adcp waves raw data processing greg dusek harvey seim, sara haines, chris calloway dept of marine...

ADCP Waves Raw Data ADCP Waves Raw Data ProcessingProcessing

Greg DusekGreg Dusek Harvey Seim, Sara Haines, Chris Harvey Seim, Sara Haines, Chris

CallowayCalloway

Dept of Marine SciencesDept of Marine Sciences

UNC Chapel HillUNC Chapel Hill

ADCP Raw Data

Currents Data

Proc Waves(Python) pressure.txt

orbitals.txtranges.txtsysinfo.txt

Splitter(Python)

Radial to uvw(matlab)

Waves Data

Data structure Ready for DIWASP

DIWASP(matlab)

Directional WaveSpectral Matrix

ADCP Directional Wave Processing

Specmultiplot(matlab)

DIWASPDIWASP Directional Wave Spectral ToolboxDirectional Wave Spectral Toolbox

Created by David Johnson (Centre of Water Research, Created by David Johnson (Centre of Water Research, University of Western Australia)University of Western Australia)

Edited by Greg Dusek as of 08/2007Edited by Greg Dusek as of 08/2007 Changed matlab spectral density function csd to cpsdChanged matlab spectral density function csd to cpsd Added the ability to input the along beam radial Added the ability to input the along beam radial

velocitiesvelocities Added the ability to plot multiple spectra on one page Added the ability to plot multiple spectra on one page

InputsInputs Surface ElevationSurface Elevation PressurePressure Current Velocity ComponentsCurrent Velocity Components Surface Slope ComponentsSurface Slope Components Water Surface Vertical VelocityWater Surface Vertical Velocity Water Surface Vertical AccelerationWater Surface Vertical Acceleration Along Beam Radial Velocities (recently added)Along Beam Radial Velocities (recently added)

DIWASP cont.DIWASP cont. Estimation Methods AvailableEstimation Methods Available

DFTM- Direct Fourier Transform MethodDFTM- Direct Fourier Transform Method EMLM-Extended Maximum Likelihood MethodEMLM-Extended Maximum Likelihood Method BDM-Bayesian Direct MethodBDM-Bayesian Direct Method IMLM-Iterated Maximum Likelihood MethodIMLM-Iterated Maximum Likelihood Method EMEP-Extended Maximum Entropy MethodEMEP-Extended Maximum Entropy Method

Can Also Choose:Can Also Choose: Directional ResolutionDirectional Resolution Frequency ResolutionFrequency Resolution Number of Iterations PerformedNumber of Iterations Performed Type of graphical outputType of graphical output

Current AnalysisCurrent Analysis

Looking at 4 distinct test cases at Bogue Inlet PierLooking at 4 distinct test cases at Bogue Inlet Pier 1200khz ADCP in 8m of water1200khz ADCP in 8m of water Which estimation methods provide the best resultsWhich estimation methods provide the best results How the DIWASP generated wave spectra compare to those created by How the DIWASP generated wave spectra compare to those created by

RDI’s WavesmonRDI’s Wavesmon Comparison at the 8 meter Duck Pressure ArrayComparison at the 8 meter Duck Pressure Array

Data from the Duck Pressure Array and an 1200khz RDI ADCP in the Data from the Duck Pressure Array and an 1200khz RDI ADCP in the same locationsame location

Comparison of spectra from the ADCP processed by RDI’s Wavesmon Comparison of spectra from the ADCP processed by RDI’s Wavesmon and processed by DIWASP to spectra processed independently from the and processed by DIWASP to spectra processed independently from the 8 meter array8 meter array

Comparison between ADCP and AWAC (in progress)Comparison between ADCP and AWAC (in progress) RDI ADCP and Nortek AWAC in the same location at the Bogue Inlet RDI ADCP and Nortek AWAC in the same location at the Bogue Inlet

