Focus- - DRDO RADAR Power

[JAISWAL]

Radar power
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FOCUS:- DRDO Radar power
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By- T.S. SUBRAMANIAN
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The LRDE, a premier laboratory of the DRDO, develops a range of radar systems to meet the requirements of the defence forces.
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THE scene is a "bunker" on the wooded campus
of the Electronics and Radar Development
Establishment (LRDE), one of the premier
laboratories of the Defence Research and
Development Organisation (DRDO), in Bangalore.
A radar is positioned near the bunker's window
to face the road. Its piercing eyes detect and track
a man walking a few kilometres away and the
image immediately looms into view on a
computer monitor. When the moving target
quickens its pace, the rhythm is reflected on the
monitor. When a man is caught crawling a few
100 metres away, the image on the monitor
captures the slow motion.
The man-portable, battery-operated Battlefield
Surveillance Radar – Short Range (BFSR-SR), has
become a hit with the Army. Weighing just 30
kg, it can be brought into operation in a battlefield
in about five minutes. It can detect, track and
classify a variety of ground-surface targets within
a detection range of 700 metres to eight
kilometres. So far, 1,441 BFSRs have been
delivered to the Army and 90 to the Border
Security Force (BSF). Bharat Electronics Limited
(BEL), Bangalore, manufactures this radar.
"We developed the BFSR in two years to the
specific requirements of the Army. The mandate
was that it should be deployable in hilly, snow-
bound high-altitude areas, should withstand very
low temperatures, and be light in weight," said S.
Varadarajan, Director, LRDE. There was a felt
need during the Kargil conflict in 1999 to develop
a short-range radar to alert the Army about
enemy intrusions on high-altitude terrain.
"Driving Rain Chamber", reads the quizzical
legend on a box-like contraption in a building that
houses the many-chambered Quality and
Reliability Assurance Division on the campus. As
the doors of the "Driving Rain Chamber" swing
open, we find the central processing unit (CPU),
the heart of a radar system, being drenched in
the "rain" that issued forth from within the
chamber. The CPU was being battered as part of
the quality and reliability check to prove the
radar's ruggedness. The CPU processes the data
received by the radar, senses the target with the
help of an antenna, and sends it for display. It can
classify the enemy too.
The building contains Combined Altitude,
Temperature and Humidity (CATH) chambers,
thermal shock chambers, dust chambers,
corrosion chambers, and so on, where the
various parts of radars are tested thoroughly
before the systems are deployed in the field. The
thermal shock chamber has three compartments.
In the "cold" compartment, the temperature
ranges from -700 Celsius to +800 C and in the
hot cell, it ranges from 00 C to 2000 C. The third
compartment has ambient temperature. The
airborne radar systems are tested in these
temperatures because when an aircraft climbs to
an altitude of 40,000 feet (12,000 metres), the
transition time from the ambient temperature to
freezing cold is only 10 minutes. The airborne
radar systems should withstand these thermal
shocks. Even the gear box of India's Light Combat
Aircraft (LCA), Tejas, was tested in the CATH
chambers.
The 60-foot long, 40-foot broad and 32-foot tall
anechoic chamber was set up in 1987 to test the
equipment on the Arjun battle tank and later that
in Tejas and in India's nuclear-powered
submarine, Arihant. It is now used to test the
radar equipment. "Any equipment should be
compliant with electromagnetic interference [EMI],
which cannot be eliminated," explained D.C.
Pandey, Outstanding Scientist, LRDE, who is also
India's foremost expert in EMI and
electromagnetic compatibility (EMC). "You can
reduce the EMI to a particular level and that level
depends on the platform [on which the
equipment is integrated]." These platforms are
ships, aircraft, submarines, satellites and the
ground. In the anechoic chamber, the
electromagnetic field is amplified and measured.
"We amplify the field and measure the effect, and
make sure that the equipment is immune to the
harsh electromagnetic environment," Pandey
said.
With the radar systems undergoing such a
battery of tests, it is not surprising that
Varadarajan asserted: "The radars, developed by
the LRDE, are performance-wise on a par, if not
better than, with the best in the world. The armed
forces place repeat orders with BEL for a range of
radars, including BFSR-SR, Rohini and Rajendra.
Today, we are totally focussed on the
development of radars for the three armed
forces. We want the radars we develop to
become globally competitive because the Army
has the option to shop anywhere," he said. The
LRDE has developed the primary radar for the
indigenous Airborne Early Warning and Control
System (AEW & CS), which helps in tactical
missions against enemy aircraft or in deep
penetration strikes. The AEW & CS was tested
during its maiden flight on a modified Embraer
aircraft in Brazil on December 6, 2011. Tejas uses
the antenna developed by the LRDE.
W. Selvamurthy, Chief Controller (Life Sciences),
DRDO, is proud of the galaxy of radar systems
developed by the LRDE. They include the BFSR-
SR; the weapons-locating radar (WLR) Swathi; the
lightweight Bharani for the Army's air defence;
Aslesha for the Indian Air Force (IAF); Rohini, the
backbone of India's air defence; Revathi, the
surveillance radar for the Navy; Rajendra, a
phased-array radar, which is the core of Akash,
India's surface-to-air missile system; the airborne
maritime patrol radar, which has been integrated
into India'a Advanced Light Helicopter; the Navy's
Kamov-25 helicopter and the Coast Guard's
Dornier aircraft; and the ground-penetration radar
for locating buried mines, improvised explosive
devices (IEDs) and unexploded ordnances (UXOs).
BEL is the LRDE's "production buddy" for all the
radars. The LRDE has now plunged into the
development of a "through wall looking radar",
which can do remote three-dimensional (3D)
imaging of terrorists hiding behind walls and
detect even their heartbeats.
The DRDO, with 52 laboratories located in
different parts of the country, is one of the largest
enterprises of its kind catering to the Indian
armed forces. Selvamurthy estimated that the
production value of the products developed by
the DRDO in the last eight years was around
Rs.1,60,000 crore. The Army has placed orders
for 124 Arjun-Mark I main battle tanks, developed
by the DRDO's Combat Vehicles Research and
Development Establishment (CVRDE) situated at
Avadi near Chennai. Each Arjun tank cost Rs.18
crore, Selvamurthy said. The Army has placed
orders for a batch of 124 Arjun-Mark II battle
tanks too, which will feature a number of
modifications on Mark-I. The IAF has placed
orders for 40 Tejas aircraft, each costing more
than Rs.150 crore.

