space sec session 5 sreehari rao
TRANSCRIPT
Space Based Signal Intelligence Systems : Global Trends & Technologies
Dr. R. Sreehari Rao
Director
Defence Electronics Research Laboratory Hyderabad
Space Based Signal Intelligence Systems : Global Trends & Technologies
• Need for Satellite based SIGINT
• Types of space surveillance & reconnaissance systems
• Global Trends in SIGINT systems
• Salient features of satellite SIGINT payloads
• Critical SIGINT payload technologies
• Conclusion
NEED FOR SATELLITE BASED SIGINT
LIMITATIONS OF CONVENTIONAL SYSTEMS
• RADIO HORIZON
• PRONE TO MISSILE HITS
• STRAINING OF DIPLOMATIC RELATIONS
SATELLITE SIGINT PLAYED CRUCIAL ROLE IN RECENT
WARS
SPACE SURVEILLANCE AND RECONNAISSANCE
PHOTO RECONNAISSANCE SYSTEMSEARLY WARNING SYSTEMSSIGNAL INTELLIGENCE SYSTEMS
ELINT• RADINT• TELINT
COMINTOCCEAN SURVEILLANCE SYSTEMSIMINTMASINT
MISSIONS OF SPACE BASED SIGINTCOMINT
INTERCEPTION AND DECRYPTION OF MILITARY AND
STRATEGIC COMMUNICATIONS
MONITORING OF TERRORIST ACTIVITIES
ELINT
INTERCEPTION OF RADAR SIGNALS
TELINT
RECEPTION OF TELEMETRY SIGNALS DURING
BALLISTIC MISSILE TESTS
ELINTELINT INVOLVES ACTIONS TAKEN TO
• Search• Intercept • Locate • Record• Analysis of radiated EM energy
ELINT Rxs measure• Angle of Arrival (AOA) • Pulse Width • Pulse Repetion Frequency• Frequency• Time of Arrival• Scan Rate• Location fixing of emitter
COMINT
• Search, DF and intercept
• Location fixing of emitters
• Signal analysis and classification
• Monitoring
• Recording
• Evaluation and comparison with stored data
• Generation of tactical reports
Radar scenario
• Wide Spectral Coverage ( 0.5 – 40 GHz )
• Complex Waveforms
• Wide PRF Range with Jitter and Stagger – 50 Hz to 500 KHz
• Wide Pulse Width Ranges – 50 ns to 500 µs
• Variety of Antenna Scans
• Short Dwell Times
Communication Signal Scenario
• Wide Spectral Coverage ( 1.5 MHz – 18 GHz )
• Complex Waveforms (Burst, FH, DS)
• Non-Standard Data Formats
• High Signal Density
• Low SNR Conditions
• Both NB and WB Signals (FDM & TDM)
• Encrypted Signals
• Short Dwell Times
Handling emerging RF threats ?
To be complemented
Military Satellites Launched in 2006
Ref: SPACESECURITY.ORG 2006
Type of satellites for SIGINT payloads
Group name Weight
Large Satellite >1000Kg
Medium Sized Satellite
500 - 1000Kg
Mini Satellite 100-500Kg
Micro Satellite 10-100Kg
Nano Satellite 1-10Kg
Military SIGINT satellites : Global scenario
ELINT SATELLITES
GRAB (US) CERISE ( FRANCE)
US-P (Soviet )
Mission:
• Monitoring of microwave traffic
• Missile telemetry and data links
• Scud launch detection
Huge unfurlable reflector, large array of feeds to intercept
signals from different locations, to pick up signals from
radios of wrist watch size
GEOWeight : 2700 kg Antenna: 255 ft dia.
SIGINT SATELLITE (US)
Technologies
EORSAT – (Elint Ocean Reconnaissance Satellite – `Cosmos series` - Russia)
• Passive collection of transmissions
from both radio and radar units
• EORSAT constellation consists of multiple satellites in two orbital planes
• Capable of estimating naval positions to within two kilometers
Cosmos
Shenzhou ELINT
Shenzhou – (China)• UHF (300 – 1000 MHz) by three
earth-pointing antennae
deployed on long Telescoping
booms
• Seven horn antennae arranged
in an arc to detect and localize
radar transmissions
MEO
SIGINT SATELLITES• GEO – SIGINT is required for the acquisition
of continuous Signal Intelligence about the
RF threats at specific regions of interest.
• LEO – SIGINT with a group of satellites with inter communication could be a better option for periodic surveillance in the fixed regions of interest.
