navigational aid on-board vessel in ships using radar

8/7/2019 Navigational Aid on-board Vessel in Ships Using Radar

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NAVIGATIONAL AIDS ON-BOARD VESSEL IN SHIPS

Document By

SANTOSH BHARADWAJ REDDY

Email: [email protected]

Engineeringpapers.blogspot.com

More Papers and Presentations available on

above site

ABSTRACT

RADAR is certainly one of the most important and promising technology for the

development of a notion. It not only has application in military but has versatile

application in various fields.

Scientists search towards a device to detect the things around them took a

massive step by the invention of RADAR (Radio Detection and Ranging) system. In the

early twentieth century several radio based systems were developed, one of the biggest

advances came as the result of Robert Watson-watt, a British scientist, which was used in

the Second World War.

We have analyzed in our project the marine RADAR and other supportingnavigational equipment in ships.

Our project mainly focuses on following aspects: navigational equipments on the

vessel, basic electromagnetic phenomena, basic antenna principles, RADAR antennas,

principle of working of a basic radar system, the display system used in RADAR, the

specifications and clutters obtained due to sea and rain.We have also pointed the merits

and demerits of RADAR system. Our concentration is mainly on the identification of

objects around the ship and making the path for ship to travel in a safe state without any

collision.

Radar is an electronic system for the detection and location of objects. The

Marine RADAR is one of the sophisticated tools for identification of objects above and
mailto:[email protected]:[email protected]


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around the ship. The system is further used in the military application, Traffic control and

air crafts and in many other fields.

However the fundamental aim of the RADAR system in the Hindustan Shipyard

Ltd is to provide this system on the ships to facilitate their navigational requirement and

to acquire the required data regarding the obstacles that are present around a particular

ship. The other equipment used in the ship for the communication purpose are GMDSS.

CONTENTS

S.NO

P.NO

I Introduction to Hindustan shipyard Ltd (HSL)

I. Introduction to HSL

II. Infrastructure of HSL

III. Stages of work at HSL

II Introduction to ship building

Construction of Ship Building

III Navigational equipments in ships

I. Navigational Lights

II. Navigational Console

III. Magnetic Compass

IV. Automatic Weather Station And Weather Warning System

V. Radar

VI. G.P.S/D.G.P.S receiver


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VII. Autopilot

VIII. Gyro Compass

IX. Doppler Speed Log

X. Echo sounderXI. Course Recorder, Electric Chart Display (ECDIS)Unit

XII. Wind Speed And Wind Direction Indicator

IV Elaboration to Radar systems

I. Early Methods of Warning

II. Simple Radar System

III.Determination of Range

IV.Determination of Azimuth

V.Determination of Elevation

VI.Speed Measurement

VII.Factors Effecting Detection And Ranging

VIII.Other Types of Radars

IX.Automatic Range Plotting Aid (ARPA)

X.Automatic Identification System (AIS)

V Antenna and Radar Display Unit

I. S-band antenna group

II. X-band antenna group

III. Radar display unit

VI Applications of Radars

VII Conclusion


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1.1 Introduction to Hindustan Shipyard Limited

Hindustan Shipyard Limited (HSL) is the premier ship building companieslocated on the east coast of country at 8317 north latitude and 1741 east

longitude. It is built on the shores of industrial city also known as City of

Destiny: Visakhapatnam. The natural harbor of which, adds to the advantage of

ship yard. The Dolphin nose at the entrance of the ship yard provides a natural

passage into the harbor.

Sir Sri Walchand Hirachand Scindia of the Scindia Stream Navigation

Company, Bombay, conceived an idea of setting up a ship building yard at

Visakhapatnam early in 1920s. With a wide area of about 55 acres (now more

than 100 acres), the site at Visakhapatnam provides ample accommodation for

eight launching berths (slipways) and associated work shops. The foundation was

laid for a vital industry on 21st June 1941. Ship construction was commenced in

1946.

The first vessel S.S.JALA USHA was launched on 14 th March 1948 by then

Honorable Prime Minister Pundit Jawaharlal Nehru. By the year 1952, SSNC

built 8 ships. However, SSNC being a private company was forced to end up in

losses. A new company under the corporate designation of Hindustan Shipyard

Limited was registered on 21st January 1952 with the government holding two-

thirds share capital.


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In 1961 the Hindustan Shipyard Limited became a full-fledged company

under a motto of: The main aim of HSL is to construct ships and also big

structures useful in both the off shore and on shore activities. To keep abreast

to the latest developments, techniques and methods in modernizing ship building,

Hindustan Shipyard had embarked upon phase-wise modernization and expansion

since 1969.

1.2 Infrastructure

The Hindustan Shipyard Limited has all together 200 departments with in eachassigned with certain work to be performed. HSL provides a lively example of the

co-operation and team-work due to which today she is the one of the few

companies having the certification of ISO:9001:2000,OHSAS:140001.

The infrastructure facilities available are:

1. Dock side working platforms for high pressure jet cleaning and semi-automatic

air less spraying.

2. Facilities for undertaking sand/grit blasting over 100Sqmt a day.

3. Hydraulic self-electing platforms.

4. Dynamic balancing facility.

5. Rich experience in repair of all types of vessels for oil, defense & maritime

sectors.

6. Efficient backup from shipyard facility including building dock, steel and

outfitting shops.

7. Well laid out independently piping, engineering & outfitting shops.

8. Single window for agency repairs in the east coast.

The present infrastructure refers a sight area of 1, 05,000 sqmt and a

launch track of an area 450mt. Today HSL is constructing a wide range of

vessels from 100 passenger vessels to huge 700 passenger ships. It is a good

competitor at the national and international market by constructing ships at


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lower rates taking care of the quality as well. It is rendering the services to the

nation in a planned manner.

The lists of vessels under construction at present at shipyard are as

Given below:

1.150 passenger ships: Two(11111,11112)

2.Tug (NMPT) One (11159)

3.30 K Bulker (GEML) One (11118)

4.53 K Bulker (GEML) Six (11136-11141)

5.Inshore Patrol Vessel (CGHQ): Five(11154-11158)

6.Oil Pollution Vessel (VPT) One (1179)

Recently the shipyard has bagged a prestigious project of repairing of the

Russian submarine on large scale. There are two subs already under repair with the

help of technical guidance of the Russian counterpart.

Customer service:

The quality policy of the Hindustan Shipyard Limited is based upon the ISO:

9001:2000 certifications

To produce consistently quality products to national and

international standards, in time, for customer satisfaction, at


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optimum cost, by improving effectiveness of Qualit

Management System.

