Urban civilizations, from Egyptian and Mesopotamian medicine systems developed, including a conceptual or theoretical body, a more or less standard practice, the regulation of medical education, belonging to the profession and the responsibilities of the physician.

Other systems have survived until today, and the health systems of the countries concerned have integrated them in varying degrees. They are:

Ayurveda or Ayurvedic medicine. Originating in India at an indeterminate time, but already in Vedic times, the fourth of the Vedas, the Atharvaveda contains some elements. He has penetrated some Western environments, which represents a form of alternative medicine.

Traditional Chinese medicine. Arisen medicine in China to the fourteenth or thirteenth century BC, was an essentially practical magic influence of Taoism and Confucianism made it evolve, adopting a pharmacopoeia

Grecoárabe or unani medicine (which in Arabic means “Greek”). Hospitals that came under his influence tended the sick regardless of their social status or religion. They were secular institutions, but in any case approved and valued by Islam.

Traditional Medicine Andean emerged mainly in the Peruvian Andes and Ecuadorian health based on the balance warm / cold and the world’s animistic thought, methodology of explaining the holistic sense of life, traditional health agents assume their role as a divine gift and based his speech on the restitution of the balance with rituals and plants medicinales3
Mesoamerica For the best example is Don Juan Badiano and Don Martin de la Cruz.

bird

There are several traditional remedies, some examples include:
Aceitilla (acahual, white acahual, rosilla, arrowhead)
Botanical name: Bidens pilosa L. family Compositae.
Places where vegetation: A weed of the valley of Mexico, Veracruz, Jalisco, Oaxaca, etc..
Characters: Measures from 50 to 150 cm in height, its stem tetragon from the base, pubescent on the upper, petiolate leaves and white flowers in heads. Flowers from August to October.
Parts used: The whole plant.
Common Uses: Often used as tea.

Acocote (cumin, cumin rustic, bear grass)
Botanical Name: Arracacia atropurpurea. Benth the hook. Umbelliferae family.
Places of vegetation: Valley of Mexico, State of Mexico, Veracruz, San Luis Potosi, Michoacan, Morelos, etc.. Usually at elevations between 2,200 and 2,800 m. above the sea.
Characters: Herbaceous large divided leaves and flowers in umbels, fruits oblong-elliptical, compressed, with 5 ribs, three dorsal and two marginal. They are pungent and aromatic.
Parts used: Fruits, contains essential oil.
Common Uses: Used for gonorrhea, as a carminative and stimulant, used elsewhere for fever

Achiote (achiotillo, achiotl, changuarica, pumacua)
Botanical name: Bixa orellana L. Family of bixáceas.
Places where vegetation: Yucatán, Campeche, Quintana Roo, Chiapas, Tabasco, Veracruz, Oaxaca, Sinaloa, Morelos, etc..
Characters: bush about three to four meters, with leaves alternate, pecionaladas, cordate, entire, watery and smooth, up to 20 cm long hermaphrodite flowers, pink, arranged in corymbs, the heart-shaped fruit is a capsule about 5cm long red and dark red first then bristling with stiff hairs, dehiscent by two valves. Seeds almost triangular, somewhat compressed and fleshy seed coat, red. Flowers in November and harvested in March and April
Parts used: grains, oil them and leaves.
Common Uses: This macerated in oil and applied to burns, is credited with stomachic properties, dysentery and refreshing. The leaves chopped and macerated in small quantity of water, produce a gummy substance that is said to have diuretic properties and antigonorreicas, the same substance is purgative and desinflamatoria.

Balm
Botanical Name: myroxylon balsamum var. Pereirae (royle) harms. Family Leguminosae.
Places where vegetation: Veracruz, Michoacan, Oaxaca, Chiapas, Yucatan among other warm places.
Characters: Tree 15-20 meters compound leaves odd-pinnate, consisting of 7-17 leaflets alternate, ovate-acuminate, thin, bright, full-dot cross. White flowers, small and arranged in clusters.
Parts used: Fruits and trunk (black salve)
Common Uses: Used for asthma, colds, rheumatism etc. Also used against gonorrhea.

