Nyquist theorem significance in telemetry sampling?

• A. Sampling rate at least twice the maximum frequency of the signal to avoid aliasing.
• B. Sampling rate equal to the maximum frequency.
• C. Sampling is unnecessary in telemetry.
• D. Nyquist theorem relates to encoding.

Answer: (A)

Nyquist sampling means you must sample at least twice the highest frequency present in the signal to reconstruct it accurately and avoid aliasing. In telemetry, signals from sensors or channels have a finite bandwidth, so you apply an anti-aliasing filter to limit that bandwidth and choose a sampling rate at or above twice that limit. Sampling any slower than twice the highest frequency causes higher-frequency content to fold into lower frequencies, distorting the data. That’s why the statement about sampling at least twice the maximum frequency to prevent aliasing is the correct choice. The other ideas—sampling being unnecessary, sampling exactly at the maximum frequency, or Nyquist relating to encoding—don’t describe how to prevent aliasing or how the data is accurately captured and reconstructed.