SUMMER TRAINING PROJECT

ON

INDRA RADAR

MADE BY:-

ISHPREET SINGH

(1041322806)

HASMEET SINGH

(1031322806)

BHARAT ELECTRONICS LIMITED

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 MISSIONTo 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 achieve growth in the operations commensurate with the growth of professional electronics industry in the country.

•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.

PRODUCT RANGES

RADAR SYSTEMS•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.

ROTATION PROGRAMME

Under this the 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 is as follows:

• TEST EQUIPMENT & AUTOMATION• P.C.B FABRICATION• QUALITY CONTROL (WORKS)• MAGNETICS• CS- ELECTRICAL• WORKS ASSEMBLY-RADAR

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.

•It can operate in darkness, haze, fog, rain and snow.

•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.

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.

TYPES OF RADAR

Based on function radar can be divided into two types:•PRIMARY OR SIMPLE RADAR•SECONDARY 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.

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 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 / PRForPRF = 1 / PRT

RADAR EQUATIONThe amount of power Pr returning to the receiving antenna is given by the radar equation:

wherePt = 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 = Rr and the term Rt2 Rr2 can be replaced by R4, where R is the range. This yields:

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.

APPLICATIONS OF RADAR

•Air Traffic Control (ATC): Radar is employed throughout the world for the purpose of safely controlling air traffic route and in the vicinity of Airport. Aircraft and ground vehicular traffic at large airport are monitored by means of high - resolution radar. Radar has been used with GCA (ground control approach) system to guide aircraft to a safe landing in bad weather.

•Ship Safety: Radar is used for enhancing the safety of ship travel by warning of ship potential collision with other ships, and for detecting navigation buoys, especially in poor visibility. Automatic detection and tracking equipment are commercially available for use with radar for the purpose of collision avoidance. Shore – based radar of moderately high resolution is also used for the surveillance of harbors as an aid to navigation.

•Space: Space vehicles have used radar for rendezvous and docking and for landing on the moon. Some of the largest ground based radar is for the detection and tracking of satellite.

•Remote Sensing: All radar is a remote sensor. Radar has been used as a remote sensor of the weather. It is also used to probe the moon and planets. The ionospheric sounder, an important adjunct for HF (short wave) communications, is radar. Remote sensing with radar is also concerned with earth resources, which include the measurement and mapping of sea condition, water resources, ice cover, agriculture, forestry condition, geological information and environmental pollution.

•Law Enforcement: In addition to the wide use of radar to measure the speed of automobile traffic by highway police, radar has also been employed as a means for the detection of intruders.

•Military: Many of the civilian application of the radar are also employed by the military. The traditional role of radar for military application has been for surveillance, navigation and for the control and guidance of weapon.

RADAR MANUFACTURED BY BEL

FLY CATCHERINDRAREPORTERAll the three used for air traffic control and surveillanceAnother radar manufactured by BEL is the CWR or ‘CYCLONE WARNING RADAR’ .

INDRA PC-II

LOW FLYING DETECTION RADAR

• (INDRA II) is fully coherent low-level radar catering to the vital gap-filling role in an air defense environment. It is transportable and self-contained system with easy mobility and deployment features.

•The system consists mainly of an ANTENNA, TRANSMITTER AND DISPLAY CABLE mounted on three separate vehicles.

• A transportable modular mast of 28m can also be used for mounting the antenna for achieving better coverage in a semi-static configuration. Display shelter can be installed up to 100m from the transmitter shelter.

•ANTENNA consists of a PARABOLIC shaped reflector with a flat bottom radiation pattern for avoiding ground clatter. An auxiliary feed caters to improved coverage for short-range targets on reception by avoiding heavy ground clatters .

•The antenna operates from hydraulically elevable 5m masts on the vehicle bed itself. The hosting of the antenna and its folding down for transportation is also carried out hydraulically.

•The electronic equipment of the system is housed in two cables. The transmitter cabin and display cabin. The transmitter cabin contains the transmitter receiver and IFF interrogator.

•The IFF The display cabin contains two identical display consoles as well as processor, primary signal processor, the radar data processor, the centralized radar controls and communication facilities. Both cabins are air-conditioned and inbuilt redundancy and are carried on two separate vehicles.

•SIGNAL PROCESSING is an important part of the system providing good clutter cancellation capabilities. Advance signal processing techniques such as MTD by FFT implementation provide very high improvement factor. I and Q channel processing eliminates blind face problems.

•RADAR DATA PROCESSOR is based on multi micro-processor architecture that accepts both the primary and secondary plots from the signal processor. The tracks are auto-initiated and the process of association and filtering is performed.

•The DISPLAY console incorporates 19inch multi-colored raster scan CRT for presentation of raw/processed videos and track data of RDP.

FEATURES OF SYSTEM

•INTEGRATED FRIEND AND FOE(IFF):

The radar includes integral MK-X equipment. This is a fully solid-state transmitter receiver and the signal processor generates video for presentation on display console as well as plots for processing by RDP.

•COMMUNICATION FACILITES:

Ground-to-air and ground-to-ground communication facilities are available. Facilities also exist for networking the radar with a centralized command on reporting center for effective air defense exploitation.

•BUILT IN TEST EQUIPMENT:

The radar system incorporates up based simulator for injection of test targets right at the receiver input. A number of targets with radial/circular motion can be simulated. The BITE simulator provides an online global system as well as aid for operators training.

SYSTEM CHARACTERISTICS

•RANGE: 90 kms (for fighter aircrafts)

•HEIGHT: 35m to 3000m subject to radar horizon.

•PROBABILITY OF DETECTION: 90% (Single scan).

•PROBABILITY OF FALSE ALARM: 10-6

•TRACK WHILE SCAN (TWS) 2D TRACKING: Capability to handle 200 tracks.

•ASSOCIATION OF PRIMARY AND SECONDARY TARGETS.

•AUTOMATIC TARGET DATA TRANSMISSION TO A DIGITAL MODEM/NETWOKING OF RADARS.

•DEPLOYMENT TIME OF ABOUT 60mins

SIGNAL PROCESSOR UNIT

INTRODUCTION

• The signal processing unit constitutes a very important functional block with vital roles to perform in overall system configuration of INDRA-II the receiver radar returns under normal operating conditions are initially processed by the analogue processing stages (such as LNA, IF, VIDEO DETECTOR etc.) and then processed by signal processor.

•Indra-II being an auto tracking radar has a requirement of automatic target detection, by the signal processor. This type of signal processor is known as MOVING TARGET DETECTOR.

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