Brian scannell at 13:57, 10 January 2023

2023-01-10T13:57:30Z

← Older revision		Revision as of 13:57, 10 January 2023
Line 30:		Line 30:
	\| segment_outlier		\| segment_outlier
	\| Flag data points <math> > 3 \sigma</math> away from segment mean for bin.		\| Flag data points <math> > 3 \sigma</math> away from segment mean for bin.
	\| 3 \sigma</math>		\| <math>3 \sigma</math>
	\| 1		\| 1
	\| 2		\| 2
Line 38:		Line 38:
	\| profile_outlier		\| profile_outlier
	\| Flag data points <math> > 3 \sigma</math> away from beam-profile-mean.		\| Flag data points <math> > 3 \sigma</math> away from beam-profile-mean.
	\| 3 \sigma</math>		\| <math>3 \sigma</math>
	\| 0		\| 0
	\| 0		\| 0

Yuengdjern at 15:53, 11 July 2022

2022-07-11T15:53:55Z

← Older revision		Revision as of 15:53, 11 July 2022
Line 149:		Line 149:
	\| Bit 5		\| Bit 5
	\| dll_intercept_too_high		\| dll_intercept_too_high
	\| Flag values where intercept > threshold (threshhold <math> = 2yint\~~_expected~~ = 2(2*sigma_v^2) </math>, where <math> \sigma_v </math> is expected accuracy in along-beam vel.		\| Flag values where intercept > threshold (threshhold <math> = 2yint\_{expected} = 2(2*\sigma_v^2) </math>, where <math> \sigma_v </math> is expected accuracy in along-beam vel.
	\| Instrument dependent		\| Instrument dependent
	\| 0		\| 0

Yuengdjern at 21:39, 3 June 2022

2022-06-03T21:39:20Z

← Older revision		Revision as of 21:39, 3 June 2022
Line 156:		Line 156:
	\| 64		\| 64
	\| Bit 6		\| Bit 6
	\| ~~insufficient_dll_samples_for_regression~~		\| regression_poorly_conditioned
	\| Flag values where there are fewer than a certain number of points for the regression		\| Flag values where there are fewer than a certain number of points for the regression
	\| 3		\| 3

Yuengdjern: Created page with " '''How ADCP structure function quality-control flags are applied''' The Q (quality control) flags associated with shear-probe measurements are not compatible with the Ocean..."

2022-06-03T21:37:55Z

Created page with " '''How ADCP structure function quality-control flags are applied''' The Q (quality control) flags associated with shear-probe measurements are not compatible with the Ocean..."

New page

'''How ADCP structure function quality-control flags are applied'''

The Q (quality control) flags associated with shear-probe measurements are not compatible with the Ocean Sites [http://www.oceansites.org/ Ocean Sites] for quality control (QC) coding.

Every dissipation estimate from every probe must have Q flag.
The numerical values of the Q flags are as follows:

'''Level 2:'''
{| class="wikitable"
|-
! Flag Mask
! Bit
| Flag attribute
| Flag meaning
! Threshold value
| Ex: True =1 / False =0
| Ex: Q value
|-
| 1
| Bit 0
| Manually defined by user
| Manually defined by user
| Manually defined by user
| 0
| 0
|-
| 2
| Bit 1
| segment_outlier
| Flag data points <math> > 3 \sigma</math> away from segment mean for bin.
| 3 \sigma</math>
| 1
| 2
|-
| 4
| Bit 2
| profile_outlier
| Flag data points <math> > 3 \sigma</math> away from beam-profile-mean.
| 3 \sigma</math>
| 0
| 0
|-
|
|
|
|
|
|
| Final Q = 2
|}

'''Level 3:'''
{| class="wikitable"
|-
! Flag Mask
! Bit
| Flag attribute
| Flag meaning
! Threshold value
| Ex: True =1 / False =0
| Ex: Q value
|-
| 1
| Bit 0
| Manually defined by user
| Manually defined by user
| Manually defined by user
| 0
| 0
|-
| 2
| Bit 1
| insufficient_number_velocity_samples
| Flag segments where the ratio of the number of viable values in the velocity difference to the total number of data points is less than the threshold
| 0.5
| 0
| 0
|-
| 4
| Bit 2
| too_close_to_range_limits
| Flag bins that are too close to the first or last range bin (I.e. not enough bins to do differencing)
| 3
| 1
| 4
|-
|
|
|
|
|
|
| Final Q = 4
|}

'''Level 4:'''
{| class="wikitable"
|-
! Flag Mask
! Bit
| Flag attribute
| Flag meaning
! Threshold value
| Ex: True =1 / False =0
| Ex: Q value
|-
| 1
| Bit 0
| Manually defined by user
| Manually defined by user
| Manually defined by user
| 0
| 0
|-
| 2
| Bit 1
| Rsquared_too_low
| Flag values where <math> R^2 < </math> threshold
| 0.6
| 0
| 0
|-
| 4
| Bit 2
| delta_epsi_too_large
| Flag values where <math> \delta \epsilon / \epsilon > </math> threshold
| 0.6
| 1
| 4
|-
| 8
| Bit 3
| A3_coeff_invalid
| Flag values where <math> a_3 </math> < threshold
| 0
| 0
| 0
|-
| 16
| Bit 4
| dll_intercept_too_low
| Flag values where intercept (<math> a_0 </math>) < threshold
| 0
| 1
| 16
|-
| 32
| Bit 5
| dll_intercept_too_high
| Flag values where intercept > threshold (threshhold <math> = 2*yint\_expected = 2*(2*sigma_v^2) </math>, where <math> \sigma_v </math> is expected accuracy in along-beam vel.
| Instrument dependent
| 0
| 0
|-
| 64
| Bit 6
| insufficient_dll_samples_for_regression
| Flag values where there are fewer than a certain number of points for the regression
| 3
| 0
| 0
|-
| 128
| Bit 7
| dll_slope_out_of_range
| Flag values where slope <math> a_1 < 0 </math> as this would lead to negative epsilon.
| 0
| 0
| 0
|-
|
|
|
|
|
|
| Final Q = 20
|}

<br />

The Q flags are combined by their addition.
For example a Q value of 20 means that the dissipation estimated failed both dissipation ratio limit test and the resolved variance test.
A value of 255 means that all tests failed.
The reasons for a failure can be decoded by breaking the value of Q down to its powers of 2.
Note that importance (severity of the failure) is ranked by the numeric value of the flag mask.

Velocity Profiler data flags - Revision history

Brian scannell at 13:57, 10 January 2023

Yuengdjern at 15:53, 11 July 2022

Yuengdjern at 21:39, 3 June 2022

Yuengdjern: Created page with " '''How ADCP structure function quality-control flags are applied''' The Q (quality control) flags associated with shear-probe measurements are not compatible with the Ocean..."