National Polarorbiting Operational Environmental Satellite System NPOESS

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National Polar-orbiting Operational Environmental
Satellite System (NPOESS)
CrIMSS on NPP and NPOESS POLAR MAX 2006NOAA
Auditorium and Science CenterSilver Spring,
MDOctober 24-26, 2006Gail Bingham, SDLNPOESS
IPO IGS Team
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Topics

• Introduction
• Atmospheric soundingThe NPOESS CrIMSS System
• Advanced sounder system characteristics
• Sensors (CrIS, ATMS)
• CrIS Status and Performance
• SDR Algorithm Status and Testing
• ATMS Status and Performance
• ATMS Status and Performance
• ATMS Algorithm
• NPP Cal/Val Planning and Support Systems
• SPSR SIPS
• IPO SIPS
• SDS (PEATE)
• Conclusions

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The NPP / NPOESS Atmospheric Sounder Team
NGST
Raytheon
ATMS
Universities
Science Community
CrIS
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ATMS is combined with CrIS to satisfy NPOESS
Atmospheric Sounding EDRs
(CrIMSS ? Profiles of Temperature, Moisture, and
Pressure)
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CrIS Sensor Features

• Michelson Interferometer (FTS)
• Large 8 cm Clear Aperture
• Three Spectral Bands
• LWIR 650-1095 cm-1 (713 Chan _at_ 0.625)
• MWIR 1210-1750 cm-1 (433 Chan _at_ 1.25)
• SWIR 2155-2550 cm-1 (159 Chan _at_ 2.5)
• 1305 Total Spectral Channels
• 3x3 FOVs at 14 km Diameter for All Bands
• Photovoltaic Detectors in All 3 Bands
• Passive Detector System Cooler
• Plane-Mirror Interferometer With DAPS
• Internal Laser Wavelength Calibration
• Deep-Cavity Internal Calibration Target
• Passive Vibration Isolation System Allows
• Robust Operation in 50 mG Environment
• SDR Algorithm Verified During FM1 Testing

Volume lt 71 x 80 x 95 cm Mass lt 152 kg
Power lt 124 W Data Rate lt1.5 Mbps
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CrIS Measurement Bandpass Comparison

GIFTS
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Interferometer Measurements to Soundings
Michelson Interferometer (FTS)
Interferogram
Fixed Mirror
d1
Beam Splitter
Moving Mirror
Source
d2
(d2-d1)
Detector
Fourier Transformation
Numerical Inversion
Vertical Sounding
Radiance Spectrum
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CrIS vs. AIRS Noise Comparison
Testing to date shows CrIS has potential to
provide AIRS level performance
CrIS EDU 3 NEdN Was Measured in Thermal Vacuum
Testing At Mission Nominal Temperature To Verify
Performance
AIRS for 250K scene,CrIS for 303 K(SW NENs
similar for 300K scene)
AIRS
CrIS spec
NEdN (mW/(m2 sr cm-1)
CrIS FM1 will have improved SWIR and MWIR
Performance with Flight Detectors and Signal
Processors
CrIS
EDU 3 Data
Wavenumber (cm-1)
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Testing Designed to Verify Interfaces and
Performance
INTEGRATE

• EMI
• Conducted Emissions/Susceptibility
• Radiated Emissions/Susceptibility
• Transients
• Vibration
• Launch Loads
• Electrical Performance
• Power (Peak/Average)
• Servo Performance
• Radiometric Performance
• Dynamic Range
• Non-Linearity
• NEdN
• Uncertainty
• Repeatability
• Spatial Performance
• FOV Shape and Location
• Band-to-Band Shape Match
• Co-Registration

ICD Verification
FM1 Test Campaign

• Performance
• All Orbits (Temperature)
• Voltages 28 6 VDC

ICD Verification
SHIP
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SDR Algorithm Requirement Summary

• Perform Calibrations
• Radiometric (complex gain and offset)
• Wavelength calibration.(once per orbit)
• Spectral correction of ILS distortion
• Geo-location (FOV line of sight relative to
  spacecraft body)
• Remove Sensor Unique Signature
• Map spectra to fixed channel centers ..(all 9
  FOVs)
• Same spectral response shape for all channels
  within a band)
• Uncertainty (Sensor SDR algorithm)
• LWIR MWIR SWIR Relative to
• Radiometric gain 0.45 0.58 0.77 287 K BB
• Channel center 10 ppm 10 ppm 10 ppm wavenumber
• ILS width main lobe 1.5 1.5 1.5 true FWHM
• Geo-location 1.5 km 1.5 km 1.5 km

