WiMAX technology

Wi-Max or global operational structure to cross the microwave is a modern communication technology aims to provide evidence Wireless "Wireless" over long distances through the cell phone is compatible with the standard IEEE 802.16 world record or WirelessMAN. WiMAX

Name came from naming WiMAX Forum WiMAX, which took place in 2001, which concluded that the identification and definition of this technique as a technique based on a standard plug that allows wireless access to this large-scale and replace digital cable DSL

There are two types of Wi-Max ..

WiMAX fixed .. Where the client machine receives the signal from a fixed place, whether at home or the office. And present two forms of the capture device in the internal surfaces of the building or near windows

Mobile WiMAX .. Where the user can move from one place to another during the browsing and use of the Internet.

WiMAX's advantages

Provide high speed through the central stations WiMAX-related centers, Wi-Fi connection in the big cities without the need for an area of ​​direct or straight line between sender and receiver

Not affected by buildings or natural barriers between the central transmitters and receivers.

WiMAX technology enables the exchange of media (information, voice, image) between the users at high speeds of up to 280 Mbps 280 Mbps.

WiMAX technology allows the exploitation of frequency transmission channels efficiently. Through the frequency re-use of these channels, which increases the capacity of cells to communicate with the growth of the network and this in turn can increase the number of subscribers.

Designed frequencies in the Wi-Max, ranging from single user up to 100 channels, each channel of the frequency channels of communication where the start frequency of 1.75 MHz 1.75 MHz to 20 MHz 20 MHz.

WiMAX is designed to give high speeds in all environments, whether the transmitters and receivers on the direction of direct or indirect guidance. Has reached the distance between the transmitter and receiver up to 70 miles at speeds of up to 70 Mbps in a single transmission channel, using the techniques of smart antennas and networks of random tracks.

Purification process the way (WiMAX) work the same way (WiFi),

But more than speed and space is very large

Definition of the radar

Radar stands for the word Ring Radio means radio waves ring

Definition of the radar
Radar electronic system used to detect moving targets or fixed and location. Can determine the direction of radar targets far from the vision of the human eye, as well as determine the distance and height, as it can find the objectives of small insects, or the enormity of the mountains. The radar works efficiently at night, even in dense fog, rain or snow.
Radar and scalability of the implementation of several tasks to make it useful for different purposes and wide; depend on the radar for pilots landing their aircraft safely in crowded airports, as used by navigators in bad weather to drive their ships near the boats and dangerous goals. And uses a lot of countries of the radar guard from sudden attacks of the enemy planes and missiles, and can be employed weather radar to track air approaching storms. Scientists use radar to investigate the Earth's atmosphere above, and also use it to study other planets and moons.

The device operates almost all radar-mediated send radio waves toward the target, and receiving waves reflected from it. Indicates the time it takes for the reflected waves to return over the target and how far?, In addition to the direction in which it waves reflected back on the position of the target.


Different radars in size and shape, but they are all essential parts of one; and each transmitter device for the production of radar signals, and an antenna for broadcast abroad, and brings together the same antenna in most types of radar waves back from the target. And strengthens the future reflected waves which are called resonances that can be seen on the screen. Similar to the radar screen picture tube in your TV, but they are often circular rather than rectangular. Show points of light echoes, or imagination of the target viewer.

History of radar
In 1904 invented the German scientist Christian Holsmier simple device that uses radio beams to prevent ships from hitting each other in the seas, and in 1922 appeared the first system to a long-range radio at the hands of the Italian Guglielmo Marconi the world.

Christian Hulsmeyer   

Uses radar

Based air traffic control centers on the radar to track and guide aircraft in flight between airports. Shows radar waves reflected from the planes illuminated points on a circular screen. The flight path can be specified for each aircraft movements follow-up points. In air navigation. Radar is an important tool in navigation. The shares used in all airports and aircraft to a large extent in the safety of navigation.

It is known that the air traffic near large airports are quite dense, so it is used monitors traffic coaches radar at all airports in the world's major to guide the continuous flow of aircraft arriving and departing; it shows the radar monitors the subject of each aircraft in the air in a minimum of 80 km from the airport. And enable this information to prevent collisions by choosing the most appropriate paths to be followed by pilots. Observers also depends on the radar for them to guide the landing ground when bad weather, when a vision becomes the pilots of the lights and they approached the stands during difficult.

