforming and signal processing steps, a single MAR was able to perform long-distance detection, track generation, discrimination of warheads from decoys, and tracking of the outbound interceptor missiles.

MAR allowed the entire battle over a wide space to be controlled from a single site. Each MAR, and its associated battle center, would process tracks for hundreds of targets. The system would then select the most appropriate battery for each one, and hand off particular targets for them to attack. One battery would normally be associated with the MAR, while others would be distributed around it. Remote batteries were equipped with a much simpler radar whose primary purpose was to track the outgoing Sprint missiles before they became visible to the potentially distant MAR. These smaller Missile Site Radars (MSR) were passively scanned, forming only a single beam instead of the MAR's multiple beams.

While MAR was ultimately successful, the cost of the system was enormous. When the ABM problem became so complex that even a system like MAR could no longer deal with realistic attack scenarios, the Nike-X concept was abandoned in favor of much simpler concepts like the Sentinel program, which did not use MAR. A second example, MAR-II, was abandoned in-place on Kwajalein Atoll.

The first Soviet APAR, the 5N65, was developed in 1963-1965 as a part of the S-225 ABM system. After some modifications in the system concept in 1967 it was built at Sary Shagan Test Range in 1970-1971 and nicknamed Flat Twin in the West. Four years later another radar of this design was built on Kura Test Range, while the S-225 system was never commissioned.

 * The first military ground-based AESA was the J/FPS-3 which became fully operational with the 45th Aircraft Control and Warning Group of the Japan Self-Defense Forces in 1995.
 * The first series production ship-based AESA was the OPS-24, a fire-control radar introduced on the Japanese Asagiri-class destroyer DD-155 Hamagiri launched in 1988.
 * The first airborne series production AESA was the EL/M-2075 Phalcon on a Boeing 707 of the Chilean Air Force that entered service in 1994.
 * The first AESA on a combat aircraft was the J/APG-1 introduced on the Mitsubishi F-2 in 1995.
 * The first AESA on a missile is the seeker head for the AAM-4B, an air-to-air missile carried by the Mitsubishi F-2 and Mitsubishi-built McDonnell-Douglas F-15J.

US based manufacturers of the AESA radars used in the F-22 and Super Hornet include Northrop Grumman and Raytheon. These companies also design, develop and manufacture the transmit/receive modules which comprise the 'building blocks' of an AESA radar. The requisite electronics technology was developed in-house via Department of Defense research programs such as MMIC Program. In 2016 the Congress funded a military industry competition to produce new radars for two dozen National Guard fighter aircraft.

Basic concept
Radar systems generally work by connecting an antenna to a powerful radio transmitter to emit a short pulse of signal. The transmitter is then disconnected and the antenna is connected to a sensitive receiver which amplifies any echos from target objects. By measuring the time it takes for the signal to return, the radar receiver can determine the distance to the object. The receiver then sends the resulting output to a display of some sort. The transmitter elements were typically klystron tubes or magnetrons, which are suitable for amplifying or generating a narrow range of frequencies to high power levels. To scan a portion of the sky, the radar antenna must be physically moved to point in different directions.

Starting in the 1960s new solid-state devices capable of delaying the transmitter signal in a controlled way were introduced. That led to the first practical large-scale passive electronically scanned array (PESA), or simply phased array radar. PESAs took a signal from a single source, split it into hundreds of paths, selectively delayed some of them, and sent them to individual antennas. The radio signals from the separate antennas overlapped in space, and the interference patterns between the individual signals were controlled to reinforce the signal in certain directions, and mute it in all others. The delays could be easily controlled electronically, allowing the beam to be steered very quickly without moving the antenna. A PESA can scan a volume of space much quicker than a traditional mechanical system. Additionally, thanks to progress in electronics, PESAs added the ability to produce several active beams, allowing them to continue scanning the sky while at the same time focusing smaller beams on certain targets for tracking or guiding semi-active radar homing missiles. PESAs quickly became widespread on ships and large fixed emplacements in the 1960s, followed by airborne sensors as the electronics shrank.

AESAs are the result of further developments in solid-state electronics. In earlier systems the transmitted signal was originally created in a klystron or traveling wave tube or similar device, which are relatively large. Receiver electronics were also large due to the high frequencies that they worked with. The introduction of gallium arsenide microelectronics through the 1980s served to greatly reduce the size of the receiver elements until effective ones could be built at sizes similar to those of handheld radios, only a few cubic centimeters in volume. The introduction of JFETs and MESFETs did the same to the transmitter side of the systems as well. It gave rise to amplifier-transmitters with a low-power solid-state waveform generator feeding an amplifier, allowing any radar so equipped to transmit on a much wider range of frequencies, to the point of changing operating frequency with every pulse sent out. Shrinking the entire assembly (the transmitter, receiver and antenna) into a single "transmitter-receiver module" (TRM) about the size of a carton of milk and arraying these elements produces an AESA.

