/W) with f/2 Cold Shield 2-19
ACKNOWLEDGMENTS
This report and the project it documents represents the product of a group of researchers from around the MITRE Corporation:
* Dr. Bruce Metcalf of MITRE's Optical Communications and Photonic System Group in Bedford, MA, performed the analysis and design work for the proposed focal plane array imaging instrument and provided section 2 of this report.
* Mr. Arnold Cherdak of MITRE's Center for Advanced Aviation System Development, System Engineering Division in Washington, DC, performed the Image Navigation and Registration study and provided section 3. Mr. Cherdak was also the report editor.
* Mr. E. G. Livaditis of MITRE's Weather Sensors and Systems Department in Washington, DC, performed the study of ground processing and provided section 4.
* Mr. Marvin Rosenbluth of MITRE's Weather Sensors and Systems Department in Washington, DC, performed the Deployment and Cost studies and provided section 5. Mr. Rosenbluth was the Principle Investigator for the project.
* Mr. Indar Bhatia and Mr. Alan Goldberg of MITRE's Space Projects Department provided the imager effective resolution analysis presented in Appendix B.
In addition to these primary contributors, several other MITRE staff members made contributions that must be acknowledged, including Dr. Robert T. Carlson for his insights and technical suggestions on the imager optoelectronics; Dr. Marvin D. Drake for ray tracing support; Mr. Jonathan D. Fridman for technical support in the imager design; Mr. Charles Lapinski for support in cost analysis; and Mr. Arthur Schwalb for keen insights in support of most of the activities of this project.
At several points along the way, we were privileged to have the advice and critique of several people from the government agencies that have responsibility for our nation's civilian operational remote sensing programs. Mr. W. John Hussey, Acting Deputy Assistant Administrator of the National Oceanic and Atmospheric Administration (NOAA)/National Environmental Satellite, Data, and Information Service (NESDIS) provided invaluable insights for our deployment studies and regarding the government's technical requirements. Mr. Gary Davis of NOAA/NESDIS and Mr. Thomas McGunnigal of the NOAA System Program Office provided interim review and offered important insights and advice on technical and deployment issues. Finally, Mr. Faris Kahwajy and Mr. Richard Reynolds of the NOAA/NESDIS Office of System Development offered insights and directed us to important information sources.
During the course of the project, we visited several focal plane array and system developers. These included Loral Imaging Systems, Phillips Laboratory (PL/VTPT), Santa Barbara Research Center, Amber Engineering Inc., Rockwell Science Center, and Hughes Space and Communications Group. We were impressed with their knowledge and experience, and our work benefited greatly from their critiques and useful suggestions.
Finally, the authors wish to thank several MITRE Corporation executives for their support in establishing this project: Dr. Ronald D. Haggarty, Vice President for Research and Technology; Dr. John J. Fearnsides, Senior Vice President and General Manager, Director of the Center for Advanced Aviation System Development; and Dr. R. M. Harris, Vice President of the Center for Advanced Aviation System Development. We hope the results justify their support.
Arnold S. Cherdak
Editor
TABLE OF CONTENTS
SECTION PAGE
1 INTRODUCTION 1-1
1.1 Purpose 1-1
1.2 Background 1-1
1.2.1 Polar Orbiting Operational Environmental Satellite Program (POES) 1-1
1.2.2 Geostationary Operational Environmental Satellite (GOES) Program 1-2
1.2.3 GOES I-M Series 1-3
1.3 MITRE Sponsored Research (MSR) Initiative 1-4
2 IMAGER TECHNOLOGY AND DESIGN CONSIDERATIONS 2-1
2.1 Introduction 2-1
2.2 Imager Performance Goals 2-2
2.3 Focal Plane Array (FPA) Technology 2-6
2.4 Telescope and Array Sizes 2-9
2.5 Scanning 2-15
2.6 Radiometric Performance 2-17
2.7 Detector Cooling 2-25
2.8 Design Considerations 2-27
2.9 Instrument Weight and Power 2-37
2.10 Summary and Conclusions 2-37
