Grating Lobe Suppression of Non-Periodic Geometric Formations Based on Modified Particle Swarm Optimization

For the issue of configuration difficulty in maintaining linear formations based on the same orbital plane for distributed space-based coherent aperture radar (DSCAR), it is necessary to modify the linear formation model into an arc formation model. This article derives the steering vector and joint pattern expressions for DSCAR based on uniform arc formation, and designs a segmented inertial factor (IF) particle swarm optimization (PSO) to seek the optimal solution for non-uniform spacing and random yaw angle in non-periodic geometric distribution. Simulation analysis shows that the combination of non-uniform spacing and random yaw angle in non-periodic geometric formations can achieve lower peak side lobe level (PSLL) compared to single non-uniform spacing and single random yaw angle but with wider beamwidth spread. Additionally, the segmented IF PSO proposed in this article balances convergence more quickly in the early stage of the search process and improves convergence speed to approach the optimal value (OV) in later stage. Compared with other IF PSO, it has better convergence speed and accuracy.