terra spacecraft - nasa · jorquera, c., c.j. bruegge, v.g. duval (1992). evaluation of high...
TRANSCRIPT
eter (MISR)am
ndation
Multi-angle Imaging SpectroRadiomCalibration and Test Progr
Carol J. BrueggeJet Propulsion Laboratory
California Institute of Technology
A presentation to the National Science FouNovember 4, 1998
Terra SpacecraftEOS MISR
MISR
l Investigator
d testpolarization, BRF
l data analysisl facility designting
chamberies
software
ACKNOWLEDGMENTS
David Diner MISR/ AirMISR PrincipaTerry Reilly Project ManagerValerie Duval Calibration EngineerCarlos Jorquera Photodiode assembly anNadine Chrien Radiometric model,
analysisBarbara Gaitley Radiometric and spectraGhobie Saghri Radiometric and spectraDaniel Preston Filters/ flight camera tesTeré Smith Integration and testEric Hochberg Optical CharacterizationRobert Korechoff MTF, focus, special studDavid Haner Spectralon BRF testingBrian Chafin In-flight data processing
MISR
ctral Polarizationdata fidelity
t video
OUTLINE
The MISR/ AirMISR instrumentsDetector-based calibration
Manufacture of the laboratory and flight standardsTraceability to Système International UnitsNIST verification (EOS round-robin experiment)
Test program"Optical Characterization Chamber": MTF, PSF, focus"Radiometric Characterization Chamber": Radiometric, SpeInstrument level tests: image verification, camera pointing,
Special studiesOut-of-band spectral response, focal-plane scattering, offse
In-flight calibrationOn-board calibrator, vicarious calibrationReconciling multiple calibrations
Data productsThe Ancillary Radiometric Product
MISR
T.P. Ackerman, R. Davies, S.A.W. Gerstl,). Multiangle Imaging SpectroRadiometer6, 1072-1087.
ia, M.A. Hernandez, C.G. Kurzweil, W.C.lti-angle SpectroRadiometer (AirMISR): 1339-1349.H.R. Gordon (1998). Techniques for thens. Geosci. Rem. Sens., Vol. 36, pp. 1212-
erg (1998). MISR prelaunch instrument. 1186-1198.mos. and Oceanic Tech., Vol.13 (2), 286-
Multi-angle Imaging SpectroRadiometer
ncertainties for the Multi-angle Imagingbserving System Platforms, Proc. SPIE
PUBLICATIONS LIST(SELECT PAPERS)
Complete publication list is available via the Internethttp://www-misr.jpl.nasa.gov ==> Publications
IEEE’98 EOS Special issueBruegge, et. al. See Calibration Overview.Diner, D.J., J.C. Beckert, T.H. Reilly, C.J. Bruegge, J.E. Conel, R. Kahn, J.V. Martonchik,
H.R. Gordon, J-P. Muller, R. Myneni, R.J. Sellers, B. Pinty, and M.M. Verstraete (1998(MISR) description and experiment overview. IEEE Trans. Geosci. Rem. Sens., Vol. 3
D.J. Diner, L.M. Barge, C.J. Bruegge, T.G. Chrien, J.E. Conel, M.L. Eastwood, J.D. GarcLedeboer, N.D. Pignatano, C.M. Sarture, and B.G. Smith (1998). The Airborne Muinstrument description and first results. IEEE Trans. Geosci. Rem. Sens., Vol. 36, pp.
Martonchik, J.V., D.J. Diner, R. Kahn, T.P. Ackerman, M.M. Verstraete, B. Pinty, andretrieval of aerosol properties over land and ocean using multi-angle imaging. IEEE Tra1227.
Calibration overviewBruegge, C.J., V.G. Duval, N.L. Chrien, R.P. Korechoff, B.J. Gaitley, and E.B. Hochb
calibration and characterization results. IEEE Trans. Geosci. Rem. Sens., Vol. 36, ppBruegge, C.J., D.J. Diner, and V.G. Duval (1996). The MISR calibration program. J. of At
299.Bruegge, C.J., V.G. Duval, N.L. Chrien, and D.J. Diner (1993). Calibration Plans for the
(MISR). Metrologia,30 (4), 213-221.Chrien, N.C.L., C.J. Bruegge, and B.R. Barkstrom (1993). Estimation of calibration u
SpectroRadiometer (MISR) via fidelity intervals. InSensor Systems for the Early Earth O1939, April, 114-125.