The primary advantage of an AESA over a PESA is the capability of the different modules to operate on different frequencies. Unlike the PESA, where the signal is generated at single frequencies by a small number of transmitters, in the AESA each module generates and radiates its own independent signal. This allows the AESA to produce numerous simultaneous "sub-beams" that it can recognize due to different frequencies, and actively track a much larger number of targets. AESAs can also produce beams that consist of many different frequencies at once, using post-processing of the combined signal from a number of TRMs to re-create a display as if there was a single powerful beam being sent. However, this means that the noise present in each frequency is also received and added.

Advantages
AESAs add many capabilities of their own to those of the PESAs. Among these are: the ability to form multiple beams simultaneously, to use groups of TRMs for different roles concurrently, like radar detection, and, more importantly, their multiple simultaneous beams and scanning frequencies create difficulties for traditional, correlation-type radar detectors.

Low probability of intercept
Radar systems work by sending out a signal and then listening for its echo off distant objects. Each of these paths, to and from the target, is subject to the inverse square law of propagation in both the transmitted signal and the signal reflected back. That means that a radar's received energy drops with the fourth power of the distance, which is why radar systems require high powers, often in the megawatt range, to be effective at long range.

The radar signal being sent out is a simple radio signal, and can be received with a simple radio receiver. Military aircraft and ships have defensive receivers, called "radar warning receivers" (RWR), which detect when an enemy radar beam is on them, thus revealing the position of the enemy. Unlike the radar unit, which must send the pulse out and then receive its reflection, the target's receiver does not need the reflection and thus the signal drops off only as the square of distance. This means that the receiver is always at an advantage [neglecting disparity in antenna size] over the radar in terms of range - it will always be able to detect the signal long before the radar can see the target's echo. Since the position of the radar is extremely useful information in an attack on that platform, this means that radars generally must be turned off for lengthy periods if they are subject to attack; this is common on ships, for instance.

Unlike the radar, which knows which direction it is sending its signal, the receiver simply gets a pulse of energy and has to interpret it. Since the radio spectrum is filled with noise, the receiver's signal is integrated over a short period of time, making periodic sources like a radar add up and stand out over the random background. The rough direction can be calculated using a rotating antenna, or similar passive array using phase or amplitude comparison. Typically RWRs store the detected pulses for a short period of time, and compare their broadcast frequency and pulse repetition frequency against a database of known radars. The direction to the source is normally combined with symbology indicating the likely purpose of the radar – airborne early warning and control, surface-to-air missile, etc.

This technique is much less useful against a radar with a frequency-agile (solid state) transmitter. Since the AESA (or PESA) can change its frequency with every pulse (except when using doppler filtering), and generally does so using a random sequence, integrating over time does not help pull the signal out of the background noise. Moreover, a radar may be designed to extend the duration of the pulse and lower its peak power. An AESA or modern PESA will often have the capability to alter these parameters during operation. This makes no difference to the total energy reflected by the target but makes the detection of the pulse by an RWR system less likely. Nor does the AESA have any sort of fixed pulse repetition frequency, which can also be varied and thus hide any periodic brightening across the entire spectrum. Older generation RWRs are essentially useless against AESA radars, which is why AESAs are also known as low probability of intercept radars. Modern RWRs must be made highly sensitive (small angles and bandwidths for individual antennas, low transmission loss and noise) and add successive pulses through time-frequency processing to achieve useful detection rates.

High jamming resistance
Jamming is likewise much more difficult against an AESA. Traditionally, jammers have operated by determining the operating frequency of the radar and then broadcasting a signal on it to confuse the receiver as to which is the "real" pulse and which is the jammer's. This technique works as long as the radar system cannot easily change its operating frequency. When the transmitters were based on klystron tubes this was generally true, and radars, especially airborne ones, had only a few frequencies to choose among. A jammer could listen to those possible frequencies and select the one to be used to jam.

Most radars using modern electronics are capable of changing their operating frequency with every pulse. This can make jamming less effective; although it is possible to send out broadband white noise to conduct barrage jamming against all the possible frequencies, this reduces the amount of jammer energy in any one frequency. An AESA has the additional capability of spreading its frequencies across a wide band even in a single pulse, a technique known as a "chirp". In this case, the jamming will be the same frequency as the radar for only a short period, while the rest of the radar pulse is unjammed.

AESAs can also be switched to a receive-only mode, and use these powerful jamming signals to track its source, something that required a separate receiver in older platforms. By integrating received signals from the targets' own radar along with a lower rate of data from its own broadcasts, a detection system with a precise RWR like an AESA can generate more data with less energy. Some receive beamforming-capable systems, usually ground-based, may even discard a transmitter entirely.

However, using a single receiving antenna only gives a direction. Obtaining a range and a target vector requires at least two physically separate passive devices for triangulation to provide instantaneous determinations, unless phase interferometry is used. Target motion analysis can estimate these quantities by incorporating many directional measurements over time, along with knowledge of the position of the receiver and constraints on the possible motion of the target.

