The HF200 is a height finder radar designed and first built by Decca Radar in 1957, and continuing sales into the 1970s after the division was purchased by Plessey in 1965. It was one of the company's successful heavy radar projects, winning the contract for many of the ROTOR stations in the UK and additional sales around the world with a total production run of about 40 examples. These served into the 1980s, and in one case, 1993, before 3D radars removed the need for separate height-finders.
158-721: Decca Heavy Radar won the contract to build the production models of the Green Garlic radar system developed by the Air Ministry 's Telecommunications Research Establishment (TRE) in the early 1950s. This was just prior to the TRE's merger with their British Army counterparts to form the Radar Research Establishment in 1953. Decca's version of the Green Garlic was given the name AMES Type 80 and
316-678: A HR scope , which displays range along the X-axis and vertical angle along the Y-axis. The operator moved a cursor, or strobe in UK parlance, so it laid under the selected target, which limited the nodding to a small angle on either side of the target. The altitude was measured compared to a curved line that represented the curvature of the Earth, as targets seen at longer distances would be at higher altitudes compared to closer ones due to this curvature. Once
474-551: A 500 knot bomber flying between 40,000 and 50,000 ft, the order to scramble must be given before the bomber is within fifteen minutes flying time, or 125 miles, from the coast. An additional five minutes are required for the appreciation to be made by the controller, and a further 3 + 1 ⁄ 2 minutes to allow for the delays from the first detection to display on the General Situation Map. These time allowances total 23 + 1 ⁄ 2 minutes, which represent
632-485: A 75% increase in effective range. Combining the new receiver with the more powerful magnetrons suggested a doubling of the effective range was possible. To test these concepts, the TRE built a lash-up system using two antennas from the Type 14 radars, placing them side by side on a Type 7 turntable, and replacing the Type 14's 500 kW cavity magnetron with a new 1.5 MW model. The resulting system had an antenna that
790-546: A Type 16 turntable. The system was operational in October 1952 and took part in that year's air war-games, Exercise Ardent . Ardent was, by far, the largest air exercise carried out since the war. RAF Bomber Command carried out a total of 2,000 sorties, met by 5,500 sorties by RAF Fighter Command . At its peak, the rate of sorties matched that of the Battle of Britain . Green Garlic proved to give "outstanding results" and
948-509: A Type 80 or Type 81 simply by moving the antenna between two pre-set positions. After some experimentation, the Type 81 name was dropped, and the new concept became the Type 80 Mark III. Another change was to allow the turntable to mount two antennas back-to-back. While this was being considered, the new 2 MW magnetron finally became available in quantity. These were added to the Mark III specification, offsetting any loss of range due to
1106-455: A distance of approximately 200 miles of early warning. The average range of early warning to be expected from ROTOR or the present CH stations is 130 miles. ... It will, therefore, be seen that the overriding requirement to enable interception to be made is the extension of early warning from the ROTOR figure of 130 miles to a minimum of 200 nautical miles. The ROTOR plans were taking place during
1264-538: A fashion similar to large conventional ones; the total damage caused by an atomic bomb was less than that of the thousand-bomber raids , and a single atomic attack was unlikely to eliminate a target. In this case, a protracted battle might occur in which the RAF and Army would seek to attrite the Soviet force so that follow-up attacks would become ineffective, essentially a damage-mitigation strategy. This thinking changed with
1422-475: A framework, the nationalist government classified all peoples into three races ( Whites , Blacks , Indians and Coloured people (people of mixed race) ) and developed rights and limitations for each. The white minority (less than 20%) controlled the vastly larger black majority. The legally institutionalised segregation became known as apartheid . While whites enjoyed the highest standard of living in all of Africa, comparable to First World Western nations,
1580-461: A generally temperate climate because it is surrounded by the Atlantic and Indian Oceans on three sides, because it is located in the climatically milder Southern Hemisphere , and because its average elevation rises steadily toward the north (toward the equator) and further inland. This varied topography and oceanic influence result in a great variety of climatic zones. The climatic zones range from
1738-699: A half after the discovery of the cape sea route, Jan van Riebeeck established a victualling station at the Cape of Good Hope, at what would become Cape Town , on behalf of the Dutch East India Company. In time, the cape became home to a large population of vrijlieden , also known as vrijburgers ( lit. ' free citizens ' ), former company employees who stayed in Dutch territories overseas after serving their contracts. Dutch traders also brought thousands of enslaved people to
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#17328008418131896-409: A high point of 62 years in 1992 to a low of 53 in 2005, and the failure of the government to take steps to address the pandemic in its early years. In May 2008, riots left over 60 people dead. The Centre on Housing Rights and Evictions estimated that over 100,000 people were driven from their homes. The targets were mainly legal and illegal migrants , and refugees seeking asylum, but a third of
2054-540: A horizon-scanning radar like the Hydra. This generated considerable interest at Decca, but was ultimately proven not to be useful and was not employed. This left an obvious hole in the UK market for a high-power height-finder with range that matched that of the Type 80, compared to the WWII -era AMES Type 13 which had an effective range perhaps 1 ⁄ 3 of the Type 80. Converting the Type 80 electronics to height-finding
2212-522: A period of intense political and economic crisis since 2020 with growing numbers of international institutions, businesses and political figures warning that the country risks collapsing into a failed state due to high unemployment, low economic growth, low business investment, rising levels of violent crime, disorder, political corruption, and state capture . The country has been undergoing an energy crisis since 2007, resulting in routine rolling electricity blackouts due to loadshedding . According to
2370-650: A period of rapid technical development at the UK's radar research establishments — the RAF-oriented Telecommunications Research Establishment (TRE), the Army-oriented Radar Research and Development Establishment (RRDE), and the Navy's Admiralty Signal Establishment . Among the important advances in the immediate post-war era were higher-power cavity magnetrons over 1 MW, and
2528-476: A period of significant upheaval, led to the formation of various African kingdoms, including the Zulu Kingdom . The region was further colonised, and diamonds and gold were discovered , bringing a shift towards industrialisation and urbanisation. The Union of South Africa was created in 1910 out of the former Cape , Natal , Transvaal , and Orange River colonies, becoming a republic in 1961 . Though
2686-408: A range of 320 nautical miles (590 km; 370 mi). For the new Type 80's 210 nmi nominal range, this meant it could see anything above about 22,000 feet (6,700 m). To gain familiarity with the design, and to compare its performance with earlier systems, TRE built a second experimental set. This used an example of the new antenna mounted back-to-back with the original Type 14 antenna on
2844-643: A rate of one per month. When these were complete, after a nine-month delay, construction would begin on the Type 81 stations, eventually reaching a total of twenty-one Type 81s. ROTOR III added another ten stations in Northern Ireland and western Scotland, completing the coverage of the British Isles. By this time a number of Type 80s were ready for service entry, although Trimmingham and the next installation at RAF St. Margarets were still being corrected for antenna position. One additional system
3002-442: A rather dramatic improvement over the roughly 50 nautical miles (93 km; 58 mi) maximum range of the original Type 14. Against an English Electric Canberra at 45,000 feet (14,000 m), the maximum range was increased to 230 to 250 nautical miles (430 to 460 km; 260 to 290 mi) and tracking range to 200 nautical miles (370 km; 230 mi). With relatively minor improvements, Green Garlic could fill most of