 

[JAISWAL]

part- 2
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Production orders in the past eight years for
products developed by the DRDO to counter
nuclear, biological and chemical warfare agents
are valued at Rs.800 crore. They include gamma
flash sensors, dosimeters, roentgenometers,
reconnaissance vehicles, water purification filters,
nerve-agent detectors and underground shelters.
In the field of radars, the DRDO's customers are
well-defined: the Army, the Navy and the Air
Force. The Army's requirements are demanding:
the radars should be light enough to be
transported and capable of being assembled or
dismantled quickly.
Varadarajan said: "Today, there is an inclination
among the Services to use Indian radars because
we match their requirements. The goal of our
laboratory is to develop the key technologies
required for radars, keeping in view the products
required over the next decade, and to synergise a
partnership between public sector and private
units and quickly develop the products." This
requires the right blend of engineering and
electronics and an understanding of the specific
environment in which the radars have to be
deployed. LRDE engineers are engaged in
concurrent engineering with their counterparts in
the private sector. The LRDE is partnering a
network of private units, which had invested in
the development of specific subsystems,
including microwave tube assemblies, fabrication
of material needed for antennae, compact and
rugged power packs, and cooling units.
Varadarajan said: "These private units
manufacture quality products needed for radars,
benchmarking themselves against established
foreign vendors. Today, these industries are able
to design subsystems against stringent
requirements by the armed forces. The net result
is that there is a public-private sector partnership
and the items produced in this country,
particularly radars, remain globally competitive.
We have been able to cut down the development
time for many of the radars because we unearth
private partners who can take part in the
development, we adhere to concurrent
engineering, and there is a mechanism for
production. We are very much on track. "
The roles of the various radars developed by the
LRDE are impressive.
R. Kuloor, Outstanding Scientist, LRDE, explained
that the BFSR located the position of the target
with the help of electromagnetic waves and
displayed the image of the target on the control
and display unit. So the radar can be left
unattended, he said. "We can see the action in
real time." As he was talking the audio Doppler
picked up the sound of the siren of an ambulance
that came within its range.
To detect aerial targets such as helicopters,
unmanned aerial vehicles (UAVs), remotely
piloted vehicles (RPVs) or fighter aircraft, the LRDE
has designed a radar system called Bharani. The
radar can be transported in a vehicle, as an
under-slung of a helicopter, or on a mule. The
Army was keen that this kind of short-range
radar should be developed for deployment in
mountainous terrain in Jammu and Kashmir and
in the north-east region, M. Ramanjeneyulu, LRDE
scientist, said.
Bharani weighs 165 kg and its petals can be
assembled in 10 minutes. The Army has accepted
the radar and it is under production. "Bharani can
be installed in any place, even in a bunker and in
uneven places. It can withstand strong winds in
hilly areas," Ramanjeneyulu explained.
The backbone of India's air defence is the vehicle-
mounted Rohini medium-range radar, which can
detect 200 targets simultaneously. It can detect
fixed-wing aircraft flying at a distance of 200 km
at a height of 18 km. It can be deployed and
decamped in 30 minutes. "If Sagar Samrat [the
Oil and Natural Gas Corporation's offshore oil rig
production platform] has to be protected against
aerial attacks, we need this type of radars,"
Varadarajan said.

