Low-frequency resonance passive identification method and device for offshore large metal target

The invention relates to the technical field of positioning or existence detection adopting reflection or re-radiation of radio waves, in particular to a low-frequency resonance passive identification method and device for a large offshore metal target. The method comprises the steps of determining a low-frequency resonance detection frequency and a channel for detecting the large-scale marine target according to the scale of the large-scale marine target, a current ionosphere state and an electromagnetic environment, and receiving a low-frequency resonance scattering signal by using a pre-constructed wide-area distributed multi-frequency cooperative receiving system, and carrying out resonance target identification on the marine large-scale target in a frequency domain and a time domain through analysis, and carrying out mutual verification on two identification results to obtain a verification result, thereby obtaining an actual identification result of the marine large-scale metal target. According to the