nasa-isro sar mission: sensors and potential applications

NASA-ISRO SAR Mission: Sensors and Potential ApplicationsPaul A Rosen, Scott Hensley, Scott Shaffer, Wendy Edelstein, Yunjin Kim, Dankai Liu, Pam Hoffman, Phil Barela, Peter XaypraseuthJet Propulsion Laboratory, California Institute of Technology

Raj Kumar, Tapan Misra, Rakesh Bhan Raju SagiISRO Space Applications Centre ISRO Satellite Centre

Asian Conference on Remote Sensing 2017New Delhi, IndiaOctober 24, 2017

Copyright 2017 California Institute of Technology. Government sponsorship acknowledged.

NISAR Mission Overview

• Major partnership between US National Aeronautics and Space Administration (NASA) and Indian Space Research Organisation (ISRO)

• Baseline launch date: No earlier than December 2020• Dual frequency L- and S-band Synthetic Aperture

Radar (SAR)• L-band SAR from NASA and S-band SAR from ISRO

• NASA 4 Gbps Ka-band telecom system to polar ground stations (> 26 Tbits/day downlink capability)

• ISRO I3K Spacecraft with 2.8 Gbps telecom system• ISRO Geosynchronous Satellite Launch Vehicle

(GSLV) Mark-II (4-m fairing)• 3 years NASA science operations (5+ years

consumables)• All science data (L- and S-band) will be made available

free and openSurface deformation; geo-hazards; water resource management

Ice velocity, thickness; response of ice sheets to climate change and sea level rise

Biomass disturbance; effects of changing climate on habitats and CO2

Ecosystem Structure

Cryosphere

Solid Earth

Mission Science

NISAR Mission Objectives Responsive to US National AcademyKey Scientific Objectives:

• Understand the response of ice sheets to climate change and the interaction of sea ice

and climate

• Understand the dynamics of carbon storage and uptake in wooded, agricultural, wetland,

and permafrost systems

• Determine the likelihood of earthquakes, volcanic eruptions, and landslides

Key Applications Objectives:• Understand societal impacts of dynamics of groundwater, hydrocarbon, and sequestered

CO2 reservoirs

• Provide agricultural monitoring capability in support of food security objectives

• Apply NISAR’s unique data set to explore the potentials for urgent response and hazard

mitigation

To be accomplished in partnership with the Indian Space Research Organisation

(ISRO) through the joint development and operation of a space-borne, dual-

frequency, polarimetric, synthetic aperture radar (SAR) satellite mission with

repeat-pass interferometry capability

ISRO Science and Applications Objectives

NISAR Science & Mission Systems FTM: Jul 10-12, 2017, SAC

1. Ecosystem Structure: 1.1 Agriculture Biomass & Crop Monitoring; 1.2 Forest Biomass; 1.3Biomass Change; 1.4 Mangroves / Wetlands; 1.5 Alpine Vegetation; #Vegetation Phenology andVulnerability; #Vegetation soil moisture; #Ecosystem stress assessment.

2. Land Surface Deformation: 2.1 Inter-seismic / Co-seismic Deformations; 2.2 Landslides; 2.3 LandSubsidence; 2.4 Volcanic Deformations

3. Cryosphere: 3.1 Polar Ice Shelf / Ice sheet; 3.2 Sea Ice Dynamics; 3.3 Mountain Snow/ Glacier 3.4Glacier Dynamics (Himalayan Region); #Glacier hazards; #Climate response to glaciers; #Advisory onsafer marine navigation and sea ice.

4. Coastal Studies & Oceanography: 4.1 Coastal erosion / shoreline change; 4.2 Coastalsubsidence and vulnerability to sea-level rise; 4.3 Coastal bathymetry; 4.4 Ocean surface wind; 4.5Ocean wave spectra; 4.6 Ship detection; #Possible use of SAR for tropical cyclone; #Coastal watchservices

5. Disaster Response: 5.1 Floods; 5.2 Forest Fire; 5.3 Oil Spill; 5.4 Earthquakes / Others

6. Geological Applications: 6.1 Structural & Lithological mapping; 6.2 Lineament mapping; 6.3Paleo-Channel study; 6.4 Geomorphology; #Land degradation mapping; #Geo-archaeology; #Mineralexplorations

NISAR: Proposed Applications

2

NISARNASA-ISRO SAR Mission

NISAR Uniquely Captures the Earth in Motion

NISAR Characteristic: Enables:

L-band (24 cm wavelength) Low temporal decorrelation and foliage penetration

S-band (12 cmwavelength)

Sensitivity to lighter vegetation

SweepSAR technique withImaging Swath > 240 km

Global data collection

Polarimetry(Single/Dual/Quad)

Surface characterization and biomass estimation

12-day exact repeat Rapid Sampling

3 – 10 meters mode-dependent SAR resolution

Small-scale observations

Pointing control < 273arcseconds

Deformation interferometry

Orbit control < 500 meters Deformation interferometry

L/S-band > 50/10% observation duty cycle

Complete land/ice coverage

Left/Right pointing capability

Polar coverage, north and south

NISAR SweepSAR• SweepSAR allows simultaneous

• Wide swath• Fine resolution• polarimetry

• SweepSAR method:• Transmit pulse with full feed illumination• Track echo digitally with individual

receivers (12 at L-band; 24 at S-band)• Assemble individually received signals

into a full-swath measurement

• SweepSAR implemented independently by both JPL and ISRO

• But radars are time-synced for dual-frequency operations

~236 km Earth-fixed ground track spacing at equator for 12-day repeat orbit

NISAR Instrument Overview

Radar Antenna Reflector

Radar Antenna Boom

Radar AntennaStructure

Boom AttachPoint

S-SAR Feed RFAperture

L-SAR Digital Signal Proc Electronics

S-SAR Electronic

s(Inside)

L-SAR RadarInstrument Controller

and RF Back-End(inside)

L-SAR TransmitReceive Modules

Instrument Subsystems:• L-Band SAR (JPL)• S-Band SAR (ISRO)• Instrument Structure (JPL)• Radar Antenna (JPL)

L-SAR Feed RFAperture

Instrument Structure also houses GPS unit and Solid State Recorder

Progress in Development Phase CL-band SAR Hardware (1/2)

Prototype and Pathfinder

TRMs

EM TRM-ESSEM Front-End

Subassembly (FES)TRM Pathfinder EM

EM QFSP

EM RIC-PCU

EM RIC-CTB EM RIC-SIF

EM RBE Stack

EM WaveformGenerator

EM Up ConverterDriver

EM FrequencySynthesizer EM RBE-PCU

EM RIC-HKT

EM SSP

Digital Signal Processor

RIC- RAD750 QualModel

FM RIC-NVM (SEAKR)

Progress in Development Phase CL-band SAR Hardware (2/2)

Feed Tile EM(without radome)

Boom and Hinge Development Hardware

10” Development Boom Stability Test

7” Prototype Boom/Hinge in fabrication

Hinge Deploy & Latching H/W

PT Spring Assemblies

Boom Harness Torque Test

Boom Actuator PT

L-FRAP Feed Tile Development Hardware

Hinge Spring Cartridge Torque Test

Feed Array EM in Test

Prototype 7” Spring/Damper Deploy Test

Front-end Radiating Aperture S-band Development and Joint L+S compatibility

NISAR Project Assessment Meeting @ ISAC – 13th July 2017 S-SAR Development Status- 4

SFRAp Development

• S-FRAp DVM – Delivered• Radiation pattern characterization of DVM S-FRAp with JPL L-FRAp - Complete• QA approval of QM S-FRAp drawings (Elec. & Mech.) - In progress

• PT 210 Cable delivery confirmed by vendor

• Fabrication process qualification – in progress

• Multipaction test on 1/3 antenna tile – in progress

• QA Clarence - torqueing on TNC connector

• Bending radius relaxed to 60mm

DVM Antenna TilesS-band

L-band aperture

L+S structure

NISAR Observatory

NISAR Imaging and Orbit Geometry74

7 km

Earth surface

Observation Geometry

>240 km

12 m diameter Reflector

33o

47o 6 AM / 6 PM Orbit98.5o inclinationArctic Polar Hole: 87.5R/77.5LAntarctic Polar Hole: 77.5R/87.5L

• Wide swath in all modes• Data acquired ascending and descending• Left/right pointing capability