 

[JAISWAL]

part- 3
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Revathi is a 3D medium-range radar installed on
naval ships. It can detect sea-surface targets 80
km away, fighter-aircraft 150 km away, and
cruise missiles at a distance of 40 km. The
Tactical Control Radar (TCR), an avatar of Rohini,
is built to suit the Army's requirements.
Any modern radar searches for, detects and
tracks a target precisely and provides information
on its speed and height. It does this by
mechanical scanning or by rotating its antenna. In
a phased-array radar, the requirements are even
more stringent.
Rajendra boasts of an electronic scanning array. It
can perform multiple functions – it keeps
surveillance over the sky, searches for the target,
acquires it and tracks it. It can guide in real time 12
Akash missiles towards intruders until the
warhead explodes. Rajendra can simultaneously
do precision tracking of four targets. Its
instrumented range is 80 km and height
coverage is 18 km. It has an IFF system to
identify a target as a friend or foe.
"Rajendra is a success story. The Army and the
Air Force have placed bulk orders for it, probably
the biggest such orders. It has given a fillip to the
Indian defence industry," said Varadarajan.
A derivative of Rajendra is Swathi, which was
developed in the aftermath of the Kargil conflict.
When shells are fired from an enemy artillery gun
or mortar, the WLR will track their trajectory and
thus identify the gun's location. It can locate, in a
few seconds, large mortars positioned 20 km
away and guns positioned 30 km away. "This
radar can see up to seven shells at the same time.
The WLR, in its secondary role, can track the fall
of shots from our own weapons to give
corrections to our fire," said R.V. Narayana,
Project Director of Swathi. Swathi went through
extensive trials at the Army's test range in
Pokhran in Rajasthan and its performance was
found to be among the best in the world, he
added. "We went for concurrent engineering
where the development, user and production
agencies worked together from day one. Within
two months of proving the prototype, the
production model went for user trials," he said.
Swathi has been cleared for production and is
being inducted into the Army.
An ambitious programme under way is the
development of the Arudhra radar system for the
IAF. It has a rotating, electronic scanning array. It
can detect intruding aircraft flying more than 300
km away and at altitudes ranging from 30 m to
30 km. Arudhra is vital for India's air defence and
will be useful for network-centric warfare.
Under development against specific requirement
is a low-level, transportable radar called Ashwini,
for automatic detection and tracking of
helicopters, fixed-wing aircraft, UAVs and RPVs.
Ashwini will take the place of Rohini when the
latter's production is completed.
The LRDE is developing a Coastal Surveillance
Radar (CSR) to track shipping vessels, small boats
and trawlers in rough sea and bad weather
conditions. "This is a challenging area," said
Kuloor. The challenge is in resolution of small-
sized, closely spaced targets in a sea clutter. The
CSR can track even catamarans, which do not
have a big radar cross section. The CSR's
purpose is to track ultra-small objects, resolve
and identify them, Kuloor added. The radar's
coverage is 30 km.
Aslesha has been developed for deployment in
high-altitude areas such as Leh and Kargil. The
system was tested in -300 C in Leh. "It has been
designed in such a way that it can be deployed in
a place where there is no human access," said
Anil Kumar Singh, Scientist, LRDE, and Project
Director, Aslesha. The radar can be assembled in
20 minutes without using a tool. Its various parts
can be snapped together into place. It can be
dismantled into small parts and transported.
Aslesha has 18 antennae and its height coverage
is 20,000 feet (6,000m). "If it is installed on a
hilltop, it can look down. If it is deployed in a
valley, it can look up. What is special is that this
radar is 100 per cent indigenous. All technologies
[that went into its making] were developed in
India," Anil Kumar Singh said. A fibre-optic cable
connects the radar to the operator's computer in
the bunker a kilometre away. It has an IFF
system. The IAF has ordered the supply of 21
Aslesha radars.
Anil Kumar Singh, who is also Project Director for
the Active Electronically Scanning Array (AESA)
radar, called it "an ambitious project". The project
was approved in January. The main role of the
radar, which will be integrated with the fighter
aircraft, is to direct the fire accurately from the
aircraft. It will feature advanced electronic
counter, counter measures (ECCMs). The radar
will direct the fire from air-to-air, air-to-ground
and air-to-sea missiles.
"We have taken a lot of initiatives to bring out
several contemporary radars to meet the
requirements of the Services," Varadarajan said.

 

[JAISWAL]

now from the above artical in part-3 in last para.--
Anil Kumar Singh, who is also Project Director for the Active Electronically Scanning Array (AESA) radar, called it "an ambitious project". The project was approved in January. The main role of the
radar, which will be integrated with the fighter aircraft, is to direct the fire accurately from the aircraft. It will feature advanced electronic counter, counter measures (ECCMs). The radar will direct the fire from air-to-air, air-to-ground and air-to-sea missiles.
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In here we can see that it is first time an offical confermation of ongoing AESA project and implementation is acknowledged.

 

[sayareakd]

too bad they didnt post any info about LRTR which is crown jewel of our radar.

 

[JAISWAL]

THE BATTLEFIELD SURVEILLANCE Radar

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ASLESHA, THE LOW-LEVEL light-weight radar

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THE VEHICLE-MOUNTED mediumrange Rohini radar.