MISR
con photodiodes for calibration in the 4004.ter standards for NASA’s Earth Observing
otodiode standards for use in the MISR in-
ak, and M. Pavlov, "Initial results of thenference issue: New Developments and
s a diffuse reflectance standard for in-flight
amination analysis of Spectralon diffuse
, and M. Pavlov (1998). Intercomparison ofnsmissive materials, San Diego, 20-21 July.on’s bidirectional reflectance for in-flightn, and Processing of Remotely Sensed
Uncertainty Tabulations for the Retrievalin Optical Radiometry (NEWRAD ’97),
PUBLICATIONS, CONT.
PhotodiodesJorquera, C., C.J. Bruegge, V.G. Duval (1992). Evaluation of high quantum efficiency sili
nm to 900 nm spectral region. In Infrared Technology XVIII. Proc. SPIE 1762, 135-14Jorquera, C.R., V.G. Ford, V.G. Duval, and C.J. Bruegge (1995). State of the art radiome
System. Aerospace Applications Conference, 5-10Feb, Snowmass, CO.Jorquera, C.R., R. Korde, V.G. Ford, V.G. Duval, C.J. Bruegge (1994). Design of new ph
flight calibrator. IGARSS ’94, 8-12Aug, Pasadena, Ca.
Diffuse panel studiesT. R. O'Brian, E. A. Early, B. C. Johnson, J. J. Butler, C. J. Bruegge, S. Biggar, P. Spy
bidirectional reflectance characterization round-robin in support of EOS AM-1," CoApplications in Optical Radiometry (NEWRAD ’97), Metrologia, in preparation.
Bruegge, C.J., A.E. Stiegman, R.A. Rainen, A.W. Springsteen (1993). Use of Spectralon acalibration of earth-orbiting sensors. Opt. Eng.32(4), 805-814.
Stiegman,A.E., C.J. Bruegge, A.W. Springsteen (1993). Ultraviolet stability and contreflectance material. Opt. Eng.32(4), 799-804.
Barnes, P.Y., E.A. Early, B. Johnson, J.J. Butler, C.J. Bruegge, S.F. Biggar, P.R. Spyakreflectance measurements. In SPIE 3425, Optical Diagnostic methods for inorganic tra
Flasse, S.P., M.M. Verstraete, B. Pinty, and C.J. Bruegge (1993). Modeling Spectralcalibration of Earth-orbiting sensors. In Recent Advances inSensors, Radiometric CalibratioData, Proc. SPIE1938, April, 100-108.
In-flight calibrationC.J. Bruegge, N. L. Chrien, R. A. Kahn, J. V. Martonchik, David Diner (1998). Radiometric
of MISR Aerosol Products. Conference issue: New Developments and ApplicationsMetrologia..
MISRulti-angle Imaging SpectroRadiometer. In
g SpectroRadiometer (MISR)," inEarth
ance testing of the Multi-angle Imagingly, 23-26 September 1996.elopment and test status. InAdvanced andptember.ntical Spectroscopic Techniques andust.f MISR lenses and cameras. InOpticalPIE, VOL. 2830 Denver, CO, 5-9
eration Satellites. Spectroradiometer focal-TO/ SPIE Vol. 2538, pp. 104-116, 25-28
calibration of the MISR linear detectors.
the Earth Observing System Multi-angle Nebraska, 27-31 May.
PUBLICATIONS, CONT.
Chrien, N.L. and C.J. Bruegge (1996). Out-of-band spectral correction algorithm for the MEarth Observing System. Proc. SPIE2820, Denver, Co, 5-9 August.
Testing reportsC.J. Bruegge and D.J. Diner, "Instrument verification tests on the Multi-angle Imagin
Observing Systems II, SPIE3117, San Diego, CA, 28-29 July 1997.Bruegge, C.J., N.L. Chrien, B.J. Gaitley, and R.P. Korechoff (1996). Preflight perform
SpectroRadiometer cameras. In Satellite Remote Sensing III, Proc. SPIE2957, Taormina, ItaBruegge, C.J., V.G. Duval, N.L. Chrien, and R. P. Korechoff (1995). MISR instrument dev
Next-Generation Satellites. Proc. EUROPTO/ SPIE2538, 92-103, Paris, France, 25-28 SeHochberg, E.B., and N.C. L. Chrien (1996). Lloyds mirror for MTF testing of MISR CCD. IOp
Instrumentation for Atmospheric SpaceResearch II. Proc. SPIE2830, Denver, CO, 5-9 AugHochberg, E.B., M.L. White, R.P. Korechoff, C.A. Sepulveda (1996). Optical testing o
Spectroscopic Techniques and Instrumentation for Atmospheric SpaceResearchII. Proc. SAugust.
