The Imager/Sounder Paradigm Revisited Third GOES-R Users Conference

1. The Imager/Sounder Paradigm Revisited Third GOES-R Users Conference Broomfield, ColoradoMay 11th, 2004 Joe Criscione, Jim Bremer, and Donald Chu Swales Aerospace

2. 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 301-286-0070

3. 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 301-286-0070

4. 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+/- Flow Instrument Architecture To Spacecraft 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 Joe Criscione 301-286-0070

5. Flow Instrument Architecture to S/C Architecture Target Pointing Bus Eliminate Scanner & DoubleAperture 60 cm Aperture No Scanner Move Full-Disk Sounding to ABI Mesoscale Sounding Full-Disk Imaging Full-Disk Sounding Coastal Waters • 4 min meso • 1 hr CONUS • 4km GSD • 90% DOEE • 1.0 cm-1 • 0.05K NEDT • 2km GSD • possible • 1 hr revisit • 75m GSD • 1000:1 SNR • 5 min revisit • 0.5 km VIS • 2.0 km IR • 300:1 SNR • 0.1K NEDT • 16 channels • 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) Order of Magnitude Improvement in Coastal Waters Order of Magnitude Improvement in Mesoscale Sounding Trade Spectral Resolution and NEDT for Revisit Time in Full-Disk Sounding What’s Changed? Current Architecture Proposed Architecture Imager (ABI) Sounder (HES) Full-Disk (ABI+) Region-Of-Interest (HES+/-) Nadir Pointing Bus Nadir Pointing Bus Nadir Pointing Bus 30cm Aperture 2-axis Scanner 30cm Aperture 2-axis Scanner 30cm Aperture 2-axis Scanner • Full-Disk • Imaging • 5 min revisit • 0.5 km VIS • 2.0 km IR • 300:1 SNR • 0.1K NEDT • 16 channels • Full-Disk • Sounding • 1 hr revisit • 10km GSD • 90% DOEE • 1.0 cm-1 • 0.1K NEDT • Mesoscale • Sounding • 4 min meso • 1 hr CONUS • 4km GSD • 64% DOEE • 1.0 cm-1 • 0.1K NEDT • Coastal • Waters • 3 hr revisit • 250m GSD • 300:1 SNR NEDT: Noise Equivalent Delta Temperature GSD: Ground Sample Distance DOEE: Detector/Optics Ensquared Energy cm-1: Spectral Channel Width in wavenumber Joe Criscione 301-286-0070

6. 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 301-286-0070

7. 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 Filter Optical Coating Laboratory Inc.http://www.ocli.com/pdf_files/products/lvf_faqs.pdf Joe Criscione 301-286-0070

8. 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 301-286-0070

9. 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 301-286-0070

10. Conclusion 250m GSD • 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 75m GSD Joe Criscione 301-286-0070