3160-718: A revaluation of this policy. These included the opening of the Korean War , the Berlin Airlift , and especially the test of the first Soviet atomic bomb in 1949. The Soviets were known to have built copies of the US Boeing B-29 as the Tupolev Tu-4 , which could reach the UK while carrying one of these weapons. Several new reports on air defence were quickly produced. By 1950 these had resulted in two broad deployment plans, ROTOR and VAST, covering systems in
3318-673: A second term in office by the National Assembly against the leader of the Economic Freedom Fighters , Julius Malema . South Africa is in southernmost Africa, with a coastline that stretches more than 2,500 km (1,553 mi) and along two oceans (the South Atlantic and the Indian). At 1,219,912 km (471,011 sq mi), South Africa is the 24th-largest country in the world. Excluding
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#17328008418133476-412: A series of Defense White Papers covering all of the armed forces, calling for a rapid drawdown of military strength. In the area of air defence, they suggested moving the emphasis to research and development , as they expected there would be rapid technological improvement over the next few years and there was no point building existing designs that would soon be obsolete. Events in the late 1940s led to
3634-585: A smaller network, mostly Type 80 Mark III's, dividing the country into nine sub-sectors. The entire air defence mission, from initial tracking to planning the interception, would be carried out entirely from these stations. Interceptions would be plotted on new 12 inches (300 mm) displays, while the overall image would be displayed on the Photographic Display Unit , which had originally been developed for ROTOR Phase II command centres. Within each sector, there would be multiple radars, with
3792-461: A subject of some embarrassment when it was revealed in the US press. The plan was ratified at a meeting on 21 June 1956. By June 1956 the sites of the original ROTOR II and III plans were being installed, although a number had been cancelled. Five Type 80 Mk. I's were in operation at Trimmingham, Beachy Head, St. Margarets, RAF Bempton , and RAF Ventnor . Three Mk. II's had been installed, one replacing
3950-480: A system of non-racial franchise had existed in the Cape, it was gradually eroded, and the vast majority of Black South Africans were not enfranchised until 1994. The National Party imposed apartheid in 1948, institutionalising previous racial segregation . After a largely non-violent struggle by the African National Congress and other anti-apartheid activists both inside and outside
4108-641: A system to automatically forward information from the radars to the SOCs and combine it onto a single large display. The cost of Phase I was enormous; £24 million for construction, £8.5 million for new electronics, and £19 million for telecommunications systems. In modern terms, this is £1816 million in 2023. In spite of this, the system was already seen to be almost useless. A report by the RAF Fighter Command 's Air Officer Commander in Chief stated: For
4266-405: A time-consuming process. If there was more than one radar in the area, or the aircraft moved into a different radar's view, all of this had to be repeated. The carcinotron could sweep so rapidly that it could barrage all potential frequencies, allowing it to jam all the radars in the area at the same time with little or no operator input. To test whether such a system would actually be effective,
4424-627: A transition of policies and government. In 1990, the National Party government took the first step towards dismantling discrimination when it lifted the ban on the ANC and other political organisations. It released Nelson Mandela from prison after 27 years of serving a sentence for sabotage. A negotiation process followed. With approval from the white electorate in a 1992 referendum , the government continued negotiations to end apartheid. South Africa held its first universal elections in 1994 , which
4582-569: A truncated cone with the radio equipment in the base. A prominent waveguide carried the signal to and from the antenna feedhorn through a rotating joint behind the antenna. Green Garlic The AMES Type 80 , sometimes known by its development rainbow code Green Garlic , was a powerful early warning (EW) and ground-controlled interception (GCI) radar developed by the Telecommunications Research Establishment (TRE) and built by Decca for
4740-400: A wide band of the microwave region by changing the input voltage. By sweeping the transmission through the entire frequency band of the radars the aircraft might meet, the jammer would fill the radar display with noise that would render the aircraft invisible. Older jammer systems could do this, but only after isolating the radar frequencies being used and tuning their transmitters to match them,
4898-460: A year in continued operations. Almost all design effort within the TRE switched to the Stage IA, leaving little manpower available for the original MEW. MEW's development was spun off to Marconi Wireless Telephones . Development of a production version of Green Garlic was mostly concerned with the design of an antenna that would provide more vertical coverage than the horizon-scanning pattern of
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5056-593: Is considered one of the most unequal countries in the world, if not the most unequal. The name "South Africa" is derived from the country's geographic location at the southern tip of Africa. Upon formation, the country was named the Union of South Africa in English and Unie van Zuid-Afrika in Dutch , reflecting its origin from the unification of four British colonies. Since 1961, the long formal name in English has been
5214-666: Is known as Namaqualand , which becomes more arid near the Orange River. The little rain that falls tends to fall in winter, which results in one of the world's most spectacular displays of flowers carpeting huge stretches of veld in spring (August–September). South Africa also has one offshore possession, the small sub-Antarctic archipelago of the Prince Edward Islands, consisting of Marion Island (290 km or 110 sq mi) and Prince Edward Island (45 km or 17 sq mi) South Africa has
5372-586: Is often referred to as the " rainbow nation " to describe the country's multicultural diversity, especially in the wake of apartheid. Recognised as a middle power in international affairs, it maintains significant regional influence and is a member of BRICS , the African Union , SADC , SACU , the Commonwealth of Nations , and the G20 . A developing , newly industrialised country , South Africa has
5530-481: Is rare. The coldest place on mainland South Africa is Buffelsfontein in the Eastern Cape , where a temperature of −20.1 °C (−4.2 °F) was recorded in 2013. The Prince Edward Islands have colder average annual temperatures, but Buffelsfontein has colder extremes. The deep interior of mainland South Africa has the hottest temperatures: a temperature of 51.7 °C (125.06 °F) was recorded in 1948 in
5688-722: Is surrounded by the Great Escarpment whose eastern, and highest, stretch is known as the Drakensberg . Mafadi in the Drakensberg at 3,450 m (11,320 ft) is the highest peak. The KwaZulu-Natal–Lesotho international border is formed by the highest portion of the Great Escarpment which reaches an altitude of over 3,000 m (9,800 ft). The south and south-western parts of the plateau (at approximately 1,100–1,800 m above sea level) and
5846-479: The Dutch East India Company were shipwrecked at the cape for several months. The sailors were able to survive by obtaining fresh water and meat from the natives. They also sowed vegetables in the fertile soil. Upon their return to Holland, they reported favourably on the cape's potential as a "warehouse and garden" for provisions to stock passing ships for long voyages. In 1652, a century and
6004-613: The Highveld . This relatively well-watered area is home to a great proportion of the country's commercial farmlands and contains its largest conurbation (Gauteng). To the north of Highveld, from about the 25° 30' S line of latitude, the plateau slopes downwards into the Bushveld , which ultimately gives way to the Limpopo River lowlands or Lowveld . The coastal belt, below the Great Escarpment, moving clockwise from
6162-704: The Indian Ocean trade . The events around Mapungubwe's collapse circa 1300 are unknown, however trade routes shifted north from the Limpopo to the Zambezi , precipitating the rise of Great Zimbabwe . The hill was abandoned and Mapungubwe's population scattered. In 1487, the Portuguese explorer Bartolomeu Dias led the first European voyage to land in southern Africa. On 4 December, he landed at Walfisch Bay (now known as Walvis Bay in present-day Namibia). This
6320-869: The International Court of Justice regarding Israel 's conduct in the Gaza Strip as part of the Israel–Hamas war , alleging that Israel had committed and was committing genocide against Palestinians in the Gaza Strip. South Africa has repeatedly hosted senior leaders of Hamas , the group responsible for the October 7th massacre in Israel. Following the 2024 general elections , the African National Congress saw its share of