Korechoff, R.P, D.J. Diner, D.J. Preston, C.J. Bruegge (1995). In Advanced and Next-Genplane design considerations: lessons learned from MISR camera testing. EUROPSeptember.
Korechoff, R., D. Kirby, E. Hochberg, C. Sepulveda, and V. Jovanovic (1996). DistortionIn Earth Observing System. Proc. SPIE2820, Denver, Co, 5-9 August.
IFRCC/ Level 1B1Bruegge, C.J., R.M. Woodhouse, D.J. Diner (1996). In-flight radiometric calibration plans for
Imaging SpectroRadiometer. IEEE/IGARSS, Paper No. 96.1028, Lincoln,
MISR
may cause a delay MOPITT
MISR OVERVIEW
Platform: Terra (EOS-AM1)Launch: No earlier than August 27, 1999
- recent TITAN IV/CENTAUR and DELTA III launch failures Other EOS-AM1 instruments: MODIS, CERES, ASTER, and
MISR capabilities: Multi-angle global view of earth- 9 cameras pointing nadir to ±70°- 4 spectral bands 446, 558, 672, and 866 nm- global coverage every 9 days- on-board pixel averaging (275 m - 1.1 km)- average data rate 3.3 Mb/sec
AEROSOLS SURFACE
CLOUDS
MISR
MISR
EARTH-VIEW GEOMETRY
MISR
198819933, 1993ry 10, 1994er 6, 1994 27-28, 1995
t 1994-August 1995t 1995-August 1996r 1996
1997
98
DEVELOPMENT TIMELINE
• Proposal submitted July 15,• Preliminary design review (PDR) May 25,
- Calibration peer review May 2- Preflight calibration plans Janua
• Critical design review (CDR) Decemb- Calibration peer review II March
• Calibrate cameras- Engineering model Augus- Calibrate flight cameras (10) Augus
• Instrument thermal vacuum testing Decembe• MISR arrives at spacecraft integrator May 26, • Develop in-flight calibration processing 1998
capability• Original launch date June 19
MISR
s submitted toNov 1995
MISR productsonalibrated multi-angle
s (room reserved ineras)
mbaled to nine view-
esign, shortest focal
0 - 40 nm)response measuredres
AIRMISRINSTRUMENT HERITAGE
• Original proposal “Low-cost Airborne MISR Simulator” wathe EOS Project Scientist (Dr. Michael King, GSFC) on 10
• Objectives for AirMISR- collect MISR-like data sets in support of the validation of - underfly EOS-AM1 MISR to verify its radiometric calibrati- enable scientific research utilizing high quality, well-c
imaging data- enable the exploration of measurement enhancement
instrument reserved as technology testbed for future cam• MISR inheritance
- implementation features a single pushbroom camera, giangle positions during a 15 minute data acquisition run
- camera comprised of a MISR brassboard lens (“A” lens dlength), and MISR engineering model focal plane
- spectral bands at 446, 558, 672, and 866 nm (widths of 2- spectral, radiometric, and point-spread-function (PSF)
using MISR-developed laboratories and analysis procedu
MISR
Da-70.5
DATA ACQUISITION
Df/ Da
Cf/ Ca
9.0
km
11.4 km
34.2 km
Bf/ Ba
Af/ AaAn
Ca-60.0
Ba-45.6
Aa-26.1
An0.0
Df
Cf
Bf Af
26.5
km
MISRN
40)
e
ngixels
PERFORMANCE COMPARISO
Parameter MISR AirMISR
Absoluteuncertainty
3% (1σ) 3% (1σ)
Number ofdetectorelements
9 camera x 4bands x 1504pixels (~53,000)
4 bands x 150pixels (~600
Worst detectorelements
10% < responseloss < 1%
40%< responsloss
Number ofdetectoranomalies
~12 ~20 in blue~ 20 in green
SNR > 900 same, excludianomalour p
Spectral out-of-band
<2% 4% in Band 3
MISR
Preflight:
In-flight:
laboratory standardsprovide measure ofintegrating sphere output
flight standardsprovide measure ofdiffuser-reflectedsunlight
tandards establishto ±3% (1σ; ρeq=1.0)
t reflects bestment responsivity
DAAC
Level 1B productproduction using
recent ARP
Level 2science products
s
CALIBRATION PLAN
• Detector-based sradiometric scale uncertainty
Mission duration
Det
ecto
r re
spon
se
◊
+++++
◊◊++
++ +++ + + +
++ +
+
◊ Overflight campaigns(semi-annual)
+ On-Board Calibrator(monthly)
• Multiple methodologies reducesystematic errors
• System design:- temporal stability achieved through
radiation resistant components,contamination control, and flightUV blockers , lens shades, and cover
- polarization insensitivity achievedthrough optical design
- stray-light control within camerascalibrator subsystems
• Radiance producestimate of instru
MISR teamgeneration ofradiometriccoefficients
SCF
Monthly updateto ARP
MISRIC
0%ge detection
