Synthetic Aperture Radar (SAR) across swarms of small drones enables satellite-grade terrain imaging at a fraction of the cost. However, independent local oscillator phase drift blurs radar imagery. We present closed-loop phase-stabilizing firmware.
Distributing a coherent 10 GHz microwave reference over a secondary digital tracking beam locks the mixer phase of slave UAVs to the master transmitter, enabling millimeter imaging resolution.
Flight tests over forested terrain demonstrated 0.15-meter ground resolution imaging, proving that distributed low-cost drone swarms match the fidelity of multi-million dollar military satellites.