I have accelerometer signal, which is preprocessed by the actigraph on-device. Original sampling rate is 32 Hz, but activity count is summed for every minute, so I have a signal with 1 measurement per minute.
For denoising and to analyze long-term dependencies (my data spans several days), especially related to circadian rhythm, I aggregate this data for each hour, taking the mean. After this I have a signal with 1 measurement per hour.
Libraries for analysis of frequency features, e.g. Scipy or TSFEL require sampling rate as a parameter, e.g. for calculating periodogram.
What should be my sampling rate after all this processing?
- 32 Hz, since original measurements were gathered with this frequency?
- 1 Hz, since as a part of very basic preprocessing (and since I don't care about minor movements and analysis of short term effects) a total activity per minute was calculated?
- 1/3600 Hz, since after aggregating by hour I have one measurement per hour?
- it depends on purpose and results and no single answer is totally right or wrong?