t signal ρeq=100%
signal ρeq=100%between calibrations
cy (HQE) and
MISR REQUIRES RADIOMETRCALIBRATION AND STABILITY
SCIENCE REQUIREMENTS (68% CONFIDENCE)
• Absolute radiometric uncertainty: ±3% at signal ρeq=10- Required for accurate albedo and aerosol retrievals, chan
• Relative angle-to-angle radiometric uncertainty: ±1% a- Required for accurate determination of angular signatures
• Stability (maximum change): 0.5%/ 1 month; 2%/ 1 year at- Required to maintain radiometric accuracy during intervals
RAMIFICATIONS FOR INSTRUMENT
• High accuracy on-board calibrator
• Detector-based calibration using high quantum efficienradiation resistant (PIN architecture) diodes
• High stability detectors, filters, and lenses
• Polarization insensitivity
• High signal-to-noise ratio
MISR
h out-of-band
logy) to avoid
er absorption
ument
MISR REQUIRES SPECTRALUNIFORMITY AND STABILITY
RAMIFICATIONS FOR INSTRUMENT
• Interference filter and blocker designs to provide higrejection
• High stability filter coatings (Ion Assisted Deposition technoneed for on-board spectral calibrator
• Gaussian band profiles to provide polarization insensitivity
REQUIREMENT RATIONALE
Accuracy - Optimizes science- Avoids solar Fraunhofer lines and atmospheric wat- Provides synergism with other instruments
Knowledge - Necessary to avoid radiometric error
Uniformity - Minimizes complexity of science algorithms- Achieves consistent retrieval across the scene
Stability - Eliminates need for on-board calibration within instr- Achieves consistent retrieval with time
MISRN
very lax calibration
ation requirements
etectors
bility (protected from
y techniques (1 µm
tindependent devices
DETECTOR-BASED CALIBRATIO
• MISR has stringent calibration requirements- Remote sensing systems flown prior to 1990 had
requirements- Landsat program did not provide radiance data products- SPOT requires absolute calibration to only 10%- Conversely, MISR has very stringent (3%) absolute calibr- Detector-based calibration elected to meet this challenge- Literature reports accuracies of 0.5%, using filtered trap d
• Building flight detectors no easy task- assembly hermetically sealed to allow focal plane sta
humidity, contaminants, filter shifts)- light-trap manufactured from using ceramic subcarriers- precision apertures manufactured using photolithograph
tolerance)- radiation testing required, simulating on-orbit environmen- radiometric response verified by consistency checks with
(laboratory standards and wedge standards)
MISR
An
Ca
Cf
AaBa
Af
Bf
HQE1-4
N-PIN
Da-PIN
Df-PIN
G-PIN
ON-BOARD CALIBRATOR
Da
Df
An
Aa
Ba
Ca
Af
Bf
Cf
Df
67.5°
Stoweddiffuse panel
Deployeddiffuse panel
Da
MISR
E
Es)
camera view anglesdation permissable)
)
lysis considering the
IN-FLIGHT RADIOMETRICCALIBRATION
On-Board Calibrator (OBC)
• High quantum efficiency (HQE) diodes- Detector-based radiometric standard for the instrument- Configured in light-trap arrangement to give near 100% Q
• Radiation resistant PIN diodes- Secondary detector standard (longer lifetime than the HQ
• Deployable Spectralon diffuse panels- Relative BRF needed to transfer diode measurements into- Absolute reflectance knowledge unnecessary (slow degra
• Mechanized goniometer diode (G-PIN)- Verifies BRF stability of diffuse panels
Radiometric calibration- Acquire monthly OBC data (6 minute interval at each pole- Conduct semi-annual overflight field campaigns- Calibration coefficients computed from a time trend ana
preflight, OBC, and overflight measurements
MISR
luminum tray between
owth without distortion
y will be customized if
n to be wiped with 200
in dry nitrogen purgedmples. Spectralon will
48 hours.
SPECTRALON DESIGN
Panel design- Panel difficult to frame, as Spectralon grows 0.29” beyond a
survival temperatures -65 to 80°C.- Panel design has feet protruding into frame to allow thermal gr
and survive launch loads without yielding (yields at 200 psi).- Spectralon can only be machined to a tolerance of 0.005”. Tra
necessary upon Spectralon delivery.Handling specifications
- During manufacture all surfaces to contact resin or Spectraloproof reagent grade Ethyl Alcohol.