Source: http://herbalteasource.com
Source: Medicina tradicional

Part of survivalism is figuring out how to survive off the land. I will be featuring some great herbs here. First up, Dandelion

This annual and perennial plant has a long taproot and basal rosette, rarely reaches more than 40-50 cm. 4 have alternate lanceolate leaves with a midrib, without distinct petiole, pinnatipartidas with triangular shaped lobes toothed margins and treble sometimes presents microvilli. The stem is always extremely shortened, which is why plants are called stemless. They are also capable of producing an inflorescence elongated internode, denominating escape. Peduncle of inflorescence hollow breaking that exudes a bitter milky juice. Hermaphrodite flowers of golden yellow make them easily identifiable, completed in five small teeth. Dandelions bloom in spring to late summer. The fruit is an achene with pappus cipsela or known as “bakers” (in Spain as dandelion).

It also makes for great dandelion root tea!

Some of this article was sourced from http://herbalteasource.com, click here to learn more.

Commonly found on the roads, pastures, meadows, direct seeding, and especially in gardens, so it is considered a weed or “weeds”, by gardeners.

It is a purifying plant, indicated to purify the body of toxic elements. May act on the liver, kidney and gall bladder, and its diuretic effect prevents the onset of kidney stones. It is also a digestive tonic for constipation and alcohol hangover. For topical use is effective to clean impurities from the skin, acne, urticaria. These properties are for their content of inulin, phenolic acids, minerals, and other substances which provide benefits in piel. At certain times of scarcity, the dried root was used as a substitute for the chicory, which in turn was a substitute coffee. Leaf vegetables were used for salads although unconfirmed crop existence for this purpose.

However, Font Quer Dioscórides renewed in the presence of said crops by Leon root latex rich rubber (unspecified Taraxacum species in question).

It is one of the main species of flora of the prairies beekeeping, bees visit the flowers unfailingly, delivering a very good amount of nectar and pollen. By their almost ubiquitous distributio, dandelions are known known worldwide by beekeepers.

This plant is commonly used in folk medicine for various recipes and remedies, primarily to treat symptoms of problems with the liver, digestive system, and breast.

In herbal medicine it is also used for the active ingredients in infusions, mainly for lack of appetite, indigestion and liver disturbances.

Its leaves contain lots of vitamin A, C, iron, carrying more iron and calcium than spinach or other hortalizas.

In the culinary arts Mediterranean salad is often made for spring cleansing with only dandelion leaves or mixed with other vegetables.
Also the flower petals can contribute to flavor and color to mixed salads. The flower buds are appreciated if prepared with olive oil. The flowers can also be prepared in pastel and even fried (sautéed). The young shoots can be eaten plain or with extra virgin olive oil or sauteed in a pan with garlic (or even better with garlic ursine).

In many regions of Europe is preparing a Taraxacum flower jam.

Boil in open pan for about 20 minutes, filter and keep the liquid, add 1 kg of sugar, boil in open pan until the desired density, pour (boiling) fluid obtained, thick, in good clean glasses (sterilized) and close tightly.

The leaves of this plant are one of the ingredients of preboggion, mixed herbs typical of Ligurian cuisine.

Survivalism (survivalism) is the movement of individuals or groups (called “survivalists”) who are actively preparing for future possible disorderly political or social, whether local, regional, national or International. The survivalists frequently prepared in advance for these events by either receiving medical training, stockpiling food and water, preparing for self-defense or self-sufficiency, and / or constructing buildings that will help them survive and shelter.
Index

The survivalism, also called survivalism, is approached by his adherents in different ways, depending on the circumstances and their particular concerns and also the risks that can happen in the future. The following are just some examples, although many survivalists fit into more than one of these categories:
Possible Scenarios

Among scenarios or potential threats can be distinguished as the predominant cause among those that have their origin in human activity and among those that have natural causes.

natural disaster forms of apocalyptic planetary crises or Earth changes such as earthquakes, tsunamis, floods, tornadoes, hurricanes, snow, and severe thunderstorms.
Threats of extra-terrestrial origin, such as the possible impact of a meteorite, a possible alien invasion and / or any other form of threat of space origin.
A disaster caused by human activity: conventional warfare, chemical warfare, biological warfare, nuclear war, radioactive contamination, and other disasters caused by an enemy government.
General collapse of society, resulting from the unavailability of food, water, electricity and fuel.
Bankruptcy monetary or economic crisis, caused by monetary manipulation, hyperinflation, deflation, and / or global economic depression.
A sudden pandemic spreading through the population.
Widespread famine and rising food prices.
Generalized chaos, and any other unexplained apocalyptic event.
Other potential threats include: information warfare, terrorism, and weapons of mass destruction.

