Level 2 data, that is saved in the NetCDF group "L2_cleaned", are the full resolution, cleaned and despiked parameters from level 1. The initial data set is subdivided in sections and labeled accordingly in the parameter SECTION_NUMBER with integers. Level 2 data is ready for estimating spectra. In addition to cleaned and despiked level 1 data channels, level 2 data comprises the additional parameter summarized in the table below.
It is important that the platform speed with respect to water, as used in the dissipation estimates, is included in this level. Also note that the shear probe time series (and optionally acceleration and vibration) must be cleaned and filtered as needed at this level, and will not be altered further when estimating dissipation rates.
Dimensions
| Dimension |
Description
|
| TIME |
length of the record from turbulence (fast) data channels
|
| N_SHEAR_SENSORS |
number of shear channels (shear sensors)
|
| N_***_SENSORS [math]\displaystyle{ ^a }[/math] |
number of *** channel (sensors)
|
[math]\displaystyle{ ^a }[/math] Example dimension names would be: N_VIB_SENSORS for vibration (piezo-acceleration) sensors, N_ACC_SENSORS for
vibration acceleration sensors.
Variables
| Variable Name |
Req.[math]\displaystyle{ ^a }[/math] |
Standard Name |
Units of measurement |
Dimensions
|
| TIME |
R |
time |
CF-Convention[math]\displaystyle{ ^b }[/math] |
TIME
|
| SHEAR |
R |
[sea][math]\displaystyle{ ^c }[/math]_water_velocity_shear |
s-1 |
TIME, N_SHEAR_SENSORS
|
| PSPD_REL |
R |
platform_speed_wrt_[sea][math]\displaystyle{ ^c }[/math]_water |
m s-1 |
TIME
|
| SECTION_NUMBER |
R |
unique_identifier_for_each_section_ of_data_from_timeseries |
- |
TIME
|
| VIB |
HR |
platform_vibration |
m s-2, or -[math]\displaystyle{ ^d }[/math] |
TIME, N_VIB_SENSORS
|
| ACC |
O |
platform_acceleration |
m s-2, or -[math]\displaystyle{ ^d }[/math] |
TIME , N_ACC_SENSORS
|
[math]\displaystyle{ ^a }[/math]: Code for the requirement of variable, R: Required, HR: Highly recommended, O: Optional
[math]\displaystyle{ ^b }[/math]: Unit and offset need to be compatible with the Climate and Forecast (CF)-convention
[math]\displaystyle{ ^c }[/math]: User can choose between water or sea_water depending on the environment
[math]\displaystyle{ ^d }[/math]: Acceleration and vibration sensors are sometimes not calibrated and their records are used as raw values.
Return Dataset requirements for shear probes
go to previous: Level 1 data
go to next: Level 3 data.
