I've been working on some improvements to the internal guider. They are now in the latest git repo and nightly builds and will likely be released with the next KStars release. I'm hoping some adventurous people will try them out and pass on feedback.
First off, I know many people are happy with the current performance, so as the default, nothing should change algorithmically. You should get the same guiding performance as before.
Changes:
SEP MultiStar: This is a new guide-star detection, tracking & drift computation algorithm.
You can select this in the Guide options menu (click Options... in the lower right corner of the Guide tab), and then click on "Guide", and then choose from the "algorithm" menu. There you choose the guide-star detector. (e.g. there choices include Smart, SEP, Fast, ...). Try SEP MultiStar. I believe it is more stable in all three respects (guide star selection, detection and drift calculation). You may not notice much difference in a normal guiding session when things are going well, except, perhaps, better choice of a guide star.
GPG RA Guiding: New control algorithm for RA guiding.
I added a new guiding algorithm. This is for RA only--that is, guiding for DEC still happens, but using the existing guiding algorithms. This guider is based on the work in this PhD thesis
www.research-collection.ethz.ch/handle/20.500.11850/129665 and is the same as the well-regarded Phd2 guide algorithm known as Predictive PEC. You will see Copyright 2014-2017 Max Planck Society, now in the KStars credits for this system. It estimates the periodic error in the guiding system, and tries to "fix it before it happens". This system should perform about the same as the standard guider for the first period or two of your mount's periodic error, then improve. When using this system, it's best to set in advance what your mount's worm-gear period is (e.g see
github.com/OpenPHDGuiding/phd2/wiki/Mount-Worm-Period-Info). I know my Orion Atlas pro is about 480s. You enable this in the Guide options menu, in the GPG RA tab, and then checking "Enable GPG". There are other parameters you can change, but as indicated earlier, the main one to think about is "Major Period".
Graphics: I modified the drift graph on the guider tab in several ways.
(1) Added a guide-star SNR plot. This can be useful, e.g. when the SNR starts taking a dive, you know things aren't going well, perhaps a cloud is passing by.
(2) Added a plot of the RMS error (i.e. RA and/or DEC arc-second error RMS-averaged over the past 50 guiding samples).
(3) Separated the zooming for x and y axes. You can use '+' and '-' buttons below the x-axis to change the time scale of the plot (number of minutes plotted), and you can use the mouse scroll (same as before) to zoom in/out of the Y-axis. When you mouse-over the plot, you can see all the values for the different graphs.
BTW, in case you didn't know (this isn't something I changed), you can change the amount of space allocated to the drift plot (the circle) and the drift graph by placing your mouse over the short dotted line between them and dragging left of right.
Calibration: I added a backlash removal section to the "calibration dance". Before it starts calibrating DEC, the Ekos guider will now take 5 DEC steps, without measurement, to make sure there's no backlash in the DEC gears. This should improve the quality of the calibration, however, if you don't like this, you can remove it by unchecking "Remove DEC backlash in guide calibration" in the Guide options menu, in the "Calibration" tab there.
Calibration Plot and Log viewing: A month ago I made a few other changes I wanted to remind you about, described in this thread:
indilib.org/forum/general/7076-new-inter...der-tools.html#54829 Very briefly, I added a calibration plot and a way to use phdlogview for EKos internal guiding. Please let me know if you have any feedback on those as well.
Hy
PS What's next? I cleared most of my "Guider TODO list", but there's one other thing bugging me. I believe that we should not need to re-calibrate every time we start guiding. In fact, a well-done old calibration is probably better than a recent one that's noisier (as long as the camera angle hasn't rotated). I will likely look into saving and restoring calibrations, and/or on-line calibration, where the guider adapts as it goes.