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Glarkson UNIVERSITY
WALLACE H. COULTER SCHOOL OF ENGINEERING Technology Serving Humanity
MEMORANDUM
Subject: Progress Report ULI: FY12 Q3 Progress Report (4/1/2012-6/30/2012)
This document provides a progress report on the project "Advanced Digital Signal Processing" covering the period of 4/1/2012-6/30/2012.
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William D. Jemison, Professor and Chair, PO Box 5720, Clarkson University, Potsdam, NY 13699-5720 315-268-6509, Fax 315-268-7600, [email protected]
ONR Sponsor: Daniel Tarn ONR Code 333 Telephone: 703-696-4204 E-mail: dariiel.tarTi1@navyjTiii
Advanced Digital Signal Processing for Hybrid Lidar
Navy Lab mentor: Dr. Linda Mullen Address: 22347 Cedar Point Rd, Patuxent River, IVID Telephone: 301-342-2021 E-mail: [email protected]
University advisor: Dr. William Jemison Address: P.O. Box 5720 Potsdam, New York 13699 Telephone: 315-268-6509 E-mail: [email protected] ■.:'■■>>-.■-:.:: • -
Presented to:
Annual ULI program review attendees
June 6, 2012
Presented by.
Mr. Paul Perez
Clarkson University
NAV^^^AIR
tRT8 lUNIVtRSin Outline
tiMtmiH''»<*rir A'.«rf>*f*i r ii^i»-a«t kutUlt*
Background and Objectives Approach and Challenges Light Propagation in Water
Progress • Underwater laser range finder • A New Backscatter Reduction Approach
Summary
File: NAVAIR Brief NAV;i^Ar R
Background and Objectives A*ij|x>ii(i.j«a>-i* ki'ftiiin.k , iir^^tt AWjii*
Background The Navy uses hybrid lidar-radar for
underwater detection, ranging, communications, and imaging. - Modulate the lidar laser light intensity with radar
waveforms
- Recover the radar waveform from the received lidar optical signal
- Use coherent detection and other radar techniques to process the signal.
Objectives
To enhance hybrid lidar-radar performance: - Develop and evaluate various digital signal
processing (DSP) algorithms that will enhance the Hybrid Lidar-Radar performance.
- Implement the algorithms via DSP hardware • dynamically reconfigured via software (accomplish
multiple missions with a single sensor) • real-time processing • reduced loss/temperature sensitivity
us™ AAAA IJDAR
Vliniiiiize Ahsorption RADAR
Coherent Detcaion
jyiAA Hybrid LIDAR-RADAR Technologj'
Radar transmLssum-deleclkm in an smderwater environment
DSP Advantages
Component Availability/Cost Component Sensitivity/Performance
• Adaptability • Real Time Processing • Borrow waveforms/algorithms from
RADAR.
File: NAVAIR Brief NAV/^AI R
Approach and Challenges R ^Wi^tiim^'^ li,ffMt^k ., ■ krifutat Uemkf
Approach - Leverage known radar processing
techniques - Use existing performance prediction
models to generate data for multiple scenarios (system geometry/configuration, water optical properties, etc.)
- Use data to test the performance of DSP algorithms
- Compare results with experimental data - Use COTS DSP, FPGAs, and Software
Defined Radio (SDR) hardware to accelerate development and minimize cost
Principle Problems/Challenges - Many COTS DSP hardware platforms are
suitable for communications but lack performance for detection and ranging
- Radar propagation channel and the lidar propagation channel are very different
^'^t'9 .Water optical properties .""9 .Wateropticalp
Rangefinder - used to generate hybrid lidar-radar signals for DSP algorithm verification
vs.
COTS Software Defined Radio Evaluating performance of two COTS Software Defined Radios (Signal hound vs. COMBLOCK).
File: NAVAIR Brief
Light propagation in water \-4^/
<^1! Scattering
rransmitter ] -^/'^
Receiver -«I^^^^B
Field of view
Sinali-angle fonvard _ scattering Absorption^
^ Scattering Object
Wavelength Selection Absorption vs. Scattering Limited Performance Modulation Frequency
Depth in meters
50
100
150
200
Light penetration - coastal ocean
Light penetration - open ocean
Depth In meters
50
Backscatter Magnihide vs Modulation Frequency
Scatter-limited detection - more light,
more'clutter'
Absorption-limited detection - more light,
more range r-UmnSiKiltWMIIIIHI
Modulation Frequency {MHzj
Absorption decreases total signal level at the receiver Scattering degrades image contrast, resolution, and reduces range accuracy
i.^:2-i::^itiLi:i2:i:i^iS^^^ AW'-.WXV-
File: NAVAIR Brief NAVj^i^AI R
Progress and Activity fytn&aattutt^ AV^wft-i Hfi»nK( *ii,»«;t*
Project Stall: June 1^*2011 Summer 2011 & Fall 2011 (laser rangefinder)
Participated in the ONR NREIP program at NAWCAD Assisted with water tank experiments
Resulted in SPIE publication/poster presentation "Underwater Laser Rangefinder," Proceedings of SPIE, Ocean Sensing and Monitoring, Volume 8372
• Characterized Software Defined Radios
Spring 2012 (backscatter reduction) Became familiar with Navy Rangefinder simulation tool Identified new backscatter reduction technique Preliminary validation of backscatter reduction technique using simulation data from Rangefinder
Summer 2012 (planned) • Participate in the ONR NREIP program at NAWCAD
Thorough evaluation of backscatter reduction technique Validate backscatter reduction technique with laboratory experiments
File: NAVAIR Brief
. c E
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Laser Rangefinder Results Translation stage
object Water tank
f^=20MHz
170 I'Jd 210 23(1 251) 270 2'H] 31(1 330 350
Actual posilion, d (cm)
170 19U 210 2-10 250 270 2')0 310 HO 350
Actual poaiion , J (cm)
jliinilii.iiil!lllii.tillllfliUi
DC bias
488 nm Laser diode
A.W>^ftiu<it«ry J^iOVtUvJi. . . Htd^MU Urntk*
f=L DDS source
PMT
Optical filter
BPF
Jc ~ J m
SDR receiver
J c J m
Multimeter | f\ fX f\ f\
f^= 180MHz
150 170 190 210 230 250 270 290 310 330 350
Actual posilion , t/(cin)
ISO I7li 190 210 230 250 270 2'JO 310 330 350
Actual position . d (cm)
T/R separation = 12.5cm
Receiver FOV = 4 deg
SDR - COM-3011
Data shown presented in SPIE paper: "Underwater Laser Rangefinder," Proceedings of SPIE, Ocean Sensing and Monitoring, Volume 8372
ExperJnnental results show only the mean values to connpare with model predictions
Range error as a function of integration time is reported in the paper
c= 1.6 m-'' File: NAVAIR Brief
A New Backscatter Reduction Approach j,W<>^tiMfury (i^tMI\.k . . . firifi^Ult (Atimiu
Leverage Techniques Developed for Through the Wall Imaging (TTWI) Radar
Antenna Target
Wali
TTWI - unwanted returns from the wall
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Wall return is independent of antenna position Target return phase varies with antenna position
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Spatial lii.A frequency "t\l ii^JU,
filter ,' •:;;;i&
Spatial frequency donnain Enhanced performance
Hybrid Lidar- unwanted returns from backscatter (BSN)
Target
Backscatter is independent of receiver position Target return phase varies with receiver position
/
Spatial frequency
filter 9 Spatial frequency domain
File: NAVAIR Brief
Enhanced performance
N AV^^A I R
Spatial Frequency Filters i^j
There are a variety of spatial filters that have been developed for radar Single delay line, multiple delay lines
• Recursive, feed forward
etc. siH —, -^-^(l) >Sout
Selected single delay line for proof-of-concept • Simple and easy to implement
• Derived the filter response as a function of delay and water attenuation coefficient • Investigated backscatter reduction in high turbidity conditions(2.4m-^) at 100,
$2
500,1000 MHz.
Rangefinder: Generate Simulated
Hybrid-Lidar Data
^
Matlab: Simulate
Spatial Filter
Compare analytical and
simulated filter
response
Completed/In Progress
Planned
Simulate backscatter reduction at
several modulation frequencies
Experimental ^ validation of
backscatter reduction technique
DSP hardware implementation
of candidate filters
File: NAVAIR Brief NAV^^rAI R
F^ Delay Line Filter Transfer Function
Derived delay line filter response:
iV*<>i.(i«M*j> ti,>fMii;li .. - k^Mat AVufe
|G(c,Az)| = Vl + e-2^^^ - 2e-2'^^^co5(fcAz)
Good agreement between analytical and simulated response Magnitude Response of Delay Line Filter
025 Delay Dz (meters)
File: NAVAIR Brief
•• '^'iA 't^x.'jii:^v^x^;v^jiA.'^x.'^'*^xi^fa^v°^%^^ \.\>^ - A>. \\ W
NAV;?^AI R
HSH| Backscatter Reduction Simulation fmod = 100 MHz; Az = 1.13m; c = 2.4m-i A^»A,(Biit«»^ if^^j^fiif,.. a^x^-^uti jtWdi^*
-30dB backscatter reduction; ~3nn improvement in range;
Distance (meters)
File: NAVAIR Brief N fi<\f^^fK I R
Range Performance f^^rf = 100 MHz; Az = 1.13m; c = 2.4m-i
o q> B
o c iS
Q o
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tf)
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Before Filter After Filter Ideal
12 3 4 5 Ideal Object Distance (meters)
File: NAVAIR Brief
Glarkson u Ni vEaniyi Backscatter Reduction Simulation
f„od = 500 MHz; Az = 0.226m; c = 2.4m-i g.,.J,,J^u., )>'.•*«»».,. KA.j.,1 (,'.,.A
~38 dB backscatter reduction; ~4.5 m improvement in range;
~4.5 m
1.5 2,5 3 3.5 Distance (melers)
4Jt 5.5
File: NAVAIR Brief 1; 3 NAVJ?^'AI R
Range Performance f^od = 500 MHz; Az = 0.226m; c = 2.4m-i
(/) o +-• 0)
u c (0
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Q o (D
O
^ 3 U) (0 0)
Before Filter After Filter Ideal
Ideal Object Distance (meters)
File: NAVAIR Brief
Backscatter Reduction Simulation f„„d = 1000 MHz; Az = 0.113m; c = 2.4m-i (,V«ili««.,, R.,M,d .. fci,j»i ««.fc
~38dB backscatter reduction; ~4 m improvement in range;
~ 4 m
0 c •t.O S C.E I G
File: NAVAIR Brief N A Vii^A I R
Range Performance fmnH = 1000 MHz; Az = 0.113m; c = 2.4m
^ r-
a> E
o 4 c re (/)
S3 o
^2 o 3 (A *^ ^ <D -^
0 0
Before Filter After Filter Ideal
1 2 3 4 5 Ideal Object Distance (meters)
File: NAVAIR Brief
Summary A*.«^>^«»M'« AIWH*. i.., kvU-Mtt *.V»t/t»t
Experience gained in summer 2011 internship at NAWCAD:
• Gained background in underwater optics
• Learned basics of RF modulation/demodulation via digital components • Performed initial experiments that led to SPIE publication/poster presentation
Accomplishments during 2011-2012 academic year: • Courses taken/knowledge gained: Signal Processing
• Characterized a commercial SDR and concluded that it is convenient to interface with an SDR to obtain the needed data for ranging calculations.
• Became familiar with Rangefinder simulation tool
• Identified a new backscatter reduction technique that will improve range calculations.
Future plans:
• 2012 Summer internship at NAWCAD - experimental validation of delay line predictions
• Participate in the student poster competition at the 2012 MTS/IEEE Oceans Conference (October, 2012)
• Courses planned: Signal Processing, Software Defined Radio
File: NAVAIR Brief N AV/i^A r R