6478-495: The International Monetary Fund , South Africa is suffering from "massive corruption" and state capture. The Zondo Commission , established in 2018 in order to investigate allegations of corruption and state capture released its findings in 2022. It found rampant corruption at every level of government, including Transnet , Eskom , and Denel , as well as law enforcement , intelligence agencies , and
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6636-745: The Native Location Act of 1879 and the system of pass laws . Eight years after the end of the Second Boer War and after four years of negotiation, the South Africa Act 1909 granted nominal independence while creating the Union of South Africa on 31 May 1910. The union was a dominion that included the former territories of the Cape, Transvaal and Natal colonies, as well as the Orange Free State republic. The Natives' Land Act of 1913 severely restricted
6794-760: The Outeniqua and Langeberg ranges to the south and the Swartberg range to the north is known as the Little Karoo , which consists of semi-desert shrubland similar to that of the Great Karoo, except that its northern strip along the foothills of the Swartberg Mountains has a somewhat higher rainfall and is, therefore, more cultivated than the Great Karoo. The Little Karoo is famous for its ostrich farming around Oudtshoorn . The lowland area to
6952-962: The Pedi people . King Sekhukhune managed to defeat the army on 1 August 1876. Another attack by the Lydenburg Volunteer Corps was also repulsed. On 16 February 1877, the two parties signed a peace treaty at Botshabelo . The Boers' inability to subdue the Pedi led to the departure of Burgers in favour of Paul Kruger and the British annexation of the South African Republic. In 1878 and 1879 three British attacks were successfully repelled until Garnet Wolseley defeated Sekhukhune in November 1879 with an army of 2,000 British soldiers, Boers and 10,000 Swazis. The Anglo-Zulu War
7110-498: The Prince Edward Islands , the country lies between latitudes 22° and 35°S , and longitudes 16° and 33°E . The interior of South Africa consists of a large, in most places almost flat plateau with an altitude of between 1,000 m (3,300 ft) and 2,100 m (6,900 ft), highest in the east and sloping gently downwards towards the west and north, and slightly so to the south and south-west. This plateau
7268-597: The ROTOR plan to provide radar coverage over the UK in a phased rollout. As part of Stage 2, a new EW radar with long range would be deployed starting in 1957. A TRE research project, Green Garlic, appeared to be able to fill this role. The first examples of the Type 80 were being installed in 1953 and became operational in 1955. New sites received updated Mark III models and some formed the Master Radar Stations ( MRS ) that directly directed air defences, filling
7426-655: The Republic of South Africa ( RSA ), is the southernmost country in Africa . Its nine provinces are bounded to the south by 2,798 kilometres (1,739 miles) of coastline that stretches along the South Atlantic and Indian Ocean ; to the north by the neighbouring countries of Namibia , Botswana , and Zimbabwe ; to the east and northeast by Mozambique and Eswatini ; and it encloses Lesotho . Covering an area of 1,221,037 square kilometres (471,445 square miles),
7584-474: The Royal Air Force (RAF). It could reliably detect a large fighter or small bomber at ranges over 210 nautical miles (390 km; 240 mi), and large, high-flying aircraft were seen out to the radar horizon . It was the primary military ground-based radar in the UK from the mid-1950s into the late 1960s, providing coverage over the entire British Isles . In the late 1940s, the RAF developed
7742-529: The Royal Canadian Air Force for operations around Metz . Four were used in Sweden . Potential sales for NADGE lost to a system from Thomson-CSF . The Swedish examples, Tom, Dick, Harry and Fred, were in use until 1978/79. The last Type 80, at RAF Buchan , shut down in 1993 after 37 years of operation. A total of about 35 Type 80s were built. By the middle of 1943, the UK's radar network
7900-405: The Second Boer War (1899–1902) and, although suffering heavy casualties due to Boer attrition warfare , they were ultimately successful due in part to scorched earth tactics such as concentration camps , in which 27,000 Boer civilians died due to a combination of disease and neglect. South Africa's urban population grew rapidly from the end of the 19th century onward. After the devastation of
8058-474: The South African Party and National Party merged to form the United Party , seeking reconciliation between Afrikaners and English-speaking whites. In 1939, the party split over the entry of the union into World War II, as an ally of the United Kingdom, a move which National Party followers opposed. In 1948, the National Party was elected to power. It strengthened the racial segregation begun under Dutch and British colonial rule. Taking Canada's Indian Act as
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#17328008418138216-405: The South African Republic , the Natalia Republic , and the Orange Free State . In the interior, the Cape Colony expanded at the expense of the Batswana and Griqua , and Boer expansion caused great instability in the Middle Orange River region. The Matabele kingdom came to dominate the eastern interior, and raided the Venda kingdom. The discovery of diamonds in 1867 and gold in 1884 in
8374-405: The Vaal River valley. Settlements of Bantu-speaking peoples , who were iron-using agriculturists and herdsmen , were present south of the Limpopo River (now the northern border with Botswana and Zimbabwe ) by the 4th or 5th century CE. The Bantu slowly moved south. The earliest ironworks in modern-day KwaZulu-Natal Province are believed to date from around 1050. The southernmost group
8532-677: The Xhosa Wars , as both sides competed for the pastureland near the Great Fish River, which the colonists desired for grazing cattle. Vrijburgers who became independent farmers on the frontier were known as Boers , with some adopting semi-nomadic lifestyles being denoted as trekboers . The Boers formed loose militias , which they termed commandos , and forged alliances with Khoisan peoples to repel Xhosa raids. Both sides launched bloody but inconclusive offensives, and sporadic violence, often accompanied by livestock theft, remained common for several decades. Great Britain occupied Cape Town between 1795 and 1803 to prevent it from falling under
8690-472: The civil service . It documented evidence of systemic corruption , fraud , racketeering , bribery , money laundering , and state capture. It investigated the African National Congress party and Jacob Zuma, whom it concluded were complicit in state capture through their direct assistance to the Gupta family . "The Commission estimated the total amount of money spent by the state which was 'tainted' by state capture to be around R57 billion. More than 97% of
8848-441: The largest economy in Africa by nominal GDP. It is tied with Ethiopia for the most UNESCO World Heritage Sites in Africa, and is a biodiversity hotspot with unique biomes , plant, and animal life. Since the end of apartheid, government accountability and quality of life have substantially improved. However, crime , poverty , and inequality remain widespread. Having the highest Gini coefficient of 0.63, South Africa
9006-424: The "Republic of South Africa" and Republiek van Suid-Afrika in Afrikaans . The country has an official name in 12 official languages . Mzansi , derived from the Xhosa noun uMzantsi meaning "south", is a colloquial name for South Africa, while some Pan-Africanist political parties prefer the term " Azania ". South Africa contains some of the oldest archaeological and human-fossil sites in
9164-550: The "comprehensive" stations running the operations as a whole, with backup radars, either GCI or early warning, feeding them information. This deployment plan had three phases; the first would simply build new command and control centres at eight of the existing GCI sites and build a new one at Farrid Head, phase two would convert another 19 ROTOR sites to "satellite" stations, and finally, the system would be tied together and automated with computer systems. These new comprehensive radar stations, later known as Master Radar Stations, had
9322-456: The 14th largest emitter of carbon dioxide, primarily from its heavy reliance on coal and oil for energy production . As part of its international commitments, South Africa has pledged to peak emissions between 2020 and 2025. South Africa signed the Rio Convention on Biological Diversity on 4 June 1994 and became a party to the convention on 2 November 1995. It has subsequently produced a National Biodiversity Strategy and Action Plan , which
