Basal Ice Imaging Radar

Byrd Polar Research Center, The Ohio State University

Jet Propulsion Laboratory

Wallops Flight Facility

Remote Sensing Solutions

Electroscience Laboratory, The Ohio State University

University of Iowa

Concept Overview

February 6, 2009Imaging Greenland and Antarctica as they would appear stripped of their icy cover

Ice Sheet Mass Balance and Sea Level• Ice sheet mass balance is described by the mass continuity equation

Altimeters

InSAR

Act/Pass. Microwave

Obtaining ice thickness data around the perimeter of the ice sheets remains a primary goal of the ice sheet science community (ISMASS)

aUHdt

dh

Evaluations of the left and right hand sides of the equation will yield a far more complete estimate of the current contribution of ice sheets to sea level rise. Moreover, unique, 3-d imagery of the base will substantially improve ice dynamics modeling enabling better predictions of the future response of ice sheets to global climate change

Science Requirements• 2 m vertical ice sheet surface height accuracy

– across the radar swath • 10 cm vertical ice sheet surface height

accuracy – along laser scan for radar calibration and comparison with ICEsat

• 20 m vertical ice sheet base height accuracy for all ice covered terrain

• 20 m vertical accuracy on radar internal layers for ice dynamics

• 25 m geolocation accuracy (WGS 84/polar stereographic projections)

• Relative radiometric accuracy sufficient to discriminate basal rock from basal water

• 50 m pixels• Continuous coverage with 100 km swath from

grounding lines for both Greenland and Antarctica.

• Capability for 5-10 year repeat of integrated measurements for mapping redistribution of subglacial water (post Ventures addition to baseline measurement of topography)

• Data products to be integrable with DESDynI surface velocities and ICEsat surface topography

1st UHF image of ice sheet surface

Team Organization

PI (Ken Jezek) PI (Ken Jezek)

LIDAR(B. Krabill)

LIDAR(B. Krabill)

WISE(A. Safaeinili)

WISE(A. Safaeinili)

Science teamErnesto Rodriguez - interferometryWilliam Krabill - Surface elevation changeDavid Holland - ocean-ice sheet modelingChristina Hulbe - numerical ice sheet modelingRichard Hindmarsh - ice dynamics modelingJoel Johnson – radar scattering modeling

Science teamErnesto Rodriguez - interferometryWilliam Krabill - Surface elevation changeDavid Holland - ocean-ice sheet modelingChristina Hulbe - numerical ice sheet modelingRichard Hindmarsh - ice dynamics modelingJoel Johnson – radar scattering modeling

Payload system engineering (G.

Sadowy)

Payload system engineering (G.

Sadowy)

Project management

(TBD)

Project management

(TBD)

GISMO(X. Wu) GISMO(X. Wu)

Radar (B. Heavy, JPL)VHF Antennae (Volakis & Chen, OSU)

Low Frequency Antenna (Kurth, Kirchner, Iowa)

Digital subsystem (Carswell,Moller, RSS)

Radar (B. Heavy, JPL)VHF Antennae (Volakis & Chen, OSU)

Low Frequency Antenna (Kurth, Kirchner, Iowa)

Digital subsystem (Carswell,Moller, RSS)

System operations

(RSS)

System operations

(RSS)

Product development(X. Wu, A. Safaeinili, J.

Sonntag)

Product development(X. Wu, A. Safaeinili, J.

Sonntag)

Product validation & modeling(K. Jezek)

Product validation & modeling(K. Jezek)Operations Management

(TBD) Operations Management

(TBD)

Product distribution (Byrd, OSU)

Product distribution (Byrd, OSU)

Aircraft management

(RSS)

Aircraft management

(RSS)

Measurement Concept• Three systems working together

– GISMO (Glaciers and Ice Sheet Mapping Observatory) radar (150-450 MHz) to map both surface and bottom of 3D topography of ice sheets

– WISE (JPL radar 1 – 20 MHz) to provide nadir depth sounding measurements of ice thickness for warmer and fractured ice

