the imager/sounder paradigm revisited third goes-r users conference
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The Imager/Sounder Paradigm Revisited Third GOES-R Users Conference Broomfield, Colorado May 11 th , 2004 Joe Criscione, Jim Bremer, and Donald Chu Swales Aerospace. Outline. Examine Benefits of GEO Use GEO’s Assets as Paradigm Flow Instrument Architecture to Distributed Architecture - PowerPoint PPT PresentationTRANSCRIPT
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The Imager/Sounder Paradigm Revisited
Third GOES-R Users ConferenceBroomfield, Colorado
May 11th, 2004
Joe Criscione, Jim Bremer, and Donald ChuSwales Aerospace
Joe Criscione 301-286-00702
Outline
• Examine Benefits of GEO
• Use GEO’s Assets as Paradigm
• Flow Instrument Architecture to Distributed Architecture
• Assess Impact to Requirements– Order of magnitude increase in Severe/Weather Mesoscale Sounding– Order of magnitude increase in Coastal Waters Imaging– Sacrifices CO2 spectral resolution in Full Disk Sounding
• Examine Feasibility and a Concept of Operations
Joe Criscione 301-286-00703
How to Exploit GEO
• High temporal sampling of Full-Disk
– ABI images full disk every 5 minutes– All images from same point of view– Excellent way to observe change/flux
• Intense sampling of Region-of-Interest
– Can observe any point at any time– Ideal for observing rare/important
events• Coastal Waters, Severe Weather,
Natural and Man-Made Disasters
Joe Criscione 301-286-00704
Use GEO’s Assets as Paradigm
Current Architecture
• Imager (ABI)– 2D products– Full disk/CONUS/Mesoscale
• Sounder (HES)– 3D products (and coastal waters)– Full disk/CONUS/Mesoscale
Proposed Architecture
• Full-Disk (ABI+)– 2D and 3D products– Full Disk
• Region-of-Interest (HES+/-)– 2D and 3D products– CONUS/Mesoscale
Flow Instrument Architecture To Spacecraft
Distributed Architecture
• Full-Disk S/C– Points at Nadir– ABI+ Scans Full Disk– Carries other payloads that
require a Nadir deck (GRB, GLM, etc. )
• Region-of-Interest S/C– Satellite points at target and
HES+/- Collects data WITHOUT SCANNING
• Scanner dominates radiometric and pointing error budgets
• Reduces Field of Regard by order of magnitude
• Can double aperture for HES+/-
Joe Criscione 301-286-00705
What’s Changed?
Imager(ABI)
Sounder(HES)
30cm Aperture2-axis Scanner
30cm Aperture2-axis Scanner
Nadir Pointing Bus
Nadir Pointing Bus
Full-DiskImaging
• 5 min revisit• 0.5 km VIS• 2.0 km IR• 300:1 SNR• 0.1K NEDT•16 channels
MesoscaleSounding
• 4 min meso • 1 hr CONUS• 4km GSD• 64% DOEE• 1.0 cm-1• 0.1K NEDT
Full-DiskSounding
• 1 hr revisit• 10km GSD• 90% DOEE• 1.0 cm-1• 0.1K NEDT
CoastalWaters
• 3 hr revisit• 250m GSD• 300:1 SNR
Proposed ArchitectureFull-Disk
(ABI+)Region-Of-Interest
(HES+/-)
30cm Aperture2-axis Scanner
Nadir Pointing Bus
Full-DiskImaging
• 5 min revisit• 0.5 km VIS• 2.0 km IR• 300:1 SNR• 0.1K NEDT• 16 channels
NEDT: Noise Equivalent Delta TemperatureGSD: Ground Sample DistanceDOEE: Detector/Optics Ensquared Energycm-1: Spectral Channel Width in wavenumber
Flow InstrumentArchitecture to
S/C Architecture
Eliminate Scanner& Double Aperture
60 cm ApertureNo Scanner
Target Pointing Bus
Current Architecture
Full-DiskSounding
• 5 min revisit• 10km GSD• 90% DOEE• 3 cm-1 H2O• 10 cm-1 CO2
• 0.5K NEDT• Could do 4km GSD at expense of NEDT & DOEE• Concurrently with Imaging (NOT time shared)
