GEO Spacecraft Development by liuqingyan

VIEWS: 26 PAGES: 26

									     Ball Aerospace &
     Technologies Corp.




               OAWL Progress and Plans

 Christian J. Grund, Bob Pierce, Jim Howell, Miro Ostaszewski
Ball Aerospace & Technologies Corp. (BATC), cgrund@ball.com
            1600 Commerce St. Boulder, CO 80303

         Working Group on Space-based Lidar Winds
                        Desdin, FL
                       Jan. 28, 2009


          Agility to Innovate, Strength to Deliver
             Acknowledgements: The Ball OAWL Development Team




Jim Howell – Systems Engineer, Aircraft lidar specialist, field work specialist
Miro Ostaszewski – Mechanical Engineering
Dina Demara – Software Engineering
Michelle Stephens – Signal Processing, algorithms
Mike Lieber – Integrated system modeling
Chris Grund – PI system architecture, science/systems/algorithm guidance,
  electrical engineering
Carl Weimer – Space Lidar Consultant




                               Ball Aerospace & Technologies                      Page_2
   Optical Autocovariance Wind Lidar and the
Integrated Direct Detection Wind Lidar Concepts
             What is Optical Autocovariance Lidar?

Method:
• Interferometric direct detection lidar
• Instantaneous measurement of the phase and
amplitude of the optical autocovariance function
(OACF) about one Optical Path Difference (OPD)

Key Attributes:
• Very high spectral resolution feasible
• Self-referenced optical mixing
      • intensity measurements determine optical freq.
      • minimizes required electronic bandwidth
      • minimizes required signal processing power
      • Eliminates need to tune receiver to transmitter
      • Hardware-free compensation for LOS orbital V

Applications:
Doppler Lidar (wind profiles)
High Spectral Resolution Lidar (HSRL)
Differential Absorption Lidar (DIAL)


                                       Ball Aerospace & Technologies   Page_4
          Optical Autocovariance Wind Lidar (OAWL)


 The phase of the OACF for 0-
  velocity at 0-range is captured by
  locally sampling the outgoing
  pulse.

 The OACF is measured for the
  atmospheric return from each
  range bin.

 The wind velocity V is calculated
  from the difference in the OACF
  phase (Df) between the 0-velocity
  sample and each range return:
  V = l *Df * c / (2 * OPD)
  Df expressed as a fraction of 1 OACF period

                        Doppler Winds use the Phase of the OACF
                                    Ball Aerospace & Technologies   Page_5
                           Addressing the Decadal Survey 3D-Winds Mission with
                            An Efficient Single-laser All Direct Detection Solution

                                   Molecular WindsUpper atmosphere profile


                                  Etalon              OAWL                         Combined
      Telescope                  Molecular           Aerosol                         Signal   1011101100
                                 Receiver            Receiver                      Processing      Full
                                                                                                        Atmospheric
                                                         Aerosol Winds                                 Profile Data
              UV Laser                                Lower atmosphere profile

                                                     HSRL Aer/mol mixing ratio
Most Efficient: Integrated Direct Detection (IDD) wind lidar approach:
   Double-edge etalon strips and measures the molecular, rejects most of the aerosol component.
   OAWL HSRL retrieval determines residual aerosol/molecular mixing ratio
   Etalon processes molecular backscatter winds, corrected by HSRL from OAWL for aer/mol backscatter mixing ratio
   Result:
       ─ single-laser transmitter, single wavelength system
       ─ single simple, low power and mass signal processor
       ─ full atmospheric profile using aerosol and molecular backscatter signals
       ─ OAWL alone can measure both, however power*aperture*precision optimization is less efficient (a trade)
Ball Aerospace patents pending

                                               Ball Aerospace & Technologies                                         Page_6
OAWL Development Program
            Optical Autocovariance Wind Lidar (OAWL) Development Program



 Internal investment to develop the OAWL theory and implementable architecture,
  performance model, perform proof of concept experiments, and design and
  construct a flight path receiver prototype.


 Recent NASA IIP win will take OAWL receiver at TRL-3, build into a robust lidar
  system, fly on the WB-57, exit at TRL-5.




                               Ball Aerospace & Technologies                        Page_8
Ball Multi-wavelength OA Receiver
            IRAD Status




        Ball Aerospace & Technologies   Page_9
OAWL IRAD Receiver Design Uses Polarization Multiplexing
     to Create 4 Interferometers in the Same space


                                        • 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

                                        • Receiver is achromatic, facilitating
                                        simultaneous multi-l 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


         Ball Aerospace & Technologies patents pending
                                                                                 Page_10
    Solid Model of Receiver
     (detector covers removed)
- All aluminum construction minimizes DT, cost
          - Athermal interferometer design
                   - Factory-set operational alignment
                    for autonomous aircraft operation
                          - ≈100% opt. eff. to detector
                            - multi-l winds, plus HSRL
                              and depolarization for
                               aerosol characterization
                                   and ice/water cloud
                                      discrimination
                                  - Compatible with wind
                                 and HSRL measurements



                                   Detectors:
                                   1 532nm depolarization
                                   1 355nm depolarization
                                   4 532nm winds/HSRL
                                   4 355nm winds/HSRL
                                   10 Total

Ball Aerospace & Technologies                          Page_11
                OAWL Receiver Mechanical Components




A few simple components
    • Detector housings
    • Monolithic interferometer
    • Covers and base plate
mount to a monolithic base structure.
Detector amplifiers and thermal controls
are housed inside the base structure.
                            Ball Aerospace & Technologies   Page_12
Initial Static Interferometer Stability Tests

                        For these
                    measurements the
                    OAWL receiver is
                    supported on the
                    ends- worst case
                     support scinario




           Ball Aerospace & Technologies        Page_13
                      All Aluminum Interferometer Supported by Ends
            no isolation, before/after repeated bolting and unbolting of the bottom plate


Flat mirrors
Interferometer out
to TV Camera
                                                                                      2nd
                                                                                  Tightening



                                                   First
                                                tightening




       Bottom access plate removal: fringe tilt returns with reinstallation of bottom – GOOD!
       Static load: 2 kg suspended at center – no fringe shift or rotation - GOOD!
       Thermal: ~1 fringe side drift /hr in unprotected laboratory environment – GOOD!
                                         Ball Aerospace & Technologies                           Page_14
                  OAWL Receiver IRAD Progress Schedule and Status

Receiver Status (Ball internal funding):
 Optical design PDR                          complete                            Sep. 2007
 Receiver CDR                                complete                            Dec. 2007
 Receiver performance modeled                complete                            Jan. 2008
 Design                                      complete                            Mar. 2008
 COTS Optics procurement                     complete                            Apr. 2008
 Major component fabrication                 complete                            Jun. 2008
 (IIP begins------------------------------------------------------------------------ Jul. 2008)
 Custom optics procurement                   vendor issues                       Aug. 2008
 Custom optics procurement                   complete                            Dec. 2008
 Assembly and Alignment                      in progress                         Jan. 2009
 Preliminary testing                         scheduled                           Mar. 2009
 Delivery to IIP                             scheduled                     Late Mar. 2009

                                    Ball Aerospace & Technologies                                 Page_15
OAWL System IIP and Status




      Ball Aerospace & Technologies   Page_16
                                   OAWL IIP Objectives

 Demonstrate OAWL wind profiling performance of a system designed to be directly
  scalable to a space-based direct detection DWL (i.e. to a system with a meter-class
  telescope 0.5J, 50 Hz laser, 0.5 m/s precision, with 250m resolution).

 Raise TRL of OAWL technology to 5 through high altitude aircraft flight
  demonstrations.

 Validate radiometric performance model as risk reduction for a flight design.

 Demonstrate the robustness of the OAWL receiver fabrication and alignment
  methods against flight thermal and vibration environments.

 Validate the integrated system model as risk reduction for a flight design.

 Provide a technology roadmap to TRL7
                                 Ball Aerospace & Technologies                          Page_17
                                     OAWL IIP Development Plan

Shake & Bake Receiver: Validate system design                                         Short Interferometer Arm
                                                                                                                 Long Interferometer Arm

                                                                                                                       50% Beam
                                                                  Cross channel polarization              Polarizing Splitter
                                                                  Detectors (532nm and 355 nm)           Beam Splitter


Integrate the OAWL Receiver (Ball IRAD)                                                                                                            Polarizing
                                                                                                                                                  Beam Splitter

(entry TRL 3 (or 2.5 since the POC receiver uses same                                                                                             355nm Ch 3

   principles but is of a different architecture )
                                                                     Inp                                                                          and CH 4
                                                                        ut
                                                                           Lig                                                                    detectors
                                                                              ht
                                                                                 Co
                                                                                   up
                                                                                     lin
                                                                                        gA
                                                                                          rea

Into a lidar system
(add laser, telescope, frame,                                                                                           Lens


data system, isolation, and                                                          532nm Ch 1
                                                                                                                        Harmonic
                                                                                                                        Separator
                                                                                                                                     532nm Ch 3
                                                                                     and CH 2 Polarizing     355nm Ch 1
autonomous control software                                                          detectors Beam Splitter and CH 2
                                                                                                             detectors
                                                                                                                                     and CH 4
                                                                                                                                     detectors

in an environmental box)




Validate Concept, Design, and Wind Precision
  Performance Models from the NASA WB-57
  aircraft
(exit TRL 5)

                                        Ball Aerospace & Technologies                                                                             Page_18
                           IIP System Concept for WB-57 Tests

                                                                          Pallet Cover

                                                      6’ Pallet
                                                 (WB-57 form factor)


                                                         Custom Pallet-
                                                         Mounting Frame


IRAD - Receiver                                                 Telescope




         Laser
         Source


     Custom Window


  Ball Aerospace & Technologies                                                    Page_19
                                 OAWL Validation Field Experiments


1. Ground-based-looking up
Side-by-side with the NOAA High Resolution
  Doppler Lidar (HRDL)
                             Fall 2009
                                                                   Platteville, CO




2. Airborne OAWL vs. Ground-
  based Wind Profilers and HRDL
                                                                                     Houston, TX
(15 km altitude looking down along 45° slant         Boulder, CO

  path (to inside of turns).                                                                   Leg 1
                                                                                               Leg 2
Many meteorological and cloud conditions                                                       Multipass
  over land and water)
                              Fall 2010

                                               ** Wind profilers in NOAA operational network

                                   Ball Aerospace & Technologies                                   Page_20
              Taking an OAWL Lidar System Through TRL 5


NASA/ESTO Funded IIP Plan:
 Program start, TRL 3                                   complete              Jul. 2008

 IRAD receiver delivered to IIP                         planned               Mar. 2009

 Receiver shake and bake (WB-57 level)                  assume 3/1/09 delivery Mar. 2009

 System PDR/CDR                                         planned               Feb./Mar. 2009

 Lidar system design/fab/integration                    design in progress    Oct. 2009

 Ground Tests completed                                 planned               Mar. 2010

 Airborne tests complete (TRL-5)                        planned               Dec. 2010

 Receiver shake and bake 2 (launch level)               planned               Apr. 2011

 tech road mapping (through TRL7)                       planned               May 2011

 IIP Complete                                           planned               June 2011

                                    Ball Aerospace & Technologies                               Page_21
                             Conclusions

 Optical Autocovariance Wind Lidar offers high performance wind
measurements from aerosol backscatter at 355 nm.

 OAWL aerosol and Double-edge Etalon molecular wind measurements can
be made simultaneously and efficiently at 355nm.

 IRAD Receiver: All components meeting required specs in house, final
assembly/alignment in progress. Vendor performance issues overcome.

 IIP in progress: OAWL Receiver TRL 2.5  OAWL system  Ground Tests
                                          Airborne Tests  TRL 5

 Plan ground testing in late Fall 2009 along side NOAA Doppler lidar

 Plan WB-57 flight tests in Fall 2010
                                                                         Page_22
                             Ball Aerospace & Technologies
Backups
       Ball-internally funded Space-based OA Radiometric Performance Model –
       Model Parameters: Realistic Components and Atmosphere

LEO Model Parameters:                                              20

                                                                                                          aerosol
Wavelength                 355 nm, 532 nm
                                                                                                          molecular
Pulse Energy               550 mJ                                  15
Pulse rate                 50 Hz




                                                   Altitude (km)
                                                    Altitude, km
Receiver diameter          1m (single beam)
LOS angle with vertical   450                                      10

Vector crossing angle     900
Horizontal resolution*    70 km (500 shots)
                                                                    5
System transmission        0.35
Alignment error            5 mR average
                          (NOTE: ~50 mR allowed)                    0 -8         -7           -6           -5          -4
Background bandwidth      35 pm                                     10        10            10           10         10
Orbit altitude            400 km                                          backscatter cross section at 355 -1 sr-1
                                                                   Volumebackscatter coefficient at 355 nm mnm (m-1sr-1)

Vertical resolution       0-2 km, 250m                             l-scaled validated CALIPSO Backscatter
                          2-12 km, 500m                            model used. (l-4 molecular, l-1.2 aerosol)
                          12-20 km, 1 km                           Model calculations validated against short
Phenomenology             CALIPSO model                            range POC measurements.
                                                                           Ball Aerospace & Technologies              Page_24
                                     OAWL – Space-based Performance:
                                     Daytime, OPD 1m, aerosol backscatter component, cloud free
                                     LOS
                                                          20
                                                          18
Vertical Averaging (Resolution)




                                   1km                    16
                                                          14
                                          Altitude (km)



                                                          12
                                                          10
                                                                                                            355 nm

                                  500 m
                                                          8                                                 532 nm
                                                                                                            Demo and Threshold
                                                          6                                                Objective

                                                          4                                       Threshold/Demo Mission Requirements

                                                          2                                  Objective Mission Requirements
                                  250 m
                                                          0
                                                               0.1               1                    10                         100
                                                               Projected Horizontal Velocity Precision (m/s)
                                                                      Ball Aerospace & Technologies                                    Page_25
Looking Down from the WB-57 (Daytime, 45°, 33s avg, 6600 shots)



                18
                16
                14
Altitude (km)




                12
                10
                 8
                 6                                             355nm
                 4                                             532nm
                 2
                 0
                     0   0.1        0.2    0.3     0.4    0.5          0.6
                                   Velocity Precision (m/s)

                               Ball Aerospace & Technologies                 Page_26

								
To top