wi-fi, blutooth,gps,gis

8/8/2019 Wi-fi, blutooth,gps,gis

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Explain the input devices?

Input devices are used to capture the data and transmit it to thecomputer system for further processing and in computer readable

form. Some of the input devices are as under.

Keyboard Devices:

Keyboard devices are the most commonly used devicestoday.

They are used for data entry into a computer system bypressing a set of keys, which is connected to a computersystem.

Programs and data are entered into a computerthrough a keyboard.

A keyboard is similar to a typewriter it containsAlphabets, digits, special charters and some controlkeys.

When a key is pressed an electrical signal is producedwhich is detected by an electronic circuit called keyboardencoder.

Its functionis to detect which key has been pressed andsend binary code for it.

What is scanner?

Data scanning devices are input devices, which are used

for direct entry into the computer system from source

documents. Data Scanning Devices are of many types:

Image Scanner: An Image scanner is an input device, Which translates paper documents into an electronic


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format Which can be stored in a computer The Input document may be text, pictures and even

handwritten material.

The copy of a document stored in a computer and can bedisplayed or printed whenever desired.

Two common used types are:

Flatbed Scanner:

A Flatbed Scanner is like a copy machine, which consists

ofbox having glass plate on the top. The document to be scanned is placed upside down on

the glass plate the light is below the glass plate and moveshorizontally from left to right when activated.

After scanning one line the light beam moves up alittle and scans a next line.

This process is repeated for all the lines.

Hand-held scanner:

A Hand-held scanner to scan a document, the scanner isslowly dragged from one end of the document to

its other end with its lights on. The scanner has to be dragged very carefully over the

document.

Otherwise the conversion of the document into its equivalent

bitmap will not be correct due to this reason hand-heldscanners are used only in cases where high accuracy is notneeded.

They also much cheaper as compared to flatbed scanners. When image scanners are used for inputting text documents,

they have the following limitations:


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Input document is stored as an image, instead oftext. The computer can't interpret the stored document asnumbers characters and special symbols. The storage required for storing the documents

as an image is much more than that required forstoring the same document as a text.

Point-and-Draw Devices:

Mouse:

Mouse is the most popular point-and-draw device today.

A mouse is also called a pointing device.

It moves across a flat surface with the help of tracking balls.

Its movement and the direction of the movement are detected by two

rotating wheels on the underside of the mouse called sensors.

Light Pen:

A Light pen is a pointing device. It is used to select and write the text on the CRT. It

is capable of sensing a position on the CRT screen when its tip touches the screen.

Joystick:

A Joystick is also a pointing device.

It is used to move the cursor position on the CRT screen.

Its function is similar to that of a mouse.

It is a stick which has spherical ball at its lower-end as well as its

upper-end.

The lower spherical ball moves a socket.

The joystick can be moved right or left, forward and backward.

Mainly used in playing 3D games.

On most joysticks, a button on the top is provided to select the option.

Touch Screen:

A Touch screen enables the users to choose from available options by simply

touching with their fingers the desired icon or menu displayed on

the computer screen.

Touch screens are mostly preferred human-computer interface devices


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used in information kiosks.

Which is used to store information of public interests

Allows common people to access the stored information as per their

requirements?

Example:

At an Airport or a railway station to provide information to arriving

passengers about hotels, tourist sports etc. in the city.

In large museums it guides about various attractions and facilities.

OCR (Optical Character Reader):

The OCR technology is used to overcome these limitations.

In this, the scanner is equipped with character reorganization software called

OCR software. This software first creates the bitmap image of the document

and then the OCR software translates it into ASCII text, which the computer

can interpret as letters, numbers and special characters.

If the document contains Italics or Boldface letters or fonts other than that for

which the OCR software has been designed, the OCR software will not work

efficiently.

Output Devices:

An output device accepts data from a computer and translates them into a form,

which is suitable for use by the outside world. Output devices can be broadly

classified into the following categories:

1. Monitors

1. Printers

2. Plotters

3. Screen Image Projector

4. Voice Response Systems

1. Monitors:

Monitors are the most popular output devices used today for


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producing soft-copy output.

A monitor is usually used with a keyboard, and together they form

video display terminals (VDT).