NISAR Systematic ObservationsL-band globally – S-band regionally

Repeated every 12 day cycle for the life of the mission

Planned launch: 2021

C. Ballard, JPL

No target conflicts: overlapping targets uses union of all modes specified

Persistent updated measurements of Earth

Colors indicate different radar modes

Note: conceptual plan – does not reflect current detailed plan

ISRO Targets over India and Surroundings

NISAR Science & Mission Systems FTM: Jul 10-12, 2017, SAC

India + neighbors boundary

Agriculture/ Forest/ wetland

Jute crop

Alpine forest

Seismic Deformation

Land Subsidence

Landslide

Urban subsidence

Volcanic deformation/ studies

Coastal region (sea 300km)

Coastal habitat

Coastal deformation

Coastal mud bank

Coastal region (land, 100 km)

Ocean – Arabian Sea

Ocean – Bay of Bengal

Disaster – floods

Disaster – forest fire

Disaster – oil slick

Cryosphere - Himalayas

ISRO Targets over India and SurroundingsThese exclude polar targets

Arabian Sea

Bay of Bengal

Forest Fire

Land Subsidence

Oil Slick

Agril.Forest

Wetland

SnowGlacier

Mud bank

Coastal Habitat

Volcano

Urban

4

NISAR Science Observing/Operations ModesBlanket Land and Ice Coverage Every 12 Days

• Observation strategy employs a subset of possible modes

Observation Strategy L-band S-band Culling ApproachScience Target Mode+ Resolution Mode Resol. Sampling Desc Asc

Background Land DP HH/HV 12 m x 8 m cull by lat

Land Ice SP HH 3 m x 8 m cull by lat

Sea Ice Dynamics SP VV 48 m x 8 m s = 1 p

Urban Areas 6 m x 8 m s = 1 p

US Agriculture QP HH/HVVV/VH

s = 1 p

Himalayas CP RH/RV s = 1 pIndia Agriculture s = 1 p

India Coastal Ocean DP HH/HV orVV/VH

s = 1 p

Sea Ice Types DP VV/VH s = 3 p 15

NISAR Radar Modes

BW PRF PW Swath L-SAR S-SARL-DataRate

S-DataRate

(MHz) (Hz) [µ sec] [km] DC[W]+ DC[W]# [Mbps] [Mbps]#128 L1 L DPHH/HV 20+5 1650 25 242 1406 635 893 -

129 L QQ 20+5 1650 25 242 635 -

130 L QQ 20+5 1650 20 242 635 -131 L2 L SPHH 80 1650 40 121 1426 635 706 -132 L SPHH 40+5 1650 45 242 635 -133 L SPHH 20+5 1650 25 242 635 -134 L3 L SPVV 5 1600 25 242 1355 635 91 -135 L QDHH/VV 5+5 1650 20 242 635 -136 L4 IndiaLandCharacterization L DPVV/VH 20+5 1650 25 242 635137 L5 L DPHH/HV 40+5 1650 45 242 1495 635 1627 -138 L QQ 40+5 1650 45 242 635 -139 L QQ 40+5 1650 40 242 635 -140 L6 USAgriculture,IndiaAgriculture L QPHH/HV/VH/VV 40+5 1600* 45 242 1683 635 3156 -141 LX USAgriculture,IndiaAgricultureLowRes L QPHH/HV/VH/VV 20+5 1600* 45 242 1683 635 3156 -142 L7 ExperimentalCPmode L CPRH/RV 20+20 1650 40 242 635 -143 L8 ExperimentalQQmode L QQ 20+20 1650 20 242 635 -144 L9 ExperimentalSPmode L SPHH 80 1650 20 242 635 -145 ISROIce/sea-ice L DPVV/VH 5 1650 25 242 635 -146 ISROIce/sea-ice-alternate L QDHH/VV 5 1650 25 242 635 -

64 S1 SolidEarth/Ice/Veg/Coast/Bathym S Quasi-Quad 37.5 2200 10+10 244 1201 1604 - 371465 S2 Ecosystem/CoastalOcean/Cryosphere S DPHH/HV 10 2200 25 244 1201 1836 - 62666 S3 Agriculture/SeaIce S CPRH/RV 25 2200 25 244 1201 3020 - 124267 S4 GlacialIce-HighRes S CPRH/RV 37.5 2200 25 244 1201 3020 - 185768 SX Newmode S DPHH/HV 37.5 2200 25 244 1201 3020 - 185769 S5 Deformation S SPHH(orSPVV) 25 2200 25 244 1201 1563 - 62070 S6 Deformation-MaxRes S SPHH(orSPVV) 75 2200 25 244 1201 1563 - 1857

