1. OAWL IIP Development Status: Year 2.0 C.J. Grund, S. Tucker, J. Howell, M. Ostaszewski, and R. Pierce, Ball Aerospace & Technologies Corp. (BATC), cgrund@ball.com 1600 Commerce St. Boulder, CO 80303 Working Group on Space-based Lidar Winds Bar Harbor, ME August 24, 2010 Agility to Innovate, Strength to Deliver Ball Aerospace & Technologies Corp.

2. Page_2 Ball Aerospace & Technologies Acknowledgements The OAWL Development Team: Sara Tucker – Technical Manager, Signal Processing, Algorithms Bill Good (Jim Howell) – Systems Engineer, Aircraft specialist Tom Delker, Bob Pierce – Optical engineering Miro Ostaszewski – Mechanical Engineering Mike Atkins (Kelly Kanizay) – Electronics Engineering Dan Ringoen - (Rick Battistelli), (Dina Demara) – Software Engineering Mike Lieber – Integrated system modeling Paul Kaptchen – Technician Chris Grund – PI, system architecture, science/systems/algorithm guidance OAWL Lidar system development and flight demo supported by NASA ESTO IIP grant: IIP-07-0054 Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration.

3. Page_3 Ball Aerospace & Technologies Aerosol Winds  Lower atmosphere profile Addressing the Decadal Survey 3D-Winds Mission with An Efficient Single-laser All Direct Detection Solution Integrated Direct Detection (IDD) wind lidar approach:  Etalon (double-edge) uses the molecular component, but largely reflects the aerosol.  OAWL measures the aerosol Doppler shift with high precision; etalon removes molecular backscatter reducing shot noise  OAWL HSRL retrieval determines residual aerosol/molecular mixing ratio in etalon receiver, improving molecular precision  Result: ─ single-laser transmitter, single wavelength system, telescope driven by DD requirements not coherent detection ─ single simple, low power and mass signal processor ─ full atmospheric profile using aerosol and molecular backscatter signals Ball Aerospace patents pending Telescope UV Laser Combined Signal Processing HSRL  Aer/mol mixing ratio OAWL Aerosol Receiver Etalon Molecular Receiver Molecular Winds  Upper atmosphere profile 1011101100 Full Atmospheric Profile Data

4. Page_4 Ball Aerospace & Technologies Velocity precision (m/s) Altitude Coherent DWL Etalon DD DWL 1 2 3 0 5km 10 15 20 IDD = OAWL+Etalon Hybrid = Coherent+Etalon Potential Performance Envelope Note: notional approximation etalon+coherent hybrid approach

5. Page_5 Ball Aerospace & Technologies Purpose for OAWL Development and Demonstration  OAWL is a potential enabler for reducing mission cost and schedule ─Aerosol wind precision similar to 2-  m coherent Doppler, but requires no additional laser ─Accuracy not sensitive to aerosol/molecular backscatter mixing ratio ─Tolerance to wavefront error allows simpler (and heritage) telescope and optics ─Compatible with single wavelength holographic scanner allowing adaptive targeting ─Wide potential field of view allows relaxed tolerance alignments, similar to CALIPSO ─FOV ~120 mR feasible while supporting 10 9 spectral resolution ─Minimal laser frequency stability requirements ─LOS spacecraft velocity correction without needing active laser tuning  Opens up multiple mission possibilities including multi- HSRL, DIAL compatibility  Challenges met by Ball OAWL approach ─ Elimination of control loops while achieving 10 9 spectral resolution ─ Thermally and mechanically stable, meter-class OPD, compact interferometer ─ High optical efficiency (~97%) ─ Simultaneous high spectral resolution and large area*solid angle acceptance providing practical system operational tolerances with large collection optics

6. Page_6 Ball Aerospace & Technologies Optical Autocovariance Wind Lidar (OAWL) Development Program  Internal investment to develop the OAWL theory and implementable flight-path architecture and processes, performance model, perform proof of concept experiments, and design and construct a flight path receiver prototype.  NASA IIP: take OAWL receiver as input at TRL-3, build into a robust lidar system, fly validations on the WB-57, exit at TRL-5.

7. Page_7 Ball Aerospace & Technologies Ball OAWL Receiver Design Uses Polarization Multiplexing to Create 4 Perfectly Tracking Interferometers Mach-Zehnder-like interferometer allows 100% light detection on 4 detectors Cat’s-eyes field-widen and preserve interference parity allowing wide alignment tolerance, practical simple telescope optics, and high spectral resolution Receiver is achromatic, facilitating simultaneous multi- operations (multi-mission capable: Winds + HSRL(aerosols) + DIAL(chemistry)) Very forgiving of telescope wavefront distortion saving cost, mass, enabling HOE optics for scanning and aerosol measurement 2 input ports facilitating 0-calibration patents pending

8. Page_8 Ball Aerospace & Technologies Completed Receiver / Permanently Potted Alignments (except for the final beamsplitter)

9. Page_9 Ball Aerospace & Technologies OAWL IRAD Receiver Development Status Receiver Status:  Optical design PDRcompleteSep. 2007  Receiver CDRcomplete Dec. 2007  Receiver performance modeled complete Jan. 2008  Designcomplete Mar. 2008  COTS Optics procurementcomplete Apr. 2008  Major component fabrication complete Jun. 2008 (IIP begins------------------------------------------------------------------------ Jul. 2008)  Custom optics procurementvendor issues Aug. 2008 ─ Custom optics procurementcomplete Dec. 2008 ─ Accommodating rework completeJan. 2009  Interferometric optics/mount bonding completeFeb. 2009  Interferometric alignment bond testsshrinkage / thermal issuesFeb. 2009 ─ New materials/process/mount designcompleteMay, 2009  Assembly and AlignmentcompleteOct. 2009  Preliminary testing complete Oct. 2009  Delivery to IIPcomplete Nov. 2009

10. Page_10 Ball Aerospace & Technologies OAWL System: NASA IIP

11. Page_11 Ball Aerospace & Technologies OAWL IIP Objectives Develop and Demonstrate an OAWL DWL system designed to be directly scalable to a space-based 3D-Winds lidar mission. Provide IRAD-developed receiver to IIP (entry TRL 3): Functional demonstrator for OAWL flight path receiver design principles and assembly processes. Shake & Bake Receiver: Validate receiver design approach and fabrication techniques suitable for airborne vibe environment. Integrate the OAWL receiver into a complete lidar system: add laser, telescope, frame, data system, isolation, and autonomous control software suitable for operation in a WB-57 pallet.  Raise OAWL technology to TRL 4 through ground validations alongside the a NOAA coherent Doppler lidar system.  Raise OAWL technology to TRL 5 through high altitude aircraft flight demonstrations.  Validate radiometric performance model as risk reduction for a flight design.  Validate the integrated system model as risk reduction for a flight design.  Provide a technology roadmap to TRL7

12. Page_12 Ball Aerospace & Technologies Receiver Vibration Testing - Acquisition Receiver and mounts instrumented with multiple accelerometers (blue wires) WB-57 Taxi, takeoff and landing (TTOL) shock/vibe level testing (1.78 gRMS) showed the adjustable beamsplitter needed staking to prevent alignment drifts, but the permanent interferometer alignment potting method appears stable at these levels. Operational vibe (0.08 gRMS) effects are within expectations; not expected to affect WB-57 wind measurement performance Audio speaker used to excite on organ pipe mode within the interferometer to repeatably sample the whole phase space.

13. Page_13 Ball Aerospace & Technologies Integrated Model Process Developed at BATC  Goals: ─ <6 nm (0.11 rad phase error) vibration induced noise), 30 nm accep. ─ <5% visibility reduction due to thermoelastic distortions.  Main system modeling outputs ─ Fringe visibility ─ Phase noise Code V SolidWorks NASTRAN Aircraft PSD 6 References: M. Lieber, C. Weimer, M. Stephens, R. Demara, “Development of a validated end-to-end model for space-based lidar systems”, in SPIE vol 6681, U.N.Singh, Lidar Remote Sensing for Environmental Monitoring VIII, Aug 2007. M. Lieber, C. Randall, L. Ayari, N. Schneider, T. Holden, S. Osterman, L. Arboneaux, "System verification of the JMEX mission residual motion requirements with integrated modeling", SPIE 5899, Aug 2005. M. Lieber, C. Noecker, S. Kilston, “Integrated system modeling for evaluating the coronagraph approach to planet detection”, SPIE V4860, Aug 2002

14. Page_14 Ball Aerospace & Technologies Integrated Model – Design Iteration: Vibration-Induced Phase Noise Convergence on Specification 12345 0 0.5 1 1.5 2 2.5 3 3.5 Log OPD (nm) 1900 nm, initial hard mount 55/ 27 nm, 20 Hz isolators added, WC/ nom 12/ 8.5 nm, redesigned structure, WC/ nom WC = Worst case Requirement: <1m/s/shot/100  s Random dynamic error with WB-57 excitation (12nm, goal 8.5nm) Final design Prediction Feb. 2008 : 8.5 nm RMS jitter, exceeding req. and meeting goal, suggests performance dominated by intensity SNR, not vibration environment While current result does not match the original model predictions, the receiver was modified to include the plate beamsplitter, and the FEM has not yet been integrated into the model. Also, real measurements have a small amount of measurement noise that is not accounted in the model. Conservative application of an appropriate MUF: the model and modeling process appear validated. IIP Upshot: ~6000 pulse returns (30s) will be averaged per wind profile suggesting the operational vibe induced errors appear to be <~0.03 m/s (10 km range) per profile therefore not significant for IIP Current result: ~17/34 nm RMS (10/20 km ranges) Model Uncertainty Factor (MUF) for similar analysis modeling based on comments from Gary Mosier GSFC

15. Page_15 Ball Aerospace & Technologies Summary of effective velocity error due to measured response to simulated WB-57 vibe environment Vibe axis OPD Standard Deviation (10/20 km) Velocity precision - per shot Precision w/ 1-second averaging Precision w/ 30-second averaging X15/31 nm2.3/4.6 m/s16/33 cm/s3/6 cm/s Y19/38 nm2.8/5.6 m/s20/40 cm/s3.7/7.4 cm/s Z7/13 nm1.0/2.0 m/s7/14 cm/s1.3/2.6 cm/s

16. Page_16 Ball Aerospace & Technologies IIP System Integration Design for WB-57 Pallet  The OAWL system is integrated in the WB-57 aircraft using one pressurized 6 foot pallet  The pallet houses the optical system, electronics, and thermal control OAWL Optical System Pallet Flight Direction

17. Page_17 Ball Aerospace & Technologies OAWL Pallet Configuration 1. Laser Power Supply Pallet Frame Double Window Laser Wire Rope Vibration Isolators Telescope Primary Mirror Sub-Bench with Depolarization Detector Receiver Telescope Secondary Mirror Chiller Optic Bench 3. Data Acquisition Unit 4. Separate suspension system 2. Power Condition Unit Electronics Rack

18. Page_18 Ball Aerospace & Technologies OAWL Transceiver Optical System Ball Aerospace & Technologies Interferometer Detectors (10) Telescope Laser Zero-Time/OACF Phase Pulse Pre- Filter Field Stop and Focus Coaxial Bistatic R/T Alignment Likely etalon location for complete IDD molecular/aerosol DWL

19. Page_19 Ball Aerospace & Technologies OAWL IIP System – Asssembled and Aligned Temporary Laser (50  J/pulse, 523 nm) X Temporary Laser (2.5  J/pulse, 532 nm) 3 ns pulse  5X bandwidth X 7 months delay in the primary laser delivery led to several attempts to use surrogate lasers to shake out integrated system bugs – the October WB-57 clock is ticking

20. Page_20 Ball Aerospace & Technologies Beam Expander Coating damage on the secondary due to 355nm pulse energy --- different coating vendor met specs Other issues addressed included: pulse width pulse energy bandwidth waveplate function residual 1  m

21. Page_21 Ball Aerospace & Technologies Complete IIP OAWL DWL System Fibertek laser installed and aligned T0T0 To atm

22. Page_22 Ball Aerospace & Technologies Pre-ground-validation Full System First Light Rooftop Tests (532nm) T 0 Wideband (pulse) optical quadrature (~32 MHz, measured) T 0 (local) T 600ns (90m range hard target) 20s Record of Raw 4-channel Signals Demonstrates OAWL receiver and laser transmitter are working well together (with a plane wavefront)

23. Page_23 Ball Aerospace & Technologies Pre-ground-validation Full System First Light Rooftop Tests (532nm) T0T0 T 600ns Phase   Seconds Target Tracks T 0 Auto- covariance Phase T 0 ~80% T 600ns ~20% Deminished due to poor Near-range overlap, and Contrast T 0 (reminder) Phase   T 0 -T 600ns 1-sec average a field-widening alignment issue under investigation

24. Page_24 Ball Aerospace & Technologies OAWL IIP Status Summary Program start, TRL 3 complete Jul. 2008TRL-3 IRAD receiver delivered to IIP complete Nov. 2009 Receiver shake and bake (WB-57 level) complete Nov. 2009 System PDR/CDR complete Feb./Mar. 2009 Lidar system design/fab/integration complete Jul. 2010  Ground validations completedplannedOct. 2010TRL-4  Airborne validations complete (TRL-5)plannedDec. 2010TRL-5  tech road mapping (through TRL7) plannedMay 2011  IIP Complete June 2011 Current Status

25. Page_25 Ball Aerospace & Technologies Leg 1 Leg 2 Multipass ** Wind profilers in NOAA operational network Platteville, CO Boulder, CO Houston, TX OAWL Validation Field Experiments Plan 1. Ground-based-looking up  Side-by-side with the NOAA mini-MOPA Doppler Lidar 2. Airborne OAWL vs. Ground-based Wind Profilers and mini-MOPA  15 km altitude looking down along 45° slant path (to inside of turns.  Variety of meteorological and cloud conditions over land and water September 2010 October 2010 NOAA mini-MOPA Coherent Doppler Lidar OAWL System Some curtailment of planned flight hours is in planning due to WB-57 cost increases, certification details, lack of complete pallet info, and pallet mods.

26. Page_26 Ball Aerospace & Technologies OAWL and NOAA mini-MOPA comparison site (ASAP after the integration tests are complete) General plan:  LOS comparisons between OAWL and NOAA’s mini-MOPA Doppler lidar.  OAWL ─ Will be located inside the newly rebuilt Table Mountain T2 building ─ Enclosed facility with 2 windows providing eastern and northern/northeastern views  mini-MOPA (longer performance comparison range) ─ Container on trailer parked outside. ─ LOS pointing may be interspersed with VAD scans to provide contextual wind information

27. Page_27 Conclusions The dual-wavelength, field-widened, OAWL receiver has been successfully completed and delivered to the IIP for lidar system integration. Receiver testing showed that the receiver tolerates WB-57 Taxi, Takeoff, and Landing shock and vibe, and the data suggest that the receiver can actually operate with reduced performance under these extreme conditions. The receiver performs near expectations during operational vibe conditions. The IIP lidar system has been fully assembled with final laser, aligned. First light acheived. Autocovariance phase from hard target tracks T 0 phase. Testing and final alignments are in progress in prep for validations.  Ground validations testing expected in September 2010. These are critical precursors to flight execution (TRL 4).  Aircraft plans in place and flight conops understood.  WB-57 flight tests remain on track for October 2010 (TRL 5) Ball Aerospace & Technologies

28. Backups

29. Page_29 Ball Aerospace & Technologies Data System Overview  Data system architecture ─ Based on National Instruments PXI Chassis ─ Utilizes COTS Hardware  Challenges & Solutions ─ Reduced air pressure at altitude degrades heat removal ability of stock cooling fans  Upgrade cooling fans  Test system in altitude chamber ─ Jacket material used in COTS cables is PVC, which is not permitted on WB-57  Utilizing NI terminal strip accessories where possible  Fabricating cables made from allowable jacket materials ─ Data Flow ~ 0.6 GB/minute  New 256 GB SSD Ball Aerospace & Technologies

30. Page_30 Ball Aerospace & Technologies Optical Autocovariance lidar (OAL) approach - Theory  No moving parts / Not fringe imaging  Allows Frequency hopping w/o re-tuning  Simultaneous multi-  operation Optical Autocovariance Wind Lidar (OAWL): Velocity from OACF Phase: V = *  * c / (2 * (OPD)) OA- High Spectral Resolution Lidar (OA-HSRL): A = S a * C aA + S m * C mA,  = S a * C a  + S m * C m   Yields: Volume extinction cross section, Backscatter phase function, Volume Backscatter Cross section, from OACF Amplitude Pulse Laser d 2 d 1 Detector 1 2 3 Data System CH 1 CH 3 CH 2 From Atmosphere Phase Delay mirror Beam Splitter Receiver Telescope Prefilter OPD=d 2 -d 1 Simplest OAL (Not the IIP config) Frequency  = phase shift as fraction of OACF cycle

31. Page_31 Ball Aerospace & Technologies Ball Space-based OA Radiometric Performance Model – Model Parameters Using : Realistic Components and Atmosphere LEO Parameters WB-57 Parameters Wavelength 355 nm, 532 nm 355 nm, 532 nm Pulse Energy 550 mJ 30 mJ, 20 mJ Pulse rate 50 Hz 200 Hz Receiver diameter1m (single beam) 310 mm LOS angle with vertical 45 0 45° Vector crossing angle 90 0 single LOS Horizontal resolution* 70 km (500 shots) ~10 km (33 s, 6600 shots) System transmission 0.35 0.35 Alignment error5  R average 15  R Background bandwidth 35 pm 50 pm System altitude400 km top of plot profile Vertical resolution0-2 km, 250m 100m (15m recorded) 2-12 km, 500m 12-20 km, 1 km Phenomenology CALIPSO model CALIPSO model -scaled validated CALIPSO Backscatter model used. ( -4 molecular, -1.2 aerosol) Model calculations validated against short range POC measurements. Volume backscatter cross section at 355 nm (m -1 sr -1 ) Altitude (km)

32. Page_32 Ball Aerospace & Technologies OAWL – Space-based Performance: Daytime, OPD 1m, aerosol backscatter component, cloud free LOS Threshold/Demo Mission Requirements 250 m 500 m 1km Vertical Averaging (Resolution) Objective Mission Requirements

33. Page_33 Ball Aerospace & Technologies Looking Down from the WB-57 (Daytime, 45°, 33s avg, 6600 shots)