Other advantages
Since each element in an AESA is a powerful radio receiver, active arrays have many roles besides traditional radar. One use is to dedicate several of the elements to reception of common radar signals, eliminating the need for a separate radar warning receiver. The same basic concept can be used to provide traditional radio support, and with some elements also broadcasting, form a very high bandwidth data link. The F-35 uses this mechanism to send sensor data between aircraft in order to provide a synthetic picture of higher resolution and range than any one radar could generate. In 2007, tests by Northrop Grumman, Lockheed Martin, and L-3 Communications enabled the AESA system of a Raptor to act like a WiFi access point, able to transmit data at 548 megabits per second and receive at gigabit speed; this is far faster than the Link 16 system used by US and allied aircraft, which transfers data at just over 1 Mbit/s. To achieve these high data rates requires a highly directional antenna which AESA provides but which precludes reception by other units not within the antennas beamwidth, whereas like most Wi-Fi designs, Link-16 transmits its signal omni-directionally to ensure all units within range can receive the data.

AESAs are also much more reliable than either PESAs or older designs. Since each module operates independently of the others, single failures have little effect on the operation of the system as a whole. Additionally, the modules individually operate at low powers, perhaps 40 to 60 watts, so the need for a large high-voltage power supply is eliminated.

Replacing a mechanically scanned array with a fixed AESA mount (such as on the Boeing F/A-18E/F Super Hornet) can help reduce an aircraft's overall radar cross-section (RCS), but some designs (such as the Eurofighter Typhoon and Gripen NG) forgo this advantage in order to combine mechanical scanning with electronic scanning and provide a wider angle of total coverage. This high off-nose pointing allows the AESA equipped fighter to employ a crossing the T maneuver, often referred to as "beaming" in the context of air-to-air combat, against a mechanically scanned radar that would filter out the low closing speed of the perpendicular flight as ground clutter while the AESA swivels 40 degrees towards the target in order to keep it within the AESA's 60 degree off-angle limit.

Limitations
With a half wavelength distance between the elements, the maximum beam angle is approximately $$\pm 45$$°. With a shorter element distance, the highest field of view (FOV) for a flat phased array antenna is currently 120° ($$\pm 60$$°), although this can be combined with mechanical steering as noted above.

Airborne systems

 * Aselsan
 * MURAD, for the Baykar Bayraktar Akıncı, F-16 and TAI TF-X Kaan
 * Captor-E CAESAR (CAPTOR Active Electronically Scanning Array Radar) for the Eurofighter Typhoon
 * Defence Research and Development Organisation
 * DRDO LSTAR - Radar for Airborne Early Warning platform.
 * Uttam AESA multifunction radar for HAL Tejas
 * Virupaaksha multifunction radar for Su-30MKI, an advance variant of Uttam AESA
 * Elta Systems
 * EL/M-2083 aerostat-mounted air search radar
 * EL/M-2052, for fighters. Interim candidate for HAL Tejas. Suitable for F-15, MiG-29, Mirage 2000, FA-50 Block 20.
 * EL/M-2075 radar for the IAI Phalcon AEW&C system
 * EL/W-2085 advanced version of the radar for the EL/M-2075, used on the Gulfstream G550
 * EL/W-2090 similar to the EL/W-2085, only used on the Ilyushin Il-76
 * Ericsson
 * Erieye AEW&C
 * PS-05/A MK-5 for JAS 39 Gripen.
 * EMB 145 AEW&C
 * Hanwha Systems
 * KF-21 radar for KAI KF-21 Boramae
 * LIG Nex1
 * ESR-500A air-cooled radar, roughly equivalent to Raytheon PhamtomStrike, option for KAI FA-50 Block 20
 * Mitsubishi Electric Corporation
 * J/APG-1 / J/APG-2 AESA for the Mitsubishi F-2 fighter
 * HPS-104 for the Mitsubishi SH-60
 * Multifunction RF Sensor for Mitsubishi ATD-X
 * Northrop Grumman
 * AN/APG-77, for the F-22 Raptor
 * AN/APG-80, for the General Dynamics F-16 Fighting Falcon
 * AN/APG-81, for the F-35 Lightning II
 * AN/APG-83, for the F-16V Viper and B-1B Lancer upgrades.
 * AN/APG-85, for the F-35 Lightning II (Block 4)
 * AN/APY-9, for the E-2D Advanced Hawkeye
 * Multi-role Electronically Scanned Array (MESA), for the Boeing E-7 Wedgetail
 * AN/ASQ-236 Podded AESA Radar
 * AN/ZPY-1 STARLite Small Tactical Radar - Lightweight, for manned and unmanned aircraft
 * AN/ZPY-2 Multi-Platform Radar Technology Insertion Program (MP-RTIP)
 * AN/ZPY-3 Multi-Function Active Sensor (MFAS) for MQ-4C Triton
 * NRIET (Nanjing Research Institute of Electronic Technology/14 institute), 607 institute, and 38 institute
 * Radar for KJ-2000 AEW&C system
 * Radar for KJ-500 & Y-7 AWACS
 * Radar for KJ-200
 * KLJ-7A for JF-17 Thunder Block 3
 * ZDK-03
 * Type 1475 Radar for Chengdu J-20
 * Chengdu J-10B/C
 * Shenyang J-16
 * Z-8AEW
 * Vehicle Dismount and Exploitation Radar (VADER)
 * Phazotron NIIR
 * Zhuk-A/AM, optional for MiG-35
 * Raytheon
 * AN/APG-63(V)2 and AN/APG-63(V)3, for the F-15C Eagle, Republic of Singapore's F-15SG
 * AN/APG-79, for the F/A-18E/F Super Hornet and EA-18G Growler
 * AN/APG-82(V)1 for the F-15E Strike Eagle & F-15EX Eagle II
 * AN/APG-84 RACR (Raytheon Advanced Combat Radar) for F-16 and F/A-18 upgrades.
 * AN/APQ-181 upgrade from PESA to AESA, for Northrop Grumman B-2 Spirit bomber
 * AN/APS-154 AAS (Advanced Airborne Sensor), AESA follow-on to LSRS (Littoral Surveillance Radar System), AN/APS-149. Also for the Boeing P-8 Poseidon
 * PhantomStrike air-cooled AESA radar for the FA-50 Block 20.
 * Raytheon Sentinel ASTOR (Airborne STand-Off Radar)
 * Saab
 * GlobalEye AEW&C, advanced version of the Erieye with extended range.
 * Selex ES (now Leonardo)
 * PicoSAR
 * Raven ES-05 AESA for the JAS-39E Gripen NG
 * Seaspray 5000E
 * Seaspray 7000E, for helicopters
 * Seaspray 7500E for General Atomics MQ-9 Reaper
 * Vixen 500E
 * Vixen 1000E
 * RBE2-AESA for Rafale fighter
 * Tikhomirov NIIP
 * N036 Byelka, for Sukhoi Su-57
 * Thales
 * RBE2-AESA for Rafale fighter
 * Toshiba
 * HPS-106, air & surface search radar, for the Kawasaki P-1 maritime patrol aircraft, three antenna arrays.
 * Vega Radio Engineering Corporation -
 * radar for Beriev A-100

