PROJECT REPORT
ON
AN
INTRODUCTION
TO RADAR
FACULTY GUIDE: SUBMITTED BY:
Mr. SANJEEV SAXENA PRATEEK JAIN Mr. BHUPENDRA SINGH A2305108310
B.TECH (E&CE) BATCH (2008-2012) VIITH SEMESTER
ACKNOWLEDGEMENTS
I wish to express my sincere thanks to the management of Bharat Electronics Limited (BEL), Bharat Nagar, Ghaziabad including the Head of the Human Resource Development Department Mr. Neeraj Kumar (DGM, H.R.D.) for providing me an opportunity to receive training in this esteemed company.
I am deeply indebted to Mr. TM.T. MURLI, Sr. Deputy General Manager, Radar Division (TESTING) for sparing his most precious time in providing guidance to me in training. Without his wise counsel, inestimable encouragement, it would have been difficult for me to have knowledge of the functioning of various types of electronics equipment particularly radars. Gratitude is also due to him for his constant guidance and direction in writing this piece of work.
Special thanks to Mr. SANJAY KUMAR, and Mr. MANOJ JONWAL, Deputy Engineer for their valuable guidance, help and co-operation.
It is a great pleasure to express my heart full thanks to staff of BEL who helped me directly or indirectly through out the successful completion of my training. There is no substitute to ‘Team Work’; this is one of the lessons I learnt during my training in
ABSTRACT
Aim of this Training document is to introduce and analyze the configuration and the characteristics of the SRE radar system for training purposes. This project report focuses on the various departments to give us a brief insight of the company’s functioning and knowledge of the various departments. A brief idea of the jobs done at the particular departments was given. The working protocols of various departments are mentioned in this project report. Test equipment and automation, P.C.B fabrication, quality control works-radar, work assembly-communication, magnetic, microwave lab are different departments which has been discussed in this project report. Project report also focuses on radar system, its principle, radar working, and its applications.
Radar is basically a machine which means RADIO DETECTION AND RANGING. It is used to detect or indentify an object and it also finds range and angel of an object. Radar is an electromagnetic system for the detection and location of reflecting objects such as aircrafts, ships, spacecraft, vehicles, peoples and the natural environment. It operates by radiating energy into space and detecting the reflected echo signal from an object, or target. The reflected energy to the radar not only indicates the presence of a target, but by comparing the received echo signal with the signal that was transmitted, its location can be determined along with other target related information. On the basis of these characteristics radar is divided into two categories: 2-D radar and 3-D radar. Radar is also categories on the basis of way communication i.e. PRIMARY RADAR and SECONDARY RADAR.
Primary section of SURVEILLANCE RADAR EQUIPMENT has been discussed in report. It is an AIR TRAFFIC CONTROLLING RADAR, which is based on the principle of echo effect.Surveillance radar equipment basically divided into three parts: TRANSMITTER, RECEIVER AND ANTENNA. Transmitter is used to amplify the signal and the output is send to antenna, which converts the signal into electromagnetic waves and spread into the region or targeted location. Receiver
section receives the reflected signal (reflected back by the object). Transmitter block contain divider, which divide the signal into eight parts, high power amplifiers and combiner.
Table of contents
I. Acknowledgements……….……2 II. Abstract………...3 III. Certificate………....6 IV. Declaration………..7 V. Rotation program………8 VI. BEL • Introduction………..9• Corporate motto, mission and objectives……….12
• Manufacturing units……….13
• Customer profile and product range……….16
• Financial performance………...19
• BEL Ghaziabad unit……….20
VII. Test equipment and automation………..27
VIII. Magnetics………29
IX. Microwave laboratory……….31
X. P.C.B Fabrication………32
XI. Work assembly………....35
XII. RADAR • Introduction………..38
• Radar development...………38
• Basic principle………...39
• Types of radar………..40
• Basic radar system………42
• Working of radar………..44
• Radar equation……….46
• Applications of radar………..…….47
XIII. Surveillance radar equipment………..49
XIV. Result and discussion..………....58
XV. Conclusion………..59
XVI. Appendix…...……….60
CERTIFICATE
TO WHOM SO EVER IT MAY CONCERN
This is to certify that PRATEEK JAIN student of B.tech
(Electronics and Communication Engineering ) from AMITY
UNIVERSITY (NOIDA) has undergone an industrial training
on project titled ‘AN INTRODUCTION TO RADAR’ at
BHARAT
ELECTRONICS LIMITED
, GHAZIABAD w.e.f
9
thMay 2011 to 19
thJune 2011 under the guidance of Mr.
Sanjay Kumar and Mr. Manoj Jonwal.
They worked diligently and made valuable contribution during
this period. All their works are genuine and original.
Mr. T M MURALI
(Sr. DEPUTY GENERAL MANAGER)
(PROJECT GUIDE)
DECLARATION
I hereby declare that the project work entitled “UPT RECORDFORM” is an authentic work carried by me at Bharat Electronics Limited, Ghaziabad , under worthy and esteemed guidance Mr.TM MURALI (Sr. DEPUTYGENERAL MANAGER) at Bharat Electronics Limited , Ghaziabad.
This work has not been submitted to any other institution or university for award of any degree
ROTATION PROGRAM
Under this students are introduced to the company by putting them under a rotation program to various departments. The several departments where I had gone under my rotational program are:
Test Equipment and Automation P.C.B. Fabrication
Quality Control Works-Radar Work Assembly- Communication Magnetic
Microwave lab
Rotation period was to give us a brief insight of the company’s functioning and knowledge of the various departments. A brief idea of the jobs done at the particular departments was given. The cooperative staff at the various departments made the learning process very interesting , which allowed me to know about the company in a very short time.
BHARAT ELECTRONICS
LIMITED
INTRODUCTION
India, as a country, has been very lucky with regard to the introduction of telecom products. The first telegraph link was commissioned between Calcutta and Diamond Harbor in the year 1852, which was invented in 1876. First wireless communication equipment were introduced in Indian Army in the year 1909 with the discovery of Radio waves in 1887 by Hertz and demonstration of first wireless link in the year 1905 by Marconi and Vacuum Tube in 1906. Setting up of radio station for broadcast and other telecom facilities almost immediately after their commercial introduction abroad followed this. After independence of India in 1947 and adoption of its constitution in 1950, the government was seized with the plans to lay the foundations of a strong, self-sufficient modern India. On the industrial front, Industrial Policy Resolution (IPR) was announced in the year 1952. It was recognized that in certain core sectors infrastructure facilities require huge investments, which cannot be met by private sector and as such the idea of Public Sector Enterprises (PSR) was mooted. With telecom and electronics recognized among the core sectors, Indian Telephone Industry, now renamed as ITI Limited, was formed in 1953 to undertake local manufacture of telephone equipment, which were of electro-mechanical nature at that stage. Hindustan Cable Limited was also started to take care of telecom cables.
