A system for detecting signals emitted by an emitter, said system comprising: at least one receiver system including: at least one antenna configured to receive electromagnetic radiation emitted by said emitter and to transform said received electromagnetic radiation into an electric received signal; a receiver, coupled with said at least one antenna, said receiver configured to sample said electric received signal to produce real-time received signal samples; a memory, coupled with said receiver, configured to store at least one signal characteristic relating to the radio signal transmitted by said emitter, said memory further configured to store previously acquired signal samples; a detector, coupled with said receiver and with said memory, configured to attempt to detect a signal relating to an emitter from said real-time received signal samples, by employing said at least one stored signal characteristic relating to the radio signal transmitted by said emitter, said detector further configured to attempt to detect a signal relating to an emitter from said previously acquired signals samples at least according to at least one new signal characteristic, thereby improving the signal to noise ratio of said receiver system. at least one receiver system including: at least one antenna configured to receive electromagnetic radiation emitted by said emitter and to transform said received electromagnetic radiation into an electric received signal; a receiver, coupled with said at least one antenna, said receiver configured to sample said electric received signal to produce real-time received signal samples; a memory, coupled with said receiver, configured to store at least one signal characteristic relating to the radio signal transmitted by said emitter, said memory further configured to store previously acquired signal samples; a detector, coupled with said receiver and with said memory, configured to attempt to detect a signal relating to an emitter from said real-time received signal samples, by employing said at least one stored signal characteristic relating to the radio signal transmitted by said emitter, said detector further configured to attempt to detect a signal relating to an emitter from said previously acquired signals samples at least according to at least one new signal characteristic, thereby improving the signal to noise ratio of said receiver system. at least one antenna configured to receive electromagnetic radiation emitted by said emitter and to transform said received electromagnetic radiation into an electric received signal; a receiver, coupled with said at least one antenna, said receiver configured to sample said electric received signal to produce real-time received signal samples; a memory, coupled with said receiver, configured to store at least one signal characteristic relating to the radio signal transmitted by said emitter, said memory further configured to store previously acquired signal samples; a detector, coupled with said receiver and with said memory, configured to attempt to detect a signal relating to an emitter from said real-time received signal samples, by employing said at least one stored signal characteristic relating to the radio signal transmitted by said emitter, said detector further configured to attempt to detect a signal relating to an emitter from said previously acquired signals samples at least according to at least one new signal characteristic, thereby improving the signal to noise ratio of said receiver system.