Search Strategies for a Wide-Field Electro-Optic Sensor

Search Strategies for a Wide-Field Electro-Optic Sensor R. Lambour, E. Pearce, R. Sayer 21 Space Control Conference 4 April 21 This work sponsored by the Air Force under Air Force Contract F19628--C-2. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the United States Air Force. 21 Space Control Conf.-1

REPORT DOCUMENTATION PAGE Form Approved OMB No. 74-188 Public reporting burder for this collection of information is estibated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burder to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (74-188), 1215 Jefferson Davis Highway, Suite 124, Arlington, VA 2222-432. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 4-4-21 Conference Proceedings (Briefing) 4. TITLE AND SUBTITLE Search Strategies for a Wide-Field Electro-Optic Sensor Unclassified 6. AUTHOR(S) Lambour, R. ; Pearce, E. ; Saver, R. ; 7. PERFORMING ORGANIZATION NAME AND ADDRESS 244 Wood Street Lexington, MA242-918 9. SPONSORING/MONITORING AGENCY NAME AND ADDRESS Lincoln Laboratory Massachusetts Institute of Technology 244 Wood Street Lexington, MA242-918 3. DATES COVERED (FROM - TO) 3-4-21 to 5-4-21 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 8. PERFORMING ORGANIZATION REPORT NUMBER 1. SPONSOR/MONITOR'S ACRONYM(S) 11. SPONSOR/MONITOR'S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT APUBLIC RELEASE, 13. SUPPLEMENTARY NOTES See Also ADM1334, Proceedings of the 21 Space Control Conference (19th Annual) held in Lincoln Laboratory, Hanscom AFB, MA on 3-5 April 21. 14. ABSTRACT? Search simulations designed to demonstrate capability of 4-cm Schmidt class telescope with MIT/LL CCID-16 camera? Results suggest that most of the visible deep space objects can be detected multiple times in a single night of search operations? Results suggest significant search capability to augment current GEODSS tasking? Low-risk? Search rates almost 1 times GEODSS? Testing of these search strategies planned for April-May 21 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Public Release a. REPORT Unclassified b. ABSTRACT Unclassified c. THIS PAGE Unclassified 18. NUMBER OF PAGES 34 19. NAME OF RESPONSIBLE PERSON Fenster, Lynn lfenster@dtic.mil 19b. TELEPHONE NUMBER International Area Code Area Code Telephone Number 73767-97 DSN 427-97 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39.18

Outline Introduction and Goals Simulation Design Simulation Results Summary and Recommendations 21 Space Control Conf.-2

Introduction GEODSS augmentation concepts under study Inexpensive low-risk augmentation to deep space capacity Many small tracking systems proposed and demonstrated: MOSS, PIMS, Raven (SATA, SOA), ASTA Small search systems Goal Support transition of CONOPS from tracking to search MIT/LL CCID-16 imagers enabling technology for use of 4 cm class Schmidt telescopes for deep space search Adequate sensitivity for >9% of current deep space catalog Develop strategies for use of 4-cm class Schmidt telescopes for deep space search and GEODSS augmentation 21 Space Control Conf.-3

GEODSS Auxiliary Prototype Telescope 4 cm f/1.7 folded Schmidt Original GEODSS Aux prototype telescope Performance with CCID-16 Sensitivity 16.2 m v 5.92 X 4.54 FOV Projected Search Rate >65 deg 2 /hr Small Search Telescope Demo ETS 4 cm f/1.7 Telescope with CCID-16 Camera. 21 Space Control Conf.-4

GEODSS Auxiliary Prototype Telescope 4 cm f/1.7 folded Schmidt Original GEODSS Aux prototype telescope Performance with CCID-16 Sensitivity 16.2 m v 5.92 X 4.54 FOV Projected Search Rate >65 deg 2 /hr Small Search Telescope Demo GEO2 GEO1 Moly GEO GEODSS 21 Space Control Conf.-4 1 2 3 4 5 Effective Search Rate Comparison (deg 2 /hr) ETS 4 cm f/1.7 Telescope with CCID-16 Camera.

ETS 4 cm F/1.7 Search Simulation Development Goal: Develop search strategies to support space situational awareness using data collected during wide-field search operations Cover wide range of orbit classes: Approach: Geosynchronous Molniya (near apogee) Semi-synchronous orbits Develop search strategies to maximize leakproofness Simulate search strategies and evaluate effectiveness Test useful strategies at ETS 21 Space Control Conf.-5

Outline Introduction and Goals Simulation Design Simulation Results Summary and Recommendations 21 Space Control Conf.-6

Deep Space Population Snapshot Geosynchronous Belt 18-33 E coverage E 9 Visible Sky at ETS 12 18 33 8 19 6 15 2 21 22 6 4 3 23 24 2 S 18 8 6 25 26 4 2 2 4 6 8 N 27 2 21 28 29 3 31 4 6 33 24 32 8 33 27 W 3 Molniya Apogee Ring ~6 declination 21 Space Control Conf.-7

Simulation Design: General Properties Field of View 5.92 x 4.54 Data Collection Five.4-sec frames/field Collection, step and settle time 1. sec/field Sensitivity 15.6 V m @.4 sec integration GEO Belt search: Align long axis of FOV (5.9 ) along GEO belt, center short axis (4.5 ) on GEO belt Single search stack complete in ~4 minutes Molniya Ring search: Cover 6 declination ring below Molniya apogee (~63 ) Align long axis of FOV along 6 declination line Single search stack complete in ~4 minutes 21 Space Control Conf.-8

Simulation Design: Revisit Intervals Frequent revisit of fields improves leak-proofness of fence Revisit interval determined by object rates and sensor FOV Goal: Revisit field before object has time to cross FOV Minimum revisit time determined by short axis of FOV 4.54 vsin i v vcos i 5.92 Object Rate (arcsec/sec) Revisit Time (min) GEO ~15 18 Semi-Synch ~3 9 Molniya ~1 27 21 Space Control Conf.-9

Simulation Design: Other Concerns Elevation limit set at 16 no data collection below horizon Simulation run from nautical twilight to nautical twilight Simulation run for a summer night (Day 15 of 2) Weather assumed green for entire night Lunar keep-out zone in place 5 + (3 * fraction illuminated): 5 at new moon, 35 at full moon Simulation makes use of the entire RSO catalog (~9 objects) Simple analytic model used to check for objects in Earth shadow Unilluminated objects considered undetectable Object brightness determined from SBV photometric database SBV photometric observations fit to diffuse sphere model to obtain phase angle dependence 21 Space Control Conf.-1

Simulation Design: Search Patterns Multiple search patterns devised GEO belt: 7 GEO 1-stack, 4-stack One stack, Three stack, Four stack Center all searches on GEO belt Covers 4.54, 13.1, 17.2 latitude Covers 645, 1933, 2575 deg 2 Complete in 4, 12, and 16 minutes Molniya Ring One stack centered on 6 declination Complete in 4 minutes Elevation 6 5 4 3 2 1 19 18 2 21 24 23 22 25 8 1 12 14 16 18 2 22 24 26 28 Azimuth 26 27 28 29 3 31 32 33 Two stack centered at 6 and 55.7 declination Complete in ~9 minutes 21 Space Control Conf.-11

Outline Introduction and Goals Simulation Design Simulation Results Summary and Recommendations 21 Space Control Conf.-12

Simulation Results: GEO One-stack + Molniya Ring One-stack GEO belt plus one-stack Molniya ring Search GEO belt 3 times (~12 minutes) then divert to Molniya Ring (~4 minutes) Compare GEODSS search times of ~3 min for GEO belt and ~3 min for Moly ring 21 Space Control Conf.-13

Simulation Results: GEO One-stack + Molniya Ring 875 individual objects detected GEO search leak proof for GEO objects with inclination < 6 21 Space Control Conf.-14

Simulation Results: GEO One-stack + Molniya Ring 875 individual objects detected GEO search leak proof for GEO objects with inclination < 6 Class # Detected # Visible % GEO 183 219 83.6 SEMI 57 91 62.6 MOLY 18 243 74.1 3 25 Number of Objects 2 15 1 5 GEO SEMI MOLY 21 Space Control Conf.-14

Simulation Results: GEO One-stack + Molniya Ring 875 individual objects detected GEO search leak proof for GEO objects with inclination < 6 Class # Detected # Visible % GEO 183 219 83.6 SEMI 57 91 62.6 MOLY 18 243 74.1 3 16 Number of Objects 25 2 15 1 Number of Objects 14 12 1 8 6 4 GEO SEMI MOLY 5 2 21 Space Control Conf.-14 GEO SEMI MOLY 2 4 6 8 Number of Detections

Simulation Results: GEO One-stack + Molniya Ring 875 individual objects detected GEO search leak proof for GEO objects with inclination < 6 Most visible objects detected in single night s search Class # Detected # Visible % GEO 183 219 83.6 SEMI 57 91 62.6 MOLY 18 243 74.1 3 16 Number of Objects 25 2 15 1 Number of Objects 14 12 1 8 6 4 GEO SEMI MOLY 5 2 21 Space Control Conf.-14 GEO SEMI MOLY 2 4 6 8 Number of Detections

Search Strategies: GEO Three-stack + Molniya Ring Search GEO belt 1 time (~12 minutes) then divert to Molniya Ring (~9 minutes) Compare GEODSS search time of ~1.5 hours for GEO and ~1.1 hours for Moly ring 21 Space Control Conf.-15

Search Strategies: GEO Three-stack + Molniya Ring 19 individual objects detected GEO search leak-proof for GEO objects with i < ~12 21 Space Control Conf.-16

Search Strategies: GEO Three-stack + Molniya Ring 19 individual objects detected GEO search leak-proof for GEO objects with i < ~12 Class # Detected # Visible % GEO 29 219 95.4 SEMI 65 9 72.2 MOLY 19 242 78.5 3 25 Number of Objects 2 15 1 5 GEO SEMI MOLY 21 Space Control Conf.-16

Search Strategies: GEO Three-stack + Molniya Ring 19 individual objects detected GEO search leak-proof for GEO objects with i < ~12 Class # Detected # Visible % GEO 29 219 95.4 SEMI 65 9 72.2 MOLY 19 242 78.5 3 16 25 14 GEO SEMI MOLY Number of Objects 2 15 1 Number of Objects 12 1 8 6 4 5 2 GEO SEMI MOLY 1 2 3 4 21 Space Control Conf.-16 Number of Detections

Search Strategies: GEO Three-stack + Molniya Ring 19 individual objects detected GEO search leak-proof for GEO objects with i < ~12 More visible objects detected in single night s search Class # Detected # Visible % GEO 29 219 95.4 SEMI 65 9 72.2 MOLY 19 242 78.5 3 16 25 14 GEO SEMI MOLY Number of Objects 2 15 1 Number of Objects 12 1 8 6 4 5 2 GEO SEMI MOLY 1 2 3 4 21 Space Control Conf.-16 Number of Detections

Search Strategies: GEO Four-stack + Molniya Ring Search GEO belt 1 time (~16 minutes) then divert to Molniya Ring (~9 minutes) Compare GEODSS search time of ~2 hours for GEO and ~1.1 hours for Moly ring 21 Space Control Conf.-17

Search Strategies: GEO Four-stack + Molniya Ring 114 individual objects detected GEO search leak-proof for GEO objects with i < ~14 21 Space Control Conf.-18

Search Strategies: GEO Four-stack + Molniya Ring 114 individual objects detected GEO search leak-proof for GEO objects with i < ~14 Class # Detected # Visible % GEO 212 219 96.8 SEMI 64 92 69.6 MOLY 188 246 76.4 3 25 Number of Objects 2 15 1 5 GEO SEMI MOLY 21 Space Control Conf.-18

Search Strategies: GEO Four-stack + Molniya Ring 114 individual objects detected GEO search leak-proof for GEO objects with i < ~14 Class # Detected # Visible % GEO 212 219 96.8 SEMI 64 92 69.6 MOLY 188 246 76.4 3 16 25 14 GEO SEMI MOLY Number of Objects 2 15 1 Number of Objects 12 1 8 6 4 5 2 21 Space Control Conf.-18 GEO SEMI MOLY 1 2 3 4 5 6 Number of Detections

Search Strategies: GEO Four-stack + Molniya Ring 114 individual objects detected GEO search leak-proof for GEO objects with i < ~14 More visible objects detected in single night s search Class # Detected # Visible % GEO 212 219 96.8 SEMI 64 92 69.6 MOLY 188 246 76.4 3 16 25 14 GEO SEMI MOLY Number of Objects 2 15 1 Number of Objects 12 1 8 6 4 5 2 21 Space Control Conf.-18 GEO SEMI MOLY 1 2 3 4 5 6 Number of Detections

Summary Search simulations designed to demonstrate capability of 4-cm Schmidt class telescope with MIT/LL CCID-16 camera Results suggest that most of the visible deep space objects can be detected multiple times in a single night of search operations Results suggest significant search capability to augment current GEODSS tasking Low-risk Search rates almost 1 times GEODSS Testing of these search strategies planned for April-May 21 21 Space Control Conf.-19