History Question

Hello, I was just inquiring about  a statement on the nortek-as website. In the history/innovation page it says that the Aquadopp was the first instrument to combine measuring currents and waves (via PUV) in 2001.  Is this the first time an acoustic doppler current meter was used to estimate waves?  I am just wondering because I would like to know for a paper and I cannot seem to find any real statement in some literature.  I think maybe there was one paper:
Krogstad, H.E., R.L. Gordon and M.C. Miller (1988): High resolution directional wave spectra from horizontally-mounted acoustic Doppler current meters. J. Atmos. and Oceanic Technol., 5, 340-352.

which is the first I have seen where they use this technology. I realize this forum may not be for these questions, but just curious and I appreciate any feedback.

Ok, I did some more research. Perhaps the paper mentioned above was the first use of horizontally mounted current meters to estimate wave direction.  More specifically, is this the first published experiment to use acoustic Doppler current meters to estimate wave parameters?

[4] E.A. Terray, H.E. Krogstad, R. Cabrera, R.L.
Gordon and A. Lohrmann (1990): Measuring
wave direction using upward-looking Doppler
sonar. Proc. IEEE 4th Working Conference. on
Current Measurement, IEEE Press, 252-257

Hi

The Aquadopp profiler was the first commercial system to alternate between current profiling and PUV wave measurements but the application of the MLM processing for wave (directional) measurements precedes this.  The maximum likelihood method, which forms the basis for the AWAC wave directional calculations, was developed independently in the 1980s by Dr. Harald Krogstad at NTNU in Norway and by a group at the Japanese Port and Harbor Research institute lead by Drs. Takayama, Nagai and Hashimoto.  The work in Japan was later reformulated into a Japanese patent that was submitted in 1994 and is currently held by Kaijo Corporation (among others).  The Nortek implementation of the directional estimates incorporated in the AWAC is based in its entirety on early work by Dr. Krogstad  " />'>  

Here are some more references:

Hashimoto et al. (1996): Improvement of submerged Doppler-type directional wave meter and it applciation to field observations. Coastal Engineering 629-642

Pinkel R. et al (1987): Open Ocean surface wave measurement using Doppler sonar. JAOT V.5 No 4:340-352

Smith J.A. et al (1995) Directional surface measurements estimates from Doppler sonar data.  JAOT V.12:617-632

Best regards,

Atle Lohrmann