Transcript Evaluation of the TAMDAR Turbulence Algorithm Larry Cornman

Evaluation of the
TAMDAR
Turbulence Algorithm
Larry Cornman
Research Applications Laboratory
National Center for Atmospheric Research
Turbulence Calculations
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The TAMDAR turbulence algorithm is
based on:
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True airspeed (TAS) values.
Sampled at 10.67Hz.
Anti-aliasing filter applied.
32-point window = 3 second interval.
Maximum likelihood algorithm.
Evaluation Methodology
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Use NCAR algorithm (max. likelihood
technique) applied to the TAMDAR TAS
data:
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Use 32-point window.
Account for anti-aliasing filter.
Look into other window lengths.
Evaluation Methodology, cont’d.
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Use NCAR algorithm applied to:
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UND high-rate TAS (nose and wing ports).
UND high-rate longitudinal wind.
UND high-rate vertical wind.
Simulated data.
Data Analysis – First Test Flight
True Airspeed from UND and TAMDAR
Data Analysis – First Test Flight
One-Lag Plot: True Airspeed from TAMDAR
Data Analysis – First Test Flight
Average Spectra: True Airspeed from TAMDAR
(109 256-pt windows, ½ overlap)
Data Analysis – First Test Flight
Raw 32-pt Spectra: True Airspeed from TAMDAR
Data Analysis – First Test Flight
EDR’s from UND and TAMDAR
Data Analysis – First Test Flight
Histogram of EDR’s from UND and TAMDAR