NAME : SIBA PRASAD PRADHAN
SIC NO. : ET103350
REGD N0. : 1001209328
SEMINAR PRESENTATION ON
HOW DOES IT WORKS?
ELEMENTS OF MISSILE DEFENCE
PHASES OF INTERCEPTION
BOOST PHASE INTERCEPT
TERMINAL PHASE INTERCEPT
Interceptor misssile is an anti-ballistic designed to counter the
ballistic missiles like intermediate range and intercontinental ballistic
missiles(more then 10,000 km) .
Interceptors may or maynot carry warhead aims at destroying target
with impact of collison.
United States(Patriot and THAAD), Russia, France, India(PAD &
AAD) and Israel(Arrow and Iron Dome) have all developed missile
Interceptor operates in 3 to 8 mach speed with range 80 to 500 km.
Interceptors can be launched from air , sea or land depending on
phase it is in.
Upgraded Early-warning Radar (UEWR)
This is a phased-array surveillance radar that can
detect and track ballistic missiles.UEWRs will be used to
detect and track missiles and other projectiles during
their midcourse phase, before cueing the more precise X-
Band Radar. Operate in the VHF/UHF range (typically
This consists of a multi-function phased array radar that uses
high frequency (typically 8-12 ghz).The XBR will discriminate
decoys and warheads.The high-resolution accurately discriminate
between closely spaced objects. XBR radar has a 50-degree field
of view and can rotate 360 degrees to track targets. It will
transmit a radiation pattern in a narrow beam made up of
electromagnetic pulses. The radar site consists of the X-band
radar mounted on a pedestal, a control and maintenance facility,
a power generation facility and a 492-foot (150-m) protected
area. The XBR site will cover 17.46 acres.
Space-based Infrared System(SBIRS)
There are three kinds of SBIRS satellites, including
four geostationary earth orbit (GEO) satellites,
twohighly elliptical orbit (HEO) satellites and an
unspecified number of low earth orbit (LEO) satellites.
Eventually, there will be a 24-satellite constellation that
will start tracking enemy missiles earlier than radar,
allowing for quicker response
Ground-based Interceptors (GBIs)
The Ground-Based Interceptor (GBI) is a component
of the Ground-Based Midcourse Defense (GMD)
System. It is launched from a silo and intercepts
ballistic missiles in their midcourse, while they are
outside of the atmosphere and at their highest
trajectory. The GBI consists of a multi-stage rocket
booster (BV – Boost Vehicle) and a kinetic kill
vehicle (EKV – Exoatmospheric Kill Vehicle),
Phase can last 20 minutes and provide good window for interception.
Utilizes an Exo-atmospheric Kill Vehicle (EKV) to destroy the incoming target
using hit-to-kill technology.
Defense Support Program (DSP) satellites;
Space Based Infrared System-High (SBIRS-High)
satellites; the Space Tracking and Surveillance
System (STSS); Upgraded Early Warning Radars
(UEWRs); a Battle Management, Command,
Control and Communications (BMC3) unit; the Sea-Based X-Band Radar (SBX);
and Ground-Based Interceptor (GBI) missiles work together for providing complete
Range is detected using radar equations.
E_s = E_o sigma/R^2 dOmega (transmitted energy)
E_r = E_s A/4pi R^2 = E_o A^2 sigma/(4pi R^4 lambda^2)=NkT
Interceptors have to diffrentiate between decoys and actual warhead.
The XBR will track missiles as they fly closer to the missiles intended target
and assess which missiles are decoys and which are armed with warheads.
ICBM warheads are highly visible to radar and to optical sensors, because of the very
hot "wake" produced by the Mach-23 RV as it enters the atmosphere.
Decoys and light chaff are no longer effective against sensors, because they will be
retarded or destroyed on reentry.
Interceptors must be of high speed compared to the RVs .
Multiple Interceptors are used in this phase as it is necessary to hit the target.
Radars must be more closely spaced to see RVs down to altitudes of reentry, and
interceptors cannot drive out hundreds or thousands of km through the atmosphere.
Probability thatdefense will destroy all targets (a “leak-proof” defense) can be represented by the
P = Probability of leak-proof defense
p = Probability that interceptor will hit target8
n = Number of interceptors fired at each target
N = Number of targets
One can use this equation in order
P = (1-(1-p)^n)^N
Deploying of interceptors adds a big leap towards a countries defense.
It’s brings in cost reduction in Defense purchase and development.
Countermeasures provides high security against any nuclear war.
For countries under NPT (like India) missile defence technology provides greater scope
of defence against any nuclear warhead.
The field of ballistic missile defense is full of fascinating problems of physics and
1- General Accounting Office, “Theater Missile Defense: Significant Technical
Challenges Face the Airborne Laser Program,” GAO/NSIAD-98-37, (Washington D.C.,
U.S. General ACCOUNTING OFFICE, OCTOBER 1997.
2- S. Weiner,"Systems and Technology" in "Ballistic Missile Defense", A.B. Carter and
D.N. Schwartz, Eds. (The Brookings Institution, 1984). This volume is an accessible
compilation of technical and strategic aspects of BMD.
3- Bethe, H.A. and Garwin, R.L. "Anti-Ballistic-Missile Systems," Scientific American
218, 3, pp. 21-31, March 1968.
4- G.E. Forden, IEEE SPECTRUM, Sept. 1997, "The Airborne Laser", pp. 40-49.
5- IEEE SPECTRUM, September 1997, "Ballistic Missile Defense: It's Back", with 5
articles on BMD. Also J. Pike, "Ballistic Missile Defense: Is the U.S. 'Rushing to
Failure?', Arms Control Today, April 1998, Vol. 28, No. 3, p.9-13. (Available at