Massachusetts - Modelled Wind Speed Grid - MassGIs

The original grids were subjected to the ArcInfo GRIDPOINT function, generating point coverages of cell centroids retaining the wind speed data. The points were then clipped to a boundary representing an aggregate of the land area of Massachusetts, the offshore state waters (3 mile buffer), and ocean sanctuary areas that also constitute state waters. This data was then projected into the Mass. Stateplane NAD83 projection (meters).

For EOEEA project-specific purposes, the point attribute data was transferred onto a statewide vector grid (vectorized fishnet representation of a raster) with a resolution of 250 meters, and a geographic extent encompassing the previously described clip boundary, rounded to the nearest 1,000 meters. This was done to allow storage of multiple attributes in a single dataset (a limitation of raster-based data is that it only allows the storage of a single grid value), and to facilitate vector-based analyses with data that have also been processed and transferred to the same index grid. The original points were separated by a distance of 200 meters and oriented slightly askew to the vector grid generated in the Massachusetts Stateplane Mainland Meters projection, occasionally resulting in more than one point existing in a single 250m x 250m vector cell. For those cells that had more than one point within their areas, the average of their wind speeds at that altitude and location were calculated and stored in the attributes.

MassGIS projected the original data from WGS_1984 to Mass. State Plane Mainland NAD83 Meters, resulting in a slight resampling (nearest-neighbour) of the original data.