Surface systems (land, maritime)
The first AESA radar employed on an operational warship was the Japanese OPS-24 manufactured by Mitsubishi Electric introduced on the JDS Hamagiri (DD-155), the first ship of the latter batch of the Asagiri-class destroyer, launched in 1988.

 * APAR (active phased array radar): Thales Netherlands' multifunction radar is the primary sensor of the Royal Netherlands Navy's De Zeven Provinciën class frigates, the German Navy's Sachsen class frigates, and the Royal Danish Navy's Ivar Huitfeldt class frigates. APAR is the first active electronically scanned array multifunction radar employed on an operational warship.
 * BAE Systems
 * SAMPSON multifunction radar for the UK's Type 45 destroyers
 * ARTISAN Type 997 multifunction radar for the UK's Type 23 and Type 26 Frigates and the Queen Elizabeth class aircraft carriers
 * Bharat Electronics
 * RAWL-03 - Multi Function Active phased array Air Surveillance Radar.
 * Naval Missile Defense Radar (NMDR) - S-Band Multi Function Active phased array Radar.
 * Cassidian
 * BÜR - Bodenüberwachungsradar by Cassidian, for the Bundeswehr
 * COBRA Counter-battery radar
 * TRS-4D
 * CEA Technologies
 * CEAFAR a 4th generation, S-Band multifunction digital active phased array radar, installed on all RAN ANZAC class frigates.
 * China
 * Road-mobile "Anti-Stealth" JY-26 "Skywatch-U" 3-D long-range air surveillance radar.
 * H/LJG-346(8) on Chinese aircraft carrier Liaoning
 * H/LJG-346 on Type 052C destroyer
 * H/LJG-346A on Type 052D destroyer
 * H/LJG-346B on Type 055 destroyer
 * Type 305A Radar (Acquisition radar for the HQ-9 missile system)
 * YLC-2 Radar
 * Defence Research and Development Organisation
 * Ashwini LLTR Radar- 4D AESA radar (used by Indian Air Force).
 * Arudhra Radar- Multi function AESA radar (used by Indian Air Force).
 * Swordfish Long Range Tracking Radar- Target acquisition and fire control radar for Indian Ballistic Missile Defence system.
 * Air Defence Tactical Control Radar (ADTCR) - Tactical control radar.
 * Atulya Air Defence Fire Control Radar (ADFCR) - X-band, 3D Fire control radar.
 * Elta
 * EL/M-2080 Green Pine ground-based early warning AESA radar
 * EL/M-2106 ATAR air defense fire control radar
 * EL/M-2180 - WatchR Guard Multi-Mode Staring Ground Surveillance Radar
 * EL/M-2248 MF-STAR multifunction naval radar
 * EL/M-2258 Advanced Lightweight Phased Array ALPHA multifunction naval radar
 * EL/M-2084 multimission radar (artillery weapon location, air defence and fire control)
 * EL/M-2133 WindGuard - Trophy active protection system radar
 * Hensoldt
 * TRML-4D
 * Larsen & Toubro
 * Air Defence Fire Control Radar System- 3D surveillance radar.
 * LIG Nex1
 * SPS-550K medium-range air and surface surveillance radar for Incheon-class frigates and Daegu-class frigates
 * Lockheed Martin
 * AN/TPQ-53 Counterfire Target Acquisition Radar
 * AN/SPY-7 Long Range Discrimination Radar
 * AN/MPQ-64A4 Sentinel
 * AN/TPY-4 3DELRR Three-Dimensional Expeditionary Long-Range Radar
 * MEADS's fire control radar
 * Mitsubishi Electric Corporation
 * Type 3 Chū-SAM Medium Range Surface-to-Air MissileSystem (Chu-SAM, SAM-4) multifunction radar
 * OPS-24 (The world's first Naval Active Electronically Scanned Array radar) on Asagiri-class destroyers, Murasame-class destroyer (1994) and Takanami-class destroyers
 * OPS-50 (FCS-3) on the Hyūga-class helicopter destroyer, Izumo-class helicopter destroyer and Akizuki-class destroyer (2010)
 * J/FPS-3 Japanese main ground-based air defense
 * J/FPS-5 Japanese ground-based next-generation missile defense radar
 * JTPS-P14 Transportable air defence radar
 * JTPS-P16 Counter-battery radar
 * National Chung-Shan Institute of Science and Technology
 * Sea eagle eye- Multi function AESA radar
 * NEC
 * J/TPS-102 Self-propelled ground-based radar, cylindrical array antenna.
