GPS guided missiles provide several advantages over older guidance systems. GPS allows missiles to strike targets with pinpoint accuracy from long distances, even in harsh weather conditions or at night, without needing a line of sight to the target. The missile receives GPS signals that provide its precise location and navigation to the programmed target coordinates. Inertial navigation is also used as a backup if GPS signals are lost. Modern missiles can even be pre-loaded with target coordinates from surveillance systems like SAR radar before launch. This makes GPS-guided missiles highly effective "fire and forget" weapons.

1. ADAPTIVE
MISSILE GUIDANCE
Abhilash P
Joy
AU COLLEGE OF ENGINEERING, R&M 2017-
2018

2. CONTENTS
 ABSTRACT
 INTRODUCTION
 MISSILE AND IT’S GUIDANCE
 GNSS, DGPS &WASS
 INERTIAL NAVIGATION SYSTEM
 GPS MISSILE GUIDANCE
 OTHER MAJOR APPLICATIONS OF
GPS

3. ABSTRACT
 In the modern day, the need to strike the target
that are opposite side of the globe are very much
required
 Which leads to guided missiles, which maximise
damage to the target while minimising collateral
damage.
 Fire and forget weapons, with INS and GPS
 Multipath reflections in GPS can be reduced by
narrow correlator spacing. Much less in moving
targets
 So, GPS guided weapons are not affected by
harsh weather conditions or wire limitation.

4. INTRODUCTION
Introduction to Missile Guidance
 Smart warheads will have an increasing role in maintaining
our military superiority
 Deployed warheads will strike only its intended target.
 Our military desires weaponry that is reliable and effective,
maximal damage, lightning fast strikes with pinpoint
accuracy
Introduction to GNSS(GPS)
 GNSS (Global Navigation Satellite System) that provides
autonomous positioning with global coverage
 A GNSS allows electronic receivers to determine their
location (Lat, Lon & Alt) to within a few meters
 Till 2008 the Navstar GPS (Global positioning System) of

5. MISSILE AND IT’S GUIDANCE
MISSILE STRUCTURE
TYPES OF MISSILE GUIDANCE
Radar Signals
Infrared sensing
Wires
Laser Guidance
Most recently GPS

6. GNSS TYPES
(USA)
GPS – 1970
GLONASS –1982
(RUSSIAN )
GALELIO
(EUROPEAN
COUNTRIES)
COMPASS(BEI DOU)
(CHINA)
 IRNSS(INDIA)
 QZSS (JAPAN)
 DORIS (FRANCE)

7.  DEVELOPED BY THE US DEPARTMENT OF
DEFENCE
 24 SATELLITES IN SIX UNIFORMLY SPACED
CIRCULAR ORBITS
 HEIGHT OF SATELLITES 20 183 KM
 SIX ORBITS ARE SPACED 60 DEG APART
 PHASING OF SATELLITE IN EACH ORBIT IS 40 DEG
WRT THE NEXT ORBIT
NAVSTAR - GPS
THREE SEGMENTS
CONTROL SEGMENT SPACE SEGMENT USER
SEGMENT
MASTER CONTROL SATELLITES
SHIPS
AND AIRCRAFT
GROUND ANTENNAE

8. ADVANCEMENTS IN GNSS
(GPS)
DGPS
 United States NDGPS
 European DGPS
 Australia DGPS
 Canadian DGPS
 Indian DGPS
SBAS.
 WAAS(US)
 EGNOS(EUROPEAN)
 GAGAN(INDIA)
 MSAS(JAPAN)
 SDCM(RUSSIA)
 SNAS(CHINA):-planning

9. DIFFERENTIAL GPS
 GPS satellite data is Rx by user & a fixed
station of accurately known position.
 The fixed station compares the range data from
the satellite and known range.

10. Sl.
No.
Name of DGPS
Locations
Sl.No
.
Name of DGPS
Locations
Sl.No
.
Name of DGPS
Locations
Sl.N
o.
Name of DGPSLo
cations
1. Okha 7. Ratnagiri 13. Pandian Tivu 19. Paradeep
2. Porbander 8. Hazira 14. Pulicat 20. Keating Point
3. Gopnath 9. Azhikode 15. Dolphins Nose 21. Campbell bay
4. Uttan 10. Minicoy Island 16. Krishnapatnam 22. East Island
5. Aguada 11. Pondicherry 17. Antervedi 23. Rameshwaram
6. Suratkal 12. Nagapattnam 18. Saugor Island
DGPS STATIONS IN INDIA
The errors are transmitted by MF Beacon ( 285-325
KHz).
The coverage area is 100 - 150 NM.
The position can be fixed by mariners to an accuracy
of better than 5 meter.

