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137-625: The name comes from a species of cactus on the island, the Turk's cap cactus ( Melocactus intortus ), which has a distinctive cap, reminiscent of an Ottoman fez . In addition, this interpretation of the name received a reaction in the Turkish press on the grounds that it was anachronism . Fez began to be used by the Ottoman Turks in the 19th century, and the "Turk" in the island's name dates back to very old times. The Lucayan people were

274-453: A pericarpel . Tissue derived from the petals and sepals continues the pericarpel, forming a composite tube—the whole may be called a floral tube, although strictly speaking only the part furthest from the base is floral in origin. The outside of the tubular structure often has areoles that produce wool and spines. Typically, the tube also has small scale-like bracts , which gradually change into sepal-like and then petal-like structures, so

411-464: A cactus. Stem shapes vary considerably among cacti. The cylindrical shape of columnar cacti and the spherical shape of globular cacti produce a low surface area-to-volume ratio, thus reducing water loss, as well as minimizing the heating effects of sunlight. The ribbed or fluted stems of many cacti allow the stem to shrink during periods of drought and then swell as it fills with water during periods of availability. A mature saguaro ( Carnegiea gigantea )

548-516: A clear sandy bottom would not have been possible had Columbus sailed from the islands of the Bahamas. In addition, the latitudes recorded in Columbus' diary place the landfall island at 90 nautical miles (100 mi; 170 km) from Hispaniola , too close for the Bahamas, but almost exactly the distance from Grand Turk. On the contrary, historian Gregory McIntosh has concluded that Grand Turk

685-547: A cluster may share a common root. Other cacti have a quite different appearance. In tropical regions, some grow as forest climbers and epiphytes . Their stems are typically flattened and almost leaf-like in appearance, with few or even no spines. Climbing cacti can be very large; a specimen of Hylocereus was reported as 100 meters (330 ft) long from root to the most distant stem. Epiphytic cacti, such as species of Rhipsalis or Schlumbergera , often hang downwards, forming dense clumps where they grow in trees high above

822-420: A complex return pattern. Since the pattern depended on the atmospherics between the transmitter and receiver, the received pattern was different for the two stations. One might receive a two-bounce skywave from one station at the same time as a three-bounce wave from another, making interpretation of the display quite difficult. Although LORAN deliberately used the same display as Gee in order to share equipment,

959-444: A continuous signal, as in the case of Decca, the signal would be in the form of pulses. These would be used to make a rough fix using the same technique as Gee or LORAN, positively identifying the lane. The only problem from a development standpoint would be selecting frequencies that allowed reasonably accurate pulse envelopes while still having measurable waveforms within the pulses, as well as developing displays capable of showing both

1096-464: A continuous supply of CO 2 during photosynthesis means the stomata must be open, so water vapor is continuously being lost. Plants using the C 3 mechanism lose as much as 97% of the water taken up through their roots in this way. A further problem is that as temperatures rise, the enzyme that captures CO 2 starts to capture more and more oxygen instead, reducing the efficiency of photosynthesis by up to 25%. Crassulacean acid metabolism (CAM)

1233-448: A contract to develop a system called "Cytac", which used the same basic techniques as LF LORAN, but included considerable automation to handle the timing internally without operator intervention. This proved to be extremely successful, with test-runs placing the aircraft within 10 yards of the target. As the mission changed from short-range tactical bombing to over-the-pole nuclear delivery, the (newly formed) U.S. Air Force lost interest in

1370-411: A drought. The concentration of salts in the root cells of cacti is relatively high. All these adaptations enable cacti to absorb water rapidly during periods of brief or light rainfall. Thus, Ferocactus cylindraceus reportedly can take up a significant amount of water within 12 hours from as little as 7 mm (0.3 in) of rainfall, becoming fully hydrated in a few days. Although in most cacti,

1507-558: A family of the order Caryophyllales comprising about 127 genera with some 1,750 known species. The word cactus derives, through Latin, from the Ancient Greek word κάκτος ( káktos ), a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. They are native to the Americas, ranging from Patagonia in the south to parts of western Canada in

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1644-462: A fixed distance to either side. Decca referred to these radial areas as "lanes", and used a mechanical system to keep track of which one the receiver was in. By combining the two concepts, envelope timing and phase comparison, both of these problems could be eliminated. Since phase comparison is generally more accurate at low frequencies due to details of the electronics, taking accurate fixes would be based on this technique. But instead of broadcasting

1781-415: A greater volume than the body. Taproots may aid in stabilizing the larger columnar cacti. Climbing, creeping and epiphytic cacti may have only adventitious roots , produced along the stems where these come into contact with a rooting medium. Like their spines, cactus flowers are variable. Typically, the ovary is surrounded by material derived from stem or receptacle tissue, forming a structure called

1918-415: A high surface area-to-volume ratio, at maturity they contain little or no water, being composed of fibers made up of dead cells. Spines provide protection from herbivores and camouflage in some species, and assist in water conservation in several ways. They trap air near the surface of the cactus, creating a moister layer that reduces evaporation and transpiration . They can provide some shade, which lowers

2055-495: A hyperbolic system is a function of the baseline distance, so if the stations could be spread out, the system would become more accurate, so fewer stations would be needed for any desired navigational task. A test system was first attempted on 10 April 1943 between the LORAN stations at Fenwick and Bonavista, 1,100 miles (1,800 km) away. This test demonstrated accuracy of ½ mile, significantly better than normal LORAN. This led to

2192-442: A kind of highly reduced branch. Areoles are an identifying feature of cacti. As well as spines, areoles give rise to flowers , which are usually tubular and multipetaled. Many cacti have short growing seasons and long dormancies and are able to react quickly to any rainfall, helped by an extensive but relatively shallow root system that quickly absorbs any water reaching the ground surface. Cactus stems are often ribbed or fluted with

2329-624: A long mission. This reduced fuel load allowed the bombload to be increased. By the end of World War II there were 72 LORAN stations, with over 75,000 receivers in use. Additional chains in the Pacific were added in the post-war era. A spurt in construction followed the opening of the Korean War , including new chains in Japan and one at Busan , Korea. Chains were also installed in China, prior to

2466-527: A major staging ground for German U-boats and capital ships. The enormous distances and lack of useful navigation points in the Pacific Ocean led to widespread use of LORAN for both ships and aircraft during the Pacific War . In particular, the accuracy offered by LORAN allowed aircraft to reduce the amount of extra fuel they would otherwise have to carry to ensure they could find their base after

