Mod 2.2 Interpolation

 

This week I used the Thiessen Polygons, Spline, and IDW(above) interpolation methods to make a water quality map of Tampa Bay. IDW took the points that measured the biochemical oxygen demand(BOD) and assumed that the closer a raster cell was to the point, the more similar it's BOD would be. Thiessen Polygons creates polygons where inside is closer to its associated point than to any other point input feature.Finally, Spline uses an interpolation method that estimates values using a mathematical function that minimizes overall surface curvature, resulting in a smooth surface that passes exactly through the input points. Regularized splines modifies the minimization criteria so third-derivative terms are incorporated into the minimization criteria. Tension on the other hand, option modifies the minimization criteria so first-derivative terms are incorporated into the minimization criteria.