- During transport within Labsphere or to JPL material storedaluminum transportation container with 9 integral witness sabe housed in EM or PF container for BRDF testing.
- Following machining material baked out at 10-6 torr, 90°C for
2.8”
0.28”
20.55”
MISR
ose
n versus discharge damage (done)
edures (done)tries
)ned)
articulate contamination
SPECTRALONFLIGHT QUALIFICATION
Test Purp
Charge arcing evaluation Frame/ housing configuratio
Process verification tests Cleaning and handling procBRDF study at in-orbit geomePolarizationSolar absorptance/ emittance
Environmental exposure testsBRDF data will be acquired before and after to
evaluate stability
UV/ vacuum (repeat)HumidityThermal vacuum cyclingCharged particle, proton (doneAtomic oxygen (analyses plan
Mechanical and physical property testing Tension strengthCompression strengthModulusDeformation under loadFlexural
Vibration testing Launch vibration loads with pevaluation
MISRSPECTRALON
HEMISPHERIC BRF
MISR
Earth(day side)
e)
nator
lightirection
IN-FLIGHT CALIBRATION:MISSION PLAN
North pole deploy
Night calibration
Sunrise (on panel)
Goniometer
Clear atmosphere
Panel stow
(1.0 min)
(1 min)
(1.3 min)
(2 min)
(3.3 min)
(0.25 min)
Earth(night sid
Termi
Fd
• North Pole: panel deployed for aftand nadir camera calibration
• One minute of night calibration• Varying irradiance at sunrise• Clear atmosphere interval is
uncontaminated by Earthatmos (200 km solar tangent)
• Window end whenDf data collectionbegins
MISR
on
EOS CALIBRATION PANEL
• Membership- EOS project office lead- NIST representatives (Carol Johnson, Joe Rice)- Calibration scientist for each of 5 instrument teams- Calibration specialists:
Vicarious calibration, Phil Slater, Univ. of ArizonaLunar studies, Hugh Kieffer, US Geological Survey
• Workshops (1 or 2 times a year)• Peer reviews (2 reviews per instrument)• Round-robin experiments
- Radiometric (integrating sphere output verification)- Diffuse panel bi-directional reflectance function comparis
MISR
tion must be NIST
to standards held at
e International (SI)urrent, voltage, and
ll understood in the
n to NIST-traceablerobin experiments
TRACEABILITY
- EOS contractual agreement reads that MISR calibratraceable
- In-house design does not come with a pedigree traceableNIST
- MISR detector standards are traceable to the Systèmradiance scale via traceable protocols of measuring cdistances
- The internal quantum efficiency of these devices is weliterature
- Verifications of our scale were provided by comparisolamps, and participation in EOS/ NIST sponsored round-
MISR
ting sphere output.lute requirement.l
ral instruments.MISRds.
line
AUGUST 1994ROUND ROBIN
• Various transfer radiometers compared MISR integraResults give confidence in ability to achieve 3%(1σ) abso
• Additionally, filter transmittance was measured by seveCary establishes radiometric scale of Laboratory Standar
Wavelength (nm)
Radiometer 550 650 666
MISR 0.4%
UofA -1.% -0.8%
NRLM 0.9%
Wavelength (nm)
Filter λc, 500 687 748
MISR Cary baseline baseline base
JPL Beckman +1.3% -0.1% -1.7%
UofA Optronics +5.0% +11.0%
GSFC Perkins andElmer
+1.2%
MISR
AUGUST 1996ROUND ROBIN
MISRNTSM
NIST VS JPL BRDF MEASUREMESPECTRALON SAMPLE, 632.8 N
MISR
Thermal vacuumcalibration
Systemverification &shipping tests
Calibrationverification
eat for 9 cameras
peat for EM, protoflight
PREFLIGHT CALIBRATIONTEST FLOW
Subsystem verifications
Optics
Cameraelectronics
Mechanisms
Analogelectronics
Structures
Command &Data
Cameraassembly
Cameraverifications
Assembly levelverifications
Calibrate plate/
Diode/ goniometerassembly
mechanismsassembly
Nine camera/optics bench
assembly
Flight
RadiometricmodelComponent
parameters
qualificationtesting
Rep
Re
MISR
YUIOPL
BNM,.
cterization Chambere, monochromator spectral calibration,cation
HIGH BAY FACILITY
QWERTYUIOPASDFGHJKL
ZXCVBNM,.QWERT
ASDFGHJK
ZXCV
50x100 ft layoutx 30 ft heightClass 10,000 cleanroom
Optical Characterization ChamberFeatures: Pinhole target, camera gimbalTests: EFT. MTF, PSF, Distortion, saturation
Radiometric CharaFeatures: 1.65 m spherTests: Radiometric and
polarization verifi
Ground Support Equiment room
MISR
Vacuumchamber
Camera
GSE &sphere controller
RADIOMETRIC CALIBRATIONFACILITY
Powersupplies
• 65” Sphere• 30 x 9” Exit port
QWERTYUIOPASDFGHJKL
ZXCVBNM,.