9480-421: The AMES Type 81. However, as the Type 14 was seen as adequate in the short term, this project was given lower priority. Within the RAF, a new term began to be used, a "horizon limited radar", a system that could see anything above the radar horizon . Due to the curvature of the Earth, and assuming the maximum possible altitude of an air-breathing aircraft was about 60,000 feet (18,000 m), this corresponds to
9638-514: The ANC won by an overwhelming majority. It has been in power ever since. The country rejoined the Commonwealth of Nations and became a member of the Southern African Development Community . In post-apartheid South Africa, unemployment remained high. While many black people have risen to middle or upper classes, the overall unemployment rate of black people worsened between 1994 and 2003 by official metrics but declined significantly using expanded definitions. Poverty among white South Africans, which
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#17328008418139796-407: The Cherry Report. It outlined a number of problems in the existing network and suggested a slow improvement to the equipment over the next decade. Much of the work detailed ways to improve the system by sending all of the radar data from the outlying stations to Master GCI stations, instead of having to hand data from station to station as aircraft moved about. The Cherry Report was soon followed by
9954-463: The Congo , Rwanda , Eritrea , Ethiopia and Somalia . Competition over jobs, business opportunities, public services and housing has led to tension between refugees and host communities. While xenophobia in South Africa is still a problem, the United Nations High Commissioner for Refugees in 2011 reported that recent violence had not been as widespread as initially feared. Nevertheless, as South Africa continues to grapple with racial issues, one of
10112-426: The GCI role as well. The original ROTOR plans for over 60 stations was reduced by half, retaining only a small number of older radars to fill gaps. Many of the ROTOR operations rooms , only recently completed, were sold off. The system was developed during a period of rapid development in both radar technology and the nature of the strategic threat. The introduction of the hydrogen bomb led to serious questions about
10270-405: The HF200 was completed in 1957 and set up behind Decca's development site on Davis Road in Chessington on the outskirts of London . By this time the MoD began working on their new Linesman/Mediator network. Linesman included the new AMES Type 85 radar, a 3D radar that performed height-finding as well as PPI, so the need for HF200 was reduced. But the plans also called for a number of sites in
10428-451: The Lowveld covering 19,633 square kilometres (7,580 sq mi) The coastal belt below the south and south-western stretches of the Great Escarpment contains several ranges of Cape Fold Mountains which run parallel to the coast, separating the Great Escarpment from the ocean. (These parallel ranges of fold mountains are shown on the map, above left. Note the course of the Great Escarpment to the north of these mountain ranges.) The land between
10586-407: The Mk. I at Saxa Vord, one at RAF Aird Uig and another at RAF Killard Point . Fourteen Mk. III stations were in various stages of completion. By February 1957, the plan had once again fallen behind schedule. The delivery date for the first of the twelve remaining units was pushed back to October 1957, with the network supposed to be fully completed by October 1958. At a meeting on 8 January 1959,
10744-409: The Ndwandwe, however were repelled by Gaza. During the early 19th century, many Dutch settlers departed from the Cape Colony , where they had been subjected to British control, in a series of migrant groups who came to be known as Voortrekkers , meaning "pathfinders" or "pioneers". They migrated to the future Natal , Free State, and Transvaal regions. The Boers founded the Boer republics :
10902-406: The North Sea, and several more were used for air traffic control . Some of the Mark I models shut down as early as 1959 as the Mark III's increased range began filling gaps. Most of the UK fleet shut down in the late 1960s as Linesman's AMES Type 85s came online. The Type 80 also saw some overseas use by the RAF, with stations in Germany , Cyprus , Malta and Christmas Island . One was used by
11060-454: The Northern Cape Kalahari near Upington , but this temperature is unofficial and was not recorded with standard equipment; the official highest temperature is 48.8 °C (119.84 °F) at Vioolsdrif in January 1993. Climate change in South Africa is leading to increased temperatures and rainfall variability. Extreme weather events are becoming more prominent. This is a critical concern for South Africans as climate change will affect
11218-414: The PPI wanted to measure the altitude of a given blip on their screen, they would press a button as the radar swept by the target, sending the angle of the target to a separate height-finder operator. The operator would then accept the angle coordinate and slew the HF200's antenna to that angle. The HF200 would then begin "nodding" up and down to measure the altitude. The returns were displayed as blips on
11376-565: The R57 billion came from Transnet and Eskom. Out of these funds, the Gupta enterprise received at least R15 billion. The total loss to the state is difficult to quantify, but would far exceed that R15 billion." South Africa has maintained a position of neutrality in regards to the Russia invasion of Ukraine in 2022 and the ongoing war . On 29 December 2023, South Africa formally submitted its case to
11534-598: The RAF had considered several solutions to the original Phase II GCI requirement, including the Royal Navy 's new Type 984 radar , the Army's Orange Yeoman , and an adaptation of the Type 80. By mid-1953, the Air Ministry made the firm decision to use the Type 80-derived Type 81 rather than the other designs. Because the Type 81 spread its signal over a much greater vertical angle, the amount of energy in any given area
11692-409: The RAF purchased a carcinotron from the designers at CSF and fitted it to an aircraft christened Catherine . In tests beginning in late 1954, the jammer proved to be able to render the area around the aircraft unreadable, even when the aircraft was still below the radar horizon. In one test, any aircraft 20 miles (32 km) to either side of the jammer was invisible. As the jammer aircraft approached
11850-829: The South African National Biodiversity Institute, parts of southern Africa will see an increase in temperature by about 1 °C (1.8 °F) along the coast to more than 4 °C (7.2 °F) in the already hot hinterland such as the Northern Cape in late spring and summertime by 2050. The Cape Floral Region is predicted to be hit very hard by climate change. Drought, increased intensity and frequency of fire, and climbing temperatures are expected to push many rare species towards extinction. South Africa has published two national climate change reports in 2011 and 2016. South Africa contributes considerable carbon dioxide emissions , being
12008-677: The South African government because of its racial policies. The boycotts and restrictions were later extended to international sanctions and the divestment of holdings by foreign investors. The Mahlabatini Declaration of Faith , signed by Mangosuthu Buthelezi and Harry Schwarz in 1974, enshrined the principles of peaceful transition of power and equality for all, the first of such agreements by black and white political leaders in South Africa. Ultimately, F.W. de Klerk opened bilateral discussions with Nelson Mandela in 1993 for
12166-590: The Soviet Joe 4 test in August 1953. While not a true hydrogen bomb , it was clear it would not be long before they had one, which came to pass in late 1955 with the RDS-37 test. In contrast to fission weapons, which had to be delivered relatively close to their targets, the hydrogen bomb was so powerful that it could be dropped within miles and still be effective, especially in a strategic role against cities. With
12324-423: The Type 14. A further increase in angular resolution was also desirable, and these two features led to a much larger antenna. This, in turn, led to the need for a more robust turntable than the Type 7. An added advantage of the larger antenna would be that the energy of the beam would be concentrated into a smaller angle, only 1 ⁄ 3 of a degree. This allowed it to overpower jammers, a significant problem for
12482-497: The Type 7 where roughly 500 kW of power was spread over a 3 degree width. An order for eight production units was delivered in July 1952, with Decca building the electronics, Currans the turntable assembly, and Starkie Gardiner the 75 by 25 foot (22.9 m × 7.6 m) semi-parabolic reflector antenna. At this time the system was given the name AMES Type 80, separating them from wartime designs that were numbered in
