What does resampling mean?
Drawing a fresh set of particles from the old set, each chosen with probability in proportion to its weight, so that unlikely guesses are dropped and likely ones are copied. Afterwards all the weights are equal again.
In a lesson
After a few updates, almost all the weight sits on a handful of particles and the rest are wasting compute on guesses that have been ruled out. Resampling fixes that: draw a new set of particles from the old one, in proportion to their weights.
Learn it
- Taught in U7.5 Resampling Localisation, University