Typical ELINT system Architecture
Receiver PreprocessorH/W
Main processorH/W + S/W
+ IntelligenceMMI
Extract pulse parameters –Radio frequencyTime of arrivalPulse widthAngle of arrivalAmplitude
Functionality –Pulse de-interleavingPRI analysisFrequency analysisScan pattern analysis Emitter identification
Antennas
Typical ELINT Receiver sensitivity requirements
Satelliteorbit
L-bandAir search radar
ERP = 125 dBmRxg. Antenna gain (- 4 dB)
X-bandFire control
radarERP = 110 dBmRxg. Antenna gain (0 dB)
Ku-band Fire control
radarERP = 100 dBmRxg. Antenna gain (3 dB)
LEO(600 KM) - 70 dBm - 100 dBm - 110 dBm
MEO(10000 KM) - 100 dBm - 120 dBm - 135 dBm
GEO(36000 KM) - 110 dBm - 135 dBm - 145 dBm
DIRECTION FINDING TECHNIQUES FOR SATELLITE BASED ELINT
• Amplitude comparison DF Technique
• Phase comparison Interferometric DF Technique
• Time Difference Of Arrival (TDOA) DF Technique
Amplitude comparison DF Technique
PROCESSOR
45o
Beam Width = Beam Width = 360360No.of AntennaNo.of Antenna
CRYDET
LOGVID
CRYDET
LOGVID
-+AOAAOA
DIFF AMPDIFF AMP
PHASE COMPARISON DF TECHNIQUE
θ
ψ
dθ
λθπψ sin2 d
=
Time Difference of Arrival DF Technique
cos θdc=t
t
θ
d
Satellite SIGINT considerations:
• SIGINT systems on conventional platforms can be reconfigured to space payloads with space qualified components.
• A group of Micro-satellites in LEO are required to cover aspecified region. Microsatellites have the advantagesof light weight, less power consumption, low cost, missionspecific pay load configuration, distributed processing,Launch on Demand etc.
• Location fixing of the target is achieved by employingtriangulation.
• In GEO orbits huge inflatable antennas with MDF techniques can be employed for the emitter location
Technology thrust areas
* Reconfigurable, inflatable and shared apertures
* High sensitivity receivers
* Laser communication systems* Jam resistant secured data links
* Advanced signal processing techniques
* MEMS based components
* Satellite launchers
Critical Technologies
• Multi chip modules • MEOMS• On-board computing & data handling• Neural processing chips• Smart structures• Packaging & Thermal issues • Space qualification
• Excellent sensitivity and selectivity• 100% probability of interception• Capability to handle multiple simultaneous signals
• LTCC,SAW technologies and multilayer structures used ro reduce weight
Channelised receiver
Digital receiver• Simultaneous signal handling capability
• High sensitivity• Simplified RF • Enhanced parameter measurement accuracy
INFLATABLES
Array Fed Reflector Concept Using Inflatable Technologies
Inflatable Microstrip Antenna array
WB Beam Switching Antenna using RF MEMS switches
SubstrateSubstratePatch antennaPatch antenna
Main BeamMain Beam
• MEMS in antenna configuration
• Electronic scanning of the beam
• Light weight & compact size
Shared Aperture Array
• Multi fns from the same aperture
• Electronic switching
• Engineering & packaging is very critical
Frequency Up & Down Converters
• Frequency Translation for Digital Processing Applications
• SAW filtering technology
• Extensive use in IFM & DF systems
On board Processors
• ASIC/FPGA based Digital Processors
• Pulse De-interleaving with neural
network based algorithms
• DF ambiguity resolving algorithms
HTS microwave technology• Inherent low thermal noise in cryogenically cooled Components
• Very high quality factors(>109 ) forresonant structures
• Very high sensitivity
• Rugged, cost competitive Thick-film substrate
• Passive components can be buried between the LTCC tape layers, minimizing lead lengths, improving integration and robustness.
LTCC Technology
Multifunctional Structures
• Each layer of Multifunctional network performs a specificelectronic function like power, ground control, data tx
• Electronic components mounted directly on spacecraft structure without use of PCBs result in weight saving
• Cabling & interconnects are replaced by Multilayer Copper/ Polyimide film
Micro-sat cluster• Formation of Satellites that cooperate to perform thefunction of larger, single satellite
• Smaller satellites communicate with each other, shares the processing, communications & payload or mission functions
•Cluster can be configured for Radar,communications, SIGINT, Geo-location etc.
Distributed Processing
• Optimal Data transfer & parallel processing strategies are used to maximise efficiency
• On-board control algorithms are being developedto reduce ground control requirements
• Data processing from a group of Micro-satellites requiresknowledge of relative positions
Inter satellite Laser Communication
Conclusion
• Satellite based SIGINT systems play a vital role in intelligence gathering for assessing EOB
• These systems complement similar systems employed on the conventional platforms
• The technologies like MEMS, inflatables and MMICs for satellite SIGINT payloads play a critical role
THANK YOU