PierPier Comparison of the spectra generated through the proprietary software Comparison of the spectra generated through the proprietary software

of both instruments to those generated through DIWASPof both instruments to those generated through DIWASP

Bogue Pier Test CasesBogue Pier Test Cases Looking at 4 test cases from ADCP at Bogue PierLooking at 4 test cases from ADCP at Bogue Pier

Large Amplitude, Long Period WavesLarge Amplitude, Long Period Waves Large Amplitude, Small Period Large Amplitude, Small Period Small Amplitude, Long PeriodSmall Amplitude, Long Period Small Amplitude, Small PeriodSmall Amplitude, Small Period

For each test case:For each test case: Two examples of each caseTwo examples of each case Look at IMLM and EMEP estimation methodsLook at IMLM and EMEP estimation methods Use UVW and Pressure data, Range data (Surface Elevation), Use UVW and Pressure data, Range data (Surface Elevation),

and along beam Radial Velocity (transferred to Surface and along beam Radial Velocity (transferred to Surface Displacement)Displacement)

Compare Results to Wavesmon generated spectrumCompare Results to Wavesmon generated spectrum Used a directional resolution of 2 degrees, a frequency Used a directional resolution of 2 degrees, a frequency

resolution of .01Hz and iterations set to 100 for EMEP, and set resolution of .01Hz and iterations set to 100 for EMEP, and set to 3 for IMLMto 3 for IMLM

Used the default settings for Wavesmon: directional resolution Used the default settings for Wavesmon: directional resolution of 4 degrees, a frequency resolution of .078125Hz and the of 4 degrees, a frequency resolution of .078125Hz and the IMLM method with 1 iterationIMLM method with 1 iteration

Bogue Inlet Pier – 1359 March 2, 2007Bogue Inlet Pier – 1359 March 2, 2007Large Amplitude, Long PeriodLarge Amplitude, Long Period

Bogue Inlet Pier – 1359 March 2, 2007Bogue Inlet Pier – 1359 March 2, 2007Large Amplitude, Long PeriodLarge Amplitude, Long Period

EMEP uvwEMEP uvw SigH (meters): 2.19SigH (meters): 2.19 peak period (seconds): 9.0909peak period (seconds): 9.0909 Dir of peak period: 6Dir of peak period: 6 Dominant Direction: 10Dominant Direction: 10

IMLM uvwIMLM uvw SigH (meters): 2.19SigH (meters): 2.19 peak period (seconds): 9.0909peak period (seconds): 9.0909 Dir of peak period: 2Dir of peak period: 2 Dominant Direction: 352Dominant Direction: 352

EMEP Radial VelocitiesEMEP Radial Velocities SigH (meters): 1.84SigH (meters): 1.84 Peak period (seconds): 9.0909Peak period (seconds): 9.0909 Dir of peak period: 270Dir of peak period: 270 Dominant Direction: 12Dominant Direction: 12

EMEP RangeEMEP Range SigH (meters): 2.03SigH (meters): 2.03 peak period (seconds): 9.0909peak period (seconds): 9.0909 Dir of peak period: 6Dir of peak period: 6 Dominant Direction: 8Dominant Direction: 8 IMLM rangeIMLM range SigH (meters): 2.03SigH (meters): 2.03 peak period (seconds): 9.0909peak period (seconds): 9.0909 Dir of peak period: 14Dir of peak period: 14 Dominant Direction: 14Dominant Direction: 14 Wavesmon outputWavesmon output SigH (meters): 2.16SigH (meters): 2.16 peak period (seconds): 9.1429peak period (seconds): 9.1429 Dir of peak period: 355Dir of peak period: 355 Dominant Direction: 359Dominant Direction: 359

Bogue Inlet Pier – 1400 April 4, 2007Bogue Inlet Pier – 1400 April 4, 2007Large Amplitude, Small PeriodLarge Amplitude, Small Period

Bogue Inlet Pier – 1400 April 4, 2007Bogue Inlet Pier – 1400 April 4, 2007Large Amplitude, Small PeriodLarge Amplitude, Small Period

