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Today’s Surveillance Issue
Surveillance systems must be capable of measuring unknown or unfriendly transmissions and possibly extract the target information content.
Direction Finding (DF) and geolocation are usually associated with these types of systems as signal recovery and knowledge of the emitter location is desirable.
Surveillance of wireless signals is rapidly expanding in the areas of spectrum regulation, public safety, boarder and coastal security and military intelligence.
In the government and military areas, these transmissions are often characterized in a category called Signals Intelligence (SIGINT).
Who needs Signal Monitoring?
Typical Users:
International Defense Agencies
International Government End-users and Contractors
Military and Commercial Test Range and “Frequency Managers”
Prime Contractors involved in RF Range tests International
Worldwide Aerospace Service providers
Regulatory Agencies (similar to FCC in US)
Commercial Spectrum Monitoring
Commercial Manufacturers of Communications Systems
Measurement Needs
Make “off-the-air” measurements Hunt RF interference in a crowded spectrum Detecting small signals in a large band Ultimately need to “control” the RF airspace May need to “shut down” illegal transmitters May need to clear the test range of emitters before a test May need to get a “baseline” on the environment Need a complete solution for high performance RF survey
RF Spectral Monitoring Challenge
Signals of interest are not in your control – Signals of interest can be at any frequency– They may be short duration – Signals of interest are intermittent– They may be low power
RF environment is not in your control– There may be thousands of irrelevant signals of varying
power, duration, and bandwidth
RF Spectral Monitoring Challenge
Maximize Probability of Intercept (POI)
POI - The probability that a search system will detect the presence of a signal of interest.
Advanced RF Spectral Monitoring Solution Signals of interest are not in your control
– Signals of interest can be at any frequency
– They may be short duration – Signals of interest are intermittent– They may be low power
RF environment is not in your control– There may be thousands of irrelevant
signals of varying power, duration, and bandwidth
Wide Bandwidth
High Speed SearchHigh Resolution
Signal Detection Tools
RF Spectral Monitoring – What You Need
• You need high speed RF search– Signals may come and go– Wide spectrum to search
Page 9
Problem:Swept Spectrum
Analyzers only provide speed OR resolution
E3238S = Speed AND Resolution
AND• You need high resolution
– Signals may be near other signals– Signals may be near noise
Basic System Components
Page 10
E2730B tuner (2.7 GHz) or
E2731B tuner (6.0 GHz)
E1439D ADC
E9821A Signal Processor
IEEE-1394 (Firewire) connects PC to
E8491B VXI Slot 0
System Architecture
Page 12
Tuner Digitizer Spectrum computation Processing
Short tuner settling time allows fast
frequency steps.
Wide IF bandwidth (high sample rate) reduces the
number of steps.High dynamic range to
accurately digitize multiple signals.
High speed digital I/O to transfer the data at real-time rates.
Multiple Digital Signal Processors (DSP) working in
parallel to compute the spectrum.
Additional processing preserves the high resolution (maybe
500,000 points!), and finds signals of interest.
RF Sweep Speed vs. Resolution (E3238S)
Page 13
0.01
0.1
1.
10.
100.
0.11.10.100.1,000.
Resolution (RBW kHz)
Swee
p Sp
eed
(GHz
/Sec
)
4 GHz/SecOr 250 mSec/GHz
E3238S isover 1000 times
faster!Example:1GHz Span2 kHz RBW
(500,000 points!) 5 Minutes
Page 15
What is a search and collection system?
Search
Rapid hunt for energy/signals
Sort for energy & signals of interest
Operator judgementAutomated software
algorithmsAutomated detectors
Monitor
Collect/exploit signals of interest
Handoff RxTape/disk recorderModulation analyzersLocate/trackDDC+DSP
Classify
Page 16
E3238S Signal Detection Tools
High Resolution and High
Speed Spectrum
Energy History
Alarm Conditions
Energy Detection Threshold
Alarm TasksHandoff
Snapshot
Freq. List
…
Signal Detection Tools are needed to reduce the data to information – just the “signals of interest”
Page 17
Requirements
The RF Spectrum
Detect new RF spectral energy
Is energy of interest?
Detect & demod/decode
signal
Is signal of
interest?
SOI Payload
Wideband search
Narrowband collection
Computational complexity
Universal Signal Detector
Page 18
• Bandwidth• Frequencies, or frequency bands
• Shape of power spectrum• RBW• Averaging
• Modulation Recognition • Format, Symbol rate, bandwidth, deviation, …
• Automatic, simultaneous, gap-free recording of signal of interest (raw IQ, AM, or FM)
Exploits characteristics of an RF transmission that can be used to automatically identify signals of interest
Narrowband ConfirmerNarrowband Confirmer
Wideband DetectorWideband Detector
Universal SignalDetector
Bandwidth Filter,Frequency Plan
Wideband Detectors
Narrowband Confirmers
Recording or Streaming
Detectors employ both wide and narrowband technologies to maximize POI
Page 20
Automating the wideband search process
Does RF energy exceed spectral threshold?
Do energy features meet pre-defined alarm criteria?
Extract energy features and put in database
Execute pre-defined energy alarm tasks
yesno
yesno
Handoff receiver(s)
Audio alarm
Visual alarm
Is energy of interest?
Process is based on externalenergy info
•Center frequency
•Bandwidth
•+ others ( shape)
Pass C
F and span to narrow
band collection process
CF, BW, etc
Page 21
Automating the narrowband collection process
Extract signal info and put in database
Detect, demod, and decode signal
Execute pre-defined signal alarm tasks
yesno
Audio alarm
Visual alarm
Is signal of interest?
Process is based on internalsignal info
•Mod type
•ASCII message
•Baud rate
Execute another narrow
band collection process
Does signal info meet pre-defined criteria?
Mod type, ASCII message, etc
Page 22
Noise threshold
Environment threshold
Auto (noise-riding) threshold
Level threshold
Energy Detection Thresholds
Page 24
Others tools to detect /exploit (Universal Signal Detection and Multi-Channel Continuous Recording)
Not only detect signals based on their energy but Detect signals of interest based on their characteristics…
• Frequency• Bandwidth• Spectral shape• Modulation type• Symbol rate
… and record them for analysis(or stream them for in-line processing)
Page 25
Narrowband Confirmation
HF ALECriteria
Confirm the Signal of Interest with narrowband modulation recognition
Modulation Types Confirmed
Page 26
– 16 QAM– 32 QAM– 64 QAM– 128 QAM– 256 QAM– AM– AM DSBSC– LSB– USB– OOK (aka ASK)
– FM OOK– 4PAM (aka 4-level ASK)
– Manual Morse– Machine Morse
– FSK– 3-level FSK– 4-level FSK– 8-level FSK– Analog FM (includes multi-
level FSK not shown above)
– MSK (includes GMSK andOffset (aka Staggered) QPSK)
– FM MSK– BPSK– QPSK (includes DQPSK)
– /4 QPSK (incl. /4 DQPSK)
– 8 PSK– 16 PSK– V.29 Modem
– Pure Carrier– Noise– Unknown Digital
(reports symbol rate of other digital modulation formats)
Modulation Attributes
– Frequency– Bandwidth– SNR– Symbol Rate– Frequency Deviation
E3238S SQL Database
The E3238S system has an integrated SQLrelational database
– Relates Energy History and Signal Database
– Adds antenna, receiver location, and direction to Energy History
– Adds periodic updates of amplitude, location, and direction to Energy History
– Stores data from multiple instances of E3238S using one license
– Query DB directly with SQL or use E3238S commands through the command socket
– User selectable storage duration with automatic clean-up
– No additional cost– PostgreSQL
Page 27
E3238S
E3238SE3238S
E3238S
PC
Handoff Receiver Drivers
Page 28
WJ-8607WJ-8611WJ-8615PWJ-8621WJ-8629WJ-8629AWJ-8634WJ-8711WJ-8712AWJ-8712PWJ-8721WJ-8723WR-G303e
Aro AR5000ACubic VXI-3250Cubic VXI-3550Cubic VXI-3570Cubic R-2411/UCubic R-2412/UIcom IC-R20Icom IC-R8500Icom IC-PCR1000R&S EK-895Ten Tec RX-331
Drivers for other handoff receivers may be developed with Host User Programming (option ASD) or contact factory AE’s
E3238S Option WRP - Features
Delivers continuous, gap-free, full IF record/playback
Can be added to both HF and V/UHF E3238S Signal Detection and Monitoring Systems
Monitor the RF spectrum in a continuous loop recording mode
Record now, analyze later
Playback data into the E3238S DSP taking advantage of all detection and narrowband collection functions
Playback data at different rate to change POI vs. processing time tradeoff
Page 29
Integration with TCI Wideband DF Processor
Page 30
• Simultaneous DF on all detected signals• Configurations for Fixed-Site, Temporary,
and Mobile• V/UHF 20MHz – 3GHz frequency coverage• 20MHz instantaneous bandwidth• 3GHz per sec DF scan rate
Wideband Direction Finding (WDF)
High Speed integrated search, collection and wideband DF
Equivalent to thousands of simultaneous parallel narrowband DF systems
Allows search and collection processes to be qualified by direction-of-interest and LOB.
DF caching allows E3238S collection system to go back in time and precisely re-compute direction on short-duration signals of interest
Intuitive new displays show signal directions by azimuth, color, or tactical polar display
Integrated mapping facility plots emitter LOB on GeoTIFF maps
Industry standard KML output provides tactical DF overlays for popular geographic information system (GIS)
Supported DF systems:1. Now: Variety of Wideband DF subsystems from TCI International, Inc. provide
solutions for mobile, fixed-site and temporary site applications2. Other systems may be supported in future.
Page 31
Seminar Summary
Off-the-air spectral monitoring presents challenges with unknown, non-collaborative, short-duration emitters
High speed AND high resolution are required for measurement of closely spaced, transient, and/or weak signals over a wide RF span
High-speed spectral survey creates enormous amounts of data that signal detection tools must reduce to information – just the “signals of interest”
Multiple simultaneous channels of data can be recorded in a narrowband mode
A commercially-available high-speed survey system from Agilent is optimized for wideband signal survey and narrowband collection