2603-471: A maximum range of 300–500 miles (480–800 km) for high-flying aircraft. This led to the "Precision Navigational Equipment for Guiding Airplanes" specification, which was sent back to the Microwave Committee and formed up as "Project 3". Orders for initial systems were sent out at a follow-up meeting on 20 December 1940. Edward George Bowen , developer of the first airborne radar systems ,

2740-648: A measurement. Ideally, perfectly formed rectangular blips would be displayed on the CRT, whose leading edge could be compared with a high degree of accuracy. In practice, the transmitters cannot turn on and off instantly, and due to a variety of factors the resulting blips are spread out in time, forming an envelope . The sharpness of the envelope is a function of the frequency, meaning the lower-frequency systems like LORAN will always have longer envelopes with less well-defined start and stop points, and thus generally have less accuracy than higher-frequency systems like Gee. There

2877-418: A normal shoot, nodes bearing leaves or flowers would be separated by lengths of stem (internodes). In an areole, the nodes are so close together, they form a single structure. The areole may be circular, elongated into an oval shape, or even separated into two parts; the two parts may be visibly connected in some way (e.g. by a groove in the stem) or appear entirely separate (a dimorphic areole). The part nearer

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3014-466: A number indicating the frequency band, a letter for the pulse repetition frequency, and a number for the station within the chain. For instance, the three stations on the Hawaiian Islands were arranged as two pairs 2L 0 and 2L 1. This indicated that they were on channel 2 (1.85 MHz), used the "L"ow repetition rate (25 Hz), and that two of the stations were on the base repetition rate, while

3151-492: A number of ribs which corresponds to a number in the Fibonacci numbers (2, 3, 5, 8, 13, 21, 34 etc.). This allows them to expand and contract easily for quick water absorption after rain, followed by retention over long drought periods. Like other succulent plants, most cacti employ a special mechanism called " crassulacean acid metabolism " (CAM) as part of photosynthesis. Transpiration , during which carbon dioxide enters

3288-466: A particular plant is an example of, say, Mammillaria mammillaris , they should be able to compare it with the type specimen to which this name is permanently attached. Type specimens are normally prepared by compression and drying, after which they are stored in herbaria to act as definitive references. However, cacti are very difficult to preserve in this way; they have evolved to resist drying and their bodies do not easily compress. A further difficulty

3425-598: A second round of tests in late 1943, this time using four stations, Montauk, East Brewster, Massachusetts , Gooseberry Falls, Minnesota , and Key West, Florida . Extensive evaluation flights revealed an average error of 1–2 miles (1.6–3.2 km). The nighttime mode of operation was a perfect fit for RAF Bomber Command . The four test stations were dismantled and shipped across the Atlantic, and re-installed to form two chains, Aberdeen - Bizerta , and Oran - Benghazi . Known as Skywave-Synchronized LORAN , or SS LORAN ,

3562-429: A selected part of the signal was visible on the screen. Turning to sweep speed 4 did not change the timing, but instead superimposed the signals on a single trace so final tuning could take place, using the gain and amplifier balance controls. The goal was to perfectly align the two traces. At that point, measurement starts. The operator switches to sweep speed 5, which returns to a display with two separated traces, with

3699-446: A series of "blips" on the display. By measuring the distance between them, the delay between the two signals can be calculated. For instance, a receiver might measure the distance between the two blips to represent a delay of 0.5 ms. This implies that the difference in the distance to the two stations is 150 km. There are an infinite number of locations where that delay could be measured – 75 km from one station and 225 from

3836-419: A series of sharp spikes (blips). As the signal was repeating, these spikes appeared many times across the width of the display. Because the display was set to sweep at the pulse repetition rate of the selected station pair, other stations in the area, at different repetition rates, would move across the display while the selected one would remain stationary. Using the "left-right" switch, the operator would move

3973-655: A specimen, which, according to David Hunt , ensured he "left a trail of nomenclatural chaos that will probably vex cactus taxonomists for centuries." In 1984, it was decided that the Cactaceae Section of the International Organization for Succulent Plant Study should set up a working party, now called the International Cactaceae Systematics Group (ICSG), to produce consensus classifications down to

4110-527: A viable technology, which is already being pursued by other countries. At a 1 October 1940 meeting of the U.S. Army Signal Corps' Technical Committee, Alfred Loomis , chair of the Microwave Committee of the National Defense Research Committee , proposed building a hyperbolic navigation system. He predicted that such a system could provide an accuracy of at least 1,000 feet (300 m) at a range of 200 miles (320 km), and

4247-433: Is a mechanism adopted by cacti and other succulents to avoid the problems of the C 3 mechanism. In full CAM, the stomata open only at night, when temperatures and water loss are lowest. CO 2 enters the plant and is captured in the form of organic acids stored inside cells (in vacuoles ). The stomata remain closed throughout the day, and photosynthesis uses only this stored CO 2 . CAM uses water much more efficiently at

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4384-448: Is an entirely different way to accomplish the same timing measurement, not by comparing the timing of the pulse envelopes, but timing the phase of the signals. This is actually quite easy to perform using simple electronics and can be displayed directly using a simple mechanical pointer. The trick to such a system is to ensure the primary and secondary stations are phase-coherent, a complex proposition during World War II . But by isolating

4521-401: Is close to the ancestral species from which all cacti evolved) does have long-lasting leaves, which are, however, thickened and succulent in many species. Other species of cactus with long-lasting leaves, such as the opuntioid Pereskiopsis , also have succulent leaves. A key issue in retaining water is the ratio of surface area to volume. Water loss is proportional to surface area, whereas

4658-546: Is considered close to the ancestral species from which all cacti evolved. In tropical regions, other cacti grow as forest climbers and epiphytes (plants that grow on trees). Their stems are typically flattened, almost leaf-like in appearance, with fewer or even no spines, such as the well-known Christmas cactus or Thanksgiving cactus (in the genus Schlumbergera ). Cacti have a variety of uses: many species are used as ornamental plants, others are grown for fodder or forage, and others for food (particularly their fruit). Cochineal

4795-482: Is derived through Latin from the Ancient Greek κάκτος ( kaktos ), a name used by Theophrastus for a spiny plant, which may have been the cardoon ( Cynara cardunculus ). Later botanists, such as Philip Miller in 1754, divided cacti into several genera, which, in 1789, Antoine Laurent de Jussieu placed in his newly created family Cactaceae. By the early 20th century, botanists came to feel Linnaeus's name Cactus had become so confused as to its meaning (was it