– WFF Lidar to provide accurate surface profile for elevation change detection to complement ICEsat and to provide validation for WISE and GISMO

Lidar

GISMO

WISE

Lidar antenna hook up WISE antenna

hook up

GISMO antenna hook up

GISMO antenna hook up

Basal topography sensed using multi-antenna tomographic SAR measurements at 150 MHz.New antenna and receiver systems to: Extend GISMO 20 MHz bandwidth to 100 MHz Reduce horizon gain of GISMO antenna to eliminate late time surface clutter

Airborne Topographic Mapper

parallel-pattern

transverse pattern

120MHz

120MHz

Payloads: WISE, GISMO, LIDAR

full-scale EM simulation

OSU miniature planar UWB antenna element

WISE radar (demo version)

25

”

Radar System Block Diagram

• Leverages GISMO and WISE designs

• Integrates both systems with a common controller and data system– Also provides synchronization

timing for WFF lidar system

• Full digital signal processing on both transmit and receive– Three waveform generators– Twenty digital receivers– Real-time processing for data

volume reduction

• All solid-state transmitters• Design based on JPL’s WISE radar

and Europa Sounder with negligible risk to build

GISMO transmit antenna array

WISE antennae

Receiver

Transmitter

GISMO receive antenna array

RSS Digital Receiver & Data AcquisitionRSS Team Brings … • Remote Sensing Systems Experience: Developing end to end solutions for airborne remote sensing from manned and unmanned aircraft since 1990.• Broad Experience: 20+ yrs in developing data acquisition & management, embedded systems, radar digital receiver & processing, processor and real-time operational data system solutions. • FPGA-based Digital Receivers: Developing state of the art, high performance, multi-channel airborne FPGA digital receiver solutions since 1998 for manned and unmanned platforms.•Full Demonstration & Developing Environment: Hardware and software development boards and software to mitigate risk.

Conduction Cooled 3U PCIe System

Virtex-5 Multi Channel Digital Receiver

Embedded Network Processor

Leverage RSS Receiver and Data System Technology - Multi-channel Digital Receiver: Can support BIIR requirements. - Novel System Architecture: Supports up to 16 receiver channels, 25+ Gb/s processing bus and 10 Gb/s CompactPCIe bus 3rd party support. - Embedded Network Processor: Provides multiple independent Gigabit Ethernet interfaces for real-time access to data & system and a means for efficient data distribution on ground.- Utilize AAMPS Framework: Novel network-based, remote access, real-time data acquisition, control, distribution & visualization system developed for NOAA research aircraft.

Operational Objectives

• Obtain 3-dimensional imagery of ice sheet surface and base by increasing level of complexity

– Phase 1: 10 selected glacier basins in Greenland and Antarctica– Phase 2: 100 km strip from grounding line– Post Ventures: complete coverage

• Logistical requirement– 5 hours per glacier system (500 km/hour, 10km swath)– 1300 hours to cover 100 km strip about Antarctica from the grounding line– 400 hours to cover 100 km strip about Greenland– Conservative data collection cost estimate: <$20 M for phase 1 and 2 with 100%

overhead and assuming $5K/flight hour

Thule

Sondrestrom

South Pole

Byrd

McMurdo

Dome 'C’

Dumont D'Urville

Halley Bay

selected glaciers major aircraft stations

Platform options & Operating Concept• Platform options

– Use available planes for early phase– Ken Borek Air Twin Otter

or NASA Wallops P-3 for Greenland– Twin Otter or Air National Guard C-130 for

Antarctica– Wallops encourage BIIR use of P-3– Unsolicited proposing that NSF recommission one

of their Hercules C-130 planes for later phase. – UAV possible but unlikely because of altitude and

operational complexity• Cycle GISMO, ATM, and WISE to avoid

interference from simultaneous operation• Fly over target area and collect return signals at

on-board Operations Center• Ocean flight calibration.• Validation using existing data sets and cross

flights.• Real time on-board processing, on-field processing

and post processing.

