On Mon, 29 Jun 2009 12:30:36 -0700, Rune Allnor wrote:

> On 29 Jun, 20:57, "Michael Plante" <michael.pla...@gmail.com> wrote:
>
>> >Apart from that, don't dismiss the bandpass filter quite yet. True,
>> >there might be some delays, but if you are a bit cautious when
>> >designing the filter, you would be able to correct for them.
>>
>> Hrm. Â*Okay, would you say the BPF is the best option mentioned so far?
>
> Let's say the BPF or LP is the 'least bad' option so far. There are a
> few too many loose ends to suggest other options. As always, start with
> the simple, easy-to-use stuff first. Only when that is insufficient,
> switch to more heavy-duty stuff.
>
> PLLs and Kalmans and what have you, might be what is needed in the end,
> but it would just be too stupid starting up those sorts of machineries
> whithout having at least tried the simple filters first.
>
> Rune

The only thing that I may add is that if you really do have hours of data
collected at 100Hz, and if your frequencies of interest really only
extends to 0.5Hz, you may wish to consider some easy decimation before
you really start wringing out your data. Even on a PC 720000 data points
can take a while to process...

Having said that, I still think I'd do my initial investigation with
"raw" data -- I'd probably just do an FFT and wait for it, then plot the
spectrum up to a couple of Hz and see what's there.

--
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