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GSHAP L. Wood, P. Worfolk et al., SaVi - Satellite constellation Visualisation software, http://savi.sf.net/, 2010. Paul A. Rosen Jet Propulsion Laboratory, California Institute of Technology UNAVCO Workshop Boulder, Colorado March 10, 2010 Outline • • • • • Background Planned International Radar Missions DESDynI (NASA) Data Access Summary The Solid Earth Science Working g Group p Report p Recommendations The Solid Earth Science Working g Group p Report p Recommendations 1-5 years The Solid Earth Science Working g Group p Report p Recommendations 5-10 years The Solid Earth Science Working g Group p Report p Recommendations 10+ years SAR/InSAR Earth Missions Toward Realizing SESWG SeaSAT SIR-A Challenger SIR-C/ X-SAR RB SIR-B DESDynI SRTM ERS-1 Envisat-1 Sentinel 1a/b ERS-2 JERS-1 ALOS RADARSAT-1 ALOS-2 RADARSAT-2 TerraSAR-X TanDEM-X Cosmo-Skymed 1980 1985 1990 1995 From: Rosen and Buccolo (2007) IEEE Radar Conference 2000 2005 2010 2015 And yet… • Current SAR satellite capabilities continue to have their limitations – – – – Non-uniform and limited coverage Monthly sampling Coherence issues Commercialization • (Data access in general is improving greatly, though) • The next generation of InSAR systems will need to address these issues Next Generation InSAR-Capable Systems System Agency Sentinel-1A/ 1B ESA (2012) 2 12-day/6-day C Multiple, primary: wideswath InSAR ALOS-2 JAXA (2013) 1 14-day L Multiple 3 12-day/4-day C Multiple Radarsat CSA Constellation (2014-15) # of birds Repeat Period Band Modes DESDynI NASA (2017) 1 8-day L Multiple, primary: wideswath Pol/InSAR SAOCOM-1 A/1B CONAE (2013) 2 16-day/8-day L Multiple TerraSAR-N DLR (?) ? ? X Commercial Many others … Sentinel-1 Concept • Space component of the EU/ESA initiative on Global Monitoring for Environment and Security (GMES) • Driven by ‘end’ user requirements not by Earth observation research – Marine Services – Land Monitoring Services – Emergency/Disaster • Frequent observations • Operational • Emphasis on information products (Sampling using Two Satellites) From: Sentinel-1 The Radar Mission for GMES Operational Land and Sea Services (2007), Attema et al. Sentinel-1 Operating Modes From: The GMES Space Component perspective, 4-th e-collaboration workshop, ESRIN 25 Feb 2009 Sentinel-1 Characteristics • Lifetime: 7 years (consumables 12 years) • Orbit: near-polar Sun-synchronous 693 km; 12-day repeat cycle; 175 revs per cycle • Mean Local Solar Time: 18:00 at ascending node • Orbital period: 98.6 minutes • Orbit knowledge: 10 m (each axis, 3-sigma) using GPS • Operating autonomy: 96 hours • Spacecraft availability: 0.998 • Science data storage capacity: 900 Gb (end-of-life) • X-band data rate: 600 Mbit/s From: Sentinel-1 The Radar Mission for GMES Operational Land and Sea Services (2007), Attema et al. ALOS-2 Overview - Continue the ALOS mission with enhanced performance - Comprehensive land monitoring (land infrastructure management, resource management and resource exploration) - Provide timely observation [day time <3 hours and night time <6 hours (80%) by adding foreign satellites] with high resolution [1–3 m] and wide coverage [50 km] for disaster management in Japan, and contribute to the international disaster management - Pathfinder of potential use by enhanced performance ALOS-2 target specification ALOS-2 – L-band SAR – Spotlight, Stripmap, ScanSAR mode – Right- and left-looking by spacecraft maneuvering – Single , Dual, Compact and Full polarimetry From: S. Suzuki (2009), ISTS 2009 Parameter Value RF band L-band RF band width 85MHz Weight SAR : approx. 640kg Spacecraft : approx. 2 tons SAR antenna size 3m (El) * 10m (Az) Active phased array antenna SAR data compression 2 or 4 bit (raw data 8 bit) Data transmission rate DT [X-band] : 840M/420Mbps Data relay [Ka-band]: 278Mbps Max. transmission power 4000 - 6000W Observation duty 30 % per orbit Launch Early 2013 ALOS-2 SAR observation modes SAR observation modes and performance (*!" +-("/"-",0") 3 ) %!")