Final answer:
The TACS element used to address threats at extended ranges and lower altitudes compared to ground-based radars is AWACS. Enhancements like increasing the power of radar pulses and refining receiver sensitivity are key for improving radar sensitivity.
Step-by-step explanation:
The TACS element that provides the theater with the ability to find, fix, track, and target maritime or airborne threats at lower altitudes and extended range compared to ground-based radars is an Airborne Warning and Control System (AWACS). To improve the sensitivity of a radar system to detect objects at longer ranges, one could increase the power of the transmitted pulse or refine the radar system's receiver sensitivity. Increasing the power of the radar pulse enhances the radar's ability to illuminate distant objects with more energy, thus increasing the chance of detecting the reflected signal. Refining the receiver's sensitivity allows the radar to better distinguish between weak echo signals and noise, enhancing the radar's capability to detect objects at greater distances.