4932-835: Is particularly true of tree-living cacti, such as Rhipsalis and Schlumbergera , but also of some ground-living cacti, such as Ariocarpus . The spines of cacti are often useful in identification, since they vary greatly between species in number, color, size, shape and hardness, as well as in whether all the spines produced by an areole are similar or whether they are of distinct kinds. Most spines are straight or at most slightly curved, and are described as hair-like, bristle-like, needle-like or awl-like, depending on their length and thickness. Some cacti have flattened spines (e.g. Sclerocactus papyracanthus ). Other cacti have hooked spines. Sometimes, one or more central spines are hooked, while outer spines are straight (e.g., Mammillaria rekoi ). In addition to normal-length spines, members of

5069-479: Is present in Pereskia species. By studying the ratio of C to C incorporated into a plant—its isotopic signature —it is possible to deduce how much CO 2 is taken up at night and how much in the daytime. Using this approach, most of the Pereskia species investigated exhibit some degree of CAM-cycling, suggesting this ability was present in the ancestor of all cacti. Pereskia leaves are claimed to only have

5206-401: Is repeated for setting 6 at 50 microseconds, and again at setting 7 at 500 microseconds. The difference as measured at each of these settings is then added up to produce the total delay between the two signals. This entire procedure was then repeated for a second primary-secondary set, often the second set of the same chain but not always. Receiver units improved greatly over time. The AN/APN-4

5343-557: Is said to be able to absorb as much as 200 U.S. gallons (760 L; 170 imp gal) of water during a rainstorm. A few species differ significantly in appearance from most of the family. At least superficially, plants of the genera Leuenbergeria , Rhodocactus and Pereskia resemble other trees and shrubs growing around them. They have persistent leaves, and when older, bark-covered stems. Their areoles identify them as cacti, and in spite of their appearance, they, too, have many adaptations for water conservation . Leuenbergeria

5480-416: Is said to be able to absorb as much as 200 U.S. gallons (760 L; 170 imp gal) of water during a rainstorm. The outer layer of the stem usually has a tough cuticle , reinforced with waxy layers, which reduce water loss. These layers are responsible for the grayish or bluish tinge to the stem color of many cacti. The stems of most cacti have adaptations to allow them to conduct photosynthesis in

5617-469: Is that many cacti were given names by growers and horticulturalists rather than botanists; as a result, the provisions of the International Code of Nomenclature for algae, fungi, and plants (which governs the names of cacti, as well as other plants) were often ignored. Curt Backeberg , in particular, is said to have named or renamed 1,200 species without one of his names ever being attached to

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5754-724: Is the product of an insect that lives on some cacti. Many succulent plants in both the Old and New World – such as some Euphorbiaceae (euphorbias) – are also spiny stem succulents and because of this are sometimes incorrectly referred to as "cactus". The 1,500 to 1,800 species of cacti mostly fall into one of two groups of "core cacti": opuntias (subfamily Opuntioideae ) and "cactoids" (subfamily Cactoideae ). Most members of these two groups are easily recognizable as cacti. They have fleshy succulent stems that are major organs of photosynthesis . They have absent, small, or transient leaves . They have flowers with ovaries that lie below

5891-514: The Admiralty List of Radio Signals . Hyperbolic navigation systems can be divided into two main classes, those that calculate the time difference between two radio pulses, and those that compare the phase difference between two continuous signals. To illustrate the basic concept, this section will consider the pulse method only. Consider two radio transmitters located at a distance of 300 kilometers (190 mi) from each other, which means

6028-626: The Bahamas or Grand Cayman . Grand Turk Lighthouse was erected in 1852 near northern end of the island. The 60 ft (18 m) lighthouse was designed by Alexander Gordon and built by Chance Brothers in England. It was shipped in pieces and assembled on Grand Turk. Grand Turk has been put forward as the possible landfall island of Christopher Columbus during his first voyage to the New World in 1492. San Salvador Island or Samana Cay in

6165-402: The C 3 mechanism with CAM restricted to stems. More recent studies show that "it is highly unlikely that significant carbon assimilation occurs in the stem"; Pereskia species are described as having "C 3 with inducible CAM." Leafless cacti carry out all their photosynthesis in the stem, using full CAM. As of February 2012 , it is not clear whether stem-based CAM evolved once only in

6302-702: The Friendship 7 is on display in Grand Turk at the entrance to the Grand Turk airport. In 1966 at least five Arcas (All-Purpose Rocket for Collecting Atmospheric Soundings) sounding rockets were launched from Grand Turk by the USA. Cactus See also Classification of the Cactaceae A cactus ( pl. : cacti , cactuses , or less commonly, cactus ) is a member of the plant family Cactaceae ( / k æ k ˈ t eɪ s i . iː , - ˌ aɪ / ),

6439-443: The monophyly of three of these subfamilies (not Pereskioideae), but have not supported all of the tribes or even genera below this level; indeed, a 2011 study found only 39% of the genera in the subfamily Cactoideae sampled in the research were monophyletic . Classification of the cacti currently remains uncertain and is likely to change. A 2005 study suggested the genus Pereskia as then circumscribed ( Pereskia sensu lato)

6576-441: The sepals and petals , often deeply sunken into a fleshy receptacle (the part of the stem from which the flower parts grow). All cacti have areoles —highly specialized short shoots with extremely short internodes that produce spines , normal shoots, and flowers. The remaining cacti fall into only two groups: three tree-like genera, Leuenbergeria , Pereskia and Rhodocactus (all formerly placed in Pereskia ), and

6713-484: The "columns" may be horizontal rather than vertical. Thus, Stenocereus eruca can be described as columnar even though it has stems growing along the ground, rooting at intervals. Cacti whose stems are even smaller may be described as globular (or globose). They consist of shorter, more ball-shaped stems than columnar cacti. Globular cacti may be solitary, such as Ferocactus latispinus , or their stems may form clusters that can create large mounds. All or some stems in

6850-513: The Atlantic and Caribbean transmitters on 31 December 1980. Several foreign chains in both the Pacific and Atlantic followed suit, and by 1985 most of the original chains were no longer operational. Japanese systems remained on the air longer, until 1991, serving their fishing fleet. Chinese systems were active into the 1990s before their replacement with more modern systems, and their nine chains were still listed as active in Volume 6 (2000 edition) of

