[time-nuts] decimation versus decimation

[Magnus Danielson]

Hi Dana,

On 2020-02-25 15:55, Dana Whitlow via time-nuts wrote:
> I'm confused:
>
> I seem to see multiple (at least double) meanings for the term
> 'decimation'.
>
> One meaning is simply: "take every nth sample and discard
> the others without regard to possible aliasing".
This is sub-sampling. It performs a very crude decimation, full with
aliasing.
> The other meaning is: "take every nth sample, but first prefilter
> as appropriate to (sensibly) eliminate aliasing".

This is what every day decimation is these days.

>
> Which is it?  And if the answer is "both", then shouldn't we all
> be very careful to explicitly specify which meaning applies to
> the situation at hand whenever we use the term "decimation"?

Luckily there is different terms for the two different processes to use.

Cheers,
Magnus