And defines a system called secondary radar, the aircraft on the screens of observers in the air traffic. Vtbos wireless signal transmitter on the plane, sends signal cryptographic due, containing the aircraft call sign. And this reference painted on the screen next to the point that represents the plane.

And most modern aircraft of different types of radars to help the pilot. For example, a radar altimeter shows the amount of altitude in the aircraft in flight, and so helps to keep the pilots at a convenient height. There is another way, is the weather radar that detects nearby storms, so pilots can change the tracks to avoid bad weather as they could.

In maritime navigation. Radar is used widely as an assistant for navigation in many types of boats and ships, from cruise vehicle, small to large oil tankers. A radar ship in bad weather conditions to locate other ships, rocks and snowy mountains at the appropriate times to avoid accidents. The navigator can, when the ship near the shore, to locate the ship's radar echoes of the mediation of private floating reflectors, or islands, or signs of other land.

Is used for port officials to control the radar ships in the busy port. They track the movement of all ships in the harbor on the radar screen that gives a kind of image map of the port. And mediated by the Radiocommunication these officials can guide the ships entering and leaving the harbor safely in any weather conditions.

Stations can also track the effects of Coast Guard vessels from the radar observations, and the Coast Guard used radar to search for the ships of the Code and reported as lost.

In the armed forces. Radar uses a wide variety in the armed forces, including the following main applications:

1 - Air Defense

2 - missile defense

3 - space surveillance

4 - poll

5 - measuring range

6 - control arms fire.

Space surveillance radars include the use of superior ability to detect and track satellites, as well as any other targets placed in orbit around the Earth. For this purpose, to invest the United States and Canada called the network system of detection and prosecution space. The system includes three facilities for a missile defense system, and eight other facilities in different locations of the world. He believes this system about 20,000 daily monitoring of hundreds of tropical goals (which revolves around the earth). And help the data received from these observations to identify the satellites used for reconnaissance spy.

Mapping radar contact can be made from an aircraft, this radar map of the city of Flagstaff in Arizona, USA, (right), taken from the height of 12.000 m and show pictures of the city Kaancod yellow. The shape of the land mass to the left of the city is Mount Elden.

Poll - the compilation of information. Radar is used to collect information on the preparations being taken by other countries for the war. Can radar mapping mobile in the plane to produce detailed maps of the Earth, and shows of military installations and equipment. And can other types of radars to obtain important information on missile systems to another country to monitor its missiles during tests at all.

Measurement range. Often used to check the radar range to ensure the performance of military equipment. For example, radar can measure the extent to accurately track the missile flight again. If this is not the performance of the rocket as expected, it can be to trace data that helps the designer to determine the error.

To control traffic speed and flow. Police use radar in some countries to apply the laws of speed and make sure the speed of vehicles on streets and highways. The police radar devices can detect moving vehicles accelerated from about 370 m. And radar signals transmitted from the antenna outside the vehicle the police compound.

How does the radar

How does the radar pulse

Different groups in radar design and purpose, but they all work on the same general principles. And produces all radar and broadcast signals in the form of electromagnetic waves. The radar waves can be radio waves or light waves. And most groups of the radar transmitted radio waves, but few of them are called optical radar or laser radar waves transmitted light.

When you send a group of radio-wave radar waves hit this goal is reflected, and returns a section of the reflected waves to the radar set on the track himself, who sent it. This is similar to reflection, to a large extent, what happens when a person screaming in the mountain valley, heard his cry echoed from the rocks nearby. In this case the reflected sound waves instead of radio waves or light.

The radar waves sent by a specific frequency. The frequency is measured in such a wave is called the unity of MHz. Equal to unity Almijahrtz million hertz (cycle per second). For the waves of radio frequencies for low-frequency light waves, and most of the radars that broadcast on the radio waves operating at frequencies between 1,000 MHz and 50,000 MHz. And optical radars operate at frequencies much higher, and some wavelengths of light are born with frequencies up to a billion MHz.

The groups are designed radars, in many cases, for different purposes and operate at different frequencies. The radars are operating at low frequencies is more effective than those operating at high frequencies to penetrate clouds, fog and rain, so widely used in aircraft and ships. On the other hand gives the radar high frequency, accurate measurements and smaller antennas than those used in low-frequency radars. Optical radar, for example, produce a signal with a very narrow beam from a laser with a diameter of only 1.3 cm. Optical and radar are particularly useful in difficult terrain survey, where you must measure the distant points through the gaps between things big rocks and trees.

