De-spiking parameters - Revision history

Marcus at 19:26, 7 June 2024

2024-06-07T19:26:14Z

← Older revision		Revision as of 19:26, 7 June 2024
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	It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.		It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.
	You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.		You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.

	~~<! –– * [thresh] Threshold value for the ratio of the instantaneous rectified signal to its smoothed version. A value of 8 is a good starting point for a VMP. ––>~~
	<! –– * [smooth] The cut-off frequency of the first-order Butterworth filter that is used to smooth the rectified input signal. The time scale of smoothing is approximately 1/(2*smooth). A value of 0.5 is a good starting point for a VMP. ––>
	~~<! –– * [Fs] Sampling rate (Hz). ––>~~
	<! –– * [N] Spike removal scale. A total of 1.5N data points are removed. N/2 points are removed before a spike, and N points are removed after a spike. The replaced data is an average of the adjacent neighbouthood. Averaging uses ~Fs/(4smooth) points from each side of a spike. ––>

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Marcus at 20:09, 6 June 2024

2024-06-06T20:09:45Z

← Older revision		Revision as of 20:09, 6 June 2024
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	You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.		You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.

			<! –– * [thresh] Threshold value for the ratio of the instantaneous rectified signal to its smoothed version. A value of 8 is a good starting point for a VMP. ––>
			<! –– * [smooth] The cut-off frequency of the first-order Butterworth filter that is used to smooth the rectified input signal. The time scale of smoothing is approximately 1/(2*smooth). A value of 0.5 is a good starting point for a VMP. ––>
			<! –– * [Fs] Sampling rate (Hz). ––>
			<! –– * [N] Spike removal scale. A total of 1.5N data points are removed. N/2 points are removed before a spike, and N points are removed after a spike. The replaced data is an average of the adjacent neighbouthood. Averaging uses ~Fs/(4smooth) points from each side of a spike. ––>

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CynthiaBluteau: Categorization

2021-11-23T15:32:09Z

Categorization

← Older revision		Revision as of 15:32, 23 November 2021
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	return to [[Flow chart for shear probes]]		return to [[Flow chart for shear probes]]

			[[Category:Shear probes]]

Rolf at 20:20, 19 November 2021

2021-11-19T20:20:27Z

← Older revision		Revision as of 20:20, 19 November 2021
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	If more than a few percent of the data used for a particular estimate of <math>\varepsilon</math> have been modified by the de-spiking algorithm than such estimates are suspect.		If more than a few percent of the data used for a particular estimate of <math>\varepsilon</math> have been modified by the de-spiking algorithm than such estimates are suspect.

	A widely used [[De-spike the shear-probe data]] identifies shear-probe signal anomalies by comparing the absolute shear against a smoothed version of the absolute shear.		A widely used algorithm, [[De-spike the shear-probe data]], identifies shear-probe signal anomalies by comparing the absolute shear against a smoothed version of the absolute shear.
	It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.		It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.
	You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.		You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.

Rolf at 20:16, 19 November 2021

2021-11-19T20:16:55Z

← Older revision		Revision as of 20:16, 19 November 2021
Line 2:		Line 2:
	If more than a few percent of the data used for a particular estimate of <math>\varepsilon</math> have been modified by the de-spiking algorithm than such estimates are suspect.		If more than a few percent of the data used for a particular estimate of <math>\varepsilon</math> have been modified by the de-spiking algorithm than such estimates are suspect.

	A widely used [[de-~~spiking algorithm~~]] identifies shear-probe signal anomalies by comparing the absolute shear against a smoothed version of the absolute shear.		A widely used [[De-spike the shear-probe data]] identifies shear-probe signal anomalies by comparing the absolute shear against a smoothed version of the absolute shear.
	It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.		It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.
	You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.		You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.

