Multi-function Phased Array RadarFindings of the Joint Action Group

Dr. Mark Weadon

Executive Secretary

MPAR Work Group

Overview

• Motivation• What is Phased Array Radar?• Advantages of PAR in Weather Surveillance• Multi-function Capability• PAR Affordability• Research Phase Objectives• Summary and Vision• Where Do We Go From Here?

Motivation for MPAR Research

• NEXRAD and FAA’s Terminal Doppler Weather Radar are aging systems. By 2020 both will be 30+ years old. No replacement technology has been identified.

• Potential of PAR for weather surveillance well documented: National Research Council, Weather Radar Technology: Beyond NEXRAD (2003)

Aerospace Corp, Future Weather Doppler Radar Feasibility Study (2003) Strategic Plan for U.S. Integrated Earth Observation System (2005)

Motivation for MPAR Research

• In 2004 the Interdepartmental Committee for Meteorological Services and Supporting Research (ICMSSR) tasked a Joint Action Group (JAG) to assess multi-agency radar needs and to develop an Phased Array Radar Research and Development Plan.

• Originally tasked to assess PAR solely as a weather surveillance capability, the JAG expanded its scope to include aircraft surveillance under the heading of a Multi-function Phased Array Radar (MPAR) needs assessment.

What is Phased Array Radar?

Mechanically Steered, Rotating Reflector Array

Electrically Steered, Fixed Phased Array

Planar phase front

Planar phase front

Electrical added phase delay

Wavefront(Plane of equal phase radiation)

Beam is steered by progressively shifting the phases of thesignals radiated by the individual radiators.

National Weather Radar Testbed

National Radar Testbed Milestones

• National Severe Storms Lab (NSSL) accepts Spy-1 PAR from Navy (Oct. 2003)

• NSSL assigned to keep PAR “in good working order” as per NOAA/FAA/Navy MOU (Oct. 2003)

• Test and evaluation period underway (Oct. 2003 – present)• NOAA funding for PAR ($1M) in place (Feb. 2004)• Substantial progress made with FAA funding (2004)• Spy-1 PAR begins to collect data; intercomparison studies performed

with NEXRAD (May 2004 on)• National Radar Testbed becomes a national center Dec 2006

OFCM PAR Joint Action Group• Significant FindingsSignificant Findings

– MPAR has potential to far exceed present radar capabilities and meet emerging requirements

– MPAR offers improvement in spatial resolution, volume coverage, refresh rate, system reliability

– MPAR offers prospect of a significant increase in tornado lead-times– PAR based on mature technology; low technical risk– Opportunity for system convergence: 526 NEXRAD and FAA radars

in CONUS; same coverage could potentially be obtained from <335 MPARs

– Lifecycle cost savings nearly $5B anticipated from radar convergence: $2B in acquisition and $3B in lifecycle sustainment

– Seven- to ten-year intensive R&D effort required; estimated cost $200M

MIT Lincoln LaboratoryJAG-6

Mew 3/28/2005

Current Weather Radar Networks

MIT Lincoln LaboratoryJAG-5

Mew 3/28/2005

Current En Route Surveillance RadarNetworks

MIT Lincoln LaboratoryJAG-4

Mew 3/28/2005

Current Terminal Surveillance RadarNetworks

Multi-function Phased Array RadarA STRONG CASE FOR CONSOLIDATION of National Radar Assets

One Radar TYPE Scalable Design O&S Savings

Multi-Mission Weather Aircraft Ņ3DÓ Surveillance Cooperative and Non-Cooperative Aircraft

Multi-Agency NWS, FAA, DHS, DOD, DOE, DOI, FEMA, and FHWA

Legacy 526 MPAR 311

Diff. 41% -215

Terminal Area Radars 2302 Types

Weather Radars 199 2 Types

Long Range Radars 97 3 Types

AFFORDABILITY R&D GOAL MPAR $/Unit = Legacy $/Unit

FAAARSR

TDWR

NWSNEXRAD

FAAASR

PotentialSavings

Legacy Radars

Meteorological BenefitsPhased Array Radar (PAR)

• More accurate, higher resolution data in space and time; earlier detection of tornado precursors• Less than 60 second complete volume scan rates possible vs. 4-5

minutes for NEXRAD• Dwell capability (aka “staring”) – intensive sampling in areas of

interest throughout the volume• Adaptive scan strategies – ability to “tune” radar to weather at

hand• Direct measurement of cross-beam winds; 3-D vector winds as

storm-scale model input• Terrain following allows better characterization of critical boundary

layer, less clutter• Graceful degradation – lower failure rate

NEXRAD-PAR Reflectivity Comparison

NWRT Volume Scan in less than 1 min. KTLX Volume Scan took 4.2 mins.