1.3 Stages of work at Shipyard

The entire shipyard can be broadly classified into two major sections namely:

1. Ship Building Section.

2. Retrofit Section.

The ship Building Section/retrofit Section deals with the function of

construction of the ships involving a long systematic procedure involving certain

steps involved:

Step 1: initially all the requirements of the emending customer are taken intoconsideration with respect to the rules like SOLAS, RINA etc. A rough sketch is

of the vessel to be constructed is drawn by the DESIGN DEPARTMENT of

HSL.

Step 2: Then approval is obtained. The plan is drawn to a fair Draft copy for

further reference.

Step 3: The HULL SHOP deals with the supply of the metal in the required

dimensions. The first step is Hydraulic Washing of the metal sheets under high

pressure and temperature, due to which the extrinsic impurity agents are removed.

Step 4: The SHEARING DEPARTMENT cuts the metal sheets into certain

panels of predefined dimensions using a computer program.


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Step 5: The cut panel are fabricated into certain structures which are part of the

vessel at the FABRICATION DEPARTMENT.

Step 6: All the panels are set up according to the plan consider/given by the

DESIGN DEPARTMENT at the ERECTION DEPARTMENT.


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2.1 Construction of Ship Building:-

A vessel is a hollow structure formed by erection of different panels consists of

four major parts.

There are basically three to four decks in a normal 100 passenger ship each of

which contains type of machinery. The different decks on a vessel are:-

Deck A: It consists of the sewage tank, fresh water, fuel tank. It also consists of

auxiliary machinery like ship rudder section etc.

Deck B: It is the next deck that appears after the lowest level which consists of

secondary machinery like the ships luxury department etc.


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Deck C: This deck is the topmost deck that consists of wheelhouse, Main Engine

Room, Radar, Antenna group communication, GMDSS etc.

The process of ship construction was essentially the same throughout the

world. The flat plate forming the keel was laid on blocks, and a longitudinal girder

was attached along its centerline. The plates and beams that form the individual

frames were then cut and bent to shape according to mould-loft templates. The

frames extended from either side of the keel and vertical girder to the top of the

sides or the gunwales of the ship. The steel planting that covers the sides and

decks were fastened in place. Then the inner structural member of the hull were set

in place and fastened.

In recent years major changes in shipbuilding processes have been made

possible by welding instead of riveting parts together and by using cranes that can

lift, transfer, and place very heavy weights. The parts of the ship remain the same,

but they are assembled into large subsections or blocks in different workshops.

The size of the sections is determined according to the best use of shipyard

equipment. Often they are built up side down to facilitate the fastening together of

the parts. Often the machinery and piping for each subsection are fitted in placeduring workshop assembly.

The subsection are then moved to the building ways or then erection dock

and fitted together. Thus, much of the work on the ship can be done in several

locations at the same time, when the hull is completed, the dock is flooded and the

ship floated out.


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Overview of navigational equipments:-

Ever since the ancient days of great mariners, whether in East or West, areliable means of location in mid-ocean has been a matter of prime importance, in

other words, a matter linked with existence of mankind.

Initially, it started with the identification and referencing with planets, which

was impossible in adverse weather conditions, which led to the invention of

artificial intelligence, together with the advancement of science. Hence the need

for location at sea grew up to the research and development of position fixing,

starting from primitive magnetic needle to a host of NAVIGATIONAL AIDS,

from a signal light to radar, from a horn to Global Positioning System, from wired

to wireless systems and so on, performing with different operating principles,

improving upon improvements in technologies, presently caused th

study/presentation on the Development of Maritime Aids of Navigation, rather the

eyes and ears of the mariner.

Navigational equipments:

Navigation is a science of determining the position of a ship, aircraft, or

guided missile, and charting a course for guiding the safely and expeditiously from

one point to another. The practice of navigation requires not only through

knowledge of science of navigation, but also considerable experiment and

judgment.


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The science of nautical navigation is divided into four principal techniques:

(1) Dead Reckoning, which estimates the approximate

position of a craft solely from its course and speed.

(2) Piloting, this involves guiding the craft by frequently

reference to geographical landmarks and navigational aids

and by use of sounding.

(3) Celestial Navigation, which uses the observation of

celestial bodies to determine position on the surface of the

earth.

(4) Electronic Navigation, the most important and advanced

system of navigation today, using radio and inerti

electronic equipment. Aeronautical navigation is based on

similar principles.

Navigational equipments on vessel board

The navigational equipments generally used in vessel are as given below:

1. Lights

a) Navigational Lights

b) Search Lights

c) Day Lights

2. Navigational Console

3. Magnetic Compass

4. Automatic Weather Station & Weather Warning System (NAVTEX).

5. Radar6. G.P.S/D.G.P.S receiver

7. Auto pilot

8. Gyro compass

9. Doppler Speed Log

10. Echo sounder


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11. Course Recorder &Electronic Chart Display System (E.C.D.I.S).

12. Wind Speed & Wind Direction Indicator.

1.Lights (Navigational Lights, Search Lights and Day Lights):

Lights are set and maintained according to the law and regulations set bySOLAS.

Their basic purpose is to prevent collisions by alerting each vessel to the others

presence. Lights also indicated the relative heading of one vessel as seen from

another, and give clues to her size, special characteristics, and current operations.

Knowledge of navigation lights is important to every vessel for two reasons:

1. One is legally responsible for displaying lights of the proper color, intensity,

location and visibility on his vessel.

2. One has to depend on his knowledge of navigation lights for ensuring the safety

of vessel when operating at night or in periods of reduced visibility.

The fundamental duties of any vessel are:

Vessels are required to show the proper navigation lights from sunset to

sunrise in all conditions, good and bad. During these, no other lights that

could be mistaken for lights specified in the rules of the road should be

displayed, nor any lights that impair the visibility or distinctiv

navigation lights, or interface with the keeping of a proper lookout.

Vessel should be in a position to interpret the message being delivered by

the Navigation Lights of other vessels.

The rules also state that navigation lights are shown in conditions of reduced

visibility, and may be shown at other times considered necessary.

The lights generally fixed are:

Masthead light:


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225 white light showing

Ahead to 22.5 abaft the

beam on both sides

It is also known as a steaming light. The masthead light is a white light that isvisible for an arc extending across the forward 225 of the boat.

Side Lights:

For use on sail or power driven vesselsunder 20 meters (65.6') in length

Sidelights : 112.5 green light (starboard) and red light

(port) showing ahead to 22.5 abaft the beam ...

Combination Lights:

Quasarlights are intelligently planned for easierinstallation, maintenance, and efficient light output.For use on boats up to 65.6 feet (20 meters).
http://en.mimi.hu/boating/light.htmlhttp://en.mimi.hu/boating/ahead.htmlhttp://en.mimi.hu/boating/abaft.htmlhttp://en.mimi.hu/boating/beam.htmlhttp://en.mimi.hu/boating/steaming_light.htmlhttp://en.mimi.hu/boating/light.htmlhttp://en.mimi.hu/boating/forward.htmlhttp://en.mimi.hu/boating/boat.htmlhttp://en.mimi.hu/boating/light.htmlhttp://en.mimi.hu/boating/starboard.htmlhttp://en.mimi.hu/boating/light.htmlhttp://en.mimi.hu/boating/port.htmlhttp://en.mimi.hu/boating/ahead.htmlhttp://en.mimi.hu/boating/abaft.htmlhttp://en.mimi.hu/boating/beam.htmlhttp://en.mimi.hu/boating/light.htmlhttp://en.mimi.hu/boating/ahead.htmlhttp://en.mimi.hu/boating/abaft.htmlhttp://en.mimi.hu/boating/beam.htmlhttp://en.mimi.hu/boating/steaming_light.htmlhttp://en.mimi.hu/boating/light.htmlhttp://en.mimi.hu/boating/forward.htmlhttp://en.mimi.hu/boating/boat.htmlhttp://en.mimi.hu/boating/light.htmlhttp://en.mimi.hu/boating/starboard.htmlhttp://en.mimi.hu/boating/light.htmlhttp://en.mimi.hu/boating/port.htmlhttp://en.mimi.hu/boating/ahead.htmlhttp://en.mimi.hu/boating/abaft.htmlhttp://en.mimi.hu/boating/beam.html


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Towing Light:

Tow lights assist

towing operators

increase efficiency and

safety. Tow lightsinclude HID lights,

remote controlled

lights, work lights,

mini light bars, led

beacons and strobe

lights. Our tow lights

operate on 12 volt and

24 volt vehicle power.

We offer battery

powered tow lightsand remote controlled

lights with wireless

remotes.

All round lights:

An all-round marine navigation light which

generally limits the direction of light transmission to a

selected angle above and a selected angle below a

plane in which light transmission is to be generallydirected.

Flashing lights:

Flashing Light is a rhythmic light in which the total

duration of the light in each period is clearly shorter

than the total duration of the darkness and in which

the flashes of light are all of equal duration. . It is

normally used in light signals in lighthouse an
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lighted buoys.

Different lighthouses

have different

frequencies and not all

are flashing and mariners can find out which light

house they are near by the characteristic of the light

signal.

2.Navigationalconsole(BRIDGE/WHEEL HOUSE CONSOLE):

The term Navigational console refers to an external structure that carriesor holds together many navigational equipments like Pathfinder, InformationDisplay System, GMDSS system, Autopilot, Rudder Position Indicator, Rate ofTurn Equipment, COM pilot, Auto steer, Gyro Compass with repeaters, and otheraccessories.

Wheelhouse console

3. Magnetic Compass:

Compass is instrument that indicates direction, used by mariners, pilots,

hunters, campers, and other to enable them to get from one place to another.

Two fundamental types of compassare used: Magnetic Compass andGyro Compass. Compass is animportant tool in navigation when thevessel is at a voyage into the sea.Even though when at times ofemergency when all other systems failto function then at such situations the

compass is an effective tool fornavigation as it gives a basic idea ofthe direction of heading of the vessel.
http://images.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/733_console_in_wheelhouse.jpg/800px-733_console_in_wheelhouse.jpg&imgrefurl=http://commons.wikimedia.org/wiki/Image:733_console_in_wheelhouse.jpg&h=600&w=800&sz=112&hl=en&start=1&um=1&tbnid=tlTR_kpdwFjsrM:&tbnh=107&tbnw=143&prev=/images%3Fq%3Dphoto%2Bof%2Bnavigation%2Bconsole%2Bwithin%2Bthe%2Bwheel%2Bhouse%26um%3D1%26hl%3Den%26rls%3DCYBA,CYBA:2008-12,CYBA:enhttp://images.google.com/imgres?imgurl=http://www.tsb.gc.ca/en/reports/marine/1994/m94l0011/Photo_4.jpg&imgrefurl=http://www.tsb.gc.ca/en/reports/marine/1994/m94l0011/m94l0011.asp%3Fprint_view%3D1&h=300&w=446&sz=43&hl=en&start=1&um=1&tbnid=UzlMJYGpEN2PaM:&tbnh=85&tbnw=127&prev=/images%3Fq%3Dphoto%2Bof%2Bnavigation%2Bconsole%2Bwithin%2Bthe%2Bwheel%2Bhouse%2Bin%2Bships%26um%3D1%26hl%3Den%26rls%3DCYBA,CYBA:2008-12,CYBA:en


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4. Automatic Weather Station & Weather Warning System(NAVTEX

RECEIVER):

Weather Forecasting, science of determining in advance changes in thecircular of the atmosphere, and the weather these bring to particular areas. Vastregions of the world do not have a variable pattern of rain, sunshine, wind, andshowers. Over deserts there is rarely any rain, and over most tropical oceans theso-called trade winds change little day by day. This weather system should giveinformation like humidity, wind, precipitation etc.

5.RADAR:

Radar is an electronic system, used to locate objects beyond the range ofvision, and to determine their distance by projecting radio waves against them.The term radar is derived from the phrase Radio Detection and Ranging. All
http://images.google.com/imgres?imgurl=http://www.fao.org/fi/figis/equipment/data/assets/images/magneticcompass.jpg&imgrefurl=http://www.fao.org/fi/website/FIRetrieveAction.do%3Fdom%3Dequipment%26xml%3Dmagneticcompass.xml&h=328&w=324&sz=32&hl=en&start=1&um=1&tbnid=foL97gfQKhivpM:&tbnh=118&tbnw=117&prev=/images%3Fq%3Dphoto%2Bof%2Bmagnetic%2Bcompass%26um%3D1%26hl%3Den%26rls%3DCYBA,CYBA:2008-12,CYBA:en


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radar systems employ a high-frequency radio transmitter to send out a beam ofelectro magnetic radiation, ranging in wavelength frequency from a centimeters to about 1m (3ft). Objects in the path of the beam reflected thesewaves back to the transmitter. The basic concepts of radar are based on the laws of

radio-wave reflection.

15 INCHES MULTICOLOR HIGH PERFORMANCE RADAR

6.G.P.S/D.G.P.S Receiver:

The Global Positioning System (GPS) is the only fully functional

Global Navigation Satellite System (GNSS). Utilizing a constellation of at least

24 Medium Earth Orbit satellites that transmit precise microwave signals, the

system enables a GPS receiverto determine its location, speed, direction, and

time. The satellite constellation is managed by the United States Air Force 50th

Space Wing. The cost of maintaining the system is approximately US$750 million

per year including the replacement of aging satellites, and research

development.

There is a built in beacon receiver, which is used as high-accuracy differential

GPS navigator. Beacon stations all over the world are pre-installed (in countries

where differential beacons are located).

Displays of longitude/latitude, boat speed and heading, average speed,

average bearing, passed time, distance/bearing to waypoint, cross track error,

course deviation, time to go, total time/distance to destination, DOP value, present
http://en.wikipedia.org/wiki/Global_Navigation_Satellite_Systemhttp://en.wikipedia.org/wiki/Satellite_constellationhttp://en.wikipedia.org/wiki/Medium_Earth_Orbithttp://en.wikipedia.org/wiki/Satellitehttp://en.wikipedia.org/wiki/Microwavehttp://en.wikipedia.org/wiki/Receiver_(radio)http://en.wikipedia.org/wiki/Geographic_locationhttp://en.wikipedia.org/wiki/United_States_Air_Forcehttp://en.wikipedia.org/wiki/50th_Space_Winghttp://en.wikipedia.org/wiki/50th_Space_Winghttp://en.wikipedia.org/wiki/United_States_dollarhttp://en.wikipedia.org/wiki/Global_Navigation_Satellite_Systemhttp://en.wikipedia.org/wiki/Satellite_constellationhttp://en.wikipedia.org/wiki/Medium_Earth_Orbithttp://en.wikipedia.org/wiki/Satellitehttp://en.wikipedia.org/wiki/Microwavehttp://en.wikipedia.org/wiki/Receiver_(radio)http://en.wikipedia.org/wiki/Geographic_locationhttp://en.wikipedia.org/wiki/United_States_Air_Forcehttp://en.wikipedia.org/wiki/50th_Space_Winghttp://en.wikipedia.org/wiki/50th_Space_Winghttp://en.wikipedia.org/wiki/United_States_dollar


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date & time (UTC or LTC), GPS satellite status, DGPS status and Mob indication

are all selectable. Four GPS satellite signals are used to compute positions in three

dimensions and the time offset in the receiver clock. Position and time from Four

GPS satellite signals.

G.P.S RECEIVER

7.Auto Pilot:

Automatic pilot is a control device that keeps a ship steering automatically ona given course. The automatic pilot contains a set of gyroscopes that providereferences for the ships course. Sensors detect when the ship deviates from thiscourse and sends signals to the control of the radar to take appropriate action.Most ship cruise on automatic pilot, also called autopilot Auto pilot isnavigational equipment that is used to steer thevessel when it has to be updated by itself withaccuracy and precision. It is also an important toolthat gives feed to other instruments for safernavigation of the vessel.

An Auto Pilot contains:

Control Unit

Distribution box

Fluxgate Compass or Standard Sensor for Magnetic Compass

Output for Solenoid Valves

Rotary or Linear Feedback and interconnecting Cables
http://images.google.com/imgres?imgurl=http://www.aeroservice.nl/IM000820.jpg&imgrefurl=http://www.aeroservice.nl/ph-fhg.html&h=480&w=640&sz=59&hl=en&start=12&um=1&tbnid=FBRHdkzLCA0WpM:&tbnh=103&tbnw=137&prev=/images%3Fq%3Dphoto%2Bof%2Bauto%2Bpilot%26um%3D1%26hl%3Den%26rls%3DCYBA,CYBA:2008-12,CYBA:enhttp://upload.wikimedia.org/wikipedia/commons/8/8d/GPS_Satellite_NASA_art-iif.jpghttp://images.google.com/imgres?imgurl=http://san-diego.siggraph.org/sigkids/PtLoma/GPS_closeup.jpg&imgrefurl=http://san-diego.siggraph.org/sigkids/PtLoma/gps_dem.html&h=480&w=640&sz=135&hl=en&start=218&um=1&tbnid=m-vERNJ5gyMP9M:&tbnh=103&tbnw=137&prev=/images%3Fq%3Dphoto%2Bof%2Bglobal%2Bposition%2Bsystem%2Breceiver%26start%3D200%26ndsp%3D20%26um%3D1%26hl%3Den%26rls%3DCYBA,CYBA:2008-12,CYBA:en%26sa%3DNhttp://images.google.com/imgres?imgurl=http://farm2.static.flickr.com/1386/1087538390_9653f32540.jpg%3Fv%3D0&imgrefurl=http://www.flickr.com/photos/pointnshoot/1087538390/&h=333&w=500&sz=95&hl=en&start=67&um=1&tbnid=CZvgf6op0QqT1M:&tbnh=87&tbnw=130&prev=/images%3Fq%3Dphoto%2Bof%2Bglobal%2Bposition%2Bsystem%2Breceiver%26start%3D60%26ndsp%3D20%26um%3D1%26hl%3Den%26rls%3DCYBA,CYBA:2008-12,CYBA:en%26sa%3DN


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Various equipments that are fed by the Autopilot

8.Gyro Compass:

The term GYRO refers to vital function in navigation. Ordinarilycompasses rarely on earth's magnetic field of point out of the right directions.

However they are quite misleading when approaching towards the north or

South Pole. This problem is rectified by the Gyro Compass. There are electric

motors which keep the rotors spinning.

The essential part of a gyro compass consists of a spinning wheel, so mounted

that it has freedom of movement about three perpendicular axes.


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The wheel in its mounting, known as Gyrocompass,

is so controlled that it axes of spin settles parallel

with true meridian, under the influences of the

earths rotation and gravity. It then becomes known

as gyro compass.

9.Doppler Speed Log:

Doppler speed log is a device that tells u the speed details like the speed

of the vessel, maximum velocity that can be achieved, Speed of the water

current, speed of the vessel approaching etc.The navigation data heading, ship's

speed and turning rate are Indicated on the LED's and can be selected via the

control panel. A tendency indicator in the form of an LED-band shoes the during

direction of the ship continually proportional to the turning rate. The rate-of-turn

indication (ROT) is given even with out external rate gyro signal via synthetic

signal formation used the alteration of gyro compass course.

Doppler speed log

10.Echo Sounder:
http://en.wikipedia.org/wiki/Image:Kreiselkompass_Schnitt_Ansch%C3%BCtz.jpg


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Echo Sounder is a device that is useful on finding the parameters like

the depth of the ocean at the particular point etc.

Earlier used versions were purely for finding out

the inside structures of landforms etc. While

navigation one finds a great problem from aquatic

organisms like fishers and others so a new

technology named as High Definition Fish

imaging Technology (HDIF) intelligently analyzes

fish and bottom echoes, sounder display.

An amazing technology breakthrough, HDFI echo sounders deliver

exceptional clarity and detail that cannot be matched by conventional fish

finders. This technology also enables us to multi-station control with the

attachments like A-scope, Chart plotters; speed display etc.The application of

echo sounder is principally to detect icebergs.

Heave sensor:

In addition to echo-sounder have sensor is also used for compensation in

ports and harbors, offshore or as part of a hydrographic mapping programmer ,

the need to measure ocean depth with the utmost accuracy is vital. Heave sensorhas been developed to work with a wide range of modern single beam echo-

sounders. This tool proves its worth when the vessel is entering a completely

undiscovered or unknown reason. It is also very much applicable in the

environment where the echo sounder stops functioning properly or where

accuracy and precession are the key factors.

11.Course Recorder & Electronic Chart Display System:

Course Recorder refers to an integrated system that consists of pilot-star D,

Nauto-pilot and Electronic Chart Display System. For course control, gyro and

magnetic or fluxgate compass can be connected.

Through automatic adaptation the ship's speed, the control Behavior of the star D is
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continuously optimized. Course changes are carried out with selectable rate of turn.

Course monitoring (set course/ magnetic compass reference) and steering gear

monitoring are integrated into a system; all control parameters are displayed

continuously.Two sets of parameters can be stored for different sailing conditions.

The simple operation of the equipment ensures safe navigation; the course is set via

a turn knob, as well as membrane keys including dodge function.

The pilot star D can be adapted to:

Steering gears with switching

and proportional solenoids

Rudder propellers

Twin-rudder equipment

Water jet drives

V drives (option)
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Navy-sailors 2400 ECDIS (Electronic Chart Display and Information System) is a

powerful real-time navigation system that integrates Official electronic chart data

with various types of positioning and navigation Systems, including GPS, radar/

Automatic Radar Plotting Aids (ARPA) and Provides facilities for voyage datarecording, Route planning and monitoring, Search and Rescue operations and

many other vital tasks.

NAUTOPILOT 2000, designed as a adaptive digital autopilot, is intended both

for sea-going ships. The system is a further developed of the suNAUTOPILOT D/A series- installed on over 5,000 ships

Connectable to all integrated bridges systems

Compatible with all established ECDIS

Radar to pilot interface

GPRS/DGPS interface

NAUTOPILOT 2000 is an open modular system whose functions can be

extended via appropriate electronic PCB's. Integrated system is composed of

RADAR, ECDIS and the gyro compass, the customer receives a complete User-

friendly navigation system. The nautopilot is a very useful and versatile instrument

that is in operation for the purposes like Course recording, Gyro feed, Autopilot


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feed and GMDSS data. Basic functions of ECDIS are:

Route planning and monitoring.

Track storage and search and storage.

Alarming systems at critical way points.

12.WIND SPEED AND WIND DIRECTION INDICATOR:

Wind speed displayed in your choice in units: KNOTS, MPH, KMPH

and MPS. Maximum wind speed is saved on the display until reset by the operator

wind direction information is clearly displayed on the circular pattern on LEDs.

Bold front panel graphics give a quick indication of the wind angle relative to

vessel heading. Bright control allows adjustment for best viewing in any light.

Wind speed and wind direction indictor

Luminous front panel marking allow viewing in darkened pilot house. 4-20 mA

inputs, Serial NMPA and voltage outputs are standard on the marine Wind

Tracker. Alarms for both Wind Speed and Wind Direction are included.
https://ats.army.mil/images%5Cs3fbfmq.png


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EARLY METHODS OF WARNING:

The earliest armies recognized the

importance of knowing the whereabouts

of their enemies. They stationed men at

lookout points so that they would be

aware of the approach of their enemy

without revealing their own positions.

Down through the centuries, mans

principal early warning system has been

a lookout stationed at a high vantage

point. The invention of the high-powered

telescope increased the range of early

warning for a particular vantage point,

but the position selected as a lookout

point was still restricted in the range due

to the need for communication with the

main body of troops. As communication

systems progressed from the drum to the

telephone and radio, it readily can be

seen how early warning progressed

proportionally.

With the advent of airlines, visual means of detection were not dependable,

particularly on cloudy days and night. A device that could detect unseen targets

was needed. One method included the use of listening devices which detected and

amplified engine noises to an audible level, long before they could be heard by the

unaided human ear.

These devices were able to determine the direction of approach by utilizing the

binaural human or two-ear effect of the human auditory system. This method wascumbersome and would be completely useless in the age of supersonic flight.


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As aircraft increased their speed and altitude, it

became evident that new equipment must be

developed which could detect and locate fast-

moving high-flying targets and track them

automatically. This resulted in the development of

radar.

A SIMPLE RADAR SYSTEM:

The general form of radar is as shown below:

1. Power Supply:-

ANTENNA

Transmitt

er

Receiver

Power suppliesfor distributionto all units

Rotation

Received

echoes

Amplified

echoes

Display

Waveguides

Trigger

Transmitted

pulses
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In the above figure, the power supply is represented as a single block.

Functionally, this block is representative. Different supplies are needed to meet the

varying requirements of a system and must be designed accordingly. The power

supply function is performed by various types of power supplies distributed

among the circuit components of the radar set.

In the figure below, the modulator, transmitter and receiver are contained in the

same chassis. In this arrangement, the group of components is

TRANSRECIEVER. (The term transceiver is an acronym from the

TRANSmitters and reCEIVER.)

2. Modulator:-

The function of modulator is to insure that all circuits connected with

the radar system operate in a definite time relationship with each other and the

time interval between pulses is of the proper length. The modulator simultaneously

sends a synchronizing signal to trigger the transmitter and the indicator sweep.

This establishes a control for the pulse repetition rate (PRR) and provides a

reference for the timing of the travel of a transmitted pulses to a return as an echo.

3. Transmitter:-

The transmitter is basically an oscillator which generates radio-

frequency (rf) energy in the form of short powerful pulses as a result of being

turned on and off by the triggering signals from the modulator. Because of the

frequencies and outputs required, the transmitter oscilloscope is a special type

known as a MAGNETRON.

4. Transmitting and Receiving Antenna System:-

The functions of the antenna system is to take the rf energy from

the transmitter, radiate this energy in a highly directional beam, receive any echoes

or reflections of transmitted pulses from targets, and pass these echoes to the

receive any echoes or reflections of transmitted pulses from targets, pass these

echoes to the receiver. In carrying out these functions the rf pulses generated in the


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transmitted are conducted to a FEEDHORN at the focal point of a directional

reflector, from which the energy is radiated in a highly directional pattern.

The transmitted and reflected energy (returned by the same dual purpose

reflector) are conducted by a common path, an electrical conductor known as

WAVEGUIDE. A wave-guide is hollow copper tubing, usually rectangular in a

cross section, having dimensions according to the wavelength or the carrier

frequency, i.e., the frequency of oscillations within the transmitted pulse or echo.

Because of this use of a common waveguide, an electronic switch, a TRANSMIT-

RECEVIER (TR) TUBE capable of rapidly switching from transmit to receive

functions, and vice versa, must be utilized to protect the receiver from damage by

the potent energy generated by the transmitter.

To protect any of the very weak echoes from being absorbed by the transmitter,

another device known as an ANTI-TR (A-TR) TUBE is used to block the passage of

these echoes to the transmitter.

The feed horn at the upper extremity of the waveguide directs the transmitted

energy towards the reflector, which focuses this energy into a narrow beam. Any

returning echoes are focused by the reflector and directed toward the feed horn and

waveguides enrooted to the receiver.

Since the rf energy is transmitted in a narrow beam, provision must be made

for directing this beam towards a target so that its range and bearing may be

measured. Normally, this is accomplished through continuous rotation of the radar

beam at a rate of about 10-20 revolutions per minute so that it will impinge upon

any targets which might be in its path. Therefore, in this basic radar system the

upper portion of the waveguide, including the feed horn, and the reflector are

constructed so that they can be rotated in the horizontal plane by a drive motor. This

rotatable antenna and reflector assembly is called the SCANNER.

5. Scanner:-


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The function of the receiver is to amplify the increase of the very weak r-f

echoes and reproduce them as video signal to be passed to the indicator. The

receiver contains a crystal mixer and intermediate frequency amplification stages

required for producing video signals used by the indicator.

6. Indicator:-

The primary function of the indicator is to provide a visual display of the

ranges and bearings of radar targets from which echoes are received. In this basis

radar system, the type of display used is the PLAN POSITION INDICATOR (PPI),

which is essential a polar diagram, with the transmitting ships position at the center.

Images of the target echoes are received and displayed at either relative or true

bearing, and at their distances from the PPI center. With a motion of the transmitting

ship is also displayed. The secondary function of the indicator is to provide the

means of operating various controls of the radar system.

The CATHODE-RAY TUBE (CRT) is the heart of the indicator. The CRT face or

screen, which is coated with a film of phosphorescent material, is the PPI.

DETERMINATION OF RANGE:-

The successful employment of pulse-modulated radar systems depends

primarily on the ability to measure distance in terms of time. The constant velocity

of radiofrequency energy is applied in radar to determine range by measuring the

time for a pulse to travel to a target and return. The radar pulse, traveling at a


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speed of 328 yards per microsecond, will reach target 164 yards away and return

in 1 microsecond; is an important radar system measurements and is known as

radar range time.

The minimum range of radar will de determined by time it takes the

receiver to recuperate from the pulse width and the strong transmitted pulse. Peak

power developed by the radar transmitter, size and reflecting characteristics of

targets, receiver sensitivity, and the length of the listening period between pulses

will all be limiting factors as far as the maximum range of a particular radar is

concerned.

In order to employ to employ the time-range relationship, the radar system must

have a time measuring devices. In addition, since there may be more than one

target in the region under search, some means of separating and identifying pulses

must de included.

DETERMINATION OF AZIMUTH:-

The measurement of the direction of a target from the radar system is

usually given as an angular position. The angle may be measured from true north

if the installation is stationary, or with respect to the heading of the vessel or

aircraft containing the radar set. The angle of the echo signal is measured by

utilizing the directional characteristics of the radar antenna system.

The simplest form of antenna for measuring azimuth or bearing is once that

produces a single-lobe pattern. The system is mounted so that it can be rotated.

The use of two lobes instead of a single lobe greatly

increases the accuracy of the antenna array. In

general, the increase is at least five times, but it can

be much greater. In addition to the greatest accuracy

of the double lobe, there is another advantage in the

sense of direction available.

If the antenna array is off-target on the side of a lobe, the signal received

by that lobe is greater. The antenna can then be rotated until the signals become

equal; the antenna is then on-target. The two lobe patterns intersect at one point
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only, known as the crossover point, at which the two lobes for this particular

azimuth produce equal signals. At all other positions of the array, unequal signals

are produced.

DETERMINATION OF ELEVATION:-

The remaining dimension necessary to locate completely an object in space

can be expressed either as an angle of elevation, or as an altitude. If one is known

the other can be calculated from the right triangle relationship and the slant

range.

The free space pattern for an antenna is based on the arrangement of the individual

elements within the systems. If the same array is placed close to the earth,

however, the vertical free-space pattern may be changed by the effect of ground

reflections. The target will then receive energy from two directions and the

effective field is the sum of the two fields produced. The reflected wave travels

farther than the direct ray in reaching the target. The addition of the fields at the

target depends on the differences in the distances traveled expresse

wavelengths.

Any method used for determining the angle of elevation, or the altitude, must

either make use of ground reflections, or completely avoid them. The threshold-

pick up method and the signal-comparison method use the effect of ground

reflections to find altitude. The titled antenna method avoids ground reflections

and measures the angle of elevation.

SPEED MEASURMENT:-

Speed is the change in distance to an object with respect to time. Thus the

existing system for measuring distance, combined with a little memory to see

where the target last was, is enough to measure speed. At one time the memory

consisted of a user making grease-pencil marks on radar screen, and then and

calculating using slide rule.

Doppler Effect:-


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However there is another that that can be used to make more accurate speed

measurements, and do so almost instantly known as the Doppler Effect. The

Doppler is changed is change in frequency of any signal due to the finite speed at

which the signal travels compared to the motion of the objects. For instance, sound

travels at the fairly low speed of around 300m/sec, which is why you here the

Doppler effect of an ambulance siren as it passes you at 3m/sec or so. Although

this results in a small 1% change in the human ear is very at detecting this change.

In the case radar the speed of light much faster than sound and thus the

resulting shift much smaller however modern electronics are even better at

detecting this change than the human ear is for sound. Speech as slow as few

centimeters per second can be easily measured, accurately in this case much better

then the measurement of distance.

FACTORS AFFECTING DETEVTION AND MEASURMENT

OF RADAR TARGETS:-

1. Factors affecting maximum range:-

Frequency: - The higher frequency of order causes greater attenuation (loss in

power) regardless of weather. Lower radar frequencies (longer wave lengths) leads

to longer detection ranges.

Peak power: - It is the useful power of the radar. Range capabilities of the radar

increases with peak power.

Pulse Length: - The longer the pulse length, greater the range of the radar because

of the greater amount of energy transmitted.

Pulse Repetition Rate (PRR): - It determines maximum measurable range of the

radar.

Beam width: - The more concentrated beam gives the greater detection range of

the radar.


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Target characteristics: - Targets that is large can be seen on scope at greater

ranges, provided line-of-sight exists between the radar antenna and the target.

Conducting materials (EX: - ships wood hull) return much weaker echoes.

Receiver sensitivity: - The more sensitive receivers have the greater detection

range.

Antenna rotation rate: - The more slowly rotate antenna of the radar. Minimum

range of the radar is equal to half of the pulse length of the radar.

2. Factors affecting minimum range: -

Pulse length:- It determines the minimum range capability of the radar. Minimum

range of the radar is equal to half of the pulse length of the radar.

Sea return:- It returns from waves may clutter the indicator and prevent the

detection of minimum range.

Side-lobe echoes:- Targets detected by the side lobes of the antenna beam pattern

are called side lobe echoes. When operating near land of large side lobe echoes

may clutter the indicator and prevent detection of close targets.

3. Factors affecting range accuracy:-

The range accuracy of radar depends upon the exactness with the time interval

between the instants of transmitting a pulse and receiving the echo can be

measured.

Fixed error: - the starting of sweep on the indicator before RF energy leaves the

antenna causes a fixed range error. This error causes the indicated range to be

greater than their true values. A device called trigger delay trigger delay circuit is

used to eliminate the fixed error.


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Line voltage: - accuracy of range measurement depends on constancy of the line

voltage supplied to the radar equipment. If supply voltage varies from its nominal

values, range indicated on the radar may be unreliable.

Frequency drifts: - Errors in range accuracy caused by slight variations in the

frequency of the oscillator used to divide the sweep into equal range intervals.

To reduce range errors caused by frequency drift, precision oscillators fixed in

radars.

Range scale: - Higher range scale settings reduce the accuracy.

TYPES OF RADARS: -

Search Radars: -Scan a wide area with pulses of short radio waves. They usually

scan the area two to four times a minute. The radar measures the distance of the

reflector by measuring the time from emission of pulse to reception and speed of

light. The radar determines the direction because the short radio waves behave like

a screen light.

Targeting Radars: - Use same principle as search but scan smaller area for more

often usually a several times a second.

Weather radars: - Use radio waves with horizontal, dual or circular polarization.

The frequency selection of weather radar is a performance compromise between

precipitation reflectivity and attenuation due to atmospheric water vapors. Some

weather radar uses Doppler to measure wind speed.

Navigational Radars: - Use very short waves that reflect from earth and stone.

They are common on commercial ships and long distance commercial aircrafts.

General radars: - Generally use navigational radar frequencies, but modulate the

pulse can determine type of the surface of the reflector.

Mapping Radars: - Used to scan a large region for remote sensing and

geography applications.


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ARPA:-

ARPA is abbreviated Range plotting aid. This is an auto track unit which

works in conjunction with an indicator to provide a valid aid to the operator in

monitoring and solving problem encountered in navigation. The Automatic Track

Unit will extend the capabilities of the basic indicator by providing the following

features:

1. Manual and automatic Acquisition of targets.

2. Automatic target tracking, with calculated and display data upon

operators request and generation of alerting signals.

3. Automatic aid for the search of new, safe course to avoid potentially

dangerous situations.

4. 4. Possibility of constructing video maps or recalling stored maps as a

aid in navigation.

Automatic tracking of targets: -

This system can track up to 20 targets simultaneously. Targets may be

manually or automatically acquired according to the procedure described below

for acquisition, manually or automatic of targets and for tracking of them.

Automatic identification system:-

The automatic identification system (AIS) was originally developed and the

vessel traffic service (VTS) by use of VHF transponder working on digital

selective call (DSC) at VHF channel 70 and is still in use along the UK costal

areas and others. Afterwards the new. This system is synchronized with GPS time

to avoid conflict among multiple users.


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The system operates in three modes-autonomous (continuous operation in

all area), assigned (data transmission interval remotely controlled by authority in

traffic monitoring service) and polled (in response to interrogation from a ship or

authority). The VHF channels 87B and 88B are commonly used in addition there

are local AIS frequencies. The ship borne AIS transponders exchanges various

data as specified by the IMO and ITU on either frequency automatically set up by

the frequency management telecom and received by the DSC receiver by the DSC

receiver on the ship. VHF transmit power is also setup for 12.5W or 2W

automatically.

The AIS improves the safety of navigation by assigning in the efficient

navigation of the ship, protection of the environment and operation of vessel

Traffic Service by satisfying the following functional requirements:

Ship-to-ship mode for collision avoidance.

A means for littoral states to obtain information about a ship and its cargo.

VTS tool i.e. Ship-to-shore traffic management.


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S BAND & X BAND ANTENNAE GROUP:-

The S-band and the X band are the two frequencies ranges mainly used in

antennae to transmit and receive the signals. The description and the general

characteristics of these antennae are explained as follows.

S-BAND ANTENNA GROUP: -

Description: -

The antenna assembly is formed on a pedestal

& antenna. Both are designed for the maximum

resistance to the severe environmental conditions in

which they must operate. Their weight &

dimensions are limited, to reduce the effect of load

on the mask.

In S-band, only pedestal 03R-028 is

available. This pedestal is equipped with

asynchronous 3-phase motor to be used with the

following supply voltages.

3x225/440v 60 Hz, 3x220/380v.50 Hz. With this

pedestal, the 12 antenna 02R-039 for S-band is

utilized.

In addition to the motor for antenna rotation and the rotating joint

connecting the microwave path of the pedestal to that of the antenna, the pedestal

also contains a circuit for formation of the heading mark, consisting of a slotted

disk & a proximity switch which, when the antenna passes through the shipsheading, sends a pulse to the indicator unit for formation of the Heading Line

(H>L) & its representation on the P.P.I.


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X Band Antenna Group L: -

Description:

The antenna assembly consists of a pedestal

and an antenna, designed for maximum resistance to

the severe environmental conditions in which it must

operate and having limited weight & dimensions to

reduce the effect of load on the mask.

The pedestals available in X-band are the following:

03R-034 for 6, 9 & 12 X-band antennas, equipped with 3- phase synchronous

motor for the following power supply voltages: 3 X 225/440V 60 Hz & 3 X

220/380V -50 Hz.

03R-034 for 6, 9 & 12 x-band antennas, equipped with 110v dc or 220V dc

motor for a 1 phase power supply

The antennae available are the following:

02R 006A1 6x p (6).

02R 007C1 9x - -P (9).

02R 047 12X p (12).

The pedestal, in addition to the motor for the antenna rotation & the rotating joint

connecting the microwave path of the pedestal with that of the antenna, also

contains the circuit for the formation of the heading line, consisting of a slotted

disc 7 a proximity switch which, in coincidence with the passage of the antenna

through the ships heading sends a pulse to the Indicator unit for formation of the

Heading Line (H.L) and its representation of the P.P.I.
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RADAR DISPLAY UNIT:

The purpose of display is to visually present in a

form suitable for operator interpretation and action

the information contained in the radar echo signal.

When a display is connected directly to the videos

output of the receiver, the information displayed is

called raw video. This is the traditional type of radar

presentation. When the receiver video output is first

processed by an automatic detector or automatic

detection and tracking processor (ADT), the output

displayed is sometimes called synthetic video.

The cathode ray tube (CRT) has been almost universally used as the radar display.
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APPLICATIONS OF RADARS

Radar has been employed on the ground, in the air, on the sea and in space.

Ground based radar has applied chiefly to the detection, location, and tracking of

aircraft or space targets. Shipboard radar is used as for observing aircrafts. Airborne

radar may be used to detect aircraft, ships or land vehicles, or it may be used for

mapping of land, storm avoidance, terrain avoidance, and navigation. In space, radar

has assisted in the guidance of spacecraft and for the remote sensing of land and sea.

The major user of radar, and contributor of the cost of almost of its

developments, has been the military; although there have been incre

important civil applications, chiefly for marine and air navigation. The major areas

of radar applications, in no particular order of importance, are briefly describedbelow.

1. Air Traffic Control (ATC): -

Radars are employed through out the world for the purpose of safety

controlling air traffic enroot and in the vicinity of airports. Aircrafts and ground

vehicular traffic at large airports are monitored by means of high resolution radar.

Radar has been used with GCA (ground control approach) systems to guide aircraft

to a safe landing in a bad weather. In addition, the microwave landing system and

the widely used ATC radar beacon system are based in large part of radar

technology.

2. Aircraft Navigation: -

The weather avoidance radar used on aircraft to outline regi

precipitation to the pilot is a classical form of radar. Radar is also used for terrain

avoidance and terrain following. Although they may not always be thought of as

radars, the radio altimeter and the Doppler navigator are also radars. Sometimes

ground mapping radars of moderately high resolutions are used for ai

navigation purposes.


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3. Ship Safety:-

Radar is used for enhancing the safety of ship travel by warning of potential

collision with other ships, and for detecting navigation buoys, especially in poor

visibility. In terms of numbers, this is one of the larger applications of radar, but in

terms of physical size and cost it is one of the smallest. It has also proven to be one

of the most reliable radar systems. Automatic detection and tracking equipments are

commercially available for use of such radars for the purpose of collision avoidance.

Shore based radar of moderately high resolution is also used for the surveillance of

harbors as an aid of navigation.

5. Space: -

Space vehicles are used for rendezvous and docking, for landing on the

moon. Some of the largest ground based radars are for detection and tracking of

satellites. Satellites borne have also been used for remote sensing.

6. Remote Sensing: -

All radars are remote sensors; however, as this term is used it implies the

sensing of geophysical objects, or the environment. For sometime, radar has been

used as a remote sensor of the weather. It was also used in the past to probe the

moon and the planets (radar astronomy). The ionosphere sounder, an important

adjunct for HF (short wave) communications, is radar. Remote sensing of radar is

also concerned with Earth resources, which includes the measurement and mapping

of sea conditions, ice cover, water resources, agriculture, forestry conditions,geological conditions, and the environmental pollution. The platforms for such

radars include satellites as well as aircrafts.


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7. Law Enforcement: -

In addition to the wide use of radar to measure the speed of automobile traffic

by the high way police, radar has also been employed as a means for the detection of

intruders.

8. Military: -

Many of the civilian applications of radar are also employed by the military.

The traditional role of radars for military applications has been u

surveillance, navigation, and for the control and guidance of weapons. It represents,

by far, the largest use of radar.


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CONCLUSION

RADAR (Radio Detection and Ranging) is a technology invented in the

1930s to detect distant objects, mainly aircraft and ships. Since detection is done by

receiving radio waves reflected from the target, radar works the same by day nightand in all weather, which makes it a revolutionary long range observation tool, both

military, and also civilian.

Due to different designs parameters, no single radar set has been

produced that can perform all of the radar functions required by combatant ships.

As a result, the modern warship has several radar sets, each performing a specific

function.

The latest technologies developed in navigation to overcome

difficulties in present Radar System are Automatic Range Plotting Aid and

Automatic Identification System etc. which are going to influence the navigation

system by improving their safety.

ARPA is an auto track unit which works in conjunction with an indicator

to provide a valid aid to the operator in monitoring and solving

encountered in navigation.

The Automatic Identification System (AIS) was originally developed to

and the vessel traffic services (VTS) by use of VHF transponder working on digital

selective call (DSC) at VHF channel 70 and is still in use along the UK costal areas

and others.

Navigation is a science of detecting the position of a ship, aircraft orguided missile, and charting a course for guiding the craft safely and expeditiously

from one point to another. The practice of navigation requires not only through

knowledge of the science of navigation, but also considerable experiment and

judgment. It is divided into a few principle techniques.


50/50

Dead rocking estimates the approximate position of a craft solely from its

course and speed. Piloting involves guiding the craft by frequent reference to

geographical landmark and navigational aids and by use of sounding. Celestial

Navigation uses the observation of celestial bodies to determine position on the

surface of the Earth.

Electronic Navigation, the most important and advance system of navigation today,

uses radio and inertial electronic equipment. Aeronautical navigation is based on

similar principles.

Document BySANTOSH BHARADWAJ REDDYEmail: [email protected]

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navigational aid on-board vessel in ships using radar

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