/)#'" )!2%!/$ # ". 4 2/$ *'-%("/-3 # 4 /-%+(+ %#$".*'0/%*) +*/'%#$/ 4 ( ( &(#&(546 .%)#'" ! ! ! 4 ( ( &( .%)#'"!0' ! ! ! /-%+(+ %#$").%/%1%/3 4 /*!"#-"" 4 ( ( &( .%)#'"!0' ! ! ! /-%+(+ *)1")/%*)' 4 ( ( &( .%)#'"!0' ! ! ! ) 4 ( ( &( .%)#'"!0' ! ! ! CP: Compact Polarimetry, FP: Full Polarimetry (HH+HV+VV+VH) Performance @ incident angle 37deg 160km round nadir a no obs 70° 8° 350 km 8° 50 km 70° Spotlight ScanSAR Stripmap Observation area 25 km×25km From: Y. Kankaku (2009) PIERS Proceedings, Moscow, Russia, August 18-21, 2009 RCM Observational Characteristics • Daily coverage of Canada's inland, territorial and adjacent waters to support maritime surveillance, including ice monitoring, marine wind monitoring, oil pollution monitoring and ship detection; • Ability to image any disaster location in the world within 24 hours to establish the state of critical infrastructure; • Ability to monitor all of Canada for disaster mitigation on a regular basis (monthly to twice-weekly) to assess risks and identify damage prone areas; and, • Regular coverage of Canada's land mass and inland waters, up to several times weekly in critical periods, for resource and ecosystem monitoring • • • • • 3 satellites equally-spaced in a dawn-dusk plane Antenna - 9.45m2 Power - < 1600 W (peak); < 220 W (average) Orbit - 600 km, 100 m radius orbital tube Polarisation - Dual cross selectable pol on all low and medium resolution modes; "experimental" quad pol • Imaging Time - 12 minutes/orbit (peak 20 minutes every three orbits) 10 minutes continuous imaging • Lifetime - 7 years (each satellite) http://www.asc-csa.gc.ca/eng/satellites/radarsat/description.asp http://www.asc-csa.gc.ca/eng/satellites/radarsat/description.asp Recommended by the NRC Decadal Survey for near-term launch to address important scientific questions of high societal impact: What drives the changes in ice masses and how does it relate to the climate? How are Earth’s carbon cycle and ecosystems changing, and what are the consequences? How do we manage the changing landscape caused by the massive release of energy of earthquakes and volcanoes? Ice sheets and sea level Will there be catastrophic collapse of the major ice sheets, including Greenland and West Antarctic and, if so, how rapidly will this occur? What will be the time patterns of sea level rise as a result? Shifts in ecosystem structure and function in response to climate change How will coastal and ocean ecosystems respond to changes in physical forcing, particularly those subject to intense human harvesting? How will the boreal forest shift as temperature and precipitation change at high latitudes? What will be the impacts on animal migration patterns and invasive species? p Extreme events, including earthquakes and volcanic eruptions Are major fault systems nearing release of stress via strong earthquakes Eruptive state of volcanoes? Planned by NASA as one of the following 4 Decadal Survey TIER 1 Missions SMAP ICESat-II DESDynI CLARREO Deformation Biomass Ice Dynamics Polarimetric SAR Multibeam LIDAR Canopy py Height Heigh g t Biomass Vegetation Structure Vegetation Disturbance Sea Ice Thickness Biomass Effects of changing climate on habitats and CO2 Repeat Pass InSAR Pass 1 DESDynI will exploit an L-band polarimetric radar operated interferometrically (InSAR) and multibeam lidar Pass 2 Response of ice sheets to climate change & sea level rise Sea Ice and Ice Sheet Dynamics Changes in Earth’s Surface Geo-Hazards Common theme in these three disciplines, reflected in mission requirements: Need for finer spatial and temporal sampling DESDynI will join the international fleet of missions to deliver suitable sciencedriven observations with sufficient coverage and sampling Mission Characteristics fulfilling these needs: • Multi-year (3/5) mission to observe global scale change • L-band synthetic aperture radar (SAR) system - Frequent (8-day) revisit to observe fast processes - Repeat-pass Interferometer (InSAR) for mm-scale accuracy - Multiple polarization for hectare scale biomass and change - Viewable swath of 360 km for complete global coverage at 8 days - 10 m intrinsic ground resolution • Multiple-beam (5) lidar - Operating in the infrared (1,064 nm) for sensitivity to canopy - 25-m spatial resolution per beam sampled along-track every 30 m - Sub-meter vertical profiles within 25-m footprint - 250 m resolution grid after 5 years 19 19 Science Requirement Measurement Requirement Instrument Requirement Ecosystem Structure • Global Biomass/Carbon • Global Biomass Change • Global Biodiversity • Canopy height and structure metrics accurate to 1 m accuracy (0° slope) at 250-500 m spatial resolution in 5 yrs • Biomass at 100 m spatial resolution in low biomass areas • Forest change maps, annually • 5-beam profiling lidar operated at near nadir incidence, 25 m profile resolution, • Lidar 91-day repeat orbit • Quad-pol L-band radar operating in 30-46° incidence angles at 10 m resolution, seasonally Dynamics of Ice • Ice sheet dynamics • Glacier dynamics • Sea ice dynamics • 2-D velocity accurate to 1 m/yr at 100 -500 m spatial resolution over ice sheets and glaciers, 5 yrs • DEM topography accurate to 1 m at 1 km spatial resolution over ice sheets and glaciers • Elevation precise to 3 cm at 25 m profile resolution over sea ice • 5-beam profiling lidar operated at near nadir incidence, 25 m profile resolution • Lidar 91-day repeat orbit • L-band radar operating in 8-day repeat period orbit, global accessibility, at 10 m resolution, continuously over mission • Left/Right pointing Deformation • Tectonic processes • Magmatic processes • Sequestration, landslides, and aquifer change • 2-D deformation rates accurate to 1 mm/yr over 50 km length scale at 100-1000 m spatial resolution • 2-D deformation accurate to 5-20 mm over 50 km length scale at 100 m resolution, weekly sampling • L-band radar operating in 8-day sampling period orbit • Global accessibility • 10 m resolution • All continuously over mission • Left/Right pointing Interseismic strain accumulation at diffusive plate boundary deformation zone An accuracy of 1 mm/yr is needed to study interseismic strain accumulation, plate boundary deformation e.g., Northern metropolitan Los Angeles is shortening at 5 mm/yr. Strain is building up above the Puente Hills Thrust fault. Argus et al. 2005 5 mm/yr projected onto InSAR line of sight is 2 mm/yr. Donald Argus • "% # "% !& # • & & %! " % % % " !& & # " Zhen Liu Accuracy improvement by stacking in time Troposphere delay is uncorrelated over several days. If rate is constant, stacking interferograms improves accuracy Stacking interferograms generated every 24 days improves InSAR accuracy to: 1.0 mm/yr 5 year mission 2.2 mm/yr 3 year mission (standard error, horizontal distance 50 km). generated every 8 days 0.6 mm/yr 5 year mission 1.3 mm/yr 3 year mission Donald Argus 761 km altitude 8-day repeat at Descending Track Right (Starboard) Pointing Incidence angles 30-50 degrees 36 km 360 Swath Sw 360 km Adjacent Equatorial Ground Track Separation Ascending Track Right (Starboard) Pointing Incidence angles 30-50 degrees NOTE: NOT TO SCALE! 360 60 km wath Swath 761 km altitude 8-day repeat 360 km Adjacent Equatorial Ground Track Separation 761 km altitude 8-day repeat Descending Track Left (Port) Pointing Incidence angles 30-50 761 km altitude 8-day repeat 360 kkm Swath 360 km Adjacent Equatorial Ground Track Separation Ascending Track Left (Port) Pointing Incidence angles 30-50 degrees 360 km Swath NOTE: NOT TO SCALE! 