2nd Trip

NWRTPhased Array Radar

KTLXWSR-88D

Composite Reflectivity: SPY-1 v. WSR-88DHurricane Fran Remnants

SPY-1 NEXRAD

Note heavy rain areas

several second volume scan

5 minute volume scan

New Weather Warning Paradigm

• Present – use NEXRAD radar to identify precursor signatures of tornadic storms, then extrapolate into the future. (Warn on DETECTION)

• Future – use high-resolution PAR radar data to initialize cloud-resolving ensemble forecast models to identify precursors 30-45 minutes in advance. (Warn on FORECAST )

Future Tornado Warning

Issues at time t=0 min.

Multi-functional Adaptive Scanning

Logistics Benefits of PAR• NO MOVING PARTS (4-faced array

antenna)• Scalability with Common Building

Blocks• Family of scalable radars

- Economies of scale - Common Logistics/Maintenance - Common Technology Refresh

• Improved Radar Performance - Increased Power - Increased Sensitivity - Operational Flexibility

• Improved System Reliability

• NO MOVING PARTS (4-faced array antenna)

• Scalability with Common Building Blocks

• Family of scalable radars - Economies of scale - Common Logistics/Maintenance - Common Technology Refresh

• Improved Radar Performance - Increased Power - Increased Sensitivity - Operational Flexibility

• Improved System Reliability

•Thousands of Transmit/ Receive Modules per antenna face

•Scalable antenna size

•Thousands of Transmit/ Receive Modules per antenna face

•Scalable antenna size

Solid-State Phased Array Radar Provides Significant Acquisition and Operational Benefits

Transmit/Receive (T/R) Module Cost Trends

0

0.5

1

1.5

2

2.5

3

1995 1997 1999 2005 2010

EstimatedProductionCost ($K)

Prices for Solid-State T/R Modules are Trending DownwardPrices for Solid-State T/R Modules are Trending Downward

$

Research PhaseObjectives

• Demonstrate PAR technology can be applied to the tornado detection, forecast, and warning mission in a multi-use environment.

• Demonstrate affordability of prototype multi-function PAR• Establish metrics to assess progress of R&D strategy• Determine viable economic strategy that would permit a national PAR

network to support NOAA, FAA, DOD, Homeland Security, and other national missions.

Summary and Vision

• Cost of PAR components will decline significantly over next 5 to 10 years

• Hypothesis: Multi-purpose PAR is feasible. System can simultaneously perform following functions:– Weather surveillance– Radar data assimilation into very high-resolution, very short- term,

storm-scale forecast models– Aircraft tracking, both cooperative and non-cooperative– 3-D measurements for dispersion winds– Chem/bio detection

• Polarization diversity, multi-frequency, active PAR T/R elements already exist; technical risk is low

• Must settle on best mechanism for government agencies to collaborate on a multi-purpose project of this magnitude

Where Do We Go From Here?– Establish MPAR risk reduction R&D on sound programmatic basis– Further refine agency radar mission requirements to provide

operating threshold parameters for the MPAR prototype; thresholds must be specific and tied to missions

– Build a compelling, rigorously fact-based business case for replacing legacy radars with MPAR

– Align agency equities with investment commitment to MPAR risk reduction efforts and business case development

– Research must answer following questions: -- Is MPAR feasible? i.e. does the technology meet requirements? -- Is it affordable? i.e. even if technology works, is it more cost

effective in the long run to maintain legacy radars, or to replace them with an MPAR system?

QUESTIONS?

BACKUP SLIDES

MPAR vs. Legacy Radar SystemsFor EQUAL Surveillance Coverage (MIT-LL)

Red – Legacy Coverage BetterGreen – MFS Coverage BetterGrey – Coverage Equivalent

Legacy Radars*

ARSR 9

ASR-9 24

ASR-11 9

TDWR 8

NEXRAD 14

Total 64

MPAR*

MPAR (Full) 14

MPAR (Small) 25

Total 39

North Eastern Corridor

25 Fewer

Radars

More Weather and Air Coverage to 1000 ft (AGL)

*7 Different Types

*Only 1 Type

02468

101214161820

FY03FY04

FY05FY06

FY07FY08

FY09FY10

FY11FY12

FY13

$ M

R&D hardware

Research Cost EstimateDual-pol Pre-prototype

PAR and modeling R&D

NOAA Research PhaseActions

• Acquire SPY-1A based Phased Array Radar (PAR) (October 2003), $25M, Complete

• Engineering testing and evaluation (2003-2004), $1M, Complete• Data Comparison, initial research (2004-2005), $2M, In progress• Improved Scanning Strategies, Faster Scans (Beam Multiplexing), Initial

Engineering to add Dual Polarization (2005-2006), $4M, In progress• Add dual-polarization sub-array to PAR, (2007-2009), $28M, TBD• Test and Evaluate dual-polarized phased array capabilities, (2010),

$6M, TBD• Research & Development towards operational applications to include

assimilation of PAR data into numerical models and Short Range Ensemble Forecasts (SREF), (2011-2012), $12M, TBD