| Weibull Fit MCP Algorithm | |
The 'Weibull Fit' algorithm is an MCP algorithm proposed by van Lieshout (2010). It uses a power law model of the form:
where x denotes observed reference site wind speeds and y denotes observed target site wind speeds.
To calculate the exponent, Windographer calculates the Weibull shape factors of the two datasets and calculates their ratio:
The scale factor is equal to the Weibull scale factor at the target site divided by the Weibull scale factor at the reference site, raised to the exponent b:
The graph below shows an example of a Weibull Fit curve fit with a decidedly non-linear character. Note that it follows from the curve fit equation that the line of best fit will always pass through the origin.
If you choose multiple direction sectors, Windographer will subdivide the concurrent data by direction sector and calculate the exponent and scale factor separately for each sector. It uses the reference direction sensor to determine the direction sector.
Similarly, if you choose multiple yearly divisions, Windographer will also subdivide the concurrent data according to month. If you choose 4 yearly divisions, for example, then January-March data will go in the first subdivision, April-June in the second, July-September in the third, and October-December in the fourth.
See also