UrbanAreas,HimalayasSMUrbanAreas,HimalayasSMHiPwr

OpenOcean

LowDataRateStudyModeSinglePolLandIceLowRes

Science Performance Resources

FreqBand

PolarizationConfig.ID

LandIce

BackgroundLand

SeaIceDynamics

UrbanAreas,Himalayas

PrimaryScienceTarget

BackgroundLandSoilMoisture

BackgroundLandSoilMoistureHiPwr

OldMode#


S-DataRate


129 L QQ 20+5 1650 25 242 635 -



DPHH/HV 20+5 1910^ 25 242CPRH/RV 25 25 244DPHH/HV 20+5 1910^ 25 242DPHH/HV 37.5 25 244DPHH/HV 20+5 1910^ 25 242

SPHH(orSPVV) 25 25 244SPVV 5 1910^ 25 242

DPVV/VH 10 25 244L:DPVV/VH 20+5 1910^ 25^ 242S:CPRH/RV 25 25 244L:DPHH/HV 40+5 1910^ 45^ 242S:CP/RH/RV 37.5 25 244L:DPHH/HV 40+5 1910^ 45^ 242

S:SPHH(orSPVV) 75 25 244L:QPHH/HV/VH/VV 40+5 1550*^ 45^ 242

S:CPRH/RV 25 3100 10' 244L:QPHH/HV/VH/VV 40+5 1550*^ 45^ 242

S:DPHH/HV 37.5 3100 10' 244L:QPHH/HV/VH/VV 20+5 1550*^ 45^ 242

S:CPHH/HV 25 3100 10' 244

L:QPHH/HV/VH/VV 20+5 1550*^ 45^ 242

S:DPHH/HV 3100 10' 244

DPVV/VH 5 1910^ 25 242

CPRH/RV 25 25 244

DPVV/VH 5 1910^ 25 242

DPVV/VH 10 25 244

201 LX+S3 Coastal-X L+S

202 LX+SX Coastal-X L+S

203 L?+S3 ISROIce/sea-ice L+S

204

192

SystematicCoverage&Deformation L+S193

L+S


OpenOcean

L+S

L1+S3

L1+S4

L1+S5

L3+S2

L6+SX

L+S



SystematicCoverage

FreqBand


198 L+S

L?+S2 ISROIce/sea-ice-JjointAlternate

LandIce

BackgroundLand

SeaIceDynamics



194 Coastal-Mudbank(wetsoil????)

199 IndiaAgriculture



195 Ocean

200 Coastal-Land

197 GlacialIce-Himalayas L+S 1528 2710

OldMode#

196 SeaIceTypes L+S 1033

L+S 1670 1990

L4+S3

L5+S4

L5+S6

L6+S3

High-ResDeformation(Disaster/UrgentResponse)

L+S

1078

L+S

1610

3057 1754

1528 1407 1883

1425 2710

1883 1616

NISAR Joint Radar Modes


S-DataRate


129 L QQ 20+5 1650 25 242 635 -



DPHH/HV 20+5 1910^ 25 242CPRH/RV 25 25 244DPHH/HV 20+5 1910^ 25 242DPHH/HV 37.5 25 244DPHH/HV 20+5 1910^ 25 242

SPHH(orSPVV) 25 25 244SPVV 5 1910^ 25 242

DPVV/VH 10 25 244L:DPVV/VH 20+5 1910^ 25^ 242S:CPRH/RV 25 25 244L:DPHH/HV 40+5 1910^ 45^ 242S:CP/RH/RV 37.5 25 244L:DPHH/HV 40+5 1910^ 45^ 242