6987-404: The Bahamas is traditionally identified with Guanahani , the site of Columbus' first landfall , but some believe that studies of Columbus' journals show that his descriptions of Guanahani much more closely fit Grand Turk than they do other candidates. Magnetic variations that caused misreadings in Columbus' compasses demonstrate that several of the recorded moorings using a rope-secured anchor to

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7124-470: The Project 3 team also found that Gee was almost identical to their own system in concept and desired performance. Unlike their system, Gee had largely completed development and was proceeding to production. The decision was made to abandon the current efforts, use Gee on their own aircraft, and re-develop their system for the long-range role instead. The decision to switch to the long-range role meant that

7261-542: The U.S. Coast Guard in 1958. At that time, the original LORAN became Loran-A or standard LORAN , and the new system became Loran-C . In spite of the greatly increased accuracy and ease-of-use of Loran-C, Loran-A remained in widespread use. This was due largely to two important factors. One was that the electronics needed to read a Loran-C signal were complex, and in the era of tube-based electronics, physically very large, generally fragile, and expensive. Further, as military ships and aircraft moved from Loran-A to Loran-C,

7398-695: The U.S. and Canadian east coast were installed through October, and the system was declared operational in early 1943. By the end of that year additional stations had been installed in Greenland , Iceland , the Faroe Islands and the Hebrides , offering continuous coverage across the North Atlantic. RAF Coastal Command had another station installed in Shetland , offering coverage over Norway,

7535-403: The absence of leaves. This is discussed further below under Metabolism . Many cacti have roots that spread out widely, but only penetrate a short distance into the soil. In one case, a young saguaro only 12 cm (4.7 in) tall had a root system with a diameter of 2 m (7 ft), but no more than 10 cm (4 in) deep. Cacti can also form new roots quickly when rain falls after

7672-413: The amount of water present is proportional to volume. Structures with a high surface area-to-volume ratio, such as thin leaves, necessarily lose water at a higher rate than structures with a low area-to-volume ratio, such as thickened stems. Spines , which are modified leaves, are present on even those cacti with true leaves, showing the evolution of spines preceded the loss of leaves. Although spines have

7809-496: The capabilities. Nevertheless, the three transmitters were re-installed in northern Canada and Alaska for experiments in polar navigation, and ran for three years until shutting down again in March 1950. These experiments demonstrated accuracy on the order of 0.15 microseconds, or about 50 metres (0.031 miles), a great advance over LORAN. Maximum usable range was 1,000 miles (1,600 km) over land and 1,500 miles (2,400 km) on

7946-408: The concept. Nevertheless, they continued experimentation with the equipment after adapting it to work on LF LORAN frequencies and renaming it "Cyclan", lowering accuracy compared to the original, but providing reasonable accuracy on the order of a mile at greatly increased distances. The Navy had also been experimenting with a similar concept during this period, but using a different method to extract

8083-600: The core cacti, or separately in the opuntias and cactoids; CAM is known to have evolved convergently many times. To carry out photosynthesis, cactus stems have undergone many adaptations. Early in their evolutionary history, the ancestors of modern cacti (other than Leuenbergeria species) developed stomata on their stems and began to delay developing bark. However, this alone was not sufficient; cacti with only these adaptations appear to do very little photosynthesis in their stems. Stems needed to develop structures similar to those normally found only in leaves. Immediately below

8220-523: The day, and 2 MHz at night. Initial tests were carried out in May 1944 between Chatham, Massachusetts , and Fernandina, Florida , and a second set between Hobe Sound, Florida , and Point Chinato, Puerto Rico , in December–January 1945–46. The system was not put into operation, due to a lack of suitable frequency allocations. LORAN was a simple system that compared the arrival times of pulses to make

8357-496: The diameter of the tube, while the J-scope presents this as the angle around the cathode ray tube 's face. This increases the amount of room on the scale by a factor of π for any given display size, improving accuracy. In spite of using the J-scope, and adopting the lower frequency change for more stability, the team found accurate measurements of range quite difficult. At the time, the procedure for generating sharp pulses of signals

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8494-669: The end into more than one stigma . The stamens usually arise from all over the inner surface of the upper part of the floral tube, although in some cacti, the stamens are produced in one or more distinct "series" in more specific areas of the inside of the floral tube. The flower as a whole is usually radially symmetrical ( actinomorphic ), but may be bilaterally symmetrical ( zygomorphic ) in some species. Flower colors range from white through yellow and red to magenta. All cacti have some adaptations to promote efficient water use. Most cacti— opuntias and cactoids —specialize in surviving in hot and dry environments (i.e. are xerophytes ), but

8631-495: The ends of stems, which are still growing and forming new areoles. In Pereskia , a genus close to the ancestor of cacti, areoles remain active for much longer; this is also the case in Opuntia and Neoraimondia . The great majority of cacti have no visible leaves ; photosynthesis takes place in the stems (which may be flattened and leaflike in some species). Exceptions occur in three (taxonomically, four) groups of cacti. All

8768-516: The expensive portions of the system at the few broadcast stations, the Decca Navigation System using this technique went active in 1944, offering accuracy similar to Gee but using low-cost mechanical displays which were also much easier to use. The downside to the phase comparison system is that it is not possible to know from a continuous wave signal, like Decca's, which part of the signal you are measuring. You could be comparing

8905-404: The first ancestors of modern cacti were already adapted to periods of intermittent drought. A small number of cactus species in the tribes Hylocereeae and Rhipsalideae have become adapted to life as climbers or epiphytes , often in tropical forests, where water conservation is less important. The absence of visible leaves is one of the most striking features of most cacti. Pereskia (which

9042-404: The first down range tracking facility of the U.S. Air Force's Eastern Range to have a Missile Impact Location System (MILS) target array to detect the splash down location of test missile nose cones. The next target arrays down range were located at 1,300 nmi (1,500 mi; 2,400 km) at Antigua and at 4,400 nmi (5,100 mi; 8,100 km) at Ascension Island . In addition to

9179-414: The first waveform from one station to the first from another, but the second waveform looks identical and the operator may line up those two waves instead. This leads to a problem where the operator can generate an accurate measurement, but the actual fix might be at a wide variety of locations. These locations are separated radially around the station, meaning a fix might be within a given radial direction or

9316-576: The genera Leuenbergeria , Pereskia and Rhodocactus , the branches are covered with leaves, so the species of these genera may not be recognized as cacti. In most other cacti, the branches are more typically cactus-like, bare of leaves and bark and covered with spines, as in Pachycereus pringlei or the larger opuntias . Some cacti may become tree-sized but without branches, such as larger specimens of Echinocactus platyacanthus . Cacti may also be described as shrubby , with several stems coming from

