Question about NDP (acoustic profiler) employment for wave measurement

Dear all,

I'm looking for detailed information about how can I extract wave signals from NDP equipment. I've worked hard on NDP data files using  the PUV techinque but the results were not good. Following some questions:

(1) Are the orbital velocity  in the file *.wad (columns 6, 7 and 8) referred to the surface? If no, What is the depth that each beam measures the orbital velocities (x, y and z)?

(3) What is the distance between the pressure sensor and the top (or bottom) of the equipment?

(2) How can I get the NDP manual for detailed information?

Sincerely,

Saulo Meirelles

Hello Saulo,

Before I jump into answering your questions there are some details I need to understand better.  You mention that you are using an NDP, this is an older Nortek product that we no longer sell, is it possible that you are using and Aquadopp or Aquadopp Current meter?  I have never heard of the NDP measuring waves, so this is why I ask.

1) The distance for the orbital velocities for the Aquadopp are referenced to the instrument, and this would be the blanking distance plus the cell size, so it is close to the instrument.  The depth will have to be determined by the mean pressure measurement.

2) The distance of the Pressure sensor for the Aquadopp, Aquadopp Profiler, AWAC, and Vector is just 1-3 cm from the top of the sensor body, so for the purposes of measuring waves you can consider the pressure sensor at the top of the head.

3)  The manuals for Nortek instruments can be found under the "Support" page of the Nortek web site.  If you don not find the manual here for your instrument then please contact us again so we can assist.

kind regards,

Torstein

Thanks for your reply, Mr. Torstein.

Actually, I'm work only on  NDP data which were collected on 2005! The NPD was employed to measure waves in shallow-water-muddy-bottom. Now, I'm trying to analyze  this data  in order to characterize the wave attenuation over soft bottom. The problem is that there are no documentations about how the equipment was settings for the measurements realized in 2005. I have only a header file that show me some important informations, for example, the wave measurements were ENABLE.

I'm using PUV technique to extract wave data, for that reason I need exactly information about how the NDP measured U, V and W direction and pressure.

Unhappily, the manual was not found in "Support" section.

Thanks in advance for your time.

Best regards.

Saulo Meirelles

Hello Saulo,

Do you think you could send me the header file so that we can point you in the correct direction?  The NDP is an instrument that was phased out when I first started working at Nortek (6-7 years ago).  So I need to consult some of the "old gray haired" folk here about where to find the manual

kind regards,

Torstein

Hello Torstein,

Following attached the requested file!

Thanks in advance!

Best regards,

Saulo.