DAC January 2009

Final Product Deliverables to Science Community

Base image mosaic

Surface intensity map

3D base topography and intensity

• Ice thickness maps• Surface/base topography/intensity maps• Bed rock/water classification maps• Multilook azimuth compressed images• Basal layer roughness and correlation length maps• Internal layer images• Google earth interface to final products, flight lines and raw data sets

July 20, 2008, 17 km wide, 150 MHz radar tomography GISMO image (geocoded) of the upper surface of the ice sheet across Jacobshavn Glacier (right). 2000 Radarsat C-band image (center). Inset map from Radarsat mosaic (left). July 15, 2008, MERIS optical image (lower left). GISMO image located at about 69.3N, 48.3 W

Multi-frequency images of ice sheet surface across Jacobshavn glacier

Lake

Ice stream

Crevasse Band

17 km

24 km

7/15/08, MERIS optical image

Nov/Dec 2000, C-band Radarsat

7/20/2008, 150 MHz GISMO

Data processing scheme

GISMO raw dataGISMO raw data

GISMO processor

GISMO processor

Ice thickness dataSurface topography/intensity archive

Base topography/intensity archive

Ice thickness dataSurface topography/intensity archive

Base topography/intensity archive

Orthorectification

Image mosaic

Orthorectification

Image mosaic

Ice thickness mapsSurface/base topography/intensity maps

Bed rock/water classification maps

Ice thickness mapsSurface/base topography/intensity maps

Bed rock/water classification maps

Bed rock/water

classifier

Bed rock/water

classifier

WISE raw dataWISE raw data LIDAR raw dataLIDAR raw data

WISE processor

WISE processor

LIDAR processor

LIDAR processor

Data fusion processor

Data fusion processor

Processing time requirements can be met by commercially available, low cost (<$100K), multiprocessor architectures

Range compression

Range compression

Multi-squint sounder

processor

Multi-squint sounder

processor

CalibrationCalibration

Beam Steering surface clutter

rejection

Beam Steering surface clutter

rejection

Tomography/interferometry processor:

• Left - right separation • Topography estimation

• Amplitude estimation

Tomography/interferometry processor:

• Left - right separation • Topography estimation

• Amplitude estimation

Products and Information Flow

Raw data Archive(380 TB)

Raw data Archive(380 TB)

Final product archive: Ice thickness maps Surface topo/intensity maps Base topo/intensity maps Water/rock classification maps Multilook azimuth compressed images Basal layer roughness and correlation length maps Internal layer images Google earth interface to final products, flight lines and raw data sets

Final product archive: Ice thickness maps Surface topo/intensity maps Base topo/intensity maps Water/rock classification maps Multilook azimuth compressed images Basal layer roughness and correlation length maps Internal layer images Google earth interface to final products, flight lines and raw data sets

Intermediate products:(not archived)

Range compressed dataSingle look azimuth

compressed data

Intermediate products:(not archived)

Range compressed dataSingle look azimuth

compressed data

General public General publicScience community

Science community

• Only raw data and final products are archived.• Raw data will be available to science community

per request.• Intermediate products including range compressed

data and single look azimuth compressed data are not archived. But they will be available after reprocessing to science community per request.

(20 GB)

• Conservative estimate of storage disk cost: $500K.

• Data distribution heritage from Radarsat Antarctic Mapping Mission: http://bprc.osu.edu/rsl/radarsat/data/

Summary• The measurement is one-time shot due to the slow change of the

bedrock elevation. It will stand as a reference climatological baseline.• The technology is mature and proven. Radar system build is low risk

(commercial or existing parts) and leverages JPL heritage.• Unique ice thickness measurement directly complement DESDynI and

ICESAT observation of surface velocity and surface elevation change• Issues to be resolved during proposal phase:

– Installation of antennas (e.g. NYANG 109th airforce flight worthiness restrictions)

– Logistical capabilities around Antarctica– Instrument integration– Supplement instruments (gravimeters)

• Potential Partners– ESA has expressed possible interest in co-funding deployments as well as

providing additional radar now supporting BIOMASS related experiments– OPP/NSF C-130 logistics in Antarctica (e.g. fuel)

• Costs: Conservative estimate of costs in order of ~$30M