Bharat Electronics Limited (BEL) was established in 1954 as a public Sector Enterprise under the administrative control of Ministry of Defence as the
fountainhead to manufacture and supply electronics components and equipment. BEL, with a noteworthy history of pioneering achievements, has met the requirement of state-of-art professional electronic equipment for Defence, broadcasting, civil Defence and telecommunications as well as the component requirement of entertainment and medical X-ray industry. Over the years, BEL has grown to a multi-product, multi-unit, and technology driven company with track record of a profit earning PSU.
The company has a unique position in India of having dealt with all the generations of electronic component and equipment. Having started with a HF receiver in collaboration with T-CSF of France, the company’s equipment designs have had a long voyage through the hybrid, solid-state discrete component to the state of art integrated circuit technology. In the component arena also, the company established its own electron value manufacturing facility. It moved on to semiconductors with the manufacture of germanium and silicon devices and then to the manufacture of Integrated circuits. To keep in pace with the component and technology, its manufacturing and products assurance facilities have also undergone sea change. The design groups have CADD facility, the manufacturing has CNC machines and a Mass Manufacture Facility. QC checks are preformed with multi-dimensional profile measurement machines, Automatic testing machines, environmental labs to check extreme weather and other operational conditions. All these facilities have been established to meet the stringent requirements of MIL grade systems.
Today BEL’s infrastructure is spread over nine locations with 29 production divisions having ISO-9001/9002 accreditation. Product mix of the company are spread over the entire Electro-magnetic (EM) sp 3ectrum ranging from tiny audio frequency semiconductor to huge radar systems and X-ray tubes on the upper edge of the spectrum. Its manufacturing units have special focus towards the products ranges like Defence Communication, Rader’s, Optical & Opto-electronics, Telecommunication, sound and Vision Broadcasting, Electronic Components, etc.
Besides manufacturing and supply of a wide variety of products, BEL offers a variety of services like Telecom and Rader Systems Consultancy, Contract Manufacturing, Calibration of Test & Measuring Instruments, etc. At the moment, the
company is installing MSSR radar at important airports under the modernization of airports plan of National Airport Authority (NAA).
BEL has nurtured and built a strong in-house R&D base by absorbing technologies from more than 50 leading companies worldwide and DRDO Labs for a wide range of products. A team of more than 800 engineers is working in R&D. Each unit has its own R&D Division to bring out new products to the production lines. Central Research Laboratory (CRL) at Bangalore and Ghaziabad works as independent agency to undertake contemporary design work on state-of-art and futuristic technologies. About 70% of BEL’s products are of in-house design.
BEL was among the first Indian companies to manufacture computer parts and peripherals under arrangement with International Computers India Limited (ICIL) in 1970s. BEL assembled a limited number of 1901 systems under the arrangement with ICIL. However, following Government’s decision to restrict the computer manufacture to ECIL, BEL could not progress in its computer manufacturing plans. As many of its equipment were microprocessor based, the company,
Continued to develop computers based application, both hardware and software. Most of its software requirements are in real time. EMCCA, software intensive navel ships control and command system is probably one of the first projects of its nature in India and Asia.
BEL has won a number of national and international awards for Import Substitution, Productivity, Quality, Safety, Standardization etc. BEL was ranked No. 1 in the field of Electronics and 46th overall among the top 1000 private and public sector undertakings in India by the Business Standard in its special supplement “The BS 1000 (1997-98)”. BEL was listed 3rd among the Mini Ratanas (Category II) by the Government of India, 49th among Asia’s top 100 worldwide Defence Companies by the Defence News, USA.
CORPORATE MOTTO , MISSION
AND OBJECTIVES:
The passionate pursuit of excellence at BEL is reflected in a reputation with its customers that can be described in its motto, mission and objectives:
CORPORATE MOTTO
“ Quality, Technology and Innovation .”
CORPORATE MISSION
To be the market leader in Defence Electronics and in other chosen fields and products.
CORPORATE OBJECTIVES
To become a customer-driven company supplying quality products at competitive prices at the expected time and providing excellent customer support.
To generate internal resources for financing the investments required for modernization, expansion and growth for ensuring a fair return to the investor. In order to meet the nation’s strategic needs, to strive for self-reliance by
indigenization of materials and components.
To retain the technological leadership of the company in Defence and other chosen fields of electronics through in-house research and development as well as through Collaboration/Co-operation with Defence/National Research Laboratories, International Companies, Universities and Academic Institutions. To progressively increase overseas sales of its products and services.
to realize their full potential through continuous learning on the job and through other HRD initiatives.
MANUFACTURING UNITS
BANGALORE (KANARATAKA)
BEL started its production activities in Bangalore on 1954 with 400W high frequency (HF) transmitter and communication receiver for the Army. Since then, the Bangalore Complex has grown to specialize in communication and Radar/Sonar Systems for the Army, Navy and Air-force.
BEL’s in-house R&D and successful tie-ups with foreign Defence companies and Indian Defence Laboratories has seen the development and production of over 300 products in Bangalore alone. The Unit has now diversified into manufacturing of electronic products for the civilian customers such as DoT, VSNL, AIR and Doordarshan, Meteorological Dept., ISRO, Police, Civil Aviation and Railways. As an aid to Electorate, the unit has developed Electronic Voting Machines that are produced at its Mass Manufacturing Facility (MMF).
GHAZIABAD (UTTER PRADESH)
The second largest Unit at Ghaziabad was set up in 1974 to manufacture special types of radar for the Air Defence Ground Environment Systems (Plan ADGES). The Unit provides Communication Systems to the Defence Forces and Microwave Communication Links to the various departments of the State and Central Govt. and other users. The Unit’s product range included Static and Mobile Radar, Tropo scatter equipment, professional grade Antennae and Microwave components.
PUNE (MAHARASHTRA)
This Unit was started in 1979 to manufacture Image Converter Tubes. Subsequently, Magnesium Manganese-dioxide Batteries, Lithium Sulphur Batteries and X-ray Tubes/Cables were added to the product range. At the present the Laser Range Finders for the Defence services.
MACHILIPATNAM (ANDHRA PRADESH)
The Andhra Scientific Co. at Machilipatnam, manufacturing Optics/Opto-electronic equipment was integrated with BEL in 1983. the product line includes passive Night Vision Equipment, Binoculars and Goggles, Periscopes, Gun Sights, Surgical Microscope and Optical Sights and Mussel Reference Systems for tank fire control systems. The Unit has successfully diversified to making the Surgical Microscope with zoom facilities.
