BZ UMa model and CLEANest

Over the last few days I finished coding and unit testing the multi-period analysis CLEANest algorithm implementation in VStar (again, translated from TS). The main missing parts were allowing the user to specify “variable” and “locked” periods in addition to selecting them from a DC DFT period analysis result. I’m at the point where I need feedback.

Apart from the unit tests that show equivalence with the TS program, I’ve been “playing” with a few different datasets and pre-whitening, modelling, CLEANest.

In my last post, I created  a model based upon two periods found through successive refinement (pre-whitening). Tonight I used CLEANest to obtain those periods for a model with fewer steps.

Starting from the DC DFT frequency scan (low frequency: 0, high frequency: 50, resolution: 0.01) of the BZ UMa V band data, we end up (as last time) with a top hits table like this:

Selecting two periods for CLEANest from BZ UMa DC DFT top hits

Selecting two periods for CLEANest from BZ UMa DC DFT top hits

Also shown is that I have selected the two values used in the two-period model last time before clicking the CLEANest button giving us:

Two periods with same power added by CLEANest to BZ UMa DC DFT top hits

Two periods with same power added by CLEANest to BZ UMa DC DFT top hits

The CLEANest algorithm inserts two new rows at the top with the same highest power. I have selected these above. Switching to the “Power vs Frequency” (power spectrum) tab we see:

Two periods from CLEANest superimposed as "spikes" on BZ UMa DC DFT periodogram

Two periods from CLEANest superimposed as "spikes" on BZ UMa DC DFT periodogram

Notice the spikes showing the refined frequencies from the CLEANest algorithm. Switching back to the Top Hits tabbed pane, clicking “Create Model”, we get:

Two period BZ UMa model from CLEANest

Two period BZ UMa model from CLEANest

I am still quite new to period analysis, including CLEANest (it’s one thing to code it, another to apply it…), so I’m interested in feedback from others regarding the appropriateness of CLEANest in a context like this, and also first impressions regarding usability.

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