Velocity despiking
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Overview
Any measured signal may be contaminated by spikes. These spikes are typically short-lived and transient, which result in sudden change in the measured signal.
Spikes in velocities measured by acoustic-Doppler velocimeters can result from aliasing of the Doppler signal, in particular when pulses become contaminated by reflecting from complex objects and boundaries <ref name="GoringNikora"> {{#arraymap:D. G. Goring and V.I. Nikora|,|x|x|, |and}}. 2002. Despiking Acoustic Doppler Velocimeter Data. Journal of Hydraulic Engineering. doi:10.1061/ASCE0733-94292002128:1117 </ref>. Several techniques exist for de-spiking.
The most used with acoustic-Doppler velocimeters are the phase-space thresholding techniques <ref name="GoringNikora"\>. Other techniques currently being investigated by the subgroup are those used in atmospheric turbulence studies <ref name="Starkenburg"> {{#arraymap:D. Starkenburg, S. Metzger, G.J. Fochesatto, J.G Alfieri, R. Gens, A. Prakash and J. Cristobal|,|x|x|, |and}}. 2016. Assessment of Despiking Methods for Turbulence Data in Micrometeorology. J. Atmos. Oceanic Technoly. doi:10.1175/JTECH-D-15-0154.1 </ref>, in particular median filter despiking technique <ref name="Brock"> {{#arraymap:F.V. Brock|,|x|x|, |and}}. 1986. A nonlinear filter to remove impulse noise from meteorological data. J. Atmos. Oceanic Technoly. doi:10.1175/1520-0426(1986)003,0051:ANFTRI.2.0.CO;2 </ref>.
Notes
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