The groups vary in how well the radar signals, and are classified on this basis to the two general types, namely:

A radar pulse is the most common

Broadcast signals in the form of intermittent bursts of strong, or impulses, and will continue to wave radar pulses a few millionths of a second. And a set pulse radar antenna and the one used to send pulses alternately and receive repercussions.

Can find the distance to one of the objectives measured the time it takes the wave radar to reach this goal and back. The radar waves travel like the rest of electromagnetic waves at light speed 299.792 km / s. So Valmujh radar return after two seconds, which may be made 599.584 km, 299.792 km in any Go to the goal and the same distance in the second leg, turning the pulse radar automatically set the time required to go and return to a distance of (yet) toward the goal.

The broadcast antenna wave pulses in highly directional narrow beam enables a radar to determine the direction of the target. Waves can not reverse unless the target is located in the packet size only. And determines the direction in which waves are reflected from it into the goal. Pulsed Radar can pursue (follow) the goal, sending a continuous pulsed signals, and measure the distance and direction of the target at regular intervals. It uses this type of radar also for mapping radar from an airplane. The map can be produced pulses of radar scans the package on an area-specific, and draw the intensity of echoes from every direction. The echoes appear in the form of an image on the radar screen, and recorded on a film projector. And produces goals, such as buildings, bridges, mountains, pictures of shiny, because it reflects the strong echoes.

2 continuous wave radar

Broadcasts a continuous signal, rather than short bursts, and there are two types of continuous-wave radar, are:

A Doppler radar

2 radar frequency modulation.

Doppler radar has mainly been used for accurate measurements of speed, and works on the principle of the Doppler effect, a change in frequency caused by the movement. Doppler radar sends a continuous wave frequency is fixed, and uses the same antenna in both transmission and reception. When the transmitted wave to hit the oncoming of the radar, the reflected waves with a frequency higher than the frequency sender. And when the target away from the radar set, the counter-wave frequency becomes less, and the more objective was faster in either direction difference was even greater between the frequency of sending and frequency of the reflected wave. By measuring the difference in the frequency Doppler radar sets the target speed observer.

And the police use Doppler radar to detect speeders drivers. The soldiers used to measure the speed of goals to guide arms fire.

Radar frequency modulation signal is also transmitted continuously, but it increased or decreased frequency signal at regular intervals. As a result, the radar frequency modulation, in contrast to Doppler radar, can determine the distance to the goal of a fixed or mobile. At the time it reaches the radar signal to the target and return, the frequency of the sender's goal has changed. The measured frequency difference between resonance frequency and the sender, and converted to a distance of the target, which produces the echo. As the goal was increased beyond the difference between the frequencies.

Can be used radar frequency modulation, such as radar pulse, in the mapping, and in the prosecution. It can be used on aircraft altimeter.

Sections of the radar range

Varies depending on the size of a radar use; The group of radar used by police to detect speeding cars nearby, can be carried by hand, and weighs about 18 kg. The huge radar units used to study the planets and other distant targets, include large buildings. Some of these units to antennas with a diameter of 300 m.

In spite of the different groups radar are similar in size in the subdivision, and these sections are:

1 - Oscillator:

Device produces an electrical signal with a capacity of low-frequency constant. Specifies the frequency oscillator frequency radar working group.

2 - included:

In the pulse radar, electronic key, connect the sender and separated quickly. Thus, the sender produces short-wave bursts. At the radar frequency modulation changes the built-in wave sent down. And no Doppler radar is included.

3 - the sender:

Serves as the speakers, it takes the electrical signal with a low capacity, and produces high-power signal. For example, produces pulse radar transmitter, the user in control of air navigation, the ability of signal maximum of up to several million watts.

4 - the key to the transmission and reception:

You can use a single antenna for both transmission and reception. And leads key transmission and reception signals sent to the antenna, and prevents the flow of these signals to the future. And strong signals from the sender that may damage the future if it involves sensitive. After sending a wave of the antenna Aousel key transmission and reception, the antenna to the future. And such a connection can pick up echoes of the future to come.

