Expendable active decoys, expendable active decoys against radio frequency tracking missiles; expendable active decoy systems, expendable active decoy systems against radio frequency tracking missiles; countermeasures against missiles, countermeasures against radio frequency tracking missiles; countermeasure systems, countermeasure systems against missiles, countermeasure systems against radio frequency tracking missiles; digital radio frequency memory based countermeasures; digital radio frequency memory based expendable active decoys; digital radio frequency memory systems, digital radio frequency memory based countermeasure systems, digital radio frequency memory based expendable active decoy systems; electronic warfare systems; electronic warfare countermeasures; electronic attack systems.