9453-880: The genus Mammillaria and outgrowths almost like leaves in Ariocarpus species. The stem may also be ribbed or fluted in shape. The prominence of these ribs depends on how much water the stem is storing: when full (up to 90% of the mass of a cactus may be water), the ribs may be almost invisible on the swollen stem, whereas when the cactus is short of water and the stems shrink, the ribs may be very visible. The stems of most cacti are some shade of green, often bluish or brownish green. Such stems contain chlorophyll and are able to carry out photosynthesis; they also have stomata (small structures that can open and close to allow passage of gases). Cactus stems are often visibly waxy. Areoles are structures unique to cacti. Although variable, they typically appear as woolly or hairy areas on

9590-529: The genus or the family?) that it should not be used as a genus name. The 1905 Vienna botanical congress rejected the name Cactus and instead declared Mammillaria was the type genus of the family Cactaceae. It did, however, conserve the name Cactaceae, leading to the unusual situation in which the family Cactaceae no longer contains the genus after which it was named. The difficulties continued, partly because giving plants scientific names relies on " type specimens ". Ultimately, if botanists want to know whether

9727-564: The ground or from branches very low down, such as in Stenocereus thurberi . Smaller cacti may be described as columnar. They consist of erect, cylinder-shaped stems, which may or may not branch, without a very clear division into trunk and branches. The boundary between columnar forms and tree-like or shrubby forms is difficult to define. Smaller and younger specimens of Cephalocereus senilis , for example, are columnar, whereas older and larger specimens may become tree-like. In some cases,

9864-507: The ground. The leafless, spiny stem is the characteristic feature of the majority of cacti (all belonging to the largest subfamily, the Cactoideae ). The stem is typically succulent, meaning it is adapted to store water. The surface of the stem may be smooth (as in some species of Opuntia ) or covered with protuberances of various kinds, which are usually called tubercles. These vary from small "bumps" to prominent, nipple-like shapes in

10001-441: The growing season and then lost (as in many species of Opuntia ). The small genus Maihuenia also relies on leaves for photosynthesis. The structure of the leaves varies somewhat between these groups. Opuntioids and Maihuenia have leaves that appear to consist only of a midrib. Even those cacti without visible photosynthetic leaves do usually have very small leaves, less than 0.5 mm (0.02 in) long in about half of

10138-511: The high accuracy of the Gee system was not needed, which greatly reduced the need to address the timing problems. This change in purpose also demanded the use of even lower frequencies, which could reflect off the ionosphere at night and thus provide over-the-horizon operation. Two frequency bands were initially selected, 1.85 and 1.95 MHz for nighttime use (160 meters), and 7.5 MHz (40 meters). The 7.5 MHz, labeled "HF" on early receivers,

10275-401: The highest possible volume for water storage with the lowest possible surface area for water loss from transpiration . The tallest free-standing cactus is Pachycereus pringlei , with a maximum recorded height of 19.2 m (63 ft), and the smallest is Blossfeldia liliputiana , only about 1 cm (0.4 in) in diameter at maturity. A fully grown saguaro ( Carnegiea gigantea )

10412-493: The indigenous people of the island, who called it Abawana, meaning "the First Small Land" . The Spanish later called it Amuana. Grand Turk was first colonised in 1681 by Bermudians, who set up the salt industry in the islands. In 1766 it became the capital of the country. For some time, at least until the early 19th century, Grand Turk was often referred to as Grand Cay, not to be confused with either Grand Cay in

10549-404: The intensity and focus controls to fine tune the signal and provide a sharp display. At the lowest sweep speed, the system also produced a local signal that was fed into the display and produced a sharply defined "pedestal", a rectangular shape displayed along the two traces. The amplified signal from the stations would also appear on the display, highly compressed in time so that it displayed as

10686-483: The level of genera. Their system has been used as the basis of subsequent classifications. Detailed treatments published in the 21st century have divided the family into around 125–130 genera and 1,400–1,500 species, which are then arranged into a number of tribes and subfamilies. The ICSG classification of the cactus family recognized four subfamilies, the largest of which was divided into nine tribes. The subfamilies were: Molecular phylogenetic studies have supported

10823-691: The matter with the husband, a third visitor arrived and he offered the men cigarettes. They refused, and the hostess then asked if they drank. When they said they did not, the land was quickly secured. LORAN was soon ready for deployment, and the first chain went live in June 1942 at Montauk and Fenwick. This was joined shortly thereafter by two stations in Newfoundland , at Bonavista and Battle Harbour , and then by two stations in Nova Scotia, at Baccaro and Deming Island. Additional stations all along

10960-455: The much smaller Maihuenia . These two groups are rather different from other cacti, which means any description of cacti as a whole must frequently make exceptions for them. Species of the first three genera superficially resemble other tropical forest trees. When mature, they have woody stems that may be covered with bark and long-lasting leaves that provide the main means of photosynthesis. Their flowers may have superior ovaries (i.e., above

11097-548: The north, with the exception of Rhipsalis baccifera , which is also found in Africa and Sri Lanka . Cacti are adapted to live in very dry environments, including the Atacama Desert , one of the driest places on Earth. Because of this, cacti show many adaptations to conserve water. For example, almost all cacti are succulents , meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents,

11234-511: The older receivers were made surplus. These older units were snapped up by commercial fishermen and other users, keeping it in widespread service. Loran-A continued to improve as the receivers were transistorized and then automated using microcontroller -based systems that decoded the location directly. By the early 1970s such units were relatively common, although they remained relatively expensive compared to devices like radio direction finders . The improvement of electronics through this period

11371-407: The operator would see a string of sharp "blips", first the primary, then one of the secondaries, the primary again, and then the other secondary. Gee CRTs were built to be able to display two traces, and by tuning several delay circuits, the operator could make the first primary-secondary signal appear on the upper display and the second on the lower. They could then take a measurement of both delays at

11508-541: The order of a few tens of feet, but ran into significant technical problems. The U.S. Air Force worked on a different concept, Cyclan, which the Navy took over as Loran-C , which offered longer range than LORAN and accuracy of hundreds of feet. The U.S. Coast Guard took over operations of both systems in 1958. In spite of the dramatically improved performance of Loran-C, LORAN, now known as Loran-A (or "Standard LORAN"), would become much more popular during this period. This

