Changing the economics of space. Redefining the word Responsive in Operationally Responsive Space

Transcription

1 Changing the economics of space Redefining the word Responsive in Operationally Responsive Space Dr. Stuart Eves SSTL February 2009 Defining Responsive Responsive means flexible and agile, as well as quick Webster s Dictionary Readily reacting to suggestions and influences Oxford English Dictionary 1. responding readily and positively. 2 in response; answering This presentation addresses the multiple operational modes available from small satellites and constellations of small satellites...and hence their potential to flexibly answer a range of information requirements

2 User Communities for Responsive Space Operational and Tactical Intelligence Strategic Intelligence Homeland Security Training These user communities have differing requirements for parameters such as:- Resolution Timeliness Area coverage Geolocation accuracy Etc. EO surveillance missions Very timely, wide-area surveillance from lower resolution imagers, cueing close-up look from hi-resolution satellites TEHRAN AIRPORT

3 TopSat (Tactical Optical Satellite) 2.8 m resolution panchromatic imaging 5.6 m resolution, 3-band (R,G,B) multi-spectral imaging Enhanced microsatellite: 120 kg High performance ADCS Ground motion compensation Rapid slewing 5 images per day Nominal 1 year lifetime Orbit: 700km, sun-synchronous Direct data delivery to mobile ground terminal Final cost ~ 13.5M TopSat sets a new world record for resolution per mass of satellite Rutherford Appleton Laboratory TOPSAT S AGILITY Standard image acquisition typically 2 seconds Pitching image acquisition typically 8 seconds 15km 15km TopSat s agility allows it to collect more light from the scene and hence produce a higher quality image

4 Low-light Imaging The agility of small satellites allows them to collect more light from a scene and hence produce a higher quality image 15km Images can be collected at different local times of day Ability to image can be maintained if sun-synchronous condition degrades Crucially, the ability to launch into lower inclination orbits and cope with variable lighting conditions Standard access times Local Noon Enhanced access times Lower Inclination Orbits Orbit inclination Most imaging systems operate from polar orbits due to lighting constraints Polar 65º 40º 28º 16º 9º 7º Number of visits to location in 3 days TopSat could operate from any orbit and hence provide greatly enhanced revisits to regional users

5 Coverage Performance A near-polar sun-synchronous orbit would provide about 250 imaging opportunities of Tehran in one year A 35 or 45 inclination would more than double this to over 500 accesses per year However, the daytime passes are more asymmetrically distributed Two solutions:- Use a second satellite phased to ensure that there are no long gaps in coverage Use an IR imager or a SAR that can exploit the night-time imaging opportunities ONE YEAR COVERAGE MAP FOR 700 KM ALTITUDE SUN-SYNCHRONOUS ORBIT DAY-TIME COVERAGE PATTERN FOR 700 KM ALTITUDE SUN-SYNCHRONOUS ORBIT DAY-TIME COVERAGE PATTERN FOR 45 INCLINATION, 700 KM ALTITUDE ORBIT SSTL 300 Optical Imager 3 Imagers Panchromatic 1.2 m resolution; 15 km swath 4 Band Multi-Spectral 2.4 m resolution; 20 km swath 4 Band Multi-Spectral 22 m resolution; 300 km swath Multiple Operational Modes Spot, Strip, Fast-response, Area, Stereo Possible additional modes include Low-elevation, Line of communication, Super-resolution, Change Detection, Joystick Control High accuracy pointing (better than 15 m geolocation) 2 Day Revisit to Anywhere on Earth Fast slewing in roll and pitch 7 Year Life images per day Mass kg

6 Next Generation Optical System Live Webcam Link

7 Very High Agility Small satellites can achieve much faster attitude-change manoeuvres than larger platforms SSTL 300 can achieve Roll manoeuvre of 35 degrees in 20 seconds Ability to slew to any attitude within a 45 degree cone from nadir Accurate pointing maintained during slew through precisely calibrated inertia tensor Opportunities for data downlink between imaging activities Multiple Operational Modes High small satellite agility allows a range of responsive modes of operation Strip 4 Manoeuvre time Strip 3 Manoeuvre time 2 Fast-Response Single Scene Imaging 1 Extended Strip Imaging Strip 2 Manoeuvre time Strip 1 In-pass Stereo Mode Imaging Line of Communication Mode Imaging Area Mode Imaging Super-Resolution Mode Imaging Low-Elevation Mode Imaging

8 Potential to compile image strips of up to 1200 km in length Swath Width 12 km Resolution 1.2 m Off-nadir capability up to 45 degrees Near-real time data downlink Extended Strip Imaging Image footprint 12 x 12 km Resolution 1.2 m Spot Imaging Roll manoeuvre of 45 degrees in about 25 seconds Ability to image at any attitude within a 45 degree cone from nadir Gyros used to supplement star trackers during a slew Continuity of measurement such that post-slew settling can be achieved quickly