EMEP uvwEMEP uvw SigH (meters): 1.00SigH (meters): 1.00 peak period (seconds): 5peak period (seconds): 5 Dir of peak period: 270Dir of peak period: 270 Dominant Direction: 14Dominant Direction: 14 IMLM uvwIMLM uvw SigH (meters): 0.99SigH (meters): 0.99 peak period (seconds): 5peak period (seconds): 5 Dir of peak period: 36Dir of peak period: 36 Dominant Direction: 38Dominant Direction: 38

EMEP Radial VelocitiesEMEP Radial Velocities SigH (meters): 0.86SigH (meters): 0.86 Peak period (seconds): 5Peak period (seconds): 5 Dir of peak period: 24Dir of peak period: 24 Dominant Direction: 22Dominant Direction: 22

EMEP RangeEMEP Range SigH (meters): 0.92SigH (meters): 0.92 peak period (seconds): 5peak period (seconds): 5 Dir of peak period: 28Dir of peak period: 28 Dominant Direction: 30Dominant Direction: 30

IMLM rangeIMLM range SigH (meters): 0.92SigH (meters): 0.92 peak period (seconds): 5peak period (seconds): 5 Dir of peak period: 30Dir of peak period: 30 Dominant Direction: 30Dominant Direction: 30 Wavesmon outputWavesmon output SigH (meters): 1.05SigH (meters): 1.05 peak period (seconds): 4.92peak period (seconds): 4.92 Dir of peak period: 15Dir of peak period: 15 Dominant Direction: 27Dominant Direction: 27

AnalysisAnalysis

EMEP method seems to generally outperform IMLMEMEP method seems to generally outperform IMLM Using uvw velocities works fairly well with long period Using uvw velocities works fairly well with long period

waves (swell conditions) but has trouble with short period waves (swell conditions) but has trouble with short period waves (wind conditions)waves (wind conditions)

Using the ranges seems to perform very well with shorter Using the ranges seems to perform very well with shorter period waves increasing to some period relative to the period waves increasing to some period relative to the depth. A this point the aperture becomes too small to depth. A this point the aperture becomes too small to resolve the wave direction.resolve the wave direction.

The radial velocities appear to work fairly well, however The radial velocities appear to work fairly well, however there is an unexplained consistent loss of sig wave height. there is an unexplained consistent loss of sig wave height. This does not appear in the following example of the 8m This does not appear in the following example of the 8m array ADCP.array ADCP.

Wavesmon appears to perform fairly well in all conditions Wavesmon appears to perform fairly well in all conditions

8 Meter Duck Pressure Array8 Meter Duck Pressure Array

Data from RDI ADCP and Pressure ArrayData from RDI ADCP and Pressure Array RDI ADCPRDI ADCP

Data processed by RDI’s Wavesmon softwareData processed by RDI’s Wavesmon software Data processed through python and matlab waves Data processed through python and matlab waves

toolbox, using DIWASP to generate spectratoolbox, using DIWASP to generate spectra 8m Pressure Array 8m Pressure Array

Data processed by independent ACE FRF methodData processed by independent ACE FRF method

Comparison of data over timeComparison of data over time Analysis of a two day period sampling every 3 Analysis of a two day period sampling every 3

hours, Feb 01 2007 at 1900 to Feb 03 2007 at hours, Feb 01 2007 at 1900 to Feb 03 2007 at 19001900

Duck, NC at ACE FRFDuck, NC at ACE FRFSignificant Wave Height Significant Wave Height

(Feb 01 2007, 1900-Feb 03 2007, 1900)(Feb 01 2007, 1900-Feb 03 2007, 1900)

Duck, NC at ACE FRFDuck, NC at ACE FRFPeak Period Peak Period

(Feb 01 2007, 1900-Feb 03 2007, 1900)(Feb 01 2007, 1900-Feb 03 2007, 1900)

