Page History

• Analysis starts with the implementation of EWA within the PyResample open source Python implementation (with some Cython modules for speed)
• The PyResample implementation is based upon the implementation within the MODIS-Swath-to-Grid toolbox developed and distributed by NSIDC.  See: https://nsidc.org/data/user-resources/help-center/what-modis-swath-grid-toolbox-ms2gt-and-what-can-it-do
• MS2GT is based upon an algorithm developed by Green & Heckbert, IEEE, June 1986
  "Creating Raster Omnimax Images from Multiple Perspective Views Using the Elliptical Weighted Average Filter".
  https://ieeexplore.ieee.org/document/4056910
• None of this provides much clarity in defining the image characteristics and performance of the algorithm.
• See also, as an introduction: Forward-Projection and Reverse-Projection Algorithms

The EWA Algorithm for swath data projection is a highly efficient and well-established approach for projecting swath data to a “regular grid”.  It likely also has some possible “off-label” applications to geographically gridded data and data regridding without reprojection (shifting grid alignment and changing resolution).

...