The most common preparations include preparing a shelter, in a safe place, and the storage of water and nonperishable food, canned food, supplies, water purification equipment, warm clothing, seeds, wood, fuel, firearms, ammunition , hunting weapons and self-defense, first aid medical equipment and agricultural tools. Many people do not make all these preparations, the survivalists if they do, because their way of life is to be prepared.
State Preparations

Several countries have government agencies or specifically intended to plan, promote, manage and implement actions for prevention, response and rehabilitation versus collective risk situations such as emergencies, disasters and catastrophes of natural or caused by human activity, through coordination of response system networks in order to provide protection for people, property and the environment.

The oldest known map is controversial, because the definition of map is not unambiguous and because for mapping different materials were used. There is a mural, which may represent the ancient city of Çatalhöyük in Anatolia (previously known as Catal Huyuk or Hüyük), dating from the seventh millennium BC. C.1 2 Other known maps of the ancient world include the Minoan civilization: the “House of the Admiral” is a wall painting dating from 1600 to. C., in which there is a seaside community in an oblique perspective. There is also an engraved map of the Holy City of Nippur Babylonian, Kassite period (fourteenth century. C. – Century XII a.) 3

In ancient Greece and the Roman Empire maps were created, such as Anaximander in the sixth century. C.4 or Ptolemy world map, a map of the known world (Ecúmene) by Western society in the Century II d. C. In the eighth century, Arab scholars translated the works of the Greek geographers to árabe.5

In ancient China, geographical codes dating from the fifth century The maps are older Chinese State of Qin and are dated in the fourth century, during the Warring. In the book of the Xin Yi Xiang Fa Yao, published in 1092 by the Chinese scientist Su Song, there is an astronomical chart with a cylindrical projection similar to the current and apparently invented separately to 7 Though Mercator.6 Projection this method of calculation seems to have existed in China even before this publication, and scientifically, the meaning of the Letters largest astronomical Your Song, is representing the oldest existing printed maps known.

The first signs of Indian cartography included legendary paintings, maps of locations described in Hindu epics such as the Hindu Rāmāyana.8 cartographic traditions also placed the location of the North Star and other constelaciones.9

World Map is the general term used to describe Medieval European maps of the world. Approximately 1,100 globes survived the Middle Ages. Of these, 900 are illustrations handwritten and the rest exists as separate documents (Woodward, P. 286).
Tabula Rogeriana, map drawn by Muhammad al-Idrisi for Roger II of Sicily in 1154.

The Arab geographer, Muhammad al-Idrisi, produced his map, the Tabula Rogeriana, in 1154, incorporating known Africa, the Indian Ocean and the Far East known, compiling information from the Arab traders and explorers and inherited from the classical geographers to create the most accurate map of the world in his time and for the next three siglos.10

In the Age of Discovery, from the fifteenth to the seventeenth century, European cartographers copied old maps (some dating back centuries) and drew their own maps based on observations of the explorers but with new techniques. The invention of the compass, telescope and the development of surveying gave them greater accuracy. In 1492, Martin Behaim, German cartographer, made the first globe, the Erdapfel.11

Johannes Werner studied and perfected projection systems maps, heart-shaped projection developed. In 1507, Martin Waldseemüller produced a world globe and a large world map mural distributed in 12 sheets (Universalis Cosmographia), the first map to apply the name “America” ​​to the lands newly discovered by Europeans and the first to introduce this separated from the Asian continent. The Portuguese cartographer Diego Ribero, was the author of the first known planisphere with terrestrial Ecuador Graduate (1527). The Italian cartographer Baptist Agnese produced at least 71 manuscript atlases of sea charts.

Because of the difficulties inherent in cartography, map-makers frequently copied material from earlier works without mentioning the original cartographer. For example, one of the most famous early maps of America, commonly known as the “Beaver Map”, published in 1715 about Herman Moll, is an exact reproduction of a 1698 work by Nicolas de Fer. De Fer in turn had copied images printed in books by Louis Hennepin, published in 1697, and François Du Creux, in 1664. By the 1700s, manufacturers began mapping to credit the original author by printing the phrase “According to [the original cartographer]” .12

With the addition of some basic tools to aid navigation, along with a clock, it adopted a more elaborate navigation technique: reckoning. Firstly joined compass, used to obtain the magnetic heading (angle between the aircraft longitudinal axis from bow to stern with respect to magnetic north).

