LAP®-3000 Wind profilerOptimizing the wind measurementJuhani PolvinenRaisa Lehtinen
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Agenda
LAP®-3000 Wind profilerWind profiler measurement set-upQuality control of wind profiler dataQuality control of meteorological information
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LAP®-3000 Wind profiler
Radio frequency remote sensing instrumentProvides
wind profile turbulence profile virtual temperature profile (with RASS)
TypicalAveraging period ~10 minutesSampling every 30 m Vertical resolution 60 m
Volumetric measurementDirectly above the site
Doppler beam swinging (DBS)3-5 beams
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LAP®-3000 Components
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LAP®-3000 Antenna System
The antenna system consists of four or nine planar panels with a clutter reduction screenAntenna panels oriented horizontally
Beams point to four orthogonal oblique directions and to zenith
Micro-patch antenna elementsElectrically switched phase delays change the pointing direction
Each planar panel protected by integral radome
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LAP-XM application softwareAcquires and processes signal data Computes, displays and saves meteorological data productsConverts data products to new formatsMonitors data product qualityControls operation of the profiler from remote locationsGenerates wind and temperature outputs
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How to ensure information availability?Supporting elements
Decision Support Information Decision Support Services
Data Assurance Data quality, accessibility, availability
Performance Remote Monitoring
Response TimeService contract:24/7 HelpDesk,
Express Delivery, On-site Repair
Support Technical Support, Repair, Spares,
Training…
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How to ensure information availability?Vaisala SiteConnect
Remote monitoring
Database Server
Internet
Application server
ADSL - GPRS - ISDN -PSTN
Remote monitoring
Web Server
Firewall
Diagnosis and RepairPatch ManagementRemote AccessPreventive MaintenanceUsage MonitoringReporting
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Wind profiler measurement optimization
Wind profilers offer a range of alternative measurement configurationsUser's application requirements
time resolution and update interval of wind observations vertical resolutionthe altitude range of interestlowest measurement altitude
Optimal profiler set-up often requires adjustments and test iterations
specific requirements of the user's applicationlocal radio interference and clutter environmentclimate and seasonal effects
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Wind profiler measurement optimization
The optimal choice is a balance betweenfrequent observations of the lower boundary layer, or alternating lower and upper boundary layer winds?maximize detection sensitivity or height resolution? maximize shear detection or outlier rejection?short averaging time, or more stable and higher reliability estimates?
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LAP®-3000Installation at Barajas Airport
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Operational parameters for Barajas airport LAP-3000
Parameters were adjusted in 3-4 iterations during a 1 month evaluation period
Quality control using 30 min of history dataWinds are averaged for 10 minutesRASS virtual temperature is averaged for 3 minute every 30 min The lower boundary layer is observed 50% of time with 60m height resolutionThe full boundary layer (<3.2km) is observed 50% of time in 100mheight intervals and 200m height resolution
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Wind profiler signal processing stepsTime series
Spectra
Moments
Met. products
Time-frequency filtering
•Multiple peak picking•Feature identification
Quality control
Time/height continuity analysis
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Advanced methods for interference removal
Intermittent clutter filteringintermittent clutter sources: birds, airplanesanalyze raw radar time series data using a time-frequency presentation (Gabor frame expansion)intermittent clutter signals are separated and removed using a statistical thresholdimplemented in cooperation with DWD (Gerhard Teschke and Volker Lehmann)
Power spectrum analysisMultiple peak pickingRadio frequency interference rejection
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Time-velocity analysis of raw radar signal to remove interference sources
Time
Vel
ocity
1) Radar power intensity from one measurement height (Velocity versus Time)
2) Statistical filter removes intermittent features
Bird echoes Atmospheric echo
Volker Lehmann / DWD
Time-frequency
filtering
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Multiple peak picking method finds the wind velocity from other echoes
standard MPP
Multiple peakpicking
Featureidentification
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Quality control of meteorological information
Wind fieldTime-height continuity analysis and radar beam consistency checkflag suspect results in severe RFI environment
Wind shearFeature enhancement through noise reduction
Other phenomena
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• Time-height continuity analysis and radar beam consistency check flag suspect results in severe RFI environment
Post-processing of wind results
Time/heightcontinuityanalysis
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Time/heightcontinuityanalysis
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Application specific end product: wind field and vertical windshear above airport runway
Featureenhancement
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Wind field and vertical windshear above airport runway: filtered data for feature extraction
Featureenhancement
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Thank [email protected]@Vaisala.com
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