Current political situation and counter-terrorist measures lead to the majority of warfare being carried out locally, and, as a rule, in densely populated areas. This trend formed the grounds for developing new artillery and mortar systems and updating older ones with guided munitions. The necessity of employing guided munitions, in its turn, is due to high mobility of contemporary weapon systems and improvements in their protection. Given that artillery and mortar munitions are small in size and have to be well-suited for mass production, be simple in design and boast low production costs, their guidance system should be cheap, simple, reliable and at the same time able to ensure high efficiency of target defeat. The article deals with the problem of defeating a target with a given accuracy in the case of insufficient prior information on its actual position. It must be noted that an impulse correction system features a fixed value of the correction push, which leads to the issues of "under-" or "over-correction". We suggest introducing a multilevel correction system to solve this non-trivial problem, employing correction engines of varied thrust.