The EWA Algorithm for swath data projection is a highly efficient and well-established approach for projecting Earth-Observational swath data to a “regular grid”. It likely also has some possible “off-label” applications to projecting geographically gridded data and general data regridding - without reprojection (shifting grid alignment and changing resolution). Another possible application would be to general reprojection of projected grids.
The “ellipse of influence” provides an important technique for calculating the area of influence, in the target grid. It is an efficient way of finding target cells when forward projecting the source data grid to the output grid. This permits a reasonably efficient “forward navigation” approach, versus more typical reverse projection algorithms.