11645-403: The other two (primary and the third station) used repetition rate 1. The PRF could be adjusted from 25 to 25 and 7/16th for Low, and 33 1/3 to 34 1/9th for High. This system shared the middle tower, which broadcast on both frequencies. In the case of Gee, signals were direct from the transmitter to receiver, producing a clean signal that was easy to interpret. If displayed on a single CRT trace,

11782-486: The other, 150 km from one and 300 from the other, and so on. When plotted on a chart, the collection of possible locations for any given time difference forms a hyperbolic curve. The collection of curves for all possible measured delays forms a set of curved radiating lines, centered on the line between the two stations, known as the "baseline". In order to take a fix, the receiver takes two measurements based on two different primary/secondary pairs. The intersections of

11919-421: The outer epidermis, a hypodermal layer developed made up of cells with thickened walls, offering mechanical support. Air spaces were needed between the cells to allow carbon dioxide to diffuse inwards. The center of the stem, the cortex, developed " chlorenchyma " – a plant tissue made up of relatively unspecialized cells containing chloroplasts , arranged into a "spongy layer" and a " palisade layer " where most of

12056-449: The photosynthesis occurs. Naming and classifying cacti has been both difficult and controversial since the first cacti were discovered for science. The difficulties began with Carl Linnaeus . In 1737, he placed the cacti he knew into two genera, Cactus and Pereskia . However, when he published Species Plantarum in 1753—the starting point for modern botanical nomenclature—he relegated them all to one genus, Cactus . The word "cactus"

12193-442: The plant and water escapes, does not take place during the day at the same time as photosynthesis, but instead occurs at night. The plant stores the carbon dioxide it takes in as malic acid , retaining it until daylight returns, and only then using it in photosynthesis. Because transpiration takes place during the cooler, more humid night hours, water loss is significantly reduced. Many smaller cacti have globe-shaped stems, combining

12330-453: The points of attachment of the sepals and petals) and areoles that produce further leaves. The two species of Maihuenia have succulent but non-photosynthetic stems and prominent succulent leaves. Cacti show a wide variety of growth habits , which are difficult to divide into clear, simple categories. Cacti can be tree-like (arborescent), meaning they typically have a single more-or-less woody trunk topped by several to many branches . In

12467-468: The precise target array the facility was the terminus of one of the Broad Ocean Area (BOA) MILS that could give good location data over large ocean areas. From 1957 to 1959 USN Mobile Construction Battalion 7 constructed a LORAN Station on the island. In 1962, John Glenn 's Friendship 7 Mercury spacecraft landed in the vicinity of Grand Turk off the southeast shoreline. A replica of

12604-456: The price of limiting the amount of carbon fixed from the atmosphere and thus available for growth. CAM-cycling is a less water-efficient system whereby stomata open in the day, just as in plants using the C 3 mechanism. At night, or when the plant is short of water, the stomata close and the CAM mechanism is used to store CO 2 produced by respiration for use later in photosynthesis. CAM-cycling

12741-421: The primary arrive, it triggers its own transmitter. This ensures that the primary and secondary send out signals precisely 1 ms apart, without the secondary needing an accurate timer of its own or to synchronize its clock with the primary. In practice, a fixed time is added to account for delays in the receiver electronics. A receiver listening for these signals and displaying them on an oscilloscope will see

12878-523: The pulses as a whole, and the waves within them. These concepts led to experiments with Low Frequency LORAN in 1945, using a much lower frequency of 180 kHz. A system with three transmitters was set up on the US east coast using long antennas supported by balloons. The experiments demonstrated that the inaccuracy inherent to the design while working at such low frequencies was simply too great to be useful; operational factors introduced errors that overwhelmed

13015-414: The radio signal from one will take 1  millisecond to reach the other. One of these stations is equipped with an electronic clock that periodically sends out a trigger signal. When the signal is sent, this station, the "primary", sends out its transmission. 1 ms later that signal arrives at the second station, the "secondary". This station is equipped with a receiver, and when it sees the signal from

13152-426: The range. Thus at short distances the lines cross at angles close to 90 degrees, and this angle steadily reduces with range. Because the accuracy of the fix depends on the crossing angle, all hyperbolic navigation systems grow increasingly inaccurate with increasing range. Moreover, the complex series of received signals considerably confused the reading of the LORAN signal, requiring some interpretation. Accuracy

13289-539: The receiver unit. This would prove extremely useful; RAF Transport Command aircraft could swap their receivers when moving to or from the Australian theatre. Dippy also designed the ground station timing equipment. It was around this time that the project was joined by both the U.S. Coast Guard and the Royal Canadian Navy . The project was still top secret at this time, and little actual information

13426-457: The rest of the world until 1985. A Japanese chain remained on the air until 9 May 1997, and a Chinese chain was still listed as active as of 2000 . Loran-A used two frequency bands, at 1.85 and 1.95 MHz. These same frequencies were used by radio amateurs , in the amateur radio 160-meter band , and amateur operators were under strict rules to operate at reduced power levels to avoid interference; depending on their location and distance to

13563-402: The same time. In comparison, LORAN was deliberately designed to allow skywaves to be used, and the resulting received signal was far more complex. The groundwave remained fairly sharp, but could be received only at shorter distances and was primarily used during the day. At night, as many as thirty different skywaves might be received from a single transmitter, often overlapped in time, creating

13700-415: The sea. Using cycle matching, the system demonstrated an accuracy of 160 feet (49 m) at 750 miles (1,210 km). But it was also discovered that the system was very difficult to use and the measurements remained subject to confusion over which cycles to match. During this same period, the U.S. Army Air Force became interested in a very-high accuracy system for bombing pinpoint targets. Raytheon won

13837-402: The secondary on the second, allowing the complex patterns to be compared. This meant that only one primary/secondary measurement could be made at once; to produce a "fix", the entire measurement procedure had to be repeated a second time using a different set of stations. Measurement times on the order of three to five minutes were typical, requiring the navigator to take into account the motion of

13974-431: The sepals and petals cannot be clearly differentiated (and hence are often called " tepals "). Some cacti produce floral tubes without wool or spines (e.g. Gymnocalycium ) or completely devoid of any external structures (e.g. Mammillaria ). Unlike the flowers of most other cacti, Pereskia flowers may be borne in clusters. Cactus flowers usually have many stamens , but only a single style , which may branch at