12640-468: The Type 80, Decca turned its attention to other roles that might make use of the same electronics. Decca had contacts with the French company SNERI who had developed a radar clutter suppression system. This was considered for inclusion on a number of Decca radars of the era, notably their Decca Hydra military early warning radar . SNERI had also been working on a system to extract height information from
12798-655: The UK and overseas, respectively. ROTOR was to be a two-phase program, initially providing coverage only in the "Core Defended Area" around London , and then gradually expanding to cover the entire British Isles over time. For Phase I, 28 of the wartime radar sites would be upgraded with new electronics, a further 14 "Chain Early Warning" stations using the Type 14 and Type 13 would be added, along with 8 new GCI stations with upgraded Type 7's. Many other wartime stations would be shut down. Control would be divided among six Sector Operations Centres, coordinating reports from
12956-632: The UK market, NATO was undertaking its "high performing reporting post" program which would emerge as the NADGE system. Decca ultimately dropped out of NADGE, and their needs were filled by a system from Marconi Electronic Systems . The MoD then took over funding of further development of the Decca unit to replace the Type 13 as well as the General Electric AN/FPS-6 Radar which were being used in some number. The first example of
13114-524: The US. The HF200's generally went out-of-service as newer radars replaced the Type 80s. The last operational example appears to be the unit at Saxa Vord, which was installed beginning in 1977 and became operational in 1979. It remained in service until 1993 when the station's Marconi S649 radar was replaced by the AMES Type 93 , a 3D radar. The system was designed to work with the Type 80 or similar plan-position indicator (PPI) radars; when an operator on
13272-441: The accuracy demands greatly reduced there was no need for the bomber to fly over the target for aiming, one could drop the bomb from long range or use a booster to form a simple stand-off missile . This meant the close-in defence offered by the ROTOR system was largely useless; the enemy bombers would now have to be stopped well before they reached their target areas. The RAF spent much of 1955 considering how these changes affected
13430-529: The adjoining plain below (at approximately 700–800 m above sea level – see map on the right) is known as the Great Karoo , which consists of sparsely populated shrubland . To the north, the Great Karoo fades into the more arid Bushmanland, which eventually becomes the Kalahari Desert in the north-west of the country. The mid-eastern and highest part of the plateau is known as
13588-667: The arrival of the 1820 Settlers . The new colonists were induced to settle for a variety of reasons, namely to increase the size of the European workforce and to bolster frontier regions against Xhosa incursions. In the early 1800s, the Mfecane (lit. 'crushing') saw a heightened period of conflict, migration, and state formation among native groups, caused by the complex interplay of international trade, environmental instability, and European colonisation. Chiefdoms grew wealthier and competed over trade routes and grazing land, leading to
13746-581: The black majority remained disadvantaged by almost every standard, including income, education, housing, and life expectancy. The Freedom Charter , adopted in 1955 by the Congress Alliance , demanded a non-racial society and an end to discrimination. On 31 May 1961, the country became a republic following a referendum (only open to white voters) which narrowly passed; the British-dominated Natal province largely voted against
13904-402: The coast, and local reflections were avoided by the much narrower beam of the radar, which could aim away from obstructions. This implied that the number of stations in the network could be reduced significantly. It was during this same period that the growing concern over the carcinotron valve entered the discussion. First announced publicly in 1953, the carcinotron could rapidly tune across
14062-554: The coast, which is subtropical . The Free State is particularly flat because it lies centrally on the high plateau. North of the Vaal River , the Highveld becomes better watered and does not experience subtropical extremes of heat. Johannesburg, in the centre of the Highveld, is at 1,740 m (5,709 ft) above sea level and receives an annual rainfall of 760 mm (29.9 in). Winters in this region are cold, although snow
14220-760: The control of the French First Republic , which had invaded the Low Countries . After briefly returning to Dutch rule under the Batavian Republic in 1803, the cape was occupied again by the British in 1806. Following the end of the Napoleonic Wars , it was formally ceded to Great Britain and became an integral part of the British Empire . British emigration to South Africa began around 1818, subsequently culminating in
14378-520: The country has over 62 million people . Pretoria is the administrative capital, while Cape Town , as the seat of Parliament , is the legislative capital. Bloemfontein has traditionally been regarded as the judicial capital. The largest and most populous city is Johannesburg , followed by Cape Town and the busiest port city in sub-Saharan Africa, Durban . Archaeological findings suggest that various hominid species existed in South Africa about 2.5 million years ago, and modern humans inhabited
14536-404: The country, the repeal of discriminatory laws began in the mid-1980s. Universal elections took place in 1994 , following which all racial groups have held political representation in the country's liberal democracy , which comprises a parliamentary republic and nine provinces. South Africa is a multi-ethnic society encompassing a wide variety of cultures , languages , and religions ; it
14694-470: The coverage would extend over the entire British Isles. For both phases of ROTOR, shorter-range radars like the Type 7 and Type 14 would continue to fill the GCI role. It was understood that the GCI radars would have to be replaced at some point, and even by 1950 there were several radar systems under consideration for this role. The two Phase II concepts were formalized under Operational Requirements OR2047 for
14852-420: The cursor was properly positioned, the operator pressed another button which calculated the resulting altitude and sent the value back to the original PPI operator, where it appeared on a secondary display beside the primary PPI. The antenna used the "orange peel" design, generating a beam about 3º wide and 3 ⁄ 4 º high. The antenna was nodded and rotated hydraulically. The system was normally mounted on
15010-493: The early warning system, and OR2046 for the GCI system. It was also realized that passing the information from the early warning to the GCI radars would be problematic, so ROTOR also called for the construction of six Sector Operation Centers (SOCs) to coordinate the information being provided from the EW radars. Four of these were newly built underground bunkers , while two were rebuilt from WWII control centres. Plans began to develop
15168-430: The end of 1955. Several improvements were considered as the construction of the original units continued, including the addition of a new 2 MW magnetron and a pressurized waveguide system to keep humidity out of the piping to prevent arcing. In January 1957, the installation at RAF Saxa Vord was subjected to 90 nautical miles (170 km; 100 mi) wind loads which strained the antenna, and demanded changes to
15326-532: The existing radar systems would not see them on their high trajectories far above the horizon. These missiles were simpler and less expensive than the intercontinental ballistic missiles (ICBMs), which meant they would be deployed earlier, likely by the mid-1960s. They had low accuracy, but when armed with hydrogen bombs, they were capable of hitting the V-bomber bases and rendering the UK deterrent force impotent. South Africa South Africa , officially
15484-550: The extreme desert of the southern Namib in the farthest northwest to the lush subtropical climate in the east along the border with Mozambique and the Indian Ocean. Winters in South Africa occur between June and August. The extreme southwest has a climate similar to that of the Mediterranean with wet winters and hot, dry summers, hosting the famous fynbos biome of shrubland and thicket . This area produces much of
15642-1339: The first hominin fossil discovered in Africa, the Taung Child (found near Taung ) in 1924. Other hominin remains have come from the sites of Makapansgat in Limpopo Province; Cornelia and Florisbad in Free State Province ; Border Cave in KwaZulu-Natal Province; Klasies River Caves in Eastern Cape Province; and Pinnacle Point , Elandsfontein and Die Kelders Cave in Western Cape Province. These finds suggest that various hominid species existed in South Africa from about three million years ago, starting with Australopithecus africanus , followed by Australopithecus sediba , Homo ergaster , Homo erectus , Homo rhodesiensis , Homo helmei , Homo naledi and modern humans ( Homo sapiens ). Modern humans have inhabited Southern Africa for at least 170,000 years. Various researchers have located pebble tools within
