See also https://en.wikipedia.org/wiki/Drizzle_(image_processing)
“Drizzle has the advantage of being able to handle images with essentially arbitrary shifts, rotations, and geometric distortion and, when given input images with proper associated weight maps, creates an optimal statistically summed image.” and “Results using the DRIZZLE command can be spectacular with amateur instruments.”
Richard Hook and I were at Oxford together. He recently retired from ESO and we’re in frequent email contact.