5 - Antenna:

Large dish antenna rotor is used in the radar stations on the line of distant early warning, and wipe the reflectors that work automatically the sky, for the detection of enemy aircraft. The antenna. Sends radar signals in the form of narrow beam of electromagnetic waves, and combines the reflected echoes. As the most modern radar units have a key to send and receive, they use the same antenna for transmission and reception.

It consists of the common type of horn antennas attached at the top of a large reflector dish is called reflecting. Is called the trumpet-band radar, Verzha in narrow beam reflector. The radar antenna is going, so spread this package on the radar scanner targets in all directions.

The groups used in other types of radar antennas operating at lower frequencies or at frequencies too high. It uses radar, which broadcasts radio waves low-frequency antennas are made of metal tubes, rods or similar external antennas for TV. And are used in optical radar, a markedly different device sends high-frequency waves Kaldu ultraviolet or visible light or infrared. This is similar to the means and the telescope (the telescope) and has a glass lens focuses waves emerging in the package.

6 - the future:

Takes weak resonances mediated by the antenna and accumulated much magnified. And the future is so sensitive that it can easily detect echoes with a capacity of less than one millionth of a watt. And will nominate the future noise and other interference captured from the antenna.

7 - Signal Processor:

Pass the reference of the future, in most radar units, during the signal handler before she went to the screen. The lead signal processor and the different functions in the radars used for different purposes, it is obscure in some types of radar echoes from targets large and fixed, and only allows for the echoes from small targets moving up to the screen. And so can the radar signal processor factor, to see the plane, for example, although the echoes of the plane up at one time with a much stronger echoes coming from Mt. The computer in many modern radar signal processor serves.

8 - the viewer (the screen):

Provides for workers in the information obtained from the radar target. Some groups opposed the radar is simple. Fradarat Doppler phones used by the police, for example, have a scale refers to the speed a vehicle or truck, but most of the groups opposed the radar complex, consisting of a tube cathode rays, a vacuum tube fluorescent provider Viewer is similar to the TV. See: vacuum tube. The viewer can display cathode ray tube of radar data in many forms.

And the viewer is the most common index position opposed surface, and gives us a similar map of the area scanned radar beam. And agrees center of the image position of the radar set. And the area around the viewer is included, such as the compass in order to read the direction. And can be opposed to the circles spread from the center of the image to the surroundings to show the distance in miles or km. Show radar echoes in the form of bright spots. And gives the position of the point scale for the compass direction of the target. Shows distance from the center point of the screen after the target amount. It can determine the speed of the target by observing the time it takes to go a point a certain distance Viewer radar.

Show symptoms of other forms of high goal, and uses this type of radar beams in groups designed to help guide the aircraft during landing.

9 - Timer:

Believe play a radar efficiently and easily. And reached this Alnbith main parts to a radar accurately and separated in time automatically, and the timer is doing this by sending control signals to the various sections of the appropriate sequence.

Symbols of the digital gates

Reading of the resistance

camera triax cable

Semi-Conductors

Divided materials into conductive materials with a resistance less than the quality of ρ a certain extent and insulating material resistant quality of ρ higher than a certain value, and between them a region where ρ which do not fit conductivity and insulation, so called semiconductors. Do not use the term "semiconductors" because half the number of value and has a half connector will connect the copper conductor as well.

What is the most appropriate definition then?

If we take the former division of the atomic structure, where we will determine a good definition for semiconductors. The following very important to understand the different kinds of semiconductors because many confuse the type C or N, and being a negative or neutral, and likewise in the p-type or P.

Materials composed of molecules containing atoms. Each atom is composed of a nucleus by a number of positive protons and neutrons are neutral, the number of protons determines the element and its properties as there is no two elements have the same number.

Represents the number of protons a positive charge, and must for this shipment to be equally Vtgzb the negative electrons revolve around the nucleus in the tracks and each track has a specific number of electrons does not change with the exception of the final orbit farthest from the nucleus.

This final orbit can accommodate eight electrons only, but the number of protons may not attract enough to complete this final orbit, this situation creates instability of the noted, you want to complete the orbit the outside to contain eight electrons do not want to increase the negative charge on the positive charge, did not God create electrons neutral! ! So what's the solution?