15800-535: The fledgling colony from Indonesia , Madagascar , and parts of eastern Africa. Some of the earliest mixed race communities in the country were formed between vrijburgers , enslaved people, and indigenous peoples. This led to the development of a new ethnic group, the Cape Coloureds , most of whom adopted the Dutch language and Christian faith. The Khoisan people, comprising the Khoikhoi and San, were
15958-475: The formation of the Ndwandwe and Mthethwa Paramountcies in the east. Ndwandwe defeated Mthethwa which split into different groups, one of which was led by Shaka of the amaZulu . The 1810s saw the fourth and fifth Xhosa Wars as British colonisation expanded. Ndwandwe splintered amid costly raids and Shaka's Zulu Kingdom rose to fill the power vacuum. The Gaza kingdom formed. The Zulu totally defeated
16116-454: The increase in vertical angle. This also led to the curious situation that the new Mark III radars not only performed the GCI role, but also had a longer early warning range than the Mk. I and Mk. II installations. It was at this point that the Mark III began to have a significant influence on the ROTOR program. GCI radars had previously been located inland for two reasons. One was that their range
16274-445: The indigenous inhabitants of South Africa. Conflicts with Dutch settlers began in the 17th century and continued for centuries. Initial encounters between Dutch coloniers and Khoikhoi were peaceful, but tensions arose over land and resources. The Khoikhoi resisted Dutch expansion, leading to skirmishes and battles. The eastward expansion of Dutch colonists ushered in a series of wars with the southwesterly migrating Xhosa tribe, known as
16432-520: The interceptions to be handled from two Master Control Centers, with the MRSs now reduced to backup. Within the government, opinion was that Plan Ahead was itself facing a threat that appeared to render it useless. In this case, it was the introduction of the intermediate range ballistic missile (IRBM). IRBMs based in East Germany would hit the UK in about 15 minutes, potentially with no warning as
16590-558: The interior started the Mineral Revolution and increased economic growth and immigration. This intensified British subjugation of the indigenous people. The struggle to control these important economic resources was a factor in relations between Europeans and the indigenous population and also between the Boers and the British. On 16 May 1876, President Thomas François Burgers of the South African Republic declared war against
16748-422: The introduction of new wide-bandwidth low-noise crystal detectors . In 1950, the TRE combined these crystal detectors with new electronics and produced a microwave-frequency receiver that added 10 dB of signal-to-noise ratio , slightly more than three times the sensitivity of previous designs. The radar equation is based on the 4th root of received energy, meaning that three times the energy results in about
16906-563: The introduction of the hydrogen bomb upset the layout of the ROTOR system and led to the 1958 Plan, by the mid-1950s concerns over the carcinotron were growing. The initial response was released in January 1959 as Plan Ahead. Plan Ahead was similar to the 1958 Plan in general concept and network layout, but used the new Type 84 and Type 85 radars which had even longer effective range and were much more resistant to jamming. The network would be linked together using new computer systems to allow all of
17064-610: The national vote fall below 50% for the first time since the end of Apartheid, though it remained the single largest party in the South African Parliament. President Ramaphosa announced a national unity government , the first since the Cabinet of Nelson Mandela , and entered a deal with the Democratic Alliance , the previous main opposition party, and other minor parties. Ramaphosa was reelected for
17222-467: The nature of the defence, as a single bomber escaping interception was capable of causing catastrophic damage. Meanwhile, the introduction of the carcinotron radar jammer appeared to make such attacks much more likely to succeed. This led to plans to replace the Type 80s even before they were fully installed, relying on a much smaller network known as Linesman/Mediator with only three main sites. Two Type 80s were retained in this network for coverage over
17380-800: The network that would not receive the Type 85 and retain their Type 80s, and those were to be upgraded with the HF200. As part of this program, HF200's were eventually installed two-each at RAF Boulmer , RAF Saxa Vord , RAF Staxton Wold and three at RAF Bishops Court and RAF Neatishead . Additional units were sent to the 280 Signals Unit on RAF Cape Gata and RAF Troodos in Cyprus and another at RAF Bukit Gombak in Singapore . Foreign sales followed, three to Finland , eight to Sweden , ten to Iran , four to South Africa , one to India and three to Burma . Westinghouse Electric also purchased eight units for
17538-664: The north of the Cape Peninsula is bounded on the west by the Atlantic Ocean and the first row of north–south running Cape Fold Mountains to the east. The Cape Fold Mountains peter out at about the 32° S line of latitude, after which the Great Escarpment bounds the coastal plain. The most southerly portion of this coastal belt is known as the Swartland and Malmesbury Plain, which is an important wheat growing region, relying on winter rains. The region further north
17696-703: The north of the Swartberg range up to the Great Escarpment is the lowland part of the Great Karoo, which is climatically and botanically almost indistinguishable from the Karoo above the Great Escarpment. The narrow coastal strip between the Outeniqua and Langeberg ranges and the ocean has a moderately high year-round rainfall, which is known as the Garden Route . It is famous for the most extensive areas of forests in South Africa (a generally forest-poor country). In
17854-677: The northeast, consists of the Limpopo Lowveld, which merges into the Mpumalanga Lowveld, below the Mpumalanga Drakensberg (the eastern portion of the Great Escarpment). This is hotter, drier and less intensely cultivated than the Highveld above the escarpment. The Kruger National Park , located in the provinces of Limpopo and Mpumalanga in north-eastern South Africa, occupies a large portion of
18012-695: The obstacles were the presence of the independent states of the Boers, and the Zululand army. The Zulu nation defeated the British at the Battle of Isandlwana . Eventually Zululand lost the war, resulting in the termination of the Zulu nation's independence. The Boer republics successfully resisted British encroachments during the First Boer War (1880–1881) using guerrilla warfare tactics, which were well-suited to local conditions. The British returned with greater numbers, more experience, and new strategy in
18170-838: The organisation in 1961 and rejoined it in 1994. Despite opposition to apartheid both within and outside the country, the government legislated for a continuation of apartheid. The security forces cracked down on internal dissent, and violence became widespread, with anti-apartheid organisations such as the African National Congress (ANC), the Azanian People's Organisation , and the Pan-Africanist Congress carrying out guerrilla warfare and urban sabotage. The three rival resistance movements also engaged in occasional inter-factional clashes as they jockeyed for domestic influence. Apartheid became increasingly controversial, and several countries began to boycott business with
18328-542: The overall air defence picture. They had already given up on the concept of a close defence based on anti-aircraft guns and handed the SAM mission from the Army to the Air Force to be integrated into their interceptor operations. Now they were questioning the entire idea of widespread defence and increasingly seeing any system purely as a way to ensure the survival of the V bomber force. In keeping with this mission, by April 1955
18486-404: The overall status and wellbeing of the country, for example with regards to water resources . Speedy environmental changes are resulting in clear effects on the community and environmental level in different ways and aspects, starting with air quality, to temperature and weather patterns, reaching out to food security and disease burden. According to computer-generated climate modelling produced by
18644-682: The ownership of land by blacks; at that stage they controlled only 7% of the country. The amount of land reserved for indigenous peoples was later marginally increased. In 1931, the union became fully sovereign from the United Kingdom with the passage of the Statute of Westminster , which abolished the last powers of the Parliament of the United Kingdom to legislate in the country. Only three other African countries—Liberia, Ethiopia, and Egypt—had been independent prior to that point. In 1934,