Duck, NC at ACE FRFDuck, NC at ACE FRFDirection of Peak Period Direction of Peak Period

(Feb 01 2007, 1900-Feb 03 2007, 1900)(Feb 01 2007, 1900-Feb 03 2007, 1900)

Duck, NC at ACE FRFDuck, NC at ACE FRFDominant Direction Dominant Direction

(Feb 01 2007, 1900-Feb 03 2007, 1900)(Feb 01 2007, 1900-Feb 03 2007, 1900)

Duck, NC at ACE FRFDuck, NC at ACE FRF3D Wave Spectra3D Wave Spectra

Feb 01 2007, 1900Feb 01 2007, 1900


Feb 01 2007, 1900Feb 01 2007, 1900


Feb 03 2007, 1000Feb 03 2007, 1000

AnalysisAnalysis

The EMEP method using the radial velocities appears to provide a The EMEP method using the radial velocities appears to provide a very good estimation of the directional wave spectrum over a 2 very good estimation of the directional wave spectrum over a 2 day period.day period.

The IMLM method with the radial velocities consistently performs The IMLM method with the radial velocities consistently performs poorly.poorly.

In comparison to the 8m array this method is generally in In comparison to the 8m array this method is generally in agreement in terms of sig wave height, peak period and directionagreement in terms of sig wave height, peak period and direction

Using the uvw velocities the swell waves can be fairly well Using the uvw velocities the swell waves can be fairly well estimated, however there is no directionality to the wind wavesestimated, however there is no directionality to the wind waves

Using the ranges the wind waves are somewhat resolved, but the Using the ranges the wind waves are somewhat resolved, but the swell waves are less resolved directionallyswell waves are less resolved directionally

The second case shown is a good example to both wind and swell The second case shown is a good example to both wind and swell conditions existing simultaneously and from different directions. conditions existing simultaneously and from different directions. The EMEP radial velocities is fairly accurate when compared to the The EMEP radial velocities is fairly accurate when compared to the 8m array in this example, as is Wavesmon. However, the range 8m array in this example, as is Wavesmon. However, the range and uvw estimation methods have significant trouble resolving and uvw estimation methods have significant trouble resolving both types of waves.both types of waves.

SummarySummary

The ADCPs at both Bogue Pier and at the FRF are at roughly the same The ADCPs at both Bogue Pier and at the FRF are at roughly the same depth and are both 1200khz typesdepth and are both 1200khz types

The results from the Bogue Pier case studies provide for a good basis The results from the Bogue Pier case studies provide for a good basis for understanding which type of estimation method and which sets of for understanding which type of estimation method and which sets of data can provide the best estimations of the wave fielddata can provide the best estimations of the wave field

The results from the comparison at the 8m array have shown that the The results from the comparison at the 8m array have shown that the EMEP method with the radial velocity data seems to perform well in a EMEP method with the radial velocity data seems to perform well in a variety of conditions including those with swell and wind waves presentvariety of conditions including those with swell and wind waves present

Wavesmon has shown to perform well in estimating the wave field in a Wavesmon has shown to perform well in estimating the wave field in a variety of conditions, however, the limitations and “black-box” aspect variety of conditions, however, the limitations and “black-box” aspect of the software makes having a functional alternative desirableof the software makes having a functional alternative desirable

The next step will be to compare the independently processed 8m The next step will be to compare the independently processed 8m array spectra to the spectra generated from running the raw data array spectra to the spectra generated from running the raw data through our processing tool box. through our processing tool box.

At Bogue Pier we now have data from a Nortek AWAC instrument that At Bogue Pier we now have data from a Nortek AWAC instrument that can be compared to the output generated by the ADCP at the same can be compared to the output generated by the ADCP at the same location. This work is in progress.location. This work is in progress.

adcp waves raw data processing greg dusek harvey seim, sara haines, chris calloway dept of marine...

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