9 Stereo Mode Imaging Combination of two images Footprint 12 km x 12km 2 1 Resolution 1.2 m Pitch angles of possible Area Mode Imaging Used to provide wide-swath high-resolution imagery Can cover an area up to 4 x 4 scenes in a single pass Area coverage 48 km x 48 km Resolution 1.2 m

10 Super Resolution Mode (SRM) Standard mode Satellite sensor operates in push-broom mode Baseline resolution m Typical swath 12 km Super Resolution Mode Satellite yaws 45 degrees and pitches backwards rapidly to allow smaller GSD both across and along track Expected resolution ~ 0.7 m Typical swath ~ 8.5 km SRM has the potential to deliver 40% improvement in baseline resolution Degree of yaw and pitch can be varied Line of Communication Mode Track-following Multiple scenes and strips with high-resolution imager Strip 4 Manoeuvre time Strip 3 Used to follow a meandering target on a single satellite pass Manoeuvre time Applications include the monitoring of :- Roads Waterways Railroads Borders Coasts Pipelines Powerlines Strip 2 Manoeuvre time Strip 1

11 Low Incidence Imaging Mode Principally for use over maritime areas Artificially large footprint on surface of the ocean (e.g. ~135 km at a satellite elevation angle of 10 degrees) Lower resolution (e.g. ~4.4 m, at a slant range of about 1830 km) Change Detection Mode The 5-detector array comprises infra-red, red, panchromatic, green and blue detectors Each detector is swept across the ground at a slightly different time Appropriate processing reveals the presence of moving targets in the scene

12 Aircraft Detection - Results NATS Track Detection of Boeing 747 Dipole in Frame Differenced Image Intensity Profile through the Dipole Contrail First Image Clouds Second Image Margate Dipole Difference Image Differenced Image (after processing) Copyright QinetiQ 2003 In-theatre Operations 8-10 MINUTES ~4 MINUTES ~ 2 MINUTES ~1 MINUTE ~2 MINUTES IMAGING ACTIVITY SATELLITE RISES IMAGE CO-ORDINATES COMMAND UPLINK FROM THEATRE IMAGE DATA DOWNLINK DIRECT TO THEATRE SATELLITE SETS THEATRE OF OPERATIONS Theatre operations concept for MicroSAR

13 Communications Downlink data rates of up to 300 Mbps feasible from steerable X-band satellite antenna Use of two antennas operating at different polarisations gives a total rate of 600 Mbps 400 images per day can be down-linked to a network of ground sites Responsive Communications Inter-satellite links for commandfile transfer via GEO would allow satellites to be pre-configured for all relevant imaging passes In-theatre downlink to deliver data immediately to users Possibility of joystick control mode from theatre

14 Ground Stations Ground Stations Number and distribution of ground stations will determine- Overall end-to-end speed of response Capacity of system number of images per day Communications between ground station facilities assumed Allows allocation of command authority over specific time periods or geographic locations Allows coordination of system resources, (memory/power) Variation of the in-plane separation between satellites during the mission can provide:- Different area coverage rates Different access statistics Small separations (a few degrees) allow:- Contemporaneous access by different sensors at similar geometries Very timely change detection Wider separations (up to 40 ) allow:- Contemporaneous Stereo Contemporaneous BRDF measurements Near-real-time cueing from one satellite to the other concerning cloud conditions, possible target locations, etc. Very wide separations (> 40 ) allow:- Shorter access times Higher area coverage rates Responsive CONOPS

15 Conclusions Responsive space is about more than the time domain It involves agility and flexibility Individual satellites can have different modes of operation The constellation configuration and CONOPS can also be varied CAIRO AIRPORT Changing the economics of space Thank you Surrey Satellite Technology Ltd. Tycho House, 20 Stephenson Road, Surrey Research Park, Guildford, Surrey, GU27YE, United Kingdom Tel: +44(0) Fax:+44(0) Web:

16 Changing the economics of space Back-up slides Surrey Satellite Technology Ltd. Tycho House, 20 Stephenson Road, Surrey Research Park, Guildford, Surrey, GU27YE, United Kingdom Tel: +44(0) Fax:+44(0) Web: Skysight Context Persistence Spatial resolution Vulnerability Hours Air Platforms allow close-look look Decimeters Low Minutes Metres High Reach Global AOR Days Hours Timeliness 100 s of m High 10 s of km 2 Satellites provide situational awareness 10 s of m Geolocation Accuracy Low Intrusiveness 100 s of km 2 Space + Air = comprehensive capability Area Coverage Rate

17 By Analogy The human sensing system has two long-range sensors, eyes and ears Ears are onmi-directional, and can cue the high-acuity field of the eye to an accuracy of about 5 degrees Eyes operate in two modes:- A five degree high acuity mode A sixty degree peripheral vision mode that uses change detection for cueing The high acuity field can be steered within the peripheral field of view by eye motion The peripheral field can be steered omni-directionally by head and body motion Variations in focus, (or area coverage), are possible Communication of commands and data are instantaneous The space sensing system has two long-range sensors, IMINT and SIGINT SIGINT is onmi-directional, and can cue the high-acuity field of the IMINT sensors to an accuracy of about 5 km IMINT operates in two modes:- Small footprint high acuity modes from high-res EO and SAR Peripheral vision modes from wide-area EO or SAR The high acuity fields can be steered within the peripheral field of view by electronic steering The peripheral field can be steered omnidirectionally by satellite motion Variations in focus, (or area coverage), are possible Communication of commands and data are instantaneous The Eyes and Ears of ORS A constellation of low-cost small satellites with complementary sensors: Electro-Optical, SAR, SIGINT Orbits would be selected to provide the capability for collocated, contemporaneous, comparable collection of data when required Performance parameters specified with complementary fields of regard to facilitate cueing and fusion of data

