Re Gridding
This wiki page deals with different thoughts with respect to re-gridding of one dataset onto the grid of another. This necessarily touches many topics. The keywords are: resampling, upsampling, downsampling, interpolation, smoothing, aggregation, grids, data representations.
One way to achieve re-gridding is by simply interpolating values of the slave dataset unto the grid of the master dataset. interp utiliy from the basemap package can be used to achieve this:
Matplotlib basemap interp documentation
Basemap interp takes a 2D data point array, with accompanying x and y input grid vectors defining respectively x and y coordinates of the data set, along with two 2D meshgrids that define the new target grid onto which the provided data set should be interpolated to.
This shows nicely what meshgrids are and how they define coordinates:
