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Profiling the ABL using a Profiling the ABL using a Small Unmanned Meteorological Small Unmanned Meteorological

Observer (SUMO)Observer (SUMO)

- Wind measurements -- Wind measurements -

Stephanie Mayer

PhD – Seminar

October 23, 2007

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Stephanie Mayer, GFI

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Why remote-controlled aircrafts?Why remote-controlled aircrafts?

• repeated, fine-time-scale soundings to investigate meteorological parameters of the ABL

• economical, controllable and recoverable platform to carry meteorological sensors and instrumentation for in situ measurements of atmospheric parameters (Konrad, 1970)

• ability to capture a 3-D image of the state of the ABL• extremely flexible

• limitations: fog/clouds, precipitation, storms

Stephanie Mayer, GFI

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Wind triangle Wind triangle

Stephanie Mayer, GFI

wind vector:wind speed

wind direction

heading vector:true air speed (TAS)azimuth angle (Ψ)

course vector:

ground speed (GS)

flight-path azimuth (X)

heading + wind = course

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Coordinate systems (1)Coordinate systems (1)

Stephanie Mayer, GFI

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Coordinate systems (2)Coordinate systems (2)

Stephanie Mayer, GFI

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Coordinate systems (3)Coordinate systems (3)

Stephanie Mayer, GFI

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Required variablesRequired variables

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namename abbreviationabbreviation devicedevice

ground speed GSTrimble GPS

flight-path azimuth Χ

true air speed TAS MiniAir

angle of sideslip β wind vane

azimuth angle (yaw) Ψ

inclination angle (pitch) θ Microstrain

bank angle (roll) φ

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Transformation of heading (1)Transformation of heading (1)

Stephanie Mayer, GFI

aerodynamic

body

geodetic

Mba(α,β)

Mgb(ψ,θ,φ)

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Transformation of heading (2)Transformation of heading (2)

1sinsincossin

0cossin

sinsincoscoscos

βαβα

ββ

αβαβα

baM

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ΘΦΘΦΘΨΦ

ΨΘΦ

ΨΦ

ΨΘΦΨΘ

ΨΦ

ΨΘΦ

ΨΦ

ΨΘΦΨΘ

coscoscossinsinsinsin

cossincos

sincos

cossinsincoscos

cossin

sinsincos

coscos

sinsinsinsincos

gbM

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Test with a motor-gliderTest with a motor-glider

Stephanie Mayer, GFI

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Windprofile Windprofile

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SUMO – wind estimationSUMO – wind estimation

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SUMO – some technical detailsSUMO – some technical details

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specificationsspecifications

wing span 80 cm

length 75 cm

weight 600 g

performanceperformance

horizontal (air) speed 12-18 m/s 35 m/s

climb rate 7-10 m/s 15 m/s

altitude range above ground ~ 3.5 km

horizontal range / endurance ~4 km / ~0.5 h

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Wind estimation by flying in circlesWind estimation by flying in circles

Stephanie Mayer, GFI

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Wind estimation by flying in circlesWind estimation by flying in circles

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down

GS [m/s]

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Windprofile – circling methodWindprofile – circling method

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Near futureNear future

Stephanie Mayer, GFI

• comparison of both methods

Twinstar II

Funjet

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SummarySummary

Stephanie Mayer, GFI

• two methods of retrieving airborne wind profiles have been shown

• 1. method: free flight pattern

but many components have to be used• 2. method: less equipment

but limited to circling pattern• both methods are quite promising

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OutlookOutlook

Stephanie Mayer, GFI

• comparison of both methods on two small aircrafts (Funjet, Twin Star II)

• comparison of measurements and model (WRF) data