Solution that the atoms are linked together, how?!! Well, to look for the installation

Wants to orbit the last eight electrons for this magical figure is half, or 4

?What is this magic number

Atom linked with four surrounding atoms together so that every electron of this atom is associated with an electron from a neighboring atom Vkonhma orbiting in the orbit of the atom together and that each atom together Vtkon atoms as if the outer orbit complete with eight electrons.

We note here two types of link

Chemical link a parity quartet and completed to achieve 8 electrons in the outer orbit.

Electrical connection and achieve that the number of electrons equal to the number of protons and there is excess shipments.

Result of the close link between the electrons and the nucleus, we do not find many free electrons that cause a flow of current.

Examples of pure carbon and pure germanium and pure silicon Silicon.

?So what do we do to increase the conductivity

The solution is simply to add a bit of a bug, do not mean inferior materials, but we mean the other elements.

Ah, then these elements are reached by the current in the semiconducting material!!

No.

So why this suffering and we have the best metals like copper, all of them.

The idea that we are not trying to connect, but we seek to create an imbalance in the training prepares us to seize it in this big world - a world of semiconductors.

If we put a little bit of pentavalent element - this means that the orbit of the five outer electrons. So four of them will be involved with the silicon atoms as has been and remains the fifth without a link.

Note here imbalance incident, this electron can not stay because you do not link him with the neighboring      !!atom. Well for the proceeding of the state of him

!Where a restricted proceeding proton in the corresponding positive Dhirth

Position a little weird, but with great interest. This electron movement is free but you must come to be equally replacement shipments atoms and thus we have the possibility of transferring the power of these free electrons and for this article called "negative" and that was not a negative voltage or charge transfer, but what is the current negative electrons.

Remember this very well that the electrically neutral material but it has many free electrons are subject to movement. This means that the mediator for the transfer of power is negatively charged electrons.

Now what if we trivalent material? Remember that the trivalent concerned with the outer orbit contains three atoms.

The same case except that we have now three electrons only, and this will create a strange situation as well.

Associated with the three electrons in three neighboring atoms and the fourth will not find an electron to achieve a valence bond. But the electric equalizer investigator.

This will create a shortage or gap or place can be any electron transient fall in which to achieve their link equity, but, when this happens be destroyed tie electrophoresis and become negative charges than positive, this can be for this electron to voice, moving to an atom neighboring the gap as well, which seems as if I moved the gap in the anti, and emphasize what seems to go because of the electron is actually a particle with a mass which can be found in the case of separate and move in a vacuum but there is no body of his name and there is no gap in the vacuum and there is no outside of this atomic configuration.
To facilitate dialogue, scholars viewed the gap is positive because it will attract negative electron and the electron is moving the opposite taking into account that the exact detail is understood and called the article a positive P m on the grounds that the gaps are the carrier stream metaphor.
The issue is like when we sell a property is in debt by saying the debt is transferred from X to Y while in truth what is the money moved from AM to Q.

Conclude from the above the fact that always move in the current Article X or N is faster than moving in Article M or P and the reason that the transfer of an electron directly from the atom to another, will always move faster than the gap and drawing the other hand explains why.

Can you find the motion of the electron or the way the Supreme faster transmission of the gap and then move to the next gap and then the new Next Valtaly!!

?Now what happens if and docked two links m and Q or P, N together

Optical fibers

A wire of pure glass is thin - such paper human hair - carry digital information over long distances. Installation of fiber optic

We have stated that fiber-optic cables are thin and long line of pure glass and arranged in bundles called optical cables (Optical Cables) to be used in the transfer of light signals to great distances. If we take a closer look closely for a fiber-optic'll see it consists of the following parts:

1  -the heart or core (Core): a center fabric (fiber) and transmitted light through it 

  2 - Cover (Cladding): a substance foreign to the surrounding tissue and the heart and mission to reflect the light outside of the heart and return it to him.

  3 - protective cover (Buffer Coating): It is a plastic cover, and its mission to protect the optical tissue damage and moisture. Hundreds of thousands of these optical fibers arranged in bundles in the form of optical cables. These packages are protected by the outer casing of the cable is called Cover (Jacket).

Optical fiber is divided into two basic types

1 - Single-fiber-type (Single-Mode Fiber). Heart and be of small diameter up to 9 microns, signals and transmits infrared laser with a wavelength range between 1300 to 1550 nm.

2 - fiber multi-mode (Multi-Mode Fiber).

This is where the heart is a larger diameter of up to 62.5 microns, and the carry and transmit signals by infrared diameter ranges between 850 to 1300 nm, and electronic valves made ​​of light-emitting (Light Emitting Diodes LED). Some fibers can be made ​​of plastic, but the basis of the (Core) with a diameter relatively large (1 mm), and suitable for light transmission, which can be seen just which wavelength greater than 650 nm, the light emitted from the LED mail (LED) does not fit this type of fiber for the transfer of laser light (emitted from a laser-firing). Here we can wonder how these fibers can be transferred Alduualmalomat digital.

How do optical fibers

Suppose we want to send bundles of light rays through a path, we can draw so that the light through this path as the light travels through the straight lines. Problem that can Tsadvina If this is the path contains a turning point, what can be done in such a situation? Solution to put a mirror at the point of inflexion (Bending) that in order to reflect light at this corner and return to the track. How if the path contains many turning points? In this case we need a mirror at every turn, and placed the mirror at an angle to allow the return of light to the heart at each corner along the route. This is exactly what is happening inside the optical fiber. Valdu travels through the core (path) with leaps regular cover (mirror) at the turning points by the so-called reversal total internal (Total Internal Reflection), and because the atmosphere does not absorb any of the signals of mobile inside the heart, the light signals can be transmitted over long distances . But some of these signals weaken within the fiber because of the purity of glass contamination for example, and the extent to which can be weakened when these signals depends on the degree of purity of the glass, which made him fibers and also supports the wavelength of the light sent through it (for example, 850 nm weakens by about 60 to 75 percent per kilometers) and some fibers weaken the signal by less (10% per km at 1550 nm wavelength).

Communication system via fiber-optic system consists of the following elements:

Transmitter (Transmitter): The reception and guidance of the light source device (LASER or LED) and run it on and off according to the correct sequence, and thus the optical signal is generated. And the transmitter is close to the optical fiber and may contain lenses (focused lens) in order to collect and focus light in the tissue Baraa photosynthesis. Laser light has a greater power than possessed by light from the LED emitter, but more sensitive to changes in temperature, as it is more expensive. Optical fiber (Fiber Optics) an environment of communication between sender and receiver. A regeneration signal (Optical Regenerator): we noted in the above cause some loss in signal (Signal Loss) when transmitted light within the fiber over long distances - as is happening inside the submarine cables - and this reached a tonic and organs regenerate the signal along the cable in order to enhance weak signals. And consists of the device from the optical fiber with a special coverage inlaid (doping), and works of this section of the fiber pump laser (pump); When you reach the weak signal to this section, the laser energy here makes the molecules traffic light work as if it were the source of the laser, whereupon the firing signals new light, strong, but with the same characteristics of the weak signal coming. This means that this device works as if it were a laser amplifier for the signal coming to it. The receiver (Optical Receiver): takes the signal optical digital and decoded, and sends electrical signal to the user was either a computer or cable TV or phone. The receiver contains optical light cells (photocells) an electronic or optical valves (photodiode) and notes to be sensitive to the traffic light. Advantage of optical fiber (Advantages) of what caused the optical fiber technology revolution in the world of communication, compared with other conventional wire - copper wire, for example?

Reason appears in the following points:

1. Relatively low cost.

2. Paper and the accuracy of the fiber. This leads to ..

- The ability to transport high (Higher carrying capacity) because of the paper fibers, many of which can be packed inside a cable with a diameter more than if the copper wires in the cable has the same diameter, which means a greater number of telephone lines connected or if the available TV channels We were talking about the cable TV system. - It has less in the signal. - Carries light signals. Unlike copper wires that carry electrical signals, optical signals do not overlap (interference) between them, which means phone calls or television reception clearer. - The ability of a lower transmission (Low Power). - Digital signals (Digital Signal). Optical fiber is designed primarily for the transfer of digital signals, and this is especially useful in computer networks or the Internet. - Non-flammable. Due to lack of passage of electric current in it, there is no risk of burning. - Lighter weight (lightweight). Compared with copper wire. And occupy less space when you pass beneath the surface of the earth. - Flexible (flexible). Because of their flexibility and high sending and receiving of the light they are used in many of the cameras digital for the purposes of theorizing Medical (Medical Imaging), inspection and the work of welding inside the pipes and engines Mickey **** Ye difficult to access in planes, cars, rockets, as used in plumbing pipes and narrow scanned . - How to create a fiber optic? Already mentioned that the main material in the manufacture of glass are - which is the primary source of sand for him - given the many details in this brief, we shall see. Industry traffic fiber optic require several stages:

At first the work cylinder glass by a process of sedimentation Bukhari chemical average (Modified Chemical Vapor Deposition) is a complex process carried out under high temperature and conditions of special chemical, and where the interaction of chloride silicon Sicl4 and chloride germanium Gecl4 bubbles with oxygen, to produce a silicon dioxide Sio2 and oxide, germanium Geo2 who Ijmaa Ivaba together and inside the pipes to form a glass fiber or material. And then is pulled in the form of wires, high and long in areas like lathes (Lathe) and be very private and accurate, called towers pull Fiber (Fiber Drawing Tower) and the fiber is covered with a layer of plastic to protect them. Then be examined fiber from several aspects such as: tensile strength, regularity of Qatar heart and the dimensions of the covers of protection, the vulnerability of the signal with the increase in length, the bandwidth (bandwidth), operating temperature and the humidity, and they relate to weak signal, and finally the conductivity under water.

Satellite

In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon.

The world's first artificial satellite, the Sputnik 1, was launched by the Soviet Union in 1957. Since then, thousands of satellites have been launched into orbit around the Earth; also some satellites, notably space stations, have been launched in parts and assembled in orbit. Artificial satellites originate from more than 50 countries and have used the satellite launching capabilities of ten nations. A few hundred satellites are currently operational, whereas thousands of unused satellites and satellite fragments orbit the Earth as space debris. A few space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Mercury, Venus, Mars, Jupiter, Saturn, and the Sun.

Satellites are used for a large number of purposes. Common types include military and civilian Earth observation satellites,communications satellites, navigation satellites, weather satellites, and research satellites. Space stations and humanspacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways. Well-known (overlapping) classes include low Earth orbit, polar orbit, and geostationary orbit.

Satellites are usually semi-independent computer-controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control and orbit control.

Types

• Anti-Satellite weapons/"Killer Satellites" are satellites that are designed to destroy enemy warheads, satellites, other space assets.
• Astronomical satellites are satellites used for observation of distant planets, galaxies, and other outer space objects.
• Biosatellites are satellites designed to carry living organisms, generally for scientific experimentation.
• Communications satellites are satellites stationed in space for the purpose of telecommunications. Modern communications satellites typically use geosynchronous orbits, Molniya orbits or Low Earth orbits.
• Miniaturized satellites are satellites of unusually low masses and small sizes.^[13] New classifications are used to categorize these satellites: minisatellite (500–100 kg), microsatellite (below 100 kg), nanosatellite (below 10 kg).
• Navigational satellites are satellites which use radio time signals transmitted to enable mobile receivers on the ground to determine their exact location. The relatively clear line of sight between the satellites and receivers on the ground, combined with ever-improving electronics, allows satellite navigation systems to measure location to accuracies on the order of a few meters in real time.
• Reconnaissance satellites are Earth observation satellite or communications satellite deployed for military or intelligenceapplications. Very little is known about the full power of these satellites, as governments who operate them usually keep information pertaining to their reconnaissance satellites classified.
• Earth observation satellites are satellites intended for non-military uses such as environmental monitoring, meteorology, map making etc. (See especially Earth Observing System.)
• Tether satellites are satellites which are connected to another satellite by a thin cable called a tether.
• Weather satellites are primarily used to monitor Earth's weather and climate.^[14]
• Recovery satellites are satellites that provides a recovery of reconnaissance, biological, space-production and other payloads from orbit to Earth.
• Manned spacecraft (spaceships) are large satellites able for put human into (and beyond) an orbit, being on it and recovery back to Earth. Spacecrafts, and orbital parts-spaceplanes of reusable systems also, has a major propulsion or landing facilities, and often uses as transport to and from the orbital stations.
• Space stations are man-made orbital structures that are designed for human beings to live on in outer space. A space station is distinguished from other manned spacecraft by its lack of major propulsion or landing facilities. Space stations are designed for medium-term living in orbit, for periods of weeks, months, or even years.