DislikedThat post was quite a bit later than TopCat description. He did not have the Goertzel algorithm when he first described topcat. Some later posts discuss the coding of the algorithm.
He is defining it this way because he thinks the dominant cycle is the trend, everything else is noise. But using this definition and the Goertzel, you will not get the rapid response shown in the original topcat image because a Goertzel, or any other DFT will not change rapidly enough, since it is an average over a long block. I think his later systems may use the...Ignored
I completely agree with you, it's exactly what I think.
BTW, a clutter filter isn't really equals to SnR indicator, for me it looks more a trend/nontrend indicator, anyone have a source code for this ?