Vectrino+ Postprocessing [WinADV]

Hello there,

we at the University of Applied Sciences, Darmstadt (Germany) run a Vectrino+ to measure three-dimensional-velocities in our laboratory.

I would like to use WinADV beside Matlab for postprocessing the velocity data but the problem is that the fileconverter (v1.02) which you provide doesn`t convert the files (*.vno) correctly. The file converter says "Incorrect file or conversion" or, if choosing another format I`ll get files with the size of zero bytes.

By the way: If somebody has the problem that the file converter doesn`t start correctly and shut immediately down in cause of missing dll's:

Just put the missing *.dll in the folder where the converter is being installed. (if they aren't already in \Windows\System32\)

In our case that were:

- mfc71.dll

- msvcp71.dll

- msvcr71.dll

(I think they`re part of the MS Visual C++ Runtime libraries)

Further it would be nice if you can give us a few hints for optimizing measurements.

The main parameters we look at are the SNR and the correlation, during most of our measurements they are at 15-20 db and 65-90 %, depending on the turbulence. i think that`s ok.

Greetings,

Dipl. Math. Sven Bickelhaupt

Department of Hydraulics Research

University of Applied Sciences, Darmstadt

Hi Sven,

  I'll admit I haven't used the FileConverter application before, but I think the problem might be if you aren't using Polysync to collect the data initially. There are a few differences in the binary format between a file produced by Polysync and a file produced by the Vectrino+ software.

Could that be the problem?

P.J.

In terms of optimizing measurements, 15-20 dB for SNR is good. Correlations of 65-90% are potentially problematic, especially fur turbulence work since as correlation decreases noise increases. I would recommend playing around with the velocity range to try and improve correlation. If that's not an option and you're simply measuring a very turbulent flow, decorrelation might be unavoidable. In either case, a power spectrum will give you a good indication of wether you are measuring turbulence or just noise.

P.J.

Thanks,

in view of the differences in the binary i thought that, too.

But is there a workaround /possibility to process the data recorded by the vectrino+ in WinADV?

The Changelog from WinADV says:

"Version 2.015 and later can load files recorded by Nortek Vectrino probes"

Till now i use my own Matlab Routine which reads all ASCII-files from the measurement folder,

then the "bad" values are sorted out and a mean in (x,y,z)-Direction is being calculated. 

But i like to see the performance of the filters in WinADV, too because I think it`s a well developed piece of software.

We take measurements in a 1:5 scale model of a fish pass and we have still a few problems with the accuracy of the velocities.

I used a higher velocity range in the vectrino software to get a better correlation but the velocities didn`t fit to the ones which

are recorded by a hydrometric impeller. The calculations of the scale model are fitting really good to the measurements with the impeller, but the ADV-measurements not really.

Can it be that the velocity from the ADV in x-direction change from one sample to another in a range from 1.0 m/s to -0.5 m/s?

(SNR and Correlation looks still good!)

Till now, I`m not convienced of the measurements we made, but i have hope that other filters produce better results.

Sven

Previously P.J. Rusello wrote:

Hi Sven,

  I'll admit I haven't used the FileConverter application before, but I think the problem might be if you aren't using Polysync to collect the data initially. There are a few differences in the binary format between a file produced by Polysync and a file produced by the Vectrino+ software.

Could that be the problem?

P.J.

 

But is there a workaround /possibility to process the data recorded by the vectrino+ in WinADV?

In the Vectrino+ software, there is a file conversion utility (what you've used previously to export the ASCII files). If you select the NDV option in the dialog that pops up prior to export a *.adv file will be produced you can use with WinADV.

The Changelog from WinADV says:

"Version 2.015 and later can load files recorded by Nortek Vectrino probes"

We unfortunately don't have anything to do with WinADV so I can't really say much about what it's doing. But, the Vectrino binary file format has been published in our System Integrator's Guide available here: http://www.nortek-as.com/en/support/application-development

I'm not sure if the developer has updated it to natively read the *.vno file format instead of having to jump through the *.adv format hoop. It should be fairly simple to enable this however.

Can it be that the velocity from the ADV in x-direction change from one sample to another in a range from 1.0 m/s to -0.5 m/s?

(SNR and Correlation looks still good!)

This sounds like some data quality problems. A change from -0.5 to 1 m/s is entirely unrealistic physically. It definitely sounds like you will need to do some filtering to remove outliers. WinADV has built in methods for this and there are several other published methods. There are numerous posts on the forums regarding the efficacy of various methods, but I've honestly never seen a comparison showing one method is better than any other. I find my preferred method of an adaptive Gaussian filter quite reliable and easily tunable as needed.

Anyway, I would spend a bit more time with data (especially outlier) screening and you should see improved results and better agreement between the two instruments and model.

P.J.