A method for box regularized particle filtering, used to predict a state of a system, is modified such that it can be implemented in a parallel manner. The modification concerns a step of redistributing state intervals and in particular a determination of a number of sub-intervals intended to replace each state interval. The method is particularly suitable for being implemented in a navigation system with measurement correlation, for example an aircraft navigation system using ground-correlation, and for being executed by a field-programmable or fixed-gate array circuit.