 * NNIIRT 1L119 Nebo SVU mobile AESA 3-dimensional surveillance radar
 * Northrop Grumman
 * AN/TPS-80 Ground/air task-oriented radar (G/ATOR)
 * HAMMR Highly Adaptable Multi-Mission Radar
 * RADA Electronic Industries
 * RPS-10
 * RPS-15
 * RPS-40
 * RPS-42
 * RHS-44
 * Raytheon
 * FlexDAR Flexible Distributed Array Radar
 * U.S. National Missile defense Sea-based X-band Radar (XBR)
 * AN/TPY-2 Anti-Ballistic Missile radar that can stand alone or be a part of the THAAD ABM system
 * AN/SPY-3 multifunction radar for U.S. DD(X) and CVN-21 next-generation surface vessels
 * AN/SPY-6 Air and Missile Defense Radar (AMDR) multifunction radar for U.S. Arleigh Burke destroyers, Gerald R. Ford-class aircraft carrier
 * Cobra Judy Replacement (CJR)/Cobra King on USNS Howard O. Lorenzen (T-AGM-25)
 * AN/FPS-132 Upgraded Early Warning Radar (UEWR) - PAVE PAWS upgrade from PESA to AESA
 * KuRFS
 * Saab Group
 * GIRAFFE Radar: GIRAFFE 1X, GIRAFFE 4A, GIRAFFE 8A
 * Selex ES
 * KRONOS Land & Naval 3D multi-function radar
 * RAN-40L 3D EWR
 * RAT-31DL
 * RAT-31DL/M
 * Thales
 * Ground Master 200
 * Ground Master 400
 * Ground Master 200 MM
 * SMART-L MM
 * Sea Fire 500 on FREMM-ER frigates
 * Sea Master 400
 * Sea Watcher 100
 * ThalesRaytheonSystems
 * M3R
 * Toshiba
 * J/FPS-4 Cheaper than J/FPS-3, produced by Toshiba
 * JMPQ-P13 Counter-battery radar, Toshiba
 * VNIIRT Gamma DE mobile 3-dimensional solid-state AESA surveillance radar
 * 50N6A multifunctional radar of the Vityaz missile system and 42S6 "Morfey" ("Morpheus")

title: Active electronically scanned array


text:
Venus Express

Venus Express (VEX) was the first Venus exploration mission of the European Space Agency (ESA). Launched in November 2005, it arrived at Venus in April 2006 and began continuously sending back science data from its polar orbit around Venus. Equipped with seven scientific instruments, the main objective of the mission was the long term observation of the Venusian atmosphere. The observation over such long periods of time had never been done in previous missions to Venus, and was key to a better understanding of the atmospheric dynamics. ESA concluded the mission in December 2014.

History
The mission was proposed in 2001 to reuse the design of the Mars Express mission. However, some mission characteristics led to design changes: primarily in the areas of thermal control, communications and electrical power. For example, since Mars is approximately twice as far from the Sun as Venus, the radiant heating of the spacecraft is four times greater for Venus Express than Mars Express. Also, the ionizing radiation environment is harsher. On the other hand, the more intense illumination of the solar panels results in more generated photovoltaic power. The Venus Express mission also uses some spare instruments developed for the Rosetta spacecraft. The mission was proposed by a consortium led by D. Titov (Germany), E. Lellouch (France) and F. Taylor (United Kingdom).

The launch window for Venus Express was open from 26 October to 23 November 2005, with the launch initially set for 26 October 4:43 UTC. However, problems with the insulation from the Fregat upper stage led to a two-week launch delay to inspect and clear out the small insulation debris that migrated on the spacecraft. It was eventually launched by a Soyuz-FG/Fregat rocket from the Baikonur Cosmodrome in Kazakhstan on 9 November 2005 at 03:33:34 UTC into a parking Earth orbit and 1 h 36 min after launch put into its transfer orbit to Venus. A first trajectory correction maneuver was successfully performed on 11 November 2005. It arrived at Venus on 11 April 2006, after 153 days of journey, and fired its main engine between 07:10:29 and 08:00:42 UTC SCET to reduce its velocity so that it could be captured by Venusian gravity into a nine-day orbit of 400 by. The burn was monitored from ESA's Control Centre, ESOC, in Darmstadt, Germany.

