Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Bob via time-nuts
: Tue, Feb 25, 2020 7:41 am Subject: Re: [time-nuts] decimation versus decimation The Ancient Romans had another, not so nice, definition. 73, Dick, W1KSZ On Tue, Feb 25, 2020 at 7:56 AM Dana Whitlow via time-nuts < time-nuts@lists.febo.com> wrote: > I'm confused: > > I seem

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread William H. Fite via time-nuts
Precisely, Dick! On Tuesday, February 25, 2020, Richard Solomon via time-nuts < time-nuts@lists.febo.com> wrote: > The Ancient Romans had another, > not so nice, definition. > > 73, Dick, W1KSZ > > On Tue, Feb 25, 2020 at 7:56 AM Dana Whitlow via time-nuts < > time-nuts@lists.febo.com> wrote: >

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Dana Whitlow via time-nuts
Please note that I have little real interest in measuring ADEV. My interest lies almost solely in measuring phase variations of a received signal via some propagation path, not in any statistical sense but looking at actual waveforms plotted as phase versus time. I am working towards measurement

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Anders Wallin via time-nuts
Some of the confusion might come from different measurement systems dealing with different data, either phase (in seconds), or frequency (fractional). Sub-sampling works for phase-data, just throw away the in-between samples and look at phase samples that are tau-distance apart. Decimation works

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Dana Whitlow via time-nuts
Let's see if I have this correct, then: "Decimation" refers to the two-step procedure (filtering followed by picking every nth sample), and "Sub-sampling" (or "downsampling") properly refers to taking every nth sample and discarding the rest. Is this correct? And thanks for all the responses.

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread George Watson via time-nuts
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Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Bob kb8tq via time-nuts
Hi If you take a look at how ADEV has been traditionally done for many decades, they *do* indeed “decimate without the filter”. There is no re-filtering process as you go from 1 to 2 to 10,000 second tau. Bob > On Feb 25, 2020, at 10:33 AM, Hal Murray via time-nuts > wrote: > > >> One

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Richard Solomon via time-nuts
The Ancient Romans had another, not so nice, definition. 73, Dick, W1KSZ On Tue, Feb 25, 2020 at 7:56 AM Dana Whitlow via time-nuts < time-nuts@lists.febo.com> wrote: > I'm confused: > > I seem to see multiple (at least double) meanings for the term > 'decimation'. > > One meaning is simply:

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Hal Murray via time-nuts
> One meaning is simply: "take every nth sample and discard the others without > regard to possible aliasing". > The other meaning is: "take every nth sample, but first prefilter as > appropriate to (sensibly) eliminate aliasing". > Which is it? Unless you are doing something tricky, it

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Alex Pummer via time-nuts
in original -- Latin -- it means;  take every tenth 73 KJ6UHN  Alex On 2/25/2020 7:15 AM, Bob kb8tq via time-nuts wrote: Hi In the common vernacular “decimation” does indeed mean “just throw the rest away”. You can find papers where that *is* what’s being done with samples and that term is

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Bob kb8tq via time-nuts
Hi In the common vernacular “decimation” does indeed mean “just throw the rest away”. You can find papers where that *is* what’s being done with samples and that term is used. Downsample also means “just throw them away”…… Bob > On Feb 25, 2020, at 9:55 AM, Dana Whitlow via time-nuts >

Re: [time-nuts] decimation versus decimation

2020-02-25 Thread Magnus Danielson via time-nuts
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.