11. SBAS
(SATELLITE BASED AUGMANTATION SYSTEMS)

12. DGPS LIKE ERROR CORRECTION IS NOT POSSIBLE IN FAST MOVING
AIRCRAFTS.
SBAS HAS SEVERAL GROUND STATIONS WHICH CONTINOUSLY
MONITOR THE ERROR.
MASTER STATION COLLECTS ALL ERRORS AND UPLINK IT TO GSAT.
GSAT PROVIDES THIS INFORMATION TO A WIDE AREA.
SBAS
Wide Area Augmentation System
(WAAS)
European Geostationary
Navigation Overlay Service
(EGNOS)
MTSAT Satellite Based
Augmentation Navigation System
(MSAS)
GPS-Aided GEO Augmented
Navigation System (GAGAN)
System for Differential

13. INERTIAL NAVIGATION
SYSTEM
 INS senses motion and acceleration in different
directions.
 These devices are called gyroscopes and
accelerometers.
 The purpose of a gyroscope is to measure angular
rotation.
 Accelerometers measure linear motion.

14.  The INS sense motion
relative to a point of origin.
 Inertial navigation works
by telling the missile
where it is at the time of
launch and how it should
move in terms of both
distance and rotation over
the course of its flight
INERTIAL NAVIGATION
SYSTEM
 The missile computer uses signals from the INS to
measure these motions and insure that the missile
travels along its proper-programmed path.

15. HOW MISSILES GUIDED?
 The missile guidance system keeps the
missile on the course that will cause it to
intercept the target.
 The guidance system may be provided with
certain information about the target before
launching.
 During flight it may receive additional
information, either by radio from the
launching site or other control point, or from
the target itself.
 On the basis of this information, the
guidance system will calculate the course
required intercepting the target, and it will

16. MISSILE
GUIDANCE

17. MISSILE LAUNCH & TARGET-
DESTRUCTION PROCESS
 Surveillance
 Identification
 Pre-launch
 Launch
 Tracking
 Midcourse.
 Homing
 Intercept
 (target destruction)

18. MISSILEGUIDANCE USING
GPS
 3-axis gyro/accelerometer - inertial reference
 correcting the accumulated drift error - GPS PPS/P-code.
 CEPs (Circular Error Probable) of the order of the
accuracy of GPS
 GPS weapons – Not for moving targets.
 GPS - very efficient for coordinated attack.
 They are unaffected by weather, target concealment or
countermeasures.
 Modern weapons are more immune to GPS jamming, by
the use of advanced GPS-AJ modules.
 Higher precision by using combined GPS techniques.
 It can be preloaded with target coordinates before the flight

19.  Modern SAR’s are automatically extract target coordinates from the images
they generate.
 The next incremental step is then to update the weapon before launch.
 which will allow it to correct its GPS error as it flies to the target.
 These weapons are "precise" and will offer accuracies greater than laser or
TV guided weapons.
 For an aircraft to support such munitions, it will require a DGPS receiver, a
GPS receiver.
 Unlike a laser-guided weapon - does not require that the launch aircraft
remain in the vicinity of the target.
 GPS/inertial weapons are true fire-and-forget weapons
 Existing precision weapons require an obscured line of sight between the
weapon and the target.
 GPS/inertial weapons are oblivious to the effects of weather, allowing a target
to be engaged at the time of the attacker's choosing.
MISSILEGUIDANCE USING
GPS

20. How GPS effectively used for
Missiles?

21. MISSILEGUIDANCE USING
GPS
 Satellite Guided Weapons
 The problem of poor visibility does not affect JDAM (Joint Direct
Attack Munitions).
 improved accuracy compared and can operate in all weather
conditions.
 It reverts to INS in the event of losing the GPS signal.
 INS less accurate; JDAM CEP of 13 m (GPS) but 30 m under
inertial guidance.
 INS CEP increases as the dropping altitude increases
 The GPS CEP does not increases as the dropping altitude
increases
 . The precision dependent both on the precision of the
measurement system used for location determination and the
precision in setting the coordinates of the target.
 if the targeting information is accurate, satellite-guided weapons
are significantly more likely to achieve a successful strike in any
given weather conditions.

22. CONCLUSION
However the GPS guided weapons are not affected by
bad weather conditions or limited to a wire, nor do they
leave the gunner vulnerable for attack. GPS guided
weapons are going to be the superior weapons of choice
in modern day warfare with their technological advances
over previous.
Further, as what Dr. Mashelkar told ‘The toughest
thing in the world is to predict about the future’, it will
be too early and incompetent to predict about the
future enhancements and up-gradations that new
technology will bring in a decade or so.