S:SPHH(orSPVV) 75 25 244L:QPHH/HV/VH/VV 40+5 1550*^ 45^ 242

S:CPRH/RV 25 3100 10' 244L:QPHH/HV/VH/VV 40+5 1550*^ 45^ 242

S:DPHH/HV 37.5 3100 10' 244L:QPHH/HV/VH/VV 20+5 1550*^ 45^ 242

S:CPHH/HV 25 3100 10' 244

L:QPHH/HV/VH/VV 20+5 1550*^ 45^ 242

S:DPHH/HV 3100 10' 244

DPVV/VH 5 1910^ 25 242

CPRH/RV 25 25 244

DPVV/VH 5 1910^ 25 242

DPVV/VH 10 25 244

201 LX+S3 Coastal-X L+S

202 LX+SX Coastal-X L+S

203 L?+S3 ISROIce/sea-ice L+S

204

192

SystematicCoverage&Deformation L+S193

L+S


OpenOcean

L+S

L1+S3

L1+S4

L1+S5

L3+S2

L6+SX

L+S



SystematicCoverage

FreqBand


198 L+S

L?+S2 ISROIce/sea-ice-JjointAlternate

LandIce

BackgroundLand

SeaIceDynamics



194 Coastal-Mudbank(wetsoil????)

199 IndiaAgriculture



195 Ocean

200 Coastal-Land

197 GlacialIce-Himalayas L+S 1528 2710

OldMode#

196 SeaIceTypes L+S 1033

L+S 1670 1990

L4+S3

L5+S4

L5+S6

L6+S3

High-ResDeformation(Disaster/UrgentResponse)

L+S

1078

L+S

1610

3057 1754

1528 1407 1883

1425 2710

1883 1616

NISAR Noise Performance of 20 MHz DP Mode

Slide 18

• Assumes fixed PRF

Transmit blanking gaps

Multiplicative Noise with Varied PRF at Dual Pol

Slide 19

Staggered SAR – Quad Pol

NESZ ASR

Mean PRF = 2 X 1600 Hz

NISAR Level-2 Solid Earth Science Requirements Summary

Attribute Secular Deformation (658) Co-Seismic Deformation (660) Transient Deformation (663)

Measurement Spatially averaged relativevelocities in two dimensions

Point-to-point relative displacements in two dimensions


Method Interferometry, Speckle tracking Interferometry, Speckle tracking Interferometry, Speckle tracking

Duration 3 years 3 years Episodic over mission, depending on science target

Product resolution

100 m; smoothed according to distance scale L

100 m 100 m

Accuracy 2 mm/yr or better,0.1 km < L < 50 km, over > 70% of coverage areas

4 (1+L1/2) mm or better, 0.1 km < L < 50 km, over > 70% of coverage areas

3 (1+ L1/2) mm or better, 0.1 km < L < 50 km,over > 70% of ~2,000 targeted sites

Sampling One estimate over 3 years, two directions

4 times per year to guarantee capture of any earthquake on land before surface changes too greatly

Every 12-days, two directions

Coverage Land areas predicted to move faster than 1 mm/yr

All land, as earthquake locations are unknown a priori

Post-seismic events, volcanoes, ground-water, gas, hydrocarbon reservoirs, landslide-prone

Response latency

N/A 24 hour tasking, 5 hour data deliveryBest effort basis on event

24/5Best effort basis on event

NISAR Level-2 Cryosphere ScienceRequirements Summary (1/2)

Attribute Ice Sheets and Glaciers VelocitySlow Deformation (667)

Ice Sheets and Glaciers VelocityFast Deformation (668)

Ice Sheet Time-Varying Velocity (738)

Measurement Point-to-point displacements in two dimensions

Point-to-point displacements in two dimensions

Point-to-point relative horizontal displacements

Method Interferometry, Speckle tracking Interferometry, Speckle tracking Interferometry, Speckle tracking

Duration 3 years 3 years 3 years

Product resolution

100 m 250 m 500 m

Accuracy 3% of the horizontal velocity magnitude plus 1 m/yr, or better, over > 90% of coverage areas

3% of the horizontal velocity magnitude plus 5 m/yr, or better, over > 90% of coverage areas

3% of the horizontal velocitymagnitude plus 10 m/yr, or better,over > 80% of coverage areas

Sampling Each cold season, two directions Each cold season, two directions Every 12-days, two directions

Coverage Areas moving slower than 50 m/yr of both poles and glaciers and icecaps

Areas moving faster than 50 m/yr ofboth poles

Outlet glaciers, or other areas of seasonal change

Response latency

N/A N/A 24/5Best effort basis on event

NISAR Level-2 Cryosphere ScienceRequirements Summary (2/2)

Attribute Permafrost Displacement(671)

Grounding Line Vertical Displacement (445)

Sea Ice Velocity (670)

Measurement Spatially averaged relativevelocities in two dimensions


Point-to-point relative horizontal displacements

Method Interferometry Interferometry Backscatter image feature tracking

Duration 3 years 3 years 3 years

Product resolution

100 m 100 m Gridded at 5 km

Accuracy 10 mm or better,over > 80% of coverage areas

100 mm or better,over 95% coverage areas annuallyover 50% coverage areas monthly

100 m / day,over 70% of coverage area

Sampling In snow-free months sufficient to meet accuracy (semi-monthly)