3 IMAGE NAVIGATION AND REGISTRATION 3-1
3.1 Introduction 3-1
3.2 GOES I Instruments 3-2
3.3 Approaches to Image Navigation and Registration 3-3
3.3.1 Acquisition of Overlapping Image Frames 3-6
3.4 Image Spatial Relationships 3-11
3.4.1 GOES I Technology 3-12
3.4.2 Array Detector Instruments 3-12
3.4.3 Pixel Spread 3-14
3.4.4 Image Smear 3-15
3.4.5 Field Rotation 3-17
3.5 Error Budget 3-22
3.6 Summary and Conclusions 3-23
4 GROUND-BASED PROCESSING OF FPA INSTRUMENT OUTPUT DATA 4-1
4.1 Introduction 4-1
4.2 Reference Ground Processing System 4-1
4.2.1 GOES I-M Ground Processing System 4-2
4.2.2 Spacecraft Support Subsystems 4-2
4.2.3 PG&D Subsystems 4-4
4.3 Data Reception 4-5
4.4 Calibration and Normalization 4-6
4.5 Earth Location and Gridding 4-8
4.6 Preparation for Distribution and Sector Distribution 4-12
4.7 Operating Scenarios 4-13
4.8 Summary and Conclusions 4-14
5 DEPLOYMENT 5-1
5.1 Context 5-1
5.2 Program Plan 5-2
5.3 Launch Opportunities 5-4
5.3.1 Commercial Communications Satellite Systems 5-4
5.3.2 Government Geostationary Satellite Systems 5-14
5.4 Operational Considerations 5-15
5.5 Cost Considerations 5-16
5.5.1 Projected In-Orbit Costs 5-16
5.5.2 Operating Costs 5-20
5.6 Summary and Conclusions 5-21
6 Summary of Conclusions 6-1
Appendix A Blackbody Radiation A-1
Appendix B Step-Stare FPA Imager System Effective Resolution B-1
Appendix C Weighting Function For Drift and Jitter C-1
Glossary GL-1
FIGURE PAGE
2-1 Scanning the Field of Regard 2-1
2-2 Blackbody Spectra and IR Channels 2-4
2-3 Responsivity Nonuniformity of IR Sensor Arrays 2-9
2-4 System Considerations 2-10
2-5 Two-Telescope Imager 2-12
2-6 Field of View for 30 cm f/12 Ritchey-Chretien Telescope 2-13
2-7 Field of View and Array Size 2-14
2-8 Redundant Arrays in the Field of View 2-14
2-9 TDI Scanning 2-16
2-10 Temperature Resolution 2-22
2-11 Inverse Planck Function for Channel 5 2-24
2-12 Quantization Noise Resolution for Channel 5 2-24
2-13 Reverse Turbo-Brayton Refrigerator with Multiple Heat Loads 2-27
2-14 Spectral Separation with a Grating 2-28
2-15 Detectivity Tradeoff (300 degree K Scene, 2[[pi]] sr FOV) 2-29
2-16 Telescope Geometry 2-31
2-17 First Aft Optics Design 2-32
2-18 Second Aft Optics Design 2-33
2-19 Cold Shield 2-35
2-20 Flux Ratio and Optics Temperature 2-36
3-1 GOES: Spacecraft Dynamic Environment for INR 3-4
3-2 Spacecraft Motion Definitions 3-5
3-3 Composite of Image Frames 3-8
3-4 Effects of Spacecraft Motions on Frame Use 3-9
3-5 Spread Due to Mechanical Rates 3-16
3-6 Image Object Smear 3-18
3-7 Image Smear Due to Object Velocity 3-19
3-8 Scan Axis Directions 3-20
3-9 Frame Rotation Illustration 3-21
4-1 GOES I-M Satellite Support Subsystems 4-3
A-1 Solid Angle from Blackbody to Detector Aperture A-3
A-2 Blackbody Spectral Radiant Sterance A-4
B-1 A Typical Spacecraft Line-of-Sight Error PSF B-4
B-2 Typical Frequency Spectrum of LOS Point Spread Distribution B-5
B-3 Weighting Function for Jitter and Drift B-7
B-4 Normalized LOS PSD Curves B-9
B-5 Modified Drift Weighting Function G1(a,b) B-10
B-6 Modified Jitter Weighting Function [1-G1(a,b)] B-10
LIST OF TABLES
TABLE PAGE
2-1 Imager Resolution Goals 2-3
2-2 Desired (And GOES I-M) NEdT Performance Goals 2-3
2-3 Photon Sterance Levels (photons/sec*cm^(2)*sr) and Relative Temperature Derivatives (K-^(1)) for the IR Channels 2-5
2-4 Radiant and Photon Sterance Levels for Channel 1 2-6
2-5 IR Detector Cutoff Wavelengths (um) 2-7
2-6 Diffraction Limited Telescope Apertures 2-11
2-7 Integration Times, TDI Dwells, and Attenuation 2-19
2-8 Background-Limited Detectivities (cm /W) with f/2 Cold Shield 2-19
2-9 NEDT WITH STEP-STARE SCAN (50% BLIP FOR CHANNELS 2 AND 3, 10% FOR 4 AND 5) 2-20
2-10 NEDT WITH TDI SCAN (50% BLIP FOR CHANNELS 2 AND 3, 10% FOR 4 AND 5) 2-21
2-11 Maximum Array Variations (percent) 2-22
2-12 System Focal Lengths 2-30
3-1 Frame Edge Overlap 3-10
3-2 GOES I Imager Predicted INR Performance 3-13
5-1 ITU Region 2 1992 In-Orbit Communications Satellites 5-5
5-2 Projected Replacement Satellites 5-11
5-3 ROM Cost Summary for Commercial Host Satellite 5-17