18802-479: The plans had changed with the removal of two of the Mark III stations, at RAF Calvo and RAF Charmy Down . Now the remaining seventeen Mark III stations were expected to be operational in March 1958. In April 1956, the same month ROTOR I was declared fully operational, the new "1958 Plan" was released. ROTOR II and III disappeared, along with another two stations at RAF Hope Cove and RAF St. Twynnells . This left
18960-573: The present-day Groot River , in May 1488. On his return he saw the cape, which he named Cabo das Tormentas ('Cape of Storms'). King John II renamed the point Cabo da Boa Esperança , or Cape of Good Hope , as it led to the riches of the East Indies . Dias' feat of navigation was immortalised in Luís de Camões ' 1572 epic poem Os Lusíadas . By the early 17th century, Portugal's maritime power
19118-691: The presidency, National Director of Public Prosecutions Shaun Abrahams announced that Zuma would again face prosecution on 16 criminal charges – 12 charges of fraud, two of corruption, and one each of racketeering and money laundering, just as in the 2006 indictment. A warrant was issued for his arrest in February 2020 after he failed to appear in court. In 2021 he was found guilty of contempt of court and sentenced to 15 months' imprisonment. In response, supporters of Zuma engaged in protests which led to riots, looting, vandalism and widespread violence, leaving 354 people dead. South Africa has been undergoing
19276-593: The proposal. Elizabeth II lost the title Queen of South Africa , and the last Governor-General , Charles Robberts Swart , became state president . As a concession to the Westminster system , the appointment of the president remained by parliament and was virtually powerless until P. W. Botha 's Constitution Act of 1983 , which eliminated the office of prime minister and instated a unique "strong presidency" responsible to parliament . Pressured by other Commonwealth of Nations countries, South Africa withdrew from
19434-404: The proposed solutions has been to pass legislation, such as the pending Hate Crimes and Hate Speech Bill , to uphold South Africa's ban on racism and commitment to equality. On 14 February 2018, Jacob Zuma resigned the presidency. Since 15 February, ANC president Cyril Ramaphosa has been President of South Africa. On 16 March 2018, just over a month after President Jacob Zuma resigned from
19592-481: The radar station, the signal would be picked up in the radar antenna's side lobes , until the entire display was filled with noise and nothing could be tracked anywhere. It appeared that the decade-long effort to provide radar coverage for the UK was being rendered useless at a stroke. Through the same period, changes in the strategic environment were leading to questions about the ultimate role of defensive operations. Early post-war thinking treated nuclear weapons in
19750-466: The radars in their area. Phase I was to be completed by the end of 1952, or 1953 at the latest. ROTOR Phase II would replace the early warning portions of the network with a dramatically more powerful Microwave Early Warning (MEW) radar, which would push the detection range out and give the operators more time to deal with aircraft that were now expected to be jet powered. It would also mean fewer stations would be needed to provide complete coverage, and
19908-484: The range of the Type 7. That meant it could potentially fill the OR2046 GCI role as well. This would benefit from even higher angular resolution, but much more important was its ability to scan at higher altitudes so that the area above the station would be at least partially covered. Faster scanning rates would also be desirable. This could be accomplished through the design of a somewhat modified antenna, which became
20066-484: The region over 100,000 years ago. The first known people were the indigenous Khoisan , and Bantu-speaking peoples who expanded from West and Central Africa later settled in the region 2,000 to 1,000 years ago. In the north, the Kingdom of Mapungubwe formed in the 13th century. In 1652, the Dutch established the first European settlement at Table Bay , and in 1795 and 1806 , the British occupied it. The Mfecane ,
20224-477: The requirements of OR2047, yet do so years earlier than the MEW. This led to changes in the ROTOR plans so that these new radars, referred to within the plans as Stage IA, or Stage 1 + 1 ⁄ 2 , would be deployed as part of ROTOR Phase II. Not only would the system be ready earlier than MEW, it would eliminate many of the existing WWII-era stations saving £1.6 million in installation costs, and another £1.5 million
20382-540: The ruins are thought to be created by the Bakone , a Northern Sotho people. Around 1220, in the Limpopo - Shashe Basin, the elite of K2 moved to settle the flat-topped summit of Mapungubwe Hill, with the population settling below. Rainmaking was crucial to the development of sacral kingship . By 1250, the capital had a population of 5000 and the state covered 30,000 km² (11,500 square miles), growing wealthy through
20540-424: The shrunken 1958 Plan was declared complete, with eight GCI stations having been converted to MRSs. This had already allowed the six Sector Operations Centers and a number of other facilities to be closed. The only remaining work was to re-arrange the consoles in the interception offices, which would be carried out until 1962. The Air Council agreed that no further work should be done on the existing network. Just as
20698-426: The side-effect of greatly reducing the total complexity of the reporting and control system. The total number of stations was reduced from 37 of ROTOR III to 28, many of the operational centres would not be needed, and 3,000 full-time manpower requirements could be removed while at the same time expanding from a 2-shift to 3-shift round-the-clock operation. The fact that ROTOR only operated during daylight hours had been
20856-546: The south-west corner of the country, the Cape Peninsula forms the southernmost tip of the coastal strip which borders the Atlantic Ocean and ultimately terminates at the country's border with Namibia at the Orange River . The Cape Peninsula has a Mediterranean climate , making it and its immediate surrounds the only portion of Sub-Saharan Africa which receives most of its rainfall in winter. The coastal belt to
21014-463: The support framework and mounting system. As the second batch of stations neared their construction start dates, there was not enough time to get the new magnetron into production. Adopting only the new waveguide, these systems became the second production Mark I design. A greatly strengthened antenna and mounting design intended for all of the northern bases became the Mark II. As early as 1950,
21172-444: The teens. The first of the units would be purely experimental and would be installed at RAF Bard Hill , the following six units were expected to be installed through 1953 and be operational in mid-1954. This set of quickly installed systems was carried out under "Operation ROTOR 2". The design's improved resolution allowed it to distinguish between closely spaced targets at 95 nautical miles (176 km; 109 mi), well over twice
21330-547: The victims were South African citizens. In a 2006 survey, the South African Migration Project concluded that South Africans are more opposed to immigration than any other national group. The UN High Commissioner for Refugees in 2008 reported that over 200,000 refugees applied for asylum in South Africa, almost four times as many as the year before. These people were mainly from Zimbabwe , though many also come from Burundi , Democratic Republic of
21488-673: The war. Starting in 1943, with the threat of German air attack waning, the Dowding system began to wind down operations. At the end of the war this process accelerated, as it was believed another war was at least a decade off. To address the UK's needs during this expected interwar period, in 1945 Group Captain J. Cherry authored "A Memorandum on the Raid Reporting and Control Aspects of the United Kingdom Air Defense Organization", better known as
21646-438: The wars, Dutch-descendant Boer farmers fled into cities from the devastated Transvaal and Orange Free State territories to become the class of the white urban poor. Anti-British policies among white South Africans focused on independence. During the Dutch and British colonial years, racial segregation was mostly informal, though some legislation was enacted to control the settlement and movement of indigenous people, including
21804-468: The wine in South Africa and is known for its wind, which blows intermittently almost all year. The severity of this wind made passing around the Cape of Good Hope particularly treacherous for sailors, causing many shipwrecks. Further east on the south coast, rainfall is distributed more evenly throughout the year, producing a green landscape. The annual rainfall increases south of the Lowveld, especially near
