lunacruz_atmospheric processing sarp presentation

8/14/2019 LunaCruz_Atmospheric Processing SARP Presentation

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Daniel S. TkacikDepartment of Earth and Atmospheric Sciences, GeorgiaInstitute of Technology

Yatza Luna-CruzNOAA Center for Atmospheric Sciences, Howard University

Atmospheric Processing forMASTER Imagery using

Chemical Transport Models


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Outlin


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Introducti

The signal detected by a remote sensor is theresult of three main radiative contributions.

1. Atmosphere

2.Target3. Background

TOA radiance

TOA solar irradiance RS

to

Verhoef, 2008

Transmitted

ScatteredorReflected

Backgrou Target

12233


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Motivati

Atmospheric effects place a bias on remote

sensing measurements, preventing the truesurface measurements from being retrievedremotely.

In order to account for this bias, anatmospheric correction must beimplemented to constrain atmospheric effects


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Objecti

Constrain atmospheric effects over

Monterey Bay and implement the correctionin the retrieval of surface-relevant

parameters in order to assess its impact.


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Data and

Selection of point of

interest.

Running and processing the outpdata.

The analysis.

Acquisition of MODTRAN initializationparameters.

Steps for Atmospheric processing:

Convert sensor data in radiance unitsAtmospheric Model to estimate atmosphericpropertiesEstablish Relationships (TRa and SRe)Derive Reflectance from target Radiance


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Selection of Point of

Monterey Bay, CA

Lat: 36 57 34.99 N, Long: 121 56 2.32 W

Date: 22/07/2009Time start: 23:48:43, Time end: 23:53:31DC-8 Flight Number: 09-010-00MODIS/ASTER airborne simulator (MASTER)

image:

MASTER True Color -

Flight Track


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Data and

Selection of point ofSelection of point ofinterest.interest.

Running and processing the outpRunning and processing the outpdata.data.

The analysis.The analysis.

Acquisition of MODTRAN initialization

parameters.


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MODTRAN4: Brief

MODTRAN: MODerate spectral resolutionatmospheric TRANsmittance algorithm andcomputer model

Developed by Air Force Research Labs (AFRL) in

collaboration with Spectral Sciences, Inc. (SSI). Used to model the spectral absorption,transmission, emission, and scatteringcharacteristics of the atmosphere.

- Accomplished by modeling the atmosphere asa set of horizontaly homogeneous layers.

MODTRAN Interface

A MODTRAN interface was used to simplify the useof MODTRAN by providing a graphical user interfacefor the creation of input files.


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MODTRAN4:


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Atmospheric Models and

18-layer vertical profiles of model

meteorological conditions were extracted in theWeather Research and Forecasting model (WRF)v. 2.2.

PressureTemperature

Dew point Wind speed

Using the STEM-2K3 chemical transport model[Carmichael et al., 2003], in conjunction withWRF meteorology, gas concentrations at each

vertical layer were extracted. O3 CO

NO SO2

NO2 NH


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Atmospheric Models and

Example of a tape5 file Mod/Obs Gas Settings,Radiance Mode


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Data and


Running and processing the outpdata.


Acquisition of MODTRAN initializationAcquisition of MODTRAN initialization

parameters.parameters.


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Running MODTRAN

Tape 7


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Processing Output

Dr. Nick Clinton

processes theMODTRAN4 output

data (.tp7 files)


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Processing Output Techniques from Verhoef and Bach, 2003 wereimplemented in the generation of six atmospheric

parameters that describe the alteration of ground-emitted and reflected radiation by atmosphericeffects.

Six Atmospheric Parameters

Derived from MODTRAN4 runs for eachwavelengthDescribe the interaction of the whole


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Data and


Running and processing the outpRunning and processing the outpdata.data.


Acquisition of MODTRAN initializationAcquisition of MODTRAN initialization

parameters.parameters.


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Resul

Comparison of two sets ofresults:

(3)Default gas settings


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Results: Simulated


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Results:

ENVI is an environmental imagingprogram used to process and analyzegeospatial imagery.

Band Math, a special tool in ENVI, is used

Resul


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True Color Default True Color Mod/Obs

DifferencesNo visible differences were found in the true color images.

Resul


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Temperature

Differences: Default gases retrieved higher temperatures than the

model/observations gases.

C (0.14%), UN (0.29%), DN (0.24%), LON (0.36%) and RON

Temp Default Temp Mod/Obs

Cente

Up

Down

Left

off

Right

off


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Normalized DifferenceVegetation Index

Characteristics:(0.3 0.8) dense vegetationcanopy

Negative values clouds and snowLow positive values free standingwater

A measure that directly relate the photosyntheticcapacity and hence energy absorption of plant

NDVI = NIR Red

NIR +

Resul


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NDVI Default NDVI Mod/Obs

DifferencesInput gases predict higher NDVI than default gasesDifference greater over the greatest NDVINDVI is saturated at high valuesSeparation of high-reflectance pixels is possible with

Resul

LAI

NDVI


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Fluorescence LineHeight

Characteristics:Negative at low or nil chlorophyllconcentrations

FLH = L6 {L7 +(L5 L7) *[( 7 - 6)/( 7 -

)]

A relative measure of the amount of radianceleaving the sea surface in the chlorophyllfluorescence emission band, which is presumably

Resul


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FLH Default FLH Mod/Obs

Differences Visible difference but the difference does not

yield different conclusion

Resul

C l i


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Conclusi

Applying an Atmospheric Correction toMASTER data makes a difference in thereflectance some large, some small.

Correction allows for the ability to distinguishbetween pixels with strong signals, notably inthe retrieval of NDVI.

MASTERs overestimation of surfacetemperature can be explained throughcorrection.

F W k &


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Future Work &

Improve atmospheric profile retrieval methods.Validate with in-situ measurements.

Apply correction to many cases to gainknowledge of its sensitivity to different input

parameters as well as how the resultingreflectance data affect surface properties (FLH,NDVI, etc.)

R f


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ReferenCarmichael, G.R., et al. (2003). Regional-scale chemical transport modeling in support ofintensive field experiments: overview and analysis of the TRACE-P observations. Journalof Geophysical Research 10.1029/2002JD003117.

Carter, W.P.L. (2000). Documentation of the SAPRC-99 chemical mechanism for VOCreactivity assessment. Final Report to the California Air Resources Board, Contracts 92-32 and 95-308, Riverside, CA (available athttp://www.engr.ucr.edu/~carter/absts.htm#saprc99).

CGRER (2008). ARCTAS emissions data (available athttp://www.cgrer.uiowa.edu/arctas/emission.html). Streets, D. G., et al. (2003), Aninventory of gaseous and primary aerosol emissions in Asia in the year 2000, J.

Geophys. Res., 108(D21), 8809, doi:10.1029/2002JD003093.

D. Schlpferand D. Odermatt, MODTRAN for Remote Sensing Applications UserManual, ReSe, Version 3, (2006).

Letelier, R.M. and M.R. Abbott, An analysis of chlorophyll fluorescence algorithms for themoderate resolution imaging spectrometer (MODIS)Rem. Sens. Environ. 58, 215-223(1996).

Skamarock, W. C., J. B. Klemp, J. Dudhia, D. O. Gill, D. M. Barker, W. Wang and J. G.Powers (2005). A Description of the Advanced Research WRF Version 2. NCAR TechnicalNote (available at http://wrf-model.org/wrfadmin/docs/arw_v2.pdf).

S.M. Adler-Golden, M.W. Matthew, L.S. Bernstein, R.Y. Levine, A. Berk, S.C. Richtsmeier,P.K. Acharya, G.P. Anderson, G. Felde, J. Gardner, M. Hoke, L.S. Jeong, B. Pukall, J. Mello,A. Ratkowski, and H.-H. Burke, Atmospheric Correction for Short-wave Spectral Imagery

based on MODTRAN4, SPIE Proceeding, Imaging Spectrometry V, Volume 3753 (1999).

A k l d


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AcknowledgemNASA NSERC

For the opportunity and for fullysupporting this research.

SARP StaffAlexandra, Barbara, Jane, John, Don, Shawn, Walter,David, Scott, Rick and George

For all your help and making thisexperience fun and educational!

MASTER Team especially Nick

For all the grunt work that we didnthave to do.

SARP students ...

Pa arriba, pa bajo, pal centro y pa

dentro Gracias!


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Questions"If we knew what it was we were doing, itwould not be called research, would it?"

Albert Einstein

lunacruz_atmospheric processing sarp presentation

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