CIMMS Accomplishments in Radar Engineering

Sebastián TorresSr. Research Scientist

CIMMS/The University of Oklahomaand National Severe Storms Laboratory/NOAA

CIMMS 40th Anniversary CelebrationNovember 15th, 2018 - Norman, OK

Aren’t engineers cool?• “Engineering is the creative application of science,

mathematical methods, and empirical evidence to the innovation, design, construction, operation and maintenance of structures, machines, materials, devices, systems, processes, and organizations for the benefit of humankind.”

-Wikipedia

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Weather Radar Engineering• Radar Engineering R&D areas– Software

• Software infrastructure• Signal processing techniques

– Hardware• Radar systems• Radar technologies

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Some numbers• Doppler Weather Radar R&D theme added in 1996– Evidence of radar R&D predates 1996– Recast as Weather Radar R&D in 2011

• CIMMS employees make up 70% of NSSL’s Radar Division

– 14 out of 18 engineers in RRDD are CIMMS employees

– The Advanced Radar Techniquesteam is 100% CIMMS engineers

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CIMMS first (?) contribution

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Cimarron research radar

WSR-88D Open Systems

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• Interoperability• Portability• Open standards

WSR-88D Open Systems

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ORPG(1996)

ORDA(1996)

OPUP (1997)

Signal Processing Techniques

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Radar signals

Radar variables

• Radar signals are messy!• Users need clean radar data

Weather Radar Signal

Processing

Geeky signalprocessing superhero

Signal Processing Examples

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Getting Better Velocity Data Filtering Echoes from the Ground

Conventional ModeStaggered PRT Mode

Refle

ctivi

tyDi

ffere

ntia

lRef

lect

ivity

Velo

city

Corre

latio

n Co

effic

ient

No Filtering

Velo

city

Filtering with WET and CLEAN-AP

Research to Operations

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Systematic Phase Coding (SZ-2) 2007Super Resolution 2008Coherency-Based Thresholding (CBT) 2014Radial-by-Radial Noise Estimator 2014Staggered PRTCLEAN-AP Ground Clutter FilterWeather Environment Thresholding (WET)Range OversamplingHybrid-Scan Estimator (HSE)Improved DP Variable EstimatorsWind Turbine Clutter MitigationPolarimetric Spectral DensitiesInterference Filters

WSR-88D

Sign

al P

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ssin

g Te

chni

ques

OperationsTransitionResearch

CIMMS has a rich history of contributions related to the design, implementation, calibration, and enhancement of weather radar systems

Radar Systems

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KOUN(1996)

NOXP(2007)

NWRT(2003) TPD

(2015)

Phased Array Radar at NSSL

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The National Weather Radar TestbedNorman, OK

Reflectivity at 0.5º – 20 May 2013 Moore, OK tornado

4.2-min updates1.2-min updatescourtesy of P. Heinselman (NSSL)

ConventionalPAR

Rapi

d Up

date

s

clear airslow updates

Reflectivity at 0.5º

Adap

tive

Scan

ning

Reflectivity at 0.5ºplus aircraft tracks

Mul

tifun

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n

From 2003 through 2016 the legacy NWRT PAR

supported demonstrations of unique capabilities

An upgrade for the NWRTAdvanced signal processing

Adaptive weather observationsMultifunction

Outdated technologyPassive array

Single polarization

Modern technologyActive array

Dual polarization

The Advanced Technology Demonstrator has been developed over the last 5 years with funding from NOAA and the FAA (~$38M). CIMMS collaborates with government, industry, and other university organizations.

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Consecutive scans of SimulatedRadar Data

Command and Control Simulator

SPARC Simulator *

I/Q Data

DSP

Adaptive Scanning

Scan

Consecutive scans of OriginalRadar Data

Adaptive Scan

Temporal interpolation

RUN THE COMMAND AND CONTROL LOOP

Radar System Simulations2 SELECT THE CASE

ConvectiveData from the WSR-88D in

Omaha, NE on 05/07/2015 (02:02:27Z)

Z vr

ZDR ρhv

StratiformData from the WSR-88D in

Grand Rapids, MI on 12/13/2017

(22:48:53Z)

Z vr

ZDR ρhv

NCEI Archived DataDual-Polarization

Wide variety of casesData processed with

advanced DSP techniquesPublicly available

1 DEFINE THE RADAR ARCHITECTURE AND INITIAL SCANNING

CONFIGURATION

Reflector Planar PAR

Cylindrical PAR 4-faced PAR

-50 -40 -30 -20 -10 0 10 20 30 40 50-160

-140

-120

-100

-80

-60

-40

-20

0

Co-polar at = 0°

Cross-polar at = 0°

Antenna Patterns

Waveforms

Time ( s)0 10 20 30 40 50 60 70 80

Nor

mal

ized

Mag

nitu

de

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1Waveform: NLFM Pulse + CW Fill Pulse

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

-0.2

-0.1

0

0.1

0.2

Spatial Sampling

Temporal SamplingDwell type

M, PRTsP2P phase coding

Dual Polarization Transmission

Single polarization (H or V)Simultaneous (SHV)Alternate (AHV)

The next revolution is coming!

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The next 40 years• Operational use of phased array radars

– Address technology obsolescence – Improve weather surveillance

• Filling observation gaps– Retrieve meteorological information from

radar data to improve warnings and forecasts– Use hybrid observing-system networks

to improve quality, availability, and coverage

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The perfect partnership to save lives and property