21962-410: The world. Archaeologists have recovered extensive fossil remains from a series of caves in Gauteng Province. The area, a UNESCO World Heritage Site , has been branded "the Cradle of Humankind ". The sites include Sterkfontein , one of the richest sites for hominin fossils in the world, as well as Swartkrans , Gondolin Cave , Kromdraai , Cooper's Cave and Malapa . Raymond Dart identified
22120-431: The wrong position relative to the receiver above it, but this was corrected by repeatedly moving it and testing it. The only issue requiring modifications to the basic design was a minor change to the oil system in the 8 foot (2.4 m) diameter bearing that supported the antenna. This became the pattern for following systems, and the original order of seven units was installed to this new standard. The Trimingham system
22278-413: The year. As the parts arrived and lessons learned from their installation, the design was further modified. By the end of the year, the final design of the Type 80 was released. At the same time, the order was increased to eleven units. The first true production unit began installation at RAF Trimingham in early 1954, taking much of the year to complete. The transmitter antenna was initially installed in
22436-631: Was a highlight of the exercise. But Ardent also demonstrated that ROTOR's limited coverage over northern Scotland provided a "back door" route that allowed bombers to elude the fighters. Concerns expressed by the Admiralty that this route could be used to mine western ports led an order for an additional eight Stage IA radars in February 1953. These would be placed in Scotland, the Shetland Islands, and Northern Ireland. A new sector operations centre in Inverness would handle traffic in this area. This expansion became known as ROTOR Phase III. This change results in some confusing terminology. Originally, ROTOR
22594-411: Was among the most powerful radars of its era; the Mark III versions had a detection range against bomber-sized targets of at least 200 nautical miles (370 km; 230 mi) whilst having enough resolution to directly guide interceptor aircraft from its radar displays. Key to the success of the Mark III was a new 2.5 MW cavity magnetron developed at Decca. With the completion of development of
22752-436: Was arranged to be taken over by the Royal Canadian Air Force (RCAF) for delivery in the summer of 1955. This later unit would be used by the 1 Canadian Air Division to control the airspace used by the Second Tactical Air Force . By October, four of the Type 80s were in service, late but well on the way to completing the original Phase IA. A fifth Mk. I system in the UK, as well as the RCAF Mk. I in Metz, were operational by
22910-435: Was demonstrated to NATO officials in October 1954. This was part of an effort to develop a NATO-wide air warning system that would eventually emerge as the NATO Air Defence Ground Environment (NADGE). Trimingham was handed over operationally to the RAF in February 1955, about six months later than initially expected, but still well over two years before the original ROTOR plans called for the MEW's to be installed. ROTOR I
23068-485: Was effectively 50 by 8 feet (15.2 m × 2.4 m), with a beam-width of 1 ⁄ 2 degree. The first example, known as Green Garlic, was operational on 18 February 1951, and a few days later it demonstrated its ability to detect de Havilland Mosquito and Gloster Meteor aircraft at ranges of 200 nautical miles (370 km; 230 mi), and track them continually at 160 nautical miles (300 km; 180 mi) while flying at 25,000 feet (7.6 km),
23226-439: Was fought in 1879 between the British and the Zulu Kingdom . Following Lord Carnarvon 's successful introduction of federation in Canada , it was thought that similar political effort, coupled with military campaigns, might succeed with the African kingdoms, tribal areas and Boer republics in South Africa. In 1874, Henry Bartle Frere was sent to South Africa as the British High Commissioner to bring such plans into being. Among
23384-406: Was in a fairly complete form. It primarily used the Chain Home radars for early warning, supplanted by Chain Home Low and a handful of other special-purpose early warning designs. For fighter direction, or ground controlled interception (GCI) as it was known, the primary system was the somewhat more modern AMES Type 7 , with smaller numbers of the advanced AMES Type 14 entering service late in
23542-426: Was lower. This meant the design would have less range than the Type 80 even though it was otherwise similar. One of the other side-effects of the original improper installation of the transmitter at Trimmingham was the observation that the vertical angle of the coverage pattern could be raised by moving the transmitter. This seemed to eliminate the need for the separate GCI radar, and any given radar could be made into
23700-419: Was not completed by the end of 1953 as expected, as the upgraded Type 7's proved to be rather problematic and it was not until early 1955 that the systems were all modified to correct the problems. These delays closely matched those of the Type 80 installations. In July 1955, the ROTOR I system was declared "complete to all intents and purposes". Following Trimmingham, another five systems were to come online at
23858-444: Was previously rare, increased. The government struggled to achieve the monetary and fiscal discipline to ensure both redistribution of wealth and economic growth. The United Nations Human Development Index rose steadily until the mid-1990s then fell from 1995 to 2005 before recovering its 1995 peak in 2013. The fall is in large part attributable to the South African HIV/AIDS pandemic which saw South African life expectancy fall from
24016-519: Was received by the convention on 7 June 2006. The country is ranked sixth out of the world's seventeen megadiverse countries . Ecotourism in South Africa has become more prevalent in recent years, as a possible method of maintaining and improving biodiversity. Numerous mammals are found in the Bushveld including lions, African leopards , South African cheetahs , southern white rhinos , blue wildebeest , kudus , impalas , hyenas , hippopotamuses and South African giraffes . A significant extent of
24174-405: Was relatively short, so they needed to be spread out geographically so their coverage overlapped in the defended area. Secondly, in order to reduce local reflections, the Type 7's had to be installed in natural depressions, typically bowl-shaped valleys. In the case of the Mark III, neither of these apply; the range of the system was so great that it could cover the entire inland area even if sited on
24332-464: Was south of the furthest point reached in 1485 by his predecessor, the Portuguese navigator Diogo Cão ( Cape Cross , north of the bay). Dias continued down the western coast of southern Africa. After 8 January 1488, prevented by storms from proceeding along the coast, he sailed out of sight of land and passed the southernmost point of Africa without seeing it. He reached as far up the eastern coast of Africa as, what he called, Rio do Infante , probably
24490-415: Was starting to decline, and English and Dutch merchants competed to oust Portugal from its lucrative monopoly on the spice trade . Representatives of the British East India Company sporadically called at the cape in search of provisions as early as 1601 but later came to favour Ascension Island and Saint Helena as alternative ports of refuge. Dutch interest was aroused after 1647, when two employees of
24648-418: Was straightforward, the main effort would be the development of a suitable antenna with a very narrow vertical beamwidth that would provide accurate measures of the vertical angle. Around this time the Ministry of Defence (MoD) reached the same conclusions about their existing height-finders, and began looking for options. Decca decided to risk the development of the system as a private venture. In addition to
24806-420: Was the Xhosa people , whose language incorporates certain linguistic traits from the earlier Khoisan people. The Xhosa reached the Great Fish River , in today's Eastern Cape Province. As they migrated, these larger Iron Age populations displaced or assimilated earlier peoples. In Mpumalanga Province, several stone circles have been found along with a stone arrangement that has been named Adam's Calendar , and
24964-418: Was to be in two phases, describing both the expansion of the network and its upgrading with the new radars. Now the Stage IA radar would be used with ROTOR Phase II and III, while the original Stage II radar was no longer associated with any of ROTOR's phases. In January 1953, Bard Hill had been selected as the site for a prototype of the production design. Construction of the system at was carried out through
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