• 12” externalsphere withvariable aperture
• 4’ working distance
MISR
ident radiance
are linear, except at
atic
iances and quadratic, upon completion of
, averaged over bothW m-2 sr-1 µm-1]:
amera output digitalients; DNo is the DNaverage over the first
MISR CALIBRATION EQUATION
• MISR will be calibrated in-flight by a regression of incagainst output DN.- Preflight data analysis has shown that the cameras
extremely low inputs (scene reflectance < 5%).- The use of a linear or non-linear equation, e.g. the quadr
has been investigated. This equation is linear at high radat small radiances. This latter equation will be baselinedthe current study.
- Lλ is the sensor band-averaged spectral incident radiancein-and-out-of-band wavelengths and reported in units of [
- R is the relative pixel spectral response; DN is the cnumber; G0, G1, and G2 are the pixel response coefficoffset, unique for each line of data, as determined by aneight "overclock" pixel elements.
DN DNo– Go G1L λ G2L λ2
+ +=
L λLsource∫ ℜλ λd
ℜλ λd∫-----------------------------------=
MISR:
RADIOMETRIC CALIBRATIONCAMERA OUTPUT DN
MISR
MEASURED CAMERA SNR
MISR
MEASURED CAMERASATURATION LEVELS
MISR
ONSE PROFILE:
resolution, 0.5 nmositionm resolution, 5 nmositionsludes focal-plane100 nm, and Codeo 400 nm.
0 to 900 nm
NG:f an integratingromator exit slit.y of illumination from several nm to
nm.
SPECTRAL CALIBRATION
Monochromator
Order SortingFilters
Optical Rail
Thermal-VacuumChamber
Baffle
Dark Tent
TOP VIEW
Chamber window
Xenon
Grating
CameraSupport
Electronics
Camera
COMPOSITE RESP
Integratingsphere
• In-band at 2.6 nm sampling, 7 field p
• Out-band at 19.5 nsampling, 3 field p
• Spectral model insmeasurements to 1V lens model 365 t
• Measured data 40
IMPROVED TESTI• Obtained by use o
sphere at monochSpectral uniformitimproved reducedseveral tenths of
MISR
to cover 10 -4
365 nm to 1100
00 nm)ntegration time (while
measurements
SPECTRAL RESPONSEFUNCTION DETERMINATION
• Separate in- and out-band measurements allowed ussensitivity range
• In-band spectral response measurements:- 400 to 900 nm wavelength range- 2.6 nm spectral resolution- 0.5 nm sampling
• Out-band spectral response measurements:- 400 to 900 nm wavelength range- 19.6 nm spectral resolution- 10 nm sampling
• Radiometric model utliized to extend response region fromnm.- lens model using CODE V at 5 field positions.- focal plane measurements of quantum efficiency (350-11- analog-to-digital gain using camera response to varying i
viewing the integrating sphere)• Both measured and band-averaged spectral response
published within the ARP
MISR
MEASURED SPECTRALPARAMETERS
MISR
en successfully analysis
rtion, PSF), RCC, hot and cold
the missionight failures noteddful of pixels. Only 8rmity exceeding 10%ented camerauccessful test
lowing ground
when needed. No
51 pixels PSF, 20
y.entify affected pixels.
SUMMARY
• MISR testing of 10 cameras (9 flight and 1 spare) has becompleted after 1 year development and 1 year testing and
• 6 weeks per camera required to provide OCC (EFL, disto(radiometric, spectral calibration, polarization verification)margin, dynamics, and magnetics testing.