Rolf at 21:55, 18 November 2021

2021-11-18T21:55:11Z

← Older revision		Revision as of 21:55, 18 November 2021
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	The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. These collisions cause a very large and transient signal from the shear probe. These anomalies typically last for ~50ms, but can be longer in the case of jellyfish. They do not represent shear and bias high the variance of shear and the rate of dissipation. These anomalies should be replaced with data of constant value and the data so modified must be tracked because it is a quality control metric.		The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. These collisions cause a very large and transient signal from the shear probe. These anomalies typically last for ~50ms, but can be longer in the case of jellyfish. They do not represent shear and bias high the variance of shear and the rate of dissipation. These anomalies should be replaced with data of constant value and the data so modified must be tracked because it is a quality control metric.
			If more than a few percent of the data used for a particular estimate of <math>\varepsilon</math> have been modified by the de-spiking algorithm than such estimates are suspect.

	A widely used [[de-spiking algorithm]] identifies shear-probe signal anomalies by comparing the absolute shear against a smoothed version of the absolute shear.		A widely used [[de-spiking algorithm]] identifies shear-probe signal anomalies by comparing the absolute shear against a smoothed version of the absolute shear.
	It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.		It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.
			You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified.

	~~You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified because this is a quality-control parameter.~~
	~~If more than a few percent of the data used for a particular estimate of <math>\varepsilon</math> have been modified by the de-spiking algorithm than such estimates are suspect.~~

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	return to [[Flow chart for shear probes]]		return to [[Flow chart for shear probes]]

Rolf at 21:53, 18 November 2021

2021-11-18T21:53:12Z

← Older revision		Revision as of 21:53, 18 November 2021
Line 1:		Line 1:
	The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. These collisions cause a very large and transient signal from the shear probe. These anomalies typically last for ~50ms, but can be longer in the case of jellyfish. They do not represent shear and bias high the variance of shear and the rate of dissipation. These anomalies should be replaced with data of constant value and the data so modified must be tracked because it is a quality control metric.		The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. These collisions cause a very large and transient signal from the shear probe. These anomalies typically last for ~50ms, but can be longer in the case of jellyfish. They do not represent shear and bias high the variance of shear and the rate of dissipation. These anomalies should be replaced with data of constant value and the data so modified must be tracked because it is a quality control metric.

			A widely used [[de-spiking algorithm]] identifies shear-probe signal anomalies by comparing the absolute shear against a smoothed version of the absolute shear.
			It requires a threshold and smoothing parameter and the number of points to be replaced around a spike.

			You may use other de-spiking algorithms but it important to keep track of the fraction of the data that has been modified because this is a quality-control parameter.
			If more than a few percent of the data used for a particular estimate of <math>\varepsilon</math> have been modified by the de-spiking algorithm than such estimates are suspect.

	----------------------------		----------------------------
	return to [[Flow chart for shear probes]]		return to [[Flow chart for shear probes]]

Ilker at 15:39, 9 November 2021

2021-11-09T15:39:26Z

← Older revision		Revision as of 15:39, 9 November 2021
Line 1:		Line 1:
	The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. These collisions cause a very large and transient signal from the shear probe. These anomalies typically last for ~50ms, but can be longer in the case of jellyfish. They do not represent shear and bias high the variance of shear and the rate of dissipation. These anomalies should be replaced with data of constant value and the data so modified must be tracked because it is a quality control ~~matric~~.		The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. These collisions cause a very large and transient signal from the shear probe. These anomalies typically last for ~50ms, but can be longer in the case of jellyfish. They do not represent shear and bias high the variance of shear and the rate of dissipation. These anomalies should be replaced with data of constant value and the data so modified must be tracked because it is a quality control metric.

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			return to [[Flow chart for shear probes]]

Aleboyer: Created page with "The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. Thes..."

2021-08-20T22:51:54Z

Created page with "The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. Thes..."

New page

The shear probe will collide with plankton and other particulates in the water, and it will occasionally hit jellyfish and even some fish that do not get out of its path. These collisions cause a very large and transient signal from the shear probe. These anomalies typically last for ~50ms, but can be longer in the case of jellyfish. They do not represent shear and bias high the variance of shear and the rate of dissipation. These anomalies should be replaced with data of constant value and the data so modified must be tracked because it is a quality control matric.