What process is not necessary with digitized beacon and primary radar systems like the ASR-11?

• A. Synchronization
• B. Calibration
• C. Modulation
• D. Filtering

Answer: (B)

With digitized beacon and primary radar systems like the ASR-11, the data flow relies on timing, waveform handling, and noise management. Synchronization ensures the transmitter and receiver clocks are aligned so that each returned echo is placed in the correct range and Doppler window, which is essential for accurate measurements. Modulation remains necessary because the transmitted waveform—whether pulsed, coded, or otherwise shaped—determines how you resolve targets and extract information from the echoes, even when everything is digitized. Filtering is critical after digitization to reduce noise and clutter and to pull out true aircraft returns from background signals. Calibration, while still important for overall accuracy and during maintenance, is not a routine processing step in the live data path for these digitized systems; the system relies on automatic self-calibration and maintenance procedures rather than performing a separate calibration during normal operation.