> In the table of Zernike coefficients from Roddier, the bottom entry is "Orders
Sup. nanometres rms". I observe that enabling/disabling this term has a
significant effect on performance values.
>
> What is this term? What effects/aberrations are eliminated from the analysis
when it is disabled?
>
These are the higher-order aberrations or residuals after
the other listed Zernikes are subtracted off. It will
contain narrow zones, edge effects, bumps, holes, or
anything else the software was not able to fit with the
Zernikes. Its the stuff that is left-over. If the mirror
has a rough figure, there might be some significant amount
of these.
Hello Group, I am trying the Roddier software on images from my 13" F4 Newtonian. So far I get a crash when I try to open the images. Images are edited in...
... Gert - I suggest downloading IRIS (freeware) and, after processing and saving (presumably as .FIT) in AstroArt, load into IRIS and immediately save as...
Group - here is a hopefully interesting question for the collective wisdom: Background: I have been actively considering the construction of an "indoor...
Hi, Keeping in mind that I haven't done anything with Roddier : - Can the 2120 be set up on something like Polaris and have it's SA characterized by Roddier?...
... From: m_hollimon To: roddier@yahoogroups.com Sent: Saturday, June 06, 2009 6:26 PM Subject: [roddier] Artificial Star Question Group - here is a hopefully...
Ron Watson
ronald_watson@...
Jun 6, 2009 11:12 pm
Hi Mick, This is a very good question. I have done alot of visual star testing and some Roddier in this mode using a scope as a collimator to provide an...
... Dr. Biretta - it's certainly good to hear from you again; hope the WFPC3 begins to work well soon. Of course I was much afraid the above would be the...
... Hi Mick, First, I have enjoyed reading your posts over the months detailing your experience with Roddier. John Biretta and I often observe together and...
... Mr. Leuba - thanks much for the encouragement. The impetus in all this is not to attack or demean Roddier but to try to get Roddier and interferometry to...
... Hi Mick, I tried to get a quick look at your earlier results on SA. One interesting item I noticed is that Roddier and your interferometry seem to roughly...
... Dr. Biretta - thanks much for the examination of some of the previous test results. I am going to carefully re-examine the later test stuff (T6, T7, T8)...
Hi Mick, ... I had just looked at the first of the T6 results you had. If I isolate the spherical term, using the check boxes in Roddier 0.4 / Front d'onde /...
... Dr. Biretta - thanks again for the quick look. Armed with improved insights (as a result of your quick look at T6/0DegA), I reexamined said image pair...
Dr. Biretta - in all the blather of post #673 I completely forgot to ask an important question: In the table of Zernike coefficients from Roddier, the bottom...
... These are the higher-order aberrations or residuals after the other listed Zernikes are subtracted off. It will contain narrow zones, edge effects, bumps,...
... Dr. Biretta - thanks, I understand. Peculiar that I get a 0.02-0.04 Strehl improvement by turning them off; the mirror shouldn't have much roughness...
Dr. Biretta/Group - A careful further examination of the data in the comparison table of post # 673, plus some investigation into how the performance numbers...
Hi Mick, I'm trying to follow along the numbers in these recent posts. Couple random questions.... So you are doing interferometry at the radius of curvature,...
... Dr. Biretta - sorry for any confusion about some of these details. All the Zernike coefficients displayed by OpenFringe are normalized,i.e., an error...
... The above mods have been completed and a set of Roddier images (Test 9) obtained and analyzed using Vega as the target star. ... A "fanatically careful"...
Only a point. I used Vega last year for Roddier test of a Klevstov-Cassegrain (TAL 250K). In my conclusion, it's too bright for a correct testing (I also...
... Oscar - an interesting point. Seems like this effect would also modify results for refractors but they generally test closer to expectations. Curious. I...
Group - in post #680 I raised two questions about the interaction between camera sensor chip orientation and Roddier analysis results. I have so far found no...
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