It serves as both input/output devices. The two basic types of monitors

are Cathode-ray-tube (CRT) and flat-panel.

The CRT monitors look much like a television; on the other hand, the

flat panel monitors are thinner and lighter and are commonly used with

portable computer systems like notebook computers.

Printers:

Printers are the most commonly used output devices for producinghard-copy output. The various types of printers are:

Dot-Matrix Printers:

Dot-Matrix printers are character printers, which printone character

at a time.

They print the characters and all kinds of images as apattern of

dots.

A dot-matrix printer has a print head, which can move horizontallyacross the paper.

The print head contains an array of pins, which can be activated

independent of each other and strike against an inked ribbonto

form a patter of dots on the paper.

To print a character, the printer activates the appropriate set of pins as

the print head moves horizontally.

Dot-Matrix printers are impact printers because they print by

hammering the pins on the inked ribbon to leave ink impressions onthe paper.

Due to impact printing, dot-matrix printers are noisy as compared to

non-impact printers.

Dot-matrix printers are normally slow with speeds ranging

between 30 to 600 characters per second.


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Ink jet Printers:

Ink jet printers are character printers, which form characters and all kinds

of images by spraying small drops of ink on to the paper.

The print head of an ink jet printer has 64 tiny nozzles,

When the register heats up, the ink near it vaporizes, and is ejected through

the nozzle, and makes a dot on the paper placed in front of the print head.

To printa character, the printer selectively heats the appropriate set of

nozzles as the print head moves horizontally.

Inkjet printers produce higher quality output than dot-matrix printers.

Inkjet printers produce printed output as patterns of tiny dots.

They can print any shape of characters which a programmer can

describe.

Inkjet printers can not be used to produce multiple copies of a

document in a single printing.

Inkjet printers are slower than dot-matrix printers with speeds ranging

between 40 to 300 characters per second.

An Inkjet printer is more expensive than a dot-matrix printer. Costly.

Drum Printers:

Drum printers are line printers, which print one line at a time.

It has solid drum with characters embossed on its surface in the form of

circular bands. Each band consists of all the printing characters supported by the printer in

its character set.

The printer has a set of hammers mounted in front of the drum in a

manner that an inked ribbon and paper can be placed between the

hammers and the drum.

The drum rotates at the high speed and a character at a print

position is printed by activating the appropriate hammer.

The drum of a printer is expensive and can't be changed often. Costly.

Typical speed of drum printers is in the range of 300 to 2000 lines per

minute.

Laser Printers:

Laser printers are page printers, which print one page at a time.

The main components of a laser printer are a laser beam source.

To print a page of output the laser beam is focused on the electro statically


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charged drum by the multi sided mirror.

It uses the electro static charging technique.

The mirror focuses the laser beam on the surface of the drum in a manner to

create the patterns of the characters/images to be printed on the page.

Laser beam move on the drum with the paper and the character and

the images will be printed on the paper.

The toner then permanently fused on the paper with heat and pressure to

generate the printed output.

The drum is then rotated and cleaned with rubber blade to remove the toner

sticking to its surface to prepare the drum for the next page printing.

Laser printer produces very high quality output.

They have high resolution and because of their high resolution these printers

give excellent graphics art quality.

They can print any shape which a programmer can describe. Laser printers

can not be used to produce the multiple copies of a single document in a

single printing.

WI-FI

Introduction

Wireless Technology is an alternative to Wired Technology,

Which is commonly used, for connecting devices in wireless mode

Wi-Fi (Wireless Fidelity) is generally used to represent the IEEE

802.11 communications standard for Wireless Local Area Networks

(WLANs). Wi-Fi Network connects computers to each other, to the internet

and to the wired network.

What is Wi-Fi? Explain the Wi-Fi?


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Wi-Fi, which stands for wireless fidelity,

It is a wireless networking technology used across the globe.

Wi-Fi refers to any system that uses the 802.11 standard.

Wi-Fi technology uses radio for communication, typically operating

at a frequency of 2.4GHz.

In a Wi-Fi network, computers with Wi-Fi network cards connect

wirelessly to a wireless router.

The router is connected to the Internet by means of a modem,

typically a cable or DSL modem.

Range :

o A user within 200 feet or so (about 61 meters).

o New wi-fi technologies will extend range from 300 feet (91.5

meters) to 600 feet (183 meters) and more then that.

Advantages

Wi-Fi can make access publicly available at Wi-Fi hotspots. Where the

Wi-Fi device is placed.

Does not require regulatory approval for individual.

Wi-Fi network can support roaming.

Wi-Fi allows local area networkto deploy without wires for client

devices.

Wi-Fi works with no physical wired connection between sender

and receiver by using radio frequency.

It provides the Portability. Means you can walk any where with just

the hand set in your hand.

No physical media interference (no any physical device is

required.)

Easy installation.


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Provides a multi-user environment. Morethen one user can work

together.

Security Greater exposure to risks. No more possibility of the breaks

in the security.

Setup Cost Reduced cabling required

Flexibility Quick and easy to setup

Scalability Can be expanded with growth ( more number of

computer can be joined easily)

Freedom You can work from any location

o Dis- advantages.

Speed the speed is slower than cable.

Range Affected by various medium

- Travels best through open space

- Reduced by walls, glass, water, etc.( speed reduces

when this comes in between the devices.)

Weak Connection (problem of the connection.)

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GLOBAL POSITIONING SYSTEM

The Global Positioning System/GPS is a constellation of 24 well-spaced

satellites that orbit the Earth 11,000 miles and make it possible for people

with ground receivers to pinpoint their geographic location.

It is generally used for the tracking the things. For example dogs, children,

bus, train, aero -plane. Finding where they are. How fast they are

moving.


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How GPS System Works:

The satellites in space provide the ranging signals and data

messages to the user equipment.

The control segment maintains the satellites & tracks in space. It

looks to the satellites. And stay connected with it.

The control system monitors satellite health and signal integrity

(strength of the signal) and maintains the orbital configuration of the

satellites.

The control system monitors the health and the strength of the

signal.

Furthermore, the control system updates the satellite clock (corrects

the position of the satellite if there is any error in the position

of it.) Corrections as well as numerous other parameters essential to

determining user position, velocity, and time (PVT).

Its used for correction of the parameter to determine position,

velocity, and time.


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Lastly, the user receiver equipment performs the navigation,

timing or other related functions (e.g. surveying).

Uses of GPS Technology

Location- determining a basic position. ( it is used for the finding the

position of the any things such as the mobile, bus , children, dog )

Navigation - getting from one location to another. (It tells where the

object actually is.)

Tracking - monitoring the movement of people and things. ( for

example the speed of the car, airplanes )

Mapping- creating maps.

Timing - providing precise timing.

Application of GPS Technology

Motor bikers Now Have GPS Option 9 to protect it from theft.)

A GPS Wrist Watch ( sales force management) Aircraft Having GPS System ( managing the path of the air craft)

Real Time Train Predictive Arrival GPS System ( to find departure and

arrival of the bus and the train.)

BRTS buses are the Great example of the GPS system.

GPS Help Protect Your Children?

GPS System to Be Available in Children's Shoes

A GPS device for your dogs & pets

The system links to a GPS-enabled collar for your dog to which help us

to locate it.


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GPS APPLICATIONS:

Environment management

Boosting the gold-mining industries

Forestry and agriculture industry

Natural disasters management

Maritime and Waterways finding

Tele-communications

Infrastructure development

Educational research

Public health and safety

Traffic management#######################################

General purpose GISs perform seven tasks:

Input of data

Map making

Manipulation of data

File management

Query and analysis

Visualization of results

GIS Applications:

Health and services planning

It is used in the supply chain management

It is used in the Market Research.

It is used in Operations Management.

It is used in the Distribution and Retail Services.

It is used in the Information Services - Tourist & Tour Operators

Spatial Services Management Defense and Disaster


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Management

Spatial Services Management - Land & Utilities Planning &

Management& Many Others

It is possible to develop GIS that monitor, transmit, record andanalyze the movement of mobile agents such as vehicles, people or

animals. Virtual Reality GIS supports creation, manipulation and

exploration of earth places.

####################

Bluetooth

Bluetooth is the name of technology that is becomingcommercially available.

It promises to change the way use of machines. Mobiles and

laptops.

Bluetooth technology is a wireless short-range

communication system introduced to replace the cables

connecting portable electronic devices. (mobile laptops, pda)

Bluetooth is a developing, world wide, open, short-range

radio specification focused on communication between the Internet and

Net devices,

plus it defines communication protocols between devices and

computers

Bluetooth is a standard and communication protocol primarily

designed for low power consumption.

Communication within short range is possible via Bluetooth

(power-class-dependent: 1m, 10m, 100 ms).

How the connection is connected?

For making a connection, a Bluetooth follows two procedures:


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Inquiry (or Discovering) Procedure.

Paging (or Connecting) Procedure.

Inquiry (or Discovering) Procedure

Bluetooth enabled devices use the inquiry procedure todiscover nearby devices or to be discovered devices in their

locality.

A Bluetooth enabled devices that tries to find other nearby

devices is know as inquiry devices and actively send inquiry

request.

Bluetooth enabled devices in a piconet.

Piconet:- It is a network in which up to eight Bluetooth enabled

devices can be connected

These are Bluetooth enabled devices which do not use the

request concept, rather they are connected to each other once

configured.

These devices usually are not compatible with every Bluetooth

enabled devices.

Special Chip Configuration is required resulting in secure data

transmission.

Typical Bluetooth Networks


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Benefits of Bluetooth Technology

Global Availability. Bluetooth devices are available every where.

Ease of Use. It is easy to use them.

Globally Accepted Specification. It is having same type of the

commutation protocol world wide.

Range of Devices. Advantages for the short range of the

communication.

Secure Connections.

Applications of Bluetooth Technology

More prevalent applications of Bluetooth include:

Wireless control ofcommunication between a mobile phone

and hands-free headsets. This was one of the earliest

applications to become popular.

It is used for the communication between the mobile phone

and the hands free.


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Wireless networking between PCs in a confined space and where

little bandwidth is required.

It is wireless networking system. Used where the small

number data have to be transferred from one device to

another device.

Wireless communications with PC input and output devices,

the most common being the mouse, keyboard and printer.

Sending small advertisements from Bluetooth enabled advertising

hoardings to other, discoverable, Bluetooth devices.

It can be used for the small advertising in particular area.

Dial-up internet access on personal computer or PDA using a data-

capable mobile phone as a modem.

It is used for wire less connection between PDA.

It is used in place of the infrared.

Advantages of Bluetooth Technology

It is able to communicate with the LAN devices.

No cable will require. Wire less network type or system.

We can use it with standing in different room. Means the Waals are

not the problem as in the infrared.

Bluetooth isn't a line of sight and it provides ranges of up to 100

meters.

Bluetooth is also low power and low processing with an

overhead protocol.

Small battery powered device.

Bluetooth is a low-cost wireless technology.

Bluetooth can be easily integrated into your products

Although there are very few disadvantages, Bluetooth still remains

the best for short range wireless technology.


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Disadvantages of Bluetooth Technology

Infrared can have data rates of up to 4 Mbps, which provides very fast

rates for data transfer, while Bluetooth only offers 1 Mbps.

Smaller data rate.

Less secure then the infrared.

It covers the large area so it is much more open to attack the

other people.

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REMOTE SENSING TECHNIQUE:INTRODUCTION:

Remote sensing is the science (and to some extent, art) of acquiring information

about the earths surface without actually being in contact with it. This is done by

sensing and recording reflected or emitted energy and processing, analyzing and

applying that information

Applications of remote sensing data:

Conventional radar is mostly associated with aerial traffic control, earlywarning, and certain large scale meteorological data. Doppler radar is usedby local law enforcements' monitoring of speed limits and in enhancedmeteorological collection such as wind speed and direction within weathersystems. Other types of active collection includes plasmas in the ionosphere).Interferometric synthetic aperture radar is used to produce precise digitalelevation models of large scale terrain (See RADARSAT,TerraSAR-X,Magellan).

Laser and radar altimeters on satellites have provided a wide range of data.By measuring the bulges of water caused by gravity, they map features onthe seafloor to a resolution of a mile or so. By measuring the height andwave-length of ocean waves, the altimeters measure wind speeds anddirection, and surface ocean currents and directions.
http://en.wikipedia.org/wiki/Radarhttp://en.wikipedia.org/wiki/Plasma_(physics)http://en.wikipedia.org/wiki/Ionospherehttp://en.wikipedia.org/wiki/Interferometric_synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Digital_elevation_modelhttp://en.wikipedia.org/wiki/Digital_elevation_modelhttp://en.wikipedia.org/wiki/RADARSAThttp://en.wikipedia.org/wiki/TerraSAR-Xhttp://en.wikipedia.org/wiki/Magellan_probehttp://en.wikipedia.org/wiki/Altimeterhttp://en.wikipedia.org/wiki/Radarhttp://en.wikipedia.org/wiki/Plasma_(physics)http://en.wikipedia.org/wiki/Ionospherehttp://en.wikipedia.org/wiki/Interferometric_synthetic_aperture_radarhttp://en.wikipedia.org/wiki/Digital_elevation_modelhttp://en.wikipedia.org/wiki/Digital_elevation_modelhttp://en.wikipedia.org/wiki/RADARSAThttp://en.wikipedia.org/wiki/TerraSAR-Xhttp://en.wikipedia.org/wiki/Magellan_probehttp://en.wikipedia.org/wiki/Altimeter


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Light detection and ranging (LIDAR) is well known in the examples of weaponranging, laser illuminated homing of projectiles. LIDAR is used to detect andmeasure the concentration of various chemicals in the atmosphere, whileairborne LIDAR can be used to measure heights of objects and features onthe ground more accurately than with radar technology. Vegetation remotesensing is a principle application of LIDAR.

Radiometers and photometers are the most common instrument in use,collecting reflected and emitted radiation in a wide range of frequencies. Themost common are visible and infrared sensors, followed by microwave,gamma ray and rarely, ultraviolet. They may also be used to detect theemission spectra of various chemicals, providing data on chemicalconcentrations in the atmosphere.

Stereographic pairs ofaerial photographs have often been used to maketopographic maps by imagery and terrain analysts in trafficability andhighway departments for potential routes.

Simultaneous multi-spectral platforms such as Landsat have been in usesince the 70's. These thematic mappers take images in multiple wavelengthsof electro-magnetic radiation (multi-spectral) and are usually found on earth

observation satellites, including (for example) the Landsat program or theIKONOS satellite. Maps of land cover and land use from thematic mappingcan be used to prospect for minerals, detect or monitor land usage,deforestation, and examine the health of indigenous plants and crops,including entire farming regions or forests.

Within the scope of the combat against desertification, remote sensing allows to follow-up and

monitor risk areas in the long term, to determine desertification factors, to support decision-makers in defining relevant measures of environmental management, and to assess their impacts.
http://en.wikipedia.org/wiki/Light_detection_and_ranginghttp://en.wikipedia.org/wiki/Radiometerhttp://en.wikipedia.org/wiki/Photometerhttp://en.wikipedia.org/wiki/Emission_spectrahttp://en.wikipedia.org/wiki/Stereoscopyhttp://en.wikipedia.org/wiki/Aerial_photographhttp://en.wikipedia.org/wiki/Topographic_maphttp://en.wikipedia.org/wiki/Earth_observation_satellitehttp://en.wikipedia.org/wiki/Earth_observation_satellitehttp://en.wikipedia.org/wiki/Landsat_programhttp://en.wikipedia.org/wiki/IKONOShttp://en.wikipedia.org/wiki/Desertificationhttp://en.wikipedia.org/wiki/Light_detection_and_ranginghttp://en.wikipedia.org/wiki/Radiometerhttp://en.wikipedia.org/wiki/Photometerhttp://en.wikipedia.org/wiki/Emission_spectrahttp://en.wikipedia.org/wiki/Stereoscopyhttp://en.wikipedia.org/wiki/Aerial_photographhttp://en.wikipedia.org/wiki/Topographic_maphttp://en.wikipedia.org/wiki/Earth_observation_satellitehttp://en.wikipedia.org/wiki/Earth_observation_satellitehttp://en.wikipedia.org/wiki/Landsat_programhttp://en.wikipedia.org/wiki/IKONOShttp://en.wikipedia.org/wiki/Desertification

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