14111-476: The ships and aircraft operating in the Pacific theater during World War II. LORAN, in its original form, was an expensive system to implement, requiring a cathode ray tube (CRT) display. This limited use to the military and large commercial users. Automated receivers became available in the 1950s, but the same improved electronics also opened the possibility of new systems with higher accuracy. The U.S. Navy began development of Loran-B , which offered accuracy on

14248-477: The shore, U.S. operators were limited to maximums of 200 to 500 watts during the day and 50 to 200 watts at night. The "National Timing Resilience and Security Act" of 2017, proposed repurposing LORAN real estate and radio spectrum for a new terrestrial navigation system as a backup for the United States in case of a GPS outage caused by space weather or attack. eLoran has been proposed as

14385-424: The signals inverted and running at a lower sweep speed so that multiple repetitions of the signal appear on the traces. Mixed into the signal is an electronic scale produced in a time base generator , causing a series of small pips to appear over the now-inverted original signals. At setting 5, the pips on the scale represent differences of 10 microseconds, and the operator measures the distance between positions. This

14522-421: The signals were so much longer and more complex than Gee that direct measurement of the two signals was simply not possible. Even the initial signal from the primary station was spread out in time with the initial groundwave signal being sharp (if received), while the skywave receptions could appear anywhere on the display. Accordingly, the LORAN operator set the delays so the primary signal appeared on one trace and

14659-418: The skywaves became useful for measurements, which extended the effective range to 1,200–1,400 nautical miles (2,200–2,600 km). At long ranges the hyperbolic lines approximate straight lines radiating from the center of the baseline. When two such signals from a single chain are considered, the resulting pattern of lines becomes increasingly parallel as the baseline distance becomes smaller in comparison to

14796-487: The species of Leuenbergeria , Pereskia and Rhodocactus are superficially like normal trees or shrubs and have numerous leaves with a midrib and a flattened blade (lamina) on either side. This group is paraphyletic , forming two taxonomic clades . Many cacti in the opuntia group (subfamily Opuntioideae ) also have visible leaves, which may be long-lasting (as in Pereskiopsis species) or produced only during

14933-666: The species studied and almost always less than 1.5 mm (0.06 in) long. The function of such leaves cannot be photosynthesis; a role in the production of plant hormones, such as auxin , and in defining axillary buds has been suggested. Botanically, " spines " are distinguished from "thorns": spines are modified leaves, and thorns are modified branches. Cacti produce spines, always from areoles as noted above. Spines are present even in those cacti with leaves, such as Pereskia , Pereskiopsis and Maihuenia , so they clearly evolved before complete leaflessness. Some cacti only have spines when young, possibly only when seedlings. This

15070-513: The stem acts as the main organ for storing water, some cacti have in addition large taproots . These may be several times the length of the above-ground body in the case of species such as Copiapoa atacamensis , which grows in one of the driest places in the world, the Atacama Desert in northern Chile. Photosynthesis requires plants to take in carbon dioxide gas (CO 2 ). As they do so, they lose water through transpiration . Like other types of succulents , cacti reduce this water loss by

15207-481: The stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines , which are highly modified leaves. As well as defending against herbivores , spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of true leaves, cacti's enlarged stems carry out photosynthesis . Cactus spines are produced from specialized structures called areoles ,

15344-433: The stems from which spines emerge. Flowers are also produced from areoles. In the genus Leuenbergeria , believed similar to the ancestor of all cacti, the areoles occur in the axils of leaves (i.e. in the angle between the leaf stalk and the stem). In leafless cacti, areoles are often borne on raised areas on the stem where leaf bases would have been. Areoles are highly specialized and very condensed shoots or branches. In

15481-493: The subfamily Opuntioideae have relatively short spines, called glochids , that are barbed along their length and easily shed. These enter the skin and are difficult to remove due to being very fine and easily broken, causing long-lasting irritation. Most ground-living cacti have only fine roots , which spread out around the base of the plant for varying distances, close to the surface. Some cacti have taproots ; in genera such as Ariocarpus , these are considerably larger and of

15618-600: The system provided coverage anywhere south of Scotland and as far east as Poland with an average accuracy of one mile. The system was used operationally in October 1944, and by 1945 it was universally installed in No. 5 Group RAF . The same basic concept was also tested post-war by the Coast Guard in a system known as "Skywave Long Baseline LORAN". The only difference was the selection of different frequencies, 10.585 MHz in

15755-486: The team instead settled on two abandoned Coast Guard stations at Montauk Point , New York, and Fenwick Island, Delaware . On the receiving end, a station wagon was fitted with a simple receiver and sent around the country looking for solid signals, which were found as far away as Springfield, Missouri . For a production system, the team began working with a system using a circular J-scope display for improved accuracy. The more common A-scope represents distances across

15892-410: The temperature of the surface of the cactus, also reducing water loss. When sufficiently moist air is present, such as during fog or early morning mist, spines can condense moisture, which then drips onto the ground and is absorbed by the roots. The majority of cacti are stem succulents , i.e., plants in which the stem is the main organ used to store water. Water may form up to 90% of the total mass of

16029-529: The timing. This system, later known as Loran-B , ran into significant problems (as did another Air Force system, Whyn and a similar British system, POPI ). In 1953 the Navy took over the Cyclan system and began a wide series of studies ranging as far away as Brazil, demonstrating accuracy to about 100 meters (330 ft). The system was declared operational in 1957, and operations of LORAN and Cyclan were handed to

16166-422: The top of the stem then produces flowers, the other part spines. Areoles often have multicellular hairs ( trichomes ) that give the areole a hairy or woolly appearance, sometimes of a distinct color such as yellow or brown. In most cacti, the areoles produce new spines or flowers only for a few years and then become inactive. This results in a relatively fixed number of spines, with flowers being produced only from

16303-504: The two sets of curves normally result in two possible locations. Using some other form of navigation, dead reckoning for instance, one of these possible positions can be eliminated, thus providing an exact fix. LORAN stations were built in chains, one primary and two secondaries (minimally, some chains were constituted of as many as five stations) typically separated by about 600 miles (970 km). Each pair broadcast on one of four frequencies, 1.75, 1.85, 1.9 or 1.95  MHz (as well as

16440-760: The ultimate end of the Chinese Communist Revolution , and these stations remained on the air at least into the 1990s. A final major expansion took place in Portugal and the Azores in 1965, offering additional coverage to the mid-Atlantic. During early experiments with LORAN's skywaves, Jack Pierce noticed that at night the reflective layer in the ionosphere was quite stable. This led to the possibility that two LORAN stations could be synchronized using skywave signals, at least at night, allowing them to be separated over much greater distances. Accuracy of

