Downsampling

Downsampling is used to reduce the sampling rate of data. Shannon's Sampling Theorem must be obeyed, i.e., before you sample, you must low-pass filter the data with a cut-off frequency less than half of the new sampling rate.

Note: If you omit the filtering, the data will be aliased and cannot be corrected.

1. Low-pass filter the data with a cut-off frequency less than half of the new sampling rate by an integer factor.


Decimate the filtered data by the desired factor.

See also: Aliasing, Decimation.