PCSpec reads initialization data
from a file named PCSpec.DAT containing one line with six constants
separated by commas. These
Maximum factor to use for compensation of water column attenuation.
Nominal distance from the sea floor to the pressure and current
meter sensors (in meters). For a MacroSpec/620, this is 1 m.
Frequency cut-off above which all spectral bins are set to zero.
Output type as explained below.
Number of direction bins. This
should be greater than zero if using a MacroSpec, and zero for all other
Constant to convert from units of psi to units of water depth.
This constant should include the specific gravity of water, e.g. to
get mks units in standard sea water, the constant is 0.72416 assuming a
specific gravity of 1.03. Note
that the PCSpec energy units will be m2s.
The three output options are as
- Only summary statistics are printed, such as significant wave height,
peak period, etc.
- Summary statistics and the unidirectional discrete spectra are printed
for 32 frequency bins. If the
specified number of direction bins is greater than five, then the output
also includes the directional spreading coefficients for each frequency
bin. The coefficients can be
used to generate the discrete direction spectra, D(f,q),
using equation 1.
- Summary statistics and the entire discrete directional spectra are
printed for specified number of direction bins and 32 frequency bins.
= p / 2 S(f) / C5 (1 + 2 A cos (p
/ 2 - q - y1
) + 2 B cos (p - 2q
= tan-1 (C2 / C1 );
y2 = tan - 1 (C4
/ C3 )
A = Ö(C12
+ C22 );
B = Ö(C32
+ C42 )
and the Ci (i =
1...5) are given in the out put file for each frequency bin, S(f) is the
discrete 1-D spectra for frequency bin f, and q
is the compass heading.