Explain the concept of "Coherent Processing" in radar systems.

The concept of "Coherent Processing" in radar systems primarily revolves around the maintenance of phase information between transmitted and received signals. This is crucial because incorporating phase data allows for the accurate differentiation of target movements, speed, and other characteristics.

When signals are coherent, they have a consistent phase relationship, which enables radar systems to effectively exploit the Doppler effect—an essential factor in detecting moving targets. This phase information facilitates improved signal-to-noise ratios since it allows for precise synchronization of the signals, enhancing the overall resolution and performance of the radar. By utilizing coherent processing, radar systems can accurately track the movement of targets over time and discern between multiple targets in the same area.

The other options, while related to radar technology, do not capture the essence of coherent processing. Frequency modulation is an unrelated technique that generally pertains to the way signals are shaped and transmitted. Increasing the operating range typically involves changes in power or antenna design. Measuring changes in target mass is not aligned with the fundamental principles of coherent processing and involves different methodologies altogether.