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Available CODAR Data
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Standard CODAR
Real-Time Data
The raw surface current is the unprocessed
data measured by CODAR. Therefore these velocity fields are the summation
of all sources of current, including tides and wind.
This vector field represents the component of the raw velocity that is caused by tidal forcing. Using a least squares approximation, the following constituents
were used to calculate the tidal velocity fields:
- Half a Lunar Day (Period = 12.42 Hours)
- Half a Solar Day (Period = 12.00 Hours)
- A Lunar Day (Period = 25.82 Hours)
- Luni-Solar (Period = 23.93 Hours)
- Larger Lunar Elliptic (Period = 12.66 Hours)
The detided vector field contains all the surface currents shown in the raw velocity field with the exception of the tidal currents. Using the above periods, a predicted tide is calculated and then subtracted
from the raw data field.
The low-pass surface current field
is representative of the second step of data processing. A low-pass filter
is applied to the detided data to further eliminate any other currents with a period less than 30 hours. The data is delayed three hours because the filter needs
information up to three hours after the time of calculation.
These high frequency currents are calculted by subtracting the low-pass field from the detided field. Therefore, These currents have periods less than thirty hours and do not include the tides.
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