Moreover, considering the importance of knowing the flight altitude and speed of the aircraft, joined the so-called Pitot tube, giving through measures air pressure (static and dynamic), the following information:

Altitude (vertical distance of the plane relative to mean sea level), which is measured by the altimeter.
Indicated speed (speed of the aircraft with respect to air), which is determined with anemometer.
Degree of climb or descent (vertical speed of the aircraft), calculated with the variometer.

When an aircraft has to perform a flight with a purpose, it must be planned building on the maps of the terrain, the route that is to follow. As you know the unit rate by the anemometer, you could estimate the time you reach the next point on the route, using the equation of uniform motion:

distance = rate x time

The industrial revolution of the early twentieth century had many factories flourish of towering chimneys were helpful initially to appreciate inaccurately wind speed over the ground. This form of wind followed by different estimation techniques based on the measurement of round-trip times of aircraft, covering a certain circle next to the airfield. Gradually methods were improved and built various wind speed calculators that have helped the crew to determine the speed of the aircraft from the ground.
Problems

However, the end station could be different from the planned, due to three causes:

Instrument errors.
Driving errors.
Windage.

Both errors due to the instruments used (compass, anemometer and clock), and human errors are inherent in any type of sailing, although they have fallen substantially over time.

The wind effect results in the re-routing if the wind blows in a different direction to the direction of the aircraft. If the wind has the same direction as the direction, not deviate from the path, but it will reach the destination earlier than expected if the tail wind is (for the plane), or later than planned if nose blowing (in against the plane). When the wind blows the plane consisted deviate laterally.

In reckoning, the problem is to determine the intensity and direction of the wind to correct the measured speed of the anemometer and get the actual path. This situation is known as the velocity triangle.

When there is wind, the actual path of the aircraft with respect to the planned changes, so what follows is really a direction determined by a known angle of defeat instead of course. This track is calculated from the course and speed of the aircraft indicated, together with the wind direction and intensity.

An early precursor of satellite navigation systems were terrestrial systems LORAN and Omega, who used low frequency radio transmitters (100 kHz) land instead of satellites. These systems disseminated a radio pulse from a location “master” known, followed by repeated pulses from a number of stations “slaves”. The delay between receiving and sending the signal was controlled auxiliary stations, allowing recipients to compare the delay between the reception and the delay between sent. Through this method can determine the distance to each of the auxiliary stations.

The first satellite navigation system was Transit, a system deployed by the U.S. military in the 1960s. Transit was based on the Doppler effect. The satellites travel in known paths and broadcast their signals at a known frequency. The received frequency differs slightly from the frequency spread due to satellite movement relative to the receiver. By monitoring this frequency shift at short intervals, the receiver can determine its location to one side or the other of the satellite, the combination of several of these measures, together with an accurate knowledge of the satellite’s orbit can set a specific position.
Theory and fundamental characteristics

Satellite navigation is based on calculating a position on the Earth’s surface by measuring the distances from at least three satellites of known position. A fourth satellite will provide further altitude. The accuracy of the distance measurements determines the ultimate location accuracy. In practice, a receiver receives the synchronization signals emitted by the satellites containing the satellite position and the exact time at which it was transmitted. Satellite position is transmitted in a data message that is superimposed on a code that serves as a timing reference.

The position accuracy depends on the accuracy of the time information. Atomic chronometers only provide the required accuracy, the order of nanoseconds (10 -9} ^ {s). For this, the satellite uses an atomic clock to be synchronized with all satellites in the constellation. The receiver compares the time of diffusion, which is encoded in the transmission, the reception time measured by an internal clock, so as to measure the “time of flight” of the signal from the satellite.
These timers are an essential technology aboard satellites that make up the GNSS constellations and can help define international weather patterns. Synchronization is improved by the inclusion of the signal emitted by a fourth satellite. In the design of the satellite constellation Special attention is paid to the selection of the number of these and their orbits, so they are always visible in sufficient quantity from anywhere in the world and thus ensure signal availability and accuracy.

Each measurement of distance to the receiver placed on a spherical shell within the measured distance. Taking several steps and then finding the point where they are cut, you get the position. However, in the case of a mobile receiver which moves quickly, the position of the signal moves while the signals from several satellites are received. Furthermore, the radio signals are delayed slightly as they pass through the ionosphere. The basic calculation attempts to find the shortest line tangent to four spherical shells centered on four satellites. The satellite navigation receivers reduce errors by using combinations of signals from multiple satellites and multiple correlations, then using techniques such as Kalman filters for combining partial data affected by noise and constantly changing, into a single estimate of position, time, and speed.
Applications
The precision-guided missile to target and smart bombs is one of military uses of GNSS.
Military use

The origin of satellite navigation was military. Satellite navigation sufficient for accuracy that had not been achieved until now, the objectives of weapons, increasing its effectiveness and reducing unwanted damage by weapons that uses GNSS signal yes produced conventional weapons . Satellite navigation also allows forces to be directed and easily locate.

In short, it can be considered a force multiplier. In particular, the ability to reduce unintentional deaths has particular advantages in the wars waged by democracies, where public opinion has a great influence on the war. For this reason, a satellite navigation system is essential for any military power.
Air navigation

The navigation uses, within the concept of Global Navigation Satellite System (GNSS) implemented by the International Civil Aviation Organization (ICAO), positioning systems, recognized as a key element in the Communications, Navigation and Surveillance to support the control of air traffic management (CNS / ATM) as well as a foundation upon which states can provide improved aeronautical navigation services. The states that allow GNSS operations are responsible for determining if it meets the performance requirements required for this activity (according to what specified by ICAO) in the airspace under their jurisdiction and to notify users when such performance is not meets these.

By concept, GNSS is a worldwide system for determining the position and time, which includes core satellite constellations, aircraft receivers, system integrity monitoring, and augmentation systems that improve the performance of the core constellations.

In short, the GNSS is a general term that includes all satellite navigation systems, which have already been implemented (GPS, GLONASS) and those in development (Galileo), proposing the use of satellites to support the navigation, offering precise location of aircraft and coverage across the globe. GNSS is being introduced in an evolutionary manner as to be prepared to accommodate the large volume of civil air traffic available today, and can respond to the security needs required in the sector, one of the most demanding in the world.

GNSS When fully developed, is expected to be used without requiring assistance of any other conventional navigation system, from takeoff to landing accurately complete a Category I, II or III, ie in all phases of flight .
Other civil uses
A car navigator

Some of civilian applications where GNSS signals are used are as follows:

Aids to navigation and guidance for hiking handhelds, embedded devices in cars, trucks, boats, etc..
Synchronization.
Emergency location systems.
Geomatics.
Tracking devices used in wildlife.
Etc.

Coastal navigation was practiced, no doubt, from the remotest antiquity. The Phoenicians were the first who sailed the high seas to the oar and sail, guided by the sun during the day, and the North Star at night. Ground that came to the South West coast of Africa and to England, but it is doubtful they crossed the Atlantic Ocean and addressed Brazil or Gulf of Mexico coasts as some claim. The Phoenicians taught navigation to the Greeks, who were quick to match them.

Knowledge of the compass transmitted to Europeans by Arabs (who had obtained from the Chinese) allowed long trips since the fourteenth century. In 1492, Columbus made contact with America, in 1498, Vasco de Gama doubled the Cape of Good Hope to go to India, from 1519-1521 the Portuguese expedition led by Ferdinand Magellan and then by the Spanish Juan Sebastian Elcano (both the service of Spain) turned around the world.1 Where was checking the length determination by the method of Rui Faleiro, scientific organizer of the trip.

As Felipe Picatoste recounts in “Notes for a Spanish scientific library of the sixteenth century biographical and bibliographical studies of natural and physical sciences and its immediate applications in this century” (1891), awarded by the National Library of Madrid, which collects data Spanish scientists biobibliográficos that during the sixteenth century, these blunted in their fields, remembering that until the sixteenth century Spanish hegemony was apparent in fields like geography, cosmography and navigation (both the British and the French pilots learned to navigate in the texts of Pedro de Medina, Martín Fernández de Enciso and Cortes, among others).
Maritime Navigation Techniques

Are the methods used in shipping, to solve the four problems the navigator:

Determine the course.
Determine the time, speed and distance, the duration of the trip.
Knowing the “depth” in which you are browsing for is not aground.

