There is no anti-aliasing filter in the hardware, however there is filtering available in the software.
The lowpass filtering algorithm is chosen according to the relationship between the selected cut-off frequency (fC) and the sampling rate (fS), as shown in the following description.
fC / fS
0.0 to 0.1
Filter type:- Moving average
A moving average filter is used for low cut-off frequencies. The length of the filter is adjusted to achieve the selected cut-off frequency, which is is defined as the first minimum in the frequency response. There is significant signal leakage above the cut-off frequency. This filter changes a vertical edge into a linear slope.
0.1 to < 0.5
Filter type:- FIR
A finite impulse response filter is used for medium to high cut-off frequencies. This has a monotonic roll-off above the cut-off frequency and therefore suffers from less leakage than the moving average filter.
You can force PicoScope to use one or other of the filter types by adjusting the Samples control in the Capture Setup toolbar to make the ratio fC/fS fall into one of the two ranges described. As the description shows, the cut-off frequency must be below half the sampling frequency.