Digital Signal Filtering
The Digital Signal Filtering tool can be used to remove target frequency bands or oscillations from a signal using a Low Pass, High Pass, Band Pass, or Band Stop filter.
Using the Digital Signal Filtering Tool
Select the signal to search: From the dropdown menu select a signal from the details pane, pinned items or recently used sections.
Specify the filter type: Choose to filter using a Low Pass Filter, High Pass Filter, Band Pass Filter or Band Stop Filter.
Specify the cutoff(s): The cutoff is the filter threshold. Enter a time period (e.g. 10min) or frequency (e.g. 0.001667Hz).
Advanced Options
Specify the window size: If you don’t specify this size, it will be automatically set to 4 times the cutoff (or upper cutoff).
Specify the sampling rate: The spacing between samples output by this filter. If you don’t specify this value, Seeq will calculate it automatically based on the signal you select.
Filter Types
Low Pass
Filter a signal to attenuate (smooth) waveform features with frequencies above (or periods below) a supplied cutoff and retain features with frequencies below (or wave periods above) the cutoff. Uses a Blackman-windowed sinc filter and finite impulse response.
Frequencies above (or wave periods below) the specified cutoff are filtered, while frequencies below (or periods above) are not filtered.
High Pass
Filter a signal to attenuate (smooth) waveform features with frequencies below (or periods above) a supplied cutoff and retain features with frequencies above (or wave periods below) the cutoff. Uses a Blackman-windowed sinc filter and finite impulse response.
Frequencies below (or wave periods above) this threshold are filtered, while frequencies above (or periods below) are not filtered.
Band Pass
Filter a signal to retain waveform features with frequencies (or periods) between two supplied cutoffs and attenuate (smooth) features with frequencies (or periods) outside the cutoffs. Uses a Blackman-windowed sinc filter and finite impulse response.
For this tool two cutoffs are specified.
For the lower frequency (or upper wave period), frequencies above (or wave periods below) this threshold are retained, while frequencies below (or periods above) are filtered out.
For the upper frequency (or lower wave period), frequencies below (or wave periods above) this threshold are retained, while frequencies above (or periods below) are filtered.
Band Stop
Filter a signal to attenuate (smooth) waveform features with frequencies (or periods) between two supplied cutoffs and retain features with frequencies (or periods) outside the cutoffs. Uses a Blackman-windowed sinc filter and finite impulse response.
For this tool two cutoffs are specified.
For the lower frequency (or upper wave period), frequencies below (or wave periods above) this threshold are retained, while frequencies above (or periods below) are filtered out.
For the upper frequency (or lower wave period), frequencies below (or wave periods above) this threshold are retained, while frequencies above (or periods below) are filtered.