18 Military and Security Surveillance Needs Timely Wide-Area Capability For cueing other highresolution satellite sensors For cueing airborne sensors For data fusion Multiple Platform Types Manned and Unmanned Air Space Multiple Sensor Types Optical Infra-Red SAR SIGINT Effective Communications Situating the Appreciation Our starting point was to evaluate which group of users ORS should principally be designed to support We have assumed brigade level here A brigade has surveillance requirements in terms of:- Area of intelligence interest Currently between 1,000 and 2,000 km, and increasing with weapon system range Timeliness of decision making Currently between 4 and 6 hours, and shortening with demands for increased tempo Resolution Targets can typically be addressed with resolutions of metres, and this is expected to remain largely constant The satellite surveillance and communications systems described here address these requirements

19 Concept of Operations At least some checked-out and calibrated assets held on-orbit to provide opportunities for operator training and the minimum response time in the event of crisis Tactical deployments are very frequent in the ongoing war on terror, so some assets are continuously required Some assets held on ground in complete, (i.e. fully tested), or nearcomplete state to allow optimum orbit deployment, and to deny adversaries the chance to predict their orbits and target them Scope to complete satellites and launch in response to crisis only if components are held at tested sub-system level To assemble and launch a working telescope from sub-components in just a few days implies either:- Significantly degraded performance through uncorrected optical misalignments Manufacturing tolerances that would be prohibitively expensive to achieve Redefining Responsive" #1 Other reasons to keep operational assets on-orbit? No launch risk or delay Covert preparation Assets live as long on orbit as on ground Operational costs very low ($100k per year) compared with ground security costs The opportunity cost is high keeping small satellites (that are state of the art for only 5 years) on the ground for a significant proportion of that period Keeping low-cost assets on orbit is an acceptable risk Theatre selection not compromised Re-orbit capability to lower satellite from higher strategic orbit to provide higher-resolution coverage of the crisis area Tuned orbits with repeat ground traces over the theatre can be established at the onset of a crisis We can anticipate that low inclination orbits are likely to be required for typical trouble spots

20 Increasing Resolution 1990, >1km 1992, 200m 1998, 100m 2000, 30m 2003, 12m 2005, 4m & 2.5m 2009, m 2010, <1m Below 1m Ground Sample Distance 39 Global Mapping Capability SSTL can provide a system that is capable of providing global mapping within 30 months at 0.6 m resolution Commercial Applications Imagery for the multi-billion dollar location-based services market Raw imagery costs $0.15/km 2 (currently sold at $20/km 2 ) Military Applications - Cueing, mapping, GIS data fusion, operational support, mission planning, battle damage assessment, etc. The system includes: An ultra hi-res satellite 16km swath Final product, 0.6m RGB imagery Ground network & systems

21 IR IMAGING At Night! This platform design can also accommodate a MW and LW infrared imager in the same payload volume Baseline GSD at 3-5 microns from 500 km = 10m Baseline GSD at 8-10 microns from 500 km = 15m Schedule to FRR = 36 months Swath = 15 km at nadir STRV-2 MWIR image of Gibraltar showing shipping, cloud features and bathymetry FoV = 1.7 degrees NEDT < K System MTF ~10% at Nyquist Detector: CMT linear array of 1500, 30-micron pixels Cooling to 77K assumed STRV-2 MWIR imager Mid-Wave Infra Red (MWIR) Imager MWIR (3-5µm) camera for detection of aircraft in flight 20cm aperture f/2 optics in zero CTE CFC structure Two images taken 0.7s apart to enable detection of fast moving objects (aircraft) COTS cryocooler proven over 2 years/ 300 images Copyright QinetiQ 2003

22 Launch Concept Constellation-level procurement - RapidEye Commercial contract for RapidEye AG Launched 29 th August 5 enhanced micro-satellites 6.5m metre spatial resolution 5-band multispectral sensor Daily revisit 80 km swath World s First Commercial EO Constellation Commercial in Confidence

23 Odessa in Texas (United States), acquired by CHOROS (RapidEye 4) on Nov The Palm, Jumeirah (Dubai) in red, red-edge and NIR bands acquired by CHOMA (RapidEye 5) on Dec

24 Geolocation Accuracy Requirement to geo-locate images to better than 15m without ground control points All imagers mounted on a thermoelastically stable optical bench Also provides attenuation of microvibration Hardware Under Construction Structural Qualification Models of satellite platform and camera Flight hardware currently under construction Expected launch - late 2009