Air Target Detection from GNSS Forward Scattering Radar: Simulation and Experiment

In this work, the method of air target detection using GNSS forward scattering radar(FSR) was theoretical and experimental researched. Based on the analysis of the impact of the target's electrical size and velocity on the diffraction effect of GNSS signals, a framework for air target detection using GNSS FSR and target detection operator based on detecting-sequence-anomaly were proposed. Finally, the demonstrating experiment was carried out using BeiDou B3I signals. The results of experiment show that when electrically small-size targets slowly traverse the line of sight(LOS) between the receiver and satellites, the GNSS diffraction signal evolve in a W-shape, whereas they change in a V-shape when the targets are moving at high speeds. Although the diffraction signals of electrically lager-sized targets evolve in V-shape regardless of whether they are moving slowly or quickly, the V-shape evolution of fast-moving targets is modulated by rapid fluctuations. The proposed target detection operator is sensitive to targets and can detect targets through a threshold judgement method. For the experiments with BeiDou B3I signals, the non-target detection operator follows the Weibull distribution, and when the given are 0.6 and 0.3, respectively, the corresponding false alarm probabilities are respectively 6.17x10(-5) and 1.18x10(-4).