Research Areas

1
Atmospheric Propagation of High Energy Lasers
Modeling, Simulation, Tracking, and ControlMRI
(AFOSR Grant F49620-02-01-0319)
Adaptive Optics (AO), Jitter Control, Target
Tracking Recent Advances and Transitions

• UCLAs new AO methods have improved laser beam
  control in the Atmospheric Simulation and
  Adaptive-optics Laboratory Testbed at the
  Starfire Optical Range, Kirtland AFB.
• Current collaboration with Rockwell Scientific
  Company and AFRL, Kirtland, will transition
  UCLAs methods for beam control to Rockwells
  new liquid crystal devices (sponsored by JTO)
  for laser beam steering.
• AO methods (UCLA) based on adaptive filtering
  and control have been successful in
  high-fidelity ABL simulations (ATK/Mission
  Research) with active illumination and
  tracking.
• Bayesian Tracker (Georgia Tech, Tempest
  Technologies) and the new AO methods (UCLA)
  combined have produced 77 increase in HEL
  intensity on target in high-fidelity
  evaluations (ATK/ Mission Research).
• Efforts are underway to integrate UCLAs new
  jitter control algorithms into a jitter
  control laboratory being developed at AFRL,
  Kirtland AFB.

Research Areas

• Modeling and Simulation of Beam Propagation
  Extended Turbulence Active Illumination
  Thermal Blooming
• New Methods for Wave Front and Jitter Control
  Adaptive Filtering and Control
  Novel Wave Front Sensing
• Imaging and Tracking through Turbulence
  Image Processing Adaptive Prediction

UCLA Steve Gibson, Tsu-Chin Tsao Michigan Tech
Mike Roggemann, Tim Schulz Georgia Tech Allen
Tannenbaum MZA Associates Corp Eric Magee,
Matthew Whiteley Tempest Technologies Ben
Fitzpatrick, Yun Wang Trex Enterprises Mikhail
Belenkii
2
Atmospheric Propagation of High Energy Lasers
Modeling, Simulation, Tracking, and ControlMRI
(AFOSR Grant F49620-02-01-0319)
PI
Steve Gibson, UCLA

• Transitions
• UCLAs adaptive control and filtering methods
  for adaptive optics have been implemented to
  improve beam control in the Atmospheric
  Simulation and Adaptive-optics Laboratory Testbed
  (ASALT) at the Starfire Optical Range at the
  Air Force Research Laboratory, Kirtland AFB.
  This is a collaboration with Dr. Troy A.
  Rhoadarmer and Lt. Laura M. Klein of AFRL. It
  has produced one paper (SPIE conference,
  August 2006), and more are planned.
• UCLA is collaborating with Teledyne Scientific
  Company and AFRL, Kirtland AFB, to apply adaptive
  jitter control algorithms with Rockwells
  prototype liquid crystal devices for steering
  laser beams. This is a collaboration
  with Dr. Dan Herrick of AFRL and Mr. Bruce Winker
  of Rockwell Scientific Company. Teledyne is
  funded by HEL JTO.
• Efforts are underway to integrate UCLAs new
  jitter control algorithms into a jitter control
  laboratory being developed at AFRL,
  Kirtland AFB, under the direction of Dr. Dan
  Herrick.
• UCLAs adaptive jitter control methods are
  being used in a relay-optics experiment at AFRL
  under an SBIR to Tempest Technologies, funded
  by MDA.
• UCLAs methods for adaptive control in adaptive
  optics are being used in an SBIR to MZA
  Associates Corporation for mitigation of
  aero-optics effects in directed energy weapons,
  funded by MDA.

3
REFERENCES Yu-Tai Liu and Steve Gibson,
Adaptive Control in Adaptive Optics for Directed
Energy Systems, Optical Engineering, to
appear. Troy A. Rhoadarmer, Laura M. Klein,
Steve Gibson, Neil Chen and Yu-Tai Liu, Adaptive
Control and Filtering for Closed-loop
Adaptive-optical Wavefront Reconstruction, SPIE
Conference on Advanced Wavefront Control, San
Diego, CA, August 2006. Nestor O. Perez
Arancibia, Neil Chen, Steve Gibson and Tsu-Chin
Tsao, Variable-order Adaptive Control of a MEMS
Steering Mirror for Suppression of Laser Beam
Jitter, Optical Engineering, November
2006. Nestor Perez, Neil Chen, Steve Gibson and
Tsu-Chin Tsao, Adaptive Control of Jitter in
Laser Beam Pointing and Tracking, SPIE
Conference, San Diego, CA, August 2006. Pawel
Orzechowski, Neil Chen, Steve Gibson, and
Tsu-Chin Tsao, Adaptive Control of Jitter in a
Laser Beam Pointing System, American Control
Conference, 2006. Pawel K. Orzechowski, James S.
Gibson, and Tsu-Chin Tsao, Optimal Suppression
of Laser Beam Jitter by High-order RLS adaptive
control, IEEE Transactions on Control Systems
Technology, to appear. Nestor Perez, Steve
Gibson, and Tsu-Chin Tsao, Adaptive Control of
MEMS Mirrors for Beam Steering, IMECE2004
(ASME), November 2004. Yu-Tai Liu, Neil Chen,
and Steve Gibson, Adaptive Filtering and Control
for Wavefront Reconstruction and Jitter Control
in Adaptive Optics, American Control Conference,
2005. Nestor Perez, Neil Chen, Steve Gibson,
and Tsu-Chin Tsao, Adaptive Control of a MEMS
Steering Mirror for Suppression of Laser Beam
Jitter, American Control Conference,
2005. Nestor O. Perez Arancibia, Neil Chen,
Steve Gibson and Tsu-Chin Tsao, Adaptive
Control of a MEMS Steering Mirror for Free-space
Laser Communications, Optics and Photonics 2005
(SPIE), San Diego, CA, August 2005.
4
ABL SimulationStrong Turbulence and Platform
Jitter
SIMULINK BLOCK DIAGRAM
WaveTrain ABL Model
Standard AO Loop
WaveTrain ABL Model
Adaptive Filtering and Control
HEL Energy Distribution on Target
Time-Averaged Energy Distribution (Normalized)
Standard AO Adaptive
Control
5
Atmospheric Propagation of High Energy Lasers
Modeling, Simulation, Tracking, and ControlMRI
(AFOSR Grant F49620-02-01-0319) PI Steve Gibson,
UCLA
Adaptive Control of Laser Beam Jitter Jitter
caused by platform vibration and atmospheric
turbulence presents serious problems in Laser
Weapons (ABL) and Laser Communications. New
adaptive control methods significantly extend
bandwidth of existing feedback track loops.

• New variable-order adaptive control
• fast adaptation
• optimal steady-state performance
• eliminates large transients.

UCLA Beam-Steering Experiment
LaserSource
FSM 1
FSM 2
Sensor
Control actuator Fast steering mirror FSM 1
mounted on shaker Three jitter sources Shaker,
table vibration, FSM 2
RLS lattice filter generates adaptive control
commands un for all orders n 1, 2, , N.
Adaptive loop closed at 10 sec.
6
Liquid Crystal Devices for Control of Laser Beams
Pawel K. Orzechowski, Steve Gibson, Tsu-Chin Tsao

• UCLA, AFRL and Teledyne Scientific Co. have
  collaborated to apply feedback and adaptive
  feedforward control to Teledynes new liquid
  crystal beam steering devices.
• LC beam steering devices have attractive
  properties for laser applications No moving
  parts, Low power
• But significant questions must be answered about
  LC devices in high-performance beam control.
• This research combines new hardware and new
  control methods.

UCLA Beam Steering Experiment
Teledyne Liquid Crystal Device
Dan Herrick, Pawel K. Orzechowski, Steve Gibson,
Tsu-Chin Tsao, Milind Mahajan, and Bing Wen, An
alternative beam alignment approach for tactical
systems, Directed Energy Systems Symposium Beam
Control Conference. Monterey, CA DEPS, March
2007. Pawel K. Orzechowski, Steve Gibson and
Tsu-Chin Tsao, Dan Herrick, Milind Mahajan, and
Bing Wen, Adaptive suppression of optical jitter
with a new liquid crystal beam steering device,
SPIE Defense and Security Symposium. Orlando,
Florida, April 2007. Herrick (AFRL, Kirtland
AFB) Mahajan and Wen (Teledyne Scientific Co.)
Orzechowski, Gibson and Tsao (UCLA)
7
Adaptive Control of Laser Beams for Laser Weapons
and Communications
UCLA Beam Steering Experiment
Teledyne Liquid Crystal Device

• Two important questions
• Can the new liquid crystal devices steer laser
  beams effectively at hundreds of Hz?
• Can UCLAs adaptive control methods compensate
  for unmodeled nonlinearities in the new devices?

• Initial answers from UCLA experiments
• Yes
• Yes
• Results at right show adaptive control of
  jitter in multiple bandwidths, including jitter
  at 350Hz.
• Adaptive control loop closed at t 19 sec.

8
Adaptive Control and Filtering for Closed-loop
Adaptive-optical Wavefront Reconstruction
Advanced Wavefront Control SPIE Annual Meeting 14
August 2006
Troy A. Rhoadarmer and Laura M. Klein Optics
Division, Directed Energy Directorate, U.S. Air
Force Research Laboratory, Kirtland AFB, NM
87117-5776 USA Steve Gibson, Neil Chen, and
Yu-Tai Liu Mechanical and Aerospace
Engineering University of California, Los
Angeles, CA 90095-1597 USA
AFRL research sponsored by AFOSR Laboratory Task
LRIR-93DE01COR. UCLA research sponsored by HEL
JTO and AFOSR, AFOSR Grants F49620-02-01-0319 and
F-49620-03-1-0234.
9
Adaptive Controller for AO
y measured wavefront c DM command vector E0
and E1 map WFS data to DM modesV maps modal
commands to actuatorsLoop delay d 1 frame
FIR filter L(z) predicts wavefront to compensate
for loop latency and limited bandwidth of
classical AO loop.

• Two Types of Implementation
• Fully adaptive filter gains updated at each
  frame
• Quasi-adaptive piece-wise constant filter gains
  identified and
  updated periodically from wavefront sensor data

10
ASALT Lab

• AO Test Evaluation Laboratory

Atmospheric Turbulence Simulator
577-channel Deformable Mirror25 actuators across
pupil
Well-controlled calibrated and
reproducible test conditions
Indigo Phoenix cameras
Flexible test over a wide range of
operational scenarios
49x49 SRI-WFS
11
Experimental Results

• Frame-by-frame Peak Strehls

12
Example Scoring Camera Images
Classical Control, 150 modes
Quasi-Adaptive Control, 150 modes
Classical Control, all modes
13
Closed-Loop Centroid Jitter
Time Series
Classical AO, 150 modesStandard deviation
(x,y) (1.2335, 0.8791)
Adaptive Control, 150 modesStandard deviation
(x,y) (0.7522, 0.5139)
Classical AO, all modesStandard deviation
(x,y) (1.1553, 0.7905)
Centroid Scatter
Units pixels on scoring camera In each graph
top curve x-axis jitter
bottom curve y-axis jitter
14
Conclusions from ASALT

• Collaboration between AFRL and UCLA under AFOSR
  and HEL JTO funding.
• New adaptive control algorithms for AO enhance
  beam control and imaging through turbulence.
• The algorithms have been tested recently in AO
  experiments in the ASALT Lab at the Starfire
  Optical Range (AFRL) at Kirtland AFB.
• In initial experiments, the quasi-adaptive
  version of these algorithms yielded higher
  resolution and tighter concentration of energy
  with approximately 50 increase in peak Strehl
  ratio.
• In upcoming experiments, the fully-adaptive
  version of the control algorithm is expected to
  improve performance further.

15
Liquid Crystal Devices for Beam
ControlUCLA/Rockwell Scientific Collaboration

• Collaborators
• Steve Gibson, T.-C. Tsao, Pawel Orzechowski
  (UCLA)
• Dan Herrick (AFRL, Kirtland AFB)
• Bruce Winker, Milind Mahajan and Bing Wen
  (Rockwell Scientific Company, now Teledyne
  Scientific, funded by HEL JTO. )
• Objectives
• Apply adaptive jitter control algorithms with
  Rockwells prototype liquid crystal devices
  for steering laser beams in directed energy
  systems
• System identification of liquid crystal beam
  steering devices
• Modeling for control

16
REFERENCES Yu-Tai Liu and Steve Gibson,
Adaptive Control in Adaptive Optics for Directed
Energy Systems, Optical Engineering, to
appear. Troy A. Rhoadarmer, Laura M. Klein,
Steve Gibson, Neil Chen and Yu-Tai Liu, Adaptive
Control and Filtering for Closed-loop
Adaptive-optical Wavefront Reconstruction, SPIE
Conference on Advanced Wavefront Control, San
Diego, CA, August 2006. Nestor O. Perez
Arancibia, Neil Chen, Steve Gibson and Tsu-Chin
Tsao, Variable-order Adaptive Control of a MEMS
Steering Mirror for Suppression of Laser Beam
Jitter, Optical Engineering, November
2006. Nestor Perez, Neil Chen, Steve Gibson and
Tsu-Chin Tsao, Adaptive Control of Jitter in
Laser Beam Pointing and Tracking, SPIE
Conference, San Diego, CA, August 2006. Pawel
Orzechowski, Neil Chen, Steve Gibson, and
Tsu-Chin Tsao, Adaptive Control of Jitter in a
Laser Beam Pointing System, American Control
Conference, 2006. Pawel K. Orzechowski, James S.
Gibson, and Tsu-Chin Tsao, Optimal Suppression
of Laser Beam Jitter by High-order RLS adaptive
control, IEEE Transactions on Control Systems
Technology, submitted. Nestor Perez, Steve
Gibson, and Tsu-Chin Tsao, Adaptive Control of
MEMS Mirrors for Beam Steering, IMECE2004
(ASME), November 2004. Yu-Tai Liu, Neil Chen,
and Steve Gibson, Adaptive Filtering and Control
for Wavefront Reconstruction and Jitter Control
in Adaptive Optics, American Control Conference,
2005. Nestor Perez, Neil Chen, Steve Gibson,
and Tsu-Chin Tsao, Adaptive Control of a MEMS
Steering Mirror for Suppression of Laser Beam
Jitter, American Control Conference,
2005. Nestor O. Perez Arancibia, Neil Chen,
Steve Gibson and Tsu-Chin Tsao, Adaptive
Control of a MEMS Steering Mirror for Free-space
Laser Communications, Optics and Photonics 2005
(SPIE), San Diego, CA, August 2005.