The computation of a MODIS tile geometry follows the following steps:

  1. Map the tile to an equivalent tile in the upper-right quadrant(UR).
  2. Find if the tile is a fictional tile or a real tile or a degenerate tile. Ignore fictional and degenerate tiles. Degenerate tiles have only one vertex which is a real point. All remaining points of the tile are fictional points
  3. Find the coordinates of the four vertices of the rectangle corresponding to the tile.
  4. Densify each of the four segments of the tile.
  5. Remove fictional points on each of the edges if there are any.
  6. Add the edge-points if the edge has fictional points on one side and real points on another.
  7. Map the densified points back to its original quadrant.
  8. Convert the points from planar coordinates back to geodetic coordinates. Convert from radians to degrees.