Move Full-Disk Sounding to ABI
Trade Spectral Resolutionand NEDT for Revisit Time in Full-Disk Sounding
MesoscaleSounding
• 4 min meso • 1 hr CONUS• 4km GSD• 90% DOEE• 1.0 cm-1• 0.05K NEDT• 2km GSD possible
CoastalWaters
• 1 hr revisit• 75m GSD• 1000:1 SNR
Order of MagnitudeImprovement inCoastal Waters
Order of MagnitudeImprovement inMesoscale Sounding
Joe Criscione 301-286-00706
Serendipity
• CO2 spectral resolution is hard– Narrow absorption feature– Best measured in Longwave where detectors are high cost/risk
• H2O spectral resolution is easy (comparatively)– Detector technology is mature – Lots of redundancy in the spectrum
• The atmosphere is cooperating for once– H2O fluctuates rapidly, but it is easy to observe– Temperature is hard to observe, but it is relatively stable
• Finesse it– Accurately measure H2O often and everywhere– Accurately measure temperature only in the CONUS/mesoscale regions
Joe Criscione 301-286-00707
Feasibility
• Adding ~100 H2O channels to ABI+
– Data rate increase not overwhelming
• 100 at 10km = 1 at 1km
– Continuous variable filter on top of 2D array
• Same front end as current ABI concept
• Adds one filter and one detector array
• 6-8 micron region has mature detector technology
• Can tolerate noise and missing channels
Linear Variable FilterOptical Coating Laboratory
Inc.http://www.ocli.com/pdf_files/products/lvf_faqs.pdf
Joe Criscione 301-286-00708
Feasibility (cont’d)
• 60 cm aperture for HES+/-– SEVIRI has 50 cm aperture
• Spinning Enhanced Visible and Infrared Imager• Flying on MSG right now• Has a single axis scanner• Weighs 260 kg (HES mass budget is 280 kg)
• Spacecraft pointing– Civilian high resolution LEO satellites point at targets with a 16,000 mph
ground track• GEO has a ground track of 0 mph
– Can use same bus for both satellites• Solar array can tilt 15 degrees off-normal with little effect on power• GOES-N bus could slew from nadir to edge of earth in ~2 minutes• Could raster scan CONUS with very little time wasted in slews
– Need to examine method for downlinking science data
Joe Criscione 301-286-00709
Concept of Operations
• ABI+ – Uses Kalman filter to track atmospheric state
• Can use LEO observations to initialize Kalman filter• Tracking atmospheric state instead of retrieving state• Distribute atmospheric state hourly on 10km grid
– Potential for other products• Can observe winds at varying altitudes• Can distribute standard deviation of retrievals with hourly state
– Identifies targets for HES+/-
• HES+/-– Raster scans CONUS when there are no Regions-Of-Interest
• Can interleave Regions-Of-Interest with CONUS scans– Has high resolution land bands as well as fire channel– Can re-initialize parts of full disk that fall out of convergence for the ABI+
Kalman filter (no need to wait for LEO pass)
• ABI+, HES+/-, and NPOESS work as integrated system
Joe Criscione 301-286-007010
Conclusion
• Full-Disk/Region-Of-Interest Partitioning
– Sacrifices spectral resolution of full disk soundings
– No impact to full disk imaging products
– Order of magnitude improvement to severe weather/mesoscale soundings
– Order of magnitude improvement to coastal waters
• Same cost and risk– Achieves gains by
optimizing spacecraft/instrument system
– Balances full disk sounding needs and instrument complexity
250m GSD
75m GSD