Small Satellites and RPAs in Global-Change Research P. Banks ]. Cornwall F. Dyson N. Fortson R.Garwin S. Koonin C.Max G. MacDonald S. Ride M. Ruderman S. Treiman J. Vesecky R. Westervelt F. Zachariasen ~.'~e ..:":lo. -'01"----/+-'- December 1992 ~~~ t~" g I .. ... _, I '--' • ..-..;.; "',' -~,..... r.J ' . .. •. ". .' I . I ]SR-91-330 I J . .L",., ... -.e& .. ~ ___~ :.-~-.---- ------------1 Approved (or public release; clstdbullon unimIIed. ; )::'." - : ~-i ~ • a:. :;------ --] 1 __ .- ~ .~L .... ___ ~ __ _ :__ A\''': ltlt 1 ~ n ... COdE'~l --J '("."J~ ~.-~·'io;" ~ JASON ,D.5t.- • ; ~;~~.gl I' The MITRE Corporation 7525 Coishire Drive McLean. VIrginia 22102-3481 I~-\I I (703) 883-6997 -----------------------------------_.... _-_.-...... Fonrt Approwd REPORT DOCUMENTATION PAGE OM. No. 07(u·<HBI """'tc,...".u"'9 bUnMft fOf' n'" (O".au," of ,"forma'IOti t1 ""'''Ited to ...,.,. I "'<Mar ~ '1'IDOftW. ,1\(1 ..... t.-..; tPl. ~.~ for r..-,.... ,~ I"'~OI'\. WW<ftt"'9 .'I'Il'''9 deu tOUt'tft. 91u..rt", ..... I'ftIltlUfl't"9 trw data ,.....,.• ftiIf (0",,",,''''9 .ftC! '., •...,1"9 tfte call«tIOf'\ of ''''OI''''.ttOft \end cOfI'II"...,a ':lltcJ'rtq U't" bu,"" fttJ"'l1. Of I,.. 0",-", tJOIIt't at tMl colle<t_ "'1fI1OnN_. 1M....... ~t_ for ''''''''''9 t~" __. '0 w ..... nqton ......." ... _0(". Olrfttor.t. or Inlor"'."011 0..._ end --.. 111\ j~ ___ 0_"'9"'''' __ I~ .•'''""Oft. v 22201"J02 .•nd to , ... OffICI 01 ~.noq .... ~t • ..., lU099t. P_or. A... ..moto "'ot«t(07(I&.G1"1. W_lnqtOft. OC 20\0) 1. AGENCY USE ONLY (L ••.,. bI."k) Il. REPORT DATE IJ. REPORT TYPE AND OATES COVERED December 1. 1992 ... TITLE AND SUBTITU 5. FUNDING NUMBERS Small Satellites and RPAs in Global-Change Research 6. AUTHOR(S) PR - 8503A P. Banks. J. Cornwall. F. Dyson. N. Fortson. P. Garwin. S. Koonin. C. Max. G. MacDonald. S. Ride. M. Rudennan. S. Treiman. J. Vesecky, R. Westervelt, F. Zachariasen 7. PERFORMING ORGANllA TlON NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZA TION REPORT NUMBER The MITRE Corporation JASON Program Office AlO 7525 Colshire Drive JSR-91-330 ,/ McLean. V A 22102 9. SPONSORINGiMONITORING AGENCY NAME(S) AND ADDRUS(ES) 10. SPONSORING I MONITORING AGENCY REPOAT NUMBER Department of Defense JSR-91-330 Washington. DC 20301-7100 11. SUPPUMENTARY NOTES 121. DISTRIBUTION I AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Approved for public release; distribution unlimited. 1). ABSTRACT (M•• ,mum 100 words) This report contains an investigation of those global change science problems that can be addressed by remotely piloted aircraft or by small satellites. including the relationship to the NASA EOS program. New types of measurements that could be made possible by such satellite or aircraft platforms are pointed out. Issues of technical feasibility and cost are examined. as well as the role of new technology developed through DOD and other programs. Possible joint DOD/Global Science satellite missions are also discussed. , ... SUBJECT TlRMS 1S. NUMIlR OF PAGES remotely piloted aircraft. cloud albedo. oxidants. imaging IR 16. PRICE CODE detectors. LIDARS 17. SECURITY aASSIFICA TlON II. SECURITY CLASSIFICATION 19. SECURITY aASSIFICA TlON 20. LIMITATION OF ABSTRACT OF RfPORT OF THIS PAGE Of ABSTRACT UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED SAR NSN 7540~1·280·5500 St.nd.,d ~o,'" 298 (R.v 1 89) P"..w:"'" bt .l'1li'" \ta 11'·'1 Jq" IQl Abstract This report contains an investigation of those global change sci­ ence problems that can be addressed by remotely piloted aircraft or by small satellites, including relationship to the NASA EOS program. New types of measurements that could be made possible by such satel­ lite or aircraft platforms are pointed out. Issues of technical feasibility and cost are examined, as well as the role of new technology devel­ oped through DOD and other programs. Possible joint DOD/Global Science satellite missions are also discussed. 111 Contents 1 SMALL SATELLITES AND RPAs: SUMMARY AND CONCLUSIONS 1 1.1 Scientific Scope of the Study . 2 1.2 Remotely Piloted Aircraft ... 3 1.2.1 Potential Advantages of RPAs . 4 1.2.2 Issues to be Resolved. 6 1.2.3 Instrumentation and Measurement Requirements 7 1.3 Small Satellites . 9 1.3.1 Potential Advantages and Disadvantages . 9 1.3.2 Lightweight Support Hardware and Instrumentation. 10 1.3.3 Specific Small-Satellite Missions and Instruments .. 12 1.4 A DARPA Joint Global Change/Surveillance Satellite 14 1.4.1 Visible/IR Cloud, Radiation, and Surveillance 14 1.4.2 Dual-Purpose Lidar . 15 1.5 Role of DOD Science and Technology . 16 1.6 Recommendations.................... 1 7 2 SCIENTIFIC OBJECTIVES OF GLOBAL CHANGE RESEARCH 21 2.1 General Types of Observational Missions . 21 2.2 Major Scientific Issues in Global Change Research . 23 3 CLOUDS AND RADIATION 29 3.1 Introduction................. 29 3.2 Simple Model of Cloud Optical Properties 35 3.3 Cloud Forcing . 39 3.4 Factors Affecting the Radiation Balance of Clouds . 43 3.5 Global Warming. 46 4 THE USE OF RPAS IN SUPPORT OF THE ATMOSPHERIC RADIATION MEASUREMENT PROGRAM 51 4.1 Small RPA Instrument Packages for ARM Measurements 52 4.2 RPA Platform Requirements. 56 4.3 Manned Aircraft vs. Existing and Proposed RPAs 62 4.4 FAA Requirements . 67 v 4.5 Conclusions Regarding RPAs in ARM ............. , 68 4.6 Data Management ........................ 70 4.7 A Role for Balloon Flights: Instrument Testing and Development 72 5 INFLUENCING CLOUD ALBEDO FOR PROCESS DIAGNOSTICS 77 5.1 Introduction . 77 5.2 Cloud Albedo . 78 5.3 Seeding Droplet Growth 79 5.4 Observed Cloud Condensation Nuclei 87 5.5 Sea Surface Sulfur Emission and Oxidants 90 5.6 Cloud Process Experiments .. 91 6 OZONE DEPLETION 97 6.1 Present Situation in the Arctic. 97 6.2 Obtaining better information 99 7 IR DETECTORS FOR RPAs AND SMALL SATELLITES 105 7.1 Classes Of Imaging IR Detectors. 105 7.2 A pplications Of Imaging IR Detectors For Radiation Measurements . 109 8 POTENTIAL USES FOR SMALL SATELLITES IN THE STUDY OF GLOBAL CLIMATE 115 8.1 Process studies .... 115 8.2 Long-term Monitoring .. 118 8.2.1 Precursors to EOS .... 118 8.2.2 Adjuncts to EOS (satellites which could fly simultaneously with EOS) . 119 9 CANDIDATE SCIENCE MISSIONS FOR SMALL SATELLITES 121 9.1 Introduction........ 121 9.2 Specific Proposed Missions . 122 10 ISSUES IN THE CHOICE OF ORBITAL COVERAGE FOR SMALL SATELLITES 129 10.1 Flexible Space-Time Coverage .................. 129 VI 10.2 Implications of Diurnal Variability. 134 10.2.1 The Context of Diurnal Variability . 