Sea-Bird Spectra File Format


The ASCII spectra files in the Sea-Bird format have file names based on deployment number and gauge location - Inlet gauge (S=Shallow) Outside gauge (D=Deep). For example the file for the inlet gauge on deployment #3 is named OI_SbSpec_3S.txt. These files have a 2 line header with spectral statistics followed by lines of spectra data.

The first line contains (starting with a '*'):

Item #

Description

1

Burst number

2

Start of wave burst, seconds since 1 Jan 1989 (+ 3 days)*

3

Wave integration time

4

Number of points in wave burst

5

Number of spectral estimates in each frequency band

6

Water depth (m)

7

Pressure sensor depth (m)

8

Density (kg/m3)

9

Chi-squared confidence interval (percent)

10

Multiplier for Chi-squared lower bound

11

Multiplier for Chi-squared upper bound


The second line contains:

Item #

Description

1

Number of frequency bands calculated

2

Frequency of the first frequency band (Hz)

3

Interval between frequency bands, delta-f, (Hz)

4

Total variance (m2 )

5

Total energy (Joules/m2 )

6

Significant period (s)

7

Significant wave height (m)


Subsequent lines have the auto-spectral density for each frequency (m2/Hz).