Monthly Every 3 days

Coverage Targeted priority regions in Alaska and Canada

Greenland and Antarctic coastal zones

Seasonally-adjusted Arctic and Antarctic sea ice cover

Response latency

N/A 24 hour tasking, 5 hour data deliveryBest effort basis on event


NISAR Level-2 Ecosystem Science Requirements Summary

Attribute Biomass (673) Disturbance (675) Inundation (677) Crop Area (679)

Measurement Biomass Areal extent Areal extent Areal extent

Method Polarimetric backscatter to biomass

Polarimetric backscattertemporal change

Polarimetric backscattercontrast

Polarimetric backscatter contrast and temporal change

Duration 3 years 3 years 3 years 3 years

Product resolution

100 m 100 m 100 m 100 m

Accuracy 20 Mg/ha or better where biomass is < 100 Mg/ha, over 80% of coverage areas

80% or better classification accuracywhere canopy cover changes by > 50%

80% or better classification accuracy

80% or better classification accuracy

Sampling Annual Annual Seasonal, sampled every 12 days to track beginning and end of flooding events

Quarterly; sampled every 12 days to track beginning and end of growing season

Coverage Global areas of woody biomass

Global areas of woody biomass

Global inland and coastal wetlands

Global agricultural areas

Response latency

N/A 24/5Best effort basis on event


N/A

End-to-End Science Measurement Performance Simulations for Deformation and Biomass

Radar SensorPerformance

Tool

MissionScenario

Tool

SAR/InSARPerformance

Tool

Radar Parameters

Data Types

EphemerisGeneration

Tool

Power, gain, BW, etc.

Backscatter typeSlope

Con Ops RulesData prioritiesObservation timelines

Mission ConstraintsPowerData rate/volumeDownlink masks

Radar PerformanceSNRAmbiguitiesQNRISLRAzimuth resolutionRange resolutionEtc.

Observation ListTimes points observedPlatform locationRadar modeIncidence angle

Data Masks

L1 and L2 Parameter Performance MetricsDeformation errorBiomass error

Troposphere (seasonal)Ionosphere (time of day)Snow cover (8-day sampling)Terrain classification mapDEM and DEM slopeGlobal tree height map

MPREFOBS307f Solid Earth Analysis Summary

Category Coverage Req.

Coverage Est.

Uncertainty Req.

Uncertainty Est.

Status

Level 1 in mm

70% 82.3% 3.5 * (1+sqrt(L))

2.96 * (1+sqrt(L))

OK - OK

Coseismic (660) in mm

70% 80.9% 4 * (1+sqrt(L))

3.05 * (1+sqrt(L))

OK - OK

Transients (663) in mm

70% 85.7% 3 * (1+sqrt(L))

2.56 * (1+sqrt(L))

OK - OK

Active (658) in mm/yr

70% 99.6% 2 1.63 OK - OK

0.1 km < L < 50 kmMeets requirements with > 10% marginMeets requirements with < 10% marginDoes not meet requirements

MPREFOBS 307f Biomass Performance Results: 5-Class Backscatter-to-Biomass Model

0 20 40 60Biomass Retrieval Error (Mg/ha)

Histo

gram

Cou

nt

• Points where retrievals were attempted: 21,674

• Points with biomass < 100 Mg/ha: 14,272

• Such points with error < 20 Mg/ha: 13,526

• Percent of such points meeting error threshold:

13,526/14,272 = 94.8% (requirement is 80%)

• Assumes geographically-dependent surface

backscatter variability and 0.5 dB calibration

uncertainty, 5-class backscatter-to-biomass model

Biom

ass R

etrie

val E

rror (

Mg/

ha)

5.2%94.8%

Biomass Performance Model predicts NISAR meets its biomass requirements

Summary

• NISAR Mission now in development, planning for launch in 2021

• Project has demonstrated it can meet mission science performance requirements using fixed PRF observations

• Transmit blanking gaps are not desirable to scientists, but schemes to mitigate raise ambiguity noise

• Current algorithmic efforts seek to understand impacts on science performance, and develop mitigation schemes

nasa-isro sar mission: sensors and potential applications

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