Airborne Pulsed 2-Micron Direct Detection Lidar for CO2

Column Measurement

Upendra Singh1, Jirong Yu1, Mulugeta Petros1, Tamer Refaat1, Ruben Remus1, James J, Fay1, and Karl Reithmaier2

1NASA Langley Research Center, MS 433, Hampton, Virginia 3Science System &Applications, Inc, One Enterprise Parkway, Hampton, Virginia

*  Upendra.N.Singh@nasa.gov  

Acknowledgement: NASA Earth Science Technology Office (ESTO)

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•  Objec&ve  •  Develop  a  high  energy  double-­‐pulsed  2-­‐micron  direct  detecDon  IPDA  lidar  

system  to  demonstrate  airborne  atmospheric  CO2  measurements  

•  Background  •  Spectroscopy  and  IPDA    simula&on  •  2-­‐micron  double  pulsed  IPDA  lidar    •  IPDA  Ground  Tes&ng  •  IPDA  lidar  Airborne  Demonstra&on  •  Future  Work  •  Summary  and  Conclusions  

Outline  

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Atmospheric  CO2  Increase  

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Missing  CO2  Sink?  

base

d on

LeQ

uere

et a

l., 2

009

Anthropogenic activities have added >200 Gt C to the atmosphere since 1958 o  less than half of this CO2 is staying in the atmosphere o  where are the missing CO2 sinks?

CO2  A

mou

nt  (G

tC/yr)  

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Co-Is/Partners: Jirong Yu, Mulugeta Petros, Syed Ismail, NASA LaRC

Key Milestones

Objective

•  Develop, integrate and demonstrate a 2-micron pulsed Integrated Path Differential Absorption Lidar (IPDA) instrument CO2 Column Measurement from Airborne platform

•  Conduct ground validation test to demonstrate CO2 retrieval •  Conduct engineering test flights to demonstrate CO2 retrieval from UC-12 aircraft •  Conduct post flight data analysis for the purpose of

evaluation of CO2 measurement capability

Approach: •  Repurpose existing hardware including previously

developed transmitter, receiver and data acquisition system

•  Complete fabrication of transmitter, wavelength control and receiver units assembly

•  Integrate existing and to be developed subsystems into a complete breadboard lidar system

•  Fabricate a mechanical structure and integrate completed subsystem

•  Design of laser transmitter assembly 10/12 •  Design, manufacture and assembly of receiver 04/13 •  Integrate subsystems into breadboard lidar system 06/13 •  Conduct ground test of the integrated lidar assembly 07/13 •  Integrate lidar system on UC-12 aircraft 11/13 •  Conduct post flight data analysis 09/14

Development  of  a  Double-­‐Pulsed  2-­‐micron  Direct  Detec&on  IPDA  Lidar    for  CO2  Column  Measurement  from  Airborne  PlaMorm  

Mobile and Airborne 2µm IPDA LIDAR system

TRLin = 3 TRLout = 5 (AIRCRAFT)

PI:  Upendra  N.  Singh,  NASA  LaRC  

2-­‐µm  Pulsed  Direct  Detec&on  CO2  IPDA  (Airborne)  

Telescope

Receiver  

Integrated  2µm  Pulsed  IPDA  Lidar  for  Airborne  CO2 Column  Measurement  

24”X26”X30”

Phase  I

Telescope Thermal  Control

Digitizer Wavelength  Controller

Laser Laser  

Detector

Phase  II

Phase  III

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Spectroscopy  

2.0504 2.0505 2.0506 2.0507 2.0508 2.0509 2.051 2.0511 2.0512 2.0513 2.0514

x 10-6

10-26

10-25

10-24

10-23

10-22

10-21

Wavelength

Cros

s Se

ctio

n [c

m2 ]

cdwvOn-line 1GhzOn-line 2GhzOn-line 3GhzOn-line 4GhzOn-line 5GhzOn-line 6GhzOff-line

𝚫𝝈↓𝒄𝒅 =𝒇𝒏(𝝀,𝑷,𝑻)

1 2 3 4 5 6 70

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

10.94553

0.61145

0.37403

0.23527

0.155080.10598

On-Line Shift [GHz]

Opt

ical

Dep

th

Double-Path Differential Optical Depth

Optical Depth (Ground)

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

1

2

3

4

5

6

7

8

9

10

11

Weighting Function

Altit

ude

[km

]

On-Line 1GHzOn-Line 2GHzOn-Line 3GHzOn-Line 4GHzOn-Line 5GHzOn-Line 6GHz

Pressure-Based Weighting- Functions (Airborne)

•  Standard models are used for estimating optical depth, return pulse strength, SNR and errors for any operating condition.

•  Modeling and meteoro-logical data are used for XCO2 derivation.

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2-­‐µm  IPDA  Lidar  Schema&c  

8  

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IPDA  Ground  Tes&ng:  IPDA  Integra&on  

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IPDA  Ground  Tes&ng:  Setup  &  Measurement  

TARGET

CAPABLE

IPDA LIDAR

LICOR

INCINERATOR

Differential optical depth– model and measurement

17:00 17:30 18:00 18:30 19:00 19:30 20:00 20:300.65

0.655

0.66

0.665

0.67

0.675

0.68

0.685

0.69

0.695

0.7

Time [hr:min]

CO2 d

OD

ModelPIN Laser Energy MonitorWindow Reflection

•  IPDA ground testing conducted at LaRC on 1/24/2014. •  Modeled CO2 optical depth was calculated from in-situ

sensor (LiCor) and CAPABLE measurements. •  IPDA measured CO2 optical depth was obtained from

•  PIN laser energy monitor with the hard target return.

•  Residual scattering (window reflection) with the hard target return.

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IPDA  Ground  Tes&ng:  Setup  &  Measurement  

TARGET

CAPABLE

IPDA LIDAR

LICOR

INCINERATOR

Dry mixing ratio IPDA vs (in-situ) Instrument

17:00 17:30 18:00 18:30 19:00 19:30 20:00 20:30400

405

410

415

420

425

430

Time [hr:min]

X cd

ModelWindow Reflection

•  Results from residual scattering better correlate to modeled differential optical depth

•  Residual scattering provides self-calibration capability for the CO2 IPDA lidar instrument

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IPDA  Ground  Tes&ng:  Setup  &  Measurement  

TARGET

CAPABLE

IPDA LIDAR

LICOR

INCINERATOR

17:00 17:30 18:00 18:30 19:00 19:30 20:00 20:30405

410

415

420

425

430

Time [hr:min]

X cd

ModelWindow Reflection

Dry mixing ratio IPDA (offset +8 ppm) vs (in-situ) Instrument

•  Results indicated profile matching with 8 ppm offset between in-situ and IPDA dry mixing ratio measurements

•  Offset attributed to detection system non-linearity (most probably digitizer)

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AircraV  Configura&on:  Instrument  

LIDAR

LICOR

CAPABLE

INCINERATOR

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10  Flights  in  March  &  April  2014  

Date   Purpose   Dura&on   Loca&on  

March  20   Instrument  Check  Flight  

2.1  hr   VA  

March  21   Engineering   2.7  hr   VA  

March  24   Engineering   3.0  hr   VA  

March  27   Early  morning   3.0  hr   VA  

March  27   Mid-­‐aRernoon   2.5  hr   VA  

March  31   Inland-­‐Sea   2.5  hr   VA,  NC  

April  02   Power  StaDon   2.4  hr   NC  

April  05   With  NOAA   3.7  hr   NJ  

April  06   Power  StaDon   3.0  hr   NC  

April  10   Late  aRernoon   2.3  hr   VA  

•  Aircraft had temperature, pressure, humidity sensors, LiCor and GPS •  Some of the flights were supported by balloon launches

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IPDA  Airborne  Tes&ng:  Sample  Return  Signals  

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6500

1000

1500

2000

2500

3000

3500

dOD

Altit

ude

[m]

US ModelIPDA ModelHigh Gain Channel + Window

20:00 20:15 20:30 20:45 21:00 21:150.2

0.4

0.6

0.8

1

1.2

High gain channel + High gain Window, 100-Avg

Time [hr:min]

dOD

MeasurementModel

•  IPDA airborne testing was conducted on April 10, 2014. •  Modeled CO2 optical depth was calculated from CO2 in-situ sensor (LiCor) and aircraft

meteorological sensors at different altitude. •  Another modeled CO2 optical depth was calculated using the US Standard Atmosphere at

different altitude. •  Measured CO2 optical depth was calculated from the IPDA data (black and blue dots), with

100 shot average, at different altitude. •  Energy monitoring through residual scattering and vegetation/soil ground hard target.

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IPDA  Airborne  Tes&ng:  Sample  Return  Signals    

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000-0.2

0

0.2

0.4

0.6

Sign

al [V

]

Digitizer Samples

1530 m, 104 V/A

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 100000

0.5

1

1.5

2

Sign

al [V

]

3988 m, 105 V/A

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 100000

0.5

1

1.5

2

Sign

al [V

]

6125 m, 105 V/A

14:11 14:12 14:13 14:14 14:15 14:16 14:17 14:181480

1490

1500

1510

1520

1530

1540

1550

Time [min:sec]

Rang

e [m

]

GPS AltitudeIPDA Range MeasurementGPS Line-of-Sight

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.80

1000

2000

3000

4000

5000

6000

7000

dOD

Altit

ude

[m]

NOAA 4GHzNOAA 3GHzIPDA LidarUSA 3 & 4GHz

•  NOAA air sampling and IPDA lidar optical depth comparison.

•  Return signal samples from different altitudes up to 6km.

•  IPDA range measurements compared to on-board GPS.

Objective

Key Milestones Approach

4/14 IIP-13-0048

Triple-­‐Pulsed  2-­‐µm  Direct  Detec&on  Airborne  Lidar  for  Simultaneous  and  Independent  CO2  and  H2O  Column  Measurement  –  Novel  Lidar  Technologies  and  Techniques  with  Path  to  Space  

PI: Upendra Singh, NASA LaRC

Co-Is/Partners: Ken Davis, Penn State Univ; Jirong Yu, Mulugeta Petros, LaRC; Floyd Hovis, Fibertek, Inc.

•  Demonstrate and validate simultaneous and independent measurement of the weighted-average column dry-air mixing ratios of carbon dioxide (XCO2) and water vapor (XH2O) from an airborne platform

•  Design and fabricate a space-qualifiable, fully conductively-cooled, triple-pulsed, 2-µm laser transmitter

•  Design and develop wavelength control system for rapid and fine tuning of the three sensing lines of the CO2/H2O Integrated Path Differential Absorption (IPDA) lidar

•  Integrate laser transmitter with receiver to develop the triple-pulsed 2-µm direct detection IPDA lidar

•  Conduct extensive ground and airborne column CO2/H2O measurement and validate with in-situ sensors

•  Team with industry to utilize extensive space-flight laser development expertise to build a unique triple-pulsed 2-µm laser

•  Develop a novel, lightweight, frequency agile, wavelength tuning and locking system for triple-pulsed IPDA Operation

•  Integrate state-of-the-art laser transmitter to the existing and upgraded receiver system and strengthen for stable flight operation

•  Conduct initial ground testing and validation of the IPDA lidar from a mobile lidar trailer

•  Conduct extensive ground and airborne column CO2/H2O measurement and validate with in-situ sensors

TRLin = 3 TRLout = 5

An example of space-qualifiable, fully conductively-cooled 2-µm laser packaging from ACT 11

Integrated 2-µm CO2/H2O Airborne packaged IPDA Lidar

•  Complete the preliminary triple pulse laser optical, mechanical, thermal and structure design and analysis

•  Complete laser wavelength control unit design •  Complete laser transmitter design, and mechanical lidar system design and breadboard testing

•  Complete fabrication and testing of laser transmitter and wavelength control unit

•  Integrate laser transmitter with wavelength control unit •  Complete lidar integration, and ground test

•  Conclude CO2/H2O airborne lidar demonstration and final report

12/14 03/15 09/15 07/16 09/16 03/17 06/17

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Table 1. Comparison of CO2 state-of-the-art 2-µm current and proposed technology with space requirement

Current Technology Proposed Technology Projected Space Reqirement [2]

Laser Transmitter Single Laser Single Laser Two Lasers

Technology Liquid-Cooled, Airborne laser

Conductively-Cooled Space Qualifiable laser

Column CO2 Space Mission

Technique Double-Pulse Triple-Pulse Single-Pulse Laser Wavelength (µm) 2.051 2.051 2.051 Pulse Energy (mJ) 1st/2nd/3rd Pulse 100/30 Double Pulse 50/15/5 Triple Pulse 40/5 Single Pulse

Pulse Repetition Rate (PRF) 10 50 50

Power (W) 1.3 3.5 2.25

Pulse Width FWHM (ns) 200 30-100 50

Optical to Optical Efficiency (%) 4.0 5.0 5.0

Wall Plug Efficiency (%) 1.44 2.1 >2.0

Delay between pulses (200 µsec) 200 200 250+/-25

Transverse/Longitudinal Modes TEM00/Single Mode TEM00/Single Mode TEM00/Single Mode

Pulse Spectral Width FWHM (MHz) 2.2 4-14 > 60

Beam Quality (M2) 2 2 < 2

Frequency Control Accuracy (MHz) 0.3 0.3 0.2

Seeding Success Rate /Spectral Purity (%) >99/99.9 >99/99.9 >99/99.9

Detector

Material InGaAs HgCdTe N/A Structure Pin photodiode eAPD APD Quantum Effficiency (%) 68 80 75 Excess-Noise-Factor --- 1.1 1.5 Noise-Equivalent-Power (fW/Hz1/2) 200 8 100

2-­‐µm  CO2  IPDA  Path  to  Space  

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Summary  and  Conclusions  

Ø  A 2-micron double-pulsed, high energy IPDA lidar system has been developed Ø  2-m CO2 IPDA lidar modeling estimates instrument performance and

calculates weighting function for deriving XCO2. Ø  Preliminary analysis of ground based hard target measurement demonstrates

the 2-m CO2 IPDA lidar capability of measuring CO2 optical depth and deriving XCO2.

Ø  The IPDA instrument was operated on NASA B-200 aircraft through different conditions

Ø  IPDA capability was demonstrated from airborne platform Ø  The measurement includes ranging capability with 1 m precision Ø  Observed single-shot signal-to-noise ratio from hard target larger than 200 Ø  Detailed data analysis is in progress Ø  Future work towards developing a triple-pulsed IPDA lidar system is progressing

2-m IPDA Lidar Team members C. Boyer, B. Culliton, L. Cowen, J. Fay, W. Johnson, S. Johnston, M. Jones, E. Modlin, L. Murchison, I. Pang, P. Manhart, T. Notari , M. Petros , K. Reithmaier, T. Refaat, R. Remus, D. Reichle, S. Salvatore, U. Singh, J. Yu

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Publica&on  List  

1.  J. Yu, M. Petros, K. Reithmaier, Y. Bai, B. Trieu, T. Refaat, M. Kavaya, U. Singh and S. Ismail, “A 2-micron pulsed integrated path differential absorption lidar development for atmospheric CO2 concentration measurements”, 26th International Laser Radar Conference (ILRC), Porto Heli, Greece, 2012.

2.  U. Singh, J. Yu, M. Petros, T. Refaat and K. Reithmaier, “Development of a pulsed 2-micron integrated path differential absorption lidar for CO2 measurements”, Invited, Proc. of SPIE, Vol. 8872, 997209, 2013.

3.  U. Singh, J. Yu, M. Petros, T. Refaat, K. Reithmaier, T. Kurosu, C. Miller and S. Dinardo, “Double-pulsed 2-micron integrated path differential absorption lidar development and column CO2 measurement from ground and airborne platform”, 10th International Workshop on Greenhouse Gas Measurements from Space, ESA-ESTEC, Noordwijk, The Netherlands, 2014.

4.  U. Singh, J. Yu, M. Petros, T. Refaat, R. Remus, J. Fay and K. Reithmaier, “Column CO2 measurements from an airborne solid-state double-pulsed 2-micron integrated path differential absorption lidar”, International Conference on Space Optics, Tenerife, Canary Islands, Spain, 2014.

5.  J. Yu, M. Petros, T. Refaat, K. Reithmaier, R. Remus, U. Singh, W. Johnson, C. Boyer, J. Fay, S. Johnson and L. Murchison, “2-micron pulsed direct detection IPDA lidar for atmospheric CO2 measurement”, First International Conference on Space-Based Lidar Remote Sensing Techniques and Emerging Technologies, Paris, France, 2014.

6.  T. Refaat, M. Petros, R. Remus, J. Yu and U. Singh, “Laser energy monitor for double-pulsed 2-m IPDA lidar applications”, Proc. of SPIE, Vol. 9246, 924619, 2014.

7.  U. Singh, J. Yu, M. Petros, T. Refaat, R. Remus, J. Fay and K. Reithmaier, “Airborne 2-micron double-pulsed integrated path differential absorption lidar for column CO2 measurement”, Proc. of SPIE, Vol. 9246, 924601, 2014.

8.  T. Refaat, M. Petros, R. Remus, J. Yu and U. Singh, “Self-calibration laser energy monitor validation for double-pulsed 2-m CO2 IPDA lidar applications”, in preparation, Optical Engineering.

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Thanks for your Attention