Data Decimation
Signal decimation involves discarding specific data points and potentially low-pass filtering the result to create a lower-density digital sequence. The application of sampling rate reduction decreases the computational load on downstream processors and reduces the storage requirements for long-term data logging. It is a standard procedure when a high-speed acquisition system captures more data than the final application requires.
Alias Prevention
A digital anti-aliasing filter must be applied before any data points are removed. This sampling rate reduction requires that the new Nyquist frequency remains higher than the bandwidth of the signal of interest. Failure to filter the data results in high-frequency noise folding back into the lower frequency range and corrupting the measurement.
Proper filter design ensures that the signal remains valid throughout the transformation.
Processing Efficiency
Reducing the data rate allows for more complex algorithms to be executed in real time. The lower data volume after sampling rate reduction permits the use of more efficient filters.
Signal Integrity
Validation of the decimation process involves comparing the spectral content of the signal before and after the change. This confirms that sampling rate reduction has not introduced artifacts into the measurement data. The goal is to preserve the information contained in the original sequence while minimizing the resources required to process it.