Seven further orbit control maneuvers, two with the main engine and five with the thrusters, were required for Venus Express to reach its final operational 24-hour orbit around Venus.

Venus Express entered its target orbit at apoapsis on 7 May 2006 at 13:31 UTC, when the spacecraft was 151000000 km from Earth. At this point the spacecraft was running on an ellipse substantially closer to the planet than during the initial orbit. The polar orbit ranged between 250 and 66000 km over Venus. The periapsis was located almost above the North pole (80° North latitude), and it took 24 hours for the spacecraft to travel around the planet.

Venus Express studied the Venusian atmosphere and clouds in detail, the plasma environment and the surface characteristics of Venus from orbit. It also made global maps of the Venusian surface temperatures. Its nominal mission was originally planned to last for 500 Earth days (approximately two Venusian sidereal days), but the mission was extended five times: first on 28 February 2007 until early May 2009; then on 4 February 2009 until 31 December 2009; and then on 7 October 2009 until 31 December 2012. On 22 November 2010, the mission was extended to 2014. On 20 June 2013, the mission was extended a final time until 2015.

On 28 November 2014, mission control lost contact with Venus Express. Intermittent contact was reestablished on 3 December 2014, though there was no control over the spacecraft, likely due to exhaustion of propellant. On 16 December 2014, ESA announced that the Venus Express mission had ended. A carrier signal was still being received from the vehicle, but no data was being transmitted. Mission manager Patrick Martin expected the spacecraft would fall below 150 km in early January 2015, with destruction occurring in late January or early February. The spacecraft's carrier signal was last detected by ESA on 18 January 2015.

Instruments
ASPERA-4: An acronym for "Analyzer of Space Plasmas and Energetic Atoms," ASPERA-4 investigated the interaction between the solar wind and the Venusian atmosphere, determine the impact of plasma processes on the atmosphere, determine global distribution of plasma and neutral gas, study energetic neutral atoms, ions and electrons, and analyze other aspects of the near Venus environment. ASPERA-4 is a re-use of the ASPERA-3 design used on Mars Express, but adapted for the harsher near-Venus environment.

MAG: The magnetometer was designed to measure the strength of Venus's magnetic field and the direction of it as affected by the solar wind and Venus itself. It mapped the magnetosheath, magnetotail, ionosphere, and magnetic barrier in high resolution in three-dimensions, aid ASPERA-4 in the study of the interaction of the solar wind with the atmosphere of Venus, identify the boundaries between plasma regions, and carry planetary observations as well (such as the search for and characterization of Venus lightning). MAG was derived from the Rosetta lander's ROMAP instrument.

One measuring device was placed on the body of the craft. The identical second of the pair was placed the necessary distance away from the body by unfolding a 1 m long boom (carbon composite tube). Two redundant pyrotechnical cutters cut one loop of thin rope to free the power of metal springs. The driven knee lever rotated the boom perpendicularly outwards and latched it in place. Only the use of a pair of sensors together with the rotation of the probe allowed the spacecraft to resolve the small natural magnetic field beneath the disturbing fields of the probe itself. The measurements to identify the fields produced by the craft took place on the route from Earth to Venus. The lack of magnetic cleanness was due to the reuse of the Mars Express spacecraft bus, which did not carry a magnetometer. By combining the data from two-point simultaneous measurements and using software to identify and remove interference generated by Venus Express itself, it was possible to obtain results of a quality comparable to those produced by a magnetically clean craft.

VMC: The Venus Monitoring Camera is a wide-angle, multi-channel CCD. The VMC is designed for global imaging of the planet. It operated in the visible (VIS), ultraviolet (UV), and near infrared (NIR1 and NIR2) spectral ranges, and maps surface brightness distribution searching for volcanic activity, monitoring airglow, studying the distribution of unknown ultraviolet absorbing phenomenon at the cloud-tops, and making other science observations. It was derived in part from the Mars Express High Resolution Stereo Camera (HRSC) and the Rosetta Optical, Spectroscopic and Infrared Remote Imaging System (OSIRIS). The camera is based on a Kodak KAI-1010 Series, 1024 x 1024 pixel interline CCD, and included an FPGA to pre-process image data, reducing the amount transmitted to Earth. The consortium of institutions responsible for the VMC included the Max Planck Institute for Solar System Research, the Institute of Planetary Research at the German Aerospace Center and the Institute of Computer and Communication Network Engineering at Technische Universität Braunschweig. It is not to be confused with Visual Monitoring Camera mounted on Mars Express, of which it is an evolution.

