Focus on overlap, not gaps. Divide the grid into zones that double‑cover each other. For each zone assign a primary and secondary tracker; if one fails the other takes over immediately. Use threat ranking—high value targets trigger full‑auto, lower ones stay on passive watch. Keep the software modular so you can swap out a failing component without taking the whole system offline. The key is to make every sensor a backup for at least one other, and vice versa.