• Several verification failures appear to have little impact on - swath overlap meets requirements, though camera bores- response uniformity meets requirement for all but a han
pixel zones (4 pixel block) out of 13,536 have a local unifo• Several verification failures result from unprecend
specifications, driven by 3 % radiometric requirement. Sprogram allows mission objectives to be met, folprocessing- out-of-band errors can be reduced from 4% to 0.5%
correction necessary for Band 1, or bright targets- PSF deconvolution requires minimal processing: 1D,
iterations (no FFT required)• Saturation appears to affect many pixels within the line arra
- Saturation unlikely on orbit. Data Quality Indicators will id
MISRRMS
Status
er Fixed
etween Fixed
eld toge
Fixed
filter Improved flightperformance
ion in Improved flightperformance
ature Fixed
d and New designbreadboarded
g or Options beinginvestigated
EM CAMERAS INVALUABLE FODIAGNOSING / FIXING PROBLE
Problem Cause Solution
White light leaks in filter Bondlines between bands Masks added to filt
Interference fringes in flat-field data
Fabry-Perot interferencebetween CCD and filter
Increase spacing bfilter and CCD
Spurious signal in CCD Illumination of siliconaround CCD bond pads
Addition of light shifocal plane packa
Insufficient out-of-bandrejection
Spattering in filter coatings Higher quality flightSpatter side down
Low-level “halo” aroundpoint-source image
Reflection between CCDand filter
See above. Correctdata processing ifneeded
Excess power needed tocool CCD to -10°C
Thermal leaks Focal plane temperchanged to -5°C
Complex assemblyprocedure to achieverepeatable focus
Lens to camera headinterface flanges
Interface redesignesimplified
Low-level inter-bandelectrical crosstalk(0.07%)
Suspected inadequategrounding
Additional groundincorrection in dataprocessing
MISR
SATURATION BLOOMING
MISR
to be cause of
95). In Advanced andfocal-plane designng. EUROPTO/ SPIE
FOCAL PLANE SCATTERING
• Filter scatter sites and CCD/ filter reflections determinedfinite width PSF and out-of-band performance, see:- Korechoff, R.P, D.J. Diner, D.J. Preston, C.J. Bruegge (19
Next-Generation Satellites. Spectroradiometerconsiderations: lessons learned from MISR camera testiVol. 2538, pp. 104-116, 25-28 September.
MISR
CCD
Filter
Window
Lens
d budget
ast target budget and
FOCAL PLANE SCATTERING
Spectral cross-talk
Ghost imagery
80% reflectivealuminum mask
25% reflectivemask (topand bottom)
Component of 1% out-of-ban
Component of 2% delta contrMTF specification
MISRSrder to assess
shes an absolute andolar-reflecting diffuser to verify there is no
monthly.
tive-calibration of the
into the coefficient less with time.der to achieve
MULTIPLE IN-FLIGHTCALIBRATION METHODOLOGIE
• MISR will make use of four calibration methodologies, in ocalibration uncertainty and reduce systematic errors.- On-Board Calibrator (OBC) hardware are used to establi
relative calibration for each pixel. The OBC consists of spanels (Spectralon), detector standards, and a goniometedegradation in the reflectance shape. Data are acquired
- Vicarious calibration (VC) can be one of three types:1) High-altitude sensor (e.g. AirMISR) VC2) Surface-radiance VC3) Surface reflectance VC
- Histogram equalization statistics are used to provide a relapixels within an array.
- Trend analysis are used to fold other calibration dataalgorithm (e.g. preflight). Retrospective data are weighted
• A weighting algorithm will combine the multiple data in orthe most accurate sensor calibration.
MISR
TRACEABILITY
QUALITY ASSES.
LEV. 1B1 RAD.PROD. VALIDTN• Sensor cross-comp.• Desert scenes• Lunar observ.
CALIBRATION INTEGRITY
DATA
SCENE RAD.ERRORS
NOISE STUDIES
• Contrast target• Spectral content
• Polarization
ANOMOLIES
• Pixel non-uniform.
CHARACTERIZATION
LEGEND
Other Input oractivity Output
IFRCC PROGRAM ELEMENTS
LEVEL 1AACQUIRE MISRCALIBRATIONMODE DATA
ACQUIRE MISRLOCAL MODE
DATAARP
• Radiometric calib.
MISR PREFLGTRADIOMETRICCALIBRATION
SCENE STUDIES• PSF• Spectral in-band
RAD. SCALINGALGORITHM
RADIANCECONDITIONING
ALGORITHM
coefficients and
• SNR• Pixel nonunif.
• Spectral param.
uncertainties
• PSF
UPDATED PARAMS.
STATIC PARAMS.
• Fields-of-view
LEVEL 1B1 ALGORITHMS
MISSION OPS
PREFLIGHT
IN-FLGT RAD.CALIBRATION
CAL TREND
HISTOGRAM EQ
VICARIOUS CAL.