16577-409: The unused 7.5 MHz). In any given location it was common to be able to receive more than three stations at a time, so some other means of identifying the pairs was needed. LORAN adopted the use of varying the pulse repetition frequency (PRF) for this task, with each station sending out a string of 40 pulses at either 33.3 or 25 pulses per second. Stations were identified with a simple code, with

16714-400: The upper pedestal until one of the signal spikes was centred within it, and then moved the pedestal on the lower trace to center a second signal using coarse and fine delay controls. Once this was done, the system was set to sweep speed 2, which sped up the traces so that the section outlined by the pedestals filled the entire trace. This process was repeated at sweep speed 3, at which point only

16851-478: The vehicle during this time. The original airborne receiver unit was AN/APN-4 unit of 1943. It was physically identical to the UK's two-piece Gee set, and could be easily interchanged with these units. The main unit with the display also housed most of the controls. General operation started by selecting one of nine stations, labeled 0 to 8, and setting the sweep speed to 1, the lowest setting. The operator would then use

16988-460: The way in which they carry out photosynthesis. "Normal" leafy plants use the C 3 mechanism : during daylight hours, CO 2 is continually drawn out of the air present in spaces inside leaves and converted first into a compound containing three carbon atoms ( 3-phosphoglycerate ) and then into products such as carbohydrates . The access of air to internal spaces within a plant is controlled by stomata , which are able to open and close. The need for

17125-459: Was basal within the Cactaceae, but confirmed earlier suggestions it was not monophyletic , i.e., did not include all the descendants of a common ancestor. The Bayesian consensus cladogram from this study is shown below with subsequent generic changes added. Pereskia s.l. Clade A → Leuenbergeria Pereskia s.l. Clade B → Rhodocactus + Pereskia s.s. Opuntioideae Maihuenia LORAN LORAN ( Long Range Navigation )

17262-537: Was a hyperbolic radio navigation system developed in the United States during World War II . It was similar to the UK's Gee system but operated at lower frequencies in order to provide an improved range up to 1,500 miles (2,400 km) with an accuracy of tens of miles. It was first used for ship convoys crossing the Atlantic Ocean, and then by long-range patrol aircraft, but found its main use on

17399-542: Was also at the 20 December meeting. He stated that he was aware of similar work in the UK, but didn't know enough about it to offer any suggestions. Project 3 moved to the newly formed Radiation Laboratory 's Navigation Group in 1941. Early systems operated around 30 MHz, but it was later decided to try experiments with different equipment that could be tuned from 3 to 8 MHz. These lower frequency systems were found to be much more stable electronically. After first considering setting up transmitters on mountain peaks,

17536-554: Was commissioned 23 October 1954 and was active until decommissioned 31 March 1980. The actual undersea surveillance mission of the system and shore facility remained classified through decommissioning. The NAVFAC was located ( 21°30′43.6″N 71°07′57.7″W  /  21.512111°N 71.132694°W  / 21.512111; -71.132694 ) near the Grand Turk Lighthouse. Grand Turk, located about 700 nmi (810 mi; 1,300 km) from Cape Canaveral , became

17673-406: Was definitely possible, leading to some interest by the U.S. Army Air Force . The Navy was unhappy about this turn of events. Dippy also instituted a number of simple changes that would prove extremely useful in practice. Among these, he outright demanded that the airborne LORAN receivers be built physically similar to the Gee receivers, so that they could be swapped out in service simply by replacing

17810-477: Was due largely to the large numbers of surplus Loran-A units released from the Navy as ships and aircraft replaced their sets with Loran-C. The widespread introduction of inexpensive microelectronics during the 1960s caused Loran-C receivers to drop in price dramatically, and Loran-A use began to rapidly decline. Loran-A was dismantled starting in the 1970s; it remained active in North America until 1980 and

17947-465: Was in its infancy, and their signals were considerably spread out in time, making measurements difficult. By this time the team had become aware of the UK's Gee efforts, and were aware that Gee used a system of electronically generated strobes that produced pips on the display that were accurately aligned with system timing. They sent a team to the UK to learn about the strobe concept, and immediately adopted it for their work. As part of this exchange,

18084-428: Was more a matter of signal quality and operator experience than any fundamental limit of the equipment or signals. The only way to express the accuracy was to measure it in practice; average accuracy on the route from Japan to Tinian, a distance of 1,400 miles (2,300 km), was 28 miles (45 km), 2% of range. AT LORAN, for "Air Transportable", was a lightweight LORAN transmitter set that could be rapidly set up as

18221-582: Was never used operationally. In mid-1942, Robert Dippy , the lead developer of the Gee system at the Telecommunications Research Establishment (TRE) in the UK, was sent to the US for eight months to help with LORAN development. At the time the project was being driven primarily by Captain Harding of the U.S. Navy, and they were concentrating entirely on a shipboard system. Dippy convinced them that an airborne version

18358-562: Was not Guanahani but Babueca , an island separately discovered by Martín Alonso Pinzón in November - December 1492. A U.S. Naval Facility (NAVFAC), the name given for a shore terminus of an offshore surveillance array of the Sound Surveillance System (SOSUS), was established on Grand Turk in 1954 as one of three additional Atlantic systems installed that year during the first phase of SOSUS installation. The facility

18495-462: Was quickly supplanted by the AN/APN-9 of 1945, an all-in-one unit combining the receiver and display of greatly reduced weight. During the day the ionosphere only weakly reflects shortwave signals, and LORAN was usable at 500–700 nautical miles (930–1,300 km) using the groundwaves. At night these signals were suppressed and the range dropped to 350–500 nautical miles (650–930 km). At night

18632-622: Was shared, especially with the Coast Guard. The Canadian liaison was required, as ideal siting for the stations would require several stations in various locations in the Canadian Maritime Provinces . One site in Nova Scotia proved to be a battle; the site was owned by a fisherman whose domineering teetotaler wife was dead set against having anything to do with the sinful Navy men. When the site selection committee of J.A. Waldschmitt and Lt. Cdmr. Argyle were discussing

18769-419: Was so rapid that it was only a few years before Loran-C units of similar size and cost were available. This led to the decision to open Loran-C to civilian use in 1974. By the late 1970s, the Coast Guard was in the midst of phasing out Loran-A in favor of additional Loran-C chains. The Aleutian and Hawaii chains shut down on 1 July 1979, the remaining Alaska and West Coast chains on 31 December 1979, followed by

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