Coastal navigation

Navigation and ship’s position by positioning techniques based on the observation of delays and distances to significant points of the coast (Lighthouses, Cabos, buoys, etc..) By visual means (Taximeters), observing horizontal angles (Sextant) or electronic methods (Radar delays to racons, 2 transponders, etc..).
Reckoning
Main article: Navigating estimated (nautical).

Navigation and ship’s position by analytical means, after taking into account the following elements: baseline (So), Heading (s) taken, whether Bearings True (Rv), Directions of Surface (Rs) or Effective Bearings (Re) , speed (s) and external factors that have influenced the whole or part of the loss, such as wind (Gloom) and / or the Current (Rumbo current time and current intensity). The resulting point of the calculations is called Estima situation with its latitude and longitude of Esteem (you and I). At this point it is also known as a fantasy.
Plane sailing
Main article: Sailing rhumb.
Loxodrome.

Plane sailing is what is done following the same direction, ie, all meridians are cut at the same angle. In Chart R. In a rhumb line Mercator projection is represented by a straight line. This type of navigation is not very useful for large distances, as it offers the convenience of maintaining a steady course, but not the one that offers the shortest distance, so it is usually not suitable for long distances.
Great Circle Navigation
Main article: Sailing orthodromic.

Following is the shortest distance between two points, that is, is the one that follows a great circle. The calculations of bearing and distance between two points is necessary to solve a spherical triangle whose vertices are the origin, destination and polo.3
Celestial navigation

It is the position of ship navigation and positioning techniques based on the observation of the stars and other celestial bodies. The measured variables to find the situation are the observed angular height of the stars on the horizon, measured with the sextant (formerly with the astrolabe or other instrument), and time as measured with the stopwatch.

Conceptually, the process is not complex to understand. Knowing the time of observation, and the data in the Nautical Almanac, it is possible to determine the coordinates of the star observed astronomical. Knowing the coordinates of the observed body and the height above the horizon, it was observed, we can infer that the position of the observer is located on a circle whose center is located in the geographical point directly under the sun. Any observer at any point on that circle the star observed with the same height above the horizon. The observer can know, therefore, that their position is somewhere on this circle.

In practice, the mathematical process called “reduction” of observation, can be complex for the uninitiated. At the height observed with the sextant, it is necessary to apply a number of corrections to compensate for atmospheric refraction, parallax and other errors. Once done, you need to solve mathematical and trigonometric methods a spherical triangle. There are many methods to do this. Manual methods use tables (trigonometric, logarithmic, etc..) To facilitate calculations. The emergence in the late twentieth century, calculators and electronic computers, greatly facilitated the calculation, but the appearance of GPS downplayed celestial navigation, relegating it to the background as an alternative in case of failure of the electronic on board or as a hobby of scientific interest.

The nautical mile is a unit of length used in sea and air. Currently, international definition, adopted in 1929, is the conventional value of 1852 m, which is about the length of an arc of 1 ‘(one minute sixtieth of a degree) of meridian. It was introduced in the nautical centuries, and was adopted, with very slight variations, by all countries occidentales.1 Its use is supported in the International System (SI).

There is no single universally accepted symbol. The SI gives preference to M, but also used mn, nmi, NM and Nm (English: Nautical Mile) .2 Not to be confused with the statutory or English mile is still used in some common law countries and amounts to 1609.344 m.3

The nautical mile and knot are practically the only speed and distance measures used in sea and air, as they simplify calculations observer position. This position is measured by the geographical coordinates of latitude (North or South) and longitude (East or West) from Ecuador and a reference meridian, using degrees. The problem of the navigator is to know the position in degrees and minutes of latitude and longitude after traveling a certain distance, or vice versa, knowing the current coordinates and the destination point, calculate the distance at which it is located. Using nautical mile, each unit of distance equal to one minute of arc (1/60 of a degree) above Earth’s surface, and then is passed to determine the new position.

The letters, the paths (and many land maps) allow to know the coordinates of headlights, headlands, islands, etc., easily calculating the position using trigonometry. In the open sea the sextant is used to deduce the height observed position of the stars relative to the horizon, with convergence around the minute of arc of latitude and longitude. In modern times, the use of GPS has spread the knowledge of the coordinates of latitude and longitude with great accuracy.
Note

A key mnemonic to learn the value of the nautical mile is: A free eight cubits (1,852 km = 1 Nm).