Reprocessing Wave Data at Breezy Point

June 9, 2009

We took the data from CODAR at Breezy Point, New York during the period February 7 2007  to December 30 2007 and reprocessed it using the settings as shown in the figure. The program used was Release 5 Update 4. The CODAR data will be compared to  the RDI ADCP.

Noise Floor Measurements from SEAB and CDDO

This is a plot of the noise floor for the SeaSonde System deployed in Puerto Rico.

This is a plot of the noise floor for the SeaSonde System deployed in Sea Bright, NJ

The average noise floor for this 2 week time period ( February 12-28) is give in this table:

CDDO                      SEAB              Diff

Loop 1           -145                           -152               7 dB

Loop 2           -147                           -151               4 dB

Loop 3           -143                           -157              14 dB

The noise floor is consistently higher at the CDDO site compared to SEAB.

Plot_all_matches

We have work on the code of plot_all_matches.m. This code allows us to obtain the detection rate, rms error and SNR values. I have a table. I am posting the figures that determine in this case (13 mHz using the MAAS trader container ship) which is the best method.

The first figure shows the same FFT for both methods and we are only changing the threshold.

The second figure is a comparison between both methods.

Error Bars

The document “Ship Detection at Codar” states on page 38 “Each instance is
represented by a square (error box) with the half height as the uncertainty (σ by (14)) and
half length as the half FFT window”

So the full length is represented by the full length of the FFT?  Reference 14 is a private communication with Jimmy Isaccson.  Jimmy, can comment on how the standard deviation is calculated?