Sensor Array is a technology that can be researched at the Command Center in Tech Level 3. It costs 300 Food and 200 Nova, and gives buildings +4 Line of Sight. Sensor Beacon must be researched before it becomes available.
Like the previous technology, this is a useful improvement, but not particularly game-changing.
"At Tech Level 3, you can boost your buildings' lines of sight once again with the Sensor Array."