Download Paul A. Rosen Jet Propulsion Laboratory, California Institute of

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
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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
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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
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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
• 
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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!