OutputOpt (Output Options)
Used to define the values which will be stored. All output options for this instruction result in an output array. The elements of the array have “_WVc(n)” as a suffix, where n is the element number. The array uses the name of the Speed/East variable as its base. For details on wind speed and unit vector calculations, see Wind Vector Calculations.
| Value | Description |
|---|---|
| 0 | Mean horizontal wind speed (WVc(1)), unit vector mean wind direction (WVc(2)), and standard deviation of wind direction (WVc(3)). Standard deviation is calculated using the Yamartino algorithm. This option complies with EPA guidelines for use with straight-line Gaussian dispersion models to model plume transport. |
| 1 | Mean horizontal wind speed (WVc(1)) and unit vector mean wind direction (WVc(2)). |
| 2 | Mean horizontal wind speed (WVc(1)), mean wind vector magnitude (WVc(2)), resultant mean wind direction (WVc(3)), and standard deviation of wind direction (WVc(4)). Standard deviation is calculated using the Campbell Scientific wind speed weighted algorithm. Use of the mean wind vector magnitude is not recommended for straight-line Gaussian dispersion models, but may be used to model transport direction in a variable-trajectory model. |
| 3 | Unit vector mean wind direction (WVc(1)). |
| 4 | Unit vector mean wind direction (WVc(1)) and standard deviation of wind direction (WVc(2)). Standard deviation is calculated using Campbell Scientific's wind speed weighted algorithm. Use of the mean wind vector magnitude is not recommended for straight-line Gaussian dispersion models, but may be used to model transport direction in a variable-trajectory model. |
The FieldNames instruction can be used to assign individual labels to the elements in the array. In addition, when FieldNames is used, the units for the Direction outputs will be listed as Degs in the data table header. The first output, speed, will reflect the Units designation for that variable if one is present in the program. If Units is not designated, the units field for that variable in the data table header will be blank. Note that a separate variable with a Units assignment can be dimensioned for wind speed, and that variable can be used in the FieldNames instruction; for example,
FieldNames ("mean_wind_speed, mean_wind_direction, std_wind_dir")
Dim mean_wind_speed : Units mean_wind_speed = m/s