Functional Requirements
Quantitative Requirements

• SDR Algorithm is being used by ITT to process FM1
  acceptance test data
• Method will assure full maturity of ATBD and
  Science Code at NPP launch
• Test dataset will be developed to validate IDP
  SDR code

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SDR Algorithm Functional Flow
CrIS Sensor RDRs

• Prepare Interferogram Data
• CCSDS unpacking remove data compression (bit
  trim)
• Laser metrology calibration using neon reference
• Quality control tests (rejects bad data)
• Convert Interferograms to Spectra
• DFT
• Detect/correct metrology fringe count error
  (rare)
• Calibrate Radiance Scale
• ICT DS moving window average (2 point
  calibration reference)
• Calculate ICT radiance correct for environment
• Remove background offset phase dispersion
• Spectral Re-sampling Correction
• Apply post-calibration filter
• Resample FTS channel centers to EDR channel
  centers
• ILS correction
• Apply apodization (if selected)
• Compute LOS Relative to S/C Body Frame (each FOV)
• Format Output

RDR Pre-processing
DFT
Calibrate Radiance
Spectral Re-sampling Correction
Geo-locate Output
SDR Output
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SDR Code Verification Continues Using FM1 Data
Input Scenes
Actual CrIS FM1 Interferograms - All Detector
Positions
Calibrated Spectra as if from Center Detector
Position
Black Body
S

SDRAlgorithm
ErrorResiduals
CrIS Test Data
CO2 Laser
_
High Resolution Gas Cell Absorption Spectra
Scene Convolved with Ideal Sensor Response

• CrIS data sets will include
• Warm, cold and external BB target scenes
• Gas cell absorption spectra
• CO2 laser line spectra

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Example EDU3 SDR Algorithm Spectra in MWIR Band
After ILS Correction
Spectra from all 7 MWIR FOVs overlay well after
SDR algorithm correction
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CrIS Instrument Summary

• CrIS FM1 is in the environmental testing stage
• A few issues are being worked from EMI
• A significant test anomaly was encountered in
  VIBE
• Schedule impact of VIBE anomaly is still under
  investigation
• CrIS Pre-TV Test Readiness Review recently
  completed
• Bench performance testing indicates FM1 will
  exceed requirements
• CrIS SDR Algorithm being used to process FM1
  test data
• ATBD has been verified using EDU 3 and FM1 bench
  testing
• Errors in the Matlab Science Code (SC) have been
  identified and C SC code has been updated -
  being used on FM1 test data
• SC has been delivered to NGST and Raytheon for
  conversion to Operational Code
• Final performance of both instrument and SDR will
  be verified in the Thermal Vacuum testing

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ATMS Overview
ATMS Supersedes AMSU MHS

• NPP Flight unit has completed testing and is
  ready for integration
• 22-channels (23.8 GHz 183.3 GHz),
  functional-equivalent follow-on to AMSU-A, AMSU-B
  and MHS, with improved sampling and coverage
• Has a total-power, two-point external calibration
  system
• Provides continuous cross-track scanning, with
  torque momentum compensation
• Designed to support both NPP and NPOESS
  sun-synchronous orbits

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ATMS Scanning Characteristics

• 1.1 sampling interval
• Contiguous coverage at equator

(824 Km orbit, NPP)
105.45
BP 1
BP 48
17.6 km Scan spacing
BP 49
16.0 km
Sample interval
BP 96
Subsatellite track
Swath 2503 km
Y (Anti-Sun)
X (Velocity)
Cold Cal BP 97-100
Earth View BP 1-96
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Advanced Technology Microwave Sounder (ATMS)
22-channels (23.8 GHz 183.3 GHz),
functional-equivalent follow-on to AMSU-A and
MHS, with improved sampling and coverage
Adapted from David H. Staelin
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ATMS Test Performance

• PFM Qualification, Environmental and Calibration
  testing was completed in October 2005
• Met NEDT requirements for all 22 channels
• Met calibration accuracy requirements for all 22
  channels
• Met Beam width / Efficiency requirements for all
  channels
• Nonlinearity waiver has been granted for channel
  2
• EDU completed integrated tests with NPP
  spacecraft and was shipped back to NGES

