1998 First 25 MHz system test

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Rutgers University Coastal Ocean Observation Lab
Operate New Jersey Shelf Observing System
1) L-Band and X-Band satellite receivers 2)
Nested Multi-static HF radar array 3)
Long-duration fleet of autonomous
underwater gliders
CODAR HF Radar Operations with the New Jersey
Shelf Observing System
1998 - First 25 MHz system test 1999 - 25 MHz
system setup for continuous operation 2000 -
First 5 MHz system deployed - Begin
testing 25 MHz Bistatic Augmentation 2001 -
Operational 5 MHz network with four systems
- Deploy 25 MHz bistatic transmitting buoy
- Begin testing 5 MHz Bistatic
Augmentation 2002 - Implement multistatic/multi-fr
equency network - 2 25 MHz
systems - 4 5 MHz systems 2003 -
Deploy 5 MHz bistatic buoy - Help extend
coverage along entire Northeast coast
as part of NEOS Currently operate 10
systems from Wildwood, New Jersey to
Nantucket, Ma.
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CODAR Ocean Sensors, Ltd.The Leader in HF
Surface-Wave Radar Ocean Monitoring

• Company principals have been continuously
  involved in HFSWR for 35 years
• Patented CODAR Hallmarks
• Compact antenna system --small footprint offers
  unobtrusive coastal presence
• Unmanned, real-time operation
• Low power -- both radiated and required input
  supply
• GPS-synchronized multiple-radar and multi-static
  operation at same frequency
• Currents mapped to 200 km with Long-Range
  backscatter SeaSondes
• Bistatic augmentation by CODAR demonstrates
  coverage extension to 330 km
• Over 150 CODAR SeaSondes manufactured and sold --
  85 of all HFSWRs
• Systems logged over 4 million operating hours to
  date
• Recent "Dual-Use" objectives being pursued to
  examine ship detection/tracking
• Robust, multiple-look at same target defies
  evasion
• HFSWR is CODAR's only product -- provides us
  unparalleled focus of direction

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Applied Mathematics, Inc.
SHIP-TRACKING SAMPLE
SHIP-TRACKING SAMPLE
COMPANY BACKGROUND
COMPANY BACKGROUND

• Extensive experience in development, at sea
  testing, and analysis of ship detection and ship
  tracking algorithms for US Navy and the United
  Kingdom Royal Navy
• Have provided on site technical support for 28
  years in search and ship tracking tactics to
  Commander Submarine Development Squadron TWELVE,
  the tactical development agent for the Submarine
  Force
• Developed over past twenty-five years search and
  tracking computer programs (called tactical
  decision aids) for real time use on board
  submarines
• Developed ocean current data assimilation and
  area of uncertainty tracking algorithms for US
  Coast Guard Search and Rescue applications

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OBJECTIVES

• Test new transmission waveforms
• Multistatic SeaSonde data from the network will
  be collected, however, this initial set of tests
  will focus on analyzing the backscatter data only
• Test different detection algorithms
• Test the sensitivity of the MUSIC direction
  finding algorithm to ideal versus measured beam
  patterns for hard targets
• Define the parameters to optimize dual-use ship
  tracking and current mapping with a Codar
  SeaSonde

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HF RADAR NETWORK
180 km
RUTGERS
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Loveladies, NJ
New Jersey Installations
Brant Beach, NJ
USCG LSU Wildwood, NJ
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5 MHz Loveladies ,NJ
5 MHz Sandy Hook ,NJ
5 MHz Tuckerton, NJ
New Jersey Installations
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Vessel-Tracking Applications
Vessel-Tracking Applications
USCGC Finback
R/V Endeavor
SeaTow 41
M/V Oleander
SeaTow 25
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TEST PARAMETERS

• Transmit Frequency
• Range Cell Size
• Blanking
• Sweep Repetition Rate
• Sea State Monitored

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13 Field Trials to Date
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BLANK PERIOD
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DETECTION ALGORITHM

• Simultaneous Multiple Sliding Window FFTs in
  Doppler Processing
• Two Types of Background Calculation
• Median (average in doppler and range space)
• Infinite Impulse Response (average in time)
• 3D Background (Time, Range and Doppler) Varying
  with Sea Echoes
• Thresholding of Peaks --- Local SNR of Monopole
  or at Least One of the Two Dipoles
  Have to be above the Threshold
• MUSIC Algorithm used to determine Bearing -
  Bearing Resolution Determined by Antenna Pattern
  - Bearing Precision Determined by SNR
  (1/sqrt(SNR))

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Removing HF radar bias in bearing determination

• Environment distorts antenna pattern away
• from ideal
• Measure antenna pattern using vessel
• mounted transponder
• Account for measured distortion in software

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Ship Tracking AlgorithmKalman Filter

• A Kalman Filter provides a recursive solution to
  the least squares problem.
• Assumptions include linear target motion and
  normally distributed measurement errors.
• Tracker inputs are
• time
• radar transmitter and receiver positions
• range, bearing, and range rate and
• range, bearing, and range rate uncertainties.
• Tracker outputs are
• target position
• velocity and
• estimates of position and velocity uncertainties
  (covariance matrix).
• Target Maneuver Test a statistical test is used
  to estimate whether a combination of two straight
  tracks fit the data better than a single straight
  track.

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RESULTS
BIG SHIPS

• Endeavor 185 length
• Oleander 387 length
• CG Finback 82 length

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Proof of Concept
R/V Endeavor
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Optimization Phase
USCG Finback
Sample Spectra
Tracker results
Track keeper not track finder
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Vessel-Tracking Applications Two Sites, One Target
Vessel-Tracking Applications Two Sites, One Target
M/V Oleander
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Ship Track of M/V Oleander
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M/V Oleander Large vessel tracking Multiple
sites vastly improve tracking and localization
accuracy
One Site Tracking Two Site Tracking
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RESULTS
SMALL BOATS

• SeaTow 41 41 length
• SeaTow 25 25 length

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SeaTow 41
Loveladies 5 MHz
13 nm
Tuckerton 5 MHz
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SeaTow 41
Boat Speed 25 knots
x
x


Applied Mathematics, Inc.
TUCKERTON
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SeaTow 25
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SeaTow 25
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FUTURE WORKSystem Performance in Varied
Environments

• Based upon the shown work, optimal settings have
  been set at all long-range sites for multi-static
  dual use operations
• Now focusing on a long term data set , M/V
  Oleander sails New York to Bermuda on a weekly
  basis providing ship tracking opportunities while
  the network continues to provide surface current
  maps to the Coast Guard for Search Rescue
  Demonstrations.

• Multiple Frequencies
• Sandy Hook 5, 13 and 25 MHz
• Multiple Sites
• Sandy Hook
• Loveladies
• Tuckerton
• Wildwood