PFS: The "Planetary Fourier Spectrometer" (PFS) should have operated in the infrared between the 0.9 μm and 45 μm wavelength range and was designed to perform vertical optical sounding of the Venus atmosphere. It should have performed global, long-term monitoring of the three-dimensional temperature field in the lower atmosphere (cloud level up to 100 kilometers). Furthermore, it should have searched for minor atmospheric constituents that may be present, but had not yet been detected, analyzed atmospheric aerosols, and investigated surface to atmosphere exchange processes. The design was based on a spectrometer on Mars Express, but modified for optimal performance for the Venus Express mission. However PFS failed during its deployment and no useful data was transmitted.

SPICAV: The "SPectroscopy for Investigation of Characteristics of the Atmosphere of Venus" (SPICAV) is an imaging spectrometer that was used for analyzing radiation in the infrared and ultraviolet wavelengths. It was derived from the SPICAM instrument flown on Mars Express. However, SPICAV had an additional channel known as SOIR (Solar Occultation at Infrared) that was used to observe the Sun through Venus's atmosphere in the infrared.

VIRTIS: The "Visible and Infrared Thermal Imaging Spectrometer" (VIRTIS) was an imaging spectrometer that observed in the near-ultraviolet, visible, and infrared parts of the electromagnetic spectrum. It analyzed all layers of the atmosphere, surface temperature and surface/atmosphere interaction phenomena.

VeRa: Venus Radio Science was a radio sounding experiment that transmitted radio waves from the spacecraft and passed them through the atmosphere or reflected them off the surface. These radio waves were received by a ground station on Earth for analysis of the ionosphere, atmosphere and surface of Venus. It was derived from the Radio Science Investigation instrument flown on Rosetta.

Climate of Venus
Starting out in the early planetary system with similar sizes and chemical compositions, the histories of Venus and Earth have diverged in spectacular fashion. It is hoped that the Venus Express mission data that was obtained can contribute not only to an in-depth understanding of how the Venusian atmosphere is structured, but also to an understanding of the changes that led to the current greenhouse atmospheric conditions. Such an understanding may contribute to the study of climate change on Earth.

In 2006, its research result identified the differences between Venus and Earth and started to observe routine climate changes.

Search for life on Earth
Venus Express was also used to observe signs of life on Earth from Venus orbit. In images acquired by the probe, Earth was less than one pixel in size, which mimics observations of Earth-sized planets in other planetary systems. These observations were then used to develop methods for habitability studies of exoplanets.

Timeline of the mission

 * 3 August 2005: Venus Express completed its final phase of testing at Astrium Intespace facility in Toulouse, France.
 * 7 August 2005: Venus Express arrived at the airport of the Baikonur Cosmodrome.
 * 16 August 2005: First flight verification test completed.
 * 22 August 2005: Integrated System Test-3.
 * 30 August 2005: Last major system test successfully started.
 * 5 September 2005: Electrical testing successful.
 * 21 September 2005: FRR (Fuelling Readiness Review) Ongoing.
 * 12 October 2005: Mating to the Fregat upper stage completed.
 * 21 October 2005: Contamination detected inside the fairing – launch on hold.
 * 5 November 2005: Arrival at launch pad.
 * 9 November 2005: Launch from Baikonur Cosmodrome at 03:33:34 UTC.
 * 11 November 2005: First trajectory correction maneuver successfully performed.
 * 17 February 2006: The main engine is fired successfully in a dress rehearsal for the arrival maneuver.
 * 24 February 2006: Second trajectory correction maneuver successfully performed.
 * 29 March 2006: Third trajectory correction maneuver successfully performed – on target for 11 April orbit insertion.
 * 7 April 2006: Command stack for orbit insertion maneuver is loaded on the spacecraft.
 * 11 April 2006: The Venus Orbit Insertion (VOI) is completed successfully, according to the following timeline:

 * {| class="wikitable"

!Event !Spacecraft event time (UTC) !Ground receive time (UTC)
 * Liquid Settling Phase start || 07:07:56 || 07:14:41
 * VOI main engine start || 07:10:29 || 07:17:14
 * periapsis passage || 07:36:35 ||
 * eclipse start || 07:37:46 ||
 * occultation start || 07:38:30 || 07:45:15
 * occultation end || 07:48:29 || 07:55:14
 * eclipse end || 07:55:11 ||
 * VOI burn end || 08:00:42 || 08:07:28
 * }
 * occultation start || 07:38:30 || 07:45:15
 * occultation end || 07:48:29 || 07:55:14
 * eclipse end || 07:55:11 ||
 * VOI burn end || 08:00:42 || 08:07:28
 * }
 * VOI burn end || 08:00:42 || 08:07:28
 * }
 * }

 * Period of this initial orbit is nine days.