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ATMS SDR Algorithm
ATMS Sensor RDRs
RDR Pre-processing

• Ingest Module
• Read input data, allocate to appropriate data
  structures
• Quality control tests (rejects bad data), Zero
  fill output
• Radiometric Calibration
• Utilize multi-scan averaging of calibration
  targets
• Apply calibration equation using warm load and
  cold space
• Correct for bias errors and non-linearity
• Compute beam position Scene Brightness
  Temperature
• Geolocation Processing
• Compute non-beam position dependent variables
• Compute beam position dependent variables
• Resample to CrIS Beam Centers
• Correct for beam size and ground track
  differences
• Utilize Backus-Gilbert filtering to reduce error
  amplification
• Format Output

Data Integrity
Calibrate Radiance
Geolocation Processing
SpatialRe-sampling to CrIS FOR
Reformat
SDR Output
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Re-sampling Requirement Description
ATMS makes three scans during each CrIS scan
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ATMS Summary

• NPP Protoflight Unit has completed testing and is
  waiting integration
• Antenna sidelobe interaction to be investigated
  on-orbit
• SDR Algorithm Code Accepted
• Basic principles follow AMSU and NAST-M
  development
• Re-sampling algorithm model tested
• Channel 2 non-linearity issue worked during
  Cal/Val
• NPOESS C1 ATMS is being procured as part of the
  NG contract.
• Gunn Diode Oscillator design funded by IPO and
  NASA

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CrIMSS EDR Algorithm Status

• CrIMSS EDR Algorithm is being coded by IDPS
• Initial testing of science version shows spec
  compliance
• Golden Day AIRS data set supplied by GFSC to
  allow direct comparison of AIRS and CrIMSS
  retrievals
• Plan to compare with IASI data when available
• CrIMSS is the third in the series of new
  sounders, so significant new real world
  understanding will be available before CrIS
  becomes operational
• The big challenge will be to have
  state-of-the-art Operational Code ready when NPP
  launches

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Cal/Val Effort Approach

• CrIMSS EDR will be a third generation code
• Removing instrument differences between grating
  and FTS instruments to provide accurate Spectral
  Radiance to user product codes is a well
  understood process
• The KEY Cal/Val effort will be removing
  instrument characteristics, with the SDRs, to
  provide globally validated radiances as soon as
  possible after launch
• Changing the Operational code will require
  control board review, prioritization and NGST
  implementation
• A flexible and accessible code verification and
  modification system is being established to speed
  the Cal/Val process

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Cal/Val Algorithm Evaluation Processing
CCB Review

• NSIPS
• NGST/Raytheon-managed, off-line copy of the
  operational process with intermediate product
  storage access
• Processes running in the operational environment
• GRAVITE (Government Resource for Algorithm
  Verification, Independent Test, and Evaluation
  Pronounced Gravity) Provided by NPOESS
  IPO-algorithms
• Science Data Segment (with product evaluation and
  analysis tool elements) Provided by NASA for
  climate data analysis

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Cal/Val Center Definitions

• NSIPS (Operational (4 IBM P-570 CPU environment)
• Supports SSPR and community Cal/Val teams
• Minimizes Cal/Val reliance on operation team,
  operational assets and operation support assets
• Cal/Val specific data distribution, validation
  data, support data processing and maintenance of
  baseline algorithms
• Runs Cal/Val modifications in operational
  environment
• GRAVITE (Operational Algorithms Linux
  environment)
• Provides Gov and IGS Science Team flexible
  processing and take home access to algorithms
  and data
• Provides affordable processing platform for
  distributed evaluation
• Demonstrated (Linux) improvements passed back to
  NSIPS for verification in operational environment
  then to CCB review
• NPP SDS (Prototype element for ES distributed
  data system)
• NPP Climate Data Record Science Team processing
  asset

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CrIMSS Summary

• CrIS instrument is in environmental test phase
• Significant vibration issue being worked
  schedule impact is uncertain at this point
• SDR algorithm being used for testing analysis
  mature
• ATMS instrument is in storage waiting
  integration
• NPOESS C1 LO replacement system in development
• SDR algorithm was validated by LL study
• CrIMSS EDR algorithm developers are aware of
  developments with AIRS and IASI science
• Cal/Val data processing systems are being
  developed to support pre-launch, post launch
  intensive Cal/Val and long term analysis