360 km Adjacent Equatorial Ground Track Separation 2 observations (1 ascending, 1 descending) in an 8-day cycle Descending Left-Looking coverage shown: Ascending • Plan is to acquire this map every cycle • Yearly data volume for Solid Earth Science: 163 TB 26 Assumes freedom to point left or right at will to target a particular observation Mean Access Interval (Days) ∞ 4 2 1.3 1 Steven Hu, JPL The DESDynI Mission will produce a wide range of products for three distinct science communities Global Ice Global Biomass Tectonic and Volcanic Active Regions Observation Targets (Colored) Some Product Characteristics: • 2-D deformation maps of ice sheets - Complete coverage yearly, 100 – 1000 m resolution, l ti 11 5 m /yr / accuracy • 2-D sea-ice motion at both poles - Weekly polar coverage, 5-km resolution, 100 m / day accuracy • Biomass and biomass change - Global coverage yearly, 100-1000 m resolution, accuracy of better than 20% • 2-D deformation maps of Earth’s most severe geohazards - Weekly to yearly over Earth’s deforming margins, 20 – 100 m resolution, accuracy from mm – cm / yr • Sea-ice thickness - Monthly-yearly polar coverage, 25 km resolution, better than 60 cm accuracy 28 15 m mesh reflector Stowed for Launch in EELV Fairing 4.7 m nd L-ba ric R Po et larim eed rF ada Strip-mode SAR Standard SAR mode Send a pulse of energy; receive echo; repeat StripSAR One pulse transmit and receive at a time Swath width limited by radar ambiguities ScanSAR Wider swath low resolution SAR mode Execute sequence as follows: ♦ ♦ ♦ ♦ ♦ Send a pulse of energy; receive echo; repeat 50-100 times Repoint the beam across-track to position 2 electrically (almost instantaneous) Send a pulse of energy; receive echo; repeat 50-100 times Repoint the beam across-track to position 3 electrically (almost instantaneous) Send a pulse of energy; receive echo; repeat 50-100 times Again, one pulse transmit and receive at a time ScanSAR trades resolution (in along-track dimension) for swath: low impact on data rate Generally poorer ambiguity and radiometric performance than Strip SAR ScanSAR 30 What A is SweepSAR? Transmit pulse over wide beam in elevation Receive echo over narrow beam tracking echo with scanning receive e beam Can require multiple simultaneous receive beams to track multiple echoes completely new capability Solves the traditional large, complexx antenna problem with a large passive ve reflector and compact digital feed electronics Breaks the standard SAR performance nce limits by separating transmit and receive apertures with digital beamforming techniques SweepSAR achieves very high h area coverage rates at fine, selectable resolutions, full polarization 31 • DESDynI is in the formulation phase (pre-Phase A) - Radar satellite and instrument being designed by JPL - Lidar satellite and instrument being designed by GSFC • Level 1 Science Requirements have been drafted by Steering Group in preparation for Mission Concept Review (MCR) • Designs for Radar and Lidar spacecraft and Operations Concept meeting these L1 requirements are reaching maturity for MCR • Current plan is to enter Phase A in FY11 • President’s budget seeks to accelerate all Decadal Survey Mission, including DESDynI 32 Mission Operations Concept Data Distribution Data Policy Method Sentinel-1A/1B One mode: InSAR Wide Swath, but where? Cloud Storage and Distribution; details TBD Free and Open Access; details TBD ALOS-2 Campaign; disasters Data Nodes?** Toward Commercial** Radarsat Constellation Canada-centric; disasters AO driven? New Data Distribution Model DESDynI Systematic Science Observations; disasters Science Nodes; exploring cloud technologies Free and Open Access ** Observation Plan similar to ALOS-1 is likely And there will be other missions as well providing data • There is a new generation of radar satellites being designed to deliver unprecedented quantities of SAR data • This gives a great potential for the InSAR research community to have the kind of data it has been requesting for years – – – – Fast-repeat Global Unrestricted Geodetic-grade • Whether these data can be used to realize the InSAR potential will depend on many factors, especially data acquisition strategy and data policy • Sentinel-1A/1B, albeit at C-band, and possibly other systems seem to be poised to deliver useful data • DESDynI is being designed specifically to realize this potential • “InSAR Everywhere, All the Time” is fast approaching!