 * 13 April 2006: First images of Venus from Venus Express released.
 * 20 April 2006: Apoapsis Lowering Manoeuvre #1 performed. Orbital period is now 40 hours.
 * 23 April 2006: Apoapsis Lowering Manoeuvre #2 performed. Orbital period is now approx 25 hours 43 minutes.
 * 26 April 2006: Apoapsis Lowering Manoeuvre #3 is slight fix to previous ALM.
 * 7 May 2006: Venus Express entered its target orbit at apoapsis at 13:31 UTC
 * 14 December 2006: First temperature map of the southern hemisphere.
 * 27 February 2007: ESA agrees to fund mission extension until May 2009.
 * 19 September 2007: End of the nominal mission (500 Earth days) – Start of mission extension.
 * 27 November 2007: A series of papers was published in Nature giving the initial findings. It finds evidence for past oceans. It confirms the presence of lightning on Venus and that it is more common on Venus than it is on Earth. It also reports the discovery that a huge double atmospheric vortex exists at the south pole of the planet.
 * 20 May 2008: The detection by the VIRTIS instrument of hydroxyl (OH) in the atmosphere of Venus is reported in the May 2008 issue of Astronomy & Astrophysics.
 * 4 February 2009: ESA agrees to fund mission extension until 31 December 2009.
 * 7 October 2009: ESA agrees to fund the mission through 31 December 2012.
 * 23 November 2010: ESA agrees to fund the mission through 31 December 2014.
 * 25 August 2011: It is reported that a layer of ozone exists in the upper atmosphere of Venus.
 * 1 October 2012: It is reported that a cold layer where dry ice may precipate exists in the atmosphere of Venus.
 * 18 June—11 July 2014: Performs successful aerobraking experiment. Multiple passes at 131 to 135 km altitude.
 * 28 November 2014: Mission control loses contact with Venus Express.
 * 3 December 2014: Intermittent contact established, spacecraft determined to likely be out of propellant.
 * 16 December 2014: ESA declares the Venus Express mission over.
 * 18 January 2015: Last detection of the spacecraft's X-band carrier signal.

title: Venus Express


text:
Alderson disk

An Alderson disk (named after Dan Alderson, its originator) is a hypothetical artificial astronomical megastructure, like Larry Niven's Ringworld and the Dyson sphere. The disk is a giant platter with a thickness of several thousand miles. The Sun rests in the hole at the center of the disk. The outer perimeter of an Alderson disk would be roughly equivalent to the orbit of Mars or Jupiter. According to the proposal, a sufficiently large disk would have a larger mass than its Sun.

The hole would be surrounded by a thousand-mile-high wall to prevent the atmosphere from drifting into the Sun. The outer rim would not require a wall.

The mechanical stresses within the disc would be far beyond what any known material can stand, thus relegating such a structure to the realm of exploratory engineering until materials and construction science become sufficiently advanced. Building a megastructure of this magnitude would require an amount of material that far surpasses the amount of material found in the Solar System.

Life could exist on either side of the disk, though life in close proximity to the sun would be impossible without sufficient heat protection. Conversely, beings residing far away from the Sun would freeze without the requisite heating equipment. Therefore, for the entirety of such a structure to be made habitable, it would have to include a vast number of life support systems. Even without such systems, the habitable surface area would be an equivalent of tens to hundreds of millions of Earths.

Because the Sun remains stationary, there is no day/night cycle, only a perpetual twilight. This could be solved by forcing the Sun to bob up and down within the disk, lighting first one side then the other.

In popular culture
In 1974, the science fiction writer Larry Niven suggested that an Alderson disk "would be a wonderful place to stage a gothic or sword and sorcery novel. The atmosphere is right, and there are real monsters." Because the zone habitable by humans is 'relatively narrow' (5% closer in and farther out than Earth's current orbit would provide 50 million times the surface area of Earth), the disc (and the cost of its construction) could be shared with aliens from hotter and colder planets. Over long periods of time, lifeforms would evolve to settle the sparsely-inhabited regions in between. "If civilization should fall, things could get eerie and interesting."

An Alderson disk (the Godwheel) was a prominent feature of Malibu Comics' Ultraverse. The Godwheel was split between two societies, one which used technology and one which used magic (each occupied its own side of the disk). Larry Niven designed the Godwheel and wrote stories surrounding certain events on it.

Rak Mesba is a partial ancient alien Alderson Disk in Orion's Arm, a multi-authored online science fiction world-building project.

A disk-shaped planet similar to an Alderson disk (though far smaller) served as the homeworld of the fantasy "Aysle" setting (or "cosm") of West End Games' Torg roleplaying game. In contrast with the Alderson disk, the Aysle "diskworld" works according to fantasy physics, including a "gravity plane" that bisects the disk laterally, so that opposite sides "fall" towards the plane. The diskworld of Aysle had a bobbing Sun and multiple inner layers. Both sides of the disk were inhabited, as were the internal layers.

In Charles Stross's Missile Gap, a copy of the whole Earth (along with copies of many other planets) is placed on an Alderson disk built around a black hole by unknown forces.

Ian McDonald's novel Empress of the Sun features a parallel-universe version of our solar system where creatures evolved from dinosaurs have converted all the mass to an Alderson disk (with a bobbing sun).

In Terry Pratchett's science fiction novel Strata the concept of an Alderson disk is brought up by the protagonist, Kin Arad, as an explanation for the mysterious 'flat earth' that is the focus of the story.

In Gigastructural Engineering & More, a popular modification to the 4X game Stellaris, the Alderson Disk is featured as a buildable megastructure inhabitable by the player.

In the game Honkai: Star Rail, the planet of Penacony is actually a large artificial space station-like megastructure housing a hotel surrounded by two small Alderson disks orbiting it.

title: Alderson disk