OBCWEIGHT
scaling
• Quality thresholds
IFRCCactivity
MISR
arameters
ctions (7x36),ons (1 per band),
1B1 and Level 2
preflight
librationnd Detector Data
ntrol limits used
ARP STRUCTURES
File name Description
PreflightCharacterization Data
• preflight instrument characterization p• unlikely to be modified once delivered• measured pixel spectral response fun
standardized spectral response functiinstantaneous fields-of-view
Preflight Calibration Data • input to DAAC processes• unlikely to be modified once delivered• spectral descriptors relevant to Level
standard products• band weighted solar irradiances
In-flight Calibration Data • parameters updated monthly on-orbit• at-launch values are initialized by the
calibration data• radiometric calibration coefficients, ca
uncertainties, signal-to-noise ratios, aQuality Indicators.
Configuration Parameters • threshold parameters and process coby DAAC processes
MISR
ncident radiancesry pixel
weighted less)rds (HQE, PIN nadir,
oefficients, in case of
ultiple determinations
certainty
ARPGEN PROCESSING CODE
• Data conditioning- Resamples photodiode data to CCD data time acquisition- Removes corrupt data
• Regression- Regresses CCD DN data against photodiode measured i- Quadratic fit produces G0, G1, and G2 coefficients for eve- Data weighted inversely by the DN variances (noisy data- Process repeated using 3 independent on-board standa
PIN at closest view angle to camera being calibrated)• Coefficient trending
- Uses historical coefficients and present coefficient- Performs a quadratic fit to the data- Reported coefficient comes from fit. This smooths gain c
noise in the retrieval• Coefficient weighting
- Final coefficients come from a weighted average of the m(vicarious and 3 detector standards)
- Weighting is inversely proportional to the methodology un
MISR
iode radiancesal variances
detector data quality
ARPGEN PROCESSING(CONT.)
• Performance summary- SNR computed from residuals of CCD DN against photod- sliding window does local fit of the data, to determine loc- SNR used to update radiometric uncertainty tables- CCD element response uniformity updated as part of
metric
MISR
Level 1B1(MIS02)
physical parameters
mevel 2oducts
Image enhancement viaPSF deconvolution
RADIOMETRIC SCALINGAND CONDITIONING
Radiance Radianceconditioningscaling
Instrument DNs Radiance (W m -2 µm-1 sr -1)
Resampling and projection toSpace Oblique Mercator
grid
Geo-rectified and registeredradiances
Level 1A
Level 1B2
(MIS01)
(MIS03)
Out-bandcorrection
Geo
soLepr
MISRUCT
ve a band-averaged
ating for focal-plane
mments
ally-scaled dataic resampling
4 bands reported in Ancillary Product
spec.); 1 (reduced accu-usable for science);)
LEVEL 1B1 RADIOMETRIC PROD
RADIANCE SCALING
- Radiometric calibration coefficients are used to retriespectral radiance. Total-band response is included.
RADIANCE CONDITIONING
- PSF deconvolution to sharpen the image, compensscattering;
- A standardized spectral response function is assumed.
Parametername
UnitsHorizontal
Sampling (Coverage)Co
Radiance W m-2 µm-1
sr-1250 m nadir, 275 m off-
nadir, or averages per thecamera configuration(Global)
• Radiometric• No geometr• 9 cameras,• Uncertainty
Radiometric
Data Qual.Indicator
None Same as above • 0 (withinracy), 2 (un3(unusable
MISR
1B pixel. These
at. in red band)
tric errortric error; else DQI =2
)tric error
tric error; else DQI=2
evel 1B2 resampleweighting
ull
alf
one
one
DATA QUALITY INDICATORS(DQI)
• Data Quality Indicators (DQI) are assigned to each Levelare assigned the values:
• Saturation blooming (Note: in average mode pixel is sat. if s- DQI=0 if no. saturated pixels (nsat)=0- else DQI=1 if specific pixel under test has < 0.5% radiome- else DQI=1 if specific pixel under test has < 3.0% radiome
• Video offset uncertainty- DQI=0 if line average DN less than threshold (~12,000 DN- else DQI=1 if specific pixel under test has < 0.5% radiome- else DQI=1 if specific pixel under test has < 0.5% radiome
DQIvalue
significanceError component
radiance uncertaintycontribution
L
0 within specification None f
1 reduced accuracy 1-3% h
2 unusable for science 3-50% n
3 unusable >50% n
MISR
DQIlue
lse
lse
lse
DATA QUALITY INDICATORS(DQI), CONT.
• Detector anomaly- Values can be predetermined and stored in ARP- SNR used as DQI criteria
- Detector response uniformity used as DQI criteria
SNR DDQI value
>100 0, else
>90 1, else
> 10 2, else
3
Uniformity,4x4 average
mode
DDQIvalue
Uniformity,2x2 average
mode
Dva
<10% 0, else <10% 0, e
<15% 1, else <15% 1, e
<50% 2, else <50% 2, e
3 3