134 10.2.2 An Important Role For Small Satellites . 136 11 SMALL SATELLITE INSTRUMENTS TO ADDRESS PROBLEMS FACING PRESENT EOS-CLASS EXPERIMENTS 147 11.1 Solid-state Lasers for LIDARS and Laser Rangers . 147 11.2 Synthetic Aperture Radars (SARs) .. 148 11.3 A High Resolution Imaging Spectrometer (HIRIS) . 152 12 SOME POSSIBILITIES FOR JOINT SURVEILLANCE /GLOBAL CHANGE SMALL SATELLITES 157 12.1 Surveillance vs Global Change. 158 12.:2 Visible/IR Satellite . 161 12.3 Dual-Mode Lidar Satellite . 164 12.4 The DARPA Proposal . 167 A PRE-1998 EARTH SYSTEM SCIENCE EXPERIMENTS CURRENTLY PLANNED FOR SATELLITES 171 B MULTIPLE SATELLITE PERFORMANCE FOR EOS MISSION: (Presentation Made by R.L. Garwin to the EOS Engineering Review Advisory Committee, La Jolla, CA, July 1991) 185 B.l Coincidence in Space and Time . 185 B.2 Pointing . 189 B.3 Pointing Accuracy and Stability. 190 VII 1 SMALL SATELLITES AND RPAs: SUMMARY AND CONCLUSIONS JASON has now conducted two studies on the use of small satellites and remotely-piloted aircraft (RPAs) in global change research, with special reference to the DOE Atmospheric Radiation Measurement (ARM) program and to DARPA's Small Satellite program. The studies centered around two meetings, one in January and the other in June, 1991, to which we invited representatives of most areas of the global change program and of the DOD satellite science and technology community. We have already issued a re­ port on the Winter Study. Here we present a more comprehensive report based mainly on our Summer Study. In this first section, we summarize the main themes and results, leaving a more complete discussion to later sections devoted to each major topic. The charge from DOE and DARPA to JASON was to elucidate global change science problems that can be answered by small satellites and RPAs; investigate the role of DOD technology in global change research; and (for DARPA) propose small satellite sensor packages which simultaneously ad­ dress a remote-sensing mission of interest to DOD and a related one of in­ terest in global change science. In addition, we were asked to brief the EOS Engineering Review on our findings. The Winter Study served to introduce people from a variety of techno­ logical communities to one another's problems and possible mutual interests. Our report on this study was itself introductory, dealing in broad terms with the technology of RPAs, small satellites, their instrumentation and support 1 hardware, and the scientific issues they could address. It was clear during the Winter Study that the involved communities' knowledge of each other's needs was not necessarily as great as their interest in each other. At the Summer Study we found that many of the participants had made progress since the Winter Study and could, for example, make definite and quantitative proposals for small lightweight instruments for RPAs and small satellites. Our Summer Study report in turn deals as quantitatively as we now can with the issues first raised in the Winter Study and their further evolution as of the summer of 1991. 1.1 Scientific Scope of the Study We investigated those parts of global change research which are rea­ sonably closely connected with the ARM program.