PANCHKULA (HARYANA)
To cater the growing needs of Defence Communications, this Unit was established in 1985. Professional grade Radio-communication Equipment in VHF and UHF ranges entirely developed by BEL and required by the Defence services are being met from this Unit.
CHENNAI (TAMIL NADU)
In 1985, BEL established another Unit at Chennai to facilitate manufacture of Gun Control Equipment required for the integration and installation and the Vijay anta tanks. The Unit is now manufacturing Stabilizer Systems for T-72 tanks, Infantry Combat Vehicles BMP-II, Commander’s Panoramic Sights & Tank Laser Sights are among others.
KOTDWARA (UTTER PRADESH)
In 1986, BEL STARTED A unit at Kotdwara to manufacture Telecommunication Equipment for both Defence and civilian customers. Focus is being given on the requirement of the Switching Equipment.
TALOJA (MAHARASHTRA)
For the manufacture of B/W TV Glass bulbs, this plant was established in collaboration with coming, France in 1986. The Unit is now fully mobilized to manufacture 20’’ glass bulbs indigenously.
HYDERABAD (ANDHRA PRADESH)
To coordinate with the major Defence R&D Laboratories located in Hyderabad, DLRL, DRDL and DMRL, BEL established a Unit at Hyderabad in 1986. Force Multiplier Systems are manufactured here for the Defence services.
JOINT VENTURES
BE-Delft Electronics Limited
BE-Delft Electronics Limited, Pune, the first joint venture of the company with Delft Instruments, Holland and UTI was established in the year 1990 for conducting research, development and manufacture of Image Intensifier Tubes and associated high voltage power supplies for use in military, security and commercial systems. Its products include night vision goggles and binoculars, night vision weapon sights and low light level input applications.
GE BE Private Limited
GE BE Private Limited, Bangalore, a JV with General Electric Medical Systems, USA has been established in 1997-98 for manufacture of High End Routing Anode Medical Diagnostic X-ray tube called CT MAX, which is used in CT Scanners. The joint venture unit will also establish a reloading facility for X-ray tubes and will also market the conventional X-ray tubes made at Pune Unit of BEL. South East Asia market are addressed by this joint venture.
BEL- Multitone Private Limited
A joint venture between Bharat Electronics and Multitone Electronics Plc, UK has also been established in Bangalore in 1997-98 to manufacture state-of-art Mobile Communication for the workplace. Multitone invented paging in 1956 when it developed the world’s first system to serve the “life or death” environment of St. Thomas Hospital, London. With the strength of Bharat Electronics in the Radio Communications fields and the technology of Multitone, in the field of Radio Paging, the joint venture company is in a position to offer tailor made solution to the Mobile Communication needs at workplace in various market segments.
CUSTOMER PROFILE & BEL
PRODUCT RANGE
Equipments:
DEFENCEARMY Tactical and Strategic Communication Equipment and Systems, Secrecy Equipment, Digital Switches, Battlefield Surveillance Radar, Air Defence and Fire Control Radar, Opto-Electronic Instruments, Tank Fire Control Systems, Stabilizer Systems, Stimulators and Trainers.
NAVY Navigational, Surveillance, Fire Control Radar, IFF, SONAR Systems, Torpedo Decoys, Display Systems, EW Systems, Simulators, Communication Equipment and Systems.
AIR FORCE Surveillance and Tracking Raiders, Communication Equipment and Systems, IFF and EW Systems.
NON-DEFENCE
PARA-MILITARY Communication Equipment and Systems.
SPACE DEPARTMENT Precision Tracking Radar, Ground Electronics, Flight and On-board Sub-Systems.
ALL INDIA RADIO MW, SW &FM Transmitters.
DOORDARSHAN (TV NETWORK)
Low, Medium and High Power Transmitters, Studio Equipment, OB Vans, Cameras, Antennae, Mobile and Transportable Satellite Uplinks.
NCERT TV Studios on turnkey Basis for Educational Programs.
DEPARTMENT OF
TELECOMMUNICATION
Transmission Equipment (Microwave and UHF) and PCM Multiplex, Rural and Main Automatic Exchanges, Flyaway Satellite Terminals, Solar Panels for Rural Exchanges.
VIDESH SANCHAR NIGAMAND OTHER CORPORATE BODIES
MCPC VSAT, SCPC VSAT, Flyaway Earth Stations. Hub Stations, Up/Down Converters, LNA Modems.
CIVIL AVIATION Airport Surveillance Radar, Secondary Surveillance Radar.
METEOROLOGICAL DEPARTMENT
Cyclone Warning and Multipurpose Meteorological Radar.
POWER SECTOR Satellite Communication Equipment.
OIL INDUSTRY Communication Systems, Radar.
FOREST DEPARTMENTS, IRRIGATION &
ELECTRICITY BOARDS
Communication Systems.
MEDICAL & HEALTH CARE
Clinical and Surgical Microscope with Zoom, Linear Accelerators.
RAILWAYS Communication Equipment for Metros, Microwave Radio Relays and Digital Microwave Radio Relays.
Components:
DEFENCE Transmitting Tubes, Microwave Tubes, Lasers,
Circuits.
NON-DEFENCE All India Radio, Doordarshan (TV Network),
Telecommunications and Civil Industries
Transmitting Tubes, Microwave Tubes, and Vacuum Tubes.
Entertainment Industry B/W TV Tubes, Silicon Transistors, Integrated Circuits, Bipolar and CMOS, Piezo-Electric Crystals, Ceramic Capacitors and SAW Filters.
Telephone Industry Integrated Circuits, Crystals.
Switching Industry Vacuum Interrupters.
Instrumentation Industry Liquid Crystal Displays. Medical & Health Care X-ray Tubes.
System/Networks:
Identity Card Systems Software, Office Automation Software, LCD On-line Public Information Display Systems and Communication Networks / VSAT Networks.
FINANCIAL PERFORMANCE
BEL has a unique history of profit making Public Sector Enterprise right from its inception. There have been events of decrease in turnover and profit after Tax due to
reasons beyond reasonable control of the company. But the company’s strength lies in its capability to combat the threats, for example US Embargo on exports to BEL.
BEL hopes to generate 25 per cent increase in turnover with a 15 per cent rise in net profit in the current fiscal year over the previous. Corrective measures against western sanctions have been undertaken, which are likely to translate into higher turnover and profitability. The company is putting all efforts to minimize the effect of the restrictions by early establishments of alternative arrangements. The Defence Research Laboratories and Academic Institutions are also being persuaded with for indigenisation of certain special category of devices and components. The company is also opening an office in Singapore to procure components from Asian markets. Thus in the long run the restrictions will prove as blessings resulting in self-dependence and better profit margins.
Also several R&D projects with long gestation periods will go into commercial production during the current fiscal.
BEL GHAZIABAD UNIT
In the mid 60’s, while reviewing the Defence requirement of the country, the government focused its attention to strengthen the Air Defence system, in particular the ground electronics system support, for the air Defence network. This led to the formulation of a very major plan for an integrated Air Defence Ground Environment System known as the plan ADGES with Prime Minister as the presiding officer of the apex review committee .At about the same time, Public attention was focused on the report of the Bhabha committee on the development and production of electronic equipment. The ministry of Defence immediately realized the need to establish production capacity for meeting the electronic equipment requirements for its plan ADGES.
BEL was then inserted with the task of meeting the development and production requirement for the plan ADGES and in view of the importance of the project it was decided to create additional capacity at a second unit of the company.
In December 1970 the Govt. sanctioned an additional unit for BEL. In 1971, the industrial license for manufacture of radar and microwave equipment was obtained, 1972 saw the commencement of construction activities and production was launched in 1974.
Over the years, the unit has successfully manufactured a wide variety of equipment needed for Defence and civil use. It has also installed and commissioned a large number of systems on turnkey basis. The unit enjoys a unique status as manufacture of IFF systems needed to match a variety of primary raiders. More than 30 versions of IFF’s have already been supplied traveling the path from vacuum technology to solid-state to latest Microwave Component based system.
PRODUCT RANGES
The product ranges today of the company are: 3-Dimensional High Power Static and Mobile Radar for the Air Force. Low Flying Detection Radar for both the Army and the Air force. Tactical Control Radar System for the Army.
Battlefield Surveillance Rader for the Army.
IFF Mk-X Radar systems for the Defence and export. ASR/MSSR systems for Civil Aviation.
Radar & allied systems Data Processing Systems.
COMMUNICATIONS
Digital Static Tropo scatter Communication Systems for the Air Force.
Digital Mobile Tropo scatter communication System for the Air Force and Army.
VHF, UHF & Microwave Communication Equipment. Bulk Encryption Equipment.
Turnkey communication Systems Projects for Defence & civil users. Static and Mobile Satellite Communication Systems for Defence. Telemetry /Tele-control Systems.
ANTENNA
Antennae for Radar, Terrestrial & Satellite Communication Systems. Antennae for TV Satellite Receive and Broadcast applications. Antennae for Line-of-sight Microwave Communication Systems.
MICROWAVE COMPONENT
Active Microwave components like LNAs, Synthesizer, Receivers etc. Passive Microwave components like Double Balanced Mixers,etc.
Most of these products and systems are the result of a harmonious combination of technology absorbed under ToT from abroad, Defence R&D Laboratories and BEL’s own design and development efforts.
THE ORGANIZATION
Additional / Deputy General Manager heading various divisions as follows:
DESIGN & ENGINEERING DIVISIONS
Development and Engineering-R Development and Engineering-C
Development and Engineering-Antenna.
EQUIPMENT MANUFACTURING DIVISIONS
Radar Communication Antenna Systems Microwave Components
SUPPORT DIVISIONS
Material management Marketing & Customer Co-ordination Quality Assurance & Torque
Central Services PCB & Magnetics Information Systems Finance & Accounts
Personnel & Administration Management Services.
DESIGN & ENGINEERING
The pace of development and technological obsolescence in their field of electronics necessitates a strong Research and Development base. This is more important on the area of Defence Electronics. BEL Ghaziabad has since its inception
laid a heavy emphasis on indigenous research and development. About 70% its of manufacture today relate to items developed in-house. For the development and production of the Mobile Torpo scatter System and the equipment, BEL was awarded the Gold Shield for Import Substitution.
Design facilities are also constantly being modernized and substantial computer-aided design facilities are being introduced including installation of mini- and microcomputers and dedicated design application. About 170 graduate and post-graduate engineers are working on research and indication of the importance R&D has in BEL’s growth.
Three Design and Engineering group are product based viz. Communication, Radar and Antenna. These divisions are further divided into different departments to look after products of a particular nature. each of them has a drawing office attached to them, which are equipped with latest drafting and engineering software. The PCB layout and PCB master making is done at CADD Center. A central Records & Printing section takes care of the preserving the engineering documents and distribution thereof. Most of the engineering documents are available online.
EQUIPMENT MANUFACTURING DIVISIONS
As a supplier of equipment to the Defence services and professional users, strict adherence to specifications and tolerances, has to be in-built into the design and manufacturing process. For this BEL Ghaziabad has well defined standards and processes for as well as manufacturing and testing activities. Activities are divided into various departments like Production Control, Works Assembly, and QC WORKS. The manufacture and control of production is through a central systems, BELMAC, BEL’s own homegrown ERP system.
Apart from conventional machines, BEL Ghaziabad has been equipped with several repeat occurrences and increased throughput. A separate NC programming cell has been set up to develop the programs for execution on the CNC machines.
Frequencies greater than 1 GHz are termed as Microwaves. Microwaves Integrated Circuits (MIC) used extensively in the production of subsystems for Radar and Communication equipment constitutes a very vital part of the technology for these systems and is generally imported. Owing to the crucial and building block nature of the technology involved, BEL is currently setting up a modern MIC manufacturing facility at a planned expenditure of Rs. 2 crore. When in full operation, this facility will be the main center for the MIC requirements of all the units of the company.
The manufacturing facilities of hybrid microwave components available at BEL, Ghaziabad includes facility for preparation of substrates, assembly of miniaturized component viz. directional couplers, low noise amplifiers, phase shiftier, synthesizers etc. involves scalar as well as vector measurements. For this state of the network analysis are used.
MATERIAL MANAGEMENT
Material Management division is responsible for procurement, storage handling, issue of purchased parts as well as raw materials required to manufacture various equipment and spares. It also takes care of disposal of unused or waste material.
The division is divided into purchase, Component store, Raw material store, Chemical store, Custom Clearance Cell, Inventory management & disposal.
MARKETING AND CUSTOMER CO-ORDINATION
This division is responsible foe acquisition and execution of customer orders and customer services. Marketing department looks after order acquisition. Commercial department looks after order execution. Shipping takes care of packing and dispatch of material to customer.
QUALITY ASSURANCE & TORQUE
In the area of professional Defence electronics, the importance of Quality and Reliability is of utmost importance. BEL has therefore established stringent processes and modern facilities and systems to ensure product quality- from the raw material to the finished product. IGQA, Environmental Labs, Test Equipment Support and QA
departments are grouped under this division.
All material for consumption in the factory passes through stringent inward goods screening in IGQA department before being accepted for use.
Subsequent to manufacture and inspection, the end product is again put through a rigorous cycle of performance and environmental checks in Environmental Labs.
The testing, calibration and repair facility of test Instruments used in the
factory is under the control of Test Equipment Support. All the instruments come to this department for periodic calibration.
Quality Assurance department facilitates ISO 9000 certification of various divisions. All production divisions of BEL Ghaziabad are ISO9000 certified. The microwave division is ISO9001 certified whereas the remaining three division viz. Radar, Communication and Antennae are also ISO9002 certified.
CENTRAL SERVICES
Central services Division looks after plant and maintenance of the estate including electrical distribution, captive power generation, telephones, transport etc.
PCB FABRICATION & MAGNETICS
PCB Fabrication, Coil and Magnetics, Technical Literature, Printing Press and Finished Goods are the areas under this division.
Single sided PCB blanks- having circuit pattern on one side of the board and double sided- having circuit pattern on both sides of the board are manufactured in house. However, Multi-layered PCBs, having many layers of circuit, are obtained from other sources.
Magnetic department makes all type of transformers & coils that are used in
different equipment. Coils and transformers are manufactured as per various specifications such as number of layers, number of turns, types of windings, gap in core, dielectric strength, insulation between layers, electrical parameters, impedance etc. laid down in the documents released by the D&E department.
IS Department is responsible for BEL’s own home grown manufacturing and control systems called BELMAC.it comprises of almost all modules a modern ERP systems but is Host and dumb terminal based.
FINANCE & ACCOUNTS
The F&A division is divided into Budget & Compilation, Cost and Material Accounts, Bills Payable, Bill Receivable, Payrolls, Provident Fund, Cash Sections.
PERSONAL & ADMINISTRATION DEPARTMENT
There are at present about 2300 employees at BEL Ghaziabad, of which more than 400 are graduate and postgraduate engineers.
P&A Division is divided into various departments like Recruitment, Establishment, HRD, Welfare, Industrial Relations, Security and MI Room.
MANAGEMENT SERVICES
This department deals with the flow of information to or from the company. It is Broadly classified into three major sub-sections – Management Information System, Industrial Engineering Department and Safety.
TEST EQUIPMENT AND
AUTOMATION
:
This department deals with the various instruments used in BEL. There are 300 equipments and they are of 16 types.
Examples of some test equipments are: Oscilloscope(CRO)
Multimeter Signal Analyzer Logical Pulsar Counter
Function Generator etc.
Mainly the calibration of instruments is carried out here. They are compared with the standard of National Physical Laboratory (NPL). So, it is said to be one set down to NPL. As every instrument has a calibration period after which the accuracy of the instrument falls from the required standards. So if any of the instruments is not working properly, it is being sent here for its correct calibration. To calibrate instruments software techniques are used which includes the program written in any suitable programming language. So it is not the calibration but programming that takes time .For any industry to get its instrument calibrated by NPL is very costly, so it is the basic need for every industry to have its own calibration unit if it can afford it.
Test equipment and automation lab mainly deals with the equipment that is used for testing and calibration .The section calibrates and maintains the measuring instruments mainly used for Defense purpose.
A calibration is basically testing of equipment with a standard parameter. It is done with the help of standard equipment should be of some make, model and type.
The national physical laboratory (NPL) ,New Delhi provides the standard values yearly. BEL follows International Standard Organization (ISO) standard. The test equipments are
calibrated either half yearly or yearly.
After testing different tags are labeled on the equipment according to the observations.
Green –O.K , Perfect
Yellow – Satisfactory but some trouble is present. Red – Can’t be used, should be disposed off.
The standard for QC, which are followed by BEL are: WS 102 WS 104 PS 520 PS 809 PS 811 PS 369
Where, WS = Workmanship & PS = Process Standard
After the inspection of cables, PCB’s and other things the defect found are given in following codes.
A --- Physical and Mechanical defects. B --- Wrong Writing
C --- Wrong Component / Polarity D --- Wrong Component / Mounting E --- Bad Workmanship/ Finish F --- Bad Soldering
G --- Alignment Problem H --- Stenciling
I --- Others (Specify)
J --- Design & Development
After finding the defect, the equipment is sent to responsible department which is rectified there.
MAGNETICS
In this department different types of transformers and coils are manufactured , which are used in the various defense equipments i.e. radar , communication equipments.
This department basically consists of three sections:
1.) PRODUCTION CONTROL :- Basic function of production control is to plan the production of transformer and coils as per the requirement of respective division (Radar and Communication). This department divided into two groups:
(a) Planning and (b) Planning store.
2.) WORKS (PRODUCTION) :- Production of transformers and coils are being carried out by the works departments.
3.) QUALITY CONTROL :- After manufacturing the transformer/coils the item is offered to the inspection department to check the electrical parameters(DCR , No load current , full load current , dielectric strength , inductance , insulation resistance and mechanical dimension as mentioned in the GA drawing of the product.
The D&E department provides all the information about manufacturing a coil and the transformer.
The various types of transformers are as follows :
i) Air cored transformers
ii) Oil filled transformers
iii) Moulding type transformers
iv) P.C.B Mounting transformers
(a) Impedance matching transformers (b) RF transformers
(c) IF transformers
i) E type
ii) C type
iii) Lamination
iv) Ferrite core
v) Toroidal core
Steps involved in the process of manufacturing of transformer/coils:
a.) Preparation of former : Former is made of plastic bakelite comprising a
male and female plates assembled and glued alternately to form a hollow rectangular box on which winding is done.
b.) Winding : It is done with different material and thickness of wire. The
winding has specified number of layers with each layer’s having a specified number of turns. The distance between the two turns should be maintained constantly that is there should be no overlapping. The plasatic layer is inserted between two consecutive layers.
The various types of windings are as follows :
i) Layer Winding ii) Wave Winding iii) Bank Winding
c.) Insulation : For inter-winding and inter layer , various types of insulation
sheets viz. Craft paper , paper , leather , oil paper , polyester film are being used.
d.) Protection : To protect the transformer from the external hazards , moisture ,
MICROWAVE LABORATORY
Microwave lab deals with very high frequency measurements or very short wavelength measurements. The testing of microwave components is done with the help of various radio and communication devices. Phase and magnitude measurements are done in this section. Power measurements are done for microwave components because current and voltage are very high at such frequencies.
Different type of waveguides is tested in this department like rectangular waveguides, circular waveguides. These waveguides can be used to transmit TE mode or TM mode. This depends on the users requirements. A good waveguide should have fewer loses and its walls should be perfect conductors. In rectangular waveguide there is min. distortion. Circular waveguides are used where the antenna is rotating. The power measurements being done in microwave lab are in terms of S- parameters. Mainly the testing is done on coupler and isolators and parameters are tested here.
There are two methods of testing:
1. Acceptance Test Procedure(ATP) 2. Production Test Procedure(PTP)
Drawing of various equipments that are to be tested is obtained and testing is performed on manufactured part. In the antenna section as well as SOHNA site various parameters such as gain ,bandwidth ,VSWR , phase ,return loss, reflection etc. are checked. The instruments used for this purpose are as follow: 1. Filters 2. Isolators 3. Reflectors 4. Network Analyzers 5. Spectrum Analyzers
6. Amplifiers and Accessories
P.C.B. FABRICATION
P.C.B. stands for Printed Circuits Board. It’s an integral part of the Electronics equipment as well as all the components are mounted on it. It Consists of the
fiberglass sheet having a layer of copper on both sides.
TYPES OF PCBs
Single Sided Board : Circuits on one side. Double Sided Board : Circuit on Both side.
Muti-layer Board : Several layers are interconnected through hole metalization.
Raw material for PCB’s
Most common raw material used for manufacturing of PCBs is copper cladded glass epoxy resin sheet. The thickness of the sheet may vary as 1.2, 2.4 and 3.2mm and the standard size of the board is 610mm to 675mm.
Operation in process
Following steps are there for PCB manufacturing :-CNC Drilling
1. Drill Location
2. Through Hole Plating 3. Clean Scrub and Laminate 4. Photo Print
5. Develop 6. Cu electroplate 7. Tin electroplate 8. Strip
Etching and cleaning Tin Stripping
Gold plating
Liquid Photo Imageable Solder Masking (LPISM) Photo print
Develop
Thermal Baking Hot Air leaving
Non Plated Hole Drilling Reverse Marking
Sharing & Routing Debarring & Packing
P.C.B. is a non-conducting board on which a conductive board is made. The base material, which is used for PCB plate are Glass Epoxy, Bakelite and Teflon etc.
Procedure for through hole metallization
Loading-Cleaner-Water Rinse-Spray Mild Etch-Spray Water-Rinse-Hydrochloric Acid-Actuator-Water Rinse-Spray Water-Rinse-Accelerator Dip-Spray Water- Rinse- Electrolyses Copper-Plating-Plating- Spray water-Rinse-Anti Tarnish Dip-Hot Air Drying- Unloading.
After through hole metallization, photo tool generation is done which is followed by photo printing. In this the PCB is kept b/w two blue sheets and the ckt. is printed on it. A negative and a positive of a ckt. are developed. To identify b/w the negative and positive, following observation is done. If the ckt. is black and the rest of the sheet is white, it is positive otherwise negative.
Next, pattern plating is done. The procedure for pattern plating follows :
Loading- Cleaner- Water rings- Mild etch- Spray- Water Rinse-Electrolytic- Copper plating- Water rinse- Sulfuric acid-Tin plating- Water rinse- Antitarnic dip- Hot air dry- Unloading.
To give strength to the wires so that they can not break. This is done before molding. Varnishing is done as anti fungus prevention for against environmental hazard. After completion of manufacturing proceeds it is sent for testing. This is followed by resist striping and copper etching. The unwanted copper i.e. off the tracks is etched by any of the following chemicals. After this, tin is stripped out from the tracks.
After this solder marking is done. Solder marking is done to mark the tracks to get oxidized & finally etch. To prevent the copper from getting etched & making the whole circuit functionally done.
There are three types of solder marking done in BEL:
Wet solder mask: Due to some demerits this method is totally ruled out. The demerit was
non- alignment, which was due to wrong method applied or wrong machine.
Dry pin solder mask: Due to wastage of films about 30% this method is also not used now.
Liquid photo imaginable solder mask (LPISM): In this first presoaking is at 80 degree Celsius for 10 to 20 minutes. Next, screen preparation is done. The board is covered by a silk cloth whose mesh is T-48. The angle to tilt of the board is 15 degree to 22.5 degree.
The next is ink preparation: Ink + Hardener
71 % : 29 % (150 gms.) : (300gms.)
+
Butyrate solo solve 50gms/kg. Ink
preparation-It uses :-Ink---100gm
Catalyst----10% of total weight
Reducer---10% of total weight
The catalyst is used as binder and prevents the following, while reducer is used as thinner. The three things are then fully mixed.
For wash out, following procedure takes place.
Water-Lactic acid-Water-Bleaching power-Water-caustic Soda-Water-Air dry-TCE.
After wash out, final baking for one hour at the temt. of 20degree C is done. After this shearing or routing is done which is followed by debarring and packing.
QUALITY CONTROL
(WORK ASSEMBLY)
According to some laid down standards, the quality control department ensures the quality of the product. The raw materials and components etc. purchased and inspected according to the specifications by IG department. Similarly QC work department inspects all the items manufactured in the factory. The fabrication department checks all the fabricated parts and ensures that these are made according to the part drawing, painting , plating and stenciling etc are done as per BEL standards.
The assembly inspection departments inspects all the assembled parts such as PCB , cable assembly ,cable form , modules , racks and shelters as per latest documents and BEL standards .
The mistakes in the PCB can be categorized as: 1. D & E mistakes
2. Shop mistakes 3. Inspection mistakes
The process card is attached to each PCB under inspection. Any error in the PC is entered in the process card by certain code specified for each error or defect.
After a mistake is detected following actions are taken: 1. Observation is made.
2. Object code is given. 3. Division code is given. 4. Change code is prepared.
WORK ASSEMBLY
This department plays an important role in the production. Its main function is to assemble various components, equipments and instruments in a particular procedure.
It has been broadly classified as:
WORK ASSEMBLY RADAR e.g. INDRA –II, REPORTER.
WORK ASSEMBLY COMMUNICATION e.g EMCCA, MSSR, MFC.
EMCCA:EQUIPMENT MODULAR FOR COMMAND CONTROL
APPLICATION.
MSSR: MONOPULSE SECONDARY SURVEILLANCE RADAR.
MFC: MULTI FUNCTIONAL CONSOLE.
The stepwise procedure followed by work assembly department is: 1. Preparation of part list that is to be assembled. 2. Preparation of general assembly.
3. Schematic diagram to depict all connections to be made and brief idea about all components.
4. Writing lists of all components.
In work assembly following things are done :
M
aterial Receive:
Preparation- This is done before mounting and under takes two procedures.
Tinning- The resistors ,capacitors and other components are tinned with the help of
tinned lead solution .The wire coming out from the components is of copper and it is tinned nicely by applying flux on it so that it does not tarnished and soldering becomes easy.
Bending- Preparation is done by getting the entire documents , part list drawing and
Mounting- It means soldering the components of the PCB plate with the help of
soldering tools. The soldering irons are generally of 25 W and are of variable temperature, one of the wires of the component is soldered so that they don’t move from their respective places on the PCB plate. On the other hand of the component is also adjusted so that the PCB does not burn.
Wave Soldering- This is done in a machine and solder stick on the entire path, which
are tinned.
Touch Up- This is done by hand after the finishing is done. Cleaning:
Inspection- This comes under quality work.
Heat Ageing- This is done in environmental lab at temperature of 40 degree C for 4
hrs and three cycles.
Testing:
Lacquering- This is only done on components which are not variable.
Storing- After this variable components are sleeved with Teflon. Before Lacquering
mounted plate is cleaned with isopropyl alcohol. The product is then sent to store.
RADAR
(RADIO DETECTION AND RANGING)
INTRODUCTION
Radar is an electromagnetic system for the detection and location of reflecting objects such as aircrafts, ships, spacecraft, vehicles, peoples and the natural environment. It operates by radiating energy into space and detecting the reflected echo signal from an object, or target. The reflected energy to the radar not only indicates the presence of a target, but by comparing the received echo signal with the signal that was transmitted, its location can be determined along with other target related information. Radar can perform its function at long or short distances and under conditions impervious to optical and infrared sensors. It can operate in darkness, haze, fog, rain and snow. Its ability to measure the distance with high accuracy and in all weather is one of its most important attributes. Although most of the radar units use microwave frequencies, the principle of radar is not confine to any particular frequency range. There are some radar units that operate on frequencies well below 100 MHz and others that operate in the infra-red range and above.
RADAR DEVELOPMENT
Although the development of radar as a full-fledged technology did not occur until World War-II, the basic principle of radar detection is almost as old as the subject of electromagnetism itself. Heinrich Hertz, in 1886, experimentally tested the theories of Maxwell and demonstrated the similarity between radio and light waves. Hertz showed that radio waves could be reflected by metallic and dielectric bodies. It is interesting to know that although Hertz’s experiments were performed with relatively short wavelength radiation (66 cm), later work in radio engineering was almost entirely at longer wavelengths. The shorter wavelengths were not actively used to any extent until the late thirties. One of the biggest advocators of radar technology was Robert Watson-Watt, a British scientist.
Several inventors, scientists, and engineers contributed to the development of radar. The use of radio waves to detect "the presence of distant metallic objects via radio waves" was first implemented in 1904 by Christian Hülsmeyer, who demonstrated the feasibility of detecting the presence of ships in dense fog and received a patent for radar as Reichspatent Nr. 165546. Another of the first working models was produced by Hungarian Zoltán Bay in 1936 at the Tungsram laboratory.
While radar development was pushed because of wartime concerns, the idea first came about as an anti-collision system. After the Titanic ran into an iceberg and sank in 1912, people were interested in ways to make such happenings avoidable.
The term RADAR was coined in 1941 as an acronym for Radio Detection and
Ranging. The name reflects the importance placed by the workers in this field on the
need for a device to detect the presence of a target and to measure its range. This acronym of American origin replaced the previously used British abbreviation RDF (Radio Direction Finding).
Although modern radar can extract more information from a target’s echo signal than its range, the measurement of range is still one of its most important functions. There are no competitive techniques that can accurately measure long ranges in both clear and adverse weather as well as can radar.
BASIC PRINCIPLE
An elementary form of radar consists of a transmitting antenna emitting electromagnetic radiation generated by an oscillator of some sort, a receiving antenna, and an energy-detecting device, or receiver. A transmitter generates an electromagnetic signal (such as a short pulse of sine wave) that is radiated into space by an antenna. A portion of the transmitted energy is intercepted by the target and reradiated in many directions. The reradiation directed back towards the radar is collected by the radar antenna, which delivers it to a receiver. There it is processed to detect the presence of the target and determine its location. A single antenna is usually used on a time-shared basis for both transmitting and receiving when the radar waveform is a repetitive series of pulses. The range, or distance, to a target is found by measuring the time it takes for the radar signal to travel to the target and return back to the radar. (Radar engineers use the term range to mean distance) The target’s
location in angle can be found from the direction the narrow -beamwidth radar antenna points when the received echo signal is of maximum amplitude. If the target is in motion, there is a shift in the frequency of the echo signal due to the Doppler effect. This frequency shift is proportional to the velocity of the target relative to the radar (also called the radial velocity). The Doppler frequency shift is widely used in radar as the basis for separating desired moving targets from fixed (unwanted) “clutter’ echoes reflected from the natural environment such as land, sea, or rain. Radar can also provide information about the nature of the target being observed.
ECHO AND DOPPLER SHIFT
Echo is something you experience all the time. If you shout into a well or a canyon, the echo comes back a moment later. The echo occurs because some of the sound waves in your shout reflect off of a surface (either the water at the bottom of the well or the canyon wall on the far side) and travel back to your ears. The length of time between the moments you shout and the distance between you and the surface that creates the echo determines the moment that you hear the echo.
Doppler shift is also common. You probably experience it daily (often without realizing it). Doppler shift occurs when sound is generated by, or reflected off of, a moving object. Doppler shift in the extreme creates sonic booms (see below). Here's how to understand Doppler shift (you may also want to try this experiment in an empty parking lot). Let's say there is a car coming toward you at 60 miles per hour (mph) and its horn is blaring. You will hear the horn playing one "note" as the car approaches, but when the car passes you the sound of the horn will suddenly shift to a lower note. It's the same horn making the same sound the whole time. The change you hear is caused by Doppler shift.
TYPES OF RADAR
Based on function radar can be divided into two types: PRIMARY OR SIMPLE RADAR
Primary radar or the simple radar locates a target by procedure described in section. But in cases as controlling of air traffic, the controller must be able to identify the aircraft and find whether it is a friend or foe. It is also desired to know the height of aircraft.
To give controller this information second radar called the “SECONDARY SURVEILLANCE RADAR”, (SSR) is used. This works differently and need the help of the target aircraft it séance out a sequence of pulses to an electronic BLACK BOX called the TRANSPONDER, fitted on the aircraft. The transponder is connected to the aircrafts altimeter (the device which measures the planes altitude) to transmit back the coded message to the radar about its status and altitude. Military aircrafts uses a similar kind of radar system with secrete code to make sure that it is friend or foe, a hostile aircraft does not know what code to transmit back to the ground station for the corresponding receiver code.
IFF UNIT
IFF is basically a radar bacon system employed for the purpose of general
identification of military targets .The bacon system when used for the control of civil air traffic is called as SECONDARY SURVEILLANCE RADAR (SSR).
Primary radar locates an object by transmitting signal and detecting the
reflected echo. A secondary radar system is basically very similar to primary radar system except that the returned signal is radiated from the transmitter on board the target rather then by reflection, i.e. it operates with a cooperative ‘active’ target while the primary radar operates with “passive target’.
Secondary radar system consists of an interrogative and a transponder. The interrogator transmitter in the ground station interrogates transponder equipped aircraft, providing two way data communication on different transmitter and receiver frequency. The transponder on board the aircraft on receipt of a chain of pulses from ground interrogator, automatically transmit the reply, coded for the purpose of identification, is received back to the ground interrogator where it is decoded and displayed on a radar type presentation.
ADVANTAGES OF SSR OVER PRIMARY RADAR
Separate transmitting and receiving frequencies eliminate ground and whiter return problems.
Reply pulses are stronger then echo signal of primary radar. Reply signal is independent of the target cross section.
Interrogation and reply path coding provide discrete target identification and altitude.
The interrogate and reply mode works on the L band at 1030 MHz and the airborne transponder works at 1090 MHz.
The SSR operates on the same frequency channel for both military and civil air traffic control by using compatible airborne aircraft
Basic Radar System
A basic radar system is spilt up into a transmitter, switch, antenna, receiver, data recorder, processor and some sort of output display. Everything starts with the transmitter as it transmits a high power pulse to a switch, which then directs the pulse to be transmitted out an antenna. Just after the antenna is finished transmitting the pulse, the switch switches control to the receiver, which allows the antenna to receive echoed signals. Once the signals are received the switch then transfers control back to the transmitter to transmit another signal. The switch may toggle control between the transmitter and the receiver as much as 1000 times per second.
Any received signals from the receiver are then sent to a data recorder for storage on a disk or tape. Later the data must be processed to be interpreted into something useful, which would go on a Pulse Width and Bandwidth:
Some radar transmitters do not transmit constant, uninterrupted electromagnetic waves. Instead, they transmit rhythmic pulses of EM waves with a set amount of time in between each pulse. The pulse itself would consist of an EM wave of several
wavelengths with some dead time after it in which there are no transmissions. The time between each pulse is called the pulse repetition time (PRT) and the number of pulses transmitted in one second is called the pulse repetition frequency (PRF). The time taken for each pulse to be transmitted is called the pulse width (PW) or pulse duration. Typically they can be around 0.1 microseconds long for penetrating radars or 10-50 microseconds long for imaging radars (a display. microsecond is a millionth of a second).
Mathematically,
PRT = 1 / PRF
or
PRF = 1 / PRT
WORKING OF A SIMPLE RADAR
A radar system, as found on many merchants’ ships, has three main parts:
The antenna unit or the scanner
The transmitter receiver or ‘transceiver’ and
The visual display unit
The antenna is two or three meter wide and focuses pulses off very high frequency radio energy into a narrow vertical beam. The frequency of the radio waves is basically about 10,000 MHz. The antenna is rotated at the rate of 10 to 25 rpm so that radar beam swaps through 300degree Celsius all around the ship out to a range of about 90 kms.
In all radar it is vital that the transmitting and the receiving in a transceiver are in close harmony. Every thing depends on accurate measurement of the time
that passes between the transmission of pulse and the return of the echo. About 1000, pulses per second are transmitted. Though it is varied to suit the requirements. Short pulses are best for short-range work, longer pulses are best for longer-range work.
An important part of transceiver circuit is ‘modular circuit’. This ‘keys’ the transmitter so that it oscillates, or pulses for the right length of time. The pulses so designed are ‘video pulses’. These pulses are short range pulses hence can’t serve out the purpose of long range work .In order to modify these pulses to long range pulses or the RF pulses, we need to generate the power. The transmitted power is generated in a device called the “magnetron” which can handle all these short pulses and very high oscillations.
Between these pulses, the transmitter is switched off and isolated. The weak echoes from the target are picked up by the antenna and fed into the receiver. To avoid overlapping of these echoes with the next transmitted pulse, another device called ‘duplexer’ is used. Thus by means of the duplexer, undisturbed two-way communication is established. The RF echoes emerging from the duplexer are now fed to the mixer where they are mixed with the RF energy. These pulses are generated by the means of a local oscillator. Once two are mixed, a signal is produced in the output which is of intermediate frequency range or IF range .The IF signal is received by the receiver by the receiver where it is demodulated to video frequency signal range, amplified, and then passed to the display system.
The display system usually carried out the control necessary for the operation of whole radar .It has a cathode ray gun, which consists of a electron gun in its neck. The gun shouts electron to the phosphorescent screen at the far end. Phosphorescent screen glows when hit by an electron and the resulting spot can be seen through the glass face.
The screen is circular in shape and I calibrated in the edges .The electron beam travels from the center of the edge. This radio motion of the electron is known as trace is matched with the rotation of the antenna. So when the calibration is at zero degree on the tube calibration, the antenna is pointing to the dead ahead. The beginning of each trace corresponds exactly which the moment at which the suppression radar energy is transmitted.
The basic idea behind radar is very simple: a signal is transmitted, it bounces off an object and some type of receiver later receives it. They use certain kinds of electromagnetic waves called radio waves and microwaves. This is where the name RADAR comes from (Radio Detection And Ranging). Sound is used as a signal to detect objects in devices called SONAR (Sound Navigation Ranging). Another type of signal used that is relatively new is laser light that is used in devices called LIDAR (Light Detection And Ranging).
Once the radar receives the returned signal, it calculates useful information from it such as the time taken for it to be received, the strength of the returned signal, or the change in frequency of the signal
.
RADAR EQUATION
The amount of power Pr returning to the receiving antenna is given by the radar
equation:
where
• Pt = transmitter power
• Gt = gain of the transmitting antenna
• Ar = effective aperture (area) of the receiving antenna
• σ = radar cross section, or scattering coefficient, of the target
• F = pattern propagation factor
• Rt = distance from the transmitter to the target
• Rr = distance from the target to the receiver.
In the common case where the transmitter and the receiver are at the same location, Rt
This shows that the received power declines as the fourth power of the range, which means that the reflected power from distant targets is very, very small.
The equation above with F = 1 is a simplification for vacuum without interference. The propagation factor accounts for the effects of multipath and shadowing and depends on the details of the environment. In a real-world situation,
pathloss effects should also be considered.
APPLICATIONS OF RADAR
Radar has been employed on the ground, in the air, on the sea and in space. Ground – based radar has been applied chiefly to the detection, location, and tracking of the aircraft or space target. Shipboard radar is used as a navigation aid and safety device to locate buoys, shorelines and other ships as well as for observing aircraft. Airborne radar may be used to detect other aircraft, ships, or land vehicles or it may be used for mapping of land, storm avoidance, terrain avoidance and navigation. In space, radar has assist in the guidance of spacecraft and for remote sensing of the land and sea.
The major use of radar, and contributor of the cost of almost all of its development, has